Systems and methods for instrument kink detection

Abstract

The present application is titled "Systems and methods for instrument kink detection." A method includes measuring a shape of a segment of an elongated flexible instrument with a sensor and comparing the measured shape of the segment of the elongated flexible instrument to an expected shape. The method also includes determining whether the measured shape of the segment of the elongated flexible instrument differs from the expected shape by a predefined threshold.

Description

[0001] This application is a divisional application of Chinese Patent Application 201780057175.8 (PCT / US2017 / 052534), filed September 20, 2017, entitled "SYSTEMS AND METHODS FOR INSTRUMENTS BUCKLING DETECTION."

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This patent application claims priority to and the benefit of the filing date of U.S. Provisional Patent Application 62 / 397,426, filed September 21, 2016, entitled "SYSTEMS AND METHODS FOR INSTRUMENTS BUCKLING DETECTION," which is incorporated by reference in its entirety. TECHNICAL FIELD

[0004] The present disclosure relates to systems and methods for navigating a medical instrument into an access point of a patient, and more particularly to systems and methods for locating an access point. BACKGROUND

[0005] Minimally invasive medical techniques aim to reduce the amount of tissue that is damaged during a medical procedure, thereby reducing patient recovery time, discomfort, and harmful side effects. Such minimally invasive techniques can be performed through natural orifices in a patient's anatomy or through one or more surgical incisions. Through these natural orifices or incisions, an operator can insert a minimally invasive medical instrument, including a surgical, diagnostic, therapeutic, or biopsy instrument, to reach a target tissue location. When such a medical instrument is inserted into an access point, portions of the medical instrument outside the access point can be susceptible to buckling. It is desirable to use methods and systems that mitigate such buckling in order to provide improved use of medical instruments. SUMMARY

[0006] Embodiments of the present application are generally summarized by the claims that follow the detailed description.

[0007] According to some embodiments, a method includes measuring a shape of a segment of an elongated flexible instrument with a sensor and comparing the measured shape of the segment of the elongated flexible instrument to an expected shape. The method also includes determining whether the measured shape of the segment of the elongated flexible instrument differs from the expected shape by a predefined threshold.

[0008] According to some embodiments, a method includes manipulating an elongated flexible instrument with an instrument drive mechanism and measuring a shape of a segment of the elongated flexible instrument with a sensor. The segment of the elongated flexible instrument is between a distal portion of the elongated flexible instrument and a proximal instrument portion. The method also includes determining, with a control system in communication with the sensor, whether the shape of the segment of the elongated flexible instrument is buckled beyond a predefined threshold.

[0009] According to some embodiments, a system includes an instrument drive system, an elongated flexible instrument connected to the instrument drive system, and a sensor associated with the elongated flexible instrument to measure a shape of the elongated flexible instrument. The system also includes a shape constraining mechanism positioned to constrain the elongated flexible instrument at a segment between the instrument drive system and a distal end of the elongated flexible instrument, and a control system configured to manipulate the elongated flexible instrument using the instrument drive mechanism and determine whether the segment of the elongated flexible instrument within at least a portion of the shape constraining mechanism is bent beyond a predefined threshold.

[0010] According to some embodiments, a system includes a first catheter connected to a first instrument drive system, a first sensor associated with the first catheter to measure a first shape of the first catheter, and a first shape constraining mechanism positioned to constrain the first shape of the first catheter at a first catheter segment between the first instrument drive system and a distal end of the first catheter. The system also includes a second catheter connected to a second instrument drive system and sized to slidably receive a length of the first catheter, and a control system configured to manipulate the first catheter using the first instrument drive mechanism and determine whether the first catheter segment within the first shape constraining mechanism is bent beyond a first predefined threshold.

[0011] According to some embodiments, a system includes an outer catheter, an inner catheter, a sensor, and a control system, the inner catheter including a segment sized to extend within and slide relative to at least a portion of the outer catheter, the sensor associated with the inner catheter to measure a shape of the inner catheter, the control system configured to determine whether the segment of the inner catheter is bent beyond a predefined threshold.

