An endoscopic imaging system for photodynamic diagnosis

Abstract

The present application relates to the technical field of endoscopic imaging, in particular to an endoscopic imaging system for photodynamic diagnosis, comprising an excitation light generating assembly, a fluorescence generating assembly and a processing assembly; the light path of a white light source is orthogonal to the light path of a blue light source, a dichroic mirror is arranged at the orthogonal position, the dichroic mirror is 45 degrees to the optical axis of the light path of the white light source and also 45 degrees to the optical axis of the light path of the blue light source; the dichroic mirror can transmit photons of the white light band and reflect photons of the blue light band, so that the emitted light of the blue light source is reflected by the dichroic mirror and has the same emission direction as the white light source; the fused light beams of the white light source and the blue light source pass through the third collimating lens and enter the endoscopic module through a light guide beam. The present application can simultaneously acquire color images and fluorescence images, doctors can make more comprehensive and accurate diagnosis, do not need to frequently convert the working mode, save the operation time, improve the use convenience of the equipment and reduce the missed detection rate.

Description

Technical Field

[0001] This invention relates to the field of endoscopic imaging technology, and more specifically to an endoscopic imaging system for photodynamic diagnosis. Background Technology

[0002] In the field of endoscopic imaging technology, optical imaging has many advantages such as being non-destructive and low-cost, making it highly valuable. Traditional white light endoscopy uses white light illumination to obtain detailed surface structures of lesions, allowing doctors to identify tumor areas through surface abnormalities. However, the contrast between early-stage tumors and normal mucosa is low, easily leading to missed diagnoses. Fluorescence endoscopy, a novel diagnostic device using fluorescence spectroscopy, detects tumors by detecting the accumulation of fluorescent reagents on tissue surfaces. Due to its high sensitivity, it can identify tumor areas that are difficult to detect under white light endoscopy, making it an important supplementary tool to white light endoscopy.

[0003] Currently, the most common fluorescence endoscopes are those using ICG (indigo green) fluorescence endoscopes. Because their fluorescence band is located in the near-infrared region I, which does not overlap with the white light band, they can be simultaneously illuminated by white light and excitation light and collected by beam splitting at the camera end, thus achieving simultaneous imaging of white light and fluorescence.

[0004] However, the fluorescent agents used in photodynamic diagnosis, such as 5-ALA (5-aminolevulinic acid), have a fluorescence wavelength in the 620-640nm range, which overlaps with white light, making it impossible to simultaneously acquire white light and fluorescence images using the methods described above. Current methods using fluorescence mode illumination only provide blue light in the 380-420nm wavelength range, which is filtered out at the camera end. Therefore, the final image only shows red fluorescent areas, making it almost impossible to discern surface tissue structures. During surgery, doctors must frequently switch illumination modes to obtain both fluorescence and white light images to confirm the diagnostic results.

[0005] Therefore, there is an urgent need to design an endoscopic imaging system for photodynamic diagnosis that can simultaneously acquire white light and fluorescence, and then fuse the acquired images into a cleaned lesion tissue image through post-processing. Summary of the Invention

[0006] To address the aforementioned issues, this invention provides an endoscopic imaging system for photodynamic diagnosis, which integrates white light illumination and fluorescence illumination modes to reduce the false negative rate while improving ease of use and accuracy of examination results.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] An endoscopic imaging system for photodynamic diagnosis includes an excitation light generating component, a fluorescence generating component, and a processing component;

[0009] The excitation light generating component includes a white light source, a first collimating lens, and a filter arranged in sequence, wherein the filter is a band-stop filter;

[0010] The fluorescence generating component includes a blue light source and a second collimating lens arranged sequentially.

[0011] The processing components include an endoscope module, an adapter lens, a camera module, and an image processing module connected in sequence;

[0012] The optical path of the white light source is orthogonal to the optical path of the blue light source. A dichroic mirror is placed at the orthogonal position. The dichroic mirror is at a 45-degree angle to both the optical axis of the white light source and the optical axis of the blue light source. The dichroic mirror can transmit photons in the white light band and reflect photons in the blue light band, so that the emitted light from the blue light source, after being reflected by the dichroic mirror, has the same emission direction as the white light source.

[0013] Along the emission direction of the white light source, a third collimating lens is provided behind the dichroic mirror. The fused beam of the white light source and the blue light source enters the endoscope module through the third collimating lens and then through the beam guide.

[0014] Furthermore, the white light source is one of a laser, an LED light source, or an externally introduced light source.

[0015] Furthermore, the blue light source is one of a laser, an LED light source, or an externally introduced light source.

[0016] Furthermore, the stopband of the filter is 620-640nm.

[0017] Furthermore, the filter is rotated under the control of a stepper motor.

[0018] Furthermore, the processing component also includes a display for displaying the image.

[0019] Furthermore, the turning wavelength of the dichroic mirror is 420 nm.

[0020] Furthermore, the camera module includes a beam splitter, a monochrome image sensor, and a color image sensor; the beam splitter forms a 45-degree angle with the imaging light entering the camera module, a portion of the imaging light is reflected by the beam splitter and then illuminates the monochrome image sensor, and another portion of the imaging light is transmitted through the beam splitter and then illuminates the color image sensor.

[0021] Furthermore, the beam splitter is coated with a 620-640nm light-transmitting film on the lower surface of the black-and-white image sensor, allowing light with wavelengths in the 620-640nm range to pass through.

[0022] Furthermore, the beam guide includes multiple image transmission fiber monofilaments and an optical fiber sheath wrapped around the bundled image transmission fiber monofilaments.

[0023] The beneficial effects of this invention are as follows:

[0024] 1. This invention uses a band-stop filter to block a small amount of spectral information from a white light source. A dichroic mirror is used to fuse the white and blue light, which have lost some spectral information, onto the tissue. The imaging light reflected from the tissue is converted by the camera module. A color image sensor acquires the white light image (with the lost spectral information) for observing surface structure information, while a black-and-white image sensor acquires fluorescence information. Through spatial alignment of the imaging module in the early stages, the two images can be fused. This enables the simultaneous acquisition of white light and fluorescence images in photodynamic diagnosis using photosensitizers such as 5-ALA. Doctors can make more comprehensive and accurate diagnoses based on the information from both sources, eliminating the need for frequent switching of operating modes, saving surgical time, improving the ease of use of the equipment, and reducing the false negative rate.

[0025] 2. In this invention, the filter is driven by a stepper motor. The stepper motor pulls the filter out of the optical path, and the image processing unit only collects the image from the color image sensor. The system can then obtain a white light image without losing any spectral information, making the device more widely applicable. Attached Figure Description

[0026] Figure 1 This is a connection diagram of the present invention.

[0027] Figure 2 This is a schematic diagram of the camera module described in this invention.

[0028] Explanation of reference numerals in the attached figures:

[0029] 1-White light source, 2-Blue light source, 3-First collimating lens, 4-Second collimating lens, 5-Filter, 6-Dichroic mirror, 7-Third collimating lens, 8-Beam guide, 9-Endoscopic module, 10-Adapter lens, 11-Camera module, 12-Image processing module, 13-Display, 14-Beam splitter, 15-Black and white image sensor, 16-Color image sensor. Detailed Implementation

[0030] The technical solution of the present invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention. It should be noted that the terms "center," "upper," "lower," "vertical," "horizontal," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0031] like Figure 1-2 As shown, the present invention provides an endoscopic imaging system for photodynamic diagnosis, including an excitation light generating component, a fluorescence generating component, and a processing component;

[0032] The excitation light generating component includes a white light source 1, a first collimating lens 3, and a filter 5 arranged in sequence. The filter 5 is a band-stop filter. The wavelength range of the light emitted by the white light source 1 is 420-680nm.

[0033] The fluorescence generating component includes a blue light source 2 and a second collimating lens 4 arranged sequentially; the wavelength range of the light emitted by the blue light source 2 is 380-420nm.

[0034] The processing components include an endoscope module 9, an adapter lens 10, a camera module 11, and an image processing module 12 connected in sequence;

[0035] The optical path of the white light source 1 is orthogonal to the optical path of the blue light source 2. A dichroic mirror 6 is placed at the orthogonal position. The dichroic mirror 6 is at a 45-degree angle to both the optical axis of the white light source 1 and the optical axis of the blue light source 2. The dichroic mirror 6 can transmit photons in the white light band and reflect photons in the blue light band, so that the emitted light from the blue light source 2, after being reflected by the dichroic mirror 6, has the same emission direction as the white light source 1.

[0036] Along the emission direction of the white light source 1, a third collimating lens 7 is provided on the rear side of the dichroic mirror 6. The fused beam of the white light source 1 and the blue light source 2 enters the endoscope module 9 through the third collimating lens 7 and the beam guide 8.

[0037] Specifically, the white light source 1 is an LED light source, but it can also be a laser or an externally introduced light source.

[0038] Specifically, the blue light source 2 is an LED light source, or it can be a laser or an externally introduced light source.

[0039] Specifically, the stopband of the filter 5 is 620-640nm. When photons from the white light source 1 pass through the filter 5, the filter 5 blocks photons with wavelengths in the range of 620-640nm from passing through.

[0040] Furthermore, the filter 5 is rotated under the control of a stepper motor.

[0041] Furthermore, the processing component also includes a display 13 for displaying the image.

[0042] Specifically, the turning wavelength of the dichroic mirror 6 is 420 nm.

[0043] Specifically, the camera module 11 includes a beam splitter 14, a monochrome image sensor 15, and a color image sensor 16. The beam splitter 14 forms a 45-degree angle with the imaging light entering the camera module 11. A portion of the imaging light is reflected by the beam splitter 14 and then illuminates the monochrome image sensor 15, while another portion of the imaging light is transmitted through the beam splitter 14 and then illuminates the color image sensor 16.

[0044] Furthermore, the lower surface of the beam splitter 14 near the black-and-white image sensor 15 is coated with a 620-640nm light-transmitting film.

