JP2013113603A - Microwave imaging system and imaging processing method - Google Patents

Microwave imaging system and imaging processing method Download PDF

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JP2013113603A
JP2013113603A JP2011257384A JP2011257384A JP2013113603A JP 2013113603 A JP2013113603 A JP 2013113603A JP 2011257384 A JP2011257384 A JP 2011257384A JP 2011257384 A JP2011257384 A JP 2011257384A JP 2013113603 A JP2013113603 A JP 2013113603A
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reflected wave
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wave signal
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Atsushi Mase
淳 間瀬
Naoki Ito
直樹 伊藤
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Kyushu University NUC
Maxell Holdings Ltd
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Hitachi Maxell Ltd
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Abstract

PROBLEM TO BE SOLVED: To provide a microwave imaging system capable of suitably imaging and evaluating a situation of a detection target by removing reflected wave components on the surface of an object by respectively using reflected wave signals of ultrashort pulses from the object and its model and surely acquiring a reflected wave component from the masked detection target in the object.SOLUTION: A main reflected wave signal acquired in a state that an object 50 is covered with a cover 80 simulated to an object surface shape is compared with a sub reflected wave signal acquired in a state that an object model manufactured by using a material with a dielectric constant similar to that of the object 50 is covered by signal analysis means 13, and a reflected wave component of the main reflected wave signal from a detection target can be relatively emphasized by canceling a reflected wave component of the main reflected wave signal from the surface part by a reflected wave component of the sub reflected wave signal from the surface part. Consequently imaging of the detection target can be accurately executed and the detection target can be suitably detected from an image obtained by image reconstruction.

Description

本発明は、照射した超短パルスの周波数帯域における物質の誘電率の差異に基づいて生じる反射波を用いて、周囲の物体とは性質の異なる検出対象物を画像として検出可能とするマイクロ波イメージングシステムに関する。   The present invention uses a reflected wave generated based on a difference in dielectric constant of a substance in the frequency band of an irradiated ultrashort pulse, and enables microwave imaging that enables detection of an object to be detected having different properties from surrounding objects. About the system.

医療用途において生体内情報を画像化（イメージング）する手法としては、Ｘ線や超音波を利用した方法の他、核磁気共鳴画像法も知られており、これらは広く利用されているが、特に、乳がん検出を目的とする場合には、Ｘ線マンモグラフィが最も有用なイメージング法として近年利用が進んでいる。   As a technique for imaging in vivo information in medical applications, in addition to methods using X-rays and ultrasound, nuclear magnetic resonance imaging is also known, and these are widely used. For the purpose of detecting breast cancer, X-ray mammography has recently been used as the most useful imaging method.

ただし、Ｘ線マンモグラフィでは、透過力の低いＸ線を使用し、その照射強度も比較的小さい上、Ｘ線の周波数領域において正常な胸部細胞と腫瘍との誘電率の差異が小さく、得られた画像における正常な胸部組織と腫瘍とのコントラストが小さくなり、これらの見分けが付きにくいことに起因して、画像に基づく診断結果が偽陰性や偽陽性となる割合が高くなるといった問題がある。また、Ｘ線マンモグラフィでは、小さい放射線量で***の病変を撮影する必要から、***を専用の器具で圧迫して厚みを極力薄くする必要があり、これに伴い受診者が痛みを感じる場合があるという問題もあった。   However, in X-ray mammography, X-rays with low penetrating power were used, the irradiation intensity was relatively small, and the difference in dielectric constant between normal breast cells and tumors was small in the X-ray frequency range. There is a problem that the contrast between the normal breast tissue and the tumor in the image is small, and it is difficult to distinguish between these, and there is a problem that the diagnostic result based on the image has a high rate of false negative or false positive. In addition, in X-ray mammography, it is necessary to photograph breast lesions with a small dose of radiation, so it is necessary to compress the breast with a dedicated instrument to make the thickness as thin as possible, and the patient may feel pain accompanying this. There was also a problem.

これに対し、マイクロ波の周波数帯域で正常な胸部組織と悪性腫瘍との誘電率の差が大きくなることを利用して、マイクロ波帯域の超短パルスレーダを用いて胸部からの反射波を取得し、反射波の飛行時間を計測して***内の腫瘍の検出と位置同定を行ういわゆるマイクロ波イメージングを用いた乳がん検出の手法が近年提案され、超短パルスを用いた非接触での測定により、Ｘ線マンモグラフィで生じていた諸問題を解決できるものとして、注目を集めている。こうした従来のマイクロ波イメージングを用いた乳がん検出の手法の一例として、特表２００８−５３０５４６号公報に開示されるものもある。   On the other hand, taking advantage of the difference in dielectric constant between normal breast tissue and malignant tumor in the microwave frequency band, the reflected wave from the chest is acquired using an ultra-short pulse radar in the microwave band. In recent years, breast cancer detection methods using so-called microwave imaging that detect and locate tumors in the breast by measuring the time of flight of reflected waves have been proposed. Attention has been focused on solving various problems that have arisen in X-ray mammography. An example of such a conventional technique for detecting breast cancer using microwave imaging is disclosed in JP-T-2008-530546.

特表２００８−５３０５４６号公報Special table 2008-530546 gazette

従来のマイクロ波イメージングによる乳がん検出の方法は、前記特許文献に示されるものとなっており、マイクロ波イメージングにおける最大の問題としての、体表面からの極めて大きい反射波の成分が体内の腫瘍検知の大きな障害となる点への対策として、反射波から校正信号を生成して反射波における体表面での反射波成分を打消す手法が提案されているが、この場合、表面での反射波成分を打消す対象の反射波と同じアンテナではなく、他のアンテナで得られた反射波に基づいて校正信号が生成されることから、反射波の表面での反射波成分と校正信号とを一致させることは難しく、表面での反射波成分を適切に打消せるとは限らないという課題を有していた。   The conventional method for detecting breast cancer by microwave imaging is shown in the above-mentioned patent document, and the largest problem in microwave imaging is that the component of extremely large reflected waves from the body surface is used to detect tumors in the body. As a countermeasure against the major obstacle, a method has been proposed to generate a calibration signal from the reflected wave and cancel the reflected wave component on the body surface in the reflected wave. Since the calibration signal is generated based on the reflected wave obtained by another antenna, not the same antenna as the reflected wave to be canceled, the reflected wave component on the surface of the reflected wave must match the calibration signal. It is difficult to properly cancel the reflected wave component on the surface.

このように表面反射の影響は、マイクロ波イメージングの手法における大きな問題として存在し、表面反射の影響を回避する他の手法としては、反射波の処理対象とする時間範囲を絞って表面での反射波成分を取除くことも提案されているが、アンテナからの照射パルスがそもそも理想のパルス波形となっておらず、アンテナの周波数特性（分散特性）の影響を受けたチャープパルスとなり、リンギング等を有する状態となっていることから、理想パルスであれば体内の腫瘍等からの反射波成分と見分けられる表面での反射波成分も、現実にはパルスの後に前記リンギング等の後に続く波形を有するものとなっており、この波形部分に内部からの反射波成分が重なって隠されてしまい、時間の範囲を限定するだけではこの内部からの反射波成分のみを有効に取得することはできないという課題を有していた。   In this way, the effect of surface reflection exists as a major problem in microwave imaging techniques. As another technique for avoiding the influence of surface reflection, reflection on the surface can be performed by narrowing down the time range for processing the reflected waves. It is also proposed to remove the wave component, but the irradiation pulse from the antenna is not an ideal pulse waveform in the first place, it becomes a chirp pulse influenced by the frequency characteristics (dispersion characteristics) of the antenna, and ringing etc. Since it is in an ideal state, if it is an ideal pulse, the reflected wave component on the surface that can be distinguished from the reflected wave component from the tumor etc. in the body also actually has a waveform that follows the ringing etc. after the pulse The reflected wave component from the inside overlaps with this waveform part and is hidden, and only by limiting the time range, the reflected wave component from the inside is formed. It has been a problem that can not be acquired only effectively.

本発明は、前記課題を解消するためになされたもので、二つの物体の表面形状が似ている場合、超短パルスの反射波信号における表面での反射波成分は、二つの物体の材質が異なっていても、誘電率が近い場合、同程度のレベルとなることを利用して、対象物検出を行おうとする物体とそのモデルの反射波信号をそれぞれ用いて物体表面での反射波成分を除去し、マスキングされていた検出対象物からの反射波成分を確実に取得して、物体内の検出対象物の状況を適切に画像化して評価可能とする、マイクロ波イメージングシステム、及びそのイメージング処理方法を提供することを目的とする。   The present invention has been made to solve the above-described problems. When the surface shapes of two objects are similar, the reflected wave component on the surface of the reflected wave signal of the ultrashort pulse is the material of the two objects. Even if they are different, if the dielectric constant is close, the level will be the same, and the reflected wave component on the object surface will be calculated using the reflected wave signal of the object to be detected and its model. Microwave imaging system capable of reliably acquiring the reflected wave component from the detection object that has been removed and masked, and appropriately imaging and evaluating the state of the detection object in the object, and its imaging processing It aims to provide a method.

本発明に係るマイクロ波イメージングシステムは、周波数成分がマイクロ波帯域に及ぶ超短パルスを、内部に誘電率の異なる検出対象物が存在するか又は存在すると予想される所定の物体に対し複数方向から照射し、複数方向の反射波の測定結果を用いて、合成開口処理を伴う画像再構成を実行し、前記物体内における検出対象物の位置を画像化するマイクロ波イメージングシステムにおいて、前記物体に対し超短パルスを複数方向から同時に又は順次時間をずらして照射すると共に、各照射方向ごとに物体や検出対象物からの反射波を受信し、反射波の信号を出力するパルス送受信手段と、前記パルス送受信手段から出力された反射波信号を記録する信号記録手段と、当該信号記録手段から読出される一の反射波信号と、新たに前記パルス送受信手段から出力されるか、前記信号記録手段から別途読出される、他の反射波信号とを比較解析する信号解析手段とを備え、前記一の反射波信号が、前記物体表面と略同じ形状に形成された誘電体製のカバーを被せた前記物体について、前記パルス送受信手段で超短パルスを照射して得られる各方向ごとの所定時間にわたる反射波信号である主反射波信号、及び、前記物体の誘電率に近い誘電率となる材料を用いて形成された前記物体のモデルに、前記カバーを被せたものについて、前記パルス送受信手段で超短パルスを照射して得られた各方向の所定時間にわたる反射波信号である副反射波信号、のいずれか一方であり、前記他の反射波信号が、前記主副の各反射波信号の他方であり、前記信号解析手段が、前記主反射波信号における表面部からの反射波成分を、前記副反射波信号における表面部からの反射波成分で打消し、検出対象物からの反射波成分が相対的に強調された主反射波信号を画像再構成用の新たな反射波信号とするものである。   In the microwave imaging system according to the present invention, an ultrashort pulse whose frequency component covers the microwave band is detected from a plurality of directions with respect to a predetermined object in which a detection target having a different dielectric constant exists or is expected to exist. In a microwave imaging system that irradiates and performs image reconstruction with synthetic aperture processing using measurement results of reflected waves in a plurality of directions, and images the position of a detection target in the object, Pulse transmission / reception means for irradiating ultrashort pulses from multiple directions simultaneously or sequentially, receiving a reflected wave from an object or a detection target for each irradiation direction, and outputting a reflected wave signal; and the pulse Signal recording means for recording the reflected wave signal output from the transmission / reception means, one reflected wave signal read from the signal recording means, and a new pulse Signal analysis means for comparing and analyzing other reflected wave signals output from the receiving means or read out separately from the signal recording means, wherein the one reflected wave signal has substantially the same shape as the object surface A main reflected wave signal which is a reflected wave signal over a predetermined time in each direction obtained by irradiating an ultrashort pulse with the pulse transmitting / receiving means for the object covered with a dielectric cover formed in Predetermined in each direction obtained by irradiating an ultrashort pulse with the pulse transmission / reception means for the object model formed using a material having a dielectric constant close to that of the object and covering the cover One of the sub reflected wave signals that is a reflected wave signal over time, the other reflected wave signal is the other of the main and sub reflected wave signals, and the signal analyzing means includes the main reflected wave signal. In signal The reflected wave component from the surface part is canceled out by the reflected wave component from the surface part in the sub-reflected wave signal, and the reflected wave component from the detection object is relatively emphasized for the main reflected wave signal for image reconstruction. This is a new reflected wave signal.

このように本発明においては、パルス送受信手段から出力された反射波信号をいったん信号記録手段に記録して、この記録された反射波信号と別の反射波信号との比較解析を信号解析手段で実行可能とし、対象物の検出を行おうとする物体にこの物体表面形状を模したカバーを被せた状態で取得した主反射波信号と、物体に近い誘電率の材料を用いて製作された物体モデルにカバーを被せた状態で取得した副反射波信号とをそれぞれ比較すると、物体内部やモデル内部からの反射波成分については信号強度の大きな差が生じるものの、カバーを同様に被せられて略同一形状となっている表面部での反射波成分については、同様の信号強度となることを用いて、信号解析手段で主反射波信号における表面部からの反射波成分から副反射波信号における表面部からの反射波成分を差引き、検出対象物からの反射波成分を残しつつ表面での反射波成分を打消している。これにより、主反射波信号における検出対象物からの反射波成分にほとんど影響を与えずに、効率よく表面での反射波成分を取除いて、主反射波信号での検出対象物からの反射波成分を相対的に強調できることとなり、物体表面での反射波成分の存在に関わりなく検出対象物からの反射波成分を確実に取得でき、画像再構成で検出対象物の画像化を精度よく実行可能となり、得られた画像から検出対象物を適切に検出することができる。   As described above, in the present invention, the reflected wave signal output from the pulse transmission / reception means is once recorded in the signal recording means, and the signal analysis means performs comparative analysis between the recorded reflected wave signal and another reflected wave signal. An object model manufactured using a main reflected wave signal acquired with a cover simulating this object surface shape on an object to be detected and the object to be detected, and a material having a dielectric constant close to that of the object Compared to the sub-reflected wave signals acquired with the cover on, the signal intensity of the reflected wave components from the inside of the object or model is greatly different. With respect to the reflected wave component at the surface portion, the signal analysis means changes the reflected wave component from the surface portion in the main reflected wave signal to the sub reflected wave signal by using the same signal intensity. Subtracting the reflected wave component from the kicking surface portion, and cancel the reflected wave component of the surface while leaving a reflected wave component from the detection object. As a result, the reflected wave component from the detection target in the main reflected wave signal is efficiently removed without affecting the reflected wave component from the detected object in the main reflected wave signal. The component can be relatively emphasized, the reflected wave component from the detection target can be reliably acquired regardless of the presence of the reflected wave component on the object surface, and the imaging of the detection target can be accurately performed by image reconstruction. Thus, the detection target can be appropriately detected from the obtained image.

また、本発明に係るマイクロ波イメージングシステムは、周波数成分がマイクロ波帯域に及ぶ超短パルスを、内部に誘電率の異なる検出対象物が存在するか又は存在すると予想される所定の物体に対し複数方向から照射し、複数方向の反射波の測定結果を用いて、合成開口処理を伴う画像再構成を実行し、前記物体内における検出対象物の位置を画像化するマイクロ波イメージングシステムにおいて、前記物体に対し超短パルスを複数方向から同時に又は順次時間をずらして照射すると共に、各照射方向ごとに物体や検出対象物からの反射波を受信し、反射波の信号を出力するパルス送受信手段と、前記パルス送受信手段から出力された反射波信号を記録する信号記録手段と、当該信号記録手段から読出される一の反射波信号と、新たに前記パルス送受信手段から出力されるか、前記信号記録手段から別途読出される、他の反射波信号とを比較解析する信号解析手段とを備え、前記一の反射波信号が、前記物体について、前記パルス送受信手段で超短パルスを照射して得られる各方向ごとの所定時間にわたる反射波信号である主反射波信号、及び、前記物体表面と略同じ形状に形成された表面部を有する誘電体製の前記物体のモデルについて、前記パルス送受信手段で超短パルスを照射して得られた各方向の所定時間にわたる反射波信号である副反射波信号、のいずれか一方であり、前記他の反射波信号が、前記主副の各反射波信号の他方であり、前記信号解析手段が、前記主反射波信号における表面部からの反射波成分を、前記副反射波信号における表面部からの反射波成分で打消し、検出対象物からの反射波成分が相対的に強調された主反射波信号を画像再構成用の新たな反射波信号とするものである。   Further, the microwave imaging system according to the present invention includes a plurality of ultrashort pulses whose frequency components span the microwave band for a predetermined object in which a detection target having a different dielectric constant exists or is expected to exist. In a microwave imaging system that irradiates from a direction and performs image reconstruction with synthetic aperture processing using measurement results of reflected waves in a plurality of directions, and images the position of a detection target in the object. Irradiating ultrashort pulses from multiple directions simultaneously or sequentially, receiving a reflected wave from an object or detection target for each irradiation direction, and outputting a reflected wave signal; and Signal recording means for recording the reflected wave signal output from the pulse transmitting / receiving means, one reflected wave signal read from the signal recording means, Signal analyzing means for comparing and analyzing with other reflected wave signals output from the pulse transmitting / receiving means or read out separately from the signal recording means, wherein the one reflected wave signal is the pulse for the object. A main reflected wave signal that is a reflected wave signal over a predetermined time in each direction obtained by irradiating an ultrashort pulse with a transmitting / receiving means, and a dielectric made of a dielectric having a surface portion formed in substantially the same shape as the object surface For the object model, the reflected wave signal is a reflected wave signal for a predetermined time in each direction obtained by irradiating an ultrashort pulse with the pulse transmitting / receiving means, and the other reflected wave signal Is the other of the main and sub reflected wave signals, and the signal analyzing means uses a reflected wave component from the surface portion of the main reflected wave signal as a reflected wave component from the surface portion of the sub reflected wave signal. Strike And one in which the reflected wave component from the detection object is a new reflected wave signal for relatively enhanced image reconstructed primary reflected wave signal.

このように本発明においては、パルス送受信手段から出力された反射波信号をいったん信号記録手段に記録して、別の反射波信号との比較解析を信号解析手段で実行可能とし、対象物の検出を行おうとする物体について取得した主反射波信号と、物体の表面形状に略一致する表面形状を有する物体モデルについて取得した副反射波信号とをそれぞれ比較すると、物体内部やモデル内部からの反射波成分については信号強度の大きな差が生じるものの、同様の形状である表面部での反射波成分については同様の信号強度となることを用いて、信号解析手段で主反射波信号における表面部からの反射波成分から副反射波信号における表面部からの反射波成分を差引き、検出対象物からの反射波成分を残しつつ表面での反射波成分を打消している。これにより、主反射波信号における検出対象物からの反射波成分にほとんど影響を与えずに、効率よく表面での反射波成分を取除いて、主反射波信号での検出対象物からの反射波成分を相対的に強調できることとなり、物体表面での反射波成分の存在に関わりなく検出対象物からの反射波成分を確実に取得でき、画像再構成で検出対象物の画像化を精度よく実行可能となり、得られた画像から検出対象物を適切に検出することができる。   As described above, in the present invention, the reflected wave signal output from the pulse transmitting / receiving means is once recorded in the signal recording means, and comparison analysis with another reflected wave signal can be executed by the signal analyzing means, thereby detecting the object. The main reflected wave signal acquired for the object to be performed is compared with the sub reflected wave signal acquired for the object model having a surface shape that approximately matches the surface shape of the object. Although there is a large difference in the signal intensity for the component, the signal analysis means uses the same signal intensity for the reflected wave component on the surface portion having the same shape, so that the signal reflected from the surface portion in the main reflected wave signal The reflected wave component from the surface portion in the sub-reflected wave signal is subtracted from the reflected wave component to cancel the reflected wave component on the surface while leaving the reflected wave component from the detection target. As a result, the reflected wave component from the detection target in the main reflected wave signal is efficiently removed without affecting the reflected wave component from the detected object in the main reflected wave signal. The component can be relatively emphasized, the reflected wave component from the detection target can be reliably acquired regardless of the presence of the reflected wave component on the object surface, and the imaging of the detection target can be accurately performed by image reconstruction. Thus, the detection target can be appropriately detected from the obtained image.

また、本発明に係るマイクロ波イメージングシステムは必要に応じて、前記カバーが、当該カバーをなす誘電体材料中での超短パルスの照射波及び反射波における実効波長の１／４に相当する寸法の厚さとされるものである。   In the microwave imaging system according to the present invention, if necessary, the cover has a dimension corresponding to ¼ of the effective wavelength of the irradiation wave and reflected wave of the ultrashort pulse in the dielectric material forming the cover. The thickness is assumed to be.

このように本発明によれば、カバーの厚みを、超短パルスの照射波における、カバーをなす誘電体媒質中での実効波長の１／４に相当する寸法として、カバー表面と裏面の間の多重反射に起因する反射波の干渉効果により、反射波を相殺する状態を得ることにより、各反射波信号における表面部の反射波成分を減少させることとなり、主反射波信号と副反射波信号の各表面での反射波成分をより確実に打消して、打消しで得られる新たな反射波信号における表面部での反射波成分に起因する不要成分をより一層低減でき、主反射波信号における検出対象物からの反射波成分の存在をより一層明確化でき、反射波信号より得た検出対象物からの反射波成分に基づく画像再構成等処理を正確に実行して、確実に検出対象物の存在に対応した画像を得られる。   Thus, according to the present invention, the thickness of the cover is set to a dimension corresponding to ¼ of the effective wavelength in the dielectric medium forming the cover in the irradiation wave of the ultrashort pulse. By obtaining the state of canceling the reflected wave due to the interference effect of the reflected wave caused by multiple reflection, the reflected wave component of the surface portion in each reflected wave signal is reduced, and the main reflected wave signal and the sub reflected wave signal are reduced. The reflected wave component on each surface can be canceled more reliably, and unnecessary components due to the reflected wave component on the surface in the new reflected wave signal obtained by cancellation can be further reduced, and detection in the main reflected wave signal Presence of the reflected wave component from the object can be further clarified, and processing such as image reconstruction based on the reflected wave component from the detected object obtained from the reflected wave signal is accurately executed to ensure the detection object The image corresponding to existence It is.

また、本発明に係るマイクロ波イメージングシステムは必要に応じて、前記カバーが、前記物体より比誘電率の高い誘電体材料で形成されるものである。   In the microwave imaging system according to the present invention, the cover is formed of a dielectric material having a relative dielectric constant higher than that of the object, if necessary.

