Pull wire slack detection and adjustment for flexible elongate devices

Abstract

Methods and systems for identifying slack in a pull wire coupled to an engageable body portion of a flexible elongate device include a control system that determines a minimum tension for the pull wire based on bending parameters of the flexible elongate device.

Description

Technical Field

[0001] The disclosed embodiments relate to systems and methods for flexible elongation devices. Background Technology

[0002] Minimally invasive medical techniques aim to reduce the amount of tissue damaged during medical procedures, thereby reducing patient recovery time, discomfort, and harmful side effects. Such techniques can be performed through natural openings in the patient's anatomy or through one or more surgical incisions. Through these natural openings or incisions, physicians can insert minimally invasive medical instruments (including surgical, diagnostic, therapeutic, and / or biopsy instruments) to reach target tissue locations. One such technique utilizes flexible and / or steerable elongated devices (e.g., flexible catheters) that can be inserted into an anatomical channel and navigated toward regions of interest within the patient's anatomy. Summary of the Invention

[0003] The following presents a brief overview of the various examples described herein and is not intended to identify key or important elements or to depict the scope of the claims.

[0004] According to a first example, a medical system is described that includes a flexible elongation device comprising a pair of traction wires configured to control engagement of the flexible elongation device along an axis. The medical system also includes an actuator coupled to the pair of traction wires and configured to apply tension to the pair of traction wires. A control system of the medical system is configured to: determine bending parameters of the flexible elongation device based on data from one or more sensors; and adjust the minimum tension applied to the pair of traction wires by the actuator based on the bending parameters.

[0005] According to a second example, a medical system is described that includes a flexible elongation device having an engageable body portion and a pair of traction wires configured to control engagement of the engageable body portion along an axis. The medical system also includes: one or more sensors associated with the flexible elongation device; sensors coupled to the pair of traction wires and configured to apply tension to the pair of traction wires; and a control system. The control system is configured to: determine measurement parameters of the engageable body portion based on data from one or more sensors; determine estimated parameters of the engageable body portion based on the states of one or more actuators; identify slack in at least one of the pair of traction wires based on a comparison of the measurement parameters and the estimated parameters; and adjust a minimum tension for the pair of traction wires in response to identifying slack.

[0006] It should be understood that both the foregoing general description and the following detailed description are exemplary and illustrative in nature and are intended to provide an understanding of this disclosure without limiting its scope. In this regard, additional aspects, features, and advantages of this disclosure will be apparent to those skilled in the art from the following detailed description. Attached Figure Description

[0007] Figure 1 This is a simplified diagram of a medical system based on some implementation methods.

[0008] Figure 2A This is a simplified diagram of a medical device system according to some implementation methods.

[0009] Figure 2B This is a simplified diagram of a medical device including a medical tool within an elongation device, according to some embodiments.

[0010] Figure 3A and Figure 3B This is a simplified side view of a medical device mounted on an insertion assembly in patient coordinate space, according to some embodiments.

[0011] Figure 4 This is a simplified diagram of a medical system based on some implementation methods.

[0012] Figure 5 This is a flowchart illustrating a first example method for determining the minimum tension for a medical system according to some embodiments.

[0013] Figure 6 This is a flowchart illustrating a second example method for determining the minimum tension for a medical system according to some embodiments.

[0014] The embodiments and advantages of this disclosure can be better understood by referring to the following detailed description. It should be understood that the same reference numerals are used to identify the same elements shown in one or more of the accompanying drawings, which are shown for illustrative purposes only and not for limiting the embodiments of this disclosure. Detailed Implementation

[0015] In the following description, specific details of some embodiments consistent with this disclosure are set forth. Numerous specific details are set forth to provide a thorough understanding of the embodiments. However, it will be apparent to those skilled in the art that some embodiments may be practiced without some or all of these specific details. The specific embodiments disclosed herein are intended to be exemplary and not restrictive. Other elements within the scope and spirit of this disclosure can be implemented by those skilled in the art, although not specifically described herein. Furthermore, to avoid unnecessary repetition, one or more features shown and described in association with one embodiment may be incorporated into other embodiments unless otherwise specifically described or if one or more features would render the embodiment inoperable. In some cases, well-known methods, processes, components, and circuits have not been described in detail to avoid unnecessarily obscuring aspects of the embodiments.

[0016] This disclosure describes various instruments and parts thereof based on their state in three-dimensional space. As used herein, the term “position” refers to the location of an object or part of an object in three-dimensional space (e.g., three translational degrees of freedom along Cartesian x, y, and z coordinates). As used herein, the term “orientation” refers to the rotational placement of an object or part of an object (e.g., one or more rotational degrees of freedom, such as roll, pitch, and yaw). As used herein, the term “pose” refers to the position of an object or part of an object in at least one translational degree of freedom and the orientation of the object or part of an object in at least one rotational degree of freedom (e.g., up to six total degrees of freedom). As used herein, the term “shape” refers to the set of poses, positions, and / or orientations measured along an object. As used herein, the term “distal” refers to a location closer to the procedural site, and the term “proximal” refers to a location further away from the procedural site. Thus, when an instrument is designed to perform a process, the distal portion or distal end of the instrument is closer to the procedural site than the proximal portion or proximal end of the instrument.

[0017] Flexible elongation devices (such as catheters, endoscopes, or other types of flexible instruments) can be manipulated within a patient to reach a desired treatment location. One type of flexible elongation device includes one or more pairs of opposing traction wires that can be tensioned to control engagement of the engageable body portion (e.g., distal segment) of the flexible elongation device along an axis (e.g., pitch and / or yaw). The tension in the traction wires is controlled by the operation of one or more actuators to increase and decrease the tension on the traction wires. Each pair of traction wires can use antagonistic actuation to control engagement along an axis. Here, the actuators apply a minimum tension to the paired opposing traction wires, which corresponds to the lowest tension maintained on the paired traction wires. When the paired traction wires are at (e.g., the same) minimum tension, the engageable body portion is in a neutral (e.g., straight) position. To perform engagement along an axis controlled by paired traction lines, the passive traction line can be maintained at minimum tension, while the active traction line changes its tension (e.g., increases or decreases, but remains at a level above or equal to the minimum tension) to induce engagement. For example, when the engageable body portion bends in a certain direction, the active traction line on the side of the engageable body portion corresponding to the bending direction has increased tension, while the passive traction line on the opposite side of the engageable body portion remains at minimum tension. When the engageable body portion is straightened from the bending direction, the active traction line can have decreased tension, while the passive traction line can be set to minimum tension (or higher tension, but not lower than the minimum tension). The use of a minimum tension control scheme helps reduce slack in the traction line system, increases the responsiveness of actuator control, and facilitates the efficient return of the engageable body portion from a more bent configuration to a straighter configuration.

[0018] When a flexible elongating device is inserted into a patient, any bend deviating from its straight neutral axis will cause the traction wire to engage with the surfaces of the flexible elongating device (e.g., the inner surface of the lumen, axial support structures, etc.), resulting in friction. Accumulated frictional forces can arise from tortuous paths within the patient's anatomy, and slack can develop in the traction wire when these frictional forces counteract the tension applied to the traction wire by the actuator. While minimum tension can help reduce slack in the system, accumulated friction can produce undesirable slack, as this can degrade controller performance or lead to incorrect position estimation when using a motor encoder for position control. Higher minimum tension is desirable to counteract the dynamic changes in slack during the operation of the flexible elongating device. However, high minimum tension can stress the traction wire and reduce the lifespan of the flexible elongating device. Therefore, as illustrated herein, dynamic adjustment of the minimum tension during the process can be advantageous than using a static, predefined minimum tension for the entire process.

[0019] The methods and systems disclosed herein detect or predict traction line slack and increase the minimum tension on the traction line to reduce or eliminate slack or otherwise counteract its effects. Slack in the system can be identified or predicted in a variety of suitable ways. Typically, slack accumulation is a function of the shape of the flexible elongation device, where a larger amount of bending corresponds to increased friction and slack. In one example, slack can be determined by comparing the bending angle of the engageable body portion (e.g., as indicated by a shape sensor of the flexible elongation device) with an estimated bending angle of the engageable body portion indicated by encoder data from one or more actuators controlling the tension of the traction line. The difference between a bending angle greater than a predetermined threshold and the estimated bending angle can be used to indicate slack in the traction line. In other examples or additional examples, traction line slack can be estimated based on the shape of the flexible elongation device. The shape of the flexible elongation device may correspond to the number and / or severity of bending along the flexible elongation device, the bending angle of the engageable body portion, and / or the insertion length of the flexible elongation device. The shape of the flexible elongation device can be determined from data from one or more sensors, including shape sensors, position sensors, current sensors, torque sensors, etc.

