CN112782279A - Non-contact thermoacoustic imaging method and device - Google Patents
Non-contact thermoacoustic imaging method and device Download PDFInfo
- Publication number
- CN112782279A CN112782279A CN201911084029.1A CN201911084029A CN112782279A CN 112782279 A CN112782279 A CN 112782279A CN 201911084029 A CN201911084029 A CN 201911084029A CN 112782279 A CN112782279 A CN 112782279A
- Authority
- CN
- China
- Prior art keywords
- contact
- sample
- microwave
- thermoacoustic
- ultrasonic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/04—Analysing solids
- G01N29/06—Visualisation of the interior, e.g. acoustic microscopy
- G01N29/0654—Imaging
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/0093—Detecting, measuring or recording by applying one single type of energy and measuring its conversion into another type of energy
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves
- A61B5/0507—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves using microwaves or terahertz waves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N22/00—Investigating or analysing materials by the use of microwaves or radio waves, i.e. electromagnetic waves with a wavelength of one millimetre or more
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/22—Details, e.g. general constructional or apparatus details
- G01N29/24—Probes
- G01N29/2431—Probes using other means for acoustic excitation, e.g. heat, microwaves, electron beams
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Physics & Mathematics (AREA)
- Pathology (AREA)
- General Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Biophysics (AREA)
- Molecular Biology (AREA)
- Veterinary Medicine (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Medical Informatics (AREA)
- Acoustics & Sound (AREA)
- Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- Public Health (AREA)
- Electromagnetism (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Radiology & Medical Imaging (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
The invention provides a non-contact thermoacoustic imaging method and a device, and the method comprises the following steps: the microwave source with the pulse width of 500ns and the frequency of 6G is used as an excitation source, short pulse microwaves are output by a waveguide and then radiated onto a sample, the sample is irradiated by electromagnetic waves to absorb energy to generate a tiny temperature rise instantly, so that a thermal expansion effect is caused, a thermoacoustic signal belonging to an ultrasonic wave range is excited, the excited ultrasonic signal carries information of the electromagnetic wave absorption characteristics of the irradiated sample and is transmitted outwards through the sample, the ultrasonic signal around tissues is collected, and an image reconstruction is performed by using a filtering back-projection algorithm to reconstruct a microwave absorption distribution diagram in the sample. The traditional method for receiving thermoacoustic signals utilizes the piezoelectric principle of an ultrasonic transducer, thermoacoustic signals belonging to the ultrasonic wave range are transmitted out of a sample, are coupled by oil and then are received by the ultrasonic transducer, and the invention provides an optical method for detecting ultrasonic signals, which is an air-coupled and non-contact thermoacoustic imaging method and device.
Description
Technical Field
The invention belongs to the technical field of microwave thermoacoustic imaging, and particularly relates to a non-contact thermoacoustic imaging method and device.
Background
The thermoacoustic imaging technology is a tomography technology for exciting thermoacoustic signals by irradiating biological tissues with pulse microwaves, has high contrast, high resolution and deep imaging depth, and is a novel nondestructive testing technology with good application prospect.
In the traditional thermoacoustic imaging technology, a coupling medium, usually mineral oil, is required between a sample and a detector, so that a measured object needs to be completely immersed in the mineral oil, the experimental conditions are limited, the device has a complex and large structure, secondary damage can be caused to biological tissues, and the development of the thermoacoustic imaging technology towards clinical application is greatly hindered.
Disclosure of Invention
The invention aims at overcoming the defects of the prior method and provides a novel method for detecting ultrasonic waves, which uses a Fabry-Perot etalon as an ultrasonic probe and uses an optical method to detect the ultrasonic waves; the detection part of the ultrasonic probe consists of two reflectors; the effective detection window size of the ultrasonic probe is 5mm x 3.5 mm; the ultrasonic probe belongs to a membraneless ultrasonic detector; the ultrasonic probe and the tested sample do not need a coupling medium, namely, the probe achieves the effect of non-contact detection of ultrasonic waves.