このように本発明によれば、カバーを物体より比誘電率の高い誘電体材料で形成して、高い比誘電率に伴う波長短縮効果によってカバー中での超短パルスの照射波及び反射波における実効波長を小さくし、この小さくした実効波長に対応してカバーの厚さも小さく形成できることにより、カバー表面で入射波と反射波が相殺する状態を確保しつつ、カバーの厚さを小さくできる分、カバーの軽量化が図れ、取扱い性を向上させられると共に、カバーを形成する材料の量を削減してコストダウンも図れる。   As described above, according to the present invention, the cover is formed of a dielectric material having a higher relative dielectric constant than the object, and in the irradiation wave and reflected wave of the ultrashort pulse in the cover due to the wavelength shortening effect accompanying the high relative dielectric constant. By reducing the effective wavelength and reducing the thickness of the cover corresponding to the reduced effective wavelength, the cover surface can be made thin while securing the state where the incident wave and the reflected wave cancel each other. The weight of the cover can be reduced, the handleability can be improved, and the amount of material forming the cover can be reduced to reduce the cost.

また、本発明に係るマイクロ波イメージングシステムは必要に応じて、前記信号解析手段が、前記主反射波信号における表面部からの反射波成分を打消す処理として、前記副反射波信号に、副反射波信号の信号レベルに対する主反射波信号の信号レベルの割合を乗じて、規格化を行ったものを、主反射波信号から差引くものである。   Further, in the microwave imaging system according to the present invention, if necessary, the signal analysis means may perform sub-reflection on the sub-reflection wave signal as a process of canceling the reflection wave component from the surface portion of the main reflection wave signal. The signal obtained by normalization by multiplying the ratio of the signal level of the main reflected wave signal to the signal level of the wave signal is subtracted from the main reflected wave signal.

このように本発明によれば、信号解析手段で、表面での反射波成分を同様に含んだ主反射波信号と副反射波信号の信号レベルを合わせた上で両者の差を得る規格化差分処理を実行し、表面部の反射波成分を打消すようにすることにより、各反射波信号が測定時期の違い等で信号レベルに差が生じており、単純な反射波信号の差引きでは表面部の反射波成分を打消せず、検出対象物の反射波成分を明確化しにくい場合でも、適切に反射波信号を処理して、検出対象物からの反射波成分の存在を明確化でき、反射波信号より得た検出対象物からの反射波成分に基づく画像再構成等処理を正確に実行して、確実に検出対象物の存在に対応した画像を得られる。   As described above, according to the present invention, the signal analysis means combines the signal levels of the main reflected wave signal and the sub reflected wave signal that similarly include the reflected wave component on the surface, and obtains the difference between them. By executing the processing and canceling the reflected wave component of the surface part, each reflected wave signal has a difference in signal level due to the difference in measurement time, etc. Even if it is difficult to clarify the reflected wave component of the object to be detected without canceling the reflected wave component of the part, the reflected wave signal can be processed appropriately to clarify the presence of the reflected wave component from the detected object. It is possible to accurately execute processing such as image reconstruction based on the reflected wave component from the detection target obtained from the wave signal, and to reliably obtain an image corresponding to the presence of the detection target.

また、本発明に係るマイクロ波イメージング処理方法は、周波数成分がマイクロ波帯域に及ぶ超短パルスを、内部に誘電率の異なる検出対象物が存在するか又は存在すると予想される所定の物体に対し複数方向から照射し、複数方向の反射波の測定結果を用いて、合成開口処理を伴う画像再構成を実行し、前記物体内における検出対象物の位置を画像化するマイクロ波イメージング処理方法において、パルス送受信手段が、前記物体表面と略同じ形状に形成された誘電体製のカバーを被せた前記物体に対し、超短パルスを複数方向から同時に又は順次時間をずらして照射すると共に、各照射方向ごとに反射波を受信して、反射波の信号を主反射波信号として出力し、また、前記パルス送受信手段が、前記物体の誘電率に近い誘電率となる材料を用いて形成された前記物体のモデルに、前記カバーを被せたものに対し、超短パルスを複数方向から同時に又は順次時間をずらして照射すると共に、各照射方向ごとに反射波を受信して、反射波の信号を副反射波信号として出力し、信号記録手段が、前記パルス送受信手段から出力される主反射波信号及び／又は副反射波信号を記録し、信号解析手段が、前記信号記録手段から読出される前記主副の反射波信号のいずれか一方と、新たに前記パルス送受信手段から出力されるか、前記信号記録手段から別途読出される、前記主副の各反射波信号の他方とを比較解析し、前記主反射波信号における表面部からの反射波成分を、前記副反射波信号における表面部からの反射波成分で打消し、検出対象物からの反射波成分が相対的に強調された主反射波信号を画像再構成用の新たな反射波信号として出力するものである。   In addition, the microwave imaging processing method according to the present invention applies an ultrashort pulse whose frequency component covers the microwave band to a predetermined object in which a detection target having a different dielectric constant exists or is expected to exist. In the microwave imaging processing method of irradiating from multiple directions, performing image reconstruction with synthetic aperture processing using the measurement results of reflected waves in multiple directions, and imaging the position of the detection target in the object, The pulse transmitting / receiving means irradiates the object covered with a dielectric cover formed in substantially the same shape as the surface of the object with an ultra-short pulse from a plurality of directions simultaneously or sequentially while shifting the time. A material that receives a reflected wave every time and outputs a reflected wave signal as a main reflected wave signal, and the pulse transmitting / receiving means has a dielectric constant close to that of the object. The model of the object formed using the cover is irradiated with an ultrashort pulse from a plurality of directions simultaneously or sequentially while receiving a reflected wave for each irradiation direction, The reflected wave signal is output as a sub reflected wave signal, the signal recording means records the main reflected wave signal and / or the sub reflected wave signal output from the pulse transmitting / receiving means, and the signal analyzing means is the signal recording means. One of the main and sub reflected wave signals read out from the other of the main and sub reflected wave signals newly output from the pulse transmitting / receiving means or read out separately from the signal recording means The reflected wave component from the surface portion in the main reflected wave signal is canceled out by the reflected wave component from the surface portion in the sub reflected wave signal, and the reflected wave component from the detection target is relatively emphasized. Lord And it outputs a reflected wave signal as a new reflected wave signal for image reconstruction.

このように本発明においては、対象物の検出を行おうとする物体にこの物体表面形状を模したカバーを被せた状態で得られた主反射波信号と、物体に近い誘電率の材料を用いて製作された物体モデルに前記同様のカバーを被せた状態で得られた副反射波信号とを信号解析手段で比較し、二つの反射波信号で、カバーを同様に被せられて略同一形状となっている表面部での反射波成分が、同様の信号強度となることを用いて、信号解析手段で主反射波信号における表面部からの反射波成分から副反射波信号における表面部からの反射波成分を差引き、表面での反射波成分を打消す処理を行う。これにより、主反射波信号における検出対象物からの反射波成分にほとんど影響を与えずに、効率よく表面での反射波成分を取除いて、主反射波信号での検出対象物からの反射波成分を相対的に強調できることとなり、物体表面での反射波成分の存在に関わりなく検出対象物からの反射波成分を確実に取得でき、画像再構成で検出対象物の画像化を精度よく実行して、得られた画像からの検出対象物の高精度な検出を可能とする。   As described above, in the present invention, the main reflected wave signal obtained in a state where the object to be detected is covered with a cover simulating the shape of the object surface, and a material having a dielectric constant close to the object is used. The signal reflection means compares the sub-reflected wave signal obtained in the state where the manufactured object model is covered with the same cover as described above, and the cover is covered with the two reflected wave signals in the same manner so as to have substantially the same shape. The reflected wave component at the surface portion has the same signal intensity, and the reflected wave component from the surface portion in the sub reflected wave signal is reflected from the reflected wave component from the surface portion in the main reflected wave signal by the signal analysis means. The component is subtracted and the reflected wave component on the surface is canceled. As a result, the reflected wave component from the detection target in the main reflected wave signal is efficiently removed without affecting the reflected wave component from the detected object in the main reflected wave signal. The component can be relatively emphasized, the reflected wave component from the detection target can be reliably acquired regardless of the presence of the reflected wave component on the object surface, and the imaging of the detection target is accurately performed by image reconstruction. Thus, it is possible to detect the detection object with high accuracy from the obtained image.

また、本発明に係るマイクロ波イメージング処理方法は、周波数成分がマイクロ波帯域に及ぶ超短パルスを、内部に誘電率の異なる検出対象物が存在するか又は存在すると予想される所定の物体に対し複数方向から照射し、複数方向の反射波の測定結果を用いて、合成開口処理を伴う画像再構成を実行し、前記物体内における検出対象物の位置を画像化するマイクロ波イメージング処理方法において、パルス送受信手段が、前記物体に対し、超短パルスを複数方向から同時に又は順次時間をずらして照射すると共に、各照射方向ごとに反射波を受信して、反射波の信号を主反射波信号として出力し、また、前記パルス送受信手段が、前記物体表面と略同じ形状に形成された表面部を有する誘電体製の前記物体のモデルに対し、超短パルスを複数方向から同時に又は順次時間をずらして照射すると共に、各照射方向ごとに反射波を受信して、反射波の信号を副反射波信号として出力し、信号記録手段が、前記パルス送受信手段から出力される主反射波信号及び／又は副反射波信号を記録し、信号解析手段が、前記信号記録手段から読出される前記主副の反射波信号のいずれか一方と、新たに前記パルス送受信手段から出力されるか、前記信号記録手段から別途読出される、前記主副の各反射波信号の他方とを比較解析し、前記主反射波信号における表面部からの反射波成分を、前記副反射波信号における表面部からの反射波成分で打消し、検出対象物からの反射波成分が相対的に強調された主反射波信号を画像再構成用の新たな反射波信号として出力するものである。   In addition, the microwave imaging processing method according to the present invention applies an ultrashort pulse whose frequency component covers the microwave band to a predetermined object in which a detection target having a different dielectric constant exists or is expected to exist. In the microwave imaging processing method of irradiating from multiple directions, performing image reconstruction with synthetic aperture processing using the measurement results of reflected waves in multiple directions, and imaging the position of the detection target in the object, The pulse transmitting / receiving means irradiates the object with an ultrashort pulse from a plurality of directions simultaneously or sequentially, receiving a reflected wave in each irradiation direction, and using the reflected wave signal as a main reflected wave signal. The pulse transmission / reception means outputs an ultrashort pulse to a model of the object made of a dielectric having a surface portion formed in substantially the same shape as the object surface. Irradiation is performed simultaneously or sequentially from the direction, and the reflected wave is received for each irradiation direction, and the reflected wave signal is output as a sub-reflected wave signal, and the signal recording means is output from the pulse transmitting / receiving means. The main reflected wave signal and / or the sub reflected wave signal are recorded, and the signal analysis means outputs a new one from the main / sub reflected wave signal read from the signal recording means and the pulse transmitting / receiving means. Or the other of the main and sub reflected wave signals read separately from the signal recording means, and the reflected wave component from the surface portion of the main reflected wave signal is converted into the sub reflected wave signal. The main reflected wave signal in which the reflected wave component from the detection target is canceled and the reflected wave component from the detection target is relatively emphasized is output as a new reflected wave signal for image reconstruction.

このように本発明においては、対象物の検出を行おうとする物体について取得した主反射波信号と、物体の表面形状に略一致する表面形状を有する物体モデルについて取得した副反射波信号とを信号解析手段で比較し、二つの反射波信号で、同様の形状である表面部での反射波成分が、同様の信号強度となることを用いて、信号解析手段で主反射波信号における物体表面からの反射波成分から副反射波信号におけるモデル表面からの反射波成分を差引き、表面での反射波成分を打消す処理を行う。これにより、主反射波信号における検出対象物からの反射波成分にほとんど影響を与えずに、効率よく表面での反射波成分を取除いて、主反射波信号での検出対象物からの反射波成分を相対的に強調できることとなり、物体表面での反射波成分の存在に関わりなく検出対象物からの反射波成分を確実に取得でき、画像再構成で検出対象物の画像化を精度よく実行して、得られた画像からの検出対象物の高精度な検出を可能とする。   As described above, in the present invention, the main reflected wave signal acquired for the object to be detected and the sub-reflected wave signal acquired for the object model having a surface shape that substantially matches the surface shape of the object are signaled. Compared with the analysis means, the reflected wave component at the surface portion having the same shape with the two reflected wave signals has the same signal intensity, and the signal analysis means from the object surface in the main reflected wave signal. The reflected wave component from the model surface in the sub-reflected wave signal is subtracted from the reflected wave component to cancel the reflected wave component on the surface. As a result, the reflected wave component from the detection target in the main reflected wave signal is efficiently removed without affecting the reflected wave component from the detected object in the main reflected wave signal. The component can be relatively emphasized, the reflected wave component from the detection target can be reliably acquired regardless of the presence of the reflected wave component on the object surface, and the imaging of the detection target is accurately performed by image reconstruction. Thus, it is possible to detect the detection object with high accuracy from the obtained image.

本発明の第１の実施形態に係るマイクロ波イメージングシステムのブロック構成図である。1 is a block configuration diagram of a microwave imaging system according to a first embodiment of the present invention. 本発明の第１の実施形態に係るマイクロ波イメージングシステムにおけるアンテナ移動機構の説明図である。It is explanatory drawing of the antenna moving mechanism in the microwave imaging system which concerns on the 1st Embodiment of this invention. 本発明の第１の実施形態に係るマイクロ波イメージングシステムにおける測定対象の物体及びモデルへのカバー被覆状態説明図である。It is explanatory drawing of the cover covering state to the measurement object and model in the microwave imaging system according to the first embodiment of the present invention. 本発明の第１の実施形態に係るマイクロ波イメージングシステムにおける主副各反射波信号を用いた打消し処理の概念説明図である。It is a conceptual explanatory view of the cancellation process using the main and sub reflected wave signals in the microwave imaging system according to the first embodiment of the present invention. 本発明の第１の実施形態に係るマイクロ波イメージングシステムにおけるパルス送受信手段で得た所定測定方向での主反射波信号の波形のグラフである。It is a graph of the waveform of the main reflected wave signal in the predetermined measurement direction obtained by the pulse transmission / reception means in the microwave imaging system according to the first embodiment of the present invention. 本発明の第１の実施形態に係るマイクロ波イメージングシステムにおけるパルス送受信手段で得た所定測定方向での副反射波信号の波形のグラフである。It is a graph of the waveform of the sub reflected wave signal in the predetermined measurement direction obtained with the pulse transmission / reception means in the microwave imaging system which concerns on the 1st Embodiment of this invention. 本発明の第１の実施形態に係るマイクロ波イメージングシステムにおける信号解析手段による打消し処理で得られた所定測定方向での反射波信号の波形のグラフである。It is a graph of the waveform of the reflected wave signal in the predetermined measurement direction obtained by the cancellation process by the signal analysis means in the microwave imaging system according to the first embodiment of the present invention. 本発明の第１の実施形態に係るマイクロ波イメージングシステムにおける信号解析手段による打消し処理で得られたカバー使用時についての全測定方向での反射波信号の時間変化をあらわす信号強度図及びその要部拡大図である。FIG. 2 is a signal intensity diagram showing a time change of a reflected wave signal in all measurement directions when the cover is used, obtained by cancellation processing by the signal analysis unit in the microwave imaging system according to the first embodiment of the present invention, and its essentials. FIG. 本発明の第１の実施形態に係るマイクロ波イメージングシステムにおける信号解析手段による打消し処理で得られたカバー不使用時についての全測定方向での反射波信号の時間変化をあらわす信号強度図及びその要部拡大図である。FIG. 4 is a signal intensity diagram showing a time change of a reflected wave signal in all measurement directions when the cover is not used, obtained by cancellation processing by the signal analysis unit in the microwave imaging system according to the first embodiment of the present invention, and It is a principal part enlarged view. 本発明の第２の実施形態に係るマイクロ波イメージングシステムにおける主副各反射波信号を用いた打消し処理の概念説明図である。It is a conceptual explanatory drawing of the cancellation process using the main / sub each reflected wave signal in the microwave imaging system which concerns on the 2nd Embodiment of this invention. 本発明の第２の実施形態に係るマイクロ波イメージングシステムで得られる全測定方向での主反射波信号及び石膏モデルについての副反射波信号の各時間変化をあらわす信号強度図である。It is a signal strength figure showing each time change of the main reflected wave signal in all the measurement directions obtained with the microwave imaging system concerning a 2nd embodiment of the present invention, and the sub reflected wave signal about a plaster model. 本発明の第２の実施形態に係るマイクロ波イメージングシステムにおける石膏モデル使用時の信号解析手段による打消し処理で得られた全測定方向での反射波信号の時間変化をあらわす信号強度図である。It is a signal strength figure showing the time change of the reflected wave signal in all the measurement directions obtained by the cancellation processing by the signal analysis means at the time of use of the gypsum model in the microwave imaging system concerning a 2nd embodiment of the present invention. 本発明の第２の実施形態に係るマイクロ波イメージングシステムで得られる全測定方向での主反射波信号及び寒天モデルについての副反射波信号の各時間変化をあらわす信号強度図である。It is a signal strength diagram showing each time change of the main reflected wave signal in all the measurement directions obtained with the microwave imaging system concerning a 2nd embodiment of the present invention, and the sub reflected wave signal about an agar model. 本発明の第２の実施形態に係るマイクロ波イメージングシステムにおける寒天モデル使用時の信号解析手段による打消し処理で得られた全測定方向での反射波信号の時間変化をあらわす信号強度図である。It is a signal strength diagram showing the time change of the reflected wave signal in all the measurement directions obtained by the cancellation process by the signal analysis means at the time of using the agar model in the microwave imaging system according to the second embodiment of the present invention. 本発明の第２の実施形態に係るマイクロ波イメージングシステムにおける同形状ファントム使用時の信号解析手段による打消し処理で得られた全測定方向での反射波信号の時間変化をあらわす信号強度図及びその要部拡大図である。FIG. 7 is a signal intensity diagram showing a time change of a reflected wave signal in all measurement directions obtained by cancellation processing by the signal analysis means when using the same shape phantom in the microwave imaging system according to the second embodiment of the present invention, and FIG. It is a principal part enlarged view. 本発明の第２の実施形態に係るマイクロ波イメージングシステムにおける異形状ファントム使用時の信号解析手段による打消し処理で得られた全測定方向での反射波信号の時間変化をあらわす信号強度図及びその要部拡大図である。FIG. 7 is a signal intensity diagram showing a time change of the reflected wave signal in all measurement directions obtained by cancellation processing by the signal analysis means when using the deformed phantom in the microwave imaging system according to the second embodiment of the present invention; It is a principal part enlarged view. 本発明の他の実施形態に係るマイクロ波イメージングシステムのブロック構成図である。It is a block block diagram of the microwave imaging system which concerns on other embodiment of this invention. 本発明のマイクロ波イメージングシステムにおけるパルス発生器で生じたパルス出力波形、及び照射アンテナからの実際の出力波形の各グラフである。It is each graph of the pulse output waveform produced | generated with the pulse generator in the microwave imaging system of this invention, and the actual output waveform from an irradiation antenna. 本発明のマイクロ波イメージングシステムにおける画像再構成手段で実施例１の第一例に係る反射波信号について画像再構成を行って得られた画像の説明図である。It is explanatory drawing of the image obtained by performing image reconstruction about the reflected wave signal which concerns on the 1st example of Example 1 with the image reconstruction means in the microwave imaging system of this invention. 本発明のマイクロ波イメージングシステムにおける画像再構成手段で実施例１の第二例に係る反射波信号について画像再構成を行って得られた画像の説明図である。It is explanatory drawing of the image obtained by performing image reconstruction about the reflected wave signal which concerns on the 2nd example of Example 1 by the image reconstruction means in the microwave imaging system of this invention. 本発明のマイクロ波イメージングシステムにおける画像再構成手段で実施例１の第三例に係る反射波信号について画像再構成を行って得られた画像の説明図である。It is explanatory drawing of the image obtained by performing image reconstruction about the reflected wave signal which concerns on the 3rd example of Example 1 by the image reconstruction means in the microwave imaging system of this invention. 本発明のマイクロ波イメージングシステムにおける信号解析手段による打消し処理で得られた実施例２の第一例に係る全測定方向での反射波信号の時間変化をあらわす信号強度図である。It is a signal intensity figure showing the time change of the reflected wave signal in all the measurement directions concerning the 1st example of Example 2 obtained by cancellation processing by the signal analysis means in the microwave imaging system of the present invention. 本発明のマイクロ波イメージングシステムにおける信号解析手段による打消し処理で得られた実施例２の第二例に係る全測定方向での反射波信号の時間変化をあらわす信号強度図である。It is a signal strength figure showing the time change of the reflected wave signal in all the measurement directions concerning the 2nd example of Example 2 obtained by cancellation processing by the signal analysis means in the microwave imaging system of the present invention. 本発明のマイクロ波イメージングシステムにおける信号解析手段による打消し処理で得られた実施例２の第三例に係る全測定方向での反射波信号の時間変化をあらわす信号強度図である。It is a signal intensity figure showing the time change of the reflected wave signal in all the measurement directions concerning the 3rd example of Example 2 obtained by cancellation processing by the signal analysis means in the microwave imaging system of the present invention. 本発明のマイクロ波イメージングシステムにおける信号解析手段による打消し処理で得られた実施例２の第四例に係る全測定方向での反射波信号の時間変化をあらわす信号強度図である。It is a signal intensity figure showing the time change of the reflected wave signal in all the measurement directions concerning the 4th example of Example 2 obtained by cancellation processing by the signal analysis means in the microwave imaging system of the present invention.

（本発明の第１の実施形態）
以下、本発明の第１の実施形態に係るマイクロ波イメージングシステムを前記図１ないし図９に基づいて説明する。本実施形態においては、検出対象物としての腫瘍が物体としての人体胸部組織の内部に存在するか否かを、物体とそのモデルとを用い、これらからの反射波を解析して得た画像から検出可能とする乳がん検出用のシステムの例について説明する。 (First embodiment of the present invention)
Hereinafter, a microwave imaging system according to a first embodiment of the present invention will be described with reference to FIGS. In this embodiment, whether or not a tumor as a detection target exists inside the human breast tissue as an object is determined based on an image obtained by analyzing the reflected wave from the object and its model. An example of a breast cancer detection system that can be detected will be described.