[0020] Figure 1 This is a simplified diagram of a medical system 100 according to some embodiments. The medical system 100 can be applied to procedures such as surgery, diagnosis (e.g., biopsy), or treatment (e.g., ablation, electroporation, etc.). While some embodiments of such procedures are provided herein, any references to medical or surgical instruments and methods are non-limiting. The systems, instruments, and methods described herein can be used with animal or human cadavers, animal carcasses, parts of human or animal anatomy, non-surgical diagnostics, and in industrial systems, general-purpose or special-purpose robotic systems, general-purpose or special-purpose remote operating systems, or robotic medical systems.

[0021] like Figure 1As shown, the medical system 100 may include a manipulator assembly 102 that controls the operation of a medical device 104 during various procedures performed on a patient P. The medical device 104 may extend through an opening in the patient P's body to an internal location within the patient P's body. The manipulator assembly 102 may be a remotely operated, non-remotely operated, or hybrid remotely and non-remotely operated assembly, having one or more degrees of freedom of motion that can be electrically operated and / or one or more degrees of freedom of motion that can be non-electrically operated (e.g., manually operated). The manipulator assembly 102 may be mounted to and / or positioned near the patient table T. A master assembly 106 enables an operator O (e.g., a surgeon, clinician, internist, or other user) to control the manipulator assembly 102. In some examples, the master assembly 106 enables the operator O to view the procedure site or other graphical or information displays. In some examples, the manipulator assembly 102 may be excluded from the medical system 100, and the device 104 may be directly controlled by the operator O. In some examples, the manipulator assembly 102 can be manually controlled by an operator O. Direct operator control may include various handles and operator interfaces for handheld operation of the instrument 104.

[0022] The main component 106 may be located at a surgeon's console near the patient table T where the patient P is located (e.g., in the same room as the patient table T), such as at the side of the patient table T. In some examples, the main component 106 is located away from the patient table T, such as in a different room or a different building. The main component 106 may include one or more control devices for controlling the manipulator component 102. The control devices may include any number of various input devices, such as joysticks, trackballs, rollers, steering pads, buttons, data gloves, trigger guns, manual controllers, voice recognition devices, motion or presence sensors, etc.

[0023] Manipulator assembly 102 supports medical device 104 and may include a kinematic structure of links providing a setting structure. Links may include one or more non-servo-controlled links (e.g., one or more links that can be manually positioned and locked in place) and / or one or more servo-controlled links (e.g., one or more links that can be controlled in response to commands, for example, from control system 112). Manipulator assembly 102 may include a plurality of actuators (e.g., motors) that drive inputs on medical device 104 in response to commands, for example, from control system 112. Actuators may include a drive system that moves medical device 104 in various ways when coupled to it. For example, one or more actuators may advance medical device 104 into a natural or surgically created anatomical opening. Actuators may control engagement of medical device 104, for example, by moving the distal end (or any other part) of medical device 104 in multiple degrees of freedom. These degrees of freedom may include three degrees of linear motion (e.g., linear motion along the X, Y, Z Cartesian axes) and three degrees of rotational motion (e.g., rotation about the X, Y, Z Cartesian axes). One or more actuators may control the rotation of the medical device about its longitudinal axis. Actuators may also be used to move the engageable end effector of the medical device 104 (e.g., to grasp tissue in the jaws of a biopsy device, etc.), or may be used to move or otherwise control tools inserted within the medical device 104 (e.g., imaging tools, ablation tools, biopsy tools, electroporation tools, etc.).

[0024] The medical system 100 may include a sensor system 108 having one or more subsystems for receiving information about the manipulator assembly 102 and / or the medical device 104. Such subsystems may include: a position sensor system (e.g., using an electromagnetic (EM) sensor or other type of sensor for detecting position or location); a shape sensor system for determining the position, orientation, velocity, rate, pose, and / or shape along one or more segments and / or distal ends of the flexible body of the medical device 104; a visualization system (e.g., using a color imaging device, infrared imaging device, ultrasound imaging device, X-ray imaging device, fluorescence imaging device, computed tomography (CT) imaging device, magnetic resonance imaging (MRI) imaging device, or some other type of imaging device) for capturing images, for example, from the distal end of the medical device 104 or from some other location; and / or an actuator position sensor (e.g., a resolver, encoder, potentiometer, etc.) describing the rotation and / or orientation of the actuator controlling the medical device 104.

[0025] The medical system 100 may include a display system 110 for displaying images or representations of the procedure site and the medical device 104. The display system 110 and the main component 106 may be oriented so that a physician O can use telepresent perception to control the medical device 104 and the main component 106.

[0026] In some embodiments, medical device 104 may include a visualization system that includes an image capture component that records simultaneous or real-time images of the procedure site and provides the images to an operator O via one or more displays of display system 110. The image capture component may include various types of imaging devices. The simultaneous images may be, for example, two-dimensional or three-dimensional images captured by an endoscope positioned within the anatomical procedure site. In some examples, the visualization system may include an endoscope component that may be integrally or removably coupled to medical device 104. Additionally or alternatively, a separate endoscope attached to a separate manipulator assembly may be used with medical device 104 to image the procedure site. The visualization system may be implemented as hardware, firmware, software, or a combination thereof that interacts with or is otherwise executed by one or more computer processors, such as control system 112.

[0027] Display system 110 can also display images of the process site and medical device, which can be captured by a visualization system. In some examples, medical system 100 provides operator O with a telepresented perception. For example, an image captured by an imaging device at the distal portion of medical device 104 can be presented by display system 110 to provide operator O with a perception of the distal portion of medical device 104. Inputs provided by operator O to master component 106 can move the distal portion of medical device 104 in a manner corresponding to the nature of the input (e.g., the distal end turns to the right when the trackball rolls to the right), and cause a corresponding change in the viewing angle of the image captured by the imaging device at the distal portion of medical device 104. Thus, operator O's telepresent perception is maintained when medical device 104 is moved using master component 106. Operator O can manipulate the hand controls of master component 106 and medical device 104 as if observing a workspace in a substantially realistic situation, simulating the experience of physically manipulating medical device 104 from within the patient's anatomy.

[0028] In some examples, the display system 110 may present virtual images of the procedure site created using image data recorded preoperatively (e.g., before the procedure performed by the medical device system 200) or intraoperatively (e.g., simultaneously with the procedure performed by the medical device system 200), such as image data created using computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), fluoroscopy, thermal imaging, ultrasound, optical coherence tomography (OCT), thermal imaging, impedance imaging, laser imaging, nanotube X-ray imaging, etc. The virtual images may include two-dimensional, three-dimensional, or higher-dimensional images (e.g., including information based on time or rate). In some examples, one or more models are created based on the preoperative or intraoperative image dataset, and the virtual image is generated using one or more models.

[0029] In some examples, for the purpose of image-guided medical procedures, the display system 110 can display a virtual image generated based on the position of the tracking medical device 104. For example, the tracking position of the medical device 104 can be registered with a model generated using preoperative or intraoperative images (e.g., a dynamic reference), where different parts of the model correspond to different locations of the patient's anatomy. As the medical device 104 moves through the patient's anatomy, the registration is used to determine the parts of the model corresponding to the position and / or viewpoint of the medical device 104, and a virtual image is generated using the determined parts of the model. This allows a virtual image of the internal procedure site corresponding to the tracking position of the medical device 104 to be presented to the operator O from the viewpoint of the medical device 104.

[0030] The medical system 100 may further include a control system 112, which may include processing circuitry to implement some or all of the methods or functions discussed herein. The control system 112 may include at least one memory and at least one processor for controlling the operation of the manipulator assembly 102, medical device 104, main assembly 106, sensor system 108, and / or display system 110. The control system 112 may include instructions (e.g., a non-transitory machine-readable medium storing instructions) that, when executed by at least one processor, configure one or more processors to implement some or all of the methods or functions discussed herein. Although the control system 112... Figure 1 While shown as a single block, control system 112 may include two or more separate data processing circuits, with some processing performed at manipulator component 102, others at main component 106, and so on. In some examples, control system 112 may include other types of processing circuitry systems, such as application-specific integrated circuits (ASICs) and / or field-programmable gate arrays (FPGAs). Control system 112 may be implemented using hardware, firmware, software, or a combination thereof.

