Human peripheral blood vessel photoacoustic three-dimensional imaging device and imaging method thereof

Abstract

The application discloses a kind of human peripheral blood vessel photoacoustic three-dimensional imaging device and imaging method thereof, belong to blood vessel imaging field.The application provides detailed blood vessel structure and blood flow dynamic information by high resolution and functional monitoring ability of photoacoustic imaging, promote early identification and treatment effect evaluation to common pathological changes such as diabetic foot and peripheral arterial disease;Meanwhile, the application adopts mechanical system, and the detection front end of higher quality can be carried and stably operated, to obtain better photoacoustic imaging result;The application has highly stable precision scanning imaging mode, and various imaging modes are convenient for clinical application;Through the arrangement of imaging tank and its lifting structure, it is ensured that the switching of imaging mode can be applied in limited space, so as to be suitable for gantry type three-dimensional mobile device layout.The application is expected to promote the portability of equipment, reduce equipment development cost, be widely applied in clinical practice and community medical treatment, and improve disease management level.

Description

Technical Field

[0001] This invention relates to vascular imaging technology, specifically to a photoacoustic three-dimensional imaging device for human peripheral blood vessels and its imaging method. Background Technology

[0002] Peripheral small vessels (limbs, trunk, and face, etc.) are closely related to the morphology and function of numerous diseases, such as diabetic foot and peripheral artery disease. Traditional imaging techniques such as ultrasound, CT, and MRI have limitations in imaging peripheral small vessels, including insufficient resolution, high equipment cost, radiation risks, and the toxicity or allergies of contrast agents. Photoacoustic imaging, as an emerging technology, combines the high contrast of optical imaging with the deep penetration of ultrasound, providing non-invasive and radiation-free information on vascular morphology and function (such as blood oxygen saturation), making it particularly suitable for the imaging needs of peripheral vessels. This technology has broad clinical application prospects, including early diagnosis, disease monitoring, surgical navigation, and personalized treatment planning. For example, in the early intervention of diabetic foot and peripheral artery disease, photoacoustic imaging can help doctors detect lesions earlier and assess treatment effectiveness. Developing dedicated photoacoustic imaging devices for peripheral vessels can significantly improve the diagnostic level of vascular-related diseases, improve patients' quality of life, and has significant clinical significance and market value. Clinical needs include meeting the following requirements:

[0003] 1) Fast imaging speed: It not only improves subject compliance, but also significantly reduces artifacts caused by involuntary movements of the subject during the imaging process;

[0004] 2) Portable equipment: It can be pushed to the bedside in ordinary wards for use, and has a wider range of application scenarios;

[0005] 3) The equipment has high stability, ensuring no vibration and stable speed during the scanning process.

[0006] 4) It can perform precise imaging of multiple body parts and switch between different scanning modes for different parts of the human body, and perform precise imaging of the target area under guidance.

[0007] High-speed imaging necessitates larger probe sizes to acquire signals from a wider area and more angles in a single scan. Meanwhile, the demand for precise imaging of multiple body parts requires probes capable of extensive movement and high-precision scanning based on the contours of the target body area. Therefore, there is an urgent clinical need for a system that can stably support large-size scanning probes and facilitate rapid bedside imaging of multiple peripheral body parts.

[0008] Given the current technological background, there are already some systems for photoacoustic imaging of human peripheral blood vessels. These systems have the following advantages and disadvantages:

[0009] 1. Handheld Probe: During imaging, the operator holds the photoacoustic probe and scans the body surface. Advantages include flexible probe placement and a large adjustment range. Disadvantages include high skill requirements for the operator, susceptibility to interference from operator shaking, and limitations on probe size and weight. Furthermore, for large-area imaging, manual operation makes it difficult to guarantee imaging accuracy. Inconsistencies in operation between different operators, and even within the same operator, can lead to variations in imaging results, affecting image quality and subsequent analysis. (CN113057581A, CN118806238A, CN105167747A)

[0010] 2. Stacked 3D Translation Stage: This design utilizes stacked XYZ 3D scanning translation stages. In use, the 3D translation stage is placed on one side of the object to be imaged, and a cantilever structure extending from one side connects the photoacoustic probe to the stacked translation stages. The system is simple, but its drawback is that the center of gravity shifts during scanning, leading to decreased stability under heavy loads and large imaging areas. It is only suitable for driving relatively small scanning heads and cannot meet the needs of large scanning probes. Furthermore, one axis of the stack itself encroaches on scanning space, resulting in low space utilization.