前記各図において本実施形態に係るマイクロ波イメージングシステム１は、マイクロ波帯域の超短パルスを、内部に検出対象物６０が存在すると予想される物体５０に対し複数方向から照射すると共に、物体５０表面部や検出対象物６０等からの反射波を受信し、反射波の信号を出力するパルス送受信手段１１と、各測定方向ごとに得られる反射波信号を記録する信号記録手段１２と、信号記録手段１２から読出した一の反射波信号と、新たにパルス送受信手段１１から出力される他の反射波信号とを比較解析し、物体５０表面部からの反射波成分が打消された反射波の新たな信号を得る信号解析手段１３と、この信号解析手段１３で得られた各測定方向ごとの信号から画像再構成を行って物体内表示画像を得る画像再構成手段１５と、得られた物体内表示画像を表示する表示手段１６とを備える構成である。   In each of the drawings, the microwave imaging system 1 according to the present embodiment irradiates an object 50 in which a detection target 60 is expected to be present from a plurality of directions with an ultrashort pulse in the microwave band. A pulse transmission / reception unit 11 that receives a reflected wave from the surface portion, the detection object 60, and the like and outputs a reflected wave signal, a signal recording unit 12 that records a reflected wave signal obtained for each measurement direction, and a signal recording One reflected wave signal read out from the means 12 and another reflected wave signal newly output from the pulse transmitting / receiving means 11 are compared and analyzed, and a new reflected wave from which the reflected wave component from the surface of the object 50 is canceled is analyzed. A signal analyzing unit 13 for obtaining a simple signal, an image reconstructing unit 15 for performing image reconstruction from a signal for each measurement direction obtained by the signal analyzing unit 13 to obtain an in-object display image, and And a structure and a display unit 16 for displaying an object in the displayed image.

なお、いったん信号記録手段１２に記録されてから読出される前記一の反射波信号は、前記物体（人体胸部組織）５０の誘電率に近い誘電率となる材料を用いて形成された物体のモデル７０に、物体表面と略同じ形状に形成された誘電体製のカバー８０を被せたものについて、前記パルス送受信手段１１で各方向ごとに所定時間にわたり超短パルスを照射し且つ反射波を受信することで得られる反射波信号である。   The one reflected wave signal that is once recorded after being recorded in the signal recording means 12 is an object model formed using a material having a dielectric constant close to that of the object (human breast tissue) 50. 70 covered with a dielectric cover 80 formed in substantially the same shape as the surface of the object, the pulse transmitting / receiving means 11 irradiates an ultrashort pulse in each direction for a predetermined time and receives a reflected wave. It is a reflected wave signal obtained by this.

また、新たにパルス送受信手段１１から出力される前記他の反射波信号は、前記同様のカバー８０を被せた物体５０について、パルス送受信手段１１で各方向ごとに所定時間にわたり超短パルスを照射し且つ反射波を受信することで得られる反射波信号である。この他の反射波信号を、物体５０に対応する点から主反射波信号とし、前記一の反射波信号を副反射波信号とする。   Further, the other reflected wave signal newly output from the pulse transmitting / receiving means 11 irradiates the object 50 covered with the same cover 80 with an ultrashort pulse for a predetermined time in each direction by the pulse transmitting / receiving means 11. And it is a reflected wave signal obtained by receiving the reflected wave. The other reflected wave signal is a main reflected wave signal from the point corresponding to the object 50, and the one reflected wave signal is a sub reflected wave signal.

前記パルス送受信手段１１は、検出対象物６０（例えば、乳がんをなす腫瘍）が存在するか、存在すると予想される物体５０（例えば、胸部組織）に対し、その表面を覆うカバー８０を介して、パルス幅が１〜１００ｐｓとなる超短パルスを照射し、且つ物体５０や検出対象物６０等からの反射波を受信する一連の測定動作を実行して、反射波の信号を出力するものである。   The pulse transmission / reception means 11 has a detection target 60 (for example, a tumor that forms breast cancer), or an object 50 (for example, breast tissue) that is expected to exist, via a cover 80 that covers the surface thereof. A series of measurement operations for irradiating an ultrashort pulse with a pulse width of 1 to 100 ps and receiving a reflected wave from the object 50, the detection target 60, etc. is executed, and a reflected wave signal is output. .

詳細には、パルス送受信手段１１は、図１に示すように、カバー８０を表面に配設した測定対象の物体５０に超短パルスを照射する照射アンテナ１１ａと、この照射アンテナ１１ａ近傍に配設されて物体５０や検出対象物６０等からの反射波を受信する受信アンテナ１１ｂと、超短パルスを発生させるパルス発生器１１ｃと、照射アンテナ１１ａと受信アンテナ１１ｂの組を物体５０の周囲で移動させて超短パルスの照射方向を変化させるアンテナ移動機構１１ｄと、受信アンテナ１１ｂからの反射波が入力され、外部へ解析可能な状態の反射波信号として出力する信号入出力部１１ｅと、パルス照射のタイミングに合わせてアンテナ移動機構１１ｄを制御する制御部１１ｆとを備える構成である。   Specifically, as shown in FIG. 1, the pulse transmitting / receiving means 11 is provided with an irradiation antenna 11a for irradiating an object 50 to be measured with a cover 80 disposed on the surface thereof, and in the vicinity of the irradiation antenna 11a. The receiving antenna 11b that receives the reflected wave from the object 50, the detection target 60, etc., the pulse generator 11c that generates an ultrashort pulse, and the irradiation antenna 11a and the receiving antenna 11b are moved around the object 50. An antenna moving mechanism 11d that changes the irradiation direction of the ultrashort pulse, a signal input / output unit 11e that receives a reflected wave from the receiving antenna 11b and outputs it as a reflected wave signal that can be analyzed to the outside, and pulse irradiation And a control unit 11f that controls the antenna moving mechanism 11d in accordance with the timing.

このパルス送受信手段１１では、パルス発生器１１ｃから出力される超短パルスが、照射アンテナ１１ａから照射波としてカバー８０越しに物体５０に照射される。そして、物体５０表面部、すなわちカバー８０表裏面と物体５０表面、や内部の検出対象物６０で反射された反射波の信号を受信アンテナ１１ｂで受信し、得られた反射波の信号が信号解析手段１３に入力される。   In this pulse transmission / reception means 11, the ultrashort pulse output from the pulse generator 11c is irradiated to the object 50 through the cover 80 as an irradiation wave from the irradiation antenna 11a. Then, the reception antenna 11b receives the reflected wave signal reflected by the surface of the object 50, that is, the front and back surfaces of the cover 80 and the surface of the object 50, and the detection object 60 inside, and the obtained reflected wave signal is subjected to signal analysis. Input to means 13.

照射される超短パルスの波形は、ピコ秒のパルス幅を持つインパルスであり、例えば、パルス幅１０〜１００ｐｓで、そのフーリエ変換後の周波数成分がマイクロ波帯域で約１〜１２ＧＨｚの超広帯域（ＵＷＢ）となるものである。照射アンテナ１１ａや受信アンテナ１１ｂとしては、こうした超広帯域に対応した、すなわち周波数による特性変化が小さく、照射及び受信波形がパルス発生器でのパルス波形になるべく近くなるような分散特性が小さいものを用いるのがより好ましい。このような特性を有するアンテナとして、ボウタイアンテナ、ログスパイラルアンテナ、ビバルディアンテナ等を用いる。   The waveform of the ultrashort pulse to be irradiated is an impulse having a pulse width of picoseconds. For example, the pulse width is 10 to 100 ps, and the frequency component after the Fourier transform is an ultra wideband of about 1 to 12 GHz in the microwave band ( UWB). As the irradiation antenna 11a and the receiving antenna 11b, those corresponding to such an ultra-wide band, that is, having a small dispersion characteristic such that the characteristic change due to the frequency is small and the irradiation and reception waveforms are as close as possible to the pulse waveform of the pulse generator are used. Is more preferable. As an antenna having such characteristics, a bow tie antenna, a log spiral antenna, a Vivaldi antenna, or the like is used.

超短パルスを物体５０に照射すると、誘電率が大きく変化する部位、すなわち、誘電率の異なる二つの物質の境界である物体５０の表面部、詳細にはカバー８０表裏面や物体表面で、また、検出対象物６０の表面部分で、反射した反射波が得られる。受信アンテナ１１ｂで受信した反射波には、こうした物体５０表面部での反射波成分や検出対象物６０からの反射波成分が含まれており、このうち、検出対象物６０からの反射波成分の照射時からの遅れ時間、すなわちパルスの飛行時間を算出することで、反射面、すなわち検出対象物６０の表面位置を求めることができる。さらに、アンテナ移動機構１１ｄにより各アンテナ位置を動かして、物体５０への超短パルスの照射方向を変えて繰返し測定した同様の結果から、合成開口処理により画像再構成を実行すれば、物体５０中の検出対象物６０の位置を特定できる画像情報が得られることとなる。反射面位置を求める原理自体は、照射時から反射波到来までの遅れ時間により決定するいわゆるレーダと同じ原理である。   When the object 50 is irradiated with an ultrashort pulse, the part where the dielectric constant changes greatly, that is, the surface part of the object 50 that is the boundary between two substances having different dielectric constants, specifically, the front and back surfaces of the cover 80 or the object surface, The reflected wave reflected by the surface portion of the detection object 60 is obtained. The reflected wave received by the receiving antenna 11b includes such a reflected wave component on the surface of the object 50 and a reflected wave component from the detection target 60. Of these, the reflected wave component from the detection target 60 By calculating the delay time from the time of irradiation, that is, the flight time of the pulse, the position of the reflection surface, that is, the surface of the detection target 60 can be obtained. Furthermore, if image reconstruction is executed by synthetic aperture processing based on the same results obtained by repeatedly measuring each antenna position by moving the antenna position by the antenna moving mechanism 11d and changing the irradiation direction of the ultrashort pulse on the object 50, The image information that can specify the position of the detection object 60 is obtained. The principle of obtaining the position of the reflecting surface itself is the same principle as a so-called radar that is determined by the delay time from the time of irradiation until the arrival of the reflected wave.

前記アンテナ移動機構１１ｄは、物体５０を取囲む所定の測定経路上で、物体５０を中心とした所定角度分だけ、照射アンテナ１１ａ及び受信アンテナ１１ｂを移動させるものである（図２参照）。このアンテナ移動機構１１ｄは、照射アンテナ１１ａ及び受信アンテナ１１ｂを所定角度に位置させ、この角度における一回の測定過程が終了したら、制御部１１ｆによる制御を受けて、アンテナ位置を次の角度まで動かし、これを繰返して各方向からの測定を実行可能とする。   The antenna moving mechanism 11d moves the irradiation antenna 11a and the receiving antenna 11b by a predetermined angle about the object 50 on a predetermined measurement path surrounding the object 50 (see FIG. 2). The antenna moving mechanism 11d positions the irradiation antenna 11a and the receiving antenna 11b at a predetermined angle, and when a measurement process at this angle is completed, the antenna moving mechanism 11d is controlled by the control unit 11f to move the antenna position to the next angle. This is repeated to enable measurement from each direction.

一回の測定過程は、所定回の繰返しパルス照射と各パルスに対応する物体５０内の検出対象物６０からの反射波を得、これらを信号入出力部１１ｅで積分し、信号対雑音（Ｓ／Ｎ）比を向上させた反射波信号を取得する手順で行われる。例えば、信号入出力部１１ｅに高速ディジタイジングスコープ（サンプリングスコープ）を使用し、パルスの繰返し周波数を１ＭＨｚ（１マイクロ秒間隔）とすると、サンプリング方式で２０００点の１トレースを得るには、１マイクロ秒×２０００＝２ミリ秒の測定時間がかかる。この信号入出力部１１ｅで測定精度を向上させるために１６回のトレースの積分を行う場合、一回の測定過程に費やす時間は、２ミリ秒×１６＝３２ミリ秒となる。   In one measurement process, a predetermined number of repeated pulse irradiations and a reflected wave from the detection target 60 in the object 50 corresponding to each pulse are obtained, integrated by the signal input / output unit 11e, and signal-to-noise (S / N) The procedure is to obtain a reflected wave signal with an improved ratio. For example, if a high-speed digitizing scope (sampling scope) is used for the signal input / output unit 11e and the pulse repetition frequency is 1 MHz (1 microsecond interval), 1 micron is required to obtain 2000 traces by the sampling method. It takes a measurement time of seconds × 2000 = 2 milliseconds. When the integration of 16 traces is performed in this signal input / output unit 11e in order to improve the measurement accuracy, the time spent for one measurement process is 2 milliseconds × 16 = 32 milliseconds.

このアンテナ移動機構１１ｄで、各アンテナを物体５０を中心とした物体５０上の１８０°の角度範囲にわたって所定角度ずつずらしながら、各角度位置での測定方向について反射波信号を得ていくことで、画像再構成手段１５が合成開口処理を伴う画像再構成により物体内部の二次元画像（図１９〜図２１参照）を得られる仕組みであるが、さらにアンテナ移動機構を用いて、横方向における物体５０周りに各アンテナを１８０°の角度範囲にわたって所定角度ごとに上記の一連の測定を繰返し行うようにして、物体内の全ての領域の情報を得て、最終的に三次元の画像を得るようにすることもできる。   With this antenna moving mechanism 11d, each antenna is shifted by a predetermined angle over an angular range of 180 ° on the object 50 with the object 50 as the center, and a reflected wave signal is obtained in the measurement direction at each angular position, The image reconstruction means 15 is a mechanism that can obtain a two-dimensional image (see FIGS. 19 to 21) inside the object by image reconstruction accompanied by a synthetic aperture process. Further, the object 50 in the lateral direction can be obtained using an antenna moving mechanism. By repeating the above series of measurements at predetermined angles over an angular range of 180 ° around each antenna, information on all regions in the object is obtained, and finally a three-dimensional image is obtained. You can also

パルス送受信手段１１は、物体５０の場合と同様、カバー８０を被せたモデル７０に対しても、超短パルスを照射する一方、モデル７０の表面部、すなわち、カバー８０表裏面やモデル表面からの反射波を受信して、反射波の信号を出力可能である。こうしたモデル７０が測定対象となる場合、パルス送受信手段１１は、得られた反射波の信号を信号記録手段１２に出力し、信号記録手段１２でこの反射波信号を記録することとなる。   As in the case of the object 50, the pulse transmission / reception means 11 irradiates the model 70 covered with the cover 80 with an ultrashort pulse, while the surface portion of the model 70, that is, from the front and back surfaces of the cover 80 and the model surface. A reflected wave signal can be received and a reflected wave signal can be output. When such a model 70 is a measurement object, the pulse transmitting / receiving unit 11 outputs the obtained reflected wave signal to the signal recording unit 12 and the signal recording unit 12 records the reflected wave signal.

前記信号記録手段１２は、パルス送受信手段１１でのパルス照射及び反射波の受信が、カバー８０を被せた物体５０やモデル７０に対するパルス送受信手段１１の各アンテナ角度位置を切換えつつ、各角度ごとに時間を変えて実行されるため、パルス送受信手段１１から全ての測定方向の反射波信号が得られるまで、各測定方向ごとの反射波信号をデータとして記録し、この反射波信号のデータを、所望時点で信号解析手段１３に提供するなど、まとめて取扱い可能とするものである。   The signal recording unit 12 is configured to switch the antenna angular position of the pulse transmitting / receiving unit 11 with respect to the object 50 or the model 70 covered with the cover 80 for each angle while receiving the pulse irradiation and the reflected wave by the pulse transmitting / receiving unit 11. Since it is executed at different times, the reflected wave signal for each measurement direction is recorded as data until the reflected wave signals in all the measurement directions are obtained from the pulse transmission / reception means 11, and the data of this reflected wave signal is recorded as desired. For example, it can be handled collectively by providing it to the signal analysis means 13.

信号記録手段１２が、パルス送受信手段１１で得られる各測定方向ごとの反射波信号をデータとして記録し、必要に応じ読出せるようにしていることで、この記録された一の反射波信号と、後で別途得られる他の反射波信号との比較解析を信号解析手段１３において行えることとなる。   The signal recording means 12 records the reflected wave signal for each measurement direction obtained by the pulse transmission / reception means 11 as data, and can read it as necessary. Comparison analysis with other reflected wave signals obtained separately later can be performed in the signal analysis means 13.

また、信号記録手段１２は、パルス送受信手段１１からの出力分とは別に、信号解析手段１３から出力される各測定方向ごとの新たな反射波信号もデータとして記録して、この反射波信号のデータをまとめて画像再構成手段１５に提供できるようにしている。
こうした信号記録手段１２の構成自体は、電子データを外部に取り出し可能に保持する公知の記録装置と同様のものであり、説明を省略する。 In addition to the output from the pulse transmission / reception means 11, the signal recording means 12 records a new reflected wave signal for each measurement direction output from the signal analysis means 13 as data, and the reflected wave signal The data can be collectively provided to the image reconstruction means 15.
The configuration of the signal recording unit 12 is the same as that of a known recording apparatus that holds electronic data so that it can be taken out to the outside, and the description thereof is omitted.

前記信号解析手段１３は、信号記録手段１２から読出される一の反射波信号と、新たにパルス送受信手段１１から出力される他の反射波信号とを比較解析するものである。   The signal analyzing means 13 compares and analyzes one reflected wave signal read from the signal recording means 12 and another reflected wave signal newly output from the pulse transmitting / receiving means 11.

詳細には、信号解析手段１３は、前記一の反射波信号である、カバー８０を被せたモデル７０について得られた副反射波信号を信号記録手段１２から読出す一方、前記他の反射波信号である、カバー８０を被せた物体５０についてパルス送受信手段１１で得られる主反射波信号の入力を受け、主反射波信号における表面部からの反射波成分を、副反射波信号における表面部からの反射波成分で打消し、検出対象物６０からの反射波成分が相対的に強調された主反射波信号を画像再構成用の新たな反射波信号として、信号記録手段１２を介して画像再構成手段１５に送出すものである。   Specifically, the signal analysis means 13 reads out the sub reflected wave signal obtained for the model 70 covered with the cover 80, which is the one reflected wave signal, from the signal recording means 12, while the other reflected wave signal. The main reflected wave signal obtained by the pulse transmitting / receiving means 11 is received with respect to the object 50 covered with the cover 80, and the reflected wave component from the surface portion in the main reflected wave signal is changed from the surface portion in the sub reflected wave signal. Image reconstruction is performed via the signal recording means 12 as a new reflected wave signal for image reconstruction, with the main reflected wave signal canceled by the reflected wave component and the reflected wave component from the detection target 60 is relatively emphasized. This is sent to the means 15.

なお、信号解析手段１３で取扱う他の反射波信号は、前記一の反射波信号が信号記録手段１２に記録された後、新たにパルス送受信手段１１から測定方向ごとに出力されて信号解析手段１３に入力されるものに限られず、一の反射波信号と同様の手順で信号記録手段１２の別の記録領域又は別の信号記録手段に記録され、信号解析手段１３により一の反射波信号と共に読出されるものであってもよい。すなわち、測定による反射波信号出力と解析を必ずしも同時に進めなくてもかまわず、二つの反射波信号の取得を先行して行い、後で反射波信号の解析のみ行うことができる。   The other reflected wave signals handled by the signal analyzing means 13 are newly output from the pulse transmitting / receiving means 11 for each measurement direction after the one reflected wave signal is recorded in the signal recording means 12, and the signal analyzing means 13 Is recorded in another recording area of the signal recording means 12 or another signal recording means in the same procedure as that of one reflected wave signal, and is read together with one reflected wave signal by the signal analyzing means 13. It may be done. That is, the reflected wave signal output by the measurement and the analysis do not necessarily have to proceed at the same time, two reflected wave signals can be acquired in advance, and only the reflected wave signal can be analyzed later.

この信号解析手段１３での、前記主反射波信号における表面部からの反射波成分を打消せる仕組みについてより詳細に説明する。
パルス送受信手段１１で超短パルスを照射する複数の物質について、それらの材質が異なっていても、互いの比誘電率が近く、パルスの照射波が反射する物質表面の形状が互いに似ている場合、反射波信号のうち、各物質の表面からの反射波成分は同程度の信号レベルとなる性質がある。 A mechanism for canceling the reflected wave component from the surface portion in the main reflected wave signal in the signal analyzing means 13 will be described in more detail.
When a plurality of materials irradiated with ultrashort pulses by the pulse transmitting / receiving means 11 are different from each other, their relative dielectric constants are close to each other, and the shapes of the material surfaces on which the pulse irradiation waves are reflected are similar to each other Of the reflected wave signal, the reflected wave component from the surface of each substance has the property of having the same signal level.

よって、この性質を利用して、物体内部の検出対象物からの反射波成分が減衰により大きく低下する状況下において、事前に物体と表面形状は同じであるものの材質の異なるモデルについて、表面の反射波成分を含む反射波信号を取得しておき、リファレンス信号として活用する。すなわち、実際の対象物検出を行おうとする物体についての反射波信号を取得する際に、この反射波信号に含まれる表面からの反射波成分を、先のモデルについての反射波信号における表面からの反射波成分で打消すことで、マスキングされていた検出対象物からの反射波成分を確実に取得できることとなる（図４参照）。   Therefore, using this property, in a situation where the reflected wave component from the object to be detected inside the object is greatly reduced by attenuation, the surface reflection of a model with the same material and surface shape but different materials in advance. A reflected wave signal including a wave component is acquired and used as a reference signal. That is, when acquiring a reflected wave signal for an object to be actually detected, the reflected wave component from the surface included in the reflected wave signal is converted from the surface in the reflected wave signal for the previous model. By canceling with the reflected wave component, the reflected wave component from the detection target that has been masked can be reliably acquired (see FIG. 4).

具体的には、対象物検出を行おうとする物体５０と、この物体５０とは材質の異なるモデル７０に対し、同様に表面に被せるカバー８０を使用することにより、表面形状の一致を図り、信号解析手段１３で表面部からの反射波成分を打消せるようにしている。   Specifically, the object 50 to be detected and the model 70 made of a material different from that of the object 50 are similarly covered by using a cover 80 that covers the surface, thereby matching the surface shape and the signal. The analysis means 13 can cancel the reflected wave component from the surface portion.

モデル７０については、パルス送受信手段１１で得られる反射波信号を物体５０の場合とより近いものとするため、その誘電率は、物体５０としての胸部の誘電率、より具体的には、胸部主要組織（***脂肪）の誘電率と近い値、すなわち、約５〜２０とするのが好ましい。形状についても、カバー８０との密着性を考慮して、物体５０の形状に近いものとするのが好ましい。   For the model 70, the reflected wave signal obtained by the pulse transmission / reception means 11 is closer to that of the object 50, so that the dielectric constant is the dielectric constant of the chest as the object 50, more specifically, the chest main A value close to the dielectric constant of the tissue (breast fat), that is, about 5 to 20 is preferable. The shape is preferably close to the shape of the object 50 in consideration of the adhesion with the cover 80.

