Endoscopic probe for photoacoustic tomography of cavity side walls

Abstract

The present invention relates to an endoscopic probe for photoacoustic tomography of cavity side walls, characterized by comprising a hollow tubular probe housing with a closed front end; N acoustic wave receiving windows and M laser output windows formed on the side wall of the tubular probe housing; an array of linear laser output ports connected to a pluggable optical fiber connector via an optical fiber bundle; and an ultrasonic transducer array connected to a multi-channel signal connector via a signal harness. The present invention employs a method of arranging array transducers and array laser outputs on the side wall of the probe, eliminating the need for a reflector. The probe is less than 2 centimeters in size and can be placed in close proximity to the prostate through the rectum for photoacoustic imaging of the prostate, or in close proximity to the inner wall of the rectum for photoacoustic imaging of the inner wall of the rectum. The endoscopic probe provided by the present invention, combined with a photoacoustic imaging system host, utilizes photoacoustic endoscopic imaging technology to perform real-time transrectal prostate imaging and rectal imaging, achieving ideal imaging results.

Description

Technical Field

[0001] The invention relates to an endoscopic probe which is specially used for photoacoustic tomography of cavity side walls and can be used for the examination of prostate cancer and colorectum. Background Art

[0002] Prostate cancer is a common malignant tumor of the genitourinary system in elderly men. Its incidence and mortality rate rank second and fifth among male malignant tumors worldwide, respectively. It ranks first and third, respectively, among men in Europe and the United States, and sixth and seventh, respectively, among men in China. In recent years, driven by the aging of China's population, the incidence and mortality of prostate cancer have shown a significant upward trend, increasing the burden of the disease. Screening high-risk individuals for prostate cancer and early diagnosis and treatment of patients are crucial to improving the cure rate of prostate cancer.

[0003] Existing commonly used screening methods, such as PSA and ultrasound, have a low cancer detection rate. Among them, PSA has a misdiagnosis rate of nearly 1 / 4. Simple ultrasound imaging (USI) only reflects the mechanical properties of tissues through the image contrast provided by changes in acoustic impedance. Photoacoustic imaging has rich optical contrast and can provide biological functions or physiological parameters, such as hemoglobin oxygen saturation, metabolic rate, and the relative concentrations of water and lipids. Photoacoustic imaging technology combines acoustic and optical imaging methods to provide richer tissue and functional information for pathological analysis of various diseases.

[0004] There are currently several photoacoustic probe designs, but none of these probes can perform well on the detection of the prostate or rectum. Some photoacoustic probes designed for in vitro imaging (such as patent applications with publication numbers JP2018183614A, WO2013067304A1, US20230033766A1, and WO2014116705A1) are limited by their design structure and size and cannot image the side walls of the colorectum. The characteristics of these photoacoustic probes are that the laser output and imaging field of view are both at the front end (head) of the probe, and they cannot enter the intestine to image the side walls of the intestine and the prostate. Some patent designs (such as the patent application with publication number CN12493997A) are single-point imaging, which requires a rotating catheter to image the inner wall in a circle, which limits the imaging speed and makes it difficult to achieve real-time imaging. Moreover, since the prostate is only located on one side of the outer wall of the colorectum, single-point rotation or circular array probe imaging modes are not suitable for prostate examination. Summary of the Invention

[0005] The purpose of the present invention is to provide an endoscopic probe which can be inserted into the body through a natural cavity and perform tomographic imaging of the inner wall of the cavity.

[0006] In order to achieve the above-mentioned purpose, the technical solution of the present invention is to provide an endoscopic probe for photoacoustic tomography of cavity side walls, which is characterized in that it includes a tubular probe shell with a closed front end and a hollow interior, and the diameter of the tubular probe shell matches the diameter of the natural cavity to be inserted; N sound wave receiving windows and M laser output windows are opened on the side wall of the tubular probe shell, N≥1, M≥1, wherein the N sound wave receiving windows are used for N ultrasonic transducer arrays located in the tubular probe shell to receive sound waves, and the M laser output windows are used for M array linear laser output ports located in the tubular probe shell to output lasers; the array linear laser output ports are connected to a pluggable optical fiber connector via an optical fiber bundle; and the ultrasonic transducer array is connected to a multi-channel signal connector via a signal harness.

[0007] Preferably, the diameter of the front end of the tubular probe housing is 0.1 cm-5 cm.

[0008] Preferably, the ultrasonic transducer array and the array linear laser output port are placed parallel to the side wall of the tubular probe housing.

[0009] Preferably, the array linear laser output port is in close proximity to the ultrasonic transducer array.

[0010] Preferably, the array linear laser output port outputs surface laser light in the form of a rectangular surface, a fan-shaped surface or a trapezoidal surface.

[0011] Preferably, the ultrasonic transducer array is a linear array, a convex array, a concave array or a semi-circular array.

[0012] Preferably, the number of channels included in a single ultrasonic transducer array is greater than 2.

[0013] Preferably, an optical fiber splitting and fixing device is provided in the tubular probe housing, and the optical fiber splitting and fixing device separates the several thin optical fibers contained in the optical fiber bundle and arranges them into a line and then fixes them on the array linear laser output port.

[0014] Preferably, the pluggable fiber optic connector includes a body, which includes two coaxial open-loop hollow cylinders of different sizes, each open-loop hollow cylinder is respectively connected to two clamping fins for controlling its size, and there is a coupling groove between the two open-loop hollow cylinders; the inner ring openings of the two open-loop hollow cylinders correspond to the sizes of the laser output head and the optical fiber bundle input head, respectively, and through the clamping fins, the two open-loop hollow cylinders clamp and fix the laser output head and the optical fiber bundle respectively.

[0015] The present invention utilizes an array transducer and array laser output arrayed on the sidewall of the probe, eliminating the need for reflectors. The probe, measuring less than 2 centimeters, can be placed against the prostate through the rectum for photoacoustic imaging, as well as against the rectal inner wall. The endoscopic probe provided by the present invention, combined with a photoacoustic imaging system, utilizes photoacoustic endoscopic imaging technology to perform real-time transrectal prostate imaging and rectal imaging. This provides excellent imaging results, enabling better screening for pathologies such as prostate cancer, facilitating early detection of cancer, and significantly advancing the diagnosis and treatment of prostate cancer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the photoacoustic endoscopy probe structure (external top view);

[0017] Figure 2 Schematic diagram of the photoacoustic endoscopy probe structure (internal cross-sectional view);

[0018] Figure 3 The diagram shows three arrangements of the transducer array and the laser output port.

[0019] Figure 4A The appearance structure of the pluggable optical fiber connector is shown;

[0020] Figure 4B is a cross-sectional view of a pluggable optical fiber connector;

[0021] Figure 5 The imaging results using the probe of the present invention are shown. DETAILED DESCRIPTION

[0022] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0023] Combine Figure 1 and Figure 2 The photoacoustic endoscopic probe disclosed in an embodiment of the present invention includes a hollow tubular probe housing 10 with a closed front end. The tubular probe housing 10 has a suitable diameter for insertion into an animal or human body through a natural cavity. In this embodiment, the diameter of the front end of the tubular probe housing 10 ranges from 0.1 cm to 5 cm.

[0024] The sidewall of the tubular probe housing 10 is provided with N acoustic wave receiving windows and M laser output windows, where N ≥ 1 and M ≥ 1. The N acoustic wave receiving windows are used by the N ultrasonic transducer arrays 21 within the tubular probe housing 10 to receive acoustic waves, while the M laser output windows are used by the M array linear laser output ports 31 within the tubular probe housing 10 to output laser light.

[0025] In such Figure 1 and Figure 2 In the illustrated embodiment, an ultrasonic transducer array 21 and an array of linear laser output ports 31 are positioned parallel to the sidewall of the tubular probe housing 10, with the array of linear laser output ports 31 in close proximity to the ultrasonic transducer array 21. Correspondingly, a window for receiving sound waves and a window for outputting laser light are formed on the sidewall of the tubular probe housing 10.

[0026] In the present invention, the number and arrangement of the ultrasonic transducer array 21 and the array linear laser output port 31 are not limited to Figure 1 and Figure 2 The way shown, Figure 3 Three different settings are given. Figure 3 (a) in the figure shows how Figure 1 as well as Figure 2 The way shown, Figure 3 (b) in FIG. 1 shows a configuration in which two arrays of ultrasonic transducer arrays 21 sandwich one array of linear laser output ports 31. Figure 3 Figure (c) illustrates an arrangement where two arrays of linear laser output ports 31 sandwich one array of ultrasonic transducer arrays 21. Depending on the number and position of the ultrasonic transducer arrays 21 and arrays of linear laser output ports 31, the number and position of the acoustic wave receiving windows and laser output windows must also be modified accordingly, which will not be further detailed here.

[0027] The endoscopic probe disclosed in the present invention outputs a surface laser through the array linear laser output port 31. The ultrasonic transducer array 21 receives photoacoustic signals from objects scanned by this laser surface. The laser surface serves as the effective imaging surface of the endoscopic probe disclosed in the present invention. In this embodiment, the surface laser output through the array linear laser output port 31 can be designed to have a rectangular, sector-shaped, or trapezoidal surface. The ultrasonic transducer array 21 in this embodiment is not limited to a linear array; it can also be a convex, concave, or semi-circular array. A single ultrasonic transducer array 21 can contain more than two channels.