It is another aspect of the present invention to provide for a non-contact thermoacoustic imaging device.
(1) The pulse sequence generator triggers the microwave source to emit short pulse microwaves, and the repetition frequency is 10 Hz;
(2) irradiating the sample with microwave to expand the sample to produce thermoacoustic signal;
(3) the thermoacoustic signals are detected by a non-contact ultrasonic probe, amplified by a signal amplifier, collected by a high-speed digital acquisition card and stored in a computer. After one-time acquisition is finished, the Labview program controls the X-Y two-dimensional scanning platform to move one point for the next data acquisition.
(4) And reconstructing a microwave absorption distribution map of the sample at the position, namely a thermo-acoustic image by using a data processing program.
The invention provides a non-contact imaging method with high imaging contrast and imaging depth. A microwave source with the pulse width of 500ns and the frequency of 6G is used as an excitation source, short pulse microwaves are output by a waveguide and then radiated onto a sample, the sample is irradiated by electromagnetic waves to absorb energy and instantly generate a tiny temperature rise to cause a thermal expansion effect to excite a thermoacoustic signal belonging to an ultrasonic wave range, the excited ultrasonic signal carries information of the electromagnetic wave absorption characteristic of the irradiated sample and is transmitted outwards through the sample, a Fabry-Perot etalon consisting of two immovable reflectors is used as an ultrasonic detector to detect the ultrasonic waves, the ultrasonic signals around tissues are collected, the ultrasonic signals are collected and stored by a high-speed digital collecting card, after one signal is collected, an X-Y two-dimensional scanning platform drives the ultrasonic detector to move to the next point for collection until the signal collection of all areas is completed, and data processing is carried out by a filter back projection algorithm, the microwave absorption distribution diagram in the sample can be reconstructed, and the non-contact thermoacoustic imaging is completed.
The device also comprises an instrument fixing/supporting instrument assembly which is used for fixing the stepping motor X-Y two-dimensional scanning platform and the ultrasonic probe.
The rated voltage of the signal amplifier is 15V, the gain of 50dB, and the frequency application range is 30kH to 600 MHz.
The microwave generator emits microwaves with the main frequency of 6GHz, the pulse width of 500ns and the repetition frequency of 10 HZ.
The sampling rate of the high-speed digital acquisition card is 50MS/s
The computer comprises an acquisition control program, a stepping motor control program and a real-time acquisition system based on Labview software control, excited areas can correspond to data of the excited areas one by one, and a data processing program is run by Matlab software.
The sampling rate of the high-speed digital acquisition card is 50 MS/s.
The process of collecting and controlling program level signal processing installed on the computer is compiled by Labview and Matlab programs.
The X-Y sweepThe tracing platform consists of two vertically crossed platforms with a minimum step distance of 5
m motor composition.
Drawings
FIG. 1 is a diagram of a non-contact thermoacoustic imaging apparatus.
FIG. 2 is a block diagram of a non-contact ultrasonic probe
FIG. 3 is a diagram of the thermoacoustic signal of a sample.
FIG. 4 is a non-contact thermoacoustic imaging view.
Detailed Description
FIG. 1 is a diagram of a main apparatus for non-contact thermoacoustic imaging according to the embodiment, including a function generator 2-1, a microwave source 2-2, a microwave transmitting antenna 2-3, a sample 2-4, a non-contact ultrasonic detector 2-5, an amplifier 2-6, a data acquisition card 2-7, a computer and display 2-8, an X-Y scanning platform 2-9, and a DC power supply 2-10. The computer is respectively connected with the display, the function generator, the data acquisition card and the X-Y scanning platform; the non-contact ultrasonic detector, the direct-current power supply, the amplifier and the data acquisition card are sequentially connected; the microwave source is connected with the function generator, the function generator can trigger the microwave source to reflect pulse signals, the transmitted pulse signals are transmitted to the lower portion of a sample through the transmitting antenna, and the non-contact ultrasonic detector is placed above the sample.