[0011] 3. Multi-axis robotic arm: Using a robotic arm to replace a 3D translation stage to control the probe for scanning. The advantage is high scanning flexibility. However, achieving high 3D spatial scanning accuracy under heavy loads and large scanning ranges presents significant disadvantages such as high equipment and maintenance costs, and complex operation. Furthermore, due to the multi-axis flexibility of the robotic arm, complex programming control is still required to adapt to personalized imaging needs, demanding a high level of operator skill. (CN218651782U, CN118902383A)

[0012] 4. Gantry structures are also used in some industrial loading and unloading equipment, but they mainly place the crane on a movable beam to move heavy items suspended by traditional load-bearing cables. Due to the use of flexible cables, they cannot achieve real-time high-precision dynamic positioning under rapid movement, which does not meet the high-precision requirements of photoacoustic imaging for the scanning process of the probe. Summary of the Invention

[0013] To address the problems existing in the prior art, this invention proposes a photoacoustic three-dimensional imaging device and method for human peripheral blood vessels. It is portable and stable, enabling high-precision, high-resolution, non-invasive, and radiation-free vascular imaging of target areas in the human peripheral region. This compensates for the shortcomings of traditional imaging techniques in imaging peripheral microvessels and meets the clinical needs for early diagnosis and monitoring of vascular lesions.

[0014] One object of the present invention is to provide a photoacoustic three-dimensional imaging device for human peripheral blood vessels.

[0015] The 3D moving device includes an X-axis translation structure, a Y-axis translation structure, and a Z-axis translation structure mounted on a base plate. This structure features a spacious imaging operation space beneath the top beam within two support columns, used to house the first and second imaging water tanks. Different imaging water tanks can be used to accommodate imaging needs of different parts, both inside and below the tanks. The first imaging water tank is fixed to the base plate of the 3D moving device, which is fixed inside a light-shielding housing. The light-shielding housing is fixed to a lifting platform, and the imaging area is placed directly within the first imaging water tank. The bottom of the second imaging water tank is fixed to an imaging water tank lifting device, which is fixed to the base plate of the 3D moving device. The bottom of the second imaging water tank has openings covered with a light-transmitting and sound-transmitting flexible film. After adding coupling agent inside the second imaging water tank, the flexible film covers the imaging area, ensuring no airflow along the path from the probe to the imaging area for imaging. The imaging water tank lifting devices are fixed to both sides of the bottom of the second imaging water tank, ensuring they do not obstruct the openings or the imaging area. At this point, the imaging area is placed under the second imaging tank for imaging. The height of the second imaging tank is adjusted by a lifting device to accommodate the imaging needs of different imaging areas when imaging under the second imaging tank. The two types of imaging tanks allow for easy switching between imaging modes inside and below the tank; they also make better use of the ample imaging space under the top beam of the 3D moving device.

[0016] The photoacoustic three-dimensional imaging device for human peripheral blood vessels of the present invention includes: a three-dimensional moving device, a probe rotating device, a lifting platform, a probe, a signal processor, a data acquisition device, an imaging tank, an imaging tank lifting device, a laser, an optical fiber bundle, an upper camera positioning device, a contour measuring device, and a computing platform; wherein, the three-dimensional moving device is set on the lifting platform, and the area to be imaged is below the three-dimensional moving device, that is, below the top beam within the two pillars; the probe is mounted on the probe rotating device, and the probe rotating device is mounted on the translation structure of the three-dimensional moving device; the laser is connected to the light inlet of the optical fiber bundle, and the light outlet of the optical fiber bundle is fixed at the front end of the probe; the probe is connected to the signal processor and is acquired by the data acquisition device; the upper camera positioning device is located above the imaging tank, and the contour measuring device is located above or inside the imaging tank; the three-dimensional moving device, the probe rotating device, the laser, the upper camera positioning device, the contour measuring device, and the data acquisition device are respectively connected to the computing platform;

[0017] The three-dimensional imaging device has two imaging modes depending on the imaging location: the imaging mode inside the water tank and the imaging mode below the water tank. Corresponding to the two imaging modes, the imaging water tanks are the first imaging water tank and the second imaging water tank, respectively.

