Optical coherence elastography method and device, electronic equipment and storage medium

Abstract

The invention relates to the technical field of imaging, in particular to an optical coherence elastography method and device, electronic equipment and a storage medium, and the method comprises the steps: outputting laser meeting a preset time periodicity condition and a preset linear change condition through a sweep frequency light source; generating a driving signal containing an analog signal or a digital signal according to the trigger signal; scanning the sample according to the driving signal; applying mechanical excitation to the sample by using the driving signal, and respectively generating a two-dimensional image and a three-dimensional image of the sample according to the two-dimensional elastic wave and the three-dimensional elastic wave; reflecting the sample arm laser and then interfering with the reference arm laser; and reconstructing the interference signal into a sample structure image, generating biomechanical information of the sample according to the elastic wave, and determining a final optical coherence elastography result according to the biomechanical information, the three-dimensional imaging and the two-dimensional imaging. Therefore, the problem that an existing optical coherence elastography method cannot realize two-dimensional dynamic imaging and cannot realize three-dimensional living body imaging is solved.

Description

Technical Field

[0001] The present invention relates to the field of imaging technology, and in particular to an optical coherence elastic imaging method, device, electronic equipment and storage medium. Background Art

[0002] Elastography: The mechanical properties of human tissue can reflect a person's health. Many diseases, such as liver fibrosis, arteriosclerosis, and cancer, can cause changes in the mechanical properties of human tissue. By measuring the mechanical properties of human tissue, some diseases can be diagnosed. In ancient times, people used palpation to diagnose certain diseases. With the advancement of technology, people hope to characterize the mechanical properties of tissues in vivo non-invasively and non-destructively. Over the past 30 years, a series of methods have been developed for characterizing the mechanical properties of soft tissues in vivo, collectively referred to as elastography (because the measurement results are often expressed as images of soft and hard distributions). Typical elastography methods include shear wave ultrasound elastography and magnetic resonance elastography. These elastography methods are highly adaptable and have a wide range of applications, but the equipment costs are high, making them unsuitable for specific application scenarios.

[0003] Optical coherence elastography. Research has shown that many diseases (such as liver fibrosis, tumors, and vascular plaques) alter the mechanical properties of corresponding tissues. Therefore, in vivo measurement of the mechanical properties of soft tissues is crucial for the diagnosis of many diseases, especially early diagnosis. Elastography, a technology developed based on this background, has found initial application in liver fibrosis diagnosis and breast nodule classification. Optical coherence elastography (OCE) is an elastography technique developed based on optical coherence tomography (OCT). The basic principle of OCE is to use a mechanical stimulus to induce static or dynamic deformation in soft tissues. This deformation is measured using OCT, and the biomechanical properties of the soft tissue are then inferred from the measured deformation. OCE based on static deformation has found initial application in intraoperative tumor tissue boundary determination. However, static OCE is limited in that it can only qualitatively measure the elastic modulus of soft tissue. OCE based on dynamic deformation (shear waves) can quantitatively determine the biomechanical properties of soft tissue and has a wide range of applications.

[0004] Corneal OCE measurement has important clinical applications. The cornea is a transparent, soft tissue approximately 0.5 mm thick. It provides approximately two-thirds of the refractive power of the ocular system. Therefore, a stable corneal shape is crucial for maintaining normal vision. Under the influence of intraocular pressure, the cornea assumes a crescent shape. When degenerative changes occur in the center of the cornea, its shape may become conical, severely impairing vision. Continuous progression of keratoconus may ultimately require a corneal transplant. Laser surgery has also become an important method for correcting myopia. Laser ablation of the cornea reduces its refractive power, achieving the goal of correcting myopia. During preoperative planning for laser surgery, accurate knowledge of the corneal biomechanical properties can help precisely calculate corneal deformation after ablation and better assess the safety and accuracy of laser surgery for myopia.

[0005] In the related technology, a non-invasive acoustic testing method and device for the elasticity of soft tissue, the device generates tangential vibration deformation on the surface of the tissue being tested, picks up the surface vibration through a piezoelectric transducer, and analyzes the vibration signal to measure the anisotropy of the tissue; a method for estimating the elasticity of soft elastic solids from surface wave measurements, the device consists of an exciter and multiple vibration sensors (piezoelectric sensors), so as to measure the surface wave velocity / dispersion properties and obtain the mechanical properties of the material; a method and device for estimating the elasticity of soft solids by measuring surface waves, the device consists of an external vibration source and a vibration sensor array. Summary of the Invention

[0006] The present invention provides an optical coherence elastography method, apparatus, electronic device, and storage medium to address the primary limitation of existing optical coherence elastography methods: slow imaging speed. Specifically, optical coherence elastography uses a MB scanning mode, and generally requires only seconds for two-dimensional imaging. Therefore, this method cannot be used for dynamically changing biological tissues. Furthermore, three-dimensional imaging requires only minutes, a speed that is unsuitable for measurements on living tissues.

