JP2672546B2 - Intracranial blood flow sound processor - Google Patents
Intracranial blood flow sound processorInfo
- Publication number
- JP2672546B2 JP2672546B2 JP63026475A JP2647588A JP2672546B2 JP 2672546 B2 JP2672546 B2 JP 2672546B2 JP 63026475 A JP63026475 A JP 63026475A JP 2647588 A JP2647588 A JP 2647588A JP 2672546 B2 JP2672546 B2 JP 2672546B2
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- JP
- Japan
- Prior art keywords
- blood flow
- flow sound
- intracranial
- sound
- heartbeat
- Prior art date
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Description
【発明の詳細な説明】 ［発明の目的］ （産業上の利用分野） 本発明は、脳動脈瘤や動静脈奇形などの頭蓋内病変部
位により生じる異常血流音を頭蓋外より非侵襲で検出
し、これを解析処理することにより前記病変部位の有無
及び位置推定を可能とする頭蓋内血流音処理装置に関す
る。DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention detects abnormal blood flow sounds caused by intracranial lesions such as cerebral aneurysms and arteriovenous malformations from outside the skull non-invasively. However, the present invention relates to an intracranial blood flow sound processing apparatus that enables the presence / absence and position estimation of the lesion site by analyzing this.
（従来の技術） クモ膜下出血の主因である頭蓋内動脈瘤や動静脈奇形
が異常血流音を発していることは周知のことであり、こ
の異常血流音の検出により頭蓋内動脈瘤や動静脈奇形の
位置推定を頭蓋外より非侵襲で行う手法が報告されてい
る（たとえば、CLINICAL NEUROSCHINCE Vol.3 No.8（19
85）P.P866−867）。この手法は、頭蓋外に配置された
血流音検出手段（ディテクタ）で異常血流音を検出し、
この検出信号を解析処理するようにしたもので、血流音
検出手段としては、第７図に示すもの等が使用される。
即ち、この血流音検出手段６は、有底筒状に形成された
ケース体２内に加速度検出器１を配置し、この加速度検
出器１をスタビライザ５で支持し、加速度検出器１とケ
ース体２の底部との間にバネ３を取り付けることにより
構成され、このバネ３の付勢力に抗して加速度検出器１
を被検体（通常は患者）の頭部４に当接することで、血
流音を検出しようとするものである。(Prior Art) It is well known that intracranial aneurysms and arteriovenous malformations, which are the main causes of subarachnoid hemorrhage, produce abnormal blood flow sounds. By detecting these abnormal blood flow sounds, intracranial aneurysms are detected. A non-invasive method to estimate the location of arteriovenous malformations from the outside of the skull has been reported (eg CLINICAL NEUROSCHINCE Vol.3 No.8 (19
85) P.P866-867). This method detects abnormal blood flow sound with blood flow sound detection means (detector) placed outside the skull,
The detection signal is analyzed, and the blood flow sound detecting means shown in FIG. 7 is used.
That is, in the blood flow sound detecting means 6, the acceleration detector 1 is arranged in a case body 2 formed in a bottomed cylindrical shape, and the acceleration detector 1 is supported by a stabilizer 5 so that the acceleration detector 1 and the case are supported. The acceleration detector 1 is constructed by attaching a spring 3 between the bottom of the body 2 and the urging force of the spring 3.
The blood flow sound is to be detected by contacting the head part 4 of the subject (usually a patient) with.
このような血流音検出手段６を被検体の頭部４に複数
個取り付け、それらの検出結果を処理して分析すること
で、頭蓋内病変部位の有無及び位置推定を行っている。By attaching a plurality of such blood flow sound detecting means 6 to the head 4 of the subject and processing and analyzing the detection results, the presence / absence and position of the intracranial lesion site are estimated.
（発明が解決しようとする課題） しかしながら、血流音は非常に小さく、血流音検出手
段には血流音のみでなく他の雑音、例えば呼吸音や唾を
吸い込む音などが侵入してしまい、このため血流音検出
手段の検出信号を解析しても頭蓋内病変部位の有無及び
位置推定が容易に行えないという問題が生じていた。(Problems to be Solved by the Invention) However, the blood flow sound is very small, and not only the blood flow sound but also other noises such as breathing sounds and sounds of inhaling saliva intrude into the blood flow sound detecting means. Therefore, even if the detection signal of the blood flow sound detecting means is analyzed, there is a problem that the presence or absence of the intracranial lesion site and the position thereof cannot be easily estimated.