[0018] The imaging area is located on the base plate of the 3D moving device. The height of the 3D moving device and the imaging area is adjusted by a lifting platform to ensure the subject maintains a comfortable posture for imaging. The contour measurement device measures the contour of the imaging area, obtains the outer contour information of the imaging area, and transmits it to the computing platform. The upper camera positioning device acquires a planar image of the imaging area and transmits it to the computing platform. The operator determines the scanning area based on the planar image. The computing platform determines the movement path of the 3D moving device and the probe along the X and Y axes based on the scanning area. The movement speed along the X and Y axes is set to a predetermined value. The computing platform then uses the contour measurement device... The contour information of the acquired imaging area and the motion path of the 3D moving device along the X and Y axes are used to determine the motion speed and path along the Z axis, thereby ensuring that the imaging area is always within the effective imaging area of ​​the probe in the vertical direction. A laser emits a laser beam, which is uniformly irradiated onto the imaging area via an optical fiber bundle, generating a photoacoustic signal. In the water tank imaging mode, a first imaging water tank is used for imaging. The first imaging water tank is fixed to the base plate of the 3D moving device, and the imaging area, probe, and the light outlet of the optical fiber bundle are all located within the first imaging water tank. The probe is directly coupled to the imaging area through the acoustic coupling agent inside the first imaging water tank. Under the water tank... In imaging mode, a second imaging tank is used for imaging. The second imaging tank is fixed to an imaging tank lifting device, the bottom of which is fixed to the base plate of the 3D moving device. The bottom of the second imaging tank has openings covered with a light-transmitting and sound-transmitting flexible film. The imaging area is placed on the base plate of the 3D moving device, and the second imaging tank is placed on the imaging area. The height of the second imaging tank is adjusted by adjusting the imaging tank lifting device so that the light-transmitting and sound-transmitting flexible film at the bottom of the second imaging tank contacts the imaging area. The light outlets of the probe and fiber optic bundle are located inside the second imaging tank. The probe passes through the second imaging tank... The acoustic coupling agent and the light- and sound-transmitting flexible film are coupled to the imaging part; the imaging part is covered with acoustic coupling agent to ensure adhesion to the light- and sound-transmitting flexible film, avoiding air between the probe and the imaging part, which would affect the imaging effect; the probe receives photoacoustic signals, which are processed by the signal processor, then collected by the data acquisition unit, and transmitted to the computing platform to reconstruct two-dimensional and three-dimensional photoacoustic images; in both the imaging mode inside the water tank and the imaging mode under the water tank, when the imaging part is not horizontal, the probe angle is adjusted by the probe rotation device, and the probe is rotated to image the left and right sides of the imaging part, further increasing the imaging range.

[0019] Furthermore, the present invention also includes a light-shielding shell, within which the three-dimensional moving device, imaging stage, probe, and the ends of the fiber bundle are all located. In the in-tank imaging mode, the first imaging tank is fixed to the base plate of the three-dimensional moving device, the three-dimensional moving device is fixed inside the light-shielding shell, and the light-shielding shell is fixed to the lifting platform; in the under-tank imaging mode, the second imaging tank is fixed to the imaging tank lifting device, the imaging tank lifting device is fixed to the base plate of the three-dimensional moving device, the three-dimensional moving device is fixed inside the light-shielding shell, and the light-shielding shell is fixed to the lifting platform.

[0020] For different imaging areas, corresponding imaging modes are selected. For imaging areas such as hands and feet that can be directly placed into the imaging tank, the in-tank imaging mode is selected; for imaging areas such as upper arms, legs, and abdomen that are not easily placed into the imaging tank, the under-tank imaging mode is selected. Since the imaging areas such as hands, arms, feet, and legs are not completely horizontal, and the optimal depth range of the probe imaging is limited, it is necessary to image based on the contour of the imaging area as much as possible. Therefore, this invention has two positioning systems. One is that the subject measures the imaging area before or during imaging using a contour measuring device to determine the contour information of the imaging areas such as hands, arms, feet, and legs. The other is an upper camera positioning device, the purpose of which is to take pictures of the selected scanning range after the subject places the imaging areas such as hands, arms, feet, and legs in the imaging area. The upper camera positioning system and the contour measuring device control the three-dimensional moving device to scan according to the set range. The probe has an effective imaging area of ​​8cm on the horizontal plane and 3~5cm on the Z-axis. If the imaging object is out of the effective imaging area, the imaging effect will be worse. The X-axis and Y-axis imaging ranges obtained by the camera positioning device on the computing platform, and the total imaging time, can be obtained by calculating the X-axis and Y-axis movement speeds of 1 mm / s to 10 mm / s. Then, based on the contour information obtained by the contour measurement device and the total imaging time, the initial position and movement speed of the Z-axis are determined. This ensures that the distance between the imaging area and the probe remains within the set range throughout the acquisition process.

[0021] The data acquisition unit uses a multi-channel parallel high-frequency data acquisition unit.

[0022] The upper camera positioning device uses a camera; the contour measurement device uses an optical measurement device or an ultrasonic measurement device; the outer contour of the imaging area is measured before or during the scanning imaging process, and the measurement data is processed by the computing platform to control the motion path of the probe; the motion path is planned before scanning or adjusted in real time during scanning to ensure that the distance from the probe to the imaging area is within the set range.

[0023] The invention also includes a signal processor. The probe is connected to the data acquisition unit via the signal processor. The probe receives photoacoustic signals, which are amplified by the signal processor, acquired by the data acquisition unit, and transmitted to the computing platform.

[0024] One objective of this invention is to provide a photoacoustic three-dimensional imaging method for human peripheral blood vessels.

[0025] The photoacoustic three-dimensional imaging method for human peripheral blood vessels of the present invention includes the following steps:

[0026] 1) The three-dimensional moving device and the imaging tank are located on the lifting platform. The height of the three-dimensional moving device, the imaging part and the imaging tank are adjusted by the lifting platform as a whole so that the subject can maintain a more comfortable posture for imaging.