このモデル７０としては、乳がん検出の場合、人体の胸部を模して作成された胸部ファントムを利用できるが、これ以外にも、プラスチック、石膏、寒天や油を用いたものでも同様の効果が可能となり、これらの材料を使用した場合、モデルの製作が容易且つ低コストで行える。   As this model 70, in the case of breast cancer detection, a chest phantom created by imitating the chest of a human body can be used, but other than this, the same effect can be obtained using plastic, gypsum, agar or oil. When these materials are used, the model can be easily manufactured at low cost.

前記カバー８０は、本実施形態の人体胸部組織である物体５０に対し、人体の統計的な胸部の形状や大きさに合わせて製作されて、物体５０やモデル７０の表面に配設されるものである。人の胸部の様々な形状や大きさに対し、コスト面等で実現可能な範囲で対応できるよう、複数通りの大きさのカバー８０があらかじめ用意され、実際の測定時に適切な大きさのカバー８０を選択して使用することとなる。もちろん、カバー８０を測定時の物体５０の表面形状に完全に合わせた形状として形成するのが、カバーと物体との完全な密着を得やすく、表面部での反射波成分除去の効果の点のみ考慮すれば最も好ましい。   The cover 80 is manufactured according to the statistical chest shape and size of the human body relative to the object 50 which is the human chest tissue of the present embodiment, and is disposed on the surface of the object 50 or the model 70. It is. A plurality of sizes of covers 80 are prepared in advance so that various shapes and sizes of a person's chest can be realized within a range that can be realized in terms of cost and the like. Will be used. Of course, forming the cover 80 as a shape that perfectly matches the surface shape of the object 50 at the time of measurement makes it easy to obtain complete adhesion between the cover and the object, and only the effect of removing the reflected wave component from the surface portion. It is most preferable if it is considered.

カバー８０の形状としては、物体５０やモデル７０の表面に沿う形状の本体部分の他に、この本体部分の周囲に物体５０やモデル７０のある領域より外側に張出す部分を設けるようにして、この張出し部分８０ａを物体５０やモデル７０を支持する台等に対し固定状態とするのが好ましい（図３参照）。また、カバー８０の位置を固定する場合には、前記張出し部分を押え板１７等を併用して本体部分の周囲全周にわたって固定して、物体５０やモデル７０の表面に沿って反射波に影響を与えるカバー本体部分に、歪みが生じるのを抑えるようにするのが好ましい。   As the shape of the cover 80, in addition to the main body portion shaped along the surface of the object 50 or the model 70, a portion that protrudes outside the region where the object 50 or the model 70 exists is provided around the main body portion. The overhanging portion 80a is preferably fixed with respect to the object 50, a stand for supporting the model 70, and the like (see FIG. 3). Further, when the position of the cover 80 is fixed, the overhanging portion is fixed along the entire circumference of the main body portion together with the holding plate 17 or the like, and the reflected wave is affected along the surface of the object 50 or the model 70. It is preferable to suppress the occurrence of distortion in the cover main body portion that provides the above.

このカバー８０は、誘電体で形成されるが、信号解析手段１３でこのカバー表面の反射波成分を打消す処理が行われるため、その比誘電率は物体とカバーの周囲媒体（通常は空気）との間の値であれば、特に限定されない。すなわち、カバーとする誘電体材料の比誘電率が小さい、例えば比誘電率が２に近い場合、屈折率が１に近く、空気との屈折率の差が小さくなるため、表面部での反射波に着目すると、カバー表面からの反射波は小さく、主としてカバー裏面と、物体５０又はモデル７０との境界面からの成分が支配的となる。一方、誘電体材料の誘電率が大きく、物体５０又はモデル７０の誘電率に近い場合は、カバー表面からの反射波が支配的となる。そして、これらのいずれの場合も、反射波成分の打消しが可能であるため、反射波の生じる位置並びにそれを左右するカバー材質の誘電率は問題とはならない仕組みである。   The cover 80 is formed of a dielectric, but the signal analysis means 13 performs a process of canceling the reflected wave component on the surface of the cover, so that the relative dielectric constant is the medium surrounding the object and the cover (usually air). If it is a value between, it will not specifically limit. That is, when the relative dielectric constant of the dielectric material used as the cover is small, for example, when the relative dielectric constant is close to 2, the refractive index is close to 1, and the difference in refractive index from air is small. When attention is paid to the above, the reflected wave from the cover surface is small, and the component mainly from the boundary between the back surface of the cover and the object 50 or the model 70 is dominant. On the other hand, when the dielectric constant of the dielectric material is large and is close to the dielectric constant of the object 50 or the model 70, the reflected wave from the cover surface becomes dominant. In any of these cases, since the reflected wave component can be canceled, the position where the reflected wave is generated and the dielectric constant of the cover material that influences the position are not a problem.

さらに、物体５０としての胸部とカバー８０との間にわずかな隙間が空気層として残り、照射された超短パルスの新たな反射を招く、誘電率の異なる二つの物質の境界（カバー８０裏面と空気層との境界、空気層と物体５０との境界）が生じてしまうのを防ぐために、カバー８０と物体５０との位置関係を調整し、カバー８０を適切な押圧力で相対的に物体５０に向けて押付ける状態を得て、カバー８０を物体５０に密着させるほか、必要に応じて、カバー８０又は物体５０に近い誘電率となるジェルなどを塗布使用して隙間を埋めることで、より高精度の反射波信号の取得が行えるようにする。モデル７０に対してカバー８０を適用する場合も同様である。   Furthermore, a slight gap remains between the chest as the object 50 and the cover 80 as an air layer, and causes a new reflection of the irradiated ultrashort pulse, which is a boundary between two substances having different dielectric constants (from the back surface of the cover 80). In order to prevent the occurrence of the boundary between the air layer and the boundary between the air layer and the object 50), the positional relationship between the cover 80 and the object 50 is adjusted, and the cover 50 is relatively moved with an appropriate pressing force. In addition to bringing the cover 80 into close contact with the object 50 and filling the gap by applying and using a gel having a dielectric constant close to that of the cover 80 or the object 50 as necessary, A highly accurate reflected wave signal can be obtained. The same applies when the cover 80 is applied to the model 70.

例えば、物体５０を載せた支持台１８に、カバー８０に形成した張出し部分を固定する場合（図３参照）、支持台１８の物体５０を載せる部分の高さを調整して、カバー８０が物体５０に相対的に押付けられる状態を変え、カバー８０を物体５０と隙間無く密着させるようにする。ただし、支持台１８の物体５０を載せる部分を高くしすぎると、カバー８０で物体５０を過剰に押える状態となって物体５０とカバー８０の両方に力が加わり、物体５０やカバー８０の形状変化を招き、不要な隙間とそれに伴う誘電率の異なる二つの物質の境界面が新たに発生し、測定に悪影響を与えるため、前記高さは、物体５０やモデル７０、カバー８０の各弾性等の性質や形状に応じた適切な値を選択する。この他、物体５０の接する側を上に向けて固定したカバー８０に、上から物体５０やモデル７０を載せるようにして、こうした物体等の重みにより物体５０やモデル７０がカバー８０に適度に押付けられて密着する状態を得られる支持構成を採用してもよい。この場合、パルス送受信手段１１による測定はカバー８０の下方から行われることとなる。   For example, when the protruding portion formed on the cover 80 is fixed to the support base 18 on which the object 50 is placed (see FIG. 3), the height of the portion of the support base 18 on which the object 50 is placed is adjusted so that the cover 80 The state in which the cover 80 is pressed relative to the object 50 is changed, and the cover 80 is brought into close contact with the object 50 without a gap. However, if the portion on which the object 50 is placed on the support base 18 is too high, the object 50 is excessively pressed by the cover 80, and force is applied to both the object 50 and the cover 80, and the shape of the object 50 and the cover 80 changes. And an unnecessary gap and a boundary surface between two substances having different dielectric constants are newly generated and adversely affect the measurement. Select an appropriate value according to the property and shape. In addition, the object 50 or the model 70 is appropriately pressed against the cover 80 by the weight of the object 50 or the like so that the object 50 or the model 70 is placed from above on the cover 80 fixed with the contact side of the object 50 facing upward. It is also possible to adopt a support structure that can obtain a close contact state. In this case, measurement by the pulse transmission / reception means 11 is performed from below the cover 80.

また、カバー８０の厚さは、物体５０等の表面に被せる関係上、カバー自体の強度を維持できる範囲内で薄い方が好ましい。特に、カバー８０の厚さを、カバーをなす誘電体材料中での超短パルスの照射波及び反射波における実効波長の１／４に相当する寸法とした場合、カバー表面における入射波と反射波の相殺が生じることにより、物体やモデルにおける表面部からの反射波成分を減少させることができ、信号解析手段１３でのこうした表面部からの反射波成分の打消し処理を簡易に行えることとなり、好ましい。さらに、このカバー８０の厚さを前記１／４波長相当寸法とする場合に、カバー８０を物体５０やモデル７０より誘電率の高い誘電体材料、例えば、物体５０としての胸部組織の比誘電率が４〜１０の場合、カバー８０を比誘電率が１２〜２０となる材料で形成すれば、波長短縮効果によりカバーをなす誘電体中における実効波長が小さくなる関係から、実際のカバーの厚さを小さくすることができ、カバーの小型化及び材料削減が可能となり、より一層好ましい。   Further, the thickness of the cover 80 is preferably thin as long as the strength of the cover itself can be maintained because of covering the surface of the object 50 or the like. In particular, when the thickness of the cover 80 is set to a dimension corresponding to ¼ of the effective wavelength of the irradiation wave and the reflected wave of the ultrashort pulse in the dielectric material forming the cover, the incident wave and the reflected wave on the cover surface. , The reflected wave component from the surface portion of the object or model can be reduced, and the signal analysis means 13 can easily cancel the reflected wave component from the surface portion, preferable. Further, when the thickness of the cover 80 is set to the 1/4 wavelength equivalent dimension, the cover 80 is a dielectric material having a dielectric constant higher than that of the object 50 or the model 70, for example, the relative dielectric constant of breast tissue as the object 50. If the cover 80 is made of a material having a relative dielectric constant of 12 to 20, the effective thickness of the cover is reduced because the effective wavelength in the dielectric forming the cover is reduced by the wavelength shortening effect. It is possible to reduce the size of the cover, and it is possible to reduce the size and material of the cover.

なお、この乳がん検出用途、すなわち、物体５０が胸部組織で、検出対象物６０が腫瘍の場合、年齢やがん進行度合など、人体組織の差異によって物体５０としての胸部組織や検出対象物６０としての腫瘍の誘電率が異なる上、検出対象としたい腫瘍の大きさやその存在位置も反射波に大きく影響を与えることから、カバー８０やモデル７０の誘電率、形状等は、胸部組織や腫瘍の誘電率、検出対象としたい腫瘍の大きさやその存在位置により調整して、信号解析手段１３で物体表面部での反射波成分を適切に打消せるものとすることが好ましい。   In this breast cancer detection application, that is, when the object 50 is a breast tissue and the detection target 60 is a tumor, the breast tissue or the detection target 60 as the object 50 depends on the difference in human tissue such as age or cancer progression. Since the dielectric constants of the tumors are different and the size and location of the tumor to be detected greatly affect the reflected wave, the dielectric constant and shape of the cover 80 and the model 70 depend on the dielectric properties of the breast tissue and the tumor. It is preferable that the reflected wave component on the surface of the object can be appropriately canceled by the signal analysis means 13 by adjusting the rate and the size of the tumor to be detected and its position.

信号解析手段１３で、主副の各反射波信号を用いて、不要な成分である物体５０表面部での反射波成分を打消して検出対象物からの反射波成分を確実に際立たせることで、後の画像再構成で得られる画像における腫瘍とその他の部分とのコントラストを鮮明化することが可能となり、画像からの乳がん検出の精度を高められる。   The signal analysis unit 13 uses the main and sub reflected wave signals to cancel out the reflected wave components on the surface of the object 50, which are unnecessary components, so that the reflected wave components from the detection target are reliably made to stand out. The contrast between the tumor and other parts in the image obtained by the subsequent image reconstruction can be clarified, and the accuracy of breast cancer detection from the image can be improved.

そして、信号解析手段１３での、主反射波信号における表面部からの反射波成分の打消しに係る具体的な処理は、信号記録手段１２から読出した副反射波信号に、この副反射波信号の信号レベルに対する主反射波信号の信号レベルの割合を乗じて、規格化を行ったものを、主反射波信号から差引く、いわゆる規格化差分処理となっている。こうして、主反射波信号と副反射波信号の信号レベルを合わせることで、環境の変化や、測定条件などにより、主反射波信号と副反射波信号の信号レベルが大きくずれた場合にも、表面部からの反射波成分の打消しが適切に行える。このようにして主反射波信号における表面部での反射波成分を除去したものが、信号解析手段１３から、新たな反射波信号として信号記録手段１２を介して画像再構成手段１５に送出されることとなる。   Then, specific processing relating to cancellation of the reflected wave component from the surface portion in the main reflected wave signal in the signal analyzing unit 13 is performed on the sub reflected wave signal read from the signal recording unit 12. This is a so-called standardized difference process in which the signal that has been normalized by multiplying the ratio of the signal level of the main reflected wave signal to the signal level is subtracted from the main reflected wave signal. By matching the signal levels of the main reflected wave signal and the sub reflected wave signal in this way, even if the signal level of the main reflected wave signal and the sub reflected wave signal is greatly shifted due to environmental changes or measurement conditions, the surface It is possible to appropriately cancel the reflected wave component from the part. In this way, a signal obtained by removing the reflected wave component from the surface portion of the main reflected wave signal is sent from the signal analyzing unit 13 to the image reconstruction unit 15 via the signal recording unit 12 as a new reflected wave signal. It will be.

なお、検出対象物６０が腫瘍の場合、その進行度合により誘電率が変化し、この検出対象物６０の誘電率の違いによって、反射波の状態が変化し、画像再構成で得られる画像も、検出対象物６０とその他の部分とのコントラストが変化するといったような影響を受けることから、逆に誘電率の変化に基づいて、信号解析手段１３で反射波の変化状態を識別するようにして、がんの進行度合を判定することもできる。   In addition, when the detection target 60 is a tumor, the dielectric constant changes depending on the degree of progress thereof, and the state of the reflected wave changes due to the difference in the dielectric constant of the detection target 60, and an image obtained by image reconstruction is also Since the contrast between the detection target 60 and other portions is affected, the signal analysis means 13 identifies the change state of the reflected wave based on the change in the dielectric constant. The degree of cancer progression can also be determined.

信号解析手段１３による前記二つの反射波信号を用いた処理は、測定方向ごとに実行されて、そのつど新たな反射波信号が出力されることに伴い、信号解析手段１３が全ての測定方向について処理を実行して物体表面での反射波成分を打消した反射波信号を出力するまで、信号記録手段１２では、信号解析手段１３から出力された各測定方向ごとの反射波信号をデータとして記録して、この反射波信号のデータをまとめて画像再構成手段１５に提供できるようにしている。   The processing using the two reflected wave signals by the signal analyzing unit 13 is executed for each measurement direction, and each time a new reflected wave signal is output, the signal analyzing unit 13 performs all the measurement directions. The signal recording unit 12 records the reflected wave signal for each measurement direction output from the signal analyzing unit 13 as data until the reflected wave signal that cancels the reflected wave component on the object surface is output by executing the processing. Thus, the reflected wave signal data can be collectively provided to the image reconstruction means 15.

すなわち、画像再構成手段１５では全ての測定方向での反射波信号が得られた段階で合成開口処理を伴う画像再構成を実行する関係から、信号記録手段１２で、全ての測定方向での反射波信号が得られるまで、信号解析手段１３からの各測定方向ごとの反射波信号をデータとして記録し、全ての測定方向についての反射波信号のデータをまとめて画像再構成手段１５に提供することで、画像再構成手段１５での画像再構成が問題なく実行されるようにしている。   That is, the image reconstructing means 15 performs image reconstruction with synthetic aperture processing at the stage where the reflected wave signals in all measurement directions are obtained, so that the signal recording means 12 reflects in all measurement directions. Until the wave signal is obtained, the reflected wave signal for each measurement direction from the signal analysis unit 13 is recorded as data, and the reflected wave signal data for all measurement directions is collectively provided to the image reconstruction unit 15. Thus, the image reconstruction by the image reconstruction means 15 is executed without any problem.

前記画像再構成手段１５は、各方向ごとの複数の反射波信号から合成開口処理を伴う画像再構成を行い、物体中に検出対象物の示された画像（図１９〜図２１参照）を得るものである。合成開口処理を伴う画像再構成そのものは公知の手法であり、詳細な説明を省略する。   The image reconstruction means 15 performs image reconstruction with synthetic aperture processing from a plurality of reflected wave signals in each direction, and obtains an image (see FIGS. 19 to 21) in which an object to be detected is shown. Is. Image reconstruction itself with synthetic aperture processing is a well-known technique and will not be described in detail.

前記表示手段１６は、画像再構成手段１５での画像再構成により得られた画像を表示画面上に表示するものであり、その構成自体は、ＣＲＴや液晶、有機ＥＬ等を表示用デバイスとして使用した公知のディスプレイ装置と同様のものであり、説明を省略する。なお、この表示手段１６を、後述するコンピュータのディスプレイ装置が兼ねるようにしてもかまわない。   The display unit 16 displays an image obtained by the image reconstruction by the image reconstruction unit 15 on a display screen, and the configuration itself uses a CRT, a liquid crystal, an organic EL, or the like as a display device. This is the same as the known display device described above, and a description thereof will be omitted. The display means 16 may also be used as a computer display device to be described later.

前記パルス送受信手段１１の制御部１１ｆ、信号記録手段１２、信号解析手段１３、及び、画像再構成手段１５は、そのハードウェア構成として、ＣＰＵやメモリ、入出力インターフェース等を備えるコンピュータとなっており、メモリ等に格納されるプログラムにより、コンピュータを前記制御部１１ｆ、信号記録手段１２、信号解析手段１３、及び、画像再構成手段１５として動作させる仕組みである。パルス送受信手段１１で得られた反射波信号や、信号解析手段１３で得られた主反射波信号に基づく新たな反射波信号等の測定、算出結果は、信号記録手段１２をなすこのコンピュータのメモリ等に各角度位置での測定毎に記録保存される。なお、前記信号記録手段１２、信号解析手段１３、及び、画像再構成手段１５は、それぞれ独立に、あるいは複数まとめた状態として、複数のコンピュータをなすものとすることもできる。また、こうしたコンピュータは、ＣＰＵやメモリ、ＲＯＭ等を一体的に形成されたマイクロコンピュータとしてもかまわない。   The control unit 11f, the signal recording unit 12, the signal analysis unit 13, and the image reconstruction unit 15 of the pulse transmission / reception unit 11 are computers including a CPU, a memory, an input / output interface, and the like as hardware configurations. The computer is operated as the control unit 11f, the signal recording unit 12, the signal analysis unit 13, and the image reconstruction unit 15 by a program stored in a memory or the like. Measurement and calculation results of the reflected wave signal obtained by the pulse transmitting / receiving means 11 and the new reflected wave signal based on the main reflected wave signal obtained by the signal analyzing means 13 are stored in the memory of this computer forming the signal recording means 12. For example, it is recorded and stored for each measurement at each angular position. The signal recording means 12, the signal analysis means 13, and the image reconstruction means 15 can be configured as a plurality of computers independently or in a state where a plurality of them are collected. Further, such a computer may be a microcomputer in which a CPU, a memory, a ROM, and the like are integrally formed.

次に、本実施形態に係るマイクロ波イメージングシステムの使用状態について説明する。まず、後述する物体５０の場合と同じカバー８０を被せたモデル７０に対し、あらかじめ設定された測定時間（例えば、３２ミリ秒）の間、パルス送受信手段１１の各アンテナ１１ａ、１１ｂが、アンテナ移動機構１１ｄにより測定開始角度位置（０°）に位置して、この角度に対応する測定方向を向いた照射アンテナ１１ａから超短パルスを照射すると共に、カバー８０及びモデル７０からの反射波を受信アンテナ１１ｂで受信し、反射波を信号入出力部１１ｅで処理して得た反射波信号を信号記録手段１２に入力する。   Next, the usage state of the microwave imaging system according to the present embodiment will be described. First, with respect to the model 70 covered with the same cover 80 as that of the object 50 to be described later, the antennas 11a and 11b of the pulse transmitting / receiving unit 11 move the antenna for a preset measurement time (for example, 32 milliseconds). The mechanism 11d is positioned at the measurement start angle position (0 °) and irradiates an ultrashort pulse from the irradiation antenna 11a facing the measurement direction corresponding to this angle, and receives the reflected wave from the cover 80 and the model 70 as a reception antenna. The reflected wave signal received by 11b and processed by the signal input / output unit 11e is input to the signal recording means 12.

こうした測定の際、モデル７０に被せたカバー８０をモデル側に押すかモデル７０をカバー８０側へ押すようにして、カバー８０がモデル７０に相対的に押付けられる状態として、カバー８０をモデル７０と隙間無く密着させるのが好ましい。   In such a measurement, the cover 80 is pressed against the model 70 so that the cover 80 is pressed against the model 70 by pressing the cover 80 on the model 70 toward the model side or pressing the model 70 toward the cover 80 side. It is preferable to make it closely contact with no gap.

信号記録手段１２は入力された反射波信号を副反射波信号として記録する。
この測定角度位置でのパルス送受信手段１１からの反射波信号が信号記録手段１２に記録されたら、アンテナ移動機構１１ｄを動作させて各アンテナ１１ａ、１１ｂを次の角度位置に移行させ、前記同様の測定及び処理を実行し、これを全ての測定角度位置（１８０°まで）について繰返し行う。
モデル７０に対し全ての測定角度位置での測定を終了し、モデル７０についての各測定方向ごとの副反射波信号が全て得られたら、続いて、物体５０に対しての測定を実行する。 The signal recording means 12 records the input reflected wave signal as a sub reflected wave signal.
When the reflected wave signal from the pulse transmission / reception means 11 at the measurement angular position is recorded in the signal recording means 12, the antenna moving mechanism 11d is operated to move each antenna 11a, 11b to the next angular position, and the same as described above. Measurement and processing are performed and this is repeated for all measurement angular positions (up to 180 °).
When the measurement at all measurement angle positions with respect to the model 70 is finished and all the sub reflected wave signals for each measurement direction for the model 70 are obtained, the measurement for the object 50 is subsequently executed.