Fig. 2 illustrates a structure of a non-contact ultrasonic detector, in which a fabry-perot etalon formed by two reflecting mirrors is a detecting member, and a detection light enters the fabry-perot etalon, and a light beam interferes between the mirror surfaces, and an ultrasonic wave irradiated on a sample surface changes the density of a medium between the mirror surfaces, thereby causing a change in refractive index, so that an optical path difference of the detection light is changed, resulting in a change in a proportion of reflected light, which is detected by a photodiode. The effective detection window size of the ultrasonic detector is 5mm by 3.5 mm.
The microwave source of this embodiment is a microwave generator (BW6000HPT) of micro electro mechanical technology ltd, north of shanxi, and has a transmission frequency of 6GHz, a pulse width of 500ns, a peak power of transmitted pulses of 250KW, and a repetition frequency of 10 Hz.
The function generator sets the frequency range to be 1-1000Hz, the amplitude to be 1-50vpp and the pulse width to be 0.001-100 mus. The transmitting antenna is used for radiating high-power microwaves, is in a shape of a circular horn, has a gain range of 1-100dB, and is used for radiating the high-power microwaves, wherein the caliber of the transmitting antenna in the embodiment is preferably 110mm, and the gain is preferably 3 dB.
The direct current power supply respectively provides direct current voltage for the amplifier and the X-Y scanning platform, the rated voltage of the amplifier is 15V, the gain is 50dB, and the frequency use range is 30kH to 600 MHz; the X-Y scanning platform consists of two motors which are vertically crossed and have the minimum step distance of 5 mu m, and the voltage range of the motors is 15V to 36V.
The data acquisition card and the computer can be used for data acquisition and imaging. The data acquisition card is used for acquiring thermoacoustic time domain signals, and the sampling rate of the data acquisition card in the embodiment is 50MS/s, and meets the acquisition requirement. The CPU model of the computer is a 4GHz Intel Core 2 i7-4790K dual-Core processor, and the requirement on the computing speed is met; and (4) utilizing MATLAB to realize a back projection algorithm to reconstruct the image to obtain a microwave thermoacoustic image.
The working principle of the device is as follows: the function generator emits a pulse sequence to trigger the microwave generator to emit pulse microwaves, the pulse microwaves are uniformly irradiated onto tissues to be detected through the emitting antenna, the tissues to be detected absorb the microwave energy to cause instant temperature rise, the pulse width of the microwaves is narrow, the absorbed energy cannot be thermally diffused within the microwave pulse duration, adiabatic expansion occurs, and a thermoacoustic effect is generated, namely, the thermal energy is converted into mechanical energy to be radiated in an ultrasonic mode. The ultrasonic wave changes the density of a medium between mirror surfaces of a Fabry-Perot etalon in the non-contact ultrasonic detector to cause the change of the refractive index, thereby changing the optical path difference to cause the proportion change of the reflected light, and the change is measured by a photodiode, thereby measuring the thermoacoustic signal. The intensity of the reflected light received by the fabry-perot etalon is expressed as: i _ R = [1-1/(1+ F } sin, where 2 [ (δ/2) ]. I _0, where I _0 is the intensity of incident light, F = 4R/[ 1-R ] (2), R is the reflectivity of the mirror surface, n is the refractive index of the medium in the Fabry-Perot etalon, λ is the wavelength of incident light in vacuum, and d is the distance between the mirrors.
Experiments show that the non-contact ultrasonic detector can image within 7cm from the sample, the closer the non-contact ultrasonic detector is to the sample, the better the image quality is, and the optimal distance between the non-contact ultrasonic detector and the sample is 2.5cm in the example.
The imaging method is based on the non-contact thermoacoustic imaging device and comprises the following steps:
samples were prepared from 3% agar and placed in the waveguide port.
Setting relevant parameters of the instrument, and connecting and opening a microwave generator, a high-speed data acquisition card, a computer, a function generator, a direct current power supply, an amplifier and other equipment.