[0027] 2) The contour measurement device performs contour measurement on the imaging area, obtains the contour information of the imaging area, and transmits it to the computing platform;

[0028] 3) The upper camera positioning device acquires a planar image of the imaging area and sends it to the computing platform. The operator determines the scanning area based on the planar image. The computing platform determines the movement path of the probe driven by the three-dimensional moving device on the X-axis and Y-axis based on the scanning area. The movement speed on the X-axis and Y-axis is a set value.

[0029] 4) The computing platform determines the movement speed and movement path of the Z-axis based on the contour information of the imaging part obtained by the contour measurement device and the movement path of the three-dimensional moving device on the X and Y axes, so that the three-axis composite movement of the three-dimensional moving device is consistent with the contour information of the imaging part, thereby ensuring that the distance from the probe to the imaging part is within the set range.

[0030] 5) The laser emits a laser beam, which is uniformly irradiated onto the imaging area through the fiber bundle, generating a photoacoustic signal;

[0031] 6) In the water tank imaging mode: The first imaging water tank is fixed on the base plate of the three-dimensional moving device. The imaging part, the probe and the light outlet of the fiber bundle are all located in the first imaging water tank. The probe is directly coupled to the imaging part through the acoustic coupling agent inside the first imaging water tank.

[0032] Alternatively, in the underwater imaging mode: the second imaging tank is placed on an imaging tank lifting device, which is fixed to the base plate of the three-dimensional moving device. The bottom of the second imaging tank has openings covered with a light- and sound-transmitting flexible film. The height of the second imaging tank is adjusted by adjusting the imaging tank lifting device, ensuring that the light- and sound-transmitting flexible film at the bottom of the second imaging tank contacts the imaging area. The light outlets of the probe and fiber bundle are located inside the second imaging tank. The probe couples with the imaging area through the acoustic coupling agent and the light- and sound-transmitting flexible film within the second imaging tank. The imaging area is covered with acoustic coupling agent to ensure adhesion to the light- and sound-transmitting flexible film, preventing air from the probe from affecting the imaging effect.

[0033] 7) The probe receives photoacoustic signals, which are processed by the signal processor, then collected by the data acquisition unit and transmitted to the computing platform to reconstruct two-dimensional and three-dimensional photoacoustic images;

[0034] 8) In both the in-tank imaging mode and the under-tank imaging mode, when the imaging area is not horizontal, the angle of the probe is adjusted by the probe rotation device, and the probe is rotated to image the left and right sides of the imaging area, thereby further increasing the imaging range.

[0035] Advantages of this invention:

[0036] This invention provides detailed information on vascular structure and blood flow dynamics through the high resolution and functional monitoring capabilities of photoacoustic imaging, facilitating early identification and treatment efficacy evaluation of common lesions such as diabetic foot and peripheral artery disease. Furthermore, the mechanical system employed in this invention can support a high-quality detection front-end and ensure stable operation, resulting in superior photoacoustic imaging outcomes. This invention also holds promise for improving device portability, reducing development costs, and enabling its widespread application in clinical practice and community healthcare, thereby enhancing disease management.

[0037] 1. Highly stable and precise scanning imaging method: High-performance probes plus auxiliary components such as preamplifier modules greatly increase the weight of the scanning head. The gantry-type three-dimensional moving device scanning architecture proposed in this design can achieve stable three-dimensional motion under heavy load and achieve highly stable scanning at a relatively low cost.

[0038] 2. Multiple Imaging Modes Facilitating Clinical Application: The unique structural characteristics of the 3D moving device allow for convenient placement of hands, arms, feet, and legs in the through-space beneath the crossbeam, making it particularly suitable for peripheral vascular imaging of multiple body parts. Imaging areas where hands and feet can be placed directly inside the imaging tank can be imaged using the in-tank imaging mode. For areas such as the upper arm, legs, and abdomen that are not suitable for placement inside the imaging tank, the under-tank imaging mode is selected. The lifting platform allows for easy switching between imaging at different heights for body parts such as hands and feet. An imaging bed can also be added to accommodate imaging needs for areas like the legs, expanding the device's applicability and enabling it to efficiently serve various clinical testing needs and research environments.

[0039] 3. The gantry-type 3D moving device provides sufficient space for switching between multiple photoacoustic imaging modes while ensuring the stability of the scanning probe under heavy load, thus improving the accuracy of photoacoustic imaging. However, the space provided by the gantry is relatively limited. This invention, through the arrangement of the imaging water tank and its lifting structure, ensures that the switching of imaging modes can be accommodated within a limited space, thereby making it suitable for the gantry layout. Therefore, the two major technical means of the gantry layout and the water tank layout work together and support each other, realizing the ability to switch between multiple clinical modes on the basis of stable support. It is suitable for clinical scenarios that require precise photoacoustic detection and continuous switching of detection modes.