そこで本発明は、異常血流音に基づく頭蓋内病変部位
の有無及び位置推定を高精度で行うことができる頭蓋内
血流音処理装置の提供を目的としている。Therefore, an object of the present invention is to provide an intracranial blood flow sound processing device capable of highly accurately determining the presence and position of an intracranial lesion site based on abnormal blood flow sounds.
［発明の構成］ （課題を解決するための手段） 本発明は、被検体の頭蓋内血流音を含む頭蓋内音を検
出する複数の血流音検出手段を有し、この血流音検出手
段の検出結果に基づいて頭蓋内血流音の解析を行う頭蓋
内血流音処理装置において、前記被検体からの心拍同期
信号を基に、複数の心拍時相の前記複数の検出結果よ
り、複数の検出結果相互の周波数相関を示す関数を求め
る第１手段と、求められた前記関数のピーク値の時間的
変化パターンに基づいて、血流音検出手段の検出結果中
の心拍とは非同期に一様なレベルで存在している雑音を
除去することで血流音成分の抽出を行う第２の手段を有
するものである。[Structure of the Invention] (Means for Solving the Problems) The present invention has a plurality of blood flow sound detecting means for detecting intracranial sound including intracranial blood flow sound of a subject, and detects the blood flow sound. In the intracranial blood flow sound processing device for analyzing the intracranial blood flow sound based on the detection result of the means, based on the heartbeat synchronization signal from the subject, from the plurality of detection results of a plurality of heartbeat time phase, The first means for obtaining a function indicating the frequency correlation between a plurality of detection results and the heartbeat in the detection result of the blood flow sound detection means are asynchronous with each other based on the temporal change pattern of the obtained peak value of the function. The second means is provided for extracting the blood flow sound component by removing the noise existing at a uniform level.
（作 用） 本発明では、被検体からの心拍同期信号を基に、複数
の心拍時相の前記複数の検出結果より、複数の検出結果
相互の周波数相関を示す関数を求め、求められた前記関
数のピーク値の時間的変化パターンに基づいて、血流音
検出手段の検出結果中の心拍とは非同期に一様なレベル
で存在している雑音を除去することで血流音成分の抽出
を行うようにしており、このようにすることで頭蓋内病
変部位の有無及び位置推定の高精度化を図っている。(Operation) In the present invention, based on the heartbeat synchronizing signal from the subject, a function indicating frequency correlation between the plurality of detection results is obtained from the plurality of detection results of the plurality of heartbeat time phases, and the obtained function is obtained. Based on the temporal change pattern of the peak value of the function, the blood flow sound component is extracted by removing the noise that exists at a uniform level asynchronously with the heartbeat in the detection result of the blood flow sound detection means. By doing so, the presence or absence of the intracranial lesion site and the position estimation are made highly accurate.
（実施例） 以下、本発明を図面に示す実施例に基づき詳細に説明
する。(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings.
第１図は本発明の一実施例である頭蓋内血流音処理装
置を被検体（通常は患者）Ｐに取り付けた状態を示して
いる。FIG. 1 shows a state in which an intracranial blood flow sound processing apparatus according to an embodiment of the present invention is attached to a subject (usually a patient) P.
同図に示すように、この頭蓋内血流音処理装置は、血
流音検出手段6a、6b、プリアンプ8a、8b、A/D変換器
９、電極10a、10b、10c、心電計11、バッファメモリ1
2、波形データ解析部13を有する。As shown in the figure, this intracranial blood flow sound processing device includes blood flow sound detection means 6a, 6b, preamplifiers 8a, 8b, A / D converter 9, electrodes 10a, 10b, 10c, electrocardiograph 11, Buffer memory 1
2. Has a waveform data analysis unit 13.
血流音検出手段6a、6bは、被検体Ｐの頭蓋内病変部よ
り生ずる血流音を含む頭蓋内音を検出するもので、例え
ば、第７図に示すものと同様に加速度検出器１を有して
成るものが適用される。この血流音検出手段は実際には
被検体Ｐの頭部に多数配置されるが、第１図ではそのう
ちの２個のみを示している。血流音検出手段6a、6bの検
出結果はプリアンプ8a、8bを介してA/D変換器９に取り
込まれるようになっている。また、電極10a、10b,10cは
被検体Ｐの心拍を検出するもので、この検出結果は心電
計11を介してA/D変換器９に取り込まれるようになって
いる。The blood flow sound detecting means 6a and 6b are for detecting intracranial sound including blood flow sound generated from the intracranial lesion of the subject P. For example, the acceleration detector 1 is similar to that shown in FIG. What has has to be applied. Although many blood flow sound detecting means are actually arranged on the head of the subject P, only two of them are shown in FIG. The detection results of the blood flow sound detecting means 6a, 6b are taken into the A / D converter 9 via the preamplifiers 8a, 8b. The electrodes 10a, 10b, 10c detect the heartbeat of the subject P, and the detection result is taken into the A / D converter 9 via the electrocardiograph 11.