[0007] A first aspect of the present invention provides an optical coherence elastic imaging method, comprising the following steps: using a swept-frequency light source to output a laser that satisfies a preset time periodicity condition and a preset linear change condition; using a waveform generator card to receive a trigger signal of the swept-frequency light source, and generating a drive signal comprising an analog signal or a digital signal according to the trigger signal; scanning a sample according to the drive signal to generate a scanning result; based on the scanning result, applying mechanical excitation to the sample using the drive signal to generate two-dimensional elastic waves and three-dimensional elastic waves in the sample, and generating a two-dimensional image and a three-dimensional image of the sample respectively according to the two-dimensional elastic waves and the three-dimensional elastic waves; using a coherent optical path to separate the laser into a reference arm laser and a sample arm laser, and after reflecting the sample arm laser, interfering with the reference arm laser to generate an interference signal; reconstructing the interference signal into a sample structural image, and extracting the elastic wave in the sample based on the sample structural image to generate biomechanical information of the sample according to the elastic wave, and determining the final optical coherence elastic imaging result according to the biomechanical information, the three-dimensional imaging, and the two-dimensional imaging.

[0008] Optionally, in one embodiment of the present invention, after the sample arm laser is reflected and interfered with the reference arm laser to generate an interference signal, it also includes: measuring the interference signal and converting the interference signal into an analog signal of the sample; or storing the interference signal to generate a digital signal of the sample.

[0009] Optionally, in one embodiment of the present invention, the driving signal is used to apply mechanical excitation to the sample to generate two-dimensional elastic waves and three-dimensional elastic waves in the sample, and two-dimensional imaging and three-dimensional imaging of the sample are generated according to the two-dimensional elastic waves and the three-dimensional elastic waves, respectively, including: determining the imaging sequence of the sample with the frequency of the swept light source as a clock, and receiving the sinusoidal signal of the waveform generating card based on the imaging sequence; using the sinusoidal signal to apply excitation to the sample to implement a target scanning mode along the direction of the second direction axis while maintaining a stationary direction of the first direction axis; looping the target scanning mode three times until the three-dimensional scanning of the sample meets a preset end condition, generating a three-dimensional elastic wave of the sample, and determining the three-dimensional imaging of the sample according to the three-dimensional elastic wave.

[0010] Optionally, in one embodiment of the present invention, the interference signals corresponding to the target scanning modes are:

[0011]

[0012]

[0013] in, is the interference signal corresponding to the first scan, is the interference signal corresponding to the second scan, is the interference signal corresponding to the third scan, is the static interference signal of the pixel point, and 、 and Respectively represent the amplitude and phase of the fluctuation on the left and right sides of the pixel; The static interference signal of the pixel point is obtained by averaging the interference signals of three scans:

[0014] in, is the static interference signal of the pixel point, is the interference signal corresponding to the first scan, is the interference signal corresponding to the second scan, is the interference signal corresponding to the third scan; The amplitude and phase of the fluctuations on the left and right sides of the pixel are:

[0015]

[0016] in, and The fluctuation signal is obtained by removing the static signal from the first two scanning signals. is the amplitude of the fluctuation on the right side of the pixel, is the amplitude of the fluctuation on the left side of the pixel; The fluctuation signal obtained by removing the static signal from the first two scanning signals is:

[0017]

[0018] in, is the interference signal corresponding to the first scan, is the interference signal corresponding to the second scan, is the static interference signal of the pixel point, and 、 and Respectively represent the amplitude and phase of the fluctuation on the left and right sides of the pixel.

[0019] Optionally, in one embodiment of the present invention, the driving signal is used to apply mechanical excitation to the sample to generate two-dimensional elastic waves and three-dimensional elastic waves in the sample, and two-dimensional imaging and three-dimensional imaging of the sample are generated according to the two-dimensional elastic waves and the three-dimensional elastic waves, respectively. It also includes: based on the frequency of the swept laser and the piezoelectric effect of the preset excitation system, driving the contact probe to transmit vibration to the sample to generate two-dimensional elastic waves of the sample, and determining the two-dimensional imaging of the sample according to the two-dimensional elastic waves.

[0020] The second embodiment of the present invention provides an optical coherence elastic imaging device, comprising: an output module for outputting a laser that satisfies a preset time periodicity condition and a preset linear change condition using a swept-frequency light source; a receiving module for receiving a trigger signal of the swept-frequency light source using a waveform generating card, and generating a driving signal including an analog signal or a digital signal according to the trigger signal; a scanning module for scanning a sample according to the driving signal to generate a scanning result; and a generating module for applying mechanical excitation to the sample using the driving signal based on the scanning result to generate two-dimensional elastic waves and three-dimensional elastic waves in the sample. A two-dimensional image and a three-dimensional image of the sample are generated according to the two-dimensional elastic wave and the three-dimensional elastic wave respectively; an interference module is used to use a coherent optical path to divide the laser into a reference arm laser and a sample arm laser, and reflect the sample arm laser to interfere with the reference arm laser to generate an interference signal; an imaging module is used to reconstruct the interference signal into a sample structure image, and extract the elastic wave in the sample based on the sample structure image to generate biomechanical information of the sample according to the elastic wave, and determine the final optical coherence elastic imaging result according to the biomechanical information, the three-dimensional imaging and the two-dimensional imaging.

[0021] Optionally, in one embodiment of the present invention, it also includes: a measurement module for measuring the interference signal after the sample arm laser is reflected and interfered with the reference arm laser to generate an interference signal, and converting the interference signal into an analog signal of the sample; or a storage module for storing the interference signal to generate a digital signal of the sample.

[0022] Optionally, in one embodiment of the present invention, the generation module includes: a determination unit, used to determine the imaging sequence of the sample using the frequency of the swept light source as a clock, and receive the sinusoidal signal of the waveform generating card based on the imaging sequence; an implementation unit, used to use the sinusoidal signal to excite the sample to implement a target scanning mode along the direction of the second direction axis while remaining stationary in the direction of the first direction axis; a generation unit, used to cyclically execute the target scanning mode three times until the three-dimensional scanning of the sample meets a preset end condition, generates a three-dimensional elastic wave of the sample, and determines the three-dimensional imaging of the sample based on the three-dimensional elastic wave.

