Endoscope high-speed signal two-way transmission and isolation system
By employing a single-strand cable and combined electrical isolation components in the endoscope system, bidirectional transmission and isolation of high-speed signals are achieved, solving the problem that existing transmission schemes cannot meet the requirements of high-resolution images and safety isolation, thus improving the user experience and system reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-04-07
AI Technical Summary
Existing endoscopic signal transmission solutions cannot achieve high-speed bidirectional transmission and isolation, resulting in excessively large and heavy handle cables, affecting the surgical experience, and failing to meet the electrical isolation requirements of medical safety standards.
The system employs a single-strand cable for bidirectional transmission of image and control signals. Through a combination of a camera handle, transmission cable, camera host, and monitor, and utilizing components such as a CMOS image sensor, serializer parallel-to-serial conversion module, high-speed signal coupling module, electrical isolation unit, and fiber optic isolation module, it achieves bidirectional transmission and isolation of high-speed signals, meeting the electrical isolation performance requirements of medical safety standards.
It enables the simultaneous transmission of image and control signals on a single cable, reducing the size and weight of the handle cable, improving the user experience, meeting the electrical isolation requirements of medical safety standards, and improving system reliability.
Smart Images
Figure CN121814922A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of medical devices, in particular to a high-speed signal bidirectional transmission and isolation system for endoscope. BACKGROUND
[0002] Endoscopes are widely used in minimally invasive surgeries such as laparoscopy. In recent years, with the increasing demand for ultra-high-definition images in minimally invasive surgeries, the image resolution transmitted by endoscopes is getting higher and higher, and the required signal transmission rate is also getting higher and higher. The existing endoscopes generally use multiple cables to transmit signals between the camera handle and the camera main unit, mainly transmitting image signals and control signals. The number of cable strands required for signal transmission directly determines the size and weight of the handle cable. A too thick or too heavy handle cable will affect the user experience during the operation process, so it is necessary to study how to use a single cable to transmit all signals.
[0003] Endoscopes belong to medical electrical equipment. The camera handle, as a BF or CF application part, is in direct contact with the human body. The internal active device needs to be electrically isolated from the secondary circuit and the network power supply to prevent electric shock from harming the patient. Under normal circumstances, the highest isolation voltage of the application part to the network power supply required by the medical safety standard is 4000V AC. The conventional isolation chip technology currently available cannot be separated from optical coupling isolation, magnetic coupling isolation and capacitive coupling isolation, but there is no mature solution to achieve high-speed signal bidirectional transmission and isolation at a rate exceeding 200Mbps.
[0004] Based on this, the present application designs an endoscope high-speed signal bidirectional transmission and isolation system to solve the above problems. SUMMARY
[0005] In view of the above shortcomings of the prior art, the present application provides an endoscope high-speed signal bidirectional transmission and isolation system.
[0006] To achieve the above purpose, the present application realizes the following technical scheme: An endoscope high-speed signal bidirectional transmission and isolation system, comprising a camera handle, a transmission cable, a camera main unit and a display, the camera handle is used for surgery image acquisition and image signal preliminary processing, the transmission cable is used to connect one end of the camera handle and one end of the camera main unit for high-speed signal bidirectional transmission, the camera main unit is used to realize electrical isolation of the camera handle from the secondary circuit and the network power supply, as well as algorithm processing of the image signal and video interface conversion, the display is used for image display and is connected through various video interface cables and the camera main unit.
[0007] Further, the camera handle at least includes an image acquisition unit and a first image processing unit; The image acquisition unit at least includes a CMOS image sensor, and the CMOS image sensor converts an image light signal into an image electric signal through a photodiode array; The first image processing unit at least includes a Serializer module and a high-speed signal coupling module; The Serializer module is connected with the CMOS image sensor and the high-speed signal coupling module, and the high-speed signal coupling module is connected with the transmission cable.