[0040] 4. Research and Application Potential: The 3D moving device, which drives a complex probe and scanner, eliminates the influence of subjective human factors present in handheld probe operation, reducing operational difficulty. Furthermore, the use of two camera positioning devices allows for the determination of the X, Y, and Z axes imaging path of the 3D moving device via a computational platform, achieving full automation of the scanning process and ensuring test repeatability. This enables better comparison of imaging results before and after treatment to study chronic diseases and the effects of drug or surgical treatments.

[0041] Scope of Application: Scenarios requiring precise vascular assessment, assisting clinicians and researchers in exploring the prevention, diagnosis, and treatment of vascular diseases. 1. Clinical Diagnosis: Used for the detection and assessment of peripheral artery disease, aiding in treatment planning. Detecting microvascular complications in diabetic patients, such as diabetic foot, for early intervention and management. Assessing venous dysfunction, such as varicose veins or thrombosis, for pre- and post-operative evaluation. 2. Vascular Function Assessment: Performing tissue metabolic function tests, measuring blood oxygen saturation, and assessing vascular function and circulatory status. Identifying vascular stenosis or dysfunction through functional imaging. 3. Chronic Disease Management: Used for long-term monitoring of vascular health in patients with chronic diseases, dynamically assessing disease progression. 4. Research and Development: Used to study the biological mechanisms of vascular lesions, supporting the development of new therapies. Evaluating and validating the effectiveness of novel drugs or treatment technologies. 5. Preventive Health Checks: Used for vascular health screening in healthy individuals, identifying potential risks early. Attached Figure Description

[0042] Figure 1 This is a structural block diagram of an embodiment of the photoacoustic three-dimensional imaging device for human peripheral blood vessels of the present invention;

[0043] Figure 2 This is a front view of an embodiment of the photoacoustic three-dimensional imaging device for human peripheral blood vessels of the present invention;

[0044] Figure 3 This is a schematic diagram of hand imaging, representing an embodiment of the photoacoustic three-dimensional imaging device for human peripheral blood vessels according to the present invention;

[0045] Figure 4 This is a schematic diagram of foot imaging, representing an embodiment of the photoacoustic three-dimensional imaging device for human peripheral blood vessels according to the present invention.

[0046] Figure 5 This is a schematic diagram of the positioning principle of the contour measurement device for foot imaging, which is an embodiment of the photoacoustic three-dimensional imaging device for human peripheral blood vessels of the present invention.

[0047] Figure 6 This is a schematic diagram of the actual operation of the in-water tank imaging mode of an embodiment of the photoacoustic three-dimensional imaging device for human peripheral blood vessels of the present invention.

[0048] Figure 7 This is a schematic diagram of actual operation and a representative result diagram of the underwater imaging mode of an embodiment of the photoacoustic three-dimensional imaging device for human peripheral blood vessels of the present invention.

[0049] Figure 8 These are representative results of the hand (left) and foot (right) of the photoacoustic three-dimensional imaging device for human peripheral blood vessels of the present invention; Detailed Implementation

[0050] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0051] like Figure 1 and 2 As shown, the photoacoustic three-dimensional imaging device for human peripheral blood vessels in this embodiment includes: a three-dimensional moving device, a probe rotating device, a lifting platform, a probe, a signal processor, a data acquisition unit, first and second imaging tanks, an imaging tank lifting device, a laser, an optical fiber bundle, an upper camera positioning device, a contour measuring device, and a computing platform.

[0052] Because the photoacoustic signal received by the probe is relatively weak, it needs to be amplified before acquisition. To minimize signal loss, the best approach is to amplify the photoacoustic signal immediately after it is received by the probe. Furthermore, the shorter the distance between the probe and the signal processor, the better. In this invention, both the probe and the signal processor are fixed on a three-dimensional moving device, with a connection line of only 15cm between them, effectively reducing transmission loss. However, in this case, the combined mass of the probe and signal processor is relatively large, approximately 5kg. To maintain stable imaging quality, the system needs to stably move this mass of probe and signal processor components.

[0053] Therefore, this invention addresses the stability issue of the system under large-mass probes and signal processors by employing a special three-dimensional moving device. The advantages of this device are rationally utilized through the interchangeable use of the first and second imaging tanks, expanding its application scope. Different imaging tanks are used to accommodate imaging needs at different locations, both inside and at the bottom of the tank. The first imaging tank is directly fixed to the base plate of the three-dimensional moving device, which is fixed inside a light-shielding shell. The light-shielding shell is fixed to a lifting platform, allowing the imaging area to be directly placed inside the first imaging tank. The bottom of the second imaging tank is fixed to an imaging tank lifting device, which is fixed to the base plate of the three-dimensional moving device. The second imaging tank has openings at its bottom, covered with a light-transmitting and sound-transmitting flexible film. After adding coupling agent inside the second imaging tank, the film covers the imaging area, ensuring no airflow along the path from the probe to the imaging area for imaging. The imaging tank lifting devices are fixed to both sides of the bottom of the second imaging tank, preventing obstruction of the openings and the imaging area. In this case, the imaging area is placed at the bottom of the second imaging tank for imaging. The height of the second imaging tank is adjusted using an imaging tank lifting device to accommodate the imaging needs of different imaging areas when imaging is performed below the imaging tank. The two imaging tank configurations allow for easy switching between imaging modes inside and below the imaging tank. It also better utilizes the ample imaging space beneath the top beam of the 3D moving device.