[0023] Optionally, in one embodiment of the present invention, the interference signals corresponding to the target scanning modes are:

[0024]

[0025]

[0026] in, is the interference signal corresponding to the first scan, is the interference signal corresponding to the second scan, is the interference signal corresponding to the third scan, is the static interference signal of the pixel point, and 、 and Respectively represent the amplitude and phase of the fluctuation on the left and right sides of the pixel; The static interference signal of the pixel point is obtained by averaging the interference signals of three scans:

[0027] in, is the static interference signal of the pixel point, is the interference signal corresponding to the first scan, is the interference signal corresponding to the second scan, is the interference signal corresponding to the third scan; The amplitude and phase of the fluctuations on the left and right sides of the pixel are:

[0028]

[0029] in, and The fluctuation signal is obtained by removing the static signal from the first two scanning signals. is the amplitude of the fluctuation on the right side of the pixel, is the amplitude of the fluctuation on the left side of the pixel; The fluctuation signal obtained by removing the static signal from the first two scanning signals is:

[0030]

[0031] in, is the interference signal corresponding to the first scan, is the interference signal corresponding to the second scan, is the static interference signal of the pixel point, and 、 and Respectively represent the amplitude and phase of the fluctuation on the left and right sides of the pixel.

[0032] Optionally, in one embodiment of the present invention, the generation module further includes: a transmission unit, which is used to drive the contact probe to transmit vibration to the sample based on the frequency of the swept laser and the piezoelectric effect of the preset excitation system to generate a two-dimensional elastic wave of the sample, and determine the two-dimensional imaging of the sample based on the two-dimensional elastic wave.

[0033] A third aspect of the present invention provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the optical coherence elasticity imaging method as described in the above embodiment.

[0034] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program, which implements the above optical coherence elasticity imaging method when executed by a processor.

[0035] A fifth aspect of the present invention provides a computer program product, which stores a computer program. When the computer program is executed by a processor, the computer program implements the above optical coherence elasticity imaging method.

[0036] The embodiments of the present invention can increase existing imaging speeds by hundreds of times, achieving millisecond-level 2D imaging speeds, enabling 2D dynamic imaging, and 3D imaging speeds of less than one second, enabling in vivo and 3D optical coherence elastic imaging. This overcomes the limitations of existing optical coherence elastic imaging: the inability to achieve 2D dynamic imaging and 3D in vivo imaging.

[0037] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 This is a flow chart of an optical coherence elastography method provided according to an embodiment of the present invention; Figure 2 A diagram showing the hardware system configuration according to an embodiment of the present invention; Figure 3 is a schematic diagram of a system imaging sequence according to one embodiment of the present invention; Figure 4 is a schematic diagram of three-dimensional imaging according to an embodiment of the present invention; Figure 5 A schematic diagram of a PZT-based excitation system design according to an embodiment of the present invention; Figure 6 is a schematic diagram of two-dimensional imaging according to an embodiment of the present invention; Figure 7 is a schematic diagram of dynamic imaging according to an embodiment of the present invention; Figure 8 is a schematic diagram of a coherent optical path according to an embodiment of the present invention; Figure 9 A schematic structural diagram of an optical coherence elastography device according to an embodiment of the present invention; Figure 10 A schematic structural diagram of an electronic device provided according to an embodiment of the present invention.

[0039] Among them, 10 is an optical coherence elastic imaging device; 100 is an output module, 200 is a receiving module, 300 is a scanning module, 400 is a generation module, 500 is an interference module, 600 is an imaging module; 901 is a memory, 902 is a processor, and 903 is a communication interface. DETAILED DESCRIPTION

[0040] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0041] The following describes, with reference to the accompanying drawings, an optical coherence elastography method, apparatus, electronic device, and storage medium according to embodiments of the present invention. The primary limitation of existing optical coherence elastography methods, as mentioned in the background art, is their slow imaging speed. Specifically, optical coherence elastography employs a MB scanning mode, and generally, 2D imaging takes seconds. Therefore, this method cannot be used for dynamically changing biological tissues. Furthermore, 3D imaging takes minutes, making this imaging speed prohibitive for in vivo measurements. The present invention provides an optical coherence elastography method that increases imaging speed by approximately 300 times, reducing 2D imaging time from seconds to milliseconds, enabling dynamic 2D imaging, and 3D imaging time to less than 1 second, enabling 3D in vivo imaging. Through innovative imaging sequence design and imaging algorithms, efficient coordination between the laser, scanning mirror, and excitation module is achieved. This overcomes the primary limitation of existing optical coherence elastography methods, namely, their slow imaging speed. Specifically, optical coherence elastography employs a MB scanning mode, and generally, 2D imaging takes seconds. Therefore, this method cannot be used for dynamically changing biological tissues. At the same time, three-dimensional imaging takes about minutes, and this imaging speed cannot be used for measurements on living bodies.

[0042] Specifically, Figure 1 A schematic flow chart of an optical coherence elastography method provided by an embodiment of the present invention.

[0043] like Figure 1 As shown, the optical coherence elastography method includes the following steps: In step S101 , a frequency-sweeping light source is used to output laser light that meets a preset time periodicity condition and a preset linear variation condition.

