A near-infrared two-region fluorescence imaging capsule endoscope and a capsule endoscope system

Abstract

The application discloses a near-infrared two-region fluorescence imaging capsule endoscope and a capsule endoscope system. The capsule endoscope comprises a capsule shell, a light source module, an image acquisition module and a wireless energy receiving module arranged in the shell. The light source module comprises at least two near-infrared LEDs and two white light LEDs. The image acquisition module is used for acquiring white light images and NIR-II fluorescence images. The wireless energy receiving module comprises a rectifier and voltage stabilizing circuit board and a three-dimensional receiving coil connected to the rectifier and voltage stabilizing circuit board, so as to receive external wireless transmitted energy and supply power to each module in the capsule. The system comprises a NIR-II fluorescence probe, an external wireless energy supply system and an image receiving and processing system matched with the capsule endoscope. Through the dual-mode imaging design and the external wireless energy supply technology, the application realizes high sensitivity, high resolution, strong penetration ability, high signal-to-noise ratio imaging detection of early cancerous tissue in the gastrointestinal tract in a single noninvasive examination.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and more particularly to a near-infrared two-zone fluorescence imaging capsule endoscope and capsule endoscope system. Background Technology

[0002] Gastrointestinal cancer is a serious malignant tumor that poses a significant threat to human health worldwide. Early-stage cancer lesions are small and less prone to metastasis, making early and accurate diagnosis crucial for improving patient survival rates. However, current detection technologies still have significant limitations in terms of non-invasiveness, imaging depth, and resolution, necessitating the development of novel imaging methods with high sensitivity, high resolution, strong penetration, and a high signal-to-noise ratio.

[0003] Currently, while tethered endoscopy is considered the "gold standard" in clinical practice, its invasive nature often causes patient discomfort and requires a high level of skill from physicians. In contrast, capsule endoscopy, with its non-invasive nature and lack of sedation requirement, has become an important auxiliary diagnostic tool. Existing commercial capsule endoscopes are mostly based on white light imaging technology, which, while usable for examining the small intestine and colon, has limited penetration depth, making it difficult to clearly visualize the submucosal layer and deep tissue structures; furthermore, its resolution limitations can easily lead to missed detections of early, minute lesions.

[0004] To overcome the limitations of white light imaging, several improved capsule imaging technologies have emerged in recent years, such as ultrasound imaging capsules, optical coherence tomography (OCT) capsules, narrowband imaging capsules, and fluorescence imaging capsules. While these technologies have improved imaging performance to some extent, they still fail to fully meet the clinical needs for early lesion detection: ultrasound capsules face challenges in integrating miniature transducers; OCT capsules face challenges in continuous power supply and scanning stability; narrowband imaging, while improving mucosal surface contrast, suffers from insufficient penetration depth due to strong short-wavelength scattering; and existing fluorescence capsules, whether relying on autofluorescence or near-infrared I (NIR-I) fluorescence, suffer from low signal-to-noise ratio, limited penetration, or low imaging contrast.

[0005] Near-infrared II (NIR-II, 900–1700 nm) fluorescence imaging, as an emerging technology, offers lower tissue scattering and absorption, stronger penetration, and a higher signal-to-noise ratio compared to NIR-I, theoretically making it highly suitable for detecting early deep lesions in the gastrointestinal tract. However, most current NIR-II imaging devices are bulky, making encapsulation integration difficult, and miniaturization of energy and detection modules remains a challenge.

[0006] Therefore, existing gastrointestinal cancer detection methods each have limitations, failing to simultaneously achieve high sensitivity, high resolution, deep penetration, and high signal-to-noise ratio imaging under non-invasive conditions. There is an urgent need to propose a capsule endoscope and capsule endoscope system based on NIR-II fluorescence imaging to achieve high-performance non-invasive diagnosis of early-stage cancerous tissues. Summary of the Invention

[0007] The purpose of this invention is to provide a near-infrared two-zone fluorescence imaging capsule endoscope and capsule endoscope system to solve the above-mentioned technical problems existing in the prior art.

[0008] To achieve the above objectives, in one aspect, the present invention provides a near-infrared II fluorescence imaging capsule endoscope, comprising: a capsule shell; a light source module disposed within the capsule shell, including at least two near-infrared LEDs with a center wavelength greater than 800 nm and at least two white LEDs; an image acquisition module disposed within the capsule shell for acquiring white light images and NIR-II fluorescence images; and a wireless power receiving module including a rectifier and voltage regulator circuit board and a three-dimensional receiving coil connected thereto, for receiving energy transmitted wirelessly from the outside and powering the various modules within the capsule.

[0009] Optionally, the center wavelength of the near-infrared LED is 808±5nm, which is used to excite the NIR-II fluorescent probe to generate a fluorescence signal with a wavelength exceeding 1000nm.