A/D変換器９に取り込まれた検出結果は、デジタル信
号に変換された後にバッファメモリ12を介して波形デー
タ解析部13に取り込まれるようになっている。The detection result captured by the A / D converter 9 is converted into a digital signal and then captured by the waveform data analysis unit 13 via the buffer memory 12.
この波形データ解析部13は、波形データの解析を行う
もので、機能的に第１の手段13aと第２の手段13bとを有
する。第１の手段13aは、前記血流音検出手段6a、6bの
検出結果より、各チャンネル間の周波数相関を示す、例
えばコヒーレンス関数を求めるものであり、第２の手段
13bは、このコヒーレンス関数のピーク値の時間的変化
パターンに基づいて血流音検出手段の検出結果中の心拍
とは非同期に一様なレベルで存在している雑音を除去す
ることで血流音成分の抽出を行うものである。The waveform data analysis unit 13 analyzes the waveform data, and functionally has first means 13a and second means 13b. The first means 13a is for obtaining, for example, a coherence function indicating the frequency correlation between channels from the detection results of the blood flow sound detecting means 6a, 6b.
13b is based on the temporal change pattern of the peak value of the coherence function and removes the noise existing at a uniform level asynchronously with the heartbeat in the detection result of the blood flow sound detection means, thereby removing the blood flow sound. The components are extracted.
以下、第１図に示す頭蓋内血流音処理装置の動作を詳
細に説明する。The operation of the intracranial blood flow sound processing apparatus shown in FIG. 1 will be described in detail below.
第２図に示すように、頭蓋内の血流速度Ｖ、特に脳動
脈瘤などの血管病変の好発部位であるWillis輪近辺、た
とえば中大脳動脈の起始部ではその速度Ｖは一様でなく
変動しており、心電波形（ECG）Ｒ波が生じているＡ時
点では非常に遅く、これから所定時間経過後のＢ時点で
は非常に速い。一方、頭蓋内の異常血流音は、脳動脈瘤
ではそこに流れる血流のうず流音、動脈硬化などの血管
内の局所的狭窄部では乱流音が原因となって生じてい
る。これらうず流音、乱流音は頭蓋内の血流速度Ｖが遅
いＡ点付近では発生し難いが、血流速度が速いＢ時点付
近では発生し易く異常血流音のパワーが増大する。しか
し血流音以外の不必要な雑音は頭蓋内の血流速度Ｖの遅
いＡ時点及び速いＢ時点に関係なくあるレベルで一様に
発生し、それが血流音検出手段6a、6bに混入する。As shown in FIG. 2, the blood flow velocity V in the cranium, especially the velocity V is uniform in the vicinity of the circle of Willis, which is a common site of vascular lesions such as cerebral aneurysms, for example, at the origin of the middle cerebral artery. It is extremely slow at the time A when the electrocardiographic waveform (ECG) R wave is generated, and is very fast at the time B after a predetermined time has passed. On the other hand, the abnormal blood flow sound in the skull is caused by eddy flow sound of blood flow flowing in a cerebral aneurysm, and turbulent flow sound in a local constriction in a blood vessel such as arteriosclerosis. These eddy and turbulent sounds are unlikely to occur near the point A where the blood flow velocity V in the skull is slow, but are likely to occur near time B when the blood flow velocity is high, and the power of the abnormal blood flow sound increases. However, unnecessary noise other than the blood flow sound is uniformly generated at a certain level regardless of the slow A time point and the fast B time point of the blood flow velocity V in the skull, and it is mixed in the blood flow sound detecting means 6a, 6b. To do.
ここで、異常血流音が発生しない時相では有意な信号
はなく雑音成分がほとんどであるため、複数チャンネル
間の相関は弱くなり、任意の２チャンネル間のコヒーレ
ンス関数の値は小さい。一方、異常血流音が発生する時
相では上記とは逆に有意な信号が増加するためのコヒー
レンス関数の値は１に近くなる。従って、このようなコ
ヒーレンス関数の時間的変化のパターンを利用して異常
血流音を抽出することができる。Here, since there is no significant signal and most of the noise components are present in the time phase when no abnormal blood flow sound is generated, the correlation between a plurality of channels becomes weak and the value of the coherence function between any two channels is small. On the other hand, in the time phase in which abnormal blood flow sound is generated, the value of the coherence function for increasing a significant signal is close to 1 contrary to the above. Therefore, the abnormal blood flow sound can be extracted using such a pattern of the temporal change of the coherence function.