物体５０としての胸部組織に対し、モデル７０の場合と同一の、適切な大きさのカバー８０を被せた状態で、あらかじめ設定された測定時間（例えば、３２ミリ秒）の間、パルス送受信手段１１が、アンテナ移動機構１１ｄにより測定開始角度位置（０°）に位置して、この角度に対応する測定方向を向いた照射アンテナ１１ａから超短パルスを照射すると共に、カバー８０、物体５０及び検出対象物６０からの反射波を受信アンテナ１１ｂで受信し、反射波を信号入出力部１１ｅで処理して得た反射波信号を主反射波信号として信号解析手段１３に入力する。   The pulse transmission / reception means 11 is set for a predetermined measurement time (for example, 32 milliseconds) in a state in which the breast tissue as the object 50 is covered with a cover 80 having the same size as that of the model 70. Is positioned at the measurement start angle position (0 °) by the antenna moving mechanism 11d, and irradiates an ultrashort pulse from the irradiation antenna 11a facing the measurement direction corresponding to this angle, and the cover 80, the object 50, and the detection target The reflected wave from the object 60 is received by the receiving antenna 11b, and the reflected wave signal obtained by processing the reflected wave by the signal input / output unit 11e is input to the signal analyzing means 13 as the main reflected wave signal.

こうした測定の際は、モデル７０の場合と同様、物体５０に被せたカバー８０を物体側に押すか物体５０をカバー８０側へ押すようにして、カバー８０が物体５０に相対的に押付けられる状態として、カバー８０を物体５０と隙間無く密着させるのが好ましい。   In the case of such measurement, as in the case of the model 70, the cover 80 is pressed against the object 50 by pressing the cover 80 covering the object 50 toward the object side or pressing the object 50 toward the cover 80 side. As described above, it is preferable that the cover 80 is in close contact with the object 50 without any gap.

信号解析手段１３は、パルス送受信手段１１から物体５０についての主反射波信号（図５参照）を取得する一方、信号記録手段１２から物体５０における測定方向と同じ測定方向の副反射波信号（図６参照）を読出す。   The signal analysis unit 13 obtains the main reflected wave signal (see FIG. 5) for the object 50 from the pulse transmitting / receiving unit 11, while the sub reflected wave signal (see FIG. 5) in the same measurement direction as that of the object 50 from the signal recording unit 12. 6).

ここで、主反射波信号には、カバー８０のある物体５０表面部での反射波成分や、検出対象物６０が存在する場合における検出対象物６０からの反射波成分等が所定の信号レベルで含まれている。また、副反射波信号には、カバー８０のあるモデル７０表面部での反射波成分が含まれている。   Here, the main reflected wave signal includes a reflected wave component on the surface of the object 50 with the cover 80, a reflected wave component from the detection target 60 when the detection target 60 exists, and the like at a predetermined signal level. include. Further, the sub reflected wave signal includes a reflected wave component at the surface of the model 70 where the cover 80 is provided.

信号解析手段１３は、副反射波信号が、主反射波信号とほぼ同様の信号レベルである場合は、そのまま主反射波信号から副反射波信号を差引いてもよいが、副反射波信号の信号レベルが、主反射波信号とは大きく異なっている場合には、前記副反射波信号に、副反射波信号に対する主反射波信号の信号レベルの割合を乗じて、規格化を行ったものを、主反射波信号から差引く処理を実行する。   When the sub-reflected wave signal has substantially the same signal level as the main reflected wave signal, the signal analyzing unit 13 may subtract the sub-reflected wave signal from the main reflected wave signal as it is. When the level is significantly different from the main reflected wave signal, the sub reflected wave signal is multiplied by the ratio of the signal level of the main reflected wave signal to the sub reflected wave signal, and normalized, A process of subtracting from the main reflected wave signal is executed.

主反射波信号における物体５０表面部での反射波成分と副反射波信号におけるモデル７０表面部での反射波成分とがほぼ同様のものとなっていることから、主反射波信号に含まれる物体５０表面部での反射成分が、副反射波信号に含まれるモデル７０表面部での反射成分で打消されて除去され、主反射波信号における検出対象物６０からの反射成分が相対的に強調されることとなる。信号解析手段１３では、この物体５０表面部での反射波成分が打消された主反射波信号を、新たな反射波信号（図７参照）とする。   Since the reflected wave component at the surface of the object 50 in the main reflected wave signal and the reflected wave component at the surface of the model 70 in the sub-reflected wave signal are substantially the same, the object included in the main reflected wave signal The reflection component on the surface 50 is canceled out by the reflection component on the surface of the model 70 included in the sub-reflection signal, and the reflection component from the detection target 60 in the main reflection signal is relatively emphasized. The Rukoto. In the signal analysis means 13, the main reflected wave signal in which the reflected wave component at the surface of the object 50 is canceled is set as a new reflected wave signal (see FIG. 7).

この時、信号解析手段１３は、超短パルスを照射する物体５０としての***や検出対象物６０としての腫瘍の各誘電率、並びに検出しようとする腫瘍の大きさや胸部組織における位置関係に基づいて、実際に解析対象とする周波数範囲を限定することもできる。具体的には、信号解析手段１３が、反射波信号をフーリエ変換し、得られた周波数領域の信号から不要帯域の信号成分を除去し、解析対象としてあらかじめ設定された周波数範囲に合致する信号成分のみを抽出し、この信号成分を逆フーリエ変換して、時間領域の信号に戻すプロセスを経て、解析対象の周波数範囲を適切なものとした主反射波信号と副反射波信号を得ることとなる。周波数領域でのフィルタリングで、主反射波信号における検出対象物６０からの反射波成分がノイズから分離して相対的に強調された状態を得られ、画像再構成等を経て検出対象物を示すイメージを正確に導くことができる。これについては、主反射波信号を、解析対象の周波数範囲のみ通過させる第一のフィルタ回路に通して調整後の主反射波信号を得ると共に、副反射波信号を前記周波数範囲のみ通過させる第二のフィルタ回路に通して調整後の副反射波信号を得るなど、ハードウェアによるフィルタリングを行うようにすることもできる。   At this time, the signal analysis means 13 is based on the dielectric constants of the breast as the object 50 to be irradiated with the ultrashort pulse and the tumor as the detection target 60, the size of the tumor to be detected, and the positional relationship in the breast tissue. It is also possible to limit the frequency range that is actually analyzed. Specifically, the signal analysis unit 13 performs Fourier transform on the reflected wave signal, removes unnecessary band signal components from the obtained frequency domain signal, and matches the frequency range preset as the analysis target. The main reflected wave signal and the sub reflected wave signal with the appropriate frequency range to be analyzed are obtained through the process of extracting only the signal component, inverse Fourier transforming this signal component, and returning it to the time domain signal. . By filtering in the frequency domain, it is possible to obtain a state in which the reflected wave component from the detection target 60 in the main reflected wave signal is separated from noise and is relatively emphasized, and shows the detection target through image reconstruction and the like. Can be guided accurately. For this, the main reflected wave signal is passed through the first filter circuit that passes only the frequency range to be analyzed to obtain the adjusted main reflected wave signal, and the second reflected wave signal is passed only in the frequency range. It is also possible to perform filtering by hardware, such as obtaining an adjusted sub-reflection signal through a filter circuit.

また、信号解析手段１３は、反射波信号において検出対象物６０の表面からの反射波成分が、どれだけの時間経過後に現れるかが事前にある程度予測できることから、検出対象物６０の表面からの反射波が到来し得ない時間帯をフィルタリングする、時間フィルタリングを実行することもできる。例えば、乳がん検出を行う場合、体表面から１ｃｍ以内は腫瘍の存在確率が小さく、また触診等、より容易な他の手法による腫瘍の有無の確認精度が高いことから、その範囲分の反射波が到来する時間まではカットすることができ、また、胸部組織（***）全域の反射波が既に到来したと見なせる時間以降も、同様にカットすることで、反射波信号のデータ量を抑え、後の画像再構成等における処理負荷の軽減を図ることができると共に、検出対象物６０である腫瘍からの反射波成分を明確化して画像化の精度を高められ、検出精度向上に繋げられる。   Further, since the signal analysis unit 13 can predict to some extent in advance how long the reflected wave component from the surface of the detection target 60 appears in the reflected wave signal, the reflection from the surface of the detection target 60 is performed. Temporal filtering can also be performed to filter time zones when waves cannot arrive. For example, when performing breast cancer detection, the presence probability of a tumor is small within 1 cm from the body surface, and the accuracy of confirmation of the presence or absence of a tumor by other easier methods such as palpation is high. It can be cut until the arrival time, and after the time when the reflected wave of the whole breast tissue (breast) can be considered to have already arrived, the data amount of the reflected wave signal can be reduced by cutting in the same way. The processing load in image reconstruction or the like can be reduced, and the reflected wave component from the tumor that is the detection target 60 can be clarified to improve the imaging accuracy, leading to improved detection accuracy.

この時間フィルタリングにおいても、物体５０としての胸部組織や検出対象物６０としての腫瘍の誘電率の変化、検出対象としたい腫瘍の大きさやその存在位置の変化に応じて、フィルタリングの特性を変化させる、具体的には検出対象物６０の表面からの反射波が到来し得ない時間帯と見なしてカットする時間の幅を変えるようにすることもでき、画像再構成で得られる画像における検出対象物６０のより一層の鮮明化が図れることとなる。   Also in this temporal filtering, the filtering characteristics are changed according to the change in the dielectric constant of the breast tissue as the object 50 and the change in the dielectric constant of the tumor as the detection target 60, the size of the tumor to be detected, and the change in the position thereof. Specifically, it is also possible to change the width of the cut time considering that the reflected wave from the surface of the detection object 60 cannot arrive, and to detect the detection object 60 in the image obtained by image reconstruction. It will be possible to further clarify.

信号解析手段１３により、物体５０表面での反射波成分が打消されて、検出対象物６０からの反射成分が明瞭となった主反射波信号を、新たにこの測定方向での反射波信号として信号記録手段１２に記録したら、アンテナ移動機構１１ｄを動作させて各アンテナ１１ａ、１１ｂを次の角度位置に移行させ、前記同様の測定及び処理を実行し、これを全ての測定角度位置（１８０°まで）について繰返し行う。   The main reflected wave signal in which the reflected wave component on the surface of the object 50 is canceled by the signal analyzing means 13 and the reflected component from the detection target 60 becomes clear is newly generated as a reflected wave signal in this measurement direction. After recording in the recording means 12, the antenna moving mechanism 11d is operated to move each antenna 11a, 11b to the next angular position, and the same measurement and processing as described above are performed, and this is performed for all measurement angular positions (up to 180 °). ) Repeatedly.

物体５０に対し全ての測定角度位置での測定を終了し、各測定方向ごとの反射波信号が全て得られたら、画像再構成手段１５が、信号記録手段１２から読出した各測定方向ごとの反射波信号を用いて、合成開口処理により画像再構成を行う。これにより、物体５０内に検出対象物６０が存在する場合には、この検出対象物６０が明確に画像化された物体５０内部の画像が取得され、この画像が表示手段１６に表示されることとなる。表示された画像から、検出対象物６０の有無や状態を判断することができる。   When the measurement at all the measurement angle positions with respect to the object 50 is completed and all the reflected wave signals for each measurement direction are obtained, the image reconstruction means 15 reflects the reflection for each measurement direction read from the signal recording means 12. Image reconstruction is performed by synthetic aperture processing using a wave signal. Thereby, when the detection target 60 exists in the object 50, an image inside the object 50 in which the detection target 60 is clearly imaged is acquired and displayed on the display unit 16. It becomes. From the displayed image, the presence / absence and state of the detection target 60 can be determined.

ここで、カバー８０を被せた物体５０とモデル７０を用いて、物体５０表面部の反射波成分を打消す処理を適用した場合の、ノイズ低減効果の例を画像化して示す。物体５０とみなす胸部ファントム（ただし検出対象物は含まない）と、このファントムと同一形状ではないが近い形状の、モデルとしての別の胸部ファントムをそれぞれ用意し、各々の表面に胸部を模したカバー８０を被せて覆い、カバー８０と各ファントムとをそれぞれ密着させた条件で、各ファントムについてそれぞれ反射波信号を取得した。これら二つの反射波信号を用いて、物体５０をなすファントムの反射波信号における表面部の反射波成分を打消す処理を、各測定方向ごとに行って得られた新たな反射波信号を、全ての測定方向分を一つの表示にまとめて画像化した信号強度図を、図８に示す。   Here, an example of the noise reduction effect in the case of applying the processing of canceling the reflected wave component on the surface of the object 50 using the object 50 and the model 70 covered with the cover 80 is shown as an image. A chest phantom to be regarded as the object 50 (but not including the detection target) and another chest phantom as a model that is not the same shape as this phantom, but a close shape, are prepared, and the covers imitating the chest on each surface The reflected wave signal was acquired for each phantom under the condition that the cover 80 was covered and the cover 80 and each phantom were in close contact with each other. Using these two reflected wave signals, all the new reflected wave signals obtained by performing the processing for canceling the reflected wave component of the surface portion in the reflected wave signal of the phantom forming the object 50 for each measurement direction FIG. 8 shows a signal intensity diagram in which the measurement directions are collectively displayed in one display.

また、比較のために、前記同様の二つのファントムにカバー８０を適用しない状態で、各ファントムについてそれぞれ反射波信号を取得し、物体５０をなすファントムの反射波信号における表面部の反射波成分を打消す処理を行って得られた新たな反射波信号を、前記同様に全ての測定方向分を一つの表示にまとめて画像化したものを、図９に示す。なお、前記各図の縦軸（左）は物体（又はモデル）に対する測定方向と対応するアンテナの角度位置［ｄｅｇ．］、横軸は計測時間［ｎｓ］で、明暗（右）が反射波信号のピークの信号レベル［Ｖ］、すなわちノイズ成分の大小を示す（明るいほど大）。   For comparison, a reflected wave signal is acquired for each phantom in a state where the cover 80 is not applied to the two similar phantoms, and the reflected wave component of the surface portion in the reflected wave signal of the phantom forming the object 50 is obtained. FIG. 9 shows an image of a new reflected wave signal obtained by performing the canceling process in which all the measurement directions are combined into a single display as described above. In each figure, the vertical axis (left) represents the antenna angular position corresponding to the measurement direction with respect to the object (or model) [deg. ], The horizontal axis is the measurement time [ns], and the brightness (right) indicates the signal level [V] of the peak of the reflected wave signal, that is, the magnitude of the noise component (the brighter the greater).

図８及び図９から、物体及びモデルとしての各ファントムにカバー８０を被せた状態について処理を行い画像化した結果の方が、カバー３１を用いない状態について処理を実行して画像化した結果に比べて、ノイズ分である表面部の反射波成分を表すピーク（明部）の信号レベル及びその周辺部の信号レベルが、各図中の右側の信号レベルを示す明暗遷移帯の強度表示値に見られるように小さくなっており、表面部の反射波成分が打消しの処理を経て小さくなる分、画像再構成で得られる画像中に表面部の反射波成分は現れにくくなって、検出対象物が存在する場合にはこれを画像中でより明確に示せることがわかる。   From FIG. 8 and FIG. 9, the result of processing and imaging the object and the state where each phantom as a model is covered with the cover 80 is the result of executing processing and imaging for the state where the cover 31 is not used. In comparison, the signal level of the peak (bright part) representing the reflected wave component of the surface part, which is the noise component, and the signal level of the peripheral part thereof are the intensity display values of the light-dark transition band indicating the signal level on the right side in each figure. Since the reflected wave component on the surface becomes small as seen, the reflected wave component on the surface becomes difficult to appear in the image obtained by image reconstruction because the reflected wave component on the surface becomes small after cancellation processing. It can be seen that this can be shown more clearly in the image.

このように、本実施形態に係るマイクロ波イメージングシステムは、パルス送受信手段１１から出力された反射波信号をいったん信号記録手段１２に記録して、この記録された反射波信号と別の反射波信号との比較解析を信号解析手段１３で実行可能とし、対象物の検出を行おうとする物体５０にこの物体表面形状を模したカバー８０を被せた状態で取得した主反射波信号と、物体５０に近い誘電率の材料を用いて製作された物体モデル７０にカバー８０を被せた状態で取得した副反射波信号とを、信号解析手段で比較解析し、主反射波信号における表面部からの反射波成分から副反射波信号における表面部からの反射波成分を差引き、検出対象物６０からの反射波成分を残しつつ表面での反射波成分を打消している。   As described above, the microwave imaging system according to the present embodiment temporarily records the reflected wave signal output from the pulse transmission / reception unit 11 in the signal recording unit 12 and separates the recorded reflected wave signal from the reflected wave signal. The signal analysis means 13 can execute the comparison analysis with the main reflected wave signal acquired in a state where the object 50 to be detected is covered with the cover 80 imitating the object surface shape, and the object 50. A side reflected wave signal acquired in the state where the object model 70 manufactured using a material having a close dielectric constant is covered with the cover 80 is compared and analyzed by a signal analyzing means, and the reflected wave from the surface portion in the main reflected wave signal is analyzed. The reflected wave component from the surface portion in the sub reflected wave signal is subtracted from the component, and the reflected wave component on the surface is canceled while the reflected wave component from the detection target 60 is left.

これにより、主反射波信号における検出対象物６０からの反射波成分にほとんど影響を与えずに、効率よく表面での反射波成分を取除いて、主反射波信号での検出対象物６０からの反射波成分を相対的に強調できることとなり、物体５０表面での反射波成分の存在に関わりなく検出対象物６０からの反射波成分を確実に取得でき、画像再構成で検出対象物６０の画像化を精度よく実行可能となり、得られた画像から検出対象物６０を適切に検出、評価できる。   As a result, the reflected wave component from the detection target 60 in the main reflected wave signal is efficiently removed without affecting the reflected wave component from the detection target 60 in the main reflected wave signal. The reflected wave component can be relatively emphasized, the reflected wave component from the detection target 60 can be reliably acquired regardless of the presence of the reflected wave component on the surface of the object 50, and the detection target 60 is imaged by image reconstruction. Can be accurately executed, and the detection target 60 can be appropriately detected and evaluated from the obtained image.

胸部組織である物体５０からこの胸部組織内の腫瘍である検出対象物６０を検出しようとする乳がん検出の場合、信号解析手段１３で、物体５０についての主反射波信号から、物体５０表面部での反射波成分を適切に打消すことで、検出対象物６０としての腫瘍からの反射波成分を相対的に際立たせることとなり、後の画像再構成の処理を経て、胸部組織内部の画像における腫瘍の画像部分を鮮明に取得でき、乳がん検出の精度を高められる。   In the case of breast cancer detection in which the detection object 60 that is a tumor in the breast tissue is to be detected from the object 50 that is the breast tissue, the signal analysis unit 13 uses the main reflected wave signal for the object 50 to detect the target object 60 on the surface of the object 50. By appropriately canceling the reflected wave component, the reflected wave component from the tumor as the detection target 60 is made to stand out relatively, and the tumor in the image inside the breast tissue is processed through a subsequent image reconstruction process. Can be obtained clearly and breast cancer detection accuracy can be improved.

なお、前記第１の実施形態に係るマイクロ波イメージングシステムにおいては、物体５０に被せるカバーと同じものであることが既知であるカバー８０を、モデル７０に被せて、パルス送受信手段１１で測定動作を実行して反射波信号を出力し、これを信号記録手段１２に記録して副反射波信号とし、この副反射波信号を、信号解析手段１３で主反射波信号における表面部での反射波成分打消しの際に信号記録手段１２から読出して用いる構成としているが、これに限らず、あらかじめ、複数種類のカバーをそれぞれモデル７０に被せてパルス送受信手段１１で測定動作を実行してそれぞれ反射波信号を得てから、この反射波信号をカバーごとの副反射波信号として信号記録手段にまとめて記録しておき、物体５０についてパルス送受信手段１１で測定動作を行う時点で実際に物体に適用するカバーが決ったら、信号記録手段からそのカバーに対応する副反射波信号を信号解析手段が読出して解析に用いるようにすることもできる。   In the microwave imaging system according to the first embodiment, the cover 80, which is known to be the same as the cover to be placed on the object 50, is put on the model 70, and the pulse transmitting / receiving means 11 performs the measurement operation. The reflected wave signal is output and recorded in the signal recording means 12 to be a sub-reflected wave signal. This sub-reflected wave signal is reflected by the signal analyzing means 13 on the surface of the main reflected wave signal. However, the present invention is not limited to this, and is not limited to this, and a plurality of types of covers are put on the model 70 in advance, and the pulse transmission / reception means 11 performs a measurement operation to reflect each reflected wave. After obtaining the signal, this reflected wave signal is collectively recorded in the signal recording means as a sub reflected wave signal for each cover, and the object 50 is subjected to pulse transmission / reception means. When actually decided cover to be applied to the object at the time of performing the measurement operation in 1, the secondary reflecting wave signal signal analysis means corresponding the signal recording means on the cover may be so used in the analysis is read.

この場合、物体についての主反射波信号を取得し解析する機会に、そのつど、物体と同じカバーを被せたモデルについて、パルス送受信手段１１で測定動作を実行し反射波信号を得ておく手間を省くことができ、多数の物体についてカバーを変えながら反射波信号を取得してその解析を順次行うような場合（例えば、乳がんの集団検診など）に、測定と解析、再構成後の画像からの検出対象物の検出が、一連でスムーズに進められる   In this case, every time the main reflected wave signal for the object is acquired and analyzed, the measurement operation is performed by the pulse transmission / reception means 11 for the model covered with the same cover as the object, and the trouble of obtaining the reflected wave signal is saved. In cases where reflected signals are acquired and the analysis is performed sequentially while changing the cover for a large number of objects (for example, mass screening for breast cancer, etc.), measurement, analysis, and reconstruction from images after reconstruction The detection of the detection target can proceed smoothly in a series.