[0028] The array linear laser output port 31 is connected to a pluggable fiber optic connector 33 via a fiber bundle 32. The fiber bundle 32 contains several thin optical fibers, which are separated and arranged into a line in a fiber splitter fixture 34 located within the tubular probe housing 10 and then fixed to the array linear laser output port 31. The fiber splitter fixture 34 guides the individual optical fibers to the array linear laser output port 31 while maintaining a small bending radius.

[0029] Combine Figure 4A as well as Figure 4B In this embodiment, the pluggable fiber optic connector 33 includes a body 336, which further includes two coaxial open-loop hollow cylinders 331 of different sizes, with a coupling groove 335 between the two open-loop hollow cylinders 331. The inner ring openings of the two open-loop hollow cylinders 331 correspond to the sizes of the laser output head 333 (not shown in the figure) and the input head of the optical fiber bundle 32, respectively. The open-loop hollow cylinders 331 have a certain size margin, and through the clamping fins 332 connected thereto, the two open-loop hollow cylinders 331 can clamp and fix the laser output head 333 and the optical fiber bundle 32, respectively. The clamping fins 332 are used to control the size of the open-loop hollow cylinders 331 to facilitate the fixation and removal of the laser output head 333 and the optical fiber bundle. After the laser output head 333 and the optical fiber bundle 32 are coaxially fixed by the body 336 , the laser beam 337 emitted from the laser output head 333 is focused into the optical fiber bundle 32 through the laser focusing mirror 334 in the coupling slot 335 .

[0030] The ultrasonic transducer array 21 is connected to a multi-channel signal connector 23 via a signal harness 22. The ultrasonic transducer array 21 converts the photoacoustic signal into a multi-channel electrical signal. These electrical signals are then transmitted to the multi-channel signal connector 23 via the signal harness 22. The multi-channel signal connector 23 facilitates connection to a data acquisition card or computer (not shown).

[0031] The phantom photoacoustic image collected by the endoscopic probe disclosed in the present invention is Figure 5 As shown, Figure 5 (a) and (b) are the results of photoacoustic imaging of pencil core in agar. Figure 5 (c) and (d) are the imaging results of hair in agar. Figure 5 (e) and (f) are the imaging results of stained agar in agar.

Claims

1. An endoscopic probe for photoacoustic tomography of cavity side walls, characterized in that: The invention adopts a method of arranging array transducers and array laser output on the side wall of the probe, comprising a tubular probe shell with a closed front end and a hollow interior, wherein the diameter of the tubular probe shell matches the diameter of the natural cavity to be inserted; N sound wave receiving windows and M laser output windows are opened on the side wall of the tubular probe shell, N≥1, M≥1, and no reflector is required, wherein the N sound wave receiving windows are used for the N ultrasonic transducer arrays located in the tubular probe shell to receive sound waves, and the M laser output windows are used for the M array linear laser output ports located in the tubular probe shell to output lasers; the array linear laser output ports are connected to a pluggable optical fiber connector via an optical fiber bundle; the ultrasonic transducer array is connected to a multi-channel signal connector via a signal harness; the ultrasonic transducer array and the array linear laser output ports are placed parallel to the side wall of the tubular probe shell; and the number of channels contained in a single ultrasonic transducer array is greater than 2.

2. The endoscopic probe for photoacoustic tomography of cavity side walls according to claim 1, characterized in that: The diameter of the front end of the tubular probe shell is 0.1 cm to 5 cm.

3. The endoscopic probe for photoacoustic tomography of cavity side walls according to claim 1, characterized in that: The array linear laser output port is in close contact with the ultrasonic transducer array.

4. The endoscopic probe for photoacoustic tomography of cavity sidewalls according to claim 1, wherein: The array linear laser output port outputs surface laser light in the form of a rectangular surface, a sector surface or a trapezoidal surface.

5. The endoscopic probe for photoacoustic tomography of cavity side walls according to claim 1, characterized in that: The ultrasonic transducer array is a linear array, a convex array, a concave array or a semi-circular array.

6. The endoscopic probe for photoacoustic tomography of cavity side walls according to claim 1, characterized in that: An optical fiber splitting and fixing device is provided in the tubular probe housing, which separates several thin optical fibers contained in the optical fiber bundle and arranges them into a line and then fixes them on the array linear laser output port.

7. The endoscopic probe for photoacoustic tomography of cavity side walls according to claim 1, characterized in that: The pluggable fiber optic connector includes a body, which includes two coaxial open-loop hollow cylinders of different sizes. Each open-loop hollow cylinder is connected to two clamping fins for controlling its size, and a coupling groove is provided between the two open-loop hollow cylinders. The inner ring openings of the two open-loop hollow cylinders correspond to the sizes of the laser output head and the fiber bundle input head, respectively. Through the clamping fins, the two open-loop hollow cylinders clamp and fix the laser output head and the fiber bundle, respectively.

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