第３図に示す心電波形（ECG）は第１図に示す心電計1
1より得られたものである。第３図にある血流音検出手
段１からｎの波形は被検体Ｐの頭部に配置したｎ個の血
流音検出手段から検出された血流音を含む頭蓋内音であ
る。血流音検出手段１からｎの血流音を含む頭蓋内音は
A/D変換器９によりデジタルデータに変換され、頭蓋内
の血流速度Ｖが遅く異常血流音が非常に少ないＡ時点か
ら時間td1後の期間t1におけるデータ、血流速度Ｖが速
く異常血流音が多く含まれている時間td1から時間td2ま
での期間t2におけるデータというような期間ごとのデー
タとしてバッファメモリ12に記憶される。The electrocardiographic waveform (ECG) shown in FIG. 3 is the electrocardiograph 1 shown in FIG.
It is obtained from 1. Waveforms of blood flow sound detecting means 1 to n shown in FIG. 3 are intracranial sounds including blood flow sounds detected by n blood flow sound detecting means arranged on the head of the subject P. The intracranial sounds including the blood flow sounds of blood flow sound detection means 1 to n are
The data is converted into digital data by the A / D converter 9 and the blood flow velocity V in the skull is slow and the abnormal blood flow sound is very small. It is stored in the buffer memory 12 as data for each period such as the data in the period t2 from the time td1 to the time td2 in which a lot of flowing sound is included.
第４図に心電図のQRSトリガ（Ｒ波）時点からの任意
の２つのチャンネル（ここでは、チャンネル１と２）で
検出された血流音を含む頭蓋内音波形を示す。QRSトリ
ガ（Ｒ波）時点からの時相としての送れ時間が０、td
1、td2、td3、・・・から期間間隔t1、t2、t3、・・・
の２チャンネルのデータのコヒーレンス関数は例えば第
５図のようになり、そのピーク値ａ、ｂ、ｃ、ｄは各時
相によって増減する。FIG. 4 shows an intracranial sound waveform including blood flow sound detected in any two channels (here, channels 1 and 2) from the time point of QRS trigger (R wave) of the electrocardiogram. Sending time as a time phase from the time of QRS trigger (R wave) is 0, td
From 1, td2, td3, ... Period intervals t1, t2, t3, ...
For example, the coherence function of the data of the two channels is as shown in FIG. 5, and the peak values a, b, c, d increase and decrease depending on each time phase.
頭蓋内病変部位のない正常人の場合、呼吸音等の雑音
が混入していなければ、血流速度の速い期間t3の血流音
にも異常血流音はなく、第６図において１点波線で示す
ようにコヒーレンス関数（Coh）の各時相での値は小さ
く、かつ各時相間での値の変動は小さい。しかし、異常
血流音がある場合には、血流速度の速い部分での有意な
信号のため同図において実線で示すように期間t3及びそ
の近辺でコヒーレンス関数は１に近い値となる。また、
呼吸音などの心拍とは非同期の雑音は各チャンネルに一
様なレベルで混入するため、頭蓋内の血流速度パターン
に無関係に第６図において波線でしめすようなパターン
となる。In the case of a normal person with no intracranial lesion, if no noise such as breathing noise is mixed, there is no abnormal blood flow sound even in the blood flow sound during the period t3 where the blood flow velocity is fast, and the dashed line in FIG. As shown in, the value of the coherence function (Coh) is small in each time phase, and the variation of the value between each time phase is small. However, when there is an abnormal blood flow sound, the coherence function becomes a value close to 1 in the period t3 and its vicinity as shown by the solid line in the figure because it is a significant signal in the portion where the blood flow velocity is high. Also,
Since noises such as breath sounds that are not synchronized with the heartbeat are mixed into each channel at a uniform level, the pattern shown by the wavy line in FIG. 6 is obtained regardless of the blood flow velocity pattern in the skull.
波形データ解析部13において、先ず第１の手段13aに
より、心電波形の同期パルスから順次時相をずらしなが
ら各チャンネル間（例えば任意の２チャンネル間）のコ
ヒーレンス関数が求められ、次に第２の手段13bにより
コヒーレンス関数のピーク値の時間的変化パターンに基
づいて、血流音検出手段の検出結果中の心拍とは非同期
に一様なレベルで存在している雑音が除去され、血流音
成分の抽出が行われる。そして、この血流音成分に基づ
いて乱流、うず流音の特徴抽出が行われる。In the waveform data analysis unit 13, first, the first means 13a obtains the coherence function between each channel (for example, between two arbitrary channels) while sequentially shifting the time phase from the synchronous pulse of the electrocardiographic waveform, and then the second Based on the temporal change pattern of the peak value of the coherence function, the means 13b removes the noise existing at a uniform level asynchronously with the heartbeat in the detection result of the blood flow sound detection means and removes the blood flow sound. Extraction of components is performed. Then, the feature extraction of the turbulent flow and the eddy flow sound is performed based on the blood flow sound component.