[0031] In some examples, the control system 112 may receive feedback from the medical device 104, such as force and / or torque feedback. In response to this feedback, the control system 112 may transmit a signal to the main component 106. In some examples, the control system 112 may transmit a signal instructing one or more actuators of the manipulator component 102 to move the medical device 104. In some examples, the control system 112 may transmit information about the feedback to the display system 110 for presentation or to perform other types of actions based on the feedback.

[0032] Control system 112 may include a virtual visualization system to provide navigational assistance to operator O when controlling medical device 104 during image-guided medical procedures. Virtual navigation using the virtual visualization system may be based on a preoperative or intraoperative dataset of the acquired anatomical pathways of patient P. Control system 112 or a separate computing device may, alone or in combination with operator input, use programmed instructions to transform recorded images into a model of the patient's anatomy. This model may include a segmented two-dimensional or three-dimensional synthetic representation of parts or entire anatomical organs or regions. The image dataset may be associated with the synthetic representation. The virtual visualization system may obtain sensor data from sensor system 108 for calculating the (e.g., approximate) position of medical device 104 relative to the anatomical structures of patient P. Sensor system 108 may be used to register and display medical device 104 and images recorded preoperatively or intraoperatively. For example, PCT disclosure WO 2016 / 191298 (published December 1, 2016, entitled "Systems and Methods of Registration for Image Guided Surgery") discloses an example system, which is incorporated herein by reference in its entirety.

[0033] During the virtual navigation process, sensor system 108 can be used to calculate the (e.g., approximate) position of medical device 104 relative to the anatomical structure of patient P. This position can be used to generate both a macroscopic (e.g., external) tracking image of the anatomical structure of patient P and a virtual internal image of the anatomical structure of patient P. The system may include one or more electromagnetic (EM) sensors, fiber optic sensors, and / or other sensors to register and display the medical device and preoperatively recorded medical images. For example, U.S. Patent No. 8,900,131 (filed May 13, 2011, entitled “Medical System Providing Dynamic Registration of a Model of an Anatomic Structure for Image-Guided Surgery”), which is incorporated herein by reference in its entirety.

[0034] The medical system 100 may also include operating and support systems (not shown), such as lighting systems, steering and maneuvering control systems, irrigation systems, and / or suction systems. In some embodiments, the medical system 100 may include more than one manipulator assembly and / or more than one main assembly. The exact number of manipulator assemblies may depend on factors such as the medical procedure and space constraints within the operating room. Multiple main assemblies may be located in the same location or may be positioned in separate locations. Multiple main assemblies allow more than one operator to control one or more manipulator assemblies in various combinations.

[0035] Figure 2A This is a simplified diagram of a medical device system 200 according to some embodiments. The medical device system 200 includes a flexible elongation device 202 (also referred to as elongation device 202), a drive unit 204, and a medical tool 226, which together serve as an example of the medical device 104 of the medical system 100. The medical system 100 can be a remote operating system, a non-remote operating system, or a hybrid of remote and non-remote operating systems, as shown in reference... Figure 1 As described above, the visualization system 231, tracking system 230, and navigation system 232 are also included. Figure 2A The diagram shows an example component of the control system 112 of the medical system 100. In some examples, the medical device system 200 can be used in non-remotely operated exploration procedures or in procedures involving routine manual operation of medical devices (e.g., endoscopy). The medical device system 200 can be used to collect (e.g., measure) a set of data points corresponding to positions within the anatomical passage of a patient (e.g., patient P).

[0036] The elongation device 202 is coupled to the drive unit 204. The elongation device 202 includes a channel 221 through which a medical instrument 226 can be inserted. The elongation device 202 navigates within the patient's anatomy to deliver the medical instrument 226 to the procedure site. The elongation device 202 includes a flexible body 216 having a proximal end 217 and a distal end 218. In some examples, the flexible body 216 may have an outer diameter of approximately 3 mm. Other flexible bodies may have larger or smaller outer diameters.

[0037] Medical device system 200 may include a tracking system 230 for determining the position, orientation, velocity, rate, pose, and / or shape of a flexible body 216 at its distal end 218 and / or along one or more segments 224 of the flexible body 216, as will be described in further detail below. Tracking system 230 may include one or more sensors and / or imaging devices. The flexible body 216 (e.g., the length between the distal end 218 and the proximal end 217) may include multiple segments 224. Tracking system 230 may be implemented using hardware, firmware, software, or a combination thereof. In some examples, tracking system 230 is... Figure 1 Part of the control system 112 shown.

[0038] Tracking system 230 can use shape sensor 222 to track the distal end 218 and / or one or more segments 224 of flexible body 216. Shape sensor 222 may include an optical fiber aligned with flexible body 216 (e.g., disposed within an internal channel of flexible body 216 or mounted externally along flexible body 216). In some examples, the optical fiber may have a diameter of about 200 μm. In other examples, the diameter may be larger or smaller. The optical fiber of shape sensor 222 can form an optical fiber bending sensor for determining the shape of flexible body 216. Optical fibers including fiber Bragg gratings (FBGs) can be used to provide strain measurements in one or more dimensions of the structure. Various systems and methods for monitoring the shape and relative position of optical fibers in three dimensions, applicable to some embodiments, are described in U.S. Patent Application Publication No. 2006 / 0013523 (filed July 13, 2005, entitled "Fiber optic position and shape sensing device and method relating thereto"), U.S. Patent No. 7,772,541 (filed March 12, 2008, entitled "Fiber Optic Position and / or Shape Sensing Based on Rayleigh Scatter"), and U.S. Patent No. 8,773,650 (filed September 2, 2010, entitled "Optical Position and / or Shape Sensing"), all of which are incorporated herein by reference in their entirety. In some embodiments, the sensor may employ other suitable strain sensing techniques, such as Rayleigh scattering, Raman scattering, Brillouin scattering, and fluorescence scattering.

[0039] In some examples, other techniques may be used to determine the shape of the flexible body 216. For example, the history of the position and / or pose of the distal end 218 of the flexible body 216 may be used to reconstruct the shape of the flexible body 216 over time intervals, such as when the flexible body 216 advances or retracts within a patient's anatomy. In some examples, the tracking system 230 may alternatively and / or additionally use a position sensor system 220 to track the distal end 218 of the flexible body 216. The position sensor system 220 may be a component of an EM sensor system, wherein the position sensor system 220 includes one or more position sensors. Although the position sensor system 220 is shown proximate to the distal end 218 of the flexible body 216 to track the distal end 218, the number and position of the position sensors in the position sensor system 220 may vary to track different regions along the flexible body 216. In one example, the position sensors include conductive coils that can withstand externally generated electromagnetic fields. Each coil of the position sensor system 220 may generate an induced electrical signal having characteristics that depend on the position and orientation of the coil in relation to the externally generated electromagnetic field. Position sensor system 220 can measure one or more position coordinates and / or one or more orientation angles associated with one or more portions of flexible body 216. In some examples, position sensor system 220 can be configured and positioned to measure six degrees of freedom, such as three position coordinates X, Y, Z and three orientation angles indicating pitch, yaw, and roll of a reference point. In some examples, position sensor system 220 can be configured and positioned to measure five degrees of freedom, such as three position coordinates X, Y, Z and two orientation angles indicating pitch and yaw of a reference point. Further description of the position sensor system applicable to some embodiments is provided in U.S. Patent No. 6,380,732 (filed August 11, 1999, entitled "Six-Degree of Freedom Tracking System Having a Passive Transponder on the Object Being Tracked"), which is incorporated herein by reference in its entirety.

[0040] In some implementations, the tracking system 230 may alternatively and / or additionally rely on a set of pose, position, and / or orientation data stored at points on the elongation device 202 and / or medical instrument 226, captured during one or more cycles of alternating movement (e.g., breathing). This stored data can be used to develop shape information about the flexible body 216. In some examples, a series of position sensors (not shown)—such as EM sensors like those in position sensor 220 or some other type of position sensor—can be positioned along the flexible body 216 and used for shape sensing. In some examples, a history of data acquired during the procedure from one or more of these position sensors can be used to represent the shape of the elongation device 202, particularly where the anatomical passage is typically static.