[0008] Further, the camera host at least includes a first electrical isolation unit, a second image processing unit and a second electrical isolation unit; The first electrical isolation unit is connected with the transmission cable and the second electrical isolation unit, and the second image processing unit is connected with the second electrical isolation unit.
[0009] Further, the first electrical isolation unit at least includes a high-speed signal decoupling module, an optical fiber isolation module and a safety capacitor isolation module; The high-speed signal decoupling module is connected with the transmission cable, the optical fiber isolation module and the safety capacitor isolation module, the optical fiber isolation module and the safety capacitor isolation module are connected with the second electrical isolation unit; Further, the optical fiber isolation module at least includes an electric-to-optical component, an optical fiber component and an optical-to-electric component, the electric-to-optical component is connected with the high-speed signal decoupling module and the optical fiber component, the optical fiber component and the optical-to-electric component, and the optical-to-electric component is connected with the second image processing unit.
[0010] Further, the safety capacitor isolation module at least includes a safety capacitor, a first pin of the safety capacitor is connected with the high-speed signal decoupling module, a second pin is connected with the second electrical isolation unit, an isolation voltage of the safety capacitor is 4000V AC, and a distance between the first pin and the second pin is at least 10mm.
[0011] Further, a capacitance of the safety capacitor is not more than 4.7nF.
[0012] Further, the second image processing unit at least includes a De-Serializer module and an image processing and display main module; The De-Serializer module is connected with the image processing and display main module, the optical-to-electric component and the safety capacitor isolation module, and the image processing and display main module is connected with the first electrical isolation unit.
[0013] Further, the second electrical isolation unit at least includes a network power supply filtering module and an AC / DC isolation module, the AC / DC isolation module is connected with the image processing and display main module and the network power supply filtering module, and the network power supply filtering module is connected with a network power supply.
[0014] Compared with the prior art, the beneficial effects of this invention are as follows: This application is used to realize the simultaneous transmission of image signals and control signals on a single cable, and can achieve the electrical isolation performance required by medical safety standards. At the same time, it can be flexibly expanded according to different application scenarios. Implementing this technical solution can reduce the size and weight of the handle cable, improve the user experience, and improve system reliability. In addition, the first and second electrical isolation units realize the electrical isolation between the application part of the endoscope and the secondary circuit and the mains power supply, which meets the medical safety standards requiring the application part to have a maximum isolation withstand voltage of 4000V AC from the mains power supply. Attached Figure Description
[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.
[0016] Fig. 1 This is a block diagram of the present invention; Fig. 2 This is a block diagram of the camera handle structure of the present invention; Fig. 3 This is a block diagram of the camera host structure of the present invention. Detailed Implementation
[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0018] The terms "left," "right," "front," "back," "up," and "down" used in the following description refer to the orientation from the perspective of the front view.
[0019] Example 1: In some embodiments, please refer to the accompanying drawings. Figs. 1-3An endoscope high-speed signal bidirectional transmission and isolation system includes a camera handle 1, a transmission cable 2, a camera host 3, and a display 4. The camera handle 1 is used for surgical image acquisition and preliminary image signal processing. The transmission cable 2 is used to connect one end of the camera handle 1 and one end of the camera host 3 for high-speed bidirectional signal transmission. The camera host 3 is used to realize the electrical isolation between the camera handle 1 and the secondary circuit and the mains power supply, as well as the algorithm processing of image signals and video interface conversion. The display 4 is used for image display and is connected to the camera host 3 through various video interface cables.
[0020] The camera handle 1 includes at least an image acquisition unit 10 and a first image processing unit 20; The image acquisition unit 10 includes at least one CMOS image sensor 11, which converts the image light signal into the image electrical signal through a photodiode array; The number of CMOS image sensors 11 can be adjusted according to the application scenario, for example, two CMOS image sensors 11 can be included to realize 3D function; The first image processing unit 20 includes at least a serializer parallel-to-serial module 21 and a high-speed signal coupling module 22; The serializer parallel-to-serial module 21 is connected to the CMOS image sensor 11 and the high-speed signal coupling module 22, and the high-speed signal coupling module 22 is connected to the transmission cable 2.