[0044] In the actual implementation process, Figure 2 As shown, embodiments of the present invention utilize a swept-frequency light source to stably output laser light whose wavelength varies periodically and linearly over time. The laser sweep frequency is fa. During the periodic laser sweep, a trigger signal is sent to the waveform generator card, synchronizing the waveform generator card with the swept-frequency light source.

[0045] It should be noted that the preset time periodicity condition and the preset linear change condition can be set by those skilled in the art according to actual conditions and are not specifically limited here.

[0046] In step S102 , a waveform generating card is used to receive a trigger signal of a frequency-sweep light source, and a driving signal including an analog signal or a digital signal is generated according to the trigger signal.

[0047] The embodiment of the present invention can utilize a waveform generating card to receive a trigger signal of a frequency-sweeping light source, and use the trigger signal of the frequency-sweeping light source as a clock to synchronously generate analog / digital signals to drive the scanning galvanometer and the excitation module.

[0048] In step S103 , the sample is scanned according to the driving signal to generate a scanning result.

[0049] In actual implementation, the embodiment of the present invention utilizes a scanning galvanometer to receive a driving signal from a waveform generating card, and a motor drives two plane mirrors to perform scanning along the X and Y axes, thereby generating scanning results and achieving three-dimensional imaging.

[0050] In step S104, based on the scanning result, a driving signal is used to apply mechanical excitation to the sample to generate two-dimensional elastic waves and three-dimensional elastic waves in the sample, and two-dimensional imaging and three-dimensional imaging of the sample are generated according to the two-dimensional elastic waves and the three-dimensional elastic waves, respectively.

[0051] As a possible implementation method, an embodiment of the present invention can apply mechanical excitation to the sample using a drive signal based on the scanning results to generate two-dimensional elastic waves and three-dimensional elastic waves in the sample, and generate two-dimensional imaging and three-dimensional imaging of the sample based on the two-dimensional elastic waves and three-dimensional elastic waves, respectively. The excitation module used in the present invention includes a power amplifier module and an actuator module. The drive signal of the waveform generating card is received, and the drive signal is amplified by the power amplifier module therein to drive the execution module to generate a mechanical signal. The mechanical signal acts on the sample and excites elastic waves therein. There are various designs of the execution module. In one embodiment, a piezoelectric driver is used as the execution module; in another embodiment, an ultrasonic transducer is used as the execution module.

[0052] Optionally, in one embodiment of the present invention, a driving signal is used to apply mechanical excitation to the sample to generate two-dimensional elastic waves and three-dimensional elastic waves in the sample, and two-dimensional imaging and three-dimensional imaging of the sample are generated respectively based on the two-dimensional elastic waves and three-dimensional elastic waves, including: determining the imaging sequence of the sample using the frequency of the swept light source as a clock, and receiving a sinusoidal signal from a waveform generating card based on the imaging sequence; applying excitation to the sample using the sinusoidal signal to implement a target scanning mode along the direction of the second direction axis while maintaining a stationary direction of the first direction axis; looping the target scanning mode three times until the three-dimensional scanning of the sample meets a preset end condition, generating a three-dimensional elastic wave of the sample, and determining the three-dimensional imaging of the sample based on the three-dimensional elastic wave.

[0053] It can be understood that, in the embodiment of the present invention, the first direction axis may be the Y-axis, and the second direction axis may be the X-axis.

[0054] Among them, the imaging sequence proposed in the embodiment of the present invention is as follows Figure 3As shown, the Y axis is Y-axis, the X axis is X-axis, and the entire imaging sequence is based on the frequency of the swept light source (fa)—— Figure 3 The Aline shown in the figure is the clock. The excitation module receives the sinusoidal signal from the waveform generator card and applies excitation to the sample. At the same time, the galvanometer mirror corresponding to the Y-axis direction remains stationary, and the X-axis direction starts the B-scan mode. This scan is divided into three times, namely B11, B12 and B13. Figure 3 As shown, at the beginning of the three B scans, the phases of the corresponding excitation module sinusoidal signals are 0, 2π / 3 and 4π / 3 respectively. The three B modes contain the same number of Alines, but the number of Alines contained is Nx. Nx can be arbitrary. After completing the above three B scans, the Y axis is adjusted by an angle, and the above B scan mode is repeated in the X axis direction to obtain B21, B22 and B23. Similarly, the above process is repeated. When the Y axis scans for the i-th time, the X axis performs three B scans to obtain three B mode scans Bi1, Bi2 and Bi3. A total of Ny scans are performed in the Y axis direction as needed. Similarly, Ny can be arbitrary. The above three-dimensional scan contains a total of 3*Nx*Ny Alines, and the total duration is 3*Nx*Ny / fa.

[0055] For example, in a three-dimensional embodiment, a PZT (piezoelectric crystal sensor) excitation system is used with an excitation frequency of 3 kHz, Nx = 200, and Ny = 100. Therefore, the total time for one measurement is: 200 × 100 × 3 × (1 / 100e3) = 0.6 seconds. Figure 4 The three cloud diagrams show the elastic waves in the xy, yz, and xz sections, respectively.

[0056] Conventional optical coherence elastography uses the MB scanning mode. For the same 3D scan, the total number of Alines required is approximately 900*Nx*Ny. Therefore, the imaging sequence proposed in the present invention is 300 times faster than conventional methods.