[0054] The system comprises a three-dimensional moving device housed within a light-shielding shell on the lifting platform. The imaging area is located below the three-dimensional moving device, specifically below the top beam within the two support pillars. A probe is mounted on a probe rotation device, which in turn is mounted on the translational structure of the three-dimensional moving device. A laser is connected to the input port of a fiber optic bundle (using a 1 / 10 splitter fiber), and the output port of the fiber optic bundle is fixed to the front end of the probe. The probe is connected to a data acquisition unit via a signal processor. An upper camera positioning device is located above the imaging tank, and a contour measurement device is located above or inside the imaging tank. The three-dimensional moving device, probe rotation device, laser, upper camera positioning device, contour measurement device, and data acquisition unit are all connected to a computing platform. The upper camera positioning device uses a camera; the contour measurement device uses either the optical method of a camera or the ultrasonic method of an ultrasonic probe. The light-transmitting and sound-transmitting flexible film is made of PVC; water is used as the acoustic coupling agent inside the tank, and medical ultrasonic coupling agent is used for coupling the light-transmitting and sound-transmitting flexible film with the imaging area.

[0055] The three-dimensional imaging device has two imaging modes depending on the imaging location: in-water tank imaging mode and underwater tank imaging mode.

[0056] The imaging area and imaging tank are located on the three-dimensional moving device. The height of the three-dimensional moving device, the imaging area, and the imaging tank are adjusted as a whole by a lifting platform to allow the subject to maintain a relatively comfortable posture for imaging. Figure 3 As shown, the lifting platform rises during hand imaging, as... Figure 4 As shown, the lifting platform is at the lowest point when imaging the feet; as Figure 5 As shown, the contour measurement device measures the contour of the imaging area, obtains the contour information of the imaging area, and transmits it to the computing platform; the upper camera positioning device acquires a planar image of the imaging area and transmits it to the computing platform. The operator determines the scanning area based on the planar image. The computing platform determines the movement path of the probe driven by the three-dimensional moving device along the X and Y axes based on the scanning area. The movement speed of the X and Y axes is a set value of 1 mm / s. The X and Y axes are located on the horizontal plane, and the Z axis is perpendicular to the horizontal plane. Based on the contour information of the imaging area obtained by the contour measurement device and the movement path of the three-dimensional moving device along the X and Y axes, the computing platform determines the movement speed and movement path of the Z axis, so that the combined movement path of the three-axis moving device is consistent with the contour information of the imaging area, thereby ensuring that the imaging area is always within the effective imaging area of ​​the probe in the vertical direction. The laser emits a laser with a wavelength of 1024 nm. In the experiment, a laser frequency of 10 Hz and an energy of 500 mJ are selected. The laser is uniformly irradiated onto the imaging area through a 1 / 10 fiber optic bundle, generating a photoacoustic signal. In the imaging mode in the water tank, as shown... Figure 6As shown, imaging is performed using a first imaging tank, which is mounted on the base of a 3D moving device. The 3D moving device is fixed inside a light-shielding housing, which is fixed to a lifting platform. The imaging area, probe, and the light outlet of the fiber optic bundle are all located inside the first imaging tank. The probe is directly coupled to the imaging area through a coupling agent inside the first imaging tank. In the imaging mode under the tank, as shown... Figure 7 As shown, imaging is performed using a second imaging tank, which is fixed to an imaging tank lifting device. The lifting device is installed at the bottom of a three-dimensional moving device, which is fixed inside a light-shielding shell. The light-shielding shell is fixed to a lifting platform, and the second imaging tank is placed on the imaging area. The height of the second imaging tank is adjusted by adjusting the lifting device so that the light-transmitting and sound-transmitting flexible film at the bottom of the tank contacts the imaging area. The light outlets of the probe and fiber bundle are located inside the second imaging tank. The probe couples to the imaging area through a coupling agent in the tank and the light-transmitting and sound-transmitting flexible film. The imaging area is covered with coupling agent to ensure adhesion to the film and prevent air from affecting the imaging effect. For example, when imaging an arm, an acoustic coupling agent, such as water, is first injected into the second imaging tank, and then an acoustic coupling agent, such as an ultrasonic coupling agent, is applied to the imaging area of ​​the arm. The height of the second imaging tank is adjusted using the imaging tank lifting device. The arm is then aligned with the light- and sound-transparent film at the bottom of the second imaging tank. After the probe is submerged in the water and the distance from the arm meets the imaging requirements, the laser is activated for imaging. The probe receives photoacoustic signals, which are amplified by the signal processor, acquired by the data acquisition unit, and transmitted to the computing platform to reconstruct two-dimensional and three-dimensional photoacoustic images. In both the in-tank imaging mode and the submerged imaging mode, when the imaging area is not horizontal, the probe angle is adjusted using the probe rotation device. The probe is rotated to image the left and right sides of the imaging area, further increasing the imaging range.

[0057] The probe consists of 256 self-focusing ultrasonic elements for receiving photoacoustic signals. Each ultrasonic element measures 16 × 0.265 mm and is arranged with a 0.3 mm gap between the centers of two elements. The total length of the probe is 80 mm, the self-focusing radius is 40 mm, and the optimal imaging position is 40 ± 10 mm from the probe.

[0058] The specific form of the three-dimensional moving device includes: a support column, a top beam, a slide rail, a groove, a slider, and a translation structure. Two support columns are placed symmetrically on both sides, and their tops are connected by the top beam. The bottom ends of the two support columns are each located on a slide rail along the X-axis, allowing the two columns to move back and forth along the X-axis, forming an X-axis translation structure. A groove along the Y-axis is formed on the surface of the top beam, and the slider moves along the Y-axis groove, forming a Y-axis translation structure. A translation structure along the Z-axis is set on the slider in the groove, allowing it to move up and down along the Z-axis, forming a Z-axis translation structure, and also moving left and right along the Y-axis within the groove. All three axes of the three-dimensional moving device are controlled by ball screws. For the X-axis translation structure, in addition to using ball screws, synchronous belts or rack and pinion drives can be used. For the Y-axis translation structure, in addition to ball screws, synchronous belts or linear motors can also be used. For the Z-axis translation structure, in addition to ball screws, synchronous belts or linear motors can also be used.

[0059] The reconstructed photoacoustic image is as follows Figure 8 As shown, the result is a series of cross-sectional images of the imaging sites acquired by the probe in the Z-axis section during scanning along the X-axis. The obtained cross-sectional images are stitched together into a three-dimensional volume and then projected onto the xy-plane using the maximum amplitude projection method to obtain a photoacoustic image. Figure 8 The left image shows the photoacoustic imaging result of the hand. Figure 8 The right image shows the photoacoustic imaging result of the foot.

[0060] Finally, it should be noted that the purpose of disclosing the embodiments is to help further understand the present invention. However, those skilled in the art will understand that various substitutions and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the present invention should not be limited to the content disclosed in the embodiments, and the scope of protection of the present invention is defined by the claims.

Claims

1. A photoacoustic three-dimensional imaging device for human peripheral blood vessels, characterized in that, The imaging device includes: a three-dimensional moving device, a probe, a data acquisition unit, an imaging tank, a laser, an optical fiber bundle, an upper camera positioning device, a contour measurement device, and a computing platform; wherein, the probe is mounted on the translation structure of the three-dimensional moving device; the laser is connected to the light inlet of the optical fiber bundle, and the light outlet of the optical fiber bundle is fixed at the front end of the probe; the probe is connected to the data acquisition unit; the upper camera positioning device is located above the imaging tank, and the contour measurement device is located above or inside the imaging tank; the three-dimensional moving device, the laser, the upper camera positioning device, the contour measurement device, and the data acquisition unit are respectively connected to the computing platform; The three-dimensional imaging device has two imaging modes depending on the imaging location: the imaging mode inside the water tank and the imaging mode below the water tank. Corresponding to the two imaging modes, the imaging water tank adopts the first imaging water tank and the second imaging water tank respectively. The contour measurement device measures the contour of the imaging area, obtains the outer contour information of the imaging area, and transmits it to the computing platform; the upper camera positioning device acquires a planar image of the imaging area and transmits it to the computing platform, determines the scanning area based on the planar image, and the computing platform determines the movement path of the probe driven by the three-dimensional moving device along the X and Y axes based on the scanning area; the computing platform determines the movement speed and movement path along the Z axis based on the outer contour information; the laser emits a laser beam, which is uniformly irradiated onto the imaging area through an optical fiber bundle, generating a photoacoustic signal; the probe receives the photoacoustic signal, which is collected by the data acquisition device and transmitted to the computing platform to reconstruct two-dimensional and three-dimensional photoacoustic images; The three-dimensional moving device includes: a support column, a top beam, a slide rail, a slide groove, a slider, and a translation structure; wherein, two support columns are placed symmetrically on both sides, and the top ends of the two support columns are connected by the top beam; the bottom ends of the two support columns are respectively located on a slide rail along the X-axis, so that the two support columns can move back and forth along the X-axis, forming an X-axis translation structure; the surface of the top beam has a slide groove along the Y-axis, and the slider moves along the slide groove along the Y-axis to form a Y-axis translation structure; a translation structure along the Z-axis is set on the slider on the slide groove, and the translation structure can move up and down along the Z-axis to form a Z-axis translation structure, and can also move left and right along the Y-axis within the slide groove; It also includes a lifting platform; the three-dimensional moving device, the imaging part and the imaging tank are located on the lifting platform, and the height of the three-dimensional moving device, the imaging part and the imaging tank are adjusted as a whole by the lifting platform; in the imaging mode inside the tank, the first imaging tank is located on the base plate of the three-dimensional moving device, and the imaging part is located inside the first imaging tank; in the imaging mode below the tank, the second imaging tank is fixed on the imaging tank lifting device, the imaging tank lifting device is installed on the base plate of the three-dimensional moving device, and the imaging part is located below the second imaging tank and on the base plate of the three-dimensional moving device.