[0021] The Serializer parallel-to-serial module 21 receives MIPI parallel image signals and converts them into serial image signals. The Serializer parallel-to-serial module 21 also converts the I2C signals configured by the CMOS image sensor into bidirectional control signals. The Serializer parallel-to-serial module is also connected to the Serializer. The serializer module 21 sends the status information of the camera handle 1 to the camera host 3 and receives control commands from the camera host 3; The serializer module 21 uses a main chip that is either an FPGA programmable logic chip or an ASIC application-specific integrated circuit chip.
[0022] The high-speed signal coupling module 22 couples the bidirectional control signal to the serial image signal through the LC coupling circuit and transmits it to the transmission cable 2, thereby realizing high-speed bidirectional signal transmission.
[0023] The transmission cable 2 includes at least a single-strand cable, a shielding braided layer, and a protective outer sheath. The single-strand cable is connected to the high-speed signal coupling module 22. The shielding braided layer is located outside the single-strand cable, and the protective outer sheath is located outside the shielding braided layer.
[0024] The single-strand cable includes at least one single-core coaxial cable for high-speed bidirectional transmission of single-ended signals.
[0025] The camera host 3 includes at least a first electrical isolation unit 30, a second image processing unit 40, and a second electrical isolation unit 50; The first electrical isolation unit 30 is connected to the transmission cable 2 and the second electrical isolation unit 40, and the second image processing unit 40 is connected to the second electrical isolation unit 50.
[0026] The first electrical isolation unit 30 includes at least a high-speed signal decoupling module 31, an optical fiber isolation module 32, and a safety capacitor isolation module 33. The high-speed signal decoupling module 31 is connected to the transmission cable 2, the optical fiber isolation module 32 and the safety capacitor isolation module 33, and the optical fiber isolation module 32 and the safety capacitor isolation module 33 are connected to the second electrical isolation unit 40. The high-speed signal decoupling module 31 works in conjunction with the transmission cable 2 to achieve high-speed bidirectional signal transmission over a single cable. The high-speed signal decoupling module 31 decouples the bidirectional control signal from the serial image signal. The decoupled serial image signal and the decoupled bidirectional control signal are restored to two independent physical channels. The decoupled serial image signal enters the fiber optic isolation module 32, and the decoupled bidirectional control signal is restored to the safety capacitor isolation module 33. The fiber optic isolation module 32 includes at least an electro-optical component 321, an optical fiber component 322, and an optical-electrical component 323. The electro-optical component 321 is connected to the high-speed signal decoupling module 31 and the optical fiber component 322. The optical fiber component 322 and the optical-electrical component 323 are connected to the second image processing unit 40.
[0027] The electro-optical component 321 converts the serial image electrical signal decoupled from the high-speed signal decoupling module 31 into an optical signal. The optical fiber component 322 serves as the physical carrier for optical signal transmission and simultaneously achieves electrical isolation. The optical fiber component 322 transmits the optical signal to the optical-to-electric component 323, which then converts the optical signal back into a serial image electrical signal for transmission to the second image processing unit 40. The optical fiber isolation module 32 has at least one physical channel, and multiple optical fiber physical channels can meet the needs of higher bandwidth image transmission.