[0057] An embodiment of the present invention proposes a new imaging sequence that uses three consecutive B-mode scans to obtain full-field elastic waves. Compared with the traditional MB mode, this imaging sequence reduces the time required for imaging from seconds to millimeter levels, increasing the imaging speed by approximately 300 times, reducing the two-dimensional imaging time from seconds to milliseconds, and realizing dynamic two-dimensional imaging; it reduces the three-dimensional imaging time to less than 1 second, enabling three-dimensional in vivo imaging.

[0058] Optionally, in one embodiment of the present invention, the interference signals corresponding to the target scanning modes are:

[0059]

[0060]

[0061] in, is the interference signal corresponding to the first scan, is the interference signal corresponding to the second scan, is the interference signal corresponding to the third scan, is the static interference signal of the pixel point, and 、 and Represent the amplitude and phase of the fluctuation on the left and right sides of the pixel respectively; The static interference signal of the pixel point is obtained by averaging the interference signals of three scans:

[0062] in, is the static interference signal of the pixel point, is the interference signal corresponding to the first scan, is the interference signal corresponding to the second scan, is the interference signal corresponding to the third scan; The amplitude and phase of the fluctuations on the left and right sides of the pixel are:

[0063]

[0064] in, and The fluctuation signal is obtained by removing the static signal from the first two scanning signals. is the amplitude of the fluctuation on the right side of the pixel, is the amplitude of the fluctuation on the left side of the pixel; The fluctuation signal obtained by removing the static signal from the first two scanning signals is:

[0065]

[0066] in, is the interference signal corresponding to the first scan, is the interference signal corresponding to the second scan, is the static interference signal of the pixel point, and 、 and Represents the amplitude and phase of the fluctuation on the left and right sides of the pixel respectively.

[0067] Specifically, the present invention proposes a new imaging algorithm. This method uses three B-mode scans synchronized with the excitation, namely Bi1, Bi2, and Bi3, to calculate the amplitude and phase of the elastic wave. The specific method is as follows: 1) For any pixel, the interference signal between the sample light and the reference light is ,in, is the static interference signal of the pixel point.

[0068] 2) The phases of the excitations corresponding to the three B modes differ by 2 π / 3, the corresponding interference signal is:

[0069]

[0070]

[0071] 3) Static interference signal of pixel points , which can be obtained by averaging the interference signals of three scans:

[0072] 4) Calculation: and .

[0073] 5) The amplitude and phase of the fluctuation on the left and right sides of the pixel can be obtained by and The solution is:

[0074]

[0075] Optionally, in one embodiment of the present invention, a driving signal is used to apply mechanical excitation to the sample to generate two-dimensional elastic waves and three-dimensional elastic waves in the sample, and two-dimensional imaging and three-dimensional imaging of the sample are generated respectively based on the two-dimensional elastic waves and three-dimensional elastic waves. It also includes: based on the frequency of the swept laser and the piezoelectric effect of the preset excitation system, driving the contact probe to transmit vibration to the sample to generate two-dimensional elastic waves of the sample, and determining the two-dimensional imaging of the sample based on the two-dimensional elastic waves.

[0076] It can be understood that the preset excitation system can be a PZT excitation system.

[0077] Taking 2D imaging as an example, the method of the present invention takes approximately 6 milliseconds, while conventional methods require approximately 2000 milliseconds, a 300-fold increase in imaging speed. Therefore, the method of the present invention can achieve dynamic 2D imaging. Using the method of the present invention, 3D imaging can be achieved in less than 1 second, enabling in vivo 3D imaging.

[0078] In an example of two-dimensional imaging, a hydrogel sample is used as the imaging object, and the Figure 5 The excitation system shown in Figure 1 is based on a swept laser with a frequency of fa = 100 kHz. The excitation system is based on the piezoelectric effect of a PZT, which drives the contact probe, transmitting vibrations to the sample. This excitation system is suitable for exciting elastic waves in the 100 Hz to 100 kHz range. In this specific example, the excitation frequency is 3 kHz.

[0079] Figure 6 A represents the two-dimensional elastic wave measured by the method of the present invention, where Nx = 200. Thus, the time required for one imaging session is approximately 200 × 3 × (1 / 100e3) = 6 milliseconds. In comparison, using the existing MB mode, each M-scan uses 1000 Alines, Nx = 200, and the total time is approximately 200 × 1000 × (1 / 100e3) = 2000 milliseconds. The wave image obtained using the MB mode is shown in the figure below. Figure 6 As shown in B.

[0080] Furthermore, in a dynamic imaging embodiment, the present invention can measure the tension wave velocity in a plastic film. By dynamically changing the tension in the film, the velocity in the film is dynamically changed. In this embodiment, the velocity in the film can be continuously measured. Figure 7 As shown in the figure, the tension in the film is changed within 5 seconds, and the tension in the film is continuously measured using a 2D ultrafast imaging method. This demonstrates that the method described in this invention can achieve dynamic and continuous imaging. In contrast, the traditional MB scanning mode takes 2 seconds per measurement and is unable to measure this dynamic change.

[0081] In step S105 , the laser light is divided into reference arm laser light and sample arm laser light by using a coherent optical path, and the sample arm laser light is reflected and interfered with the reference arm laser light to generate an interference signal.

[0082] In the actual implementation process, the embodiment of the present invention can use the Michelson coherent optical path to divide the received laser into two paths: the reference arm and the sample arm. The laser in the sample arm is reflected by the sample and interferes with the laser in the reference arm. Figure 8 shown.