[0012] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide a further explanation of the present disclosure as claimed. This overview, together with the following detailed description, is included herein for purposes of explaining the present disclosure but is not intended to limit the scope of the present disclosure in any way. Further, it is to be understood that the specific devices, systems, and methods named or discussed herein are not necessarily to be construed as being limiting. BRIEF DESCRIPTION OF DRAWINGS

[0013] Aspects of the present disclosure are best understood from the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that, according to the standard practice in the industry, various features are not necessarily drawn to scale. In fact, the dimensions of the various features can be arbitrarily increased or decreased for clarity. Additionally, the present disclosure can repeat certain elements of the drawings and / or letters in various examples. This repetition is for the intent of simplicity and clarity and does not necessarily mean that each discloses separate and independent claims.

[0014] Figure 1is a simplified diagram of a teleoperated medical system according to some embodiments.

[0015] Figure 2A is a simplified diagram of a medical instrument system according to some embodiments.

[0016] Figure 2B is a simplified diagram of a medical instrument with an extended medial tool according to some embodiments.

[0017] Figure 3A and Figure 3B is a simplified diagram of a side view of a patient coordinate space including a medical instrument mounted on an insertion assembly according to some embodiments.

[0018] Figure 4A and Figure 4B shows a view of a surgical coordinate space including an elongated flexible instrument positioned within a shape constraining mechanism according to one example of the principles described herein.

[0019] Figure 5 is a flowchart showing an illustrative method for detecting a kink of an elongated flexible instrument according to one example of the present disclosure.

[0020] Figure 6A and Figure 6B shows a shape data set for detecting a kink of an elongated flexible instrument.

[0021] Figure 7A and Figure 7B shows a shape data set with expected boundaries that can be used to detect a kink of an elongated flexible instrument according to one example of the principles described herein.

[0022] Figure 8 shows a directional deviation of an elongated flexible instrument from an insertion direction according to one example of the present disclosure.

[0023] Figure 9 shows a multi-instrument system utilizing a kink mechanism according to one example of the present disclosure.

[0024] Embodiments of the present disclosure and their advantages are best understood by referring to the following detailed description along with the accompanying drawings. It should be understood that identical reference numerals in the figures designate the same elements, wherein the figures are not necessarily drawn to scale, and wherein like elements are identified with like numerals in the several figures of the drawings, in which: DETAILED DESCRIPTION

[0025] In the following description, specific details are set forth describing specific details of some embodiments. Numerous specific details are set forth in order to provide a thorough understanding of the embodiments. However, it will be apparent to one skilled in the art that some embodiments can be practiced without some or all of these specific details. The particular embodiments disclosed herein are illustrative rather than restrictive. Other elements, although not specifically described herein, can be implemented by persons skilled in the art without departing from the scope and spirit of the disclosure. In addition, to avoid unnecessary repetition, one or more features shown and described in connection with one embodiment can be incorporated into other embodiments, unless specifically described otherwise or if the one or more features make the embodiment unworkable.

[0026] In some cases, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the embodiments.

[0027] The present disclosure describes various instruments and parts of instruments in terms of their states 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 (three degrees of rotational freedom— e.g., roll, pitch, and yaw). As used herein, the term "pose" refers to both the position of an object or part of an object in at least one translational degree of freedom and the orientation of that object or part of that object in at least one rotational degree of freedom (up to a total of six degrees of freedom). As used herein, the term "shape" refers to a set of poses, positions, or orientations measured along an object.

[0028] Figure 1 is a simplified diagram of a teleoperated medical system 100 in accordance with some embodiments. In some embodiments, the teleoperated medical system 100 can be suitable for use in, for example, surgical, diagnostic, therapeutic, or biopsy procedures. As shown, the medical system 100 generally includes a teleoperated manipulator assembly 102 for operating a medical instrument 104 in performing various procedures on a patient P. The teleoperated manipulator assembly 102 is mounted to or near a surgical table T. A master assembly 106 allows an operator O (e.g., a surgeon, clinician, or physician as shown) to view the intervention site and control the teleoperated manipulator assembly 102. Figure 1 Figure 1

[0029] ​​The master assembly 106 can be located at a user station (e.g., a physician's console) that is typically in the same room as the surgical table T, such as next to a surgical table where the patient P is located. However, it should be understood that the operator O can be in a different room or a completely different building from the patient P. The master assembly 106 typically includes one or more control devices for controlling the teleoperational manipulator assembly 102. The control devices can include any number of various input devices such as joysticks, trackballs, data gloves, trigger-guns, hand-operated controllers, voice recognition devices, body motion or presence sensors, and / or the like. To give the operator O a strong sense of directly controlling the instruments 104, the control devices can have the same degrees of freedom as the associated medical instrument 104. In this manner, the control devices provide the operator O with telepresence that the control devices are integral with the medical instrument 104.