[0010] Optionally, the image acquisition module includes: a CMOS image sensor soldered onto a circular circuit board; a lens threaded onto a lens base; a band-blocking filter disposed at the top of the lens to filter out 808nm excitation light and allow white light and NIR-II fluorescence signals to pass through; and an opaque heat-shrink tubing wrapped around the bonding joint between the lens and the band-blocking filter to prevent excitation light and reflected light from seeping into the lens cavity through the bonding gap between the band-blocking filter and the lens.

[0011] Furthermore, the band-blocking filter has a thickness of 2 mm and a diameter of 4.7 mm.

[0012] Optionally, the light source module is integrated on a ring-shaped circuit board with an outer diameter of 10.2 mm and an inner diameter of 6.3 mm, and is arranged around the front of the image acquisition module.

[0013] Optionally, the lens base is provided with a base slot, which is 1.75mm higher than the imaging surface of the sensor chip. The annular circuit board is embedded in the base slot, effectively blocking the path of the excitation light to the CMOS image sensor through the gap of the lens base.

[0014] Optionally, the three-dimensional receiving coil consists of three mutually orthogonal one-dimensional coils, which are connected in series with three sets of tuning capacitors to form a resonant circuit.

[0015] Optionally, the one-dimensional coil is wound with a single strand of copper wire with a diameter of 0.12 mm and has a high permeability magnetic core inside.

[0016] On the other hand, the present invention also provides a dual-modal imaging capsule endoscope system, comprising an NIR-II capsule endoscope, an NIR-II fluorescent probe, an external wireless power supply system, and an image receiving and processing system, wherein the NIR-II capsule endoscope is a near-infrared two-zone fluorescence imaging capsule endoscope as described in any of the above claims, and the NIR-II fluorescent probe emits NIR-II fluorescence signals with wavelengths exceeding 1000 nm under the excitation of the near-infrared LED.

[0017] Optionally, the NIR-II fluorescent probe comprises a hydrophobic NIR-II fluorescent dye molecule and a targeting micelle structure coated thereon.

[0018] Optionally, the external wireless power supply system includes: a transmitting coil for inducing an alternating magnetic field; a DC voltage source for powering an inverter circuit board; an inverter circuit board for converting DC voltage into AC voltage; a fixed and adjustable capacitor connected in series with the transmitting coil; and a movable examination bed for carrying the examinee and positioning the abdomen within the space enclosed by the transmitting coil.

[0019] Optionally, the transmitting coil is a Helmholtz coil structure consisting of 80 turns of Litz wire made of 250 strands of enameled wire.

[0020] Furthermore, the image receiving and processing system includes: an image receiver for receiving image data transmitted by the capsule endoscope; and an image processing module for processing white light images and NIR-II fluorescence images.

[0021] Furthermore, the image processing module includes a white light imaging recognition module and an NIR-II fluorescence imaging recognition module.

[0022] Furthermore, the image receiving and processing system also includes a computer and a memory for further analysis, processing, and storage of the images.

[0023] Furthermore, the image receiver is a mobile terminal with a dedicated application installed.

[0024] Furthermore, the application is configured to switch between white light imaging mode and NIR-II fluorescence imaging mode in real time.

[0025] Furthermore, the external wireless power supply system provides continuous power to the capsule endoscope via electromagnetic induction.

[0026] Furthermore, the dual-modal imaging capsule endoscope system also includes a microcontroller module and a wireless signal transmission module. The microcontroller module is used to control the operation of each module of the system and to compress the acquired image data in real time. The wireless signal transmission module is used to wirelessly transmit the compressed image data to an external image receiving and processing system.

[0027] Furthermore, the wireless signal transmission module employs Bluetooth Low Energy technology.

[0028] Compared with the prior art, the present invention discloses at least the following beneficial effects:

[0029] This invention, by meticulously integrating a light source module containing near-infrared LEDs and white LEDs of specific wavelengths within the capsule cavity, and combining it with a band-stop filter possessing precise spectral characteristics, enables the capsule endoscope to simultaneously achieve high-quality white light imaging and NIR-II fluorescence imaging in a single swallowing examination. This not only clearly presents the macroscopic morphological structure of the gastrointestinal mucosa but also provides high-contrast, high-signal-to-noise ratio functional imaging of deep lesions enriched with NIR-II fluorescent probes. Specifically, the use of a three-dimensionally orthogonally arranged receiving coil and a matching rectifier and voltage regulator circuit constitutes a highly efficient wireless power receiving mechanism, ensuring a continuous and stable power supply to the capsule within the body, thus effectively overcoming the inherent limitation of limited battery life in traditional systems. Simultaneously, the optimized light source arrangement and filter structure effectively suppress cross-interference between different wavelength light signals, significantly improving the consistency and reliability of imaging. Ultimately, this technical solution achieves breakthroughs in multiple dimensions, including sensitivity, resolution, and penetration depth, for the non-invasive diagnosis of early gastrointestinal cancers, providing clinicians with a novel solution for early, accurate, and comprehensive detection. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is an exploded view of the NIR-II capsule endoscope in an embodiment of the present invention;