[0041] Figure 2B This is a simplified diagram of a medical instrument 226 within an elongation device 202 according to some embodiments. The flexible body 216 of the elongation device 202 may include a channel 221 sized and shaped to receive the medical instrument 226. In some embodiments, the medical instrument 226 may be used for procedures such as diagnostics, imaging, surgery, biopsy, ablation, illumination, irrigation, aspiration, electroporation, etc. The medical instrument 226 can be deployed through the channel 221 of the flexible body 216 and operate at a procedure site within an anatomical structure. The medical instrument 226 may be, for example, an image capture probe, a biopsy tool (e.g., a needle, gripper, brush, etc.), an ablation tool (e.g., a laser ablation tool, a radiofrequency (RF) ablation tool, a cryoablation tool, a thermal ablation tool, a heated liquid ablation tool, etc.), an electroporation tool, and / or another surgical, diagnostic, or therapeutic tool. In some examples, the medical instrument 226 may include an end effector with a single working member, such as a scalpel, a blunt blade, an optical fiber, an electrode, etc. Other end effector types can include, for example, forceps, grippers, scissors, sutures, clamps, etc. Other end effectors can also include electrically activated end effectors, such as electrosurgical electrodes, transducers, sensors, etc.

[0042] Medical tool 226 may be a biopsy tool for removing sample tissue or cell samples from a target anatomical location. In some examples, the biopsy tool is a flexible needle. The biopsy tool may also include a sheath that can surround the flexible needle to protect the needle and the inner surface of the channel 221 when the biopsy tool is within the channel 221. Medical tool 226 may be an image capture probe that includes a distal portion having a stereo or single-field-of-view camera that can be positioned at or near the distal end 218 of the flexible body 216 for capturing images (e.g., still or video images). The captured images may be processed by visualization system 231 for display and / or provided to tracking system 230 to support tracking of the distal end 218 of the flexible body 216 and / or one or more segments 224 of the flexible body 216. The image capture probe may include a cable for transmitting the captured image data, the cable being coupled to an imaging device at the distal portion of the image capture probe. In some examples, the image capture probe may include a bundle of optical fibers, such as a fiber optic endoscope, coupled to a closer imaging device, such as the visualization system 231. The image capture probe may be monospectral or multispectral, capturing image data in one or more of the visible, near-infrared, infrared, and / or ultraviolet spectra. The image capture probe may also include one or more light emitters that provide illumination to facilitate image capture. In some examples, the image capture probe may use ultrasound, X-ray, fluoroscopy, CT, MRI, or other types of imaging techniques.

[0043] In some examples, an image capture probe is inserted within the flexible body 216 of the elongation device 202 to facilitate visual navigation of the elongation device 202 to the procedure site, and then the image capture probe is replaced within the flexible body 216 with another type of medical instrument 226 for performing the procedure. In some examples, the image capture probe may be located together with another type of medical instrument 226 within the flexible body 216 of the elongation device 202 to facilitate simultaneous image capture and tissue intervention, for example, within the same channel 221 or in different channels. The medical instrument 226 may advance from an opening in the channel 221 to perform the procedure (or some other function) and then retract into the channel 221 upon completion of the procedure. The medical instrument 226 may be removed from the proximal end 217 of the flexible body 216 or along the flexible body 216 from another optional instrument port (not shown).

[0044] In some examples, the extension device 202 may include integrated imaging capabilities instead of utilizing a removable image capture probe. For example, the imaging device (or fiber bundle) and light emitter may be located at the distal end 218 of the extension device 202. The flexible body 216 may include one or more dedicated channels carrying cables and / or optical fibers between the distal end 218 and the visualization system 231. Here, the medical device system 200 can perform imaging and tooling operations simultaneously.

[0045] In some examples, the medical tool 226 is capable of controlled engagement. The medical tool 226 may house a cable (also referred to as a traction cable), linkage, or other actuation controls (not shown), extending between its proximal and distal ends to controllably bend the distal end of the medical tool 226, such as those discussed herein with respect to the flexible elongation device 202. The medical tool 226 may be coupled to the drive unit 204 and the manipulator assembly 102. In these examples, the elongation device 202 may be excluded from the medical device system 200, or may be a flexible device without controlled engagement. Steering maneuvers or instruments applicable to some embodiments are further described in detail in U.S. Patent No. 7,316,681 (filed October 4, 2005, entitled "Articulated Surgical Instrument for Performing Minimally Invasive Surgery with Enhanced Dexterity and Sensitivity") and U.S. Patent No. 9,259,274 (filed September 30, 2008, entitled "Passive Preload and Capstan Drive for Surgical Instruments"), which are incorporated herein by reference in their entirety.

[0046] The flexible body 216 of the elongation device 202 may also, or alternatively, accommodate a cable, linkage, or other steering control (not shown) extending between the drive unit 204 and the distal end 218 to controllably bend the distal end 218, such as by, for example, a cable, linkage, or other steering control. Figure 2A The distal end 218 is depicted by a dashed line 219. In some examples, at least four cables are used to provide independent up-and-down steering maneuvers to control the pitch of the distal end 218 and left-and-right steering maneuvers to control the yaw of the distal end 218. In these examples, the flexible elongation device 202 may be a steerable maneuverable conduit. Examples of steerable maneuverable conduits suitable for some embodiments are described in detail in PCT Publication WO 2019 / 018736 (published January 24, 2019, entitled "Flexible Elongate Device Systems and Methods"), which is incorporated herein by reference in its entirety.

[0047] In embodiments where the elongation device 202 and / or medical tool 226 is actuated by a remotely operated component (e.g., manipulator component 102), the drive unit 204 may include a drive input removably coupled to and receiving power from a drive element (e.g., an actuator) of the remotely operated component. In some examples, the elongation device 202 and / or medical tool 226 may include a grasping feature, a manual actuator, or other components for manually controlling the movement of the elongation device 202 and / or medical tool 226. The elongation device 202 may be steerable, or alternatively, it may be non-steerable, without an integrated mechanism for operator control of bending of the distal end 218. In some examples, one or more channels 221 (which may also be referred to as lumens) may be defined by the inner wall of the flexible body 216 of the elongation device 202, through which the medical tool 226 may be deployed and used at a target anatomical location.

[0048] In some examples, medical device system 200 (e.g., extension device 202 or medical tool 226) may include flexible bronchial instruments, such as bronchoscopes or bronchial tubes, for the examination, diagnosis, biopsy, and / or treatment of the lungs. Medical device system 200 may also be adapted to navigate and treat other tissues within any anatomical system of a variety of anatomical systems via naturally or surgically generated access channels, including the colon, intestine, kidneys and renal calyces, brain, heart, circulatory system including the vascular system, etc.

[0049] Information from tracking system 230 can be sent to navigation system 232, where it can be combined with information from visualization system 231 and / or a preoperatively acquired model to provide real-time location information to physicians, clinicians, surgeons, or other operators. In some examples, the real-time location information can be displayed on display system 110 for controlling medical device system 200. In some examples, navigation system 232 can utilize the location information as feedback for locating medical device system 200. Various systems for registering and displaying surgical instruments and surgical images using fiber optic sensors, applicable to some embodiments, are provided in U.S. Patent No. 8,900,131 (filed May 13, 2011, entitled “Medical System Providing Dynamic Registration of a Model of an Anatomic Structure for Image-Guided Surgery”), which is incorporated herein by reference in its entirety.

[0050] Figure 3A and Figure 3BThis is a simplified side view of a medical device mounted on an insertion assembly, according to some embodiments, in patient coordinate space. Figure 3A and 3B As shown, the surgical environment 300 may include a patient P positioned on a patient table T. Patient P may be stationary within the surgical environment 300 because overall patient movement is restricted by sedation, restraint, and / or other means. Periodic anatomical movements of patient P (including respiratory and cardiac movements) may continue. Within the surgical environment 300, a medical device 304 is used to perform medical procedures, which may include, for example, surgery, biopsy, ablation, illumination, irrigation, aspiration, or electroporation. The medical device 304 may also be used to perform other types of procedures, such as a registration process that associates position, orientation, and / or pose data captured by a sensor system 108 with a desired (e.g., anatomical or systemic) reference frame. The medical device 304 may be, for example, medical device 104. In some examples, the medical device 304 may include an elongation device 310 (e.g., a catheter) coupled to an instrument body 312. The elongation device 310 includes one or more channels sized and shaped to receive medical instruments.

[0051] The elongation device 310 may also include one or more sensors (e.g., components of sensor system 108). In some examples, a shape sensor 314 may be fixed at a proximal point 316 on the instrument body 312. The proximal point 316 of the shape sensor 314 may move with the instrument body 312, and the position of the proximal point 316 relative to a desired reference frame may be known (e.g., via a tracking sensor or other tracking device). The shape sensor 314 may measure the shape from the proximal point 316 to another point (e.g., the distal end 318 of the elongation device 310). The shape sensor 314 may be aligned with the elongation device 310 (e.g., disposed within an internal channel or mounted externally). In some examples, the shape sensor 314 may be an optical fiber used to generate shape information of the elongation device 310.