[0030] In some embodiments, the control devices can have more or fewer degrees of freedom than the associated medical instrument 104 and still provide the operator O with telepresence. In some embodiments, the control devices can optionally be moved in six degrees of freedom and can also include manual input devices for actuating the instruments (e.g., for closing grasping jaws, applying an electrical potential to an electrode, providing a medication treatment, and / or the like).

[0031] The teleoperational manipulator assembly 102 supports the medical instrument 104 and can include a kinematic structure of one or more non-servo controlled links (e.g., one or more links that can be manually positioned and locked into place, often referred to as a set-up structure) and a teleoperational manipulator. The teleoperational manipulator assembly 102 can optionally include a plurality of actuators or motors that drive inputs on the medical instrument 104 in response to commands from a control system (e.g., control system 112). The actuators can optionally include drive systems that, when coupled to the medical instrument 104, can advance the medical instrument 104 into a naturally occurring or surgically created anatomical orifice. Other drive systems can move the distal end of the medical instrument 104 in multiple degrees of freedom, which can include three linear motion (e.g., linear motion along X, Y, Z Cartesian axes) degrees and three rotational motion (e.g., rotation about X, Y, Z Cartesian axes) degrees. In addition, the actuators can be used to actuate an articulatable end effector of the medical instrument 104 for grasping tissue in a biopsy device's jaws and / or the like. Actuator position sensors such as resolvers, encoders, potentiometers, and other mechanisms can provide sensor data to the medical system 100 that describes the rotation and orientation of the motor shafts. This position sensor data can be used to determine the motion of the object being manipulated by the actuators.

[0032] The teleoperational medical system 100 can include a sensor system 108 having one or more subsystems for receiving information about the instruments of the teleoperational manipulator assembly 102. Such subsystems can include a position / location sensor system, such as an electromagnetic (EM) sensor system; a shape sensor system for determining the position, orientation, velocity, speed, pose, and / or shape along one or more segments of a flexible body that can make up the medical instrument 104; and / or a visualization system for capturing images from the distal end of the medical instrument 104.

[0033] The teleoperational medical system 100 also includes a display system 110 for displaying images or representations of the surgical site and the medical instrument 104 produced by the subsystems of the sensor system 108. The display system 110 and the master assembly 106 can be oriented so that the operator O can control the medical instrument 104 and the master assembly 106 with the aid of a perceived telepresence.

[0034] In some embodiments, the medical instrument 104 can have a visualization system (discussed in greater detail below) that can include a see-scope assembly that records concurrent or real-time images of the surgical site and provides the images to the operator or operator O through one or more displays of the medical system 100 (e.g., one or more displays of the display system 110). The concurrent images can be, for example, two-dimensional or three-dimensional images captured by an endoscope positioned within the surgical site. In some embodiments, the visualization system includes an endoscopic component that can be integrally or detachably coupled to the medical instrument 104. However, in some embodiments, a separate endoscope attached to a separate manipulator assembly can be used with the medical instrument 104 to image the surgical site. The visualization system can be implemented as hardware, firmware, software, or a combination thereof that interacts with or is otherwise executed by one or more computer processors, which can include the processors of the control system 112.

[0035] The display system 110 can also display images of the surgical site and the medical instrument captured by the visualization system. In some examples, the teleoperational medical system 100 can configure the controls of the medical instrument 104 and the master assembly 106 so that the relative positions of the medical instrument are similar to the relative positions of the eyes and hands of the operator O. In this manner, the operator O can manipulate the medical instrument 104 and the hand controls as if viewing the workspace substantially as if in person. By in person, it is meant that the presentation of the images is a realistic perspective image that simulates the viewpoint of an operator who is physically manipulating the medical instrument 104.

[0036] In some examples, the display system 110 can present images of the surgical site recorded preoperatively or intraoperatively using image data from imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), fluoroscopy, thermography, ultrasound, optical coherence tomography (OCT), thermal imaging, impedance imaging, laser imaging, nanotube X-ray imaging, and / or the like. The preoperative or intraoperative image data can be presented as two-dimensional, three-dimensional, or four-dimensional (including, for example, time-based or velocity-based information) images and / or as images from models created from the preoperative or intraoperative image data sets.