また、前記第１の実施形態に係るマイクロ波イメージングシステムにおいては、一の反射波信号として先にパルス送受信手段１１での測定動作を経て出力され、信号記録手段１２に記録される反射波信号が、モデルについての副反射波信号であり、他の反射波信号として、後でパルス送受信手段１１での新たな測定動作を経て出力され、信号解析手段１３で前記一の反射波信号と共に解析される反射波信号が、物体についての主反射波信号である、すなわち、モデルについての副反射波信号を得て記録した後、物体についての主反射波信号を得つつ解析を行う構成としているが、これに限らず、前記の場合と逆に、一の反射波信号が主反射波信号となり、他の反射波信号が副反射波信号となる、つまり、物体についての主反射波信号を得ていったん記録した後に、モデルについての副反射波信号を得つつ解析を行う構成としてもかまわない。   In the microwave imaging system according to the first embodiment, a reflected wave signal that is output as a reflected wave signal through the measurement operation of the pulse transmitting / receiving unit 11 and recorded in the signal recording unit 12 is provided. , A sub-reflected wave signal for the model, which is output as another reflected wave signal later through a new measurement operation in the pulse transmitting / receiving means 11 and analyzed by the signal analyzing means 13 together with the one reflected wave signal. The reflected wave signal is the main reflected wave signal for the object, that is, after obtaining and recording the secondary reflected wave signal for the model, the analysis is performed while obtaining the main reflected wave signal for the object. In contrast to the above case, one reflected wave signal becomes the main reflected wave signal and the other reflected wave signal becomes the sub reflected wave signal, that is, the main reflected wave signal for the object is obtained. After sputum recorded, may be configured to perform analysis while obtaining sub reflected wave signal for the model.

前記第１の実施形態に係るマイクロ波イメージングシステムにおいては、信号解析手段１３での主反射波信号における表面部からの反射波成分の打消し処理として、副反射波信号に、この副反射波信号の信号レベルに対する主反射波信号の信号レベルの割合を乗じて、規格化を行ったものを、主反射波信号から差引く処理を、信号解析手段１３に実行させる構成としているが、これに限らず、他の打消し処理として、信号解析手段が、主反射波信号に、主反射波信号の信号レベルに対する副反射波信号の信号レベルの割合を乗じて、規格化を行ったものから、副反射波信号を差引く処理を実行する構成とすることもでき、前記実施形態同様、環境の変化や、測定条件などにより、主反射波信号と副反射波信号の信号レベルが大きくずれた場合でも、表面部からの反射波成分の打消しを適切に行って、確実に検出対象物からの反射波成分を際立たせた新たな反射波信号を得ることができる。   In the microwave imaging system according to the first embodiment, as a process of canceling the reflected wave component from the surface portion of the main reflected wave signal in the signal analyzing unit 13, the sub reflected wave signal is converted into the sub reflected wave signal. The signal analysis means 13 is configured to execute the process of subtracting the signal that has been normalized by multiplying the ratio of the signal level of the main reflected wave signal to the signal level of the signal from the main reflected wave signal. First, as another cancellation process, the signal analysis unit multiplies the main reflected wave signal by the ratio of the signal level of the sub-reflected wave signal to the signal level of the main reflected wave signal, and performs the subtraction. It can also be configured to execute a process of subtracting the reflected wave signal, and when the signal levels of the main reflected wave signal and the sub reflected wave signal greatly deviate due to environmental changes, measurement conditions, etc., as in the previous embodiment. Also, it is possible to cancellation of the reflected wave component from the surface portion assigned to the right to obtain a new reflected wave signal highlights the reflected wave component from the detected reliably object.

また、前記第１の実施形態に係るマイクロ波イメージングシステムにおいては、信号解析手段１３で必要に応じ時間フィルタリングを実行することで、不要な時間帯の反射波信号の他、照射アンテナ１１ａからの照射後に反射によらず極短時間で受信アンテナ１１ｂに直接到達するクロストーク成分も同時に除去できる構成としているが、この他、パルスの送受信を行えば発生するクロストーク成分をあらかじめ把握し、実際に物体や検出対象物から反射された反射波信号からこのクロストーク成分を減算して、クロストーク成分の除去された反射波信号を得る構成とすることもでき、検出対象物からの反射波成分を含む反射波信号から確実に不要なクロストーク成分を除去して、反射波信号のＳ／Ｎ比を高め、検出対象物からの反射波成分を際立たせることができ、画像再構成で得られる画像における検出対象物の画像化の精度を高めて検出対象物の検出性向上が図れると共に、各信号成分の抽出取得から画像再構成までの計算処理量を軽減できる。   In the microwave imaging system according to the first embodiment, the signal analysis unit 13 performs time filtering as necessary, so that the reflected wave signal in the unnecessary time zone and the irradiation from the irradiation antenna 11a are irradiated. The crosstalk component that directly reaches the receiving antenna 11b in a very short time without being reflected later can be removed at the same time. In addition to this, the crosstalk component generated by transmitting and receiving pulses is grasped in advance, and the object is actually detected. In addition, the crosstalk component can be subtracted from the reflected wave signal reflected from the detection target object to obtain a reflected wave signal from which the crosstalk component has been removed, including the reflected wave component from the detection target object. The unwanted crosstalk component is reliably removed from the reflected wave signal, the S / N ratio of the reflected wave signal is increased, and the reflected wave component from the object to be detected It is possible to make it stand out and improve the detectability of the detection target by improving the accuracy of imaging of the detection target in the image obtained by image reconstruction, and the calculation processing from the acquisition acquisition of each signal component to the image reconstruction The amount can be reduced.

（本発明の第２の実施形態）
前記第１の実施形態に係るマイクロ波イメージングシステムにおいては、物体５０とモデル７０にそれぞれ同じカバー８０を被せることで表面形状の同一化を図り、信号解析手段１３で表面部の反射波成分を除去可能とする構成としているが、これに限らず、第２の実施形態として、図１０に示すように、物体５０の表面形状と同じ表面形状に形成したモデル７１を用い、カバーは使用しない構成とすることもできる。
この場合も、前記第１の実施形態同様、パルス送受信手段１１から出力された一の反射波信号をいったん信号記録手段１２に記録し、新たに出力される他の反射波信号との比較解析を信号解析手段１３で実行可能とする構成を用いる。 (Second embodiment of the present invention)
In the microwave imaging system according to the first embodiment, the object 50 and the model 70 are each covered with the same cover 80 to make the surface shape identical, and the signal analysis means 13 removes the reflected wave component on the surface portion. However, the present invention is not limited to this, and as a second embodiment, as shown in FIG. 10, a model 71 formed with the same surface shape as the surface shape of the object 50 is used and a cover is not used. You can also
Also in this case, as in the first embodiment, one reflected wave signal output from the pulse transmitting / receiving unit 11 is once recorded in the signal recording unit 12, and compared with another newly output reflected wave signal. A configuration that can be executed by the signal analysis means 13 is used.

なお、いったん信号記録手段１２に記録されてから読出される一の反射波信号は、誘電体材料、好ましくは、物体５０の誘電率に近い誘電率となる材料を用いて形成された物体のモデル７１について、パルス送受信手段１１で各方向ごとに所定時間にわたり超短パルスを照射し且つ反射波を受信することで得られる反射波信号である。   The one reflected wave signal once recorded after being recorded in the signal recording means 12 is a model of an object formed using a dielectric material, preferably a material having a dielectric constant close to that of the object 50. Reference numeral 71 denotes a reflected wave signal obtained by irradiating the pulse transmitting / receiving means 11 with an ultrashort pulse for each predetermined direction for each direction and receiving the reflected wave.

また、新たにパルス送受信手段１１から出力される他の反射波信号は、物体５０にパルス送受信手段１１で各方向ごとに所定時間にわたり超短パルスを照射し且つ反射波を受信することで得られる反射波信号である。この他の反射波信号を、物体５０に対応する点から主反射波信号とし、前記一の反射波信号を副反射波信号とする点は、前記第１の実施形態と同様である。   Further, another reflected wave signal newly output from the pulse transmitting / receiving means 11 is obtained by irradiating the object 50 with an ultrashort pulse for each predetermined time in each direction by the pulse transmitting / receiving means 11 and receiving the reflected wave. This is a reflected wave signal. The other reflected wave signals are the main reflected wave signals from the point corresponding to the object 50, and the one reflected wave signal is the sub reflected wave signal, as in the first embodiment.

信号解析手段１３において、対象物の検出を行おうとする物体５０について取得された主反射波信号と、物体５０の表面形状に略一致する表面形状を有するモデル７１について取得され、信号記録手段１２に記録されていた副反射波信号とをそれぞれ比較すると、物体５０内部やモデル７１内部からの反射波成分については信号強度の大きな差が生じるものの、同様の形状である表面部での反射波成分については同様の信号強度となることに基づき、主反射波信号における表面部からの反射波成分から副反射波信号における表面部からの反射波成分を差引き、検出対象物からの反射波成分を残しつつ表面での反射波成分を打消す処理を実行する。   The signal analysis unit 13 acquires the main reflected wave signal acquired for the object 50 on which the object is to be detected and the model 71 having a surface shape that substantially matches the surface shape of the object 50, and sends it to the signal recording unit 12. When comparing the recorded sub-reflected wave signals with each other, there is a large difference in signal intensity between the reflected wave components from the object 50 and the model 71, but the reflected wave components at the surface portion having the same shape. Subtract the reflected wave component from the surface part of the sub-reflected wave signal from the reflected wave component from the surface part of the main reflected wave signal, and leave the reflected wave component from the detection object While performing the process of canceling the reflected wave component on the surface.

これにより、主反射波信号における検出対象物からの反射波成分にほとんど影響を与えずに、効率よく表面での反射波成分を取除いて、主反射波信号での検出対象物からの反射波成分を相対的に強調できることとなり、物体表面での反射波成分の存在に関わりなく検出対象物６０からの反射波成分を確実に取得でき、画像再構成で検出対象物６０の画像化を精度よく実行可能となり、得られた画像から検出対象物６０を適切に検出することができる。   As a result, the reflected wave component from the detection target in the main reflected wave signal is efficiently removed without affecting the reflected wave component from the detected object in the main reflected wave signal. The components can be relatively emphasized, the reflected wave component from the detection target 60 can be reliably acquired regardless of the presence of the reflected wave component on the object surface, and the imaging of the detection target 60 can be accurately performed by image reconstruction. The detection object 60 can be appropriately detected from the obtained image.

ここで、表面形状を一致させた物体５０とモデル７１を用いて、物体５０表面部の反射波成分を打消す処理を適用した場合の、ノイズ低減効果の例を画像化して示す。物体５０とみなす胸部ファントム（ただし検出対象物は含まない）と、このファントムと表面が同一形状となる、石膏で製作したモデル７１をそれぞれ用意し、物体５０とモデル７１についてそれぞれ反射波信号を取得した。まず、物体５０としてのファントムについて各測定方向ごとに得た反射波信号を、全ての測定方向分を一つの表示にまとめて画像化した信号強度図を、図１１（Ａ）に示す。また、石膏製のモデル７１について各測定方向ごとに得た反射波信号を、全ての測定方向分を一つの表示にまとめて画像化した信号強度図を、図１１（Ｂ）に示す。   Here, an example of the noise reduction effect in the case of applying the processing of canceling the reflected wave component on the surface portion of the object 50 using the object 50 and the model 71 having the same surface shape is shown as an image. A chest phantom regarded as the object 50 (but not including the detection target) and a model 71 made of gypsum having the same shape as the surface of the phantom are prepared, and a reflected wave signal is acquired for each of the object 50 and the model 71. did. First, FIG. 11A shows a signal intensity diagram in which the reflected wave signals obtained for each measurement direction for the phantom as the object 50 are imaged by combining all measurement directions into one display. Further, FIG. 11B shows a signal intensity diagram in which the reflected wave signals obtained for each measurement direction of the model 71 made of gypsum are imaged by combining all the measurement directions into one display.

そして、物体５０とモデル７１の各反射波信号を用いて、物体５０の反射波信号における表面部の反射波成分を打消す処理を、各測定方向ごとに行って得られた新たな反射波信号を、全ての測定方向分を一つの表示にまとめて画像化した信号強度図を、図１２に示す。なお、前記各図の縦軸（左）は物体（又はモデル）に対する測定方向と対応するアンテナの角度位置［ｄｅｇ．］、横軸は計測時間［ｎｓ］で、明暗（右）が反射波信号のピークの信号レベル［Ｖ］、すなわちノイズ成分の大小を示す（明るいほど大）。   Then, using each reflected wave signal of the object 50 and the model 71, a new reflected wave signal obtained by performing processing for canceling the reflected wave component of the surface portion in the reflected wave signal of the object 50 for each measurement direction. FIG. 12 shows a signal intensity diagram in which all the measurement directions are imaged together in one display. In each figure, the vertical axis (left) represents the antenna angular position corresponding to the measurement direction with respect to the object (or model) [deg. ], The horizontal axis is the measurement time [ns], and the brightness (right) indicates the signal level [V] of the peak of the reflected wave signal, that is, the magnitude of the noise component (the brighter the greater).

図１１及び図１２から、単に反射波信号を画像化したものより、二つの反射波信号を用いて物体表面部の反射波成分を打消す処理を行ったものの方が、ノイズ分である表面部の反射波成分を表すピーク（明部）の信号レベル及びその周辺部の信号レベルが、図中の右側の信号レベルを示す明暗遷移帯の強度表示値に見られるように小さくなっており、表面部の反射波成分が画像中に現れにくくなる分、検出対象物が存在する場合にはこれを画像中でより明確に示せることがわかる。   From FIG. 11 and FIG. 12, the surface portion that is the noise component is the one that has been subjected to the process of canceling the reflected wave component of the object surface portion using the two reflected wave signals, rather than just the reflected wave signal imaged. The signal level of the peak (bright part) representing the reflected wave component of the signal and the signal level of the periphery thereof are small as seen in the intensity display value of the light-dark transition band indicating the signal level on the right side of the figure. It can be seen that when the detection target is present, the reflected wave component of the portion is less likely to appear in the image, and this can be shown more clearly in the image.

さらに、同様に表面形状を一致させた物体５０とモデル７１を用いて、物体５０表面部の反射波成分を打消す処理を適用した場合で、石膏に代えて寒天で製作したモデル７１を使用した条件での、ノイズ低減効果の例を画像化して示す。前記同様、物体５０としてのファントムについて各測定方向ごとに得た反射波信号を、全ての測定方向分を一つの表示にまとめて画像化した信号強度図を、図１３（Ａ）に示す。また、ファントムと表面が同一形状の寒天製のモデル７１について各測定方向ごとに得た反射波信号を、全ての測定方向分を一つの表示にまとめて画像化した信号強度図を、図１３（Ｂ）に示す。   Furthermore, in the case where the processing for canceling the reflected wave component on the surface of the object 50 is applied using the object 50 and the model 71 having the same surface shape, the model 71 made of agar instead of gypsum was used. An example of the noise reduction effect under the condition is shown as an image. Similarly to the above, FIG. 13A shows a signal intensity diagram in which the reflected wave signals obtained for each measurement direction with respect to the phantom as the object 50 are imaged by combining all the measurement directions into one display. Further, FIG. 13 shows a signal intensity diagram in which the reflected wave signals obtained for each measurement direction with respect to the agar model 71 having the same shape as the phantom and the surface are imaged by combining all the measurement directions into one display. Shown in B).

そして、物体５０とモデル７１の各反射波信号を用いて、物体５０の反射波信号における表面部の反射波成分を打消す処理を、各測定方向ごとに行って得られた新たな反射波信号を、全ての測定方向分を一つの表示にまとめて画像化した信号強度図を、図１４に示す。この寒天の場合も、前記各図の縦軸（左）は物体（又はモデル）に対する測定方向と対応するアンテナの角度位置［ｄｅｇ．］、横軸は計測時間［ｎｓ］で、明暗（右）が反射波信号のピークの信号レベル［Ｖ］を示す。   Then, using each reflected wave signal of the object 50 and the model 71, a new reflected wave signal obtained by performing processing for canceling the reflected wave component of the surface portion in the reflected wave signal of the object 50 for each measurement direction. FIG. 14 shows a signal intensity diagram in which all the measurement directions are imaged together in one display. Also in the case of this agar, the vertical axis (left) of each figure is the angular position of the antenna corresponding to the measurement direction with respect to the object (or model) [deg. ], The horizontal axis is the measurement time [ns], and light and dark (right) indicates the signal level [V] of the peak of the reflected wave signal.

図１３及び図１４から、モデルの媒質が異なる場合でも、二つの反射波信号を用いて物体表面部の反射波成分を打消す処理を行えば、ノイズ分である表面部の反射波成分を表すピーク（明部）の信号レベル及びその周辺部の信号レベルが、図中の右側の信号レベルを示す明暗遷移帯の強度表示値に見られるように小さくなっており、表面部の反射波成分が画像中に現れにくくなる効果を確実に得ていることがわかる。   From FIG. 13 and FIG. 14, even when the medium of the model is different, the reflected wave component of the surface portion that is a noise component is represented by performing processing to cancel the reflected wave component of the object surface portion using two reflected wave signals. The signal level of the peak (bright part) and the signal level of its peripheral part are small as seen in the intensity display value of the light-dark transition band indicating the signal level on the right side in the figure, and the reflected wave component of the surface part is It turns out that the effect which becomes difficult to appear in an image is acquired reliably.

続いて、前記物体５０として、腫瘍を模した異物（金属球）を内蔵した胸部ファントムを用いると共に、同じ胸部ファントムで異物を内蔵しないものをモデル７１として用いて、物体５０表面部の反射波成分を打消す処理を適用した場合の、ノイズ低減効果の例を画像化して示す。物体５０としての胸部ファントムには、中央表面から約５ｍｍの深さ位置に金属球が内蔵されている。この物体５０とモデル７１についてそれぞれ反射波信号を取得し、これら二つの反射波信号を用いて、物体５０をなすファントムの反射波信号における表面部の反射波成分を打消す処理を、各測定方向ごとに行って得られた新たな反射波信号を、全ての測定方向分を一つの表示にまとめて画像化した信号強度図を、図１５に示す。   Subsequently, as the object 50, a chest phantom containing a foreign body (metal sphere) imitating a tumor is used, and the same chest phantom that does not contain a foreign substance is used as a model 71, and the reflected wave component on the surface of the object 50 is used. An example of the noise reduction effect in the case of applying the process of canceling out is shown as an image. The chest phantom as the object 50 includes a metal sphere at a depth of about 5 mm from the center surface. A reflected wave signal is acquired for each of the object 50 and the model 71, and processing for canceling the reflected wave component of the surface portion in the reflected wave signal of the phantom that forms the object 50 is performed in each measurement direction using these two reflected wave signals. FIG. 15 shows a signal intensity diagram obtained by imaging a new reflected wave signal obtained by performing the measurement for each measurement direction in a single display.

また、比較のために、モデル７１をなすファントムの代りに、物体５０をなすファントムとは異なる形状の別のファントムを用いて、前記同様に物体５０と異形状のファントムとについてそれぞれ反射波信号を取得し、物体５０をなすファントムの反射波信号における表面部の反射波成分を打消す処理を行って得られた新たな反射波信号を、前記同様に全ての測定方向分を一つの表示にまとめて画像化したものを、図１６に示す。ここで、前記各図の縦軸（左）は物体（又はモデル）に対する測定方向と対応するアンテナの角度位置［ｄｅｇ．］、横軸は計測時間［ｎｓ］で、明暗（右）が反射波信号のピークの信号レベル［Ｖ］、すなわち検出対象物の存在確度又はノイズ成分の、大小を示す（明るいほど大）。   For comparison, instead of the phantom forming the model 71, another phantom having a shape different from the phantom forming the object 50 is used, and the reflected wave signals are respectively obtained for the object 50 and the phantom having a different shape as described above. A new reflected wave signal obtained by performing processing for canceling the reflected wave component of the surface portion in the reflected wave signal of the phantom forming the object 50 is combined into a single display in the same manner as described above. FIG. 16 shows an image obtained by imaging. Here, the vertical axis (left) in each figure represents the angular position of the antenna corresponding to the measurement direction with respect to the object (or model) [deg. ], The horizontal axis is the measurement time [ns], and light and dark (right) indicate the signal level [V] of the peak of the reflected wave signal, that is, the existence accuracy of the detection target or the magnitude of the noise component (the brighter the greater).

図１５及び図１６から、モデル７１として物体５０と同じ表面形状のファントムを用いた場合の結果の方が、物体とは異なる形状のファントムを用いた場合の結果に比べて、ノイズ分である表面部の反射波成分を表すピーク（明部）の信号レベル及びその周辺部の信号レベルが、各図中の右側の信号レベルを示す明暗遷移帯の強度表示値に見られるように小さくなっていることに加え、画像中の異物部分を示す０．７〜０．８ｎｓの時間領域における反射波成分において明らかな明部が表示されており、表面部の反射波成分が画像中に現れにくくなることと合わせて、検出対象物を画像中でより明確に示せることがわかる。   From FIG. 15 and FIG. 16, the surface in which the phantom having the same surface shape as the object 50 is used as the model 71 is a noise component compared to the result in the case of using a phantom having a shape different from that of the object. The signal level of the peak (bright part) representing the reflected wave component of the part and the signal level of the peripheral part thereof are small as seen in the intensity display value of the light-dark transition band indicating the signal level on the right side in each figure. In addition, a clear bright portion is displayed in the reflected wave component in the time domain of 0.7 to 0.8 ns indicating the foreign matter portion in the image, and the reflected wave component on the surface portion is less likely to appear in the image. It can be seen that the detection object can be shown more clearly in the image.