[0083] Optionally, in one embodiment of the present invention, after the sample arm laser is reflected and interfered with the reference arm laser to generate an interference signal, it also includes: measuring the interference signal and converting the interference signal into an analog signal of the sample; or storing the interference signal to generate a digital signal of the sample.

[0084] Specifically, the high-speed data acquisition system in this embodiment of the present invention consists of a photodetector module and a high-speed data acquisition card module. The photodetector measures the interference signal and converts it into an analog signal. The high-speed data acquisition card stores the interference signal as a digital signal through A / D conversion.

[0085] In step S106, the interference signal is reconstructed into a sample structure image, and elastic waves in the sample are extracted based on the sample structure image to generate biomechanical information of the sample according to the elastic waves, and the final optical coherence elastic imaging result is determined based on the biomechanical information, three-dimensional imaging and two-dimensional imaging.

[0086] In actual implementation, embodiments of the present invention utilize a post-processing and display system: A post-processing algorithm reconstructs the collected interference signal into a sample structural image. Simultaneously, elastic wave information is extracted and post-processed to obtain biomechanical information (e.g., elasticity, viscoelasticity, anisotropy, etc.). The final optical coherence elastography results are determined based on this biomechanical information, along with 3D and 2D imaging. The structural image and biomechanical information are then displayed or printed in the form of reports, charts, or graphs.

[0087] The embodiments of the present invention greatly improve the speed of existing optical coherence elastic imaging, increasing the speed of optical coherence elastic imaging by about 300 times, and can realize dynamic two-dimensional imaging, three-dimensional imaging, etc.

[0088] According to the optical coherence elastic imaging method proposed in the embodiment of the present invention, the imaging speed can be increased by about 300 times, the two-dimensional imaging time can be reduced from seconds to milliseconds, and dynamic two-dimensional imaging can be achieved; the three-dimensional imaging time can be reduced to less than 1 second, and three-dimensional in vivo imaging can be achieved. Through innovative imaging sequence design and imaging algorithms, efficient coordinated operation of the laser, scanning galvanometer and excitation module is achieved. In this way, the main limitation of the existing optical coherence elastic imaging method, which is the slow imaging speed, is solved. Specifically, optical coherence elastic imaging adopts MB scanning mode. Generally speaking, the time required for two-dimensional imaging is on the order of seconds. Therefore, this method cannot be used for dynamically changing biological tissues. At the same time, the time required for three-dimensional imaging is on the order of minutes, and this imaging speed cannot be used for measurements on living bodies.

[0089] Next, an optical coherence elastography apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0090] Figure 9Schematic diagram of the structure of an optical coherence elastography device according to an embodiment of the present invention.

[0091] like Figure 9 As shown, the optical coherence elastic imaging device 10 includes: an output module 100 , a receiving module 200 , a scanning module 300 , a generating module 400 , an interference module 500 and an imaging module 600 .

[0092] Specifically, the output module 100 is configured to utilize a swept frequency light source to output laser light that meets a preset time periodicity condition and a preset linear variation condition.

[0093] The receiving module 200 is used to receive a trigger signal of the frequency sweeping light source by using a waveform generating card, and generate a driving signal including an analog signal or a digital signal according to the trigger signal.

[0094] The scanning module 300 is used to scan the sample according to the driving signal and generate a scanning result.

[0095] The generation module 400 is used to apply mechanical excitation to the sample using a driving signal based on the scanning results to generate two-dimensional elastic waves and three-dimensional elastic waves in the sample, and generate two-dimensional imaging and three-dimensional imaging of the sample according to the two-dimensional elastic waves and three-dimensional elastic waves respectively.

[0096] The interference module 500 is used to separate the laser into reference arm laser and sample arm laser by using a coherent optical path, and to reflect the sample arm laser and interfere with the reference arm laser to generate an interference signal.

[0097] The imaging module 600 is used to reconstruct the interference signal into a sample structure image, and extract the elastic waves in the sample based on the sample structure image to generate biomechanical information of the sample based on the elastic waves, and determine the final optical coherence elastic imaging result based on the biomechanical information, three-dimensional imaging and two-dimensional imaging.

[0098] Optionally, in one embodiment of the present invention, the optical coherence elastography apparatus 10 further includes: a measurement module or a storage module.

[0099] The measurement module is used to reflect the sample arm laser and interfere with the reference arm laser to generate an interference signal, measure the interference signal, and convert the interference signal into an analog signal of the sample.

[0100] Or, a storage module, used to store the interference signal to generate a digital signal of the sample.

[0101] Optionally, in one embodiment of the present invention, the generation module 400 includes: a determination unit, an implementation unit, and a generation unit.

[0102] The determining unit is used to determine the imaging sequence of the sample using the frequency of the swept frequency light source as a clock, and receive the sinusoidal signal from the waveform generating card based on the imaging sequence.

[0103] The implementation unit is used to apply excitation to the sample using a sinusoidal signal, so as to implement a target scanning mode along the direction of the second direction axis while keeping the direction of the first direction axis unchanged.

[0104] The generating unit is used to execute the target scanning mode three times in a loop until the three-dimensional scanning of the sample meets the preset end condition, generate the three-dimensional elastic wave of the sample, and determine the three-dimensional imaging of the sample according to the three-dimensional elastic wave.