[0052] In some examples, position sensors (e.g., EM sensors) may be incorporated into medical device 304. A series of position sensors may be positioned along the flexible elongation device 310 and used for shape sensing. Position sensors may be used in place of or in conjunction with shape sensor 314, for example, to improve the accuracy of shape sensing or to verify shape information.

[0053] The extension device 310 may accommodate cables, linkages, or other steering control mechanisms that extend between the instrument body 312 and the distal end 318 to controllably bend the distal end 318. In some examples, at least four cables are used to provide independent up-and-down steering control to control the pitch of the distal end 318 and left-and-right steering control to control the yaw of the distal end 318. The instrument body 312 may include a drive input that is removably coupled to and receives power from a drive element (e.g., an actuator) of the manipulator assembly.

[0054] The instrument body 312 may be coupled to the instrument holder 306. The instrument holder 306 may be mounted to an insertion stage 308 fixed within the surgical environment 300. Alternatively, the insertion stage 308 may be movable but has a known position within the surgical environment 300 (e.g., via a tracking sensor or other tracking device). The instrument holder 306 may be a component of a manipulator assembly (e.g., manipulator assembly 102) coupled to the medical device 304 to control insertion motion (e.g., movement along insertion axis A) and / or movement of the distal end 318 of the elongation device 310 in multiple directions, such as yaw, pitch, and / or roll. The instrument holder 306 or the insertion stage 308 may include actuators, such as servo motors, for controlling the movement of the instrument holder 306 along the insertion stage 308.

[0055] Sensor device 320 (which may be a component of sensor system 108) can provide information about the position of instrument body 312 as it moves along insertion axis A relative to insertion stage 308. Sensor device 320 may include one or more rotary transformers, encoders, potentiometers, and / or other sensors that measure the rotation and / or orientation of actuators controlling the movement of instrument carrier 306, thereby indicating the movement of instrument body 312. In some embodiments, insertion stage 308 has, for example, […]. Figure 3A and Figure 3B The linear track is shown. In some embodiments, the insertion stage 308 may have a curved track or a combination of curved track segments and linear track segments.

[0056] Figure 3A The instrument body 312 and instrument holder 306 are shown in the retracted position along the insertion stage 308. In this retracted position, the proximal point 316 is located at position L0 on the insertion axis A. The position of the proximal point 316 can be set to zero and / or other reference values ​​to provide a basic reference (e.g., corresponding to the origin of the desired reference system) to describe the position of the instrument holder 306 along the insertion stage 308. In the retracted position, the distal end 318 of the extension device 310 can be positioned precisely within the inlet orifice of the patient P. Also in the retracted position, data captured by the sensor device 320 can be set to zero and / or other reference values ​​(e.g., I=0). Figure 3BIn this configuration, the instrument body 312 and instrument holder 306 have advanced along the linear track of the insertion stage 308, and the distal end 318 of the elongation device 310 has advanced into the patient P. At this advanced position, the proximal point 316 is at position L1 on the insertion axis A. In some examples, rotation and / or orientation of the actuator measured by the sensor device 320 indicating the movement of the instrument holder 306 along the insertion stage 308 and / or by one or more position sensors associated with the instrument holder 306 and / or the insertion stage 308 can be used to determine the position L1 of the proximal point 316 relative to position L0. In some examples, position L1 can also serve as an indicator of the distance or insertion depth of the distal end 318 of the elongation device 310 inserted into the channel of the anatomical structure of the patient P.

[0057] Figure 4 This is a simplified diagram of a medical system 400 including a flexible elongation device 402. According to... Figure 1 In some embodiments consistent with Figure 3, medical device system 400 may correspond to medical device system 200, and / or flexible elongation device 402 may correspond to elongation device 202.

[0058] The flexible elongation device 402 has a flexible body that may include a lumen 404 extending through the flexible body. The lumen 404 may provide a delivery channel for medical instruments to be inserted into the flexible body through the flexible elongation device 402, such as visual probes, biopsy tools (e.g., needles, brushes, cryoprobes, or forceps), ablation tools, electroporation tools, ultrasound devices (e.g., endobronchial ultrasound (EBUS) probes), chemical delivery tools, etc.

[0059] As shown, the flexible elongation device 402 includes an engageable body portion 406 and a pair of traction wires 408a, 408b within the engageable body portion 406. One or more actuators 410 are coupled to the pair of traction wires 408a, 408b and configured to control engagement of the engageable body portion 406 along an axis (e.g., pitch or yaw). Although a pair of traction wires is shown, the flexible elongation device 402 may include one or more additional pairs of traction wires having a similar configuration and control as described herein, such that the flexible elongation device 402 can be engageable along multiple axes. In the illustrated example, the body includes a proximal portion 412 and a distal portion 414, wherein the distal portion 414 includes the engageable body portion 406. The pair of traction wires 408a, 408b may extend along the entire length of the body to couple to an actuator 410 adjacent to the proximal portion 412 of the flexible elongation device 402.

[0060] The medical system 400 also includes a control system 416 operatively coupled to the actuator 410 to control its operation, thereby controlling the engagement of the engageable body portion 406. In this configuration, a user can use the control system 416 to manipulate the flexible elongation device 402 through the patient's anatomy, causing the body of the flexible elongation device 402 to bend along its length.

[0061] like Figure 4 As shown, the flexible elongation device 402 may also include one or more sensors coupled to or associated with it to provide data on the control, state, position, orientation, speed, rate, pose, and / or shape of the flexible elongation device 402. For example, the flexible elongation device 402 may include a shape sensor 420 (e.g., a fiber optic shape sensor) extending along its length, which provides data on the shape and position of the flexible elongation device 402, including its engageable body portion 406 (e.g., position and / or bending angle). In additional or alternative examples, the flexible elongation device 402 may include one or more position sensors 422 (e.g., electromagnetic sensors) and / or one or more imaging sensors 424 (e.g., camera, ultrasound, fluorescence microscope, etc.). Although in Figure 4 The image is shown as separate from the flexible elongation device 402, but the position sensor 422 and / or imaging sensor 424 may be integrated with the flexible elongation device 402 or a tool inserted through the lumen 404 of the flexible elongation device 402. In some embodiments, the shape sensor 420 may additionally or alternatively be located in the tool inserted through the lumen 404 of the flexible elongation device 402.

[0062] System 400 may also include one or more sensors associated with actuator 410 to provide data about its operation. For example, system 400 may include one or more actuator position sensors 426, such as resolvers, encoders, potentiometers, etc., describing the rotation and / or orientation of actuator 410.

[0063] System 400 may also include one or more sensors configured to provide data on the tension of traction lines 408a, 408b. In one example, system 400 includes one or more current sensors 428 configured to measure the current through the motor of actuator 410. In this example, system 400 can be implemented without directly measuring the tension of the traction lines using torque sensors. In another example, system 400 includes one or more torque sensors 430 coupled to the output of the gearbox of actuator 410 and / or coupled to one or both of the traction lines 408a, 408b. Sensors 428, 430 enable control system 416 to track the tension in traction lines 408a, 408b.

[0064] According to some embodiments, the control system 416 can be configured to determine the bending parameters of the flexible elongation device 402 based on sensor data. The bending parameters are a measure or value dependent on the curvature of the flexible elongation device 402 and are therefore related to the amount of slack in the traction lines of the flexible elongation device 402. The bending parameters can provide an indication of the severity and / or cumulative nature of the bending of the flexible elongation device 402 due to manipulation within the patient's anatomy, providing information about potential friction within the flexible elongation device 402 and the resulting slack in the traction lines 408a, 408b extending through it.

[0065] The bending parameters can include any desired number of inputs. In some examples, the bending parameters can include: the overall or partial shape of the flexible elongation device 402 provided by data from the shape sensor 420; the cumulative curvature along a portion (e.g., some or all, distal, intermediate, and / or proximal portions) or the entire length of the flexible elongation device 402 based on data from the shape sensor 420, position sensor 422, and / or imaging sensor 424; the cumulative bending angle of the engageable body portion 406 of the flexible elongation device 402 based on data from the shape sensor 420, position sensor 422, and / or imaging sensor 424; the insertion depth of the flexible elongation device 402 into the patient's anatomy based on data from the shape sensor 420, position sensor 422, imaging sensor 424, and / or system-side sensors (e.g., sensors or optical sensors coupled to a drive mechanism or structure that moves the flexible elongation device 402 forward); and / or an anatomical model of the patient's anatomy, which can include a desired path within the patient's anatomy for a particular procedure.