[0037] In some embodiments, the display system 110 can display virtual navigation images in which the actual positioning of the medical instrument 104 is registered with preoperative or concurrent images / models (i.e., dynamically referenced) generally for the purpose of imaging-guided surgery. This can be done to present the virtual images of the internal surgical site to the operator O from the perspective of the medical instrument 104. In some examples, the perspective can be from the tip of the medical instrument 104. An image and / or other graphical or alphanumeric indicators of the tip of the medical instrument 104 can be superimposed on the virtual images to assist the operator O in controlling the medical instrument 104. In some examples, the medical instrument 104 can not be visible in the virtual images.

[0038] In some embodiments, the display system 110 can display virtual navigation images in which the actual positioning of the medical instrument 104 is registered with preoperative or concurrent images / models (i.e., dynamically referenced) generally for the purpose of imaging-guided surgery. This can be done to present the virtual images of the internal surgical site to the operator O from the perspective of the medical instrument 104. In some examples, the perspective can be from the tip of the medical instrument 104. An image and / or other graphical or alphanumeric indicators of the tip of the medical instrument 104 can be superimposed on the virtual images to assist the operator O in controlling the medical instrument 104. In some examples, the medical instrument 104 can not be visible in the virtual images.

[0039] The remote-operated medical system 100 also includes a control system 112. The control system 112 includes at least one memory and at least one computer processor (not shown) for implementing control between the medical device 104, main component 106, sensor system 108, and display system 110. The control system 112 also includes programmed instructions (e.g., a non-transitory machine-readable medium storing the instructions) to implement some or all of the methods described according to various aspects of the disclosure herein, including instructions for providing information to the display system 110. While the control system 112... Figure 1 The system is shown as a single block in the simplified schematic, but it may include two or more data processing circuits, with some processing optionally performed on or near the remote operating manipulator component 102, and other processing performed at the main component 106, and / or similar operations. The processor of the control system 112 can execute instructions, including instructions corresponding to the processes disclosed herein and described in more detail below. Any of a variety of centralized or distributed data processing architectures can be employed. Similarly, the programmed instructions may be implemented as multiple separate programs or subroutines, or they may be integrated into multiple other aspects of the remote operating system described herein. In one embodiment, the control system 112 supports wireless communication protocols such as Bluetooth, IrDA, HomeRF, IEEE 802.11, DECT, and wireless telemetry.

[0040] In some embodiments, the control system 112 may receive force and / or torque feedback from the medical device 104. In response to this feedback, the control system 112 may send a signal to the main component 106. In some examples, the control system 112 may send a signal instructing one or more actuators of the remote manipulation component 102 to move the medical device 104. The medical device 104 may extend through an opening in the patient P's body to an internal surgical site within the patient P's body. Any suitable conventional and / or specialized actuators may be used. In some examples, the one or more actuators may be separate from or integrated with the remote manipulation component 102. In some embodiments, the one or more actuators and the remote manipulation component 102 are provided as part of a remote manipulation trolley positioned near the patient P and the operating table T.

[0041] The control system 112 can optionally further include a virtual visualization system to provide navigational assistance to the operator O in controlling the medical instrument system 104 during image-guided surgery. Virtual navigation using the virtual visualization system is based on a reference to a preoperative or intraoperative data set of the acquired anatomical passageway. The virtual visualization system processes images of the surgical site imaged using imaging technology (e.g., computed tomography (CT), magnetic resonance imaging (MRI), fluoroscopy, thermography, ultrasound, optical coherence tomography (OCT), thermal imaging, impedance imaging, laser imaging, nanotube X-ray imaging, and / or the like). Software, which can be used in conjunction with manual input, is used to convert the recorded images into a segmented two- or three-dimensional composite representation of the anatomical organ or region being treated. The image data set is associated with the composite representation. The composite representation and the image data set describe various locations and shapes of the passageway and its connectivity. The images used to produce the composite representation can be recorded preoperatively or intraoperatively during the clinical procedure. In some embodiments, the virtual visualization system can use a standard representation (i.e., not patient-specific) or a mix of a standard representation and patient-specific data. The composite representation and any virtual images generated from the composite representation can represent a static pose of a deformable anatomical region during one or more motion phases (e.g., during the inhalation / exhalation cycle of a lung).

