Medical imaging devices with electrical noise reduction

Abstract

We provide an intrusive medical device configured to mitigate electrical noise. [Solution] An invasive medical device 40 and a visualization system 20 including the invasive medical device, wherein the invasive medical device includes a proximal end and a distal end spaced apart from the proximal end, a camera 60 and a light source located at the distal end, and a cable bundle 70 consisting of a first coaxial cable and a second coaxial cable in a common shield 74, the cable bundle extending from the proximal end to the distal end and electrically connected to the camera and light source at the distal end, and the common shield electrically connecting the ground to the camera and light source.

Description

Technical Field

[0001] The present disclosure relates to invasive medical devices equipped with a distal camera, such as endoscopes and breathing tubes, and more particularly to invasive medical devices configured to mitigate electrical noise.

Background Art

[0002] Visualization systems including a video processing device electrically connected to an invasive medical device are known. The visualization system can be used for visual navigation into hollow organs and body cavities, as well as for the examination and diagnosis of hollow organs and body cavities, and optionally for assisting in surgeries such as for target tissue sampling. Exemplary invasive medical devices include endoscopes and breathing tubes. Endoscopes include endoscopes specialized for procedures such as bronchoscopes, arthroscopes, cystoscopes, ureteroscopes, choledochoscopes, colonoscopes, laparoscopes, gastroscopes, and duodenoscopes. Breathing tubes include endotracheal tubes, tracheal tubes, tracheostomy tubes, and other tubes configured to ventilate at least a portion of a patient's respiratory system or lungs, and may include a pharyngeal mask or an inflatable cuff. A visualization system including an endoscope operable with a surgical tool is described in U.S. Patent No. 10,646,107 to common owners. Breathing tubes are described in U.S. Patent No. 9,486,595 to common owners, U.S. Patent No. 9,889,264 to common owners, U.S. Patent No. 10,406,309 to common owners, and U.S. Patent No. 10,888,679 to common owners. A visualization system including a portable medical monitor having a display screen is described in U.S. Patent No. 11,266,297 to common owners and U.S. Patent No. 11,328,390 to common owners.

[0003] Electrosurgical instruments can be guided through the lumen of an invasive medical device to perform medical procedures within a patient's body cavity. Known electrosurgical tools operated by high-voltage pulses (e.g., in the range of 2kV to 8kV) can generate high-frequency noise in signals and interference in images that are apparent to the user during the procedure. An example of such an electrosurgical tool is one configured to perform argon plasma coagulation (APC). Argon plasma coagulation is an electrosurgical unipolar procedure for surface hemostasis, deactivation, and ablation using ionized argon gas, which can be readily ionized as an inert gas. The high-voltage pulse results in a strong electric field (high frequency) that can be experienced as high-frequency noise on a conductor. Electrical noise in the image signal can also be caused by a high-frequency clock signal (which can be, for example, 4, 12, or 24 MHz, depending on the specific image sensor). This electrical noise is sometimes called "hum" or "cross-clock."

[0004] Electrical noise can lead to image degradation or loss of live images for various reasons, including camera module "freezing" (requiring a reset), and failure of communication of control data configuration to the camera, i.e., data being written to the wrong location or incorrect data being written in the camera's registers.

[0005] Furthermore, known invasive medical devices may include diameters larger than 3.4 mm and may have sufficient space to avoid imposing size or configuration limitations on the conductor. However, as the size of invasive medical devices decreases, it is desirable to reduce the size and configuration of the conductor, especially when their distal ends have a diameter of 3.4 mm or less, which is desirable for mitigating tissue damage and facilitating navigation within the patient.

[0006] Furthermore, it is desirable to present images on the display screen in real time. Known medical monitors may employ image processing algorithms configured to mitigate the effects of electrical noise. For example, a medical monitor may average frames (e.g., frames or sequences of images) in the video stream, or exclude frames from the video stream if they are defective, for example, if the frame shows vertical or horizontal lines, large areas of overexposure or underexposure, or otherwise defective. This is not ideal, as it may show the doctor outdated frames, even if only for a fraction of a second. If the image processing algorithm is modified to present the video stream in real time or near real time, these video stream noise reduction techniques are eliminated, and electrical noise in invasive medical devices must be reduced or eliminated to ensure a proper user experience.

[0007] Furthermore, image processing algorithms can be modified to add features such as navigation and tissue / object recognition, which, if added without removing code, may require larger and more expensive hardware. Therefore, the elimination of noise reduction processing instructions can be made possible by improvements to invasive medical devices, resulting in overall cost savings.

[0008] Single-use invasive medical devices optimize workflows and reduce costs while saving patient lives and improving patient care. They optimize workflows and reduce costs because they are always ready when needed, without the large capital and repair budgets traditionally required for reusable invasive medical devices. For example, sterilization and storage facilities are avoided, there is no need to maintain proof of sterilization, and invasive medical devices do not need to be transported from sterilization and storage facilities to the building where they are needed, sometimes at night or on weekends. They save patient lives and improve patient care because they are readily available and do not pose a risk of cross-contamination. This also reduces readmissions. Although single-use invasive medical devices are discarded after a single patient use (one or more procedures may be performed while the patient remains in the treatment room), the environmental impact of reusable invasive medical devices, due to cleaning materials, CO2 emissions during the cleaning process, and the use of disposable personal protective equipment by personnel involved in the transportation and sterilization of reusable invasive medical devices, can be similar to that of single-use invasive medical devices. To further reduce environmental impact, the invasive medical devices described herein are primarily made from polymer materials.

[0009] For the reasons mentioned above, it is desirable to incorporate noise mitigation features into invasive medical devices, particularly single-use medical devices, to enhance their value and, in particular, their effectiveness when electronic noise-generating tools are used.

[0010] To further expand the advantages of single-use invasive medical devices, it is desirable to broaden the applicability of invasive medical devices, for example, by enabling smaller devices.

[0011] To further expand the advantages of single-use invasive medical devices, it is desirable to reduce manufacturing costs. [Overview of the project]

[0012] The purpose of this disclosure is to provide an invasive medical device that eliminates or at least reduces the drawbacks of prior art invasive medical devices and has features that adequately address the problems described above. In particular, the purpose of this disclosure is to present an invasive medical device that exhibits reduced electrical noise interference compared to prior art invasive medical devices.

[0013] The first aspect relates to extending the applicability of the invasive medical device outlined in claim 1 and the visualization system described in claim 12. Advantageous embodiments are claimed in dependent claims and / or described below. An advantage of the invasive medical device described in claim 1 is that electrical noise is effectively mitigated. Furthermore, the use of coaxial cables facilitates a compact structure, as detailed below.

[0014] In the variant of the embodiment described in claim 1, the coaxial cables are not twisted together. Twisted-pair coaxial cables, in which two coaxial cables are twisted together, may have the potential advantage of increased electrical noise reduction. However, arranging the coaxial cables side by side without twisting them together allows for a cable bundle with a very low profile, which is advantageous because it can allow for an overall reduction in the diameter of the insertion cord or its distal end by having a narrow radial profile when assembled.

[0015] In another variation of this embodiment, the shield of the first cable is configured to electrically connect to and power a light source, the central conductor of the first cable is configured to electrically connect to a camera and transmit video signals, the shield of the second cable is configured to electrically connect to the camera and supply power, and the central conductor of the second cable is configured to electrically connect to the camera and transmit clock signals. In other words, the shield of the first cable powers the light source, the central conductor of the first cable transmits video signals from the camera, the shield of the second cable powers the camera, and the central conductor of the second cable transmits clock signals to the camera. This configuration separates the light source power conductor from the clock signal conductor, which may be beneficial in mitigating potential electrical noise from the light source power conductor to the clock signal. The shield of the first cable, the central conductor of the first cable, the shield of the second cable, and the central conductor of the second cable may be connected directly or indirectly to the light source and the camera. The light source power conductor may be independent of the camera power conductor.

[0016] In another variant of this embodiment, the shield of the first cable is configured to electrically connect and power the light source, the central conductor of the first cable is configured to electrically connect the camera and transmit the clock signal, the shield of the second cable is configured to electrically connect and power the camera, and the central conductor of the second cable is configured to electrically connect the camera and transmit the video signal. This configuration separates the light source power conductor from the video signal conductor, which may be beneficial in mitigating potential electrical noise from the light source power conductor to the video signal.

[0017] In one example of this embodiment, the coaxial cable is 0.0005 mm 2 ~0.0055mm 2 Within the interval, for example, 0.0008 mm 2 ~0.0035mm 2 Within the interval, for example, 0.0014 mm 2This is a microcoaxial cable with a central conductor cross-sectional area of ​​0.0055 mm². These cross-sectional areas of the central conductor have been found to be suitable for invasive medical devices. 2 Larger cross-sectional areas offer advantages such as conductor robustness and relatively low electrical resistance, but are now undesirable due to the increased size of cable bundles. 0.0005mm 2 While a lower cross-sectional area has the advantage of facilitating very compact structures, increased electrical resistance, physical fragility, and generally higher costs make it a less desirable option.

[0018] In one example of this embodiment, the cable bundles have heights ranging from 0.2 mm to 0.6 mm, for example, 0.35 mm, within a spacing of 0.1 to 0.7 mm. Cable bundle heights below 0.7 mm are advantageously found for invasive medical devices because this allows for a very compact structure with the minimum external dimensions of the invasive medical device, and / or the invasive medical device to have a large working channel. Thus, a low cable bundle height is relevant to both small invasive medical devices, such as bronchoscopes for pediatric indications, and larger gastroscopy, as the cable bundle does not occupy a large space. Cable bundle heights within a spacing of 0.2 mm to 0.6 mm have been found to be a good compromise between compactness, cost, and electrical noise mitigation in most cases.

[0019] In one example of this embodiment, the cable bundle has a width between 0.4 mm and 0.75 mm, for example, 0.60 mm, within a range of 0.2 mm to 0.9 mm. While widths greater than 0.9 mm may be acceptable for some invasive medical devices, such as colonoscopes, it has been found that for most invasive medical devices, cable bundle widths between 0.4 mm and 0.75 mm provide a good compromise between compactness, cost, and electrical noise mitigation.

[0020] In one example of this embodiment, the cable bundle has a height-to-width ratio within a range of 0.55 to 0.75, such as 0.67.

[0021] One embodiment of the present disclosure relates to an invasive medical device, the invasive medical device comprising an endoscope, the endoscope comprising a proximal end having a positioning interface having a distal end, and an insertion cord connected to the distal end of the positioning interface and extending from the distal end, comprising an insertion tube, a bent section, and a tip housing, the insertion cord comprising a camera positioned within the tip housing, a tubular member extending from the positioning interface through the insertion tube to the tip housing, and the bundle extending from the positioning interface to the tip housing.

[0022] In one example of this embodiment, the curved sections include diameters within a range of 1.8 mm to 6.0 mm, for example, 2.5 mm, or within a range of 2.0 mm to 3 mm. The diameter of the curved section is the maximum diameter of the curved section without the potential curved cover. The diameter of the curved section within the specified range is considered a suitable compromise for, for example, bronchoscopes and nasal laryngoscopes.

[0023] In one example of this embodiment, the ratio of the cable bundle height to the diameter of the bent section is less than 0.2, and is, for example, within the range of 0.04 to 0.16, and is approximately 0.1. Ratios greater than 0.2 may be acceptable in some embodiments, such as invasive medical devices without a working channel. However, ratios less than 0.2 are considered advantageous because the cable bundle occupies a relatively small proportion of the cross-section of the bent section, and ratios within the range of 0.04 to 0.16 are considered to be a suitable compromise in practice.

[0024] One aspect of the present disclosure relates to a visualization system comprising an invasive medical device as described above and a video processing device configured to communicate with the invasive medical device in order to receive a video stream from the invasive medical device.

[0025] One or more objectives may be satisfied by aspects of the present invention described in the following embodiments, variations thereof, and examples.

[0026] Those skilled in the art will understand that any one or more of the above aspects of the present disclosure and their embodiments may be combined with any one or more of the other aspects of the present disclosure and their embodiments.

[0027] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. The drawings illustrate embodiments, variations, and examples to facilitate understanding by those skilled in the art and should not be construed as limiting the scope of the set of appended claims.

Brief Description of the Drawings

[0028] [Figure 1] A schematic diagram of an invasive medical device according to the detailed description. [Figure 2] A schematic diagram of an invasive medical device according to the detailed description. [Figure 3] A schematic diagram of an electrosurgical system and a visualization system including an invasive medical device. [Figure 4] A perspective view of an embodiment of an invasive medical device exemplified by an endoscope. [Figure 5] A perspective view of the distal portion of the endoscope of FIG. 4 with the cover removed for illustrative purposes. [Figure 6] A depiction of a cross-sectional view of an embodiment of a bending section of an endoscope including the endoscope shown in FIGS. 4 and 5. [Figure 7] A depiction of a cross-sectional view of an embodiment of a bending section of an endoscope including the endoscope shown in FIGS. 4 and 5. [Figure 8] A depiction of a cross-sectional view of an embodiment of a bending section of an endoscope including the endoscope shown in FIGS. 4 and 5. [Figure 9] A depiction of a cross-sectional view of an embodiment of a bending section of an endoscope including the endoscope shown in FIGS. 4 and 5. [Figure 10] Figures 4 and 5 depict cross-sectional views of an embodiment of the bent section of an endoscope, including the endoscope shown. [Figure 11] This is a plan view of another embodiment of an invasive medical device, exemplified by a dual-lumen tube. [Figure 12] This is a cross-sectional view of another embodiment of an invasive medical device, exemplified by a dual-lumen tube. [Figure 13] Figures 1 to 12 are perspective views of embodiments of image processing devices that can operate with invasive medical devices. [Figure 14] Figures 1 to 12 are plan views of an embodiment of an image processing device that can operate with the invasive medical devices shown. [Figure 15] This is a schematic cross-sectional view of a dual-core axle cable. [Figure 16] This is a schematic diagram of the dual-core cable shown in Figure 15, which is incorporated into the diagram in Figure 2. [Figure 17] Figure 2 is a schematic diagram of an alternative wiring configuration for the dual-coax cable shown in Figure 15, which is incorporated into the diagram. [Modes for carrying out the invention]

[0029] As used herein, the term “distal” generally refers to a direction or location toward the target site, and the term “proximal” generally refers to a direction or location away from the target site.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art. In case of any conflict, this specification, including its definitions, shall prevail. Preferred methods and materials are shown below, but similar or equivalent apparatus, methods, and materials may be used in practice or testing. The materials, methods, and examples disclosed herein are illustrative and not intended to limit the scope of use.

[0031] As described herein, an invasive medical device may include a tubular member defining a lumen inside a proximal end and a distal end spaced apart from the proximal end, the tubular member extending from the proximal end to the distal end, a camera and at least one light source located at the distal end, and a cable bundle consisting of a first coaxial cable and a second coaxial cable in a common electrical shield, the cable bundle extending from the proximal end to the distal end and electrically connected to the camera and light source at the distal end, wherein the first coaxial cable comprises a central conductor of the first cable, a first cable insulation layer and a shield of the first cable, and the second coaxial cable comprises a central conductor of the second cable and a second cable The device comprises an insulating layer and a shield for a second cable, wherein one of the shields for the first cable or the second cable is configured to be electrically connected to a light source and to supply power, the other of the shields for the first cable or the second cable is configured to be electrically connected to a camera and to supply power to the camera, one of the central conductors for the first cable or the second cable is configured to be electrically connected to the camera and to transmit video signals, the other of the central conductors for the first cable or the second cable is configured to be electrically connected to the camera and to transmit clock signals, and a common electrical shield electrically connects the camera and the light source to ground. The invasive medical device may include an endoscope.

[0032] Advantageously, the invasive medical devices described above mitigate electrical noise, whether or not they have a tubular component defining the lumen internally. Electrical noise may be crosstalk and / or generated by electrosurgical tools (ESTs) or other electromagnetic fields. Electrical noise may also be emissions from the invasive medical device itself, which can lead to issues in complying with electromagnetic compatibility (EMC) regulations. Video signal conductors can transmit digital or analog video data. Video signal conductors can also transmit control signals in addition to video signals.

[0033] A bundle consisting of two coaxial cables may be enclosed in an electrical shield. The electrical shield may be electrically disconnected at the distal end of the bundle. The bundle has a proximal end. The electrical shield may be grounded only at the proximal end of the bundle.

[0034] Having provided a general overview of invasive medical devices, we now turn our attention to a more detailed description of embodiments of such invasive medical devices.

[0035] Figures 1 and 2 are schematic diagrams of one embodiment of a visualization system 20, which includes an image processing device 30 electrically connected to an invasive medical device 40 by a cable 42 and a cable connector 44. Examples of invasive medical devices 40 include endoscopes (described with reference to Figures 4-10), dual-lumen tubes (described with reference to Figures 11 and 12), and any other devices configured for insertion into the body of a patient, human, or animal, and including a light source at its distal end. Electrosurgical tools ESTs that can be used with the visualization system 20 are also shown. Some of the features of the invasive medical device 40 shown in Figures 1 and 2 are optional features and components. Embodiments of light sources include light-emitting diodes (LEDs or OLEDs) and laser diodes. Laser diodes can emit more light than LEDs or OLEDs and may be advantageous under some conditions, as they can be used to provide the same light intensity from a smaller footprint of the light source or to provide more light, which may have a positive impact on image quality. On the other hand, laser diodes emit coherent, unidirectional light, which may be a disadvantage in some cases. Currently, LEDs are preferred.

[0036] As shown in Figure 2 and described in more detail below, the video processing device 30 comprises a cable connector receiving section 32, an input circuit 34, and a processor 36. Optionally, the VPA 30 may include a housing supporting a display screen connected to the processor 36 and operable to display images provided by the processor 36. A VPA with a display screen is described with reference to Figure 13. A VPA without a display screen is described with reference to Figures 3 and 14. The input circuit 34 may include a deserializer circuit for converting data or signals provided by the camera's image sensor from a series format to a parallel format. The processor 36 may include an FPGA, a CPU, a GPU, or a combination thereof. The FPGA may be programmed to perform video processing to improve the image, and the CPU may be provided to configure a graphical user interface (GUI) and overlay the GUI onto the image. The combined content may be supplied to the FPGA, which may be connected to a video output circuit.

[0037] The invasive medical device 40 has a proximal end 40p and a distal end 40d spaced apart from the proximal end 40p, and comprises a cable 42 and a cable connector 44, an optional positioning interface 46, an optional circuit board 48, and a tubular member 50 having a proximal end 50p, a distal end 50d, and a tubular member wall 52 through which a lumen 54 configured to receive an EST is defined. The tubular member 50 extends from the proximal end 40p to the distal end 40d.

[0038] The invasive medical device 40 also comprises a camera 60, an optional circuit board 62, a light-emitting diode (LED) 64, a cable bundle 70 having a conductor 72 and an electrical shield 74, and a proximal end shield ground 76 (e.g., the connection point of the electrical shield 74 to be grounded). The camera may include an image sensor, a lens, and a lens support coupled to the image sensor. The image sensor may have a cross-section of less than 2.0 mm on each side, preferably less than 1.9 mm on each side. The cable bundle 70 extends from the distal end 50d to at least the proximal end 50p. The cable bundle 70 consists of a first coaxial cable and a second coaxial cable within a common electrical shield 74, the cable bundle extending from the proximal end to the distal end, and electrically connected to the camera and light source at the distal end, the first coaxial cable comprising a central conductor, a first cable insulation layer, and a shield, the second coaxial cable comprising a central conductor, a second cable insulation layer, and a shield, and either the shield of the first cable or the shield of the second cable being electrically connected to the light source The shield of the first cable or the other of the shield of the second cable is configured to supply power, and is configured to supply power, and is configured to supply power, and is configured to supply power, and is configured to supply power, and is configured to supply power, and is configured to supply power, and is configured to supply power, and is configured to supply power, and the central conductor of the first cable or the other of the central conductor of the second cable the central conductor of the first cable or the other of

[0039] As illustrated with reference to Figures 1 and 2, an invasive medical device may comprise a tubular member defining a lumen extending from the proximal end to the distal end. However, an invasive medical device may lack such a lumen. For example, some endoscopes may be used for examination and introduced into the patient through the lumen of another invasive medical device having one or more lumens. The advantages of the electrical noise reduction features described herein are equally applicable to such endoscopes, as electrosurgical procedures may be performed using different tools and systems. In some systems, the EST is introduced through the lumen of the invasive medical device 40. In some systems, the EST is not introduced through the lumen of the invasive medical device 40.

[0040] Figure 3 shows an example of an electrosurgical system 80 comprising two electrodes 82 and 84 that form an electrical pathway 86 through the patient's body. The EST, e.g., electrode 82, may be introduced into the patient through the lumen of a tubular member (not shown). A separate bundle 70 connected to a camera 60 and cable 42 is shown to indicate that the bundle 70 does not necessarily form part of an invasive medical device having a tubular member through which the EST is introduced into the patient. Cable 42 is connected to a VPA 260, described with reference to Figure 14, which includes a detachable display screen 90 and a display screen support 92 configured to be detachable from the VPA 260 and the display screen 90 during normal use. The display screen is operable to present image and video streams generated and transmitted by the camera 60. A VPA 240 (described below) may be used instead of the VPA 260.

[0041] Figures 4 and 5 illustrate one embodiment of an invasive medical device 40, exemplified by an endoscope 140, the endoscope 140 comprising a position interface exemplified by a handle 146, the handle 146 including a steering control unit 148, the steering control unit 148 operable to steer the distal end of the endoscope 140 as known in the art by alternately pulling a steering wire 174 shown in Figure 5 in response to the movement of the steering control unit 148. The endoscope 140 comprises an insertion cord 150 having a proximal end 150p and a distal end 150d, the insertion cord 150 including an insertion tube 152 and a bend section 160. A distal tip comprising an tip housing 170 extends from the bend section 160. A camera 60 is located within the tip housing 170. Alternatively, the camera 60 may be located at least partially within the tip housing 170. The bent section 160 may comprise a single-piece polymer structure with multiple segments 166 between a proximal segment 162 and a distal segment 164 connected to the tip housing 170. The segments are interconnected by polymer strips 168 or hinges, which form a part of the one-piece structure and bend when tension is applied to the steering wire 174. An example of a tubular member 50, a working channel tube 172, provides a lumen 54 for introducing the EST.

[0042] Instead of a single-piece polymer structure, a bent section can also be assembled from multiple pieces. Such an assembly may be formed from two single-piece polymer structures, which are formed by elongating two opposing longitudinal halves of a completed bent section. Such an assembly may also be formed from individual segments assembled via hinges.

[0043] The endoscope 140 may be a single-use device. Single-use devices are low-cost and disposable, and are designed not to be cleaned and sterilized after use, nor to be reused after cleaning.

[0044] A positioning interface functions to control the position of the insertion cord. A handle is an example of a positioning interface, and these terms are used interchangeably unless otherwise specified. A handle also functions to provide a steering control unit for steering the camera's field of view, e.g., a knob, lever, button, etc. Alternatively, a different positioning interface may be provided, connected to the insertion cord and detachably connected to a robotic arm. Thus, the insertion cord extends from the robotic arm, and the invasive medical device is detachable from the robotic arm. The robotic arm rotates, translates, or otherwise positions the proximal end of the insertion cord in response to signals, including voice commands from the operator, as the operator would do manually. The positioning interface may include a control actuator, including a manually controlled actuator. Alternatively or additionally, the control actuator may be provided within or on the robotic arm, or by a robotic system including the robotic arm, thereby potentially reducing the cost of the invasive medical device. An exemplary control actuator includes a single-axis actuator, including a linear motion actuator. The linear motion actuator may include a screw rod connected to the screw nut portion, and a motor rotates the rod to move the nut portion in a parallel direction.

[0045] Figure 6 is a schematic diagram of section AA of the bent section 160, showing a cross-section of one of the segments and a cross-section of the working channel tube 172, lumen 54 or working channel lumen, steering wire 174, steering wire guide tube 176, and cable bundle 70. The bent section 160 has an outer diameter D. The steering wire guide tube 176 surrounds the steering wire 174, which is connected at one end to the end housing 170 and at the other end to the steering control unit 148. The wall of segment 166 (not shown in Figure 6) includes a notch or opening through which the steering cable guide tube 176 passes and a notch or opening for the cable bundle 70. Examples of notches or openings are illustrated and described with reference to Figures 7 to 9. The illustrated cable bundle 70 is non-circular with a flat or rectangular cross-section having a height h and a width w. This is advantageous because the cable bundle 70 can be arranged in the shortest dimension (i.e., height) in the radial direction of the cross section, thereby occupying the smallest proportion of the outer diameter D of the bent section, which allows for the provision of a small outer diameter D or a larger inner diameter d of the lumen 54 (both are desirable).

[0046] A sleeve or bend cover (not shown) may be provided on the bend section 160 to fluidly seal the space between adjacent segments 166. The outer diameter of the segments 166 may be substantially the same as or identical to the outer diameter of the tip housing 170. In some embodiments, the outer diameter is less than 4.2 mm, less than 3.6 mm, less than 3.4 mm, less than 3.2 mm, and even less than 3.0 mm, with a minimum outer diameter of 1.8 mm.

[0047] In modified form A of this embodiment, the wall thickness of the working channel tube is 0.10 mm or more and 0.20 mm or less, preferably 0.12 mm or more and 0.18 mm or less, more preferably about 0.15 mm, and the outer diameter of the working channel tube is 2.0 mm or more and 3.0 mm or less, preferably 2.20 mm or more and 2.80 mm or less, more preferably 2.40 mm or more and 2.60 mm or less.

[0048] In modified form B of this embodiment, the minimum dimension of the cable bundle 70 is 0.40 mm or more and 0.56 mm or less, preferably 0.44 mm or more and 0.52 mm or less, more preferably 0.45 mm or more and 0.50 mm or less, and the outer diameter of the work channel tube is 2.0 mm or more and 3.0 mm or less, preferably 2.20 mm or more and 2.80 mm or less, more preferably 2.40 mm or more and 2.60 mm or less.

[0049] In modified form C of this embodiment, the inner diameter of the insertion tube is less than 3.8 mm, or less than 3.4 mm, or less than 3.0 mm.

[0050] The variations of this embodiment can be combined to form additional variations of the embodiment. Thus, variation A may be combined with variation B to form a new variation, variation A may be combined with variation C to form a new variation, variation A may be combined with variations B and C to form a new variation, and variation B may be combined with variation C to form a new variation.

[0051] Figures 7 to 10 provide examples of segment walls provided to maintain the separation of the steering wire 174 and secure the bundle 70 to the bent section 160. Figure 7 shows, for example, a common opening 180 defining a working channel tube opening 182, a steering wire notch 184 (cut out from around the working channel tube opening 182), and a bundle notch 186. Providing a notch around the working channel tube opening 182 allows for a reduction in the diameter and an increase in the flexibility of the bent section 160. Figure 8 shows another example of the opening 180 in the bent section 190. In this example, the opening 180 includes three notches for the steering wire 174 and the bundle 70, as in Figure 7. Due to its relatively large cross-sectional area compared to the cross-section of the bundle 70, an additional tube may be provided in the notch 186. Figure 9 shows an example of a common opening 180' in the bent section 192. In this example, the opening 180' includes a notch for the bundle 70 and optionally for other tubes or components, as well as an opening 176' for the steering wire 174, as in Figure 7. Additional tubes may be provided in the notch 186 due to its larger cross-sectional area compared to the cross-section of the bundle 70. Figure 10 shows an example of a common opening 180 in a bent section 194. The bent section 194 differs from the bent section 192 in that it has a notch instead of an opening for the steering wire 174. As used herein, a common opening refers to an opening that accommodates the work channel tube and one or more of the steering wire and bundle. As illustrated, the accommodation of the steering wire and bundle is provided by the notch. The openings for the work channel tube, steering wire and bundle may also be provided via individual openings instead of a common opening, if the size is acceptable.

[0052] The camera 60 may have a cross-section of less than 2.0 mm on each side. The outer diameter of the tip housing 170 may be about 3.0 mm, preferably about 2.8 mm, and more preferably 2.8 mm or less. The term "about" is intended to define a range of + / - 10% from the specified number.

[0053] As the dimensions of the camera and bending sections are continuously reduced for the benefit of the patient, the size of the wires and cables increases by a certain percentage of the cross-section. To continue reducing size and cost, it is helpful to identify the cable configuration, which includes wires, shielding, jackets, etc., and use smaller wires while still avoiding the adverse effects of electrical noise. The success of the mitigation efforts depends on the image sensor and deserializer used, the length of the bundle, and the structure surrounding it.

[0054] Figures 11 and 12 illustrate another embodiment of the invasive medical device 40, exemplified by a dual-lumen tube 200. Figure 12 shows a cross-section BB of the tube 200. The dual-lumen tube 200 comprises a tubular member 200a having a surrounding (or circumferential) wall 201 that defines a first lumen 202 and an illumination lumen 208 internally. The camera 60 and LED 206 are positioned in the illumination lumen 208 located in the wall of the tube 200.

[0055] A dual-lumen tube may be, for example, an endobronchial tube or an endotracheal tube. The dual-lumen tube 200 may also have a second lumen 204. The surrounding wall 201 may consist of a first portion 210 and a second portion 212, which are divided by an intermediate wall 214. An inflatable cuff 220 is provided at the distal end and is connected via an inflation lumen (not shown) to an inflation tube 222 which can be connected to a pump to inflate the cuff 220. Similar to the endoscope 140, it is desirable to reduce the size of the device and increase its flexibility, for example by reducing the wall thickness of the tube, which requires a reduction in the size of the camera 60 and the bundle 70. Although not shown, the bundle 70 is located in the illumination lumen 208 and connects the camera 60 to a cable connector 44 so as to be communicative. A single-lumen tube may also include the features described herein, including a first lumen 202 and a camera 60, LED 206, and bundle 70 located in the illumination lumen 208 situated in the wall of the tube 200.

[0056] A VPA240 having a display screen 244 is shown in Figure 13. The VPA240 includes a housing 242 and one or more cable connector receptacles 246 configured to receive a cable connector 244. The housing 242 supports the display screen 244, which is called an "integrated" display screen, in contrast to a "detachable" display screen, and is assembled with the display screen 244 as one piece. The terms "integrated" and "detachable" reflect the assembled form of the device when in use, as opposed to an unassembled or disassembled form of the device. A VPA260 without a display screen 244 is shown in Figure 14, and the VPA260 with a detachable display screen 90 was previously shown in Figure 3. The VPA260 includes a housing 262 and one or more cable connector receptacles 246 configured to receive a cable connector 44. In both the VPA240 and VPA260, detachable display screens may be communicably connected to them via Ethernet, wireless, AVI, HDMI, or other data interfaces, as known in the art. When an intrusive medical device 40 is connected, the VPA240 or 260 presents an image or video stream on an integrated and / or detachable display screen, as known in the art.

[0057] The above description described an invasive medical device comprising a bundle of two coaxial cables with a common shield, the bundle having a proximal end and a distal end spaced apart from the proximal end, a camera positioned at the distal end, and the bundle extending from the proximal end to the distal end and electrically connected to the camera at the distal end. In some embodiments, the invasive medical device includes a tubular member defining a lumen inside, the tubular member extending from the proximal end to the distal end of the device, but not in other embodiments. The two coaxial cables have a total of five conductors, including a ground conductor, a camera power conductor, an illumination power conductor, a clock conductor, and a video signal conductor. Embodiments of the bundle 70 are described below.

[0058] Now, let us turn our attention to one embodiment of the bundle 70 shown in Figure 15. The bundle 70 comprises a first coax cable 308 and a second coax cable 310 arranged within a common shield 74. The first coax cable 308 comprises a central conductor 312, an insulator 304, and a shield 314. The insulator may be, for example, a perfluoroalkoxy. The central conductor 312 may be a wire or a stranded wire comprising two or more strands, for example, seven strands. The shield of the first coax cable 308 may be formed of a braid of wires or a spiral wire around the insulator. The shield 314 is conductive and constitutes the conductor 72. Preferably, the shield is not formed of aluminum foil, because the electrical resistance of such aluminum foil is considered to be too high to efficiently constitute a conductor in this disclosure. Similarly, the second coax cable 310 comprises a central conductor 316, an insulator 304, and a shield 318. The central conductor may be a wire or a stranded wire comprising two or more strands. The shield 318 of the second Coax cable 310 may be formed of a braid of wires or a spiral wire around an insulator. The shield 318 is conductive and constitutes the conductor 72. Preferably, the shield is not formed of aluminum foil, as the electrical resistance of such aluminum foil is considered to be too high to efficiently constitute the conductor in this disclosure. The Coax cable may have an insulator 304 disposed on the outer surface of the shield. The insulator may be a lacquer, which allows for a very compact cable bundle, but such lacquers are generally brittle and can degrade during assembly or use of invasive medical devices. Therefore, currently, providing a coating of, for example, perfluoroalkoxy (PFA), polyethylene (PE), or polypropylene (PP) on the Coax cable is considered a better option.The first and second coax cables may be identical, which provides simplicity and potentially lower costs, but they may differ if it is considered beneficial, for example, considering increased shielding of one or the other conductor, or if one or more conductors are exposed to concerns regarding electrical resistance. The common shield 74 may be formed of a braid of wire, spiral wire, or a wrap or foil such as tinned copper wrap. The common shield 74 is conductive and electrically connected to earth. The common shield 74 may have two layers, such as two braids overlapping each other, to increase the strength and robustness of the cable bundle, which may be advantageous for handling during manufacturing. The common shield may have an insulator, such as a jacket 306 of insulating material. The insulator may be a protective sleeve or jacket 306 that provides strength to the bundle to allow the use of smaller gauge wires. Alternatively, the insulator may be lacquer, which allows for very compact cable bundles, but increases the risk of wire breakage or deterioration of the lacquer coating during manufacturing or use, all of which can lead to loss of live images or adverse effects on image quality. Wires are selected based on their current-carrying capacity and physical strength, and therefore may be larger or smaller depending on their function. To reduce the size of the tubular member and increase its flexibility, it is desirable to use the smallest wire that can perform the selected function. Therefore, one wire may be larger than the other. Wire resistance, and therefore voltage drop over the length of the wire, is another limiting factor in some functions. For example, if the wire diameter is too small, the voltage drop may be too large, which can lead to image degradation in the video signal conductors of the bundle. The inventors have found that certain combinations of wire, shield, and conductor placements result in remarkably good electrical noise mitigation, for example, clock-to-video signal crosstalk, although these are not necessarily mutually exclusive.

[0059] The cable bundle 70 shown in Figure 15 is operable with an image sensor equipped with four connection pads. Such an image sensor and pad configuration has been developed to reduce the size of the image sensor. The bundle 70, consisting of two Coax cables 308, 310 within a common shield 74, allows for a very compact cable bundle structure with a flat configuration having a height h of approximately half its width w. The low height h means that the cable bundle 70 can be incorporated into an endoscope with little effect on its diameter, so the flat configuration of the cable bundle 70 can be an advantage in some endoscopic structures. Thus, reducing the bundle profile is beneficial to reduce the cross-sectional area of ​​the invasive medical device 40 and to benefit from the use of smaller cameras.

[0060] Figure 16 is a schematic diagram of the cable bundle 70 in the embodiment of Figure 15 according to Modification A. The first coax cable 308 comprises the two conductors 72 described above, namely, a central conductor 312 electrically connected to the camera in this modification and carrying the video signal conductor V-out, while the shield 314 is electrically connected to the light source and configured to supply power to the light source. The second coax 310 comprises the two conductors described above. The central conductor 316 is electrically connected to the camera and configured to transmit the video clock signal CLK, while the shield 318 is electrically connected to the camera and configured to supply power to the camera VCC. The common shield 74 electrically connects both the camera and the LED to earth GND. This setup greatly reduces crosstalk between the clock signal and the video signal, in that both signals are protected by the shield. Furthermore, since the signals are protected by the common shield 74 and the individual shields of the two coax cables 308, 310, HF noise from, for example, electrosurgical tools is greatly reduced.

[0061] Modification B is shown in the schematic diagram of the cable bundle 70 in the embodiment of Figure 15. The first coax cable 308 comprises the two conductors described above, namely, a central conductor 312 configured to be electrically connected to the camera and transmit the video clock signal CLK in this modification, and a shield 314 configured to be electrically connected to the light source and supply power to the LED. The central conductor 316 of the second coax 310 is configured to be electrically connected to the camera and transmit the video signal V-out, while the shield 318 is configured to be electrically connected to the camera and supply power to the camera VCC. A common shield 74 electrically connects the earth GND to both the camera and the LED. This setup greatly reduces crosstalk between the clock signal and the video signal, in that both signals are also protected by the shield. Furthermore, since the signals are protected by the common shield 74 and the individual shields of the two coax cables 308, 310, HF noise from, for example, electrosurgical tools is greatly reduced. Modification B may be advantageous when the illumination intensity is changed by increasing or decreasing the LED power, particularly when the illumination intensity is controlled by pulsating LED power. Changing the LED power, especially pulsating LED power, can introduce electrical noise to the central conductor. Since the video signal V-out is generally considered to be more sensitive to electrical noise than the clock signal CLK, it is considered advantageous to provide the LED power and video signal V-out on different coax cables.

[0062] The central conductor of a Coax cable should be as small as possible to provide a low profile for the cable, taking into account the increasing conductor resistance as the conductor cross-section decreases. The central conductor may be a single wire or two or more strands that make up that wire. A wire size of the central conductor in the range of 40 to 44 American wire gauge (AWG) is generally considered a good compromise for this embodiment, but in other embodiments, it may be a larger wire, e.g., 38AWG wire, or a smaller wire, e.g., 46AWG, 48AWG, or even 50AWG wire. 40AWG corresponds to a wire outer diameter of 0.079 mm for a single wire, while 44AWG corresponds to a wire outer diameter of 0.051 mm for a single wire, corresponding to conductor resistances of, for example, 3.8 ohms / m and 9.1 ohms / m, respectively. The diameter of the central conductor is larger in the case of a multi-strand type. Conductor resistance also depends on the conductor material (e.g., copper or a special alloy), whether it is a single wire or composed of strands, and whether the wire or strands of wire are additionally plated, for example, with tin or silver. The outer diameter of a Coax cable also depends on the thickness of the insulation, etc. Examples of Coax cable outer diameters are 0.33–0.37 mm for a 40AWG 7-wire center conductor and 0.22–0.24 mm for a 46AWG 7-wire center conductor. Stranded wires are more flexible but occupy more space than single wires.

[0063] In one example of modification B, the first coax cable 308 is larger than the second coax cable 310. In one example, the first coax cable 308 is at least 42 American wire gauge (AWG) wire, and may be larger, for example, 40 AWG wire, while the second coax cable 310 is at most 44 AWG wire, preferably 46 AWG wire. The wire gauge may also be based on the length of the cable. If the image sensor cable (inside the device) is 300 mm or less, a thinner gauge may be used than if the cable is longer.

[0064] In a further variant C of this embodiment, the conductors include conductors of the same type and size.

[0065] The variations of this embodiment can be combined to form additional variations of the embodiment. Therefore, variations A and B may be combined with variation C to form a new variation.

[0066] In one variant, a single conductor is used as a shared power line to the LED and camera, thereby avoiding the need for separate power conductors for the camera and LED. However, since the power required for the camera and LED is often different, the shared power line requires the provision of a voltage regulator or other power-splitting means to divide the power supplied to the camera and LED by the shared power line. Avoiding power-splitting means at the distal end of an invasive medical device also allows for a reduction in the size of the invasive portion of the medical device, such as the distal end. A separate power conductor for the LED also facilitates the on / off switching or potentially adjustment of pulsating power to adjust the illumination, which can have a positive effect on image quality.

[0067] The isolation of the video signal from the clock conductor provided sufficient electrical noise mitigation from crosstalk from the clock signal. The video signal conductor can be used to transmit analog output signals from the camera and control signals between the camera and the VPA. The analog output signals include video frames and images. The control signals are provided via a serial peripheral interface (SPI) and may be multiplexed with the analog signals and may include gain and exposure camera settings.

[0068] The electrical shield can be electrically disconnected at the distal end of the bundle. The bundle has a proximal end. The electrical shield can be grounded only at the proximal end of the bundle. The electrical shield can be constructed of braided or spiral wire. Other types of electrical shields may also be used.

[0069] The size (e.g., diameter) of uninsulated wire ranges from 36AWG to 50AWG. As is well known, AWG stands for American Wire Gauge Standard. Wire dimensions are given by ASTM standard B258 (ASTM B258-18). The AWG table is for single, round solid conductors. The AWG of stranded wire is determined by the cross-sectional area of ​​an equivalent solid conductor. Because there are small gaps between the strands, stranded wire always has a slightly larger overall diameter than a solid wire of the same AWG. A 36AWG wire has, for example, an outer diameter of 0.127 mm. A 32AWG wire has an outer diameter of 0.202 mm. A 40AWG wire has an outer diameter of 0.080 mm. A 42AWG wire has an outer diameter of 0.063 mm. A 44AWG wire has an outer diameter of 0.050 mm. A 46AWG wire has an outer diameter of 0.040 mm. For example, the insulation thickness of a 40AWG wire is 0.040 mm, the shield thickness (braided) is 0.020 mm, the outer insulation on the shield is 0.030 mm, the outer shield is 0.060 mm (double braided), and the outer jacket is 0.080 mm. The total outer width of the cable bundle is 0.800 mm, and the height is 0.540 mm.

[0070] Generally, all wire sizes are up to 38 AWG, and may be 38, 40, 42, 44, 46, 48, or 50 AWG. Smaller gauge wires can help reduce the cross-sectional size of the invasive portion of the invasive medical device and increase its flexibility, but at the expense of noise sensitivity. When size reduction is not required, heavier gauge wires may be preferable.

[0071] Tests were conducted to check the susceptibility of an intrusive medical device to electrical noise generated by electrosurgical tools. This test determined the high-frequency (HF) immunity of a 1m long dual-coax shielded cable, 44AWG. The electrosurgical tool used was an ERBE VIO® 3 with an APC3 module and FIAPC 2200A probe, 3.2mm in diameter, and 2.2m in length (5kVp). The cable performed well without interference, resulting in good image quality.

[0072] Previous tests on other wire types revealed interference issues. For example, tests were conducted on a single wire (non-coaxial). The problem was found to involve interference not only to the video signal but also to the camera power supply. In the tests, the camera power supply was 3.42V DC, but interference was found to affect the voltage measured at the camera tip, so the measured voltage ranged from 1.88V to 4.98V. The camera requires a minimum of 3.14V for normal operation, and the low of 1.88V was measured for only a short time (about 4ns), but this was sufficient to trigger and restart the camera. This camera reset and restart resulted in flicker in the image.

[0073] Although several embodiments have been described and illustrated in detail, the present invention is not limited thereto and can be embodied in other ways within the scope of the subject matter defined in the following claims. In particular, it should be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention.

[0074] In a device claim that lists several means, some of these means may be embodied by the exact same hardware components. The mere fact that certain measures are listed in different dependent items or described in different embodiments does not imply that combinations of these measures cannot be used advantageously.

[0075] The terms “first,” “second,” and so on in this specification and the claims are used to distinguish similar elements, if any, and are not necessarily intended to describe a specific sequential or chronological order. Any terms used in this manner should be understood to be interchangeable under appropriate circumstances, so that the embodiments described herein may operate, for example, in an order other than those illustrated or otherwise described herein.

[0076] It should be emphasized that the terms “comprises / comprising” are generally interpreted as open-ended terms that specify the presence of a described feature, integer, step, or component, but do not exclude the presence or addition of one or more other features, integers, steps, components, or groups thereof. The terms “consisting of” or “consists of” are closed terms and include only the components, structures, steps, etc., specifically listed with such terms, as well as those subject to U.S. Patent Law. [Explanation of Symbols]

[0077] TIFF2026086339000002.tif252170TIFF2026086339000003.tif253170TIFF2026086339000004.tif25170

Claims

1. A proximal end (40p) and a distal end (40d) spaced apart from the proximal end, A tubular member (50) that defines a lumen (54) inside, wherein the tubular member (50) extends from the proximal end to the distal end, The camera (60) and light source located at the distal end, A cable bundle (70) consisting of a first coaxial cable (308) and a second coaxial cable (310) within a common electrical shield (74), wherein the cable bundle extends from the proximal end to the distal end and is electrically connected to the camera and the light source at the distal end. An invasive medical device comprising, The first coaxial cable (308) comprises a central conductor (312) of the first cable, a first cable insulation layer, and a shield (314) of the first cable. The second coaxial cable (310) comprises a central conductor (316) of the second cable, a second cable insulation layer, and a shield (318) of the second cable. Either the shield of the first cable or the shield of the second cable is configured to electrically connect to the light source and supply power to it. The other of the shield of the first cable or the shield of the second cable is configured to electrically connect and power the camera. The central conductor of the first cable or the central conductor of the second cable is configured to electrically connect to the camera and transmit video signals. The other of the central conductors of the first cable or the second cable is configured to electrically connect the camera and transmit a clock signal. An intrusive medical device wherein the common electrical shield (74) electrically connects the ground to the camera and the light source.

2. The invasive medical device according to claim 1, wherein the coaxial cable is not twisted together.

3. The invasive medical device according to claim 1 or 2, wherein the shield of the first cable is configured to electrically connect to the light source and supply power, the central conductor of the first cable is configured to electrically connect to the camera and transmit the video signal, the shield of the second cable is configured to electrically connect to the camera and supply power, and the central conductor of the second cable is configured to electrically connect to the camera and transmit the clock signal.

4. The invasive medical device according to claim 1 or 2, wherein the shield of the first cable is configured to electrically connect to and supply power to the light source, the central conductor of the first cable is configured to electrically connect to the camera and transmit the clock signal, the shield of the second cable is configured to electrically connect to and supply power to the camera, and the central conductor of the second cable is configured to electrically connect to the camera and transmit the video signal.

5. The aforementioned coaxial cable is 0.0005 mm ２ ~0.0050 mm ２ Within the interval, for example, 0.0008 mm ２ ~0.0032 mm ２ Within the interval, for example, 0.0012 mm ２ An invasive medical device according to any one of claims 1 to 4, which is a microcoaxial cable having the maximum cross-sectional area of ​​the central conductor.

6. The invasive medical device according to any one of claims 1 to 5, wherein the cable bundle has heights within intervals of 0.1 to 0.7 mm, for example, 0.35 mm, or within intervals of 0.2 mm to 0.6 mm.

7. The invasive medical device according to any one of claims 1 to 6, wherein the cable bundle has a width within an interval of 0.2 mm to 0.9 mm, for example, 0.60 mm, or within an interval of 0.4 mm to 0.75 mm.

8. The invasive medical device according to claim 6 or 7, wherein the cable bundle has a height-to-width ratio within an interval of 0.55 to 0.75, such as 0.

67.

9. The aforementioned invasive medical device includes an endoscope, and the endoscope is A proximal end having a positioning interface (146) with a distal end, An insertion cord (150) connected to the distal end of the positioning interface, extending from the distal end, comprising an insertion tube (152), a bent section (160), and a tip housing (170), wherein the camera is positioned within the tip housing, and the tubular member extends from the positioning interface through the insertion tube to the tip housing. An invasive medical device according to any one of claims 1 to 8, wherein the bundle extends from the positioning interface to the tip housing.

10. The invasive medical device according to claim 8, wherein the bent section includes a diameter within an interval of 1.8 mm to 6.0 mm, for example, 2.5 mm, or within an interval of 2.0 mm to 3 mm.

11. The invasive medical device according to claims 5 and 10, wherein the ratio of the height of the cable bundle to the diameter of the bent section is less than 0.2, and is, for example, within the interval of 0.04 to 0.16, and for example, approximately 0.

1.

12. An invasive medical device (40, 140, 200) according to any one of claims 1 to 11, A video processing device (30) configured to communicate with the invasive medical device in order to receive a video stream from the invasive medical device, and A visualization system (20) equipped with the following features.

Images