（他の実施形態）
前記第１の実施形態に係るマイクロ波イメージングシステムにおいては、カバー８０を被せた物体５０についての主反射波信号と、カバー８０を被せたモデル７０についての副反射波信号とを用い、信号解析手段１３で主反射波信号における表面部からの反射波成分を、副反射波信号における表面部からの反射波成分で打消すことで、画像再構成の画像において表面部からの反射波成分によるノイズ分を減らし、検出対象物６０が相対的に明確化される状態を得る構成としているが、この他、モデルを用いず、対象物の検出を行おうとする物体表面と略同じ形状に形成された誘電体製カバーで、且つその厚さを、カバー中での超短パルスの照射波及び反射波における実効波長の１／４に相当する寸法としたものを、物体５０に被せて、パルス送受信手段１１により各測定方向ごとの反射波信号を得、この反射波信号をパルス送受信手段１１が全ての測定方向について出力するまで、各測定方向ごとの反射波信号を信号記録手段２２でそのまま記録し、全ての測定方向での反射波信号が得られたら信号記録手段２２が反射波信号のデータをまとめて画像再構成手段１５に提供し、画像再構成手段１５で合成開口処理を伴う画像再構成を実行し、物体内画像を生成する構成とすることもできる（図１７参照）。 (Other embodiments)
In the microwave imaging system according to the first embodiment, the main reflected wave signal for the object 50 covered with the cover 80 and the sub-reflected wave signal for the model 70 covered with the cover 80 are used to analyze the signal. 13, the reflected wave component from the surface portion in the main reflected wave signal is canceled by the reflected wave component from the surface portion in the sub-reflected wave signal, so that the noise component due to the reflected wave component from the surface portion in the image reconstruction image. In addition to this, a dielectric object formed in a shape substantially the same as the surface of an object to be detected without using a model is used. A body cover having a thickness corresponding to ¼ of the effective wavelength of the irradiation wave and reflected wave of the ultrashort pulse in the cover is placed on the object 50, and the pulse The reflected wave signal for each measurement direction is obtained by the receiving means 11 and the reflected wave signal for each measurement direction is recorded as it is by the signal recording means 22 until the pulse transmission / reception means 11 outputs the reflected wave signal for all measurement directions. When the reflected wave signals in all the measurement directions are obtained, the signal recording unit 22 collectively provides the reflected wave signal data to the image reconstruction unit 15, and the image reconstruction unit 15 performs image reconstruction with synthetic aperture processing. The configuration may be executed to generate an in-object image (see FIG. 17).

この場合、カバー８１をなす誘電体の厚さが、誘電体媒質中での実効波長の１／４に相当する寸法であることから、カバー表面と裏面の間の多重反射に起因する反射波の干渉効果、すなわち、板の表面からの反射波、裏面からの反射波、さらに反射を繰り返す成分の位相差に起因する干渉効果により、反射波の相殺が生じて、物体５０における表面部からの反射波成分がキャンセルされることとなる。こうして、このマイクロ波イメージングシステム２では、モデルを用いて打消し処理用の反射波信号を取得する必要がなくなり、また信号解析手段による表面反射成分の打消し処理も行わずに済むため、信号処理を簡略化でき、システムのコスト低減や処理の高速化が図れる。   In this case, since the thickness of the dielectric forming the cover 81 is a dimension corresponding to ¼ of the effective wavelength in the dielectric medium, the reflected wave caused by multiple reflection between the cover surface and the back surface The interference effect, that is, the reflected wave from the surface of the plate, the reflected wave from the back surface, and the interference effect caused by the phase difference between the components that repeat reflection, cancels the reflected wave, and the reflection from the surface portion of the object 50 The wave component will be cancelled. Thus, in this microwave imaging system 2, it is not necessary to acquire a reflected wave signal for cancellation processing using a model, and it is not necessary to perform cancellation processing of the surface reflection component by the signal analysis means. The system cost can be reduced and the processing speed can be increased.

さらに、このカバー８１を、物体より比誘電率の高い誘電体材料で形成する構成とすることもでき、その場合、誘電体における波長短縮効果により、カバーをなす誘電体中における実効波長が小さくなる関係から、この実効波長に対応するカバーの厚さを小さくすることができ、カバーの小型化及び材料削減が可能となる。   Further, the cover 81 may be formed of a dielectric material having a relative dielectric constant higher than that of the object. In this case, the effective wavelength in the dielectric forming the cover is reduced due to the wavelength shortening effect in the dielectric. From the relationship, the thickness of the cover corresponding to the effective wavelength can be reduced, and the cover can be downsized and the material can be reduced.

例えば、超短パルスの中心周波数を仮に４ＧＨｚとすると、自由空間中における波長は７．５ｃｍとなり、１／４波長は１．８８ｃｍとなるが、カバーをなす誘電体の比誘電率が２．５の場合、この誘電体中の１／４波長は約１．１９ｃｍとなり、この値がカバーの厚さを決定する。カバーの厚さが大きいと、システム全体のサイズが大きくなるだけでなく、カバー材料のコストも増加する。   For example, if the center frequency of the ultrashort pulse is 4 GHz, the wavelength in free space is 7.5 cm and the quarter wavelength is 1.88 cm, but the dielectric constant of the dielectric that forms the cover is 2.5 cm. In this case, the quarter wavelength in the dielectric is about 1.19 cm, and this value determines the thickness of the cover. A large cover thickness not only increases the overall system size, but also increases the cost of the cover material.

こうした点に対応して、カバーとする誘電体材料の誘電率を高くすれば、カバー中における実効波長を短くすることができ、カバーのサイズの小型化及び材料の削減が可能となる。例として、比誘電率が１２の材料を使用したカバーを製作した場合、同じ周波数条件で、カバーをなす誘電体中の１／４波長は約０．５４ｃｍとなり、前記比誘電率２．５の誘電体からなるカバーの場合と比べて、半分以下の厚みを実現できる。   Corresponding to these points, if the dielectric constant of the dielectric material used as the cover is increased, the effective wavelength in the cover can be shortened, and the size of the cover can be reduced and the material can be reduced. For example, when a cover using a material having a relative dielectric constant of 12 is manufactured, a quarter wavelength in the dielectric forming the cover is about 0.54 cm under the same frequency condition, and the relative dielectric constant of 2.5 Compared to the case of a cover made of a dielectric material, a thickness of half or less can be realized.

なお、前記各実施形態に係るマイクロ波イメージングシステムにおいては、物体５０を胸部組織、検出対象物６０を腫瘍として、乳がん検出に適用する例を挙げているが、これ以外にも生体におけるほぼ均一な誘電率の組織内に誘電率の異なるものが存在し得る状況で、この誘電率の異なる部分を、画像を利用して検出する用途に適用でき、生体の場合は乳がんの他に脳血栓、脳腫瘍等の検出にも適用できる。なお、こうした生体の場合に限られず、マイクロ波帯域で略一定の誘電率となる均質な物体内に誘電率が異なる異物が存在するか存在が予想される場合に、物体内の画像からこの異物を識別する用途にも適用することもできる。この場合、超短パルスの周波数成分の周波数帯域は、物体や異物の誘電率に対応する値として、物体内画像に異物のイメージが明瞭に現れるようにするのが望ましい。   In the microwave imaging system according to each of the above embodiments, the example is applied to breast cancer detection using the object 50 as a breast tissue and the detection target 60 as a tumor. In a situation where different dielectric constants can exist in tissues with a dielectric constant, this part with different dielectric constants can be applied to applications that use images to detect brain thrombus, brain tumor, etc. in addition to breast cancer It can also be applied to detection. It should be noted that the present invention is not limited to such a living body, and when a foreign object having a different dielectric constant exists or is expected to exist in a homogeneous object having a substantially constant dielectric constant in the microwave band, the foreign object is detected from an image in the object. It can also be applied to the purpose of identifying In this case, it is desirable that the frequency band of the frequency component of the ultrashort pulse is a value corresponding to the dielectric constant of the object or foreign object so that the image of the foreign object appears clearly in the in-object image.

本発明のマイクロ波イメージングシステムで、対象物の検出を行おうとする物体とそのモデルとについての各反射波信号を用いて物体表面での反射波成分を打消す処理を実行し、画像再構成により得られた画像における検出対象物の表示状態について評価した。   In the microwave imaging system of the present invention, processing for canceling the reflected wave component on the surface of the object using each reflected wave signal for the object to be detected and its model is executed, and image reconstruction is performed. The display state of the detection object in the obtained image was evaluated.

なお、物体は、非球体の人体胸部を模したファントム（模擬体）であり、ファントム内の検出対象物としての腫瘍に相当するφ０．６〜０．９ｃｍの大きさとなる金属球（異物）以外の部分の誘電率εr＝１０〜２０となっている。腫瘍を模した異物の大きさと配置の組合せは、大きさφ０．９ｃｍの異物をファントム上部中心位置から下方に１ｃｍ下がった内部位置に配置する第一例、大きさφ０．９ｃｍの異物をファントム上部中心位置から下方に１．５ｃｍ下がった内部位置に配置する第二例、及び、大きさφ０．６ｃｍの異物をファントム上部中心位置から下方に０．５ｃｍ下がった内部位置に配設する第三例、の計三通りとする。 Note that the object is a phantom (simulated body) that imitates a non-spherical human chest, and is other than a metal sphere (foreign material) having a size of φ0.6 to 0.9 cm corresponding to a tumor as a detection target in the phantom. The dielectric constant ε r of the portion is 10-20. The combination of the size and arrangement of a foreign body that resembles a tumor is the first example in which a foreign object with a size of φ0.9 cm is placed at an internal position 1 cm downward from the center position of the upper part of the phantom. A second example in which an internal position is lowered 1.5 cm downward from the center position, and a third example in which a foreign matter having a size of φ0.6 cm is disposed at an internal position 0.5 cm downward from the central position of the phantom. , A total of three ways.

また、モデルは、物体をなすファントムと形状は近いが同じではない、人体胸部を模した別のファントムであり、前記三通りの物体に対し同じものを用いる。さらに、物体及びモデルにそれぞれ被せるカバーには、比誘電率が約２〜２．５となる誘電体製のものを用いた。   The model is another phantom that imitates the human chest but is similar in shape to the phantom that forms the object, and the same model is used for the three types of objects. Further, a cover made of a dielectric having a relative dielectric constant of about 2 to 2.5 was used as a cover to be put on the object and the model.

物体内部の画像を取得するにあたっては、前記第１の実施形態に係るマイクロ波イメージングシステムと同様に、物体やモデルに対しアンテナの角度を変えて複数方向から測定を行うために、パルス送受信手段のアンテナは、アンテナ移動機構に取付けられて、カバーを被せた物体又はモデルの近傍に配置され、照射角度を少しずつ変えながら、カバーを被せた物体又はモデルに超短パルスを照射し、各測定角度ごとに物体や検出対象物等からの反射波を測定するようにした。   When acquiring an image inside an object, as in the microwave imaging system according to the first embodiment, in order to perform measurement from multiple directions by changing the angle of the antenna with respect to the object or model, The antenna is attached to the antenna moving mechanism and is placed in the vicinity of the covered object or model. While changing the irradiation angle little by little, the covered object or model is irradiated with ultrashort pulses, and each measurement angle is measured. Every time, the reflected wave from the object or the detection object is measured.

物体又はモデルに向けられた各アンテナはアンテナ移動機構に取付けられて、物体又はモデルの周囲を真横（０°）から反対側（１８０°）まで物体又はモデルの真上を通る経路上で５°ずつ移動して、物体又はモデルに対するパルス照射方向を変えつつ、合計３７箇所で超短パルスを物体又はモデルに向けて照射すると共に反射波を受信することとなる。   Each antenna directed to an object or model is attached to an antenna moving mechanism and is 5 ° on a path that passes directly from the side (0 °) to the opposite side (180 °) of the object or model directly above the object or model. While moving each time, the pulse irradiation direction on the object or model is changed, and the ultrashort pulse is irradiated toward the object or model at a total of 37 locations and the reflected wave is received.

パルス発生器で生成される超短パルスは、パルス幅が６５ｐｓ、振幅が８Ｖである。この超短パルスが、ビバルディアンテナとして形成された照射アンテナから照射される。
物体や検出対象物からの反射波は、照射アンテナと同形状の受信アンテナで受信され、前記信号入出力部としてのサンプリングスコープで波形を確認可能としつつ反射波信号が出力される。 The ultrashort pulse generated by the pulse generator has a pulse width of 65 ps and an amplitude of 8V. This ultrashort pulse is irradiated from an irradiation antenna formed as a Vivaldi antenna.
The reflected wave from the object or the detection target is received by the receiving antenna having the same shape as the irradiation antenna, and the reflected wave signal is output while the waveform can be confirmed by the sampling scope as the signal input / output unit.

物体の前記三通りの各異物配置の全ての場合、及び、モデルの場合も、静止環境としてファントムが静止した状況下で測定され、その測定時間は３２ミリ秒となっている。各場合に共通する、パルス発生器で生じたパルス出力波形と、照射アンテナからの実際の出力波形を、図１８（Ａ）、（Ｂ）に示す。   In all cases of the three kinds of foreign object arrangements of the object and in the case of the model, the measurement is performed under the condition that the phantom is stationary as a stationary environment, and the measurement time is 32 milliseconds. FIGS. 18A and 18B show the pulse output waveform generated by the pulse generator and the actual output waveform from the irradiation antenna, which are common in each case.

まず、カバーを被せたモデルについて、パルス送受信手段により得られた各測定方向ごとの反射波信号（図６参照）が、信号記録手段に入力され、副反射波信号として信号記録手段に記録される。
モデルについて、各測定方向ごとの副反射波信号が全て得られた後、モデルに代って物体に対しての測定が実行される。この実施例１の場合、カバーを被せた物体について、パルス送受信手段により得られた各測定方向ごとの反射波信号（図５参照）が、モデルの場合と同様、信号記録手段に入力され、主反射波信号として信号記録手段に記録される。 First, with respect to the model with the cover, the reflected wave signal (see FIG. 6) for each measurement direction obtained by the pulse transmitting / receiving means is input to the signal recording means and recorded as a sub-reflected wave signal on the signal recording means. .
After all the sub-reflected wave signals for each measurement direction are obtained for the model, measurement on the object is executed instead of the model. In the case of the first embodiment, the reflected wave signal (see FIG. 5) obtained by the pulse transmission / reception means for the object covered with the cover is input to the signal recording means, as in the case of the model, It is recorded in the signal recording means as a reflected wave signal.

各測定方向ごとの主反射波信号が全て得られたら、信号解析手段は、各測定方向ごとの主反射波信号と、この主反射波信号に対応する測定方向の副反射波信号を、信号記録手段からそれぞれ読出して、主反射波信号における表面部の反射波成分を打消す処理を実行し、表面部での反射波成分が打消された主反射波信号を、新たな反射波信号とする。この新たな反射波信号（図７参照）が全ての測定方向について得られたら、これらを用いて画像再構成手段が合成開口処理を伴う画像再構成を実行し、物体内画像が生成される。   When all the main reflected wave signals for each measuring direction are obtained, the signal analyzing means records the main reflected wave signal for each measuring direction and the sub reflected wave signal for the measuring direction corresponding to the main reflected wave signal. Each read out from the means, processing for canceling the reflected wave component of the surface portion in the main reflected wave signal is executed, and the main reflected wave signal in which the reflected wave component at the surface portion is canceled is set as a new reflected wave signal. When this new reflected wave signal (see FIG. 7) is obtained for all measurement directions, the image reconstruction means performs image reconstruction with synthetic aperture processing using these signals, and an in-object image is generated.

このように、物体の前記三通りの異物配置例について、胸部を模したカバーを被せた物体とモデルの各ファントムを用いて、主反射波信号と副反射波信号を得て、物体表面部の反射波成分を打消す処理を適用し、最終的に反射波信号の画像再構成を経て取得した物体内画像を、第一例の場合を図１９に、第二例の場合を図２０に、第三例の場合を図２１にそれぞれ示す。
ここで、各図の縦軸（左）は物体頂点からの縦方向距離［ｍ］、横軸は物体の頂点直下からの横方向距離［ｍ］で、明暗（右）が反射波信号の強さ［任意単位（a.u.）］、すなわち検出対象物の存在確度を示す（明るいほど大）。なお、画像中の白線は物体の表面位置を示す線である。 As described above, for the three examples of the foreign object arrangement of the object, the main reflected wave signal and the sub reflected wave signal are obtained by using the object covered with the chest and the model phantom, and the object surface portion is obtained. Applying the process of canceling the reflected wave component, the in-object image finally obtained through image reconstruction of the reflected wave signal, the case of the first example in FIG. 19, the case of the second example in FIG. The case of the third example is shown in FIG.
Here, the vertical axis (left) in each figure is the vertical distance [m] from the object vertex, the horizontal axis is the horizontal distance [m] from directly below the object vertex, and the light and dark (right) is the intensity of the reflected wave signal. [Arbitrary unit (au)], that is, the existence accuracy of the detection target (the brighter the greater). The white line in the image is a line indicating the surface position of the object.

前記各図から、画像再構成後のいずれの物体内画像も、信号レベルの高い、検出対象物と見なせる周囲と明らかに異なるイメージ部分がごく限られた位置に集中的に生成されており、画像から検出対象物を特定することが可能となっている。   From each of the above figures, all the in-object images after the image reconstruction are intensively generated at very limited positions where the image portion having a high signal level and clearly different from the surroundings that can be regarded as the detection target is obtained. From this, it is possible to specify the detection object.

以上から、本発明のマイクロ波イメージングシステムで、対象物の検出を行おうとする物体についての主反射波信号と、物体に近い誘電率の材質からなるモデルについての副反射波信号とをそれぞれ取得し、各反射波信号で同様に現れる物体表面での反射波成分を、主反射波信号から副反射波信号を減算し打消すことで、主反射波信号から物体表面での反射波成分が取除かれる一方で、検出対象物からの反射波成分は残すことができ、こうして残った検出対象物からの反射波成分を画像再構成に利用して、物体内画像に物体表面での反射波成分の影響を受けない明確な検出対象物のイメージを生成でき、物体内画像から検出対象物を確実に検出可能であることがわかる。   From the above, in the microwave imaging system of the present invention, the main reflected wave signal for the object whose object is to be detected and the sub reflected wave signal for the model made of a material having a dielectric constant close to the object are obtained. By subtracting the sub-reflected wave signal from the main reflected wave signal and canceling the reflected wave component that appears in the same way in each reflected wave signal, the reflected wave component on the object surface is removed from the main reflected wave signal. On the other hand, the reflected wave component from the detection target can be left, and the reflected wave component from the detection target remaining in this way is used for image reconstruction, and the reflected wave component on the object surface is reflected in the in-object image. It can be seen that a clear image of the detection object that is not affected can be generated, and the detection object can be reliably detected from the in-object image.

続いて、本発明のマイクロ波イメージングシステムを用いて、対象物の検出を行おうとする物体とそのモデルとについての各反射波信号を測定する際の、カバーが物体又はモデルに相対的に押付けられる度合を変化させて測定を行い、物体表面での反射波成分を打消す処理を経て反射波信号を得、この反射波信号を画像化した画像における、カバー押付け状態の影響について評価した。
なお、物体は、非球体の人体胸部を模したファントム（模擬体）であり、ファントム内に検出対象物が存在しないものを用いる。また、モデルは、物体をなすファントムと形状は近いが同じではない、人体胸部を模した別のファントムである。 Subsequently, using the microwave imaging system of the present invention, the cover is pressed relatively to the object or model when measuring each reflected wave signal for the object to be detected and its model. Measurement was performed at various degrees, and a reflected wave signal was obtained through a process of canceling the reflected wave component on the object surface. The effect of the cover pressing state on the image obtained by imaging the reflected wave signal was evaluated.
The object is a phantom (simulated body) imitating a non-spherical human chest, and an object having no detection target in the phantom is used. The model is another phantom that imitates the human chest but is similar in shape to the phantom that forms the object.

さらに、物体及びモデルにそれぞれ被せるカバーには、比誘電率が約２〜２．５となる誘電体製のものを用い、物体やモデルのある領域より外側へ略鍔状に張出す部分を設け、この張出し部分を物体やモデルを支持する支持台に対し全周にわたり均一に力を加えるようにして固定状態とする。物体やモデルにカバーを被せるにあたり、支持台の物体やモデルを載せる部分の高さを調整することで、カバーが物体やモデルに相対的に押付けられる状態を変えられる仕組みとした。   Furthermore, the cover that covers each of the object and the model is made of a dielectric that has a relative dielectric constant of about 2 to 2.5, and a portion that protrudes in a generally bowl shape from the area where the object or model is located is provided. The overhanging portion is fixed in such a manner that a force is uniformly applied over the entire circumference to the support base that supports the object or the model. When the cover is placed on the object or model, the height of the part of the support base on which the object or model is placed is adjusted to change the state in which the cover is pressed against the object or model.

画像を取得するにあたっては、前記第１の実施形態に係るマイクロ波イメージングシステムと同様に、パルス送受信手段のアンテナは、アンテナ移動機構に取付けられて、カバーを被せた物体又はモデルの近傍に配置され、照射角度を少しずつ変えながら、カバーを被せた物体又はモデルに超短パルスを照射し、各測定角度ごとに物体や検出対象物等からの反射波を測定するようにした。   When acquiring an image, similarly to the microwave imaging system according to the first embodiment, the antenna of the pulse transmitting / receiving means is attached to the antenna moving mechanism and is arranged in the vicinity of the object or model covered with the cover. While changing the irradiation angle little by little, the object or model covered with the cover was irradiated with an ultrashort pulse, and the reflected wave from the object, the detection object, etc. was measured at each measurement angle.

測定では、物体としてのファントムと、モデルとしての別のファントムの各表面に同一のカバーを被せ、カバーと各ファントムの位置関係を四通りに設定した各条件で、各ファントムについてそれぞれ反射波信号を取得した。
まず、カバーを被せたモデルについて、パルス送受信手段により得られた各測定方向ごとの反射波信号が、信号記録手段に入力され、副反射波信号として信号記録手段に記録される。 In the measurement, the same cover is put on each surface of the phantom as an object and another phantom as a model, and the reflected wave signal is output for each phantom under each condition where the positional relationship between the cover and each phantom is set in four ways. I got it.
First, for a model with a cover, the reflected wave signal for each measurement direction obtained by the pulse transmission / reception means is input to the signal recording means and recorded as a sub-reflected wave signal in the signal recording means.

モデルについて、各測定方向ごとの副反射波信号が全て得られた後、モデルに代って物体に対しての測定が実行される。この実施例２の場合も、カバーを被せた物体について、パルス送受信手段により得られた各測定方向ごとの反射波信号が、モデルの場合と同様、信号記録手段に入力され、主反射波信号として信号記録手段に記録される。   After all the sub-reflected wave signals for each measurement direction are obtained for the model, measurement on the object is executed instead of the model. Also in the case of the second embodiment, the reflected wave signal for each measurement direction obtained by the pulse transmission / reception unit for the object covered with the cover is input to the signal recording unit as in the case of the model, and is used as the main reflected wave signal. Recorded in the signal recording means.

各測定方向ごとの主反射波信号が全て得られたら、信号解析手段は、各測定方向ごとの主反射波信号と、この主反射波信号に対応する測定方向の副反射波信号を、信号記録手段からそれぞれ読出して、主反射波信号における表面部の反射波成分を打消す処理を実行し、表面部での反射波成分が打消された主反射波信号を、新たな反射波信号とする。この反射波信号が全ての測定方向について得られたら、これら各測定方向ごとの新たな反射波信号を、全ての測定方向分を一つの表示にまとめて画像化した。   When all the main reflected wave signals for each measuring direction are obtained, the signal analyzing means records the main reflected wave signal for each measuring direction and the sub reflected wave signal for the measuring direction corresponding to the main reflected wave signal. Each read out from the means, processing for canceling the reflected wave component of the surface portion in the main reflected wave signal is executed, and the main reflected wave signal in which the reflected wave component at the surface portion is canceled is set as a new reflected wave signal. When this reflected wave signal was obtained for all measurement directions, a new reflected wave signal for each measurement direction was imaged by combining all the measurement directions into one display.