[0045] Specifically, the beam guide 8 is a traditional medical optical fiber beam guide or a medical liquid beam guide, comprising multiple image transmission fiber monofilaments and an optical fiber jacket tube wrapped around the bundled image transmission fiber monofilaments.

[0046] This invention has two working modes: white light mode and fluorescence mode. In white light mode, the stepper motor controls the filter 5 to rotate, and the filter 5 is pulled out of the white light path. At the same time, the blue light source 2 does not work, and the image processing module 12 only collects the image of the color image sensor 16. The system can obtain a white light image without losing any spectral information.

[0047] In fluorescence mode, white light emitted from white light source 1 is collimated into parallel light by the first collimating lens 3, and then filtered by the filter 5 to remove spectral information within the wavelength range of 620-640nm. The filtered white light then passes through the dichroic mirror 6. Simultaneously, blue light emitted from blue light source 2 is collimated into parallel light by the second collimating lens 4, and then the blue light is reflected by the dichroic mirror 6 and merged with the white light. The merged beam passes through the third collimating lens 7 and the beam guide into the endoscope module 9, and is then irradiated onto the tissue via the optical fiber of the endoscope module 9. The wavelength of the white light remains unchanged after reflection from the tissue, while the fluorescence wavelength of the blue light excited by the photosensitizer in the tissue is 620-640nm. The white light reflected from the tissue and the excited fluorescence are projected into the camera module 11 through the lens group and the adapter lens 10 within the endoscope module 9 for photoelectric conversion.

[0048] White light and excited fluorescence are projected onto the beam splitter 14 of the imaging module 11. The spectral information passing parallel to the beam splitter 14 illuminates the color image sensor 16. After reflection by the beam splitter 14, only the spectral information in the 620-640nm range illuminates the monochrome image sensor 15. Therefore, the color image sensor 16 acquires the white light image, and the monochrome image sensor 15 acquires the fluorescence image. The image processing module 12 collects the image information from the color image sensor 16 and the monochrome image sensor 15 and performs fusion processing. Doctors can then make a more comprehensive and accurate diagnosis based on the fused image information, reducing the false negative rate.

[0049] Experiments have shown that, although the white light image acquired in fluorescence mode loses spectral information in the 620-640nm range, its impact on the diagnostic results is negligible. Furthermore, this invention can acquire both white light and fluorescence images simultaneously, improving diagnostic efficiency. Under the same tissue conditions, this invention can save 60% of the diagnostic time.

[0050] The above specific embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An endoscopic imaging system for photodynamic diagnosis, characterized in that, It includes an excitation light generation component, a fluorescence generation component, and a processing component; The excitation light generating assembly includes a white light source, a first collimating lens, and a filter arranged sequentially. The filter is a band-stop filter with a stopband of 620-640nm. The filter is driven to rotate by a stepper motor. In normal white light mode, the filter is rotated out of the excitation light generating assembly; in fluorescence mode, the filter is rotated back into the excitation light generating assembly. The fluorescence generating component includes a blue light source and a second collimating lens arranged sequentially. The processing components include an endoscope module, an adapter lens, a camera module, and an image processing module connected in sequence; The camera module includes a beam splitter, a monochrome image sensor, and a color image sensor. The beam splitter forms a 45-degree angle with the imaging light entering the camera module. A portion of the imaging light is reflected by the beam splitter and then illuminates the monochrome image sensor, while another portion of the imaging light is transmitted through the beam splitter and then illuminates the color image sensor. The beam splitter is coated with a 620-640nm light-transmitting film on the lower surface of the black and white image sensor. The optical path of the white light source is orthogonal to the optical path of the blue light source. A dichroic mirror is placed at the intersection of the orthogonal optical paths of the white light source and the blue light source. The dichroic mirror is at a 45-degree angle to both the optical axis of the white light source and the optical axis of the blue light source. The white light source emits photons in the white light band with a wavelength of 420-680nm. The dichroic mirror can transmit the photons in the 420-680nm white light band and reflect the photons in the blue light band, so that the emitted light from the blue light source, after being reflected by the dichroic mirror, has the same emission direction as the white light source. Along the emission direction of the white light source, a third collimating lens is provided behind the dichroic mirror. The fused beam of the white light source and the blue light source enters the endoscope module through the third collimating lens and then through the beam guide.

2. The endoscopic imaging system according to claim 1, characterized in that: The white light source is one of the following: laser, LED light source, or externally introduced light.

3. The endoscopic imaging system according to claim 1, characterized in that: The blue light source is one of the following: laser, LED light source, or externally introduced light.

4. The endoscopic imaging system according to claim 1, characterized in that: The processing component also includes a display for displaying the image.

5. The endoscopic imaging system according to claim 1, characterized in that: The dichroic mirror has a turning wavelength of 420 nm.

6. The endoscopic imaging system according to claim 1, characterized in that: The beam guide includes multiple image transmission fiber monofilaments and an optical fiber sheath wrapped around the bundled image transmission fiber monofilaments.

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