[0042] During virtual navigation surgery, the sensor system 108 can be used to compute an approximate location of the medical instrument 104 relative to the anatomy of the patient P. This location can be used to produce macroscopic (external) tracking images of the anatomy of the patient P and virtual internal images of the anatomy of the patient P. The system can implement one or more electromagnetic (EM) sensors, fiber optic sensors, and / or other sensors to register and display the medical implementation with known preoperatively recorded surgical images (e.g., those from the virtual visualization system) together. For example, U.S. Patent Application No. 13 / 107,562 (filed May 13, 2011) (disclosing "Medical System Providing Dynamic Registration of a Model of an Anatomic Structure for Image-Guided Surgery") discloses one such system, which is incorporated by reference herein in its entirety.

[0043] The teleoperated medical system 100 can also include optional operational and support systems (not shown), such as illumination systems, steering control systems, irrigation systems, and / or suction systems. In some embodiments, the teleoperated medical system 100 can include more than one teleoperational manipulator assembly and / or more than one master assembly. The exact number of teleoperational manipulator assemblies will depend on the surgical procedure and space constraints within the operating room, among other factors. The master assemblies 106 can be collocated or they can be positioned in separate locations. Multiple master assemblies allow more than one operator to control one or more teleoperational manipulator assemblies in various combinations.

[0044] Figure 2A is a simplified diagram of a medical instrument system 200 in accordance with some embodiments. In some embodiments, the medical instrument system 200 can be used as the medical instrument 104 in an image-guided medical procedure performed using the teleoperated medical system 100. In some examples, the medical instrument system 200 can be used in a non-teleoperational exploratory procedure or a procedure involving a conventionally manually operated medical instrument (such as an endoscopy). Alternatively, the medical instrument system 200 can be used to collect (i.e., measure) a set of data points corresponding to a location within an anatomical passageway of a patient, such as the patient P.

[0045] The medical instrument system 200 includes an elongate device 202 (such as a flexible catheter) coupled to a drive unit 204. The elongate device 202 includes a flexible body 216 having a proximal end 217 and a distal end or tip portion 218. In some embodiments, the flexible body 216 has an outer diameter of approximately 3 mm. Other flexible body outer diameters can be larger or smaller.

[0046] The medical instrument system 200 also includes a tracking system 230 for determining a position, orientation, velocity, speed, pose, and / or shape of the distal end 218 and / or one or more segments 224 along the flexible body 216 using one or more sensors and / or imaging devices as described in further detail below. The entire length of the flexible body 216 between the distal end 218 and the proximal end 217 can effectively be divided into segments 224. If the medical instrument system 200 is consistent with the medical instrument 104 of the teleoperated medical system 100, the tracking system 230. The tracking system 230 can optionally be implemented as hardware, firmware, software, or a combination thereof that interacts with or is otherwise executed by one or more computer processors, which can include Figure 1 the processors of the control system 112 in the master assembly 106.

[0047] The tracking system 230 can optionally track one or more of the distal end 218 and / or the segments 224 using a shape sensor 222. The shape sensor 222 can optionally include an optical fiber aligned with the flexible body 216 (e.g., disposed within an internal channel (not shown) or mounted externally). In one embodiment, the optical fiber has a diameter of about 200 pm. In other embodiments, the dimensions can be larger or smaller. The optical fiber of the shape sensor 222 forms a fiber optic bend sensor for determining the shape of the flexible body 216. In an alternative, an optical fiber including fiber Bragg gratings (FBGs) is used to provide strain measurements of the structure in one or more dimensions. Various systems and methods for monitoring the shape and relative position of an optical fiber in three dimensions are described in U.S. Patent Application No. 11 / 180,389 (filed July 13, 2005) (disclosing “Fiber optic position and shape sensing device and method relating thereto”), U.S. Patent Application No. 12 / 047,056 (filed July 16, 2004) (disclosing “Fiber-optic shape and relative position sensing”), and U.S. Patent No. 6,389,187 (filed June 17, 1998) (disclosing “Optical Fibre Bend Sensor”), the disclosures of which are incorporated by reference herein in their entireties. The sensors in some embodiments can employ other suitable strain sensing techniques, such as Rayleigh scattering, Raman scattering, Brillouin scattering, and fluorescence scattering. In some embodiments, the shape of the elongated device can be determined using other techniques. For example, a history of the distal pose of the flexible body 216 can be used to reconstruct the shape of the flexible body 216 over a certain time interval. In some embodiments, the tracking system 230 can optionally and / or additionally track the distal end 218 using the position sensor system 220. The position sensor