物体又はモデルとしての各ファントムと、カバーとの位置関係として、カバーを支持台に適切に固定せず、カバーと物体又はモデルとが完全に密着せず、カバーと物体又はモデルとの間に隙間が生じていると考えられる第一例、支持台の各ファントムを載せる部分の高さを３ｍｍとし、カバーを支持台に適切に固定した第二例、支持台の各ファントムを載せる部分の高さを５ｍｍとし、カバーを支持台に適切に固定した第三例、及び、支持台の各ファントムを載せる部分の高さを８ｍｍとし、カバーを支持台に適切に固定した第四例、の計四通りについて、各ファントムについてそれぞれ反射波信号を取得し、物体をなすファントムの反射波信号における表面部の反射波成分を打消す処理を、各測定方向ごとに行って得られた新たな反射波信号を、全ての測定方向分を一つの表示にまとめて画像化した信号強度図を、図２２〜図２５に示す。
ここで、前記各図の縦軸（左）は物体（又はモデル）に対する測定方向と対応するアンテナの角度位置［ｄｅｇ．］、横軸は計測時間［ｎｓ］で、明暗（右）が反射波信号のピークの信号レベル［Ｖ］、すなわちノイズ成分の大小を示す（明るいほど大）。 As the positional relationship between each phantom as an object or model and the cover, the cover is not properly fixed to the support base, the cover and the object or model are not completely adhered, and there is a gap between the cover and the object or model. The first example is considered to have occurred, the height of the part of the support base where each phantom is placed is 3 mm, the second example where the cover is appropriately fixed to the support base, the height of the part of the support base where each phantom is placed 4 mm, a third example in which the cover is appropriately fixed to the support base, and a fourth example in which the height of the part on which each phantom is placed is 8 mm and the cover is appropriately fixed to the support base. For each street, a reflected wave signal is obtained for each phantom, and a new reflected wave signal obtained by performing the processing for canceling the reflected wave component of the surface portion in the reflected wave signal of the phantom constituting the object for each measurement direction. The all one signal strength diagram imaged together on a display of the measurement direction component, shown in FIGS. 22 to 25.
Here, the vertical axis (left) in each figure represents the angular position of the antenna corresponding to the measurement direction with respect to the object (or model) [deg. ], The horizontal axis is the measurement time [ns], and the brightness (right) indicates the signal level [V] of the peak of the reflected wave signal, that is, the magnitude of the noise component (larger as it is brighter).

図２２及び図２３によれば、カバーと物体又はモデルとが完全に密着してないとみなせる第一例に比べ、支持台のファントム載置部分の高さを３ｍｍとした第二例の結果の方が、ノイズ分である表面部の反射波成分を表すピーク（明部）の信号レベル及びその周辺部の信号レベルが、各図中の右側の信号レベルを示す明暗遷移帯の強度表示値に見られるように小さくなっている。具体的には、図２２で示される第一例のピークの最大レベルが５．８×１０-3であるのに対し、図２３で示される第二例では２．４×１０-3となっており、カバーと物体又はモデルとの密着で、表面部での不要な反射波成分の発生が抑えられ、打消しの処理を経た反射波信号においてもその好影響があらわれていることがわかる。 According to FIG. 22 and FIG. 23, the result of the second example in which the height of the phantom mounting portion of the support base is 3 mm as compared with the first example in which the cover and the object or the model can be regarded as not being completely adhered to each other. On the other hand, the signal level of the peak (bright part) representing the reflected wave component of the surface part, which is a noise component, and the signal level of the peripheral part thereof become the intensity display value of the light-dark transition band indicating the signal level on the right side in each figure. It is small so that it can be seen. Specifically, the maximum level of the peak in the first example shown in FIG. 22 is 5.8 × 10 −3 , whereas in the second example shown in FIG. 23, it becomes 2.4 × 10 −3. It can be seen that the close contact between the cover and the object or the model suppresses the generation of unnecessary reflected wave components on the surface portion, and the reflected wave signal that has been subjected to the cancellation process also has a positive effect.

一方、図２４の第三例や図２５の第四例に見られるように、支持台のファントム載置部分の高さを５ｍｍ、８ｍｍとさらに大きくしていくと、前記３ｍｍの場合（第二例）と比べて、ノイズ成分である表面部の反射波成分を表すピーク（明部）の信号レベル及びその周辺部の信号レベルが大きくなっている。具体的には、第三例のピークの最大レベルが２．７×１０-3、また第四例では４．９×１０-3となっている。これは、ファントムに対しカバーを押さえ過ぎる状態となった場合、ファントムやカバーに加わる力でこれらの間にわずかな隙間をもたらすような形状の変化が起り、誘電率の異なる二つの物質の境界面が新たに発生した影響により、ノイズの点でかえって悪化する結果となったと考えられる。 On the other hand, as can be seen in the third example of FIG. 24 and the fourth example of FIG. 25, when the height of the phantom mounting portion of the support base is further increased to 5 mm and 8 mm, Compared to the example), the signal level of the peak (bright part) representing the reflected wave component of the surface part, which is a noise component, and the signal level of the peripheral part thereof are higher. Specifically, the maximum peak level of the third example is 2.7 × 10 −3 , and the fourth example is 4.9 × 10 −3 . This is because when the cover is pressed too far against the phantom, the force applied to the phantom or cover causes a change in shape that causes a slight gap between them, and the interface between the two materials with different dielectric constants. It is thought that this resulted in a worsening in terms of noise due to the newly generated effect.

以上から、本発明のマイクロ波イメージングシステムで、カバーを被せた物体についての主反射波信号と、カバーを被せたモデルについての副反射波信号とをそれぞれ取得する際、カバーと物体又はモデルとの位置関係を調整し、カバーや物体等が過剰に変形しない程度に、カバーを相対的に物体又はモデルに向けて押付ける状態を得て、カバーを物体又はモデルに均一に密着させることで、ノイズ成分となる反射波の発生を抑え、主反射波信号から物体表面での反射波成分を打消す処理を経て得られる新たな反射波信号において、検出対象物からの反射波成分へのノイズによる悪影響を抑制して、画像再構成後の物体内画像における検出対象物イメージの明確化に繋げられることがわかる。   From the above, in the microwave imaging system of the present invention, when acquiring the main reflected wave signal for the object covered with the cover and the sub-reflected wave signal for the model covered with the cover, By adjusting the positional relationship and obtaining a state in which the cover is relatively pressed toward the object or model to the extent that the cover or object is not excessively deformed, the cover is evenly adhered to the object or model, thereby reducing noise. In the new reflected wave signal obtained by suppressing the generation of the reflected wave component and canceling the reflected wave component on the object surface from the main reflected wave signal, adverse effects due to noise on the reflected wave component from the detection target It can be understood that the detection object image in the in-object image after the image reconstruction is clarified.

１、２ マイクロ波イメージングシステム
１１ パルス送受信手段
１１ａ 照射アンテナ
１１ｂ 受信アンテナ
１１ｃ パルス発生器
１１ｄ アンテナ移動機構
１１ｅ 信号入出力部
１１ｆ 制御部
１２、２２ 信号記録手段
１３ 信号解析手段
１５ 画像再構成手段
１６ 表示手段
１７ 押え板
１８ 支持台
５０ 物体
６０ 検出対象物
７０、７１ モデル
８０、８１ カバー
８０ａ 張出し部分 DESCRIPTION OF SYMBOLS 1, 2 Microwave imaging system 11 Pulse transmission / reception means 11a Irradiation antenna 11b Reception antenna 11c Pulse generator 11d Antenna moving mechanism 11e Signal input / output part 11f Control part 12, 22 Signal recording means 13 Signal analysis means 15 Image reconstruction means 16 Display Means 17 Presser plate 18 Support base 50 Object 60 Object 70, 71 Model 80, 81 Cover 80a Overhang portion

Claims (7)

周波数成分がマイクロ波帯域に及ぶ超短パルスを、内部に誘電率の異なる検出対象物が存在するか又は存在すると予想される所定の物体に対し複数方向から照射し、複数方向の反射波の測定結果を用いて、合成開口処理を伴う画像再構成を実行し、前記物体内における検出対象物の位置を画像化するマイクロ波イメージングシステムにおいて、
前記物体に対し超短パルスを複数方向から同時に又は順次時間をずらして照射すると共に、各照射方向ごとに物体や検出対象物からの反射波を受信し、反射波の信号を出力するパルス送受信手段と、
前記パルス送受信手段から出力された反射波信号を記録する信号記録手段と、
当該信号記録手段から読出される一の反射波信号と、新たに前記パルス送受信手段から出力されるか、前記信号記録手段から別途読出される、他の反射波信号とを比較解析する信号解析手段とを備え、
前記一の反射波信号が、前記物体表面と略同じ形状に形成された誘電体製のカバーを被せた前記物体について、前記パルス送受信手段で超短パルスを照射して得られる各方向ごとの所定時間にわたる反射波信号である主反射波信号、及び、前記物体の誘電率に近い誘電率となる材料を用いて形成された前記物体のモデルに、前記カバーを被せたものについて、前記パルス送受信手段で超短パルスを照射して得られた各方向の所定時間にわたる反射波信号である副反射波信号、のいずれか一方であり、
前記他の反射波信号が、前記主副の各反射波信号の他方であり、
前記信号解析手段が、前記主反射波信号における表面部からの反射波成分を、前記副反射波信号における表面部からの反射波成分で打消し、検出対象物からの反射波成分が相対的に強調された主反射波信号を画像再構成用の新たな反射波信号とすることを
特徴とするマイクロ波イメージングシステム。 Measures reflected waves in multiple directions by irradiating a predetermined object that has or is expected to have a detection object with a different dielectric constant from multiple directions with an ultra-short pulse whose frequency component covers the microwave band. In the microwave imaging system that performs image reconstruction with synthetic aperture processing using the result and images the position of the detection target in the object,
Pulse transmitting / receiving means for irradiating the object with ultra-short pulses simultaneously or sequentially from a plurality of directions, receiving a reflected wave from the object or a detection target for each irradiation direction, and outputting a reflected wave signal When,
Signal recording means for recording the reflected wave signal output from the pulse transmitting / receiving means;
Signal analysis means for comparing and analyzing one reflected wave signal read from the signal recording means and another reflected wave signal newly output from the pulse transmitting / receiving means or read separately from the signal recording means And
Predetermined in each direction obtained by irradiating an ultrashort pulse with the pulse transmitting / receiving means on the object covered with a dielectric cover formed with the one reflected wave signal having substantially the same shape as the object surface The pulse transmission / reception means for a main reflected wave signal that is a reflected wave signal over time and a model of the object formed using a material having a dielectric constant close to the dielectric constant of the object, with the cover covered Or a sub reflected wave signal that is a reflected wave signal over a predetermined time in each direction obtained by irradiating an ultrashort pulse at
The other reflected wave signal is the other of the main and sub reflected wave signals,
The signal analyzing means cancels the reflected wave component from the surface portion in the main reflected wave signal with the reflected wave component from the surface portion in the sub reflected wave signal, and the reflected wave component from the detection target is relatively A microwave imaging system characterized in that the enhanced main reflected wave signal is used as a new reflected wave signal for image reconstruction. 周波数成分がマイクロ波帯域に及ぶ超短パルスを、内部に誘電率の異なる検出対象物が存在するか又は存在すると予想される所定の物体に対し複数方向から照射し、複数方向の反射波の測定結果を用いて、合成開口処理を伴う画像再構成を実行し、前記物体内における検出対象物の位置を画像化するマイクロ波イメージングシステムにおいて、
前記物体に対し超短パルスを複数方向から同時に又は順次時間をずらして照射すると共に、各照射方向ごとに物体や検出対象物からの反射波を受信し、反射波の信号を出力するパルス送受信手段と、
前記パルス送受信手段から出力された反射波信号を記録する信号記録手段と、
当該信号記録手段から読出される一の反射波信号と、新たに前記パルス送受信手段から出力されるか、前記信号記録手段から別途読出される、他の反射波信号とを比較解析する信号解析手段とを備え、
前記一の反射波信号が、前記物体について、前記パルス送受信手段で超短パルスを照射して得られる各方向ごとの所定時間にわたる反射波信号である主反射波信号、及び、前記物体表面と略同じ形状に形成された表面部を有する誘電体製の前記物体のモデルについて、前記パルス送受信手段で超短パルスを照射して得られた各方向の所定時間にわたる反射波信号である副反射波信号、のいずれか一方であり、
前記他の反射波信号が、前記主副の各反射波信号の他方であり、
前記信号解析手段が、前記主反射波信号における表面部からの反射波成分を、前記副反射波信号における表面部からの反射波成分で打消し、検出対象物からの反射波成分が相対的に強調された主反射波信号を画像再構成用の新たな反射波信号とすることを
特徴とするマイクロ波イメージングシステム。 Measures reflected waves in multiple directions by irradiating a predetermined object that has or is expected to have a detection object with a different dielectric constant from multiple directions with an ultra-short pulse whose frequency component covers the microwave band. In the microwave imaging system that performs image reconstruction with synthetic aperture processing using the result and images the position of the detection target in the object,
Pulse transmitting / receiving means for irradiating the object with ultra-short pulses simultaneously or sequentially from a plurality of directions, receiving a reflected wave from the object or a detection target for each irradiation direction, and outputting a reflected wave signal When,
Signal recording means for recording the reflected wave signal output from the pulse transmitting / receiving means;
Signal analysis means for comparing and analyzing one reflected wave signal read from the signal recording means and another reflected wave signal newly output from the pulse transmitting / receiving means or read separately from the signal recording means And
The one reflected wave signal is a main reflected wave signal that is a reflected wave signal over a predetermined time in each direction obtained by irradiating the object with an ultrashort pulse by the pulse transmitting / receiving means, and substantially the same as the object surface. Subreflected wave signal that is a reflected wave signal over a predetermined time in each direction obtained by irradiating an ultrashort pulse with the pulse transmitting / receiving means for the model of the dielectric object having the surface portion formed in the same shape , Either
The other reflected wave signal is the other of the main and sub reflected wave signals,
The signal analyzing means cancels the reflected wave component from the surface portion in the main reflected wave signal with the reflected wave component from the surface portion in the sub reflected wave signal, and the reflected wave component from the detection target is relatively A microwave imaging system characterized in that the enhanced main reflected wave signal is used as a new reflected wave signal for image reconstruction. 前記請求項１に記載のマイクロ波イメージングシステムにおいて、
前記カバーが、当該カバーをなす誘電体材料中での超短パルスの照射波及び反射波における実効波長の１／４に相当する寸法の厚さとされることを
特徴とするマイクロ波イメージングシステム。 The microwave imaging system of claim 1, wherein
The microwave imaging system, wherein the cover has a thickness corresponding to ¼ of an effective wavelength of an irradiation wave and a reflection wave of an ultrashort pulse in a dielectric material forming the cover. 前記請求項３に記載のマイクロ波イメージングシステムにおいて、
前記カバーが、前記物体より比誘電率の高い誘電体材料で形成されることを
特徴とするマイクロ波イメージングシステム。 The microwave imaging system of claim 3, wherein
The microwave imaging system, wherein the cover is formed of a dielectric material having a relative dielectric constant higher than that of the object. 前記請求項１ないし４のいずれかに記載のマイクロ波イメージングシステムにおいて、
前記信号解析手段が、前記主反射波信号における表面部からの反射波成分を打消す処理として、前記副反射波信号に、副反射波信号の信号レベルに対する主反射波信号の信号レベルの割合を乗じて、規格化を行ったものを、主反射波信号から差引くことを
特徴とするマイクロ波イメージングシステム。 In the microwave imaging system according to any one of claims 1 to 4,
The signal analysis means, as a process of canceling the reflected wave component from the surface portion in the main reflected wave signal, in the sub reflected wave signal, the ratio of the signal level of the main reflected wave signal to the signal level of the sub reflected wave signal A microwave imaging system characterized by subtracting the normalized signal by multiplication from the main reflected wave signal. 周波数成分がマイクロ波帯域に及ぶ超短パルスを、内部に誘電率の異なる検出対象物が存在するか又は存在すると予想される所定の物体に対し複数方向から照射し、複数方向の反射波の測定結果を用いて、合成開口処理を伴う画像再構成を実行し、前記物体内における検出対象物の位置を画像化するマイクロ波イメージング処理方法において、
パルス送受信手段が、前記物体表面と略同じ形状に形成された誘電体製のカバーを被せた前記物体に対し、超短パルスを複数方向から同時に又は順次時間をずらして照射すると共に、各照射方向ごとに反射波を受信して、反射波の信号を主反射波信号として出力し、
また、前記パルス送受信手段が、前記物体の誘電率に近い誘電率となる材料を用いて形成された前記物体のモデルに、前記カバーを被せたものに対し、超短パルスを複数方向から同時に又は順次時間をずらして照射すると共に、各照射方向ごとに反射波を受信して、反射波の信号を副反射波信号として出力し、
信号記録手段が、前記パルス送受信手段から出力される主反射波信号及び／又は副反射波信号を記録し、
信号解析手段が、前記信号記録手段から読出される前記主副の反射波信号のいずれか一方と、新たに前記パルス送受信手段から出力されるか、前記信号記録手段から別途読出される、前記主副の各反射波信号の他方とを比較解析し、前記主反射波信号における表面部からの反射波成分を、前記副反射波信号における表面部からの反射波成分で打消し、検出対象物からの反射波成分が相対的に強調された主反射波信号を画像再構成用の新たな反射波信号として出力することを
特徴とするマイクロ波イメージング処理方法。 Measures reflected waves in multiple directions by irradiating a predetermined object that has or is expected to have a detection object with a different dielectric constant from multiple directions with an ultra-short pulse whose frequency component covers the microwave band. In the microwave imaging processing method of performing image reconstruction with synthetic aperture processing using the result and imaging the position of the detection target in the object,
The pulse transmitting / receiving means irradiates the object covered with a dielectric cover formed in substantially the same shape as the surface of the object with an ultra-short pulse from a plurality of directions simultaneously or sequentially while shifting the time. Each time a reflected wave is received, the reflected wave signal is output as the main reflected wave signal,
In addition, the pulse transmitting / receiving means may simultaneously apply an ultrashort pulse from a plurality of directions to a model of the object formed using a material having a dielectric constant close to the dielectric constant of the object, and cover the cover. Irradiate with a time shift sequentially, receive the reflected wave for each irradiation direction, output the reflected wave signal as a sub-reflected wave signal,
The signal recording means records the main reflected wave signal and / or the sub reflected wave signal output from the pulse transmitting / receiving means,
The signal analyzing means outputs one of the main and sub reflected wave signals read from the signal recording means, and is newly output from the pulse transmitting / receiving means or read separately from the signal recording means. Comparing and analyzing the other of the sub reflected wave signals, the reflected wave component from the surface portion in the main reflected wave signal is canceled out by the reflected wave component from the surface portion in the sub reflected wave signal, and from the detection object A microwave imaging processing method comprising: outputting a main reflected wave signal in which a reflected wave component of the image is relatively emphasized as a new reflected wave signal for image reconstruction. 周波数成分がマイクロ波帯域に及ぶ超短パルスを、内部に誘電率の異なる検出対象物が存在するか又は存在すると予想される所定の物体に対し複数方向から照射し、複数方向の反射波の測定結果を用いて、合成開口処理を伴う画像再構成を実行し、前記物体内における検出対象物の位置を画像化するマイクロ波イメージング処理方法において、
パルス送受信手段が、前記物体に対し、超短パルスを複数方向から同時に又は順次時間をずらして照射すると共に、各照射方向ごとに反射波を受信して、反射波の信号を主反射波信号として出力し、
また、前記パルス送受信手段が、前記物体表面と略同じ形状に形成された表面部を有する誘電体製の前記物体のモデルに対し、超短パルスを複数方向から同時に又は順次時間をずらして照射すると共に、各照射方向ごとに反射波を受信して、反射波の信号を副反射波信号として出力し、
信号記録手段が、前記パルス送受信手段から出力される主反射波信号及び／又は副反射波信号を記録し、
信号解析手段が、前記信号記録手段から読出される前記主副の反射波信号のいずれか一方と、新たに前記パルス送受信手段から出力されるか、前記信号記録手段から別途読出される、前記主副の各反射波信号の他方とを比較解析し、前記主反射波信号における表面部からの反射波成分を、前記副反射波信号における表面部からの反射波成分で打消し、検出対象物からの反射波成分が相対的に強調された主反射波信号を画像再構成用の新たな反射波信号として出力することを
特徴とするマイクロ波イメージング処理方法。 Measures reflected waves in multiple directions by irradiating a predetermined object that has or is expected to have a detection object with a different dielectric constant from multiple directions with an ultra-short pulse whose frequency component covers the microwave band. In the microwave imaging processing method of performing image reconstruction with synthetic aperture processing using the result and imaging the position of the detection target in the object,
The pulse transmitting / receiving means irradiates the object with an ultrashort pulse from a plurality of directions simultaneously or sequentially, receiving a reflected wave in each irradiation direction, and using the reflected wave signal as a main reflected wave signal. Output,
The pulse transmitting / receiving means irradiates a model of the object made of a dielectric having a surface portion formed in substantially the same shape as the surface of the object with ultrashort pulses simultaneously or sequentially from a plurality of directions at different times. In addition, the reflected wave is received for each irradiation direction, and the reflected wave signal is output as a sub-reflected wave signal.
The signal recording means records the main reflected wave signal and / or the sub reflected wave signal output from the pulse transmitting / receiving means,
The signal analyzing means outputs one of the main and sub reflected wave signals read from the signal recording means, and is newly output from the pulse transmitting / receiving means or read separately from the signal recording means. Comparing and analyzing the other of the sub reflected wave signals, the reflected wave component from the surface portion in the main reflected wave signal is canceled out by the reflected wave component from the surface portion in the sub reflected wave signal, and from the detection object A microwave imaging processing method comprising: outputting a main reflected wave signal in which a reflected wave component of the image is relatively emphasized as a new reflected wave signal for image reconstruction.
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