[0066] Each of the above inputs is intended to determine the number and / or severity of bends in the flexible elongation device 402 at a given point during the process (e.g., deviation of a portion of the flexible elongation device from linear orientation). For example, a larger number of bends and / or a smaller bend radius (e.g., for any bend) may be associated with a larger bend parameter, while a smaller number of bends and / or a larger bend radius may be associated with a smaller bend parameter. Here, a larger bend parameter is associated with a larger amount of relaxation. In one example, the bend parameter may be based on a count of the number of bends in the flexible elongation device 402, dynamically based on data from the shape sensor 420 or based on a cumulative count of the number of times the engageable body portion 406 is manipulated during the process (based on data from the shape sensor 420, position sensor 422, and / or imaging sensor 424). In additional or alternative examples, the bend parameter may be based on an estimated count of the number of bends in the flexible elongation device 402. The estimate may be based on: the insertion depth of the flexible elongation device 402 in the patient's body, wherein it is assumed that the deeper the flexible elongation device 402 is inserted into the patient's body, the more bending and / or the greater the severity of bending will accumulate; and / or an anatomical model of the patient's anatomy, which may be based on the expected path through the patient's anatomy to determine the total number of bending and / or the severity of bending that will be applied to the flexible elongation device 402 during the procedure.

[0067] In additional or alternative examples, the bending parameters can be the difference between the expected parameters (e.g., position, bending radius, and / or bending angle) of the engageable body portion 406 of the flexible elongation device 402 (e.g., determined by predictive modeling) and the actual parameters (e.g., position, bending radius, and / or bending angle) of the engageable body portion 406 of the flexible elongation device 402 (e.g., measured by one or more sensors). The amount of difference between the predicted and actual parameters may be due to slack.

[0068] In one embodiment, system 400 includes an actuator position sensor 426. Based on data from the actuator position sensor 426 (e.g., encoder data), expected parameters of the engageable body portion 406 of the flexible elongation device 402 can be determined based on modeling of system 400, wherein the operation of actuator 410 is related to the movement of the engageable body portion 406. In the event of slack in one or both of the traction lines 408a, 408b, the actual parameters of the engageable body portion 406 will differ from the expected parameters because: since slack does not apply the full input of actuator 410 to the engageable body portion 406. To obtain the actual parameters of the engageable body portion 406, system 400 may use a shape sensor 420 and / or a position sensor 422.

[0069] For a system that uses the estimated and actual locations to at least partially determine the bending parameters, the difference threshold can be between about 3 mm and about 5 mm, or between about 3 mm and about 10 mm.

[0070] For a system that uses the estimated bending angle and the actual bending angle to at least partially determine the bending parameters, the difference threshold can be between about 30 degrees and about 90 degrees, between about 40 degrees and about 80 degrees, between about 50 degrees and about 70 degrees, or about 60 degrees.

[0071] For a system that uses the estimated bending radius and the actual bending radius to at least partially determine the bending parameters, the difference threshold can be between about 5 mm and about 8 mm, or between about 5 mm and about 15 mm.

[0072] Control system 416 operates actuator 410 to maintain minimum tension in the paired traction lines 408a, 408b. For a pair of opposing traction lines 408a, 408b controlling engagement of a single shaft, minimum tension refers to the lowest permissible tension of traction line 408a or traction line 408b. For example, minimum tension may correspond to the tension applied to the passive traction line 408a, 408b during engagement changes of the engageable body portion 406 caused by tension changes applied to the active traction line in the paired traction lines 408a, 408b. Here, the active traction line has an increased tension above the minimum tension to control engagement, while the passive traction line remains at the minimum tension. Minimum tension can be dynamically adjusted to ensure that the tension applied to traction lines 408a, 408b does not drop below a minimum threshold required or anticipated by system 400. Tension changes applied to the active traction lines 408a, 408b for engagement movement may include increases or decreases in tension maintained above or equal to the minimum tension.

[0073] In some examples, system 400 may use the lowest possible minimum tension and / or the highest possible minimum tension as limits for a dynamically adjustable minimum tension. These values ​​may be included to ensure proper operation of system 400 and / or the expected lifespan of system 400's components. In these examples, control system 416 will stop decreasing the minimum tension when the lowest possible minimum tension is reached, and will stop increasing the minimum tension when the highest possible minimum tension is reached.

[0074] In some embodiments, the control system 416 determines the bending parameters of the flexible elongation device 402 during the process and adjusts the minimum tension in the traction lines 408a, 408b accordingly based on the bending parameters. Adjustment of the minimum tension may include increasing and / or decreasing the minimum tension. In some examples, the control system 416 may be configured to reduce the minimum tension (e.g., by a predetermined amount or to the lowest possible minimum tension) after reaching the desired position within the patient's body for a particular process, such that no further manipulation of the engageable body portion 406 is intended. The control system 416 may determine the desired position by any suitable method, including, for example, a mode change of system 400, placement of the drive mechanism for the flexible elongation device 402, or based on data from position / shape sensors, etc.

[0075] In an attempt to overcome friction in the flexible elongation device 402 and eliminate slack in the traction wires 408a, 408b, the control system 416 may determine a new minimum tension (e.g., a minimum tension increased relative to a previous minimum tension) for the paired traction wires 408a, 408b based on bending parameters. This determination may also include an intermediate step of determining slack in one or both of the traction wires 408a, 408b based on the bending parameters, and subsequently determining the minimum tension required to eliminate the slack. Thereafter, the control system 416 controls the operation of the actuator 410 based on the determination of the minimum tension for the traction wires 408a, 408b.

[0076] The determination of the new minimum tension can follow any number of suitable decision paths. For example, the determination could correspond to a pre-defined increase in the minimum tension in response to a bending parameter exceeding a predetermined threshold. In another example, the bending parameter could have multiple or a series of increasing thresholds (e.g., stepwise changes) with corresponding series of increasing minimum tension values. In yet another example, the bending parameter could have values ​​set along a scale (e.g., linearly or some other relationship), and the minimum tension would increase proportionally accordingly.

[0077] In some examples, the control system 416 establishes a new minimum tension and waits for further data to determine if an additional increase in the minimum tension is needed. In other examples, the control system 416 increases the minimum tension until the control system determines that slack has been eliminated from the traction lines 408a, 408b.

[0078] The determination of slack elimination from traction lines 408a and 408b can be performed in a variety of suitable ways. In one example, control system 416 performs a comparison between the expected parameters and the parameters of the engageable body portion 406 to determine the bending parameters, as discussed in more detail above. Through this comparison, control system 416 can monitor the difference between the expected and actual parameters of the engageable body portion 406 as the minimum tension increases, and stop increasing the minimum tension in response to the difference decreasing below a predetermined threshold.

[0079] In other examples, the control system 416 may monitor the movement of the flexible elongation device 402 and use the smoothness of the movement as an indicator of when slack is eliminated from the traction lines 408a, 408b. Elimination of slack (e.g., uneven movement) can be identified by oscillations in the engageable body portion 406, one or more sudden jumps shown in the position data of the engageable body portion 406, etc. In these examples, upon identifying data indicating slack elimination, the control system 416 stops increasing the minimum tension.

[0080] In some implementations, the control system 416 determines the bending parameters of the flexible elongation device 402 during the process and detects slack in the traction lines 408a, 408b based on the bending parameters. The control system 416 then determines a minimum tension in response to the slack. Determining the minimum tension may include increasing the minimum tension. In some examples, the control system 416 may determine the minimum tension based on the bending parameters used to detect slack in the traction lines 408a, 408b or based on a second bending parameter different from the bending parameters used to detect slack in the traction lines 408a, 408b. For example, the first bending parameter may be based on one or more of the above inputs, and the second bending parameter may be based on one or more different inputs or different combinations of inputs.

[0081] As discussed above, the flexible elongation device 402 includes a lumen 404 providing a delivery channel for a medical tool 432, such as a visual probe, biopsy tool (e.g., needle, brush, cryoprobe, or forceps), ablation tool, electroporation tool, ultrasound device (e.g., endobronchial ultrasound (EBUS) probe), chemical delivery tool, etc. The characteristics of the tool 432 can affect the characteristics and shape of the flexible elongation device 402, and thus can alter the friction within the flexible elongation device 402. Therefore, in another embodiment, the control system 416 is configured to adjust bending parameters based on the tool 432 inserted or to be inserted into the lumen 404 for a particular process. For example, the presence of the tool may lead to increased friction and relaxation, resulting in a higher minimum tension. The identification of the tool 432 may be by user input to the system 400 and / or may be based on sensor identification (e.g., an inductive sensor that provides inductance data along the length of the tool 432 to match inductance data of a known tool type). In some examples, the characteristics of the tool or the effects caused by those characteristics (e.g., stiffness, friction, etc.) can be used to adjust the minimum tension.