[0105] Optionally, in one embodiment of the present invention, the interference signals corresponding to the target scanning modes are:

[0106]

[0107]

[0108] in, is the interference signal corresponding to the first scan, is the interference signal corresponding to the second scan, is the interference signal corresponding to the third scan, is the static interference signal of the pixel point, and 、 and Represent the amplitude and phase of the fluctuation on the left and right sides of the pixel respectively; The static interference signal of the pixel point is obtained by averaging the interference signals of three scans:

[0109] in, is the static interference signal of the pixel point, is the interference signal corresponding to the first scan, is the interference signal corresponding to the second scan, is the interference signal corresponding to the third scan; The amplitude and phase of the fluctuations on the left and right sides of the pixel are:

[0110]

[0111] in, and The fluctuation signal is obtained by removing the static signal from the first two scanning signals. is the amplitude of the fluctuation on the right side of the pixel, is the amplitude of the fluctuation on the left side of the pixel; The fluctuation signal obtained by removing the static signal from the first two scanning signals is:

[0112]

[0113] in, is the interference signal corresponding to the first scan, is the interference signal corresponding to the second scan, is the static interference signal of the pixel point, and 、 and Represents the amplitude and phase of the fluctuation on the left and right sides of the pixel respectively.

[0114] Optionally, in one embodiment of the present invention, the generating module 400 further includes: a transmitting unit.

[0115] Among them, the transmission unit is used to drive the contact probe to transmit vibration to the sample based on the frequency of the swept laser and the piezoelectric effect of the preset excitation system, so as to generate a two-dimensional elastic wave of the sample, and determine the two-dimensional imaging of the sample according to the two-dimensional elastic wave.

[0116] It should be noted that the above explanations of the optical coherence elastography method embodiment are also applicable to the optical coherence elastography device of this embodiment, and will not be repeated here.

[0117] According to the optical coherence elastic imaging device proposed in the embodiment of the present invention, the imaging speed is increased by about 300 times, and the two-dimensional imaging time is reduced from seconds to milliseconds, which can realize dynamic two-dimensional imaging; the three-dimensional imaging time is reduced to less than 1 second, which can realize three-dimensional living body imaging. Through innovative imaging sequence design and imaging algorithms, efficient coordinated operation of the laser, scanning galvanometer and excitation module is achieved. In this way, the main limitation of the existing optical coherence elastic imaging method is solved, which is the slow imaging speed. Specifically, optical coherence elastic imaging adopts MB scanning mode. Generally speaking, the time required for two-dimensional imaging is on the order of seconds. Therefore, this method cannot be used for dynamically changing biological tissues. At the same time, the time required for three-dimensional imaging is on the order of minutes, and this imaging speed cannot be used for measurement on living bodies.

[0118] Figure 10 This is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. The electronic device may include: A memory 1001 , a processor 1002 , and a computer program stored in the memory 1001 and executable on the processor 1002 .

[0119] When the processor 1002 executes the program, the optical coherence elastography method provided in the above embodiment is implemented.

[0120] Furthermore, the electronic device further includes: The communication interface 1003 is used for communication between the memory 1001 and the processor 1002 .

[0121] The memory 1001 is used to store computer programs that can be run on the processor 1002 .

[0122] The memory 1001 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0123] If the memory 1001, processor 1002, and communication interface 1003 are implemented independently, the communication interface 1003, memory 1001, and processor 1002 can be connected to each other via a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be divided into address buses, data buses, control buses, etc. For ease of representation, Figure 10 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0124] Optionally, in a specific implementation, if the memory 1001, the processor 1002 and the communication interface 1003 are integrated on a chip, the memory 1001, the processor 1002 and the communication interface 1003 can communicate with each other through an internal interface.

[0125] The processor 1002 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present invention.

[0126] This embodiment further provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the above optical coherence elasticity imaging method is implemented.

[0127] An embodiment of the present invention further provides a computer program product, which stores a computer program. When the program is executed by a processor, the above optical coherence elastography method is implemented.

[0128] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0129] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "N" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0130] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or N executable instructions for implementing a custom logical function or step of a process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention pertain.

[0131] The logic and / or steps represented in a flowchart or otherwise described herein, for example, can be considered a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" is any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (not exhaustive) of computer-readable media include: an electrical connection with one or more wires (electronic devices), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program can be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing it in other suitable ways as necessary, and then storing it in a computer memory.

[0132] It should be understood that various components of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiment, the N steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having logic gate circuits for implementing logical functions on data signals, an application-specific integrated circuit having suitable combinational logic gate circuits, a programmable gate array (PGA), a field-programmable gate array (FPGA), etc.

[0133] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0134] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing module, or each unit may exist physically separately, or two or more units may be integrated into a single module. The aforementioned integrated modules may be implemented in the form of hardware or in the form of software functional modules. If the integrated modules are implemented in the form of software functional modules and sold or used as independent products, they may also be stored in a computer-readable storage medium.