尚、本発明は上記実施例に限定されるものではなく、
種々の変形実施が可能であるのは言うまでもない。The present invention is not limited to the above embodiment,
It goes without saying that various modifications can be made.
［発明の効果］ 以上詳述したように本発明によれば、被検体からの心
拍同期信号を求に、複数の心拍時相の前記複数の検出結
果より、複数の検出結果相互の周波数相関を示す関数を
求め、その求められた前記関数のピーク値の時間的変化
パターンに基づいて、血流音検出手段の検出結果中の心
拍とは非同期に一様なレベルで存在している雑音を除去
するようにしたので、血流音成分を的確に抽出すること
ができ、頭蓋内病変部位の有無及び位置推定を高精度で
行うことができるという優れた効果を奏する。[Effects of the Invention] As described in detail above, according to the present invention, the frequency correlation between a plurality of detection results is obtained from the plurality of detection results of a plurality of heartbeat time phases in obtaining the heartbeat synchronization signal from the subject. The indicated function is obtained, and the noise existing at a uniform level asynchronous with the heartbeat in the detection result of the blood flow sound detection means is removed based on the temporal change pattern of the obtained peak value of the function. Therefore, the blood flow sound component can be accurately extracted, and the excellent effect that the presence / absence of the intracranial lesion site and the position can be estimated with high accuracy is achieved.
第１図は本発明の一実施例装置のブロック図、第２図は
血流速度の特性図、第３図は心電波形と血流速度の関係
を示した図。第４図乃至第６図は本実施例装置の作用説
明のための波形図、第７図は血流音検出手段の構成説明
図である。 6a、6b……血流音検出手段、７……被検体、13……波形
データ処理部、13a……第１の手段、13b……第２の手
段。FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention, FIG. 2 is a characteristic diagram of blood flow velocity, and FIG. 3 is a diagram showing a relationship between an electrocardiographic waveform and blood flow velocity. 4 to 6 are waveform diagrams for explaining the operation of the apparatus of this embodiment, and FIG. 7 is a configuration explanatory diagram of blood flow sound detecting means. 6a, 6b ... Blood flow sound detecting means, 7 ... Subject, 13 ... Waveform data processing section, 13a ... First means, 13b ... Second means.
Claims (1)
出する複数の血流音検出手段を有し、この血流音検出手
段の検出結果に基づいて頭蓋内血流音の解析を行う頭蓋
内血流音処理装置において、前記被検体からの心拍同期
信号を基に、複数の心拍時相の前記複数の検出結果よ
り、複数の検出結果相互の周波数相関を示す関数を求め
る第１手段と、求められた前記関数のピーク値の時間的
変化パターンに基づいて、血流音検出手段の検出結果中
の心拍とは非同期に一様なレベルで存在している雑音を
除去することで血流音成分の抽出を行う第２の手段を有
することを特徴とする頭蓋内血流音処理装置。1. A plurality of blood flow sound detecting means for detecting an intracranial sound including an intracranial blood flow sound of a subject, the intracranial blood flow sound being detected based on the detection result of the blood flow sound detecting means. In the intracranial blood flow sound processing device that performs analysis, based on the heartbeat synchronization signal from the subject, from the plurality of detection results of a plurality of heartbeat time phases, obtain a function indicating a frequency correlation between the plurality of detection results. Based on the first means and the obtained temporal change pattern of the peak value of the function, noise existing at a uniform level is removed asynchronously with the heartbeat in the detection result of the blood flow sound detecting means. Therefore, the intracranial blood flow sound processing device is provided with a second means for extracting a blood flow sound component.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63026475A JP2672546B2 (en) | 1988-02-09 | 1988-02-09 | Intracranial blood flow sound processor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63026475A JP2672546B2 (en) | 1988-02-09 | 1988-02-09 | Intracranial blood flow sound processor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01204644A JPH01204644A (en) | 1989-08-17 |
| JP2672546B2 true JP2672546B2 (en) | 1997-11-05 |
Family
ID=12194533
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63026475A Expired - Fee Related JP2672546B2 (en) | 1988-02-09 | 1988-02-09 | Intracranial blood flow sound processor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2672546B2 (en) |
-
1988
- 1988-02-09 JP JP63026475A patent/JP2672546B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01204644A (en) | 1989-08-17 |
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