[0082] Figure 5 A method 500 for determining the minimum tension for a medical system including a flexible elongation device (e.g., medical system 400 and flexible elongation device 402) is shown according to some embodiments. Method 500 is shown as a set of operations or processes 502 to 514. Not all processes shown are performed in all embodiments of method 500. Additionally, Figure 6 One or more processes not explicitly shown may be included before, after, between, or as part of processes 502 to 514. Processes may also be executed in different orders. In some embodiments, one or more of processes 502 to 514 may be implemented at least partially in the form of executable code stored on a non-transitory tangible machine-readable medium, which, when run by one or more processors (e.g., the processor of a controller), causes one or more processors to execute one or more processes. In one or more embodiments, processes 502 to 514 may be executed by a controller (e.g., control system 416).

[0083] In process 502, the control system (e.g., control system 416) determines the bending parameters of the paired traction lines (e.g., traction lines 408a, 408b) of the flexible elongation device (e.g., flexible elongation device 402) based on data from one or more sensors (e.g., sensors 420, 422, 424, 426). In process 504, the bending parameters can be adjusted based on a tool (e.g., tool 432) that can be inserted into the lumen of the flexible elongation device (e.g., lumen 404). In process 506, slack in the paired traction lines is determined based on the bending parameters.

[0084] In process 508, a minimum tension for the paired traction lines is determined based on the bending parameters. In some examples, determining the minimum tension in process 508 may include: determining a minimum tension sufficient to eliminate slack; providing an increased minimum tension to eliminate slack in response to determining that the bending parameters are greater than a predetermined threshold; and / or providing an increased minimum tension to eliminate slack based on the smoothness of motion of the flexible elongation device. In process 510, the control system may stop increasing the minimum tension in response to reaching a predetermined maximum amount of the minimum tension. In process 512, the control system uses the minimum tension to control one or more actuators (e.g., actuator 410) coupled to the paired traction lines to control the engagement of the engageable body portion (e.g., engageable body portion 406) of the flexible elongation device along the axis. In process 514, the control system reduces the minimum tension.

[0085] In some examples, process 514 may include: reducing minimum tension after reaching the desired location within the patient body (e.g., at the target location or at another location where further engagement of the engagement body portion is not expected); reducing minimum tension in response to a decrease in bending parameters (e.g., due to partial retraction of the flexible elongation device, repositioning, patient movement or other movement; due to increased combined stiffness of the tool and flexible elongation device due to tool insertion, etc.); and / or reducing minimum tension when the flexible elongation device is retracted at the end of the process.

[0086] Figure 6 A method 600 for determining the minimum tension for a medical system including a flexible elongation device (e.g., medical system 400 and flexible elongation device 402) is shown according to some embodiments. Method 600 is shown as a set of operations or processes 602 to 618. Not all of the processes shown are performed in all embodiments of method 600. Additionally, Figure 6One or more processes not explicitly shown may be included before, after, between, or as part of processes 602 to 618. Processes may also be executed in different orders. In some embodiments, one or more of processes 602 to 618 may be implemented at least partially in the form of executable code stored on a non-transitory tangible machine-readable medium, which, when run by one or more processors (e.g., the processor of a controller), causes one or more processors to execute one or more processes. In one or more embodiments, processes 602 to 618 may be executed by a controller (e.g., control system 416).

[0087] In process 602, the control system (e.g., control system 416) determines measurement parameters of the engageable body portion (e.g., engageable body portion 406) of the flexible elongation device (e.g., flexible elongation device 402) based on data from one or more sensors (e.g., sensors 420, 422, 424, 426). In process 604, the control system determines estimated parameters of the engageable body portion of the flexible elongation device based on the state of one or more actuators (e.g., actuator 410) coupled to a pair of traction lines (e.g., traction lines 408a, 408b) of the flexible elongation device. In some examples, the measurement parameters may be the measured position, bending angle, and / or bending radius of the engageable body portion, and the estimated parameters may be the estimated position, bending angle, and / or bending radius of the engageable body portion.

[0088] In process 606, the control system identifies slack in at least one of the paired traction lines based on a comparison of measured and estimated parameters. In process 608, the control system determines bending parameters of the flexible elongation device based on data from one or more sensors (e.g., sensors 420, 422, 424, 426). In process 610, the control system determines the minimum tension for the paired traction lines based on the bending parameters. In process 612, the control system adjusts the minimum tension for the paired traction lines in response to identifying slack. In process 614, the control system increases the minimum tension until the difference between the measured and estimated parameters falls below a predetermined threshold, or until a predetermined maximum amount of minimum tension is reached. In process 616, the control system adjusts the predetermined threshold based on a tool (e.g., tool 432) that can be inserted into a lumen (e.g., lumen 404) of the flexible elongation device. In process 618, the control system decreases the minimum tension.

[0089] In some examples, the process 618 may include: reducing minimum tension after reaching the desired location within the patient body (e.g., at the target location or at another location where further engagement of the host body is not expected); and / or reducing minimum tension based on estimated parameters and measured parameters (e.g., the difference between the estimated parameters and the measured parameters is zero or below a predetermined threshold, or in response to the consistency of the estimated parameters and the measured parameters).

[0090] One or more components of the embodiments discussed in this disclosure (e.g., control systems 112, 416) can be implemented in software to execute on one or more processors of a computer system. The software may include code that, when executed by one or more processors, configures the processors to perform the various functions discussed herein. The code may be stored in a non-transitory computer-readable storage medium (e.g., memory, magnetic storage device, optical storage device, solid-state storage device, etc.). The computer-readable storage medium may be part of a computer-readable storage device, such as electronic circuitry, a semiconductor device, a semiconductor memory device, a read-only memory (ROM), flash memory, an erasable programmable read-only memory (EPROM), a floppy disk, a CD-ROM, an optical disk, a hard disk, or other storage device. The code may be downloaded to the computer-readable storage medium for storage via a computer network such as the Internet, an intranet, etc. The code may be executed by any of a variety of centralized or distributed data processing architectures. The programming instructions of the code may be implemented as multiple separate programs or subroutines, or they may be integrated into multiple other aspects of the system described herein. The components of the computing system discussed herein may be connected using wired and / or wireless connections. In some examples, wireless connectivity can use wireless communication protocols such as Bluetooth, Near Field Communication (NFC), Infrared Data Association (IrDA), Home RF, IEEE 802.11, Digital Enhanced Cordless Telecommunications (DECT), and Wireless Medical Telemetry Service (WMTS).

[0091] Various general-purpose computer systems can be used to perform one or more processes, methods, or functions described herein. Additionally or alternatively, various special-purpose computer systems can be used to perform one or more processes, methods, or functions described herein. Furthermore, various programming languages ​​can be used to implement one or more processes, methods, or functions described herein.

[0092] While certain implementations and examples have been described above and shown in the accompanying drawings, it should be understood that these implementations and examples are merely exemplary and not limited to the specific constructions and arrangements shown and described, as various other alternatives, modifications and equivalents will be understood by those skilled in the art.

Claims

1. A medical system comprising: A flexible elongation device, the flexible elongation device including a pair of traction lines configured to control the engagement of the flexible elongation device along an axis. An actuator coupled to the pair of traction lines and configured to apply tension to the pair of traction lines; as well as The control system is configured to: The bending parameters of the flexible elongation device are determined based on data from one or more sensors; as well as The minimum tension applied to the paired traction lines by the actuator is adjusted based on the bending parameters.

2. The medical system according to claim 1, wherein, The bending parameters include the shape of at least a portion of the flexible elongation device.

3. The medical system according to claim 1, wherein, The bending parameters include the cumulative curvature along at least a portion of the flexible elongation device.

4. The medical system according to claim 1, wherein, The bending parameter includes at least one of the following: the cumulative bending angle along at least a portion of the flexible elongation device; or the radius of curvature along at least a portion of the flexible elongation device.

5. The medical system according to claim 1, wherein, The bending parameters are based on one or more of the following: the insertion depth of the flexible elongation device; or an anatomical model of the patient's anatomy.

6. The medical system according to claim 1, wherein: The flexible elongation device includes an engageable body portion, and the paired traction lines are configured to control the engagement of the engageable body portion; and The bending parameters include the difference between the expected parameters and the measured parameters of the joinable body portion.

7. The medical system according to claim 6, wherein, The expected parameter is the expected bending angle, and the measured parameter is the measured bending angle.