[0135] The storage medium mentioned above may be a read-only memory, a magnetic disk, or an optical disk, etc. Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and are not to be construed as limiting the present invention. Persons skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. An optical coherence elastic imaging method, characterized in that: The following steps are involved: Utilizing a swept frequency light source to output a laser that satisfies a preset time periodicity condition and a preset linear variation condition; Utilizing a waveform generating card to receive a trigger signal of the frequency-sweep light source, and generating a driving signal including an analog signal or a digital signal according to the trigger signal; Scanning the sample according to the driving signal to generate a scanning result; Based on the scanning result, applying mechanical excitation to the sample using the drive signal to generate two-dimensional elastic waves and three-dimensional elastic waves in the sample, and generating a two-dimensional image and a three-dimensional image of the sample according to the two-dimensional elastic waves and the three-dimensional elastic waves, respectively; The laser light is divided into a reference arm laser light and a sample arm laser light by using a coherent optical path, and the sample arm laser light is reflected and interfered with the reference arm laser light to generate an interference signal; The interference signal is reconstructed into a sample structure image, and elastic waves in the sample are extracted based on the sample structure image to generate biomechanical information of the sample according to the elastic waves, and a final optical coherence elastic imaging result is determined based on the biomechanical information, the three-dimensional imaging and the two-dimensional imaging.

2. The optical coherence elastography method according to claim 1, wherein: After the sample arm laser is reflected and interfered with the reference arm laser to generate an interference signal, the method further includes: Measuring the interference signal and converting the interference signal into an analog signal of the sample; Alternatively, the interference signal is stored to generate a digital signal of the sample.

3. The optical coherence elastography method according to claim 1, wherein: The step of applying mechanical excitation to the sample using the driving signal to generate two-dimensional elastic waves and three-dimensional elastic waves in the sample, and generating two-dimensional imaging and three-dimensional imaging of the sample based on the two-dimensional elastic waves and the three-dimensional elastic waves, respectively, comprises: determining an imaging sequence of the sample using the frequency of the swept-frequency light source as a clock, and receiving a sinusoidal signal from the waveform generating card based on the imaging sequence; Exciting the sample using the sinusoidal signal to implement a target scanning pattern along a second direction axis while maintaining the sample stationary along the first direction axis; The target scanning mode is executed cyclically three times until the three-dimensional scanning of the sample meets a preset end condition, a three-dimensional elastic wave of the sample is generated, and a three-dimensional imaging of the sample is determined based on the three-dimensional elastic wave.

4. The optical coherence elastography method according to claim 3, wherein: The interference signals corresponding to the target scanning modes are: in, is the interference signal corresponding to the first scan, is the interference signal corresponding to the second scan, is the interference signal corresponding to the third scan, is the static interference signal of the pixel point, and 、 and Respectively represent the amplitude and phase of the fluctuation on the left and right sides of the pixel; The static interference signal of the pixel point is obtained by averaging the interference signals of three scans: in, is the static interference signal of the pixel point, is the interference signal corresponding to the first scan, is the interference signal corresponding to the second scan, is the interference signal corresponding to the third scan; The amplitude and phase of the fluctuations on the left and right sides of the pixel are: in, and The fluctuation signal is obtained by removing the static signal from the first two scanning signals. is the amplitude of the fluctuation on the right side of the pixel, is the amplitude of the fluctuation on the left side of the pixel; The fluctuation signal obtained by removing the static signal from the first two scanning signals is: in, is the interference signal corresponding to the first scan, is the interference signal corresponding to the second scan, is the static interference signal of the pixel point, and 、 and Respectively represent the amplitude and phase of the fluctuation on the left and right sides of the pixel.

5. The optical coherence elastography method according to claim 1, wherein: The method further comprises applying mechanical excitation to the sample using the driving signal to generate two-dimensional elastic waves and three-dimensional elastic waves in the sample, and generating two-dimensional imaging and three-dimensional imaging of the sample based on the two-dimensional elastic waves and the three-dimensional elastic waves, respectively. Based on the frequency of the swept laser and the piezoelectric effect of the preset excitation system, the contact probe is driven to transmit vibration to the sample to generate a two-dimensional elastic wave of the sample, and a two-dimensional imaging of the sample is determined based on the two-dimensional elastic wave.

6. An optical coherence elastic imaging device, characterized in that: include: An output module, configured to utilize a frequency-sweeping light source to output laser light that satisfies a preset time periodicity condition and a preset linear variation condition; A receiving module, configured to receive a trigger signal of the frequency-sweeping light source using a waveform generating card, and generate a driving signal including an analog signal or a digital signal according to the trigger signal; A scanning module, configured to scan the sample according to the driving signal and generate a scanning result; a generating module, configured to apply mechanical excitation to the sample using the driving signal based on the scanning result to generate two-dimensional elastic waves and three-dimensional elastic waves in the sample, and generate a two-dimensional image and a three-dimensional image of the sample according to the two-dimensional elastic waves and the three-dimensional elastic waves, respectively; an interference module, configured to separate the laser light into a reference arm laser light and a sample arm laser light by using a coherent optical path, and to reflect the sample arm laser light and interfere with the reference arm laser light to generate an interference signal; An imaging module is used to reconstruct the interference signal into a sample structure image, and extract elastic waves in the sample based on the sample structure image, so as to generate biomechanical information of the sample according to the elastic waves, and determine the final optical coherence elastic imaging result based on the biomechanical information, the three-dimensional imaging and the two-dimensional imaging.

7. The optical coherence elastography apparatus according to claim 6, wherein: Also includes: a measurement module, configured to, after reflecting the sample arm laser and interfering with the reference arm laser to generate an interference signal, measure the interference signal and convert the interference signal into an analog signal of the sample; Or, a storage module, used to store the interference signal to generate a digital signal of the sample.

8. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the optical coherence elastography method according to any one of claims 1 to 5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the optical coherence elastography method according to any one of claims 1 to 5.

10. A computer program product comprising a computer program, characterized in that The computer program is executed to implement the optical coherence elastography method according to any one of claims 1 to 5.

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