[0028] The safety capacitor isolation module 33 includes at least one safety capacitor. The first pin of the safety capacitor is connected to the high-speed signal decoupling module 31 to receive the bidirectional control signal after decoupling from the high-speed signal decoupling module 31. The second pin is connected to the second electrical isolation unit 40. The isolation withstand voltage of the safety capacitor is 4000V AC, and the distance between the first pin and the second pin is at least 10mm. The capacitance of the safety capacitor does not exceed 4.7nF, thereby achieving electrical isolation between the front and rear stages of the bidirectional control signal. The safety capacitor is connected to a terminating resistor, and the safety capacitor and the terminating resistor form an RC high-pass filter circuit. When the bidirectional control signal contains consecutive "1"s or "0"s, a DC voltage drop (LF Droop) is generated, which in turn causes pattern jitter (PDJ). To limit the maximum DC voltage drop, a suitable -3dB cutoff frequency needs to be set. , and and The calculation formula is:
[0029]
[0030] in: This is the capacitance value. For terminating resistors, The fundamental frequency clock period of the signal. The length of consecutive levels. The rise time of the signal is 20% - 80%.
[0031] The larger the capacitance of the safety capacitor, the more DC component can pass through the bidirectional control signal, resulting in a lower DC voltage drop and a smaller PDJ. Simultaneously, it must meet the leakage current limits specified in medical safety standards. The capacitance of the safety capacitor shall not exceed 4.7nF. The calculation formula is: in V is the test voltage frequency, and V is the test voltage.
[0032] The second image processing unit 40 includes at least a De-Serializer module 41 and an image processing and display main module 42; The De-Serializer serial-to-parallel module 41 is connected to the image processing and display main module 42, the photoelectric conversion component 323, and the safety capacitor isolation module 33. The image processing and display main module 42 is connected to the second electrical isolation unit 50. The De-Serializer serial-to-parallel module 41 converts the serial image signal re-converted by the photoelectric converter 323 into a parallel MIPI image signal and transmits it to the image processing and display main module 42. At the same time, the De-Serializer serial-to-parallel module 41 converts the bidirectional serial signal into an I2C control signal. The main chip of the De-Serializer serial-to-parallel conversion module 41 is either an FPGA programmable logic chip or an ASIC dedicated integrated circuit chip. The image processing and display main module 42 sends control commands such as configuration parameters and exposure parameters of the CMOS image sensor 11 through I2C control signals, receives MIPI image signals for processing, and converts them into various video interfaces for external display of images. Video interfaces include, but are not limited to, SDI, DP, HDMI, and DVI.
[0033] The second electrical isolation unit 50 includes at least a mains power filter module 51 and an AC / DC isolation module 52. The AC / DC isolation module 52 is connected to the image processing and display main module 42 and the mains power filter module 52. The mains power filter module 52 is connected to the mains power supply. The mains power filtering module 52 performs EMI filtering on the mains power supply, suppresses the electromagnetic noise of the mains power supply, generates AC mains power, and at the same time prevents electromagnetic interference generated by the switching power supply itself from polluting the power grid. The AC / DC isolation module 52 converts the AC mains power supply into the DC power supply required by the image processing and display main module 42. The AC / DC isolation module 52 realizes electrical isolation between the mains power supply and the secondary circuit. The isolation withstand voltage performance needs to meet 4000V AC and has a 2xMOPP safety level.
[0034] This application enables the simultaneous transmission of image and control signals on a single cable while achieving the electrical isolation performance required by medical safety standards. Furthermore, it allows for flexible expansion based on different application scenarios. Implementation of this technical solution reduces the size and weight of the handle cable, improves the user experience, and enhances system reliability. In addition, the first electrical isolation unit 30 and the second electrical isolation unit 50 achieve electrical isolation between the endoscope's application section and the secondary circuitry and mains power supply, meeting the medical safety standards requirement that the application section's maximum isolation withstand voltage to the mains power supply is 4000V AC.
[0035] The specific steps are as follows: The camera handle 1 acquires parallel image signals through the image acquisition unit 10, which are then converted into serial image signals coupled with bidirectional control signals by the first image processing unit 20. These signals are then connected to the camera host 3 via a transmission cable 2 composed of a single-strand coaxial cable to achieve high-speed bidirectional transmission of endoscope signals. The camera host 3 decouples the bidirectional control signals from the serial image signals through the first electrical isolation unit 30. The serial image signals and bidirectional control signals are electrically isolated using an optical fiber isolation module 32 and a safety capacitor isolation module 33. The isolated serial image signals and bidirectional control signals are then connected to the second image processing unit 40 for signal serial-to-parallel conversion and image processing, and finally converted into various video interfaces to connect to the display 4 for image display.
[0036] Most 4K resolution CMOS image sensors use MIPI CSI-2 technology for 4K image transmission, requiring at least one clock channel and four data channels. A single channel bandwidth can reach 1.5Gbps, but this only supports transmission distances of a few tens of centimeters, which cannot meet the 3-6 meter transmission cable requirements. Therefore, SERDES technology must be used to enhance the signal transmission distance. For a single 4K raw10@60frame / s CMOS image sensor, considering only effective pixels, the required video stream bandwidth is 4.98Gbps per second. However, considering the maximum 20% blanking area (Blank pixels) and the 8b / 10b encoding overhead of SERDES high-speed signal transmission, the actual required video stream bandwidth is at most 7.4Gbps.
[0037] Due to the physical insertion loss of the cable and considering interference resistance, the bandwidth of the video stream that a single cable can transmit is limited. Currently, it can only support the video stream bandwidth required by a single 4K raw10@60frame / s CMOS image sensor. If the actual application scenario requires two or more CMOS image sensors for image acquisition, such as two CMOS image sensors for 3D functionality, the resolution of a single CMOS image sensor can be reduced to 2K, or the frame rate of a single CMOS image sensor can be reduced to 30frame / s, or the transmission cable can be increased to two strands.
[0038] The serial image signal is a unidirectional transmission signal, sent from the camera handle 1 to the camera host 3 in the forward direction. The camera host 3 does not need to send the image back to the camera handle 1 in the reverse direction. The operating rate is 7.4Gbps, with high-frequency energy concentrated in the 3.7GHz-18.5GHz range. After 8b / 10b encoding, the intermediate frequency energy is concentrated in the 740MHz region. The bidirectional control signal is a bidirectional transmission signal, with the camera handle sending status information to the camera host in the forward direction, and the camera host sending control commands back to the camera handle in the reverse direction. The operating rate is 200Mbps, with high-frequency energy concentrated in the 100MHz-500MHz range. After 8b / 10b encoding, the intermediate frequency energy is concentrated in the 20MHz region.
[0039] The serial image signal output by the high-speed signal decoupling module 31 is connected to the optical-to-electrical side of the fiber optic isolation module 321, which converts the serial image signal into an optical signal for transmission. The optical signal is transmitted through the optical fiber 322 to the optical-to-electrical side of the fiber optic isolation module, where it is converted back into a serial image signal for transmission to the next stage. Electrical isolation of the serial image signal is achieved through the optical fiber 322.
[0040] The bidirectional control signal output by the high-speed signal decoupling module 31 is connected to pin 1 of the safety capacitor isolation module. After transmission through the safety capacitor, it is transmitted to the next stage from pin 2. The electrical isolation of the bidirectional control signal is achieved through the safety capacitor. The isolation withstand voltage performance of the safety capacitor needs to meet 4000V AC.
[0041] Specifically, the bidirectional control signal uses 8b / 10b encoding, the maximum continuous same level length (NCID) is 5, the bidirectional control signal rate is 200Mbps, the base frequency at NRZ level is 100MHz, and the corresponding clock cycle is... The terminating resistor is 10 ns. It is 50Ω. = 7.8nF, = 100ps, = 400kHz.
[0042] However, in order to meet the leakage current limits specified in medical safety standards... Safety capacitors typically have a capacitance value not exceeding 4.7nF, therefore the actual circuit parameters are: = 4.7nF, = 160ps, = 677kHz.
[0043] The above 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 the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A high-speed bidirectional signal transmission and isolation system for endoscopes, characterized in that: The system includes a camera handle (1), a transmission cable (2), a camera host (3), and a display (4). The camera handle (1) is used for surgical image acquisition and preliminary image signal processing. The transmission cable (2) is used to connect one end of the camera handle (1) and one end of the camera host (3) for high-speed bidirectional signal transmission. The camera host (3) is used to realize the electrical isolation between the camera handle (1) and the secondary circuit and the mains power supply, as well as the algorithm processing of image signals and video interface conversion. The display (4) is used for image display and is connected to the camera host (3) through various video interface cables.
2. The high-speed bidirectional transmission and isolation system for endoscope signals according to claim 1, characterized in that, The camera handle (1) includes at least an image acquisition unit (10) and a first image processing unit (20); The image acquisition unit (10) includes at least one CMOS image sensor (11), which converts the image light signal into the image electrical signal through a photodiode array; The first image processing unit (20) includes at least a serializer parallel-to-serial module (21) and a high-speed signal coupling module (22); The serializer parallel-to-serial module (21) is connected to the CMOS image sensor (11) and the high-speed signal coupling module (22), and the high-speed signal coupling module (22) is connected to the transmission cable (2).
3. The high-speed bidirectional transmission and isolation system for endoscope signals according to claim 2, characterized in that, The camera host (3) includes at least a first electrical isolation unit (30), a second image processing unit (40) and a second electrical isolation unit (50); The first electrical isolation unit (30) is connected to the transmission cable (2) and the second electrical isolation unit (40), and the second image processing unit (40) is connected to the second electrical isolation unit (50).
4. The high-speed bidirectional transmission and isolation system for endoscope signals according to claim 3, characterized in that, The first electrical isolation unit (30) includes at least a high-speed signal decoupling module (31), an optical fiber isolation module (32), and a safety capacitor isolation module (33). The high-speed signal decoupling module (31) is connected to the transmission cable (2), the optical fiber isolation module (32) and the safety capacitor isolation module (33), and the optical fiber isolation module (32) and the safety capacitor isolation module (33) are connected to the second electrical isolation unit (40).
5. The high-speed bidirectional transmission and isolation system for endoscope signals according to claim 4, characterized in that, The fiber optic isolation module (32) includes at least an electro-optical component (321), an optical fiber component (322), and an optical-electrical component (323). The electro-optical component (321) is connected to the high-speed signal decoupling module (31) and the optical fiber component (322). The optical fiber component (322) and the optical-electrical component (323) are connected to the second image processing unit (40).
6. The high-speed bidirectional transmission and isolation system for endoscope signals according to claim 5, characterized in that, The safety capacitor isolation module (33) includes at least one safety capacitor. The first pin of the safety capacitor is connected to the high-speed signal decoupling module (31), and the second pin is connected to the second electrical isolation unit (40). The isolation withstand voltage of the safety capacitor is 4000V AC, and the distance between the first pin and the second pin is at least 10mm.
7. The high-speed bidirectional transmission and isolation system for endoscope signals according to claim 6, characterized in that, The capacitance of the safety capacitor shall not exceed 4.7nF.
8. The high-speed bidirectional transmission and isolation system for endoscope signals according to claim 6, characterized in that, The second image processing unit (40) includes at least a De-Serializer serial-to-parallel module (41) and an image processing and display main module (42). The De-Serializer serial-to-parallel module (41) is connected to the image processing and display main module (42), the photoelectric conversion component (323), and the safety capacitor isolation module (33). The image processing and display main module (42) is connected to the second electrical isolation unit (50).
9. The high-speed bidirectional transmission and isolation system for endoscope signals according to claim 7 or 8, characterized in that, The second electrical isolation unit (50) includes at least a mains power filter module (51) and an AC / DC isolation module (52). The AC / DC isolation module (52) is connected to the image processing and display main module (42) and the mains power filter module (52). The mains power filter module (52) is connected to the mains power supply.