[0032] Figure 2 This is a layout diagram of the ring circuit board of the light source module in an embodiment of the present invention:

[0033] Figure 3 This is a schematic diagram of the structure of the miniature camera module in an embodiment of the present invention;

[0034] Figure 4 This is a circuit and coil structure diagram of the wireless power receiving module in an embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of the structure of the NIR-II fluorescent probe in an embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram of the hardware configuration of the external wireless power supply system in an embodiment of the present invention;

[0037] Figure 7 This is a structural framework diagram of the image receiving and processing module in an embodiment of the present invention;

[0038] Figure 8 This is a flowchart of a system detection method for early gastrointestinal cancer diagnosis according to an embodiment of the present invention.

[0039] Figure 9 This is a schematic diagram illustrating the measurement results of the emission spectra of near-infrared LEDs, white LEDs, and NIR-II fluorescent probes using a spectrometer in an embodiment of the present invention.

[0040] Figure 10 This is a schematic diagram of the cell viability staining experiment results in an embodiment of the present invention;

[0041] Figure 11 This is a schematic diagram of the experimental results of nanoprobe cytotoxicity (CCK-8 assay) in an embodiment of the present invention;

[0042] Figure 12 This is a schematic diagram of the results of a tumor-targeting imaging experiment in nude mice in an embodiment of the present invention.

[0043] In the diagram: 1. NIR-II capsule endoscope; 2. NIR-II fluorescent probe; 3. External wireless power supply system; 4. Image receiving and processing system; 101. Light source module; 102. Image acquisition module; 103. Microcontroller module; 104. Wireless signal transmission module; 105. Power supply module; 106. Rectifier and voltage regulator circuit board; 107. Three-dimensional receiving coil; 108. Capsule bottom cover; 109. Capsule optically transparent dome; 110. Capsule body; 1011. First near-infrared light bead; 1012. First white light bead; 1013. Second near-infrared light bead; 1014. Second white light bead; 1015. Third white light bead; 1016. Circular circuit board; 1021. CMOS image sensor; 1022. Lens base; 1023. Lens; 1024. Band-blocking filter; 1025. Circular... Circuit board; 1026, base slot; 1027, opaque heat shrink tubing; 1061, first tuning capacitor; 1062, second tuning capacitor; 1063, third tuning capacitor; 1064, first rectifier; 1065, second rectifier; 1066, third rectifier; 1067, voltage regulator chip; 1071, first-dimensional receiving coil; 1072, second-dimensional receiving coil; 1073, third-dimensional receiving coil; 201, NIR-II fluorescent dye small molecule; 202, folic acid polyethylene glycol phospholipid; 301, transmitting coil; 302, DC voltage source; 303, inverter circuit board; 304, fixed and adjustable capacitor; 305, movable inspection bed; 401, image receiver; 402, white light imaging recognition module; 403, NIR-II fluorescence imaging recognition module; 404, computer; 405, memory. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] Capsule endoscopy, due to its non-invasive and sedation-free nature, has become an important supplementary method for gastrointestinal examinations. Commercially available capsule endoscopes are primarily based on white light imaging technology; however, white light imaging has weak tissue penetration, making it difficult to clearly observe the submucosal layer and deeper tissue structures. To overcome the shortcomings of white light imaging, researchers have explored various novel imaging technologies for capsule endoscopes in an attempt to improve penetration depth and image quality; however, these technologies still do not fully meet the needs of clinical applications.

[0046] 1. Ultrasonic Imaging Capsule Endoscopy: Multiple research teams are dedicated to integrating high-frequency micro-ultrasound technology into capsules in an attempt to obtain more penetrating transmural images. However, this technology is still in its early stages of development, facing numerous challenges in the development and integration of key components such as miniature ultrasonic transducers.

[0047] 2. Optical Coherence Tomography (OCT) Capsule Endoscopy: Thanks to the micron-level high resolution of OCT technology, it shows potential in the detection of gastrointestinal mucosal damage and early cancer. However, to realize true capsule applications, issues such as continuous power supply and scanning stability during intestinal peristalsis still need to be addressed.

[0048] 3. Narrow-band imaging capsule endoscopy: This technology utilizes the differences in absorption and reflection of light of different wavelengths by tissues to enhance the imaging contrast of the mucosal surface. However, its short-wavelength light is strongly scattered, resulting in shallow penetration depth and difficulty in clearly observing deep structures; furthermore, the significant autofluorescence of tissues in this band can easily introduce additional background noise, reducing the image signal-to-noise ratio.

[0049] 4. Fluorescence Imaging Capsule Endoscopy: Combining the non-invasive characteristics of capsule endoscopy with the high sensitivity of fluorescence imaging, it provides a new approach for early lesion detection. It mainly includes two categories: autofluorescence imaging and near-infrared one-zone (NIR-I) fluorescence imaging.