2. The imaging device according to claim 1, characterized in that, It also includes a light-shielding shell, in which the ends of the three-dimensional moving device, the imaging tank, the probe, and the fiber bundle are all located.

3. The imaging device according to claim 1 or 2, characterized in that, The contour measuring device uses an optical or ultrasonic measuring method to measure the outer contour of the imaging area before or during scanning imaging. The measurement data is processed by a computing platform and used to control the motion path of the probe. The motion path is planned before scanning or adjusted in real time during scanning so that the distance from the probe to the imaging area is within a set range.

4. The imaging device according to claim 1, characterized in that, It also includes a signal processor. The probe is connected to the data acquisition unit via the signal processor. The probe receives photoacoustic signals, which are amplified by the signal processor and then collected by the data acquisition unit and transmitted to the computing platform.

5. The imaging device according to claim 1, characterized in that, It also includes a probe rotation device, on which the probe is mounted. The probe rotation device is mounted on the translation structure of the three-dimensional moving device and is connected to the computing platform. In two imaging modes, the probe angle is adjusted by the probe rotation device to image the left and right sides of the imaging area.

6. An imaging method for the photoacoustic three-dimensional imaging device for human peripheral blood vessels according to claim 1, characterized in that, The imaging method includes the following steps: 1) The three-dimensional moving device and the imaging tank are located on the lifting platform. The height of the three-dimensional moving device, the imaging part and the imaging tank are adjusted as a whole by the lifting platform. 2) The contour measurement device performs contour measurement on the imaging area, obtains the contour information of the imaging area, and transmits it to the computing platform; 3) The upper camera positioning device acquires a planar image of the imaging area and sends it to the computing platform. The scanning area is determined based on the planar image. The computing platform determines the movement path of the probe driven by the three-dimensional moving device on the X-axis and Y-axis based on the scanning area. The movement speed on the X-axis and Y-axis is a set value. 4) The computing platform determines the movement speed and movement path of the Z-axis based on the contour information of the imaging part obtained by the contour measurement device and the movement path of the three-dimensional moving device on the X and Y axes, so that the three-axis composite movement of the three-dimensional moving device is consistent with the contour information of the imaging part, and the distance from the probe to the imaging part is within the set range. 5) The laser emits a laser beam, which is uniformly irradiated onto the imaging area through the fiber bundle, generating a photoacoustic signal; 6) The three-dimensional imaging device has two imaging modes depending on the imaging part: the imaging mode inside the water tank and the imaging mode below the water tank. Corresponding to the two imaging modes, the imaging water tank adopts the first imaging water tank and the second imaging water tank respectively. 7) The probe receives photoacoustic signals, which are processed by the signal processor, then collected by the data acquisition unit and transmitted to the computing platform to reconstruct two-dimensional and three-dimensional photoacoustic images; 8) In both imaging modes, when the imaging area is not horizontal, the probe angle is adjusted by the probe rotation device, and the probe is rotated to image the left and right sides of the imaging area.

7. The imaging method according to claim 6, characterized in that, Select the appropriate imaging mode for different imaging areas: for imaging areas that can be easily placed in the imaging tank, select the in-tank imaging mode; for imaging areas that are not easy to place in the imaging tank, select the submerged imaging mode.

8. The imaging method according to claim 7, characterized in that, Imaging mode in the water tank: The first imaging water tank is installed on the base plate of the three-dimensional moving device. The imaging part, the probe and the light outlet of the fiber bundle are all located in the first imaging water tank. The probe is coupled to the imaging part through the acoustic coupling agent inside the first imaging water tank.

9. The imaging method according to claim 7, characterized in that, In the underwater imaging mode: the second imaging tank is fixed on the imaging tank lifting device, which is installed on the base plate of the three-dimensional moving device. The bottom of the second imaging tank has holes covered with a light-transmitting and sound-transmitting flexible film. The height of the second imaging tank is adjusted by adjusting the imaging tank lifting device so that the light-transmitting and sound-transmitting flexible film at the bottom of the second imaging tank contacts the imaging part. The light outlet of the probe and the fiber bundle is located inside the second imaging tank. The probe is coupled to the imaging part through the acoustic coupling agent in the second imaging tank and the light-transmitting and sound-transmitting flexible film. The imaging part is covered with acoustic coupling agent to adhere to the light-transmitting and sound-transmitting flexible film.

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