8. The medical system according to claim 6, wherein, The expected parameter is the expected location, and the measured parameter is the measured location.

9. The medical system according to claim 6, wherein, The expected parameter is the expected bending radius, and the measured parameter is the measured bending radius.

10. The medical system of claim 6, further comprising one or more actuator encoders coupled to the actuator; and wherein, The flexible elongation device includes a shape sensor, the expected parameters are determined using the one or more actuator encoders, and the measured parameters are determined using the shape sensor.

11. The medical system according to claim 6, wherein, The control system is also configured to: Based on the bending parameters, slack in the paired traction lines is identified; and The slack in the paired traction lines is eliminated by increasing the minimum tension until the difference between the expected parameter and the measured parameter of the engageable body portion decreases below a predetermined threshold.

12. The medical system according to claim 1, wherein, The control system configured to adjust the minimum tension applied by the actuator to the paired traction lines based on the bending parameters includes a control system configured to perform the following operations: Based on the bending parameters, slack in the paired traction lines is identified; as well as The minimum tension is determined in response to the relaxation.

13. The medical system according to claim 12, wherein, The control system is configured to determine the minimum tension based on a second bending parameter that is different from the bending parameter.

14. The medical system according to claim 12, wherein, The control system is configured to eliminate slack by: The minimum tension is increased based on the smoothness of the movement of the flexible elongation device until the slack is eliminated; Increase the minimum tension by a series of stepwise changes; or The minimum tension is increased in a linear transition.

15. The medical system according to any one of claims 1 to 14, wherein, The control system is configured to reduce or increase the minimum tension based on the bending parameters.

16. The medical system according to any one of claims 1 to 14, wherein, The system does not include any torque sensors configured to directly measure the tension in the paired traction lines.

17. The medical system according to any one of claims 1 to 14, wherein, The flexible elongation device includes a lumen extending therethrough for receiving one or more tools; and the control system is configured to determine the minimum tension based on the tools that can be inserted into the lumen.

18. A medical system comprising: The flexible elongation device includes: Connectable main body parts; and A pair of traction lines, the pair of traction lines being configured to control the engagement of the engageable body portion along an axis; One or more sensors associated with the flexible elongation device; An actuator, coupled to the pair of traction wires and configured to apply tension to the pair of traction wires; and The control system is configured to: Measurement parameters of the engageable body portion are determined based on data from one or more sensors; The estimated parameters of the engageable body portion are determined based on the state of the one or more actuators; Based on a comparison of the measured parameters and the estimated parameters, slack in at least one of the paired traction lines is identified; and In response to recognizing the slack, the minimum tension for the paired traction lines is adjusted.

19. The medical system according to claim 18, wherein, The measurement parameter is the measured bending angle, and the estimation parameter is the estimated bending angle.

20. The medical system according to claim 18, wherein, The measurement parameter is the measurement location, and the estimated parameter is the expected location.

21. The medical system according to claim 18, wherein, The measurement parameter is the measured bending radius, and the estimated parameter is the expected bending radius.

22. The medical system according to any one of claims 18 to 21, further comprising one or more actuator encoders coupled to said actuator; and wherein, The one or more sensors include a shape sensor for the flexible elongation device, the expected parameters are determined using the one or more actuator encoders, and the measurement parameters are determined using the shape sensor.

23. The medical system according to any one of claims 18 to 21, wherein, The control system is configured to increase the minimum tension until the difference between the measured parameter and the estimated parameter decreases below a predetermined threshold.

24. The medical system according to claim 23, wherein, The predetermined threshold is 60 degrees.

25. The medical system according to any one of claims 18 to 21, wherein, The medical system does not include a torque sensor configured to directly measure the tension of the paired traction wires.

26. The medical system according to any one of claims 18 to 21, wherein, The control system is configured to: The bending parameters of the flexible elongation device are determined based on data from one or more of the sensors. as well as The minimum tension applied to the paired traction lines by the actuator is adjusted based on the bending parameters.

27. The medical system according to claim 26, wherein, The bending parameters include the shape of at least a portion of the flexible elongation device.

28. The medical system according to claim 26, wherein, The bending parameters include: the cumulative curvature along at least a portion of the flexible elongation device; or the cumulative bending angle along at least a portion of the flexible elongation device.

29. The medical system according to claim 26, wherein, The bending parameter includes at least one of the following: the cumulative bending angle along at least a portion of the flexible elongation device; or the radius of curvature along at least a portion of the flexible elongation device.

30. The medical system according to claim 26, wherein, The bending parameters are based on one or more of the following: the insertion depth of the flexible elongation device; or an anatomical model of the patient's anatomy.

31. The medical system according to claim 26, wherein, The control system is configured to reduce or increase the minimum tension based on the bending parameters.

32. The medical system according to claim 26, wherein, The control system configured to adjust the minimum tension applied by the actuator to the paired traction lines based on the bending parameters includes a control system configured to perform the following operations: Based on the bending parameters, slack in the paired traction lines is identified; as well as The minimum tension is determined in response to the relaxation.

33. The medical system according to claim 32, wherein, The control system is configured to determine the minimum tension based on a second bending parameter that is different from the bending parameter.

34. The medical system according to any one of claims 18 to 21, wherein, The flexible elongation device includes a lumen extending through the flexible elongation device to receive one or more tools, and the control system is configured to determine the minimum threshold based on the tools that can be inserted into the lumen.

35. A non-transitory computer-readable medium having instructions stored thereon, the instructions causing the computing device, when executed by a computing device, to: The bending parameters of the flexible elongation device are determined based on data from one or more sensors; and The minimum tension applied to the paired traction lines by an actuator coupled to the paired traction lines is adjusted based on the bending parameters, and the paired traction lines are configured to control the engagement of the flexible elongation device.

36. The non-transitory computer-readable medium according to claim 35, wherein, The bending parameters include or are based on one or more of the following: the shape of at least a portion of the flexible elongation device; the cumulative curvature along at least a portion of the flexible elongation device; and the cumulative bending angle along at least a portion of the flexible elongation device. The radius of curvature along at least a portion of the flexible elongation device; the insertion depth of the flexible elongation device; or an anatomical model of the patient's anatomical structure.

37. The non-transitory computer-readable medium according to claim 35, wherein, In order to adjust the minimum tension applied to the paired traction lines by the actuator based on the bending parameters, the command, when executed, causes the computing device to: Based on the bending parameters, slack in the paired traction lines is identified; as well as The minimum tension is determined in response to the relaxation.

38. The non-transitory computer-readable medium according to claim 37, wherein, When the instruction is executed, it also causes the computing device to: The minimum tension is determined based on a second bending parameter that is different from the bending parameter.

39. The non-transitory computer-readable medium according to any one of claims 35 to 38, wherein, When the instruction is executed, it also causes the computing device to: The minimum tension may be reduced or increased based on the bending parameters.

40. The non-transitory computer-readable medium according to any one of claims 35 to 38, wherein, When the instruction is executed, it also causes the computing device to: The minimum tension is determined based on a tool that can be inserted into the lumen of the flexible elongation device.

41. A non-transitory computer-readable medium having instructions stored thereon, the instructions causing the computing device, when executed by a computing device, to: Measurement parameters of the engageable body portion of the flexible elongation device are determined based on data from one or more sensors associated with the flexible elongation device; Estimated parameters of the engageable body portion are determined based on the state of one or more actuators coupled to a pair of traction lines, the one or more actuators being configured to control the engagement of the engageable body portion by applying tension to the pair of traction lines. Slack in at least one of the paired traction lines is identified based on a comparison of the measured parameters and the estimated parameters. as well as In response to recognizing the slack, the minimum tension for the paired traction lines is adjusted.

42. The non-transitory computer-readable medium according to claim 41, wherein, The measured parameter and the estimated parameter are one or more of the following measured or estimated values: bending angle, position, or bending radius.

43. The non-transitory computer-readable medium according to claim 41 or 42, wherein, In order to determine the measurement parameters, the instruction, when executed, causes the computing device to: The shape sensor of the flexible elongation device is used to determine the measurement parameters; and Determining the estimated parameters includes using one or more actuator encoders coupled to the actuator.

44. The non-transitory computer-readable medium according to any one of claims 41 to 42, wherein, When the instruction is executed, it also causes the computing device to: Increase the minimum tension until the difference between the measured parameter and the estimated parameter decreases below a predetermined threshold.

45. The non-transitory computer-readable medium according to any one of claims 41 to 42, wherein, When the instruction is executed, it also causes the computing device to: The minimum tension is determined based on a tool that can be inserted into the lumen of the flexible elongation device.

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