[0050] Near-infrared II (NIR-II) fluorescence imaging technology, as an emerging field, has shown significant advantages in biomedical research. However, current NIR-II imaging devices are mostly large, desktop-type devices. Miniaturizing and integrating them into capsule systems still faces several technical obstacles, including but not limited to excessive device size, difficulties in continuous power supply, and the challenges of integrating miniaturized detectors and light sources. Therefore, developing a capsule endoscopy system based on NIR-II fluorescence imaging to achieve high-performance, non-invasive detection of early-stage cancerous tissues in the gastrointestinal tract has become a key technical problem urgently needing to be solved in this field.

[0051] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] Example 1

[0053] Reference Figure 1As shown, Embodiment 1 of the present invention provides a near-infrared II fluorescence imaging capsule endoscope, the overall structure of which is encapsulated by a biocompatible capsule shell, making it compact and suitable for operation in the narrow environment of the gastrointestinal tract. The capsule shell includes a capsule body 110, an optically transparent capsule dome 109, and a capsule bottom cover 108. The capsule shell includes a light source module 101, an image acquisition module 102, a microcontroller module 103, a wireless signal transmission module 104, a power supply module 105, and a wireless energy receiving module, wherein the wireless energy receiving module includes a rectifier and voltage regulator circuit board 106 and a three-dimensional receiving coil 107. The modules work together through electrical connections and mechanical fixation to achieve dual-modal detection functions of white light imaging and NIR-II fluorescence imaging.

[0054] In this embodiment, the light source module 101 is integrated on a ring circuit board 1016. The ring circuit board 1016 has an outer diameter of 10.2 mm and an inner diameter of 6.3 mm. It is cleverly arranged around the front of the image acquisition module 102, which saves space and ensures uniform illumination.

[0055] The light source module 101 includes two types of LEDs: near-infrared LEDs and white LEDs. Two near-infrared LEDs are included: a first near-infrared LED bead 1011 and a second near-infrared LED bead 1013. Both are custom-designed small-sized devices, measuring 2.0mm × 1.6mm, with a center wavelength greater than 800nm, preferably 808±5nm. These two near-infrared LEDs are dedicated to exciting the NIR-II fluorescent probe 2, causing it to emit NIR-II fluorescence signals with wavelengths exceeding 1000nm. The selected 808nm LED has high light intensity output and narrow peak characteristics, which can efficiently excite the target probe while avoiding spectral interference with the white LEDs. Three white LEDs are included: a first white LED bead 1012, a second white LED bead 1014, and a third white LED bead 1015, measuring 1.6mm × 0.8mm, used to provide traditional white light illumination. The five LED beads are rationally arranged on the ring circuit board 1016 to ensure uniform illumination of the capsule's inner surface and improve imaging consistency.

[0056] Through the scientific arrangement and independent control of the five LED beads, this system achieves the core function of "single ingestion, dual-mode imaging." That is, in a single inspection, the white LED is first activated for large-scale morphological observation. If a suspicious area is found, the system can immediately switch to the 808nm near-infrared LED excitation mode to initiate NIR-II fluorescence imaging, thus forming a progressive detection strategy from macroscopic localization to microscopic diagnosis.

[0057] Further optimization of the design resulted in the near-infrared LED being packaged in a 2.0mm × 1.6mm surface mount package, and the white LED being a broadband white LED packaged in a 1.6mm × 0.8mm surface mount package. While meeting optical performance requirements, the design also considered miniaturization and spatial layout flexibility, with components evenly distributed and soldered onto a rigid circular PCB (i.e., circular circuit board 1016) with an inner diameter of 6.3mm and an outer diameter of 10.2mm.

[0058] Further optimization of the scheme allows both near-infrared LEDs and white LEDs to achieve a light emission angle of 120°, enabling wide-area uniform illumination and ensuring sufficient coverage of the gastrointestinal tract wall without blind spots, thereby improving the accuracy and completeness of diagnosis.

[0059] Excitation light with wavelengths greater than 800 nm has low absorption and scattering characteristics in biological tissues and strong penetration ability, which can effectively improve imaging depth and spatial resolution, providing more accurate and in-depth imaging support for the early diagnosis of gastrointestinal cancer. White LED provides uniform surface illumination, which can clearly display the mucosal surface morphology. Combined with the advantages of NIR-II fluorescence imaging in deep tissue detection, the system realizes complementary fusion of dual-modal imaging, which can more comprehensively assess the location, morphology and invasion range of tumors.

[0060] In this embodiment, the image acquisition module 102 is located at the front end of the capsule and is mainly responsible for capturing white light images and NIR-II fluorescence images. Its core components include a CMOS image sensor 1021, a band-blocking filter 1024, a lens 1023, and a lens base 1022.

[0061] In one specific embodiment, the CMOS image sensor 1021 uses the GC0308 chip from Galaxycore Microelectronics, which measures 3.2mm × 2.7mm and supports VGA resolution of 640 × 480. This sensor possesses excellent photosensitivity and low noise characteristics. It is configured via a microcontroller using the IIC (Integrated Circuit Bus) protocol and connected to the main control chip through a digital video port (DVP) to achieve high-speed image acquisition and data transmission.

[0062] In one specific embodiment, a band-blocking filter 1024 is mounted in front of the lens 1023. It has a thickness of 2 mm and a diameter of 4.7 mm. Its main function is to filter out the 808 nm excitation light while allowing white light and NIR-II fluorescence signals to pass through. It is also used to further suppress the excitation light and reflected light from entering the CMOS image sensor 1021 through the lens 1023.

[0063] In one specific embodiment, the lens 1023 is screwed onto the lens base 1022, which is then tightly fixed to the surface of the circular circuit board 1025 with opaque black UV adhesive and strictly aligned with the optical axis of the CMOS image sensor 1021 to ensure image clarity and focal length stability, and to adapt to the reliable operation of the capsule in the dynamic gastrointestinal environment.

[0064] To further optimize the design, the lens base 1022 is configured as a stepped slot structure, including a base slot 1026. After the lens base 1022 is fixed, the annular circuit board 1016 is embedded in the base slot 1026, which is 1.75mm higher than the imaging surface of the sensor chip, effectively blocking the path of the excitation light to the CMOS image sensor 1021 through the gap of the lens base 1022.

[0065] To further optimize the solution, an opaque heat shrink tubing 1027 is used to wrap around the bonding joint between the lens 1023 and the band-blocking filter 1024, further preventing excitation light and reflected light from seeping into the lens cavity through the bonding gap between the band-blocking filter 1024 and the lens 1023.

[0066] Through the design of the base slot 1026 on the lens base 1022, the light source module 101 and the image acquisition module 102 equipped with the CMOS image sensor 1021 are designed separately. The use of a light-blocking filter 1024, along with the opaque heat-shrink tubing 1027 encasing the lens 1023 and the collaborative operation of the light-blocking filter 1024, effectively suppresses background interference caused by the excitation light source, ensuring a high signal-to-noise ratio and image quality for NIR-II fluorescence imaging. Simultaneously, the separate design of the light source module 101 and the image acquisition module 102 equipped with the CMOS image sensor 1021 physically isolates the path of the excitation light penetrating from the lens base 1022 to the CMOS image sensor 1021.

[0067] In this embodiment, the microcontroller module 103 serves as the control center of the system, employing a high-performance STM32H743AII6 chip to uniformly schedule the operation of each module. It establishes communication with the wireless signal transmission module 104 via the SPI bus and performs real-time compression processing on the acquired raw image data to improve transmission efficiency.

[0068] In this embodiment, the wireless signal transmission module 104 adopts Bluetooth Low Energy technology, with an integrated chip of nRF52840-CKAA, packaged in WLCSP, and featuring a dual-core architecture. Its transmit power can be adjusted in 4dB steps between -20dBm and +8dBm, maintaining a stable communication link during penetration of human tissue and meeting the data backhaul requirements between the capsule and external receiving devices.

[0069] In this embodiment, the power module 105 uses two switching voltage source chips (MPM3804), each in a QFN-10 package (2mm×2mm). After being adjusted by a resistor network, one output is 2.8V, dedicated to powering the CMOS image sensor 1021 and the white LED; the other output is 2.2V, which powers the microcontroller, the wireless communication chip, and the 808nm near-infrared LED.

[0070] In this embodiment, the wireless energy receiving module consists of a rectifier and voltage regulator circuit board 106 and a three-dimensional receiving coil 107, which is used to receive energy transmitted by the external wireless power supply system 3 and extend the working time of the capsule.

[0071] In one specific embodiment, the rectifier and voltage regulator circuit board 106 is soldered with three tuning capacitors, three BAS4002 rectifiers, and one voltage regulator chip 1067. The three independent tuning capacitors (first tuning capacitor 1061, second tuning capacitor 1062, and third tuning capacitor 1063) are connected in series with their respective coils to form a resonant circuit, matching optimal energy transfer conditions. The three rectifiers include a first rectifier 1064, a second rectifier 1065, and a third rectifier 1066; the voltage regulator chip 1067 uses an LT8609 chip. The first rectifier 1064, the second rectifier 1065, and the third rectifier 1066, together with the voltage regulator chip 1067, complete the AC-to-DC conversion and stabilize the voltage output.

[0072] In one specific embodiment, such as Figure 4 As shown, the three-dimensional receiving coil 107 is composed of a first-dimensional receiving coil 1071, a second-dimensional receiving coil 1072, and a third-dimensional receiving coil 1073, which are arranged in pairs orthogonal to each other. Each coil is wound with a single strand of copper wire with a diameter of 0.12 mm and has a high-permeability manganese-zinc ferrite core embedded inside to enhance the mutual inductance coefficient with the external transmitting coil 301, thereby significantly improving the energy receiving efficiency.

[0073] Example 2

[0074] Reference Figures 1 to 7 As shown, Embodiment 2 of the present invention provides a dual-modal imaging capsule endoscope system, including an NIR-II capsule endoscope 1, an NIR-II fluorescence probe 2, an external wireless power supply system 3, and an image receiving and processing system 4. The NIR-II capsule endoscope 1 is the near-infrared two-zone fluorescence imaging capsule endoscope described in Embodiment 1, possessing dual-mode functionality of white light imaging and NIR-II fluorescence imaging.

[0075] like Figure 5As shown, the NIR-II fluorescent probe 2 consists of a hydrophobic NIR-II fluorescent dye molecule 201 as the core, and is coated with a micelle structure composed of folic acid polyethylene glycol phospholipid 202. This structure endows the probe with good water solubility and blood circulation stability, and can actively accumulate in tumor or lesion areas (such as malignant cells that overexpress the corresponding receptor) with the help of folic acid or other targeting ligands.

[0076] In one specific embodiment, when the probe is excited by an 808nm LED, its fluorescence emission wavelength is above 1000nm, which has the following superior characteristics: lower photon scattering and absorption rate in tissue, greater tissue penetration depth, higher spatial resolution and signal-to-noise ratio, and less autofluorescence background interference, ultimately achieving higher contrast functional imaging.

[0077] like Figure 6 As shown, the external wireless power supply system 3 provides continuous external energy input to the capsule, and includes a transmitting coil 301, a DC voltage source 302, an inverter circuit board 303, a fixed and adjustable capacitor 304, and a movable examination bed 305, for providing continuous external energy input to the capsule endoscope.

[0078] In one specific embodiment, the DC voltage source 302 includes a UDP8305M and a UDP8303M. The UDP8305M generates two square wave signals with opposite phases, a 50% duty cycle, a frequency of 100kHz, and a voltage amplitude of 15V. The inverter circuit board 303 implements a full-bridge inverter circuit, consisting of four N-channel enhancement-mode MOSFETs (metal-oxide-semiconductor field-effect transistors), with each pair forming a half-bridge circuit. Each half-bridge circuit is controlled by a UDP8303M and is used to convert the DC voltage generated by the DC voltage source 302 into AC voltage. Specifically, the enhancement-mode MOSFETs can be IRFR4615. A fixed and adjustable capacitor 304 is connected in series with the transmitting coil 301. When the capacitive reactance of the capacitor and the inductive reactance of the coil are equal, the coil current reaches its maximum, providing optimal output energy for the capsule endoscope. As the voltage value of the UDP8303M in the DC voltage source 302 increases, the output power also increases. The transmitting coil 301 is a Helmholtz coil structure with 80 turns of Litz wire wound from 250 strands of enameled wire. Considering power consumption and size requirements during examination, the coil frame diameter is designed to be 52cm, and the width of a single coil is 10cm. The movable examination bed 305 allows the examinee to lie down with their abdomen placed in the transmitting coil 301, facilitating flexible adjustment of the patient's position during examination and effectively coordinating with the wireless power transmission space. The entire external wireless power supply system 3 works in conjunction with the wireless power receiving module inside the capsule to establish a stable and reliable power channel, completely breaking through the time limitations of traditional battery power.

[0079] like Figure 7As shown, the image receiving and processing system 4 includes an image receiver 401, a white light imaging recognition module 402, an NIR-II fluorescence imaging recognition module 403, a computer 404, and a memory 405, used for real-time display, processing, and storage of images acquired by the capsule endoscope. The white light imaging recognition module 402, the NIR-II fluorescence imaging recognition module 403, and the computer 404 constitute an image processing module for subsequent image processing; the memory 405 is used to store the acquired and processed images for subsequent examination and diagnosis.

[0080] In one specific embodiment, the image receiving and processing system 4 includes an Android application for real-time display and control of the capsule endoscope's imaging capabilities. Any Android device with the application installed can function as the image receiver 401.

[0081] To further optimize the solution, this embodiment of the system also supports real-time switching of imaging modes via a mobile terminal APP, and intelligent analysis and archiving of images, providing a comprehensive, non-invasive and efficient solution for the diagnosis of early gastrointestinal cancers.

[0082] like Figure 8 As shown, the operating procedure for diagnosing early gastrointestinal cancers using this system is as follows:

[0083] First, the NIR-II fluorescent probe 2 is injected intravenously. Approximately 24 hours later, the subject orally ingests the capsule endoscope and is placed supine on the movable examination table 305, with their abdomen centered within the space enclosed by the transmitting coil 301 to ensure optimal wireless power coupling efficiency. The capsule moves through the gastrointestinal tract with natural peristalsis, sequentially performing the following steps:

[0084] White light imaging mode: Turn on all three white light LEDs to simultaneously acquire images of the macroscopic structure of the digestive tract for preliminary localization and screening of abnormal areas.

[0085] NIR-II fluorescence imaging mode: The white LED is turned off, and two 808nm near-infrared LEDs are lit to excite the NIR-II fluorescent probe 2, which has been enriched in the lesion area, causing it to emit a high-intensity NIR-II fluorescence signal. At this time, the lesion tissue with the probe attached will appear as a significant bright area in the imaging image, forming a clear distinction from the surrounding normal tissue, greatly improving the specificity and accuracy of diagnosis.

[0086] Throughout the examination process, the captured images are transmitted in real time to the external image receiving and processing system 4 via wireless communication, and displayed instantly by a mobile terminal APP. Medical staff can then perform real-time interpretation based on these images, and can further upload the images to computer 404 for subsequent analysis and archiving (storage 405) for later follow-up comparison.

[0087] The effectiveness of the above diagnostic procedures was verified, and the verification results are as follows: Figures 9 to 12 As shown.

[0088] I. Emission Spectroscopy Testing of Capsule Endoscope Light Source, Filters, and Nanomaterials: The emission spectra of near-infrared LEDs, white LEDs, and NIR-II fluorescent nanoprobes were measured using a spectrometer. The transmittance of the filters was determined using a UV-Vis infrared spectrophotometer (Carry5000). Test results are as follows: Figure 9 As shown.

[0089] II. Live / Dead Cell Staining and Fluorescence Observation: This example investigated the effects of 808–810 nm wavelength light sources and white LED light on cell viability. The human gastric mucosal epithelial cell line GES-1 was used for the experiment: First, GES-1 cells in logarithmic growth phase and in good growth condition were divided into groups of 1 × 10⁶ cells per well. 5 Cells were seeded into confocal culture dishes and pre-cultured for 24 hours. Then, the cells were randomly divided into three groups: the first group was a blank control and was not exposed to light; the second group was exposed to white LED light; and the third group was exposed to a near-infrared light source with a wavelength of 808–810 nm. Both groups were continuously exposed to light for 30 minutes.

[0090] After irradiation treatment, live / dead cell double staining working solution was added to each group of cells, and incubation continued for 30 minutes. Cells were then washed with PBS and incubated at room temperature for 30–45 minutes before removing the staining solution to terminate the reaction. Finally, the staining of each group of cells was observed using confocal microscopy, and image data were obtained through six independent replicate experiments. The live / dead cell ratio was analyzed and calculated using ImageJ software. The results showed that the live / dead cell ratio was higher than 95% in all six experiments, indicating that neither of the two light sources of this NIR-II fluorescence imaging capsule endoscope prototype caused significant cytotoxicity and possesses good biocompatibility. Figure 10 As shown.

[0091] III. To evaluate the biocompatibility of the upconversion fluorescent nanoprobe CH1055@DSPE-PEG-FA, this example used the CCK-8 assay to detect its effect on GES-1 cell viability. The specific steps are as follows: GES-1 cells were cultured at 4 × 10⁶ cells per well. 3 Cells were seeded at a density of [number] cells per well in 96-well plates and cultured overnight to allow adhesion. The medium was then replaced with fresh medium containing different concentrations of CH1055@DSPE-PEG-FA, and cultured for another 24 hours. Next, the cells were gently washed three times with PBS, and fresh medium was added again. CCK-8 assays were performed according to standard procedures to determine the relative viability of the cells. [Details omitted] Figure 11 As shown.

[0092] IV. HCT116 cells cultured under standard conditions and in the logarithmic growth phase were digested, centrifuged, resuspended, and then the cell concentration was adjusted to 5 × 10⁻⁶. 8 Cells / mL. An 8-week-old nude mouse weighing approximately 25g was subcutaneously inoculated with 100µL of the above cell suspension in its right buttock, and fed continuously until the tumor volume reached 200–500 mmHg. 3 After tumor formation, 200 μL of nanoprobe solution was injected via the tail vein at a dose equivalent to 7 mg / kg of mouse body weight.

[0093] Subsequently, at different time points (0h, 2h, 12h, 24h, 48h, 72h, 96h, 132h, 180h, 240h), fluorescence signals in mice were collected using the NIR-II capsule endoscope 1 in conjunction with a mobile terminal, and corresponding pseudo-color thermograms were generated. This system can accurately identify the distribution changes in the tumor region after the injection of nanoprobes, achieving dynamic monitoring.

[0094] like Figure 12 As shown, the experimental results demonstrate that the constructed NIR-II capsule endoscope imaging platform can effectively achieve targeted imaging of tumor regions in tumor-bearing mouse models. The high-contrast fluorescence pseudo-color images of NIR-II displayed on the mobile device further verify the system's efficient detection capability for deep tumors and early micro-lesions.

[0095] In summary, the NIR-II fluorescence imaging capsule endoscope system provided in this embodiment, by integrating two core technologies—external wireless power supply and targeted NIR-II fluorescence imaging—successfully overcomes the inherent bottlenecks of traditional capsule endoscopes in terms of power supply duration, penetration depth, and imaging accuracy, opening up a new technical approach for the early, non-invasive, and precise diagnosis and treatment of gastrointestinal cancers.

[0096] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to 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 this invention.

[0097] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A near-infrared dual-zone fluorescence imaging capsule endoscope, characterized in that, include: Capsule shell; The light source module (101) is disposed inside the capsule shell and includes at least two near-infrared LEDs with a center wavelength greater than 800nm ​​and at least two white LEDs; the light source module (101) is integrated on a ring circuit board (1016), which is arranged around the front of the image acquisition module (102); An image acquisition module (102), disposed within the capsule shell, is used to acquire white light images and NIR-II fluorescence images. The image acquisition module (102) includes a CMOS image sensor (1021), a lens base (1022), a lens (1023), a band-stop filter (1024) disposed at the top of the lens (1023), and an opaque heat-shrink tubing (1027) wrapped around the adhesive joint between the lens (1023) and the band-stop filter (1024). The band-stop filter (1024) is used to filter out 808nm excitation light and allow... White light and NIR-II fluorescence signals are transmitted. The opaque heat shrink tubing (1027) is used to prevent excitation light and reflected light from seeping into the lens cavity through the adhesive gap between the band-blocking filter (1024) and the lens (1023). The lens base (1022) is provided with a base slot (1026). The base slot (1026) is higher than the imaging surface of the sensor chip. The annular circuit board (1016) is embedded in the base slot (1026) to effectively block the path of excitation light to the CMOS image sensor (1021) along the gap of the lens base (1022). The wireless power receiving module includes a rectifier and voltage regulator circuit board (106) and a three-dimensional receiving coil (107) connected thereto, for receiving energy transmitted wirelessly from the outside and powering the modules inside the capsule.

2. The near-infrared dual-zone fluorescence imaging capsule endoscope according to claim 1, characterized in that, The center wavelength of the near-infrared LED is 808±5nm, which is used to excite the NIR-II fluorescent probe (2) to generate a fluorescent signal with a wavelength of more than 1000nm.

3. The near-infrared dual-zone fluorescence imaging capsule endoscope according to claim 1, characterized in that, The annular circuit board (1016) has an outer diameter of 10.2 mm and an inner diameter of 6.3 mm.

4. The near-infrared dual-zone fluorescence imaging capsule endoscope according to claim 3, characterized in that, The base slot (1026) is 1.75 mm higher than the imaging surface of the sensor chip.

5. The near-infrared dual-zone fluorescence imaging capsule endoscope according to claim 1, characterized in that, The three-dimensional receiving coil (107) consists of three mutually orthogonal one-dimensional coils, which are connected in series with three sets of tuning capacitors to form a resonant circuit.

6. The near-infrared dual-zone fluorescence imaging capsule endoscope according to claim 5, characterized in that, The one-dimensional coil is wound with a single strand of copper wire with a diameter of 0.12 mm and has a high permeability magnetic core inside.

7. A capsule endoscope system with dual-modal imaging, characterized in that, The device includes a NIR-II capsule endoscope (1), an NIR-II fluorescent probe (2), an external wireless power supply system (3), and an image receiving and processing system (4). The NIR-II capsule endoscope (1) is a near-infrared two-zone fluorescence imaging capsule endoscope as described in any one of claims 1 to 6. The NIR-II fluorescent probe (2) emits NIR-II fluorescent signals with wavelengths exceeding 1000 nm under the excitation of the near-infrared LED.

8. The capsule endoscope system with dual-modal imaging according to claim 7, characterized in that, The NIR-II fluorescent probe (2) comprises a hydrophobic NIR-II fluorescent dye molecule (201) and a targeting micelle structure encapsulated thereon.

9. The capsule endoscope system with dual-modal imaging according to claim 7, characterized in that, The external wireless power supply system (3) includes: The transmitting coil (301) is used to induce an alternating magnetic field; A DC voltage source (302) is used to power the inverter circuit board (303); Inverter circuit board (303) is used to convert DC voltage to AC voltage; A fixed and adjustable capacitor (304) is connected in series with the transmitting coil (301); A movable examination bed (305) is used to carry the examinee and place the abdomen within the space enclosed by the transmitting coil (301).

10. The capsule endoscope system with dual-modal imaging according to claim 9, characterized in that, The transmitting coil (301) is a Helmholtz coil structure consisting of 250 strands of enameled wire wound with 80 turns of Litz wire.

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