Triggering a microwave generator to generate pulse microwaves by using a pulse sequence transmitted by a function generator; the pulse microwave is transmitted to the sample pool through the transmitting antenna, the tissue to be detected absorbs the microwave energy to cause instant temperature rise to generate a thermoacoustic signal, and the signal is received by the non-contact ultrasonic detector.
The high-speed digital acquisition card stores the signal into a computer, and the X-Y scanning platform drives the non-contact ultrasonic detector to move to the next position for acquisition; and processing the data on a computer by using MATLAB software, and reconstructing an image by using a filtering back projection algorithm.
The above description is only for the preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can substitute or change the technical solution and the inventive concept of the present invention within the scope of the present invention.
Claims (10)
1. A non-contact thermoacoustic imaging device, characterized by: the system comprises a function generator, a microwave source, a microwave transmitting antenna, a non-contact ultrasonic detector, a signal amplifier, a high-speed data acquisition card 2, a computer, a display, an X-Y scanning platform and a direct-current power supply, wherein the computer is respectively connected with the display, the function generator, the data acquisition card and the X-Y scanning platform; the non-contact ultrasonic detector, the direct-current power supply, the amplifier and the data acquisition card are sequentially connected; the microwave source is connected with a function generator, the function generator can trigger the microwave source to reflect pulse signals, the transmitted pulse signals are transmitted to the lower portion of a sample through a transmitting antenna, a non-contact ultrasonic detector is placed above the sample, a computer is provided with an acquisition control program, a stepping motor control program and a data processing program, a detection portion of the non-contact ultrasonic detector is a Fabry-Perot etalon formed by two immovable reflecting mirrors, incident light emitted from the interior of the detector enters the Fabry-Perot etalon and interferes, when ultrasonic waves exist, the ultrasonic waves change the density of media in the Fabry-Perot etalon, so that optical path difference is changed, the proportion of reflected light is changed, and the proportion of the reflected light measured by a photodiode in the detector is changed.
2. The non-contact thermoacoustic imaging device according to claim 1, wherein: the intensity of the reflected light received by the fabry-perot etalon is expressed as:
wherein I0Is the intensity of the incident light and,
r is the reflectivity of the mirror surface,
n is the refractive index of the medium in the Fabry-Perot etalon, lambda is the wavelength of incident light in vacuum, and d is the distance between the reflectors.
3. The non-contact heat-content imaging device of claim 2, wherein: the non-contact ultrasonic probe is within 7cm from the sample, and the effective detection window size of the non-contact ultrasonic probe is 5mm x 3.5 mm.
4. A non-contact thermal imaging apparatus according to claim 3, wherein: the non-contact ultrasound probe is at a distance of 2.5 cm.
5. A non-contact thermoacoustic imaging method and apparatus according to claim 1, characterized in that: the microwave source is a high-power microwave generator with the pulse width of 500ns and the frequency of 6 GHz.
6. A non-contact thermoacoustic imaging method and apparatus according to claim 1, characterized in that: the rated voltage of the signal amplifier is 15V, the gain of 50dB and the bandwidth of the signal amplifier is 30 kH-600 MHz.
7. A non-contact thermoacoustic imaging method and apparatus according to claim 1, characterized in that: the X-Y scanning platform consists of two motors which are vertically intersected and have the minimum step distance of 5 mu m.
8. A non-contact thermoacoustic imaging method and apparatus according to claim 1, characterized in that: the sampling rate of the high-speed digital acquisition card is 50 MS/s.
9. A non-contact thermoacoustic imaging method and apparatus according to claim 1, characterized in that: the computer is provided with an acquisition control program, a stepping motor control program and a real-time acquisition system based on LABVIEW software control, and can correspond the excited areas to the data one by one, and a data processing program is run by Matlab software.
10. A method of using the non-contact thermoacoustic imaging device of any of claims 1-9, wherein: the method comprises the following steps:
(1) preparing a sample by using 3% agar, and placing the sample at a waveguide port of a microwave transmitting antenna;
(2) triggering a microwave generator to generate pulse microwaves by using a pulse sequence transmitted by a function generator; the transmitting frequency of the microwave is 6GHz, the pulse width is 500ns, the peak power of the transmitted pulse is 250KW, the repetition frequency is 10Hz, the pulse microwave is transmitted into the sample pool through the microwave transmitting antenna, the tissue to be detected absorbs the microwave energy to cause instant expansion and temperature rise to generate thermoacoustic signals, the signals are received by the non-contact ultrasonic detector, and the distance between the non-contact ultrasonic detector and the sample is within 7 cm;
(3) the thermoacoustic signals are detected by a non-contact ultrasonic probe, amplified by a signal amplifier, collected by a high-speed digital acquisition card and stored in a computer, and after one-time collection is completed, the X-Y two-dimensional scanning platform moves by one point to carry out the next data acquisition;
(4) and (3) reconstructing a microwave absorption distribution map, namely a thermo-acoustic image, of the sample by using a data processing program and a filtering back projection algorithm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911084029.1A CN112782279B (en) | 2019-11-07 | 2019-11-07 | Non-contact thermoacoustic imaging method and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911084029.1A CN112782279B (en) | 2019-11-07 | 2019-11-07 | Non-contact thermoacoustic imaging method and device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112782279A true CN112782279A (en) | 2021-05-11 |
| CN112782279B CN112782279B (en) | 2023-04-07 |
Family
ID=75748052
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911084029.1A Active CN112782279B (en) | 2019-11-07 | 2019-11-07 | Non-contact thermoacoustic imaging method and device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112782279B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113640319A (en) * | 2021-08-06 | 2021-11-12 | 电子科技大学 | Snowflake beef imaging device based on microwave thermoacoustic technology |
| CN113820398A (en) * | 2021-09-30 | 2021-12-21 | 电子科技大学 | Polarized microwave thermoacoustic imaging device and method |
| CN114343720A (en) * | 2021-12-07 | 2022-04-15 | 华南师范大学 | Endoscopic microwave thermoacoustic imaging method and device |
| CN114343720B (en) * | 2021-12-07 | 2024-05-28 | 华南师范大学 | Endoscopic microwave thermo-acoustic imaging method and device |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101825497A (en) * | 2010-03-30 | 2010-09-08 | 华南师范大学 | System and method for measuring temperature in real time based on thermoacoustic effect |
| CN106073779A (en) * | 2016-07-08 | 2016-11-09 | 华南师范大学 | A kind of microwave thermoacoustic color ultrasound bimodal breast imaging detection apparatus and method |
| CN107788982A (en) * | 2017-11-09 | 2018-03-13 | 华南师范大学 | A kind of microwave thermoacoustic early liver cancer detection means and method |
| CN107788980A (en) * | 2017-10-25 | 2018-03-13 | 华南师范大学 | Microwave thermoacoustic colorful ultrasonic bimodal nutrient infusion amount detecting device and method |
| CN110179498A (en) * | 2019-07-02 | 2019-08-30 | 四川大学华西医院 | A kind of thermal acoustic imaging system and its control method for lymphedema imaging |
-
2019
- 2019-11-07 CN CN201911084029.1A patent/CN112782279B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101825497A (en) * | 2010-03-30 | 2010-09-08 | 华南师范大学 | System and method for measuring temperature in real time based on thermoacoustic effect |
| CN106073779A (en) * | 2016-07-08 | 2016-11-09 | 华南师范大学 | A kind of microwave thermoacoustic color ultrasound bimodal breast imaging detection apparatus and method |
| CN107788980A (en) * | 2017-10-25 | 2018-03-13 | 华南师范大学 | Microwave thermoacoustic colorful ultrasonic bimodal nutrient infusion amount detecting device and method |
| CN107788982A (en) * | 2017-11-09 | 2018-03-13 | 华南师范大学 | A kind of microwave thermoacoustic early liver cancer detection means and method |
| CN110179498A (en) * | 2019-07-02 | 2019-08-30 | 四川大学华西医院 | A kind of thermal acoustic imaging system and its control method for lymphedema imaging |
Non-Patent Citations (1)
| Title |
|---|
| TAKAO TANAKA ET AL.: "Nondestructive Detection of Small Internal Defects in Carbon Steel by Laser Ultrasonics", 《JAPANESE JOURNAL OF APPLIED PHYSICS》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113640319A (en) * | 2021-08-06 | 2021-11-12 | 电子科技大学 | Snowflake beef imaging device based on microwave thermoacoustic technology |
| CN113820398A (en) * | 2021-09-30 | 2021-12-21 | 电子科技大学 | Polarized microwave thermoacoustic imaging device and method |
| CN114343720A (en) * | 2021-12-07 | 2022-04-15 | 华南师范大学 | Endoscopic microwave thermoacoustic imaging method and device |
| CN114343720B (en) * | 2021-12-07 | 2024-05-28 | 华南师范大学 | Endoscopic microwave thermo-acoustic imaging method and device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112782279B (en) | 2023-04-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU713650B2 (en) | Method and system for 3-D acoustic microscopy using short pulse excitation and 3-D acoustic microscope for use therein | |
| CN101918811B (en) | Confocal photoacoustic microscopy with optical lateral resolution | |
| US6041248A (en) | Method and apparatus for frequency encoded ultrasound-modulated optical tomography of dense turbid media | |
| CN107713990A (en) | A kind of thermoacoustic, optoacoustic, ultrasonic three mode tumor of breast detection means and method | |
| EP2553425B1 (en) | Photoacoustic imaging apparatus and photoacoustic imaging method | |
| CN112782279B (en) | Non-contact thermoacoustic imaging method and device | |
| Lashkari et al. | Linear frequency modulation photoacoustic radar: optimal bandwidth and signal-to-noise ratio for frequency-domain imaging of turbid media | |
| JP2002514756A (en) | Thermoacoustic tissue scanner | |
| CN107860742B (en) | Reflective terahertz time-domain near-field scanning microscope | |
| CN105092705A (en) | Multi-mode signal detection method and multi-mode signal detection system for rail defects | |
| CN106725348A (en) | A kind of absorber absorption coefficient measurement and the simultaneously lossless detection method and its device of photoacoustic imaging | |
| CN105572049A (en) | Opto-acoustic quantitative elasticity imaging method and device | |
| CN108888238A (en) | A kind of photoacoustic microscope and imaging method based on ultrasonic reflection plate with holes | |
| CN113406008B (en) | Photoacoustic imaging device and method based on white light interference | |
| CN110261315A (en) | A kind of scanning near-field opto-acoustic microscopic imaging instrument | |
| US20150008326A1 (en) | Electromagnetic wave pulse measuring device and method, and application device using the same | |
| CN1230125C (en) | Focusing supersonic modulation reflection type optical chromatography imaging method and its apparatus | |
| CN108051369B (en) | Non-contact all-optical photoacoustic imaging device and method thereof | |
| Telenkov et al. | Frequency domain photoacoustic correlation (radar) imaging: a novel methodology for non-invasive imaging of biological tissues | |
| Rui et al. | Gigahertz optoacoustic imaging for cellular imaging | |
| CN113848184A (en) | Microcavity photoacoustic imaging system based on flexible substrate | |
| CN207306654U (en) | A kind of absorber absorption coefficient measurement and the at the same time non-destructive testing device of photoacoustic imaging | |
| CN111481198B (en) | Laser-induced ultrasonic excitation method and device under magnetoacoustic monitoring | |
| CN110057776A (en) | A kind of integrated form Terahertz confocal imaging device and imaging method based on waveguiding structure | |
| CN114967090B (en) | Photoacoustic pathology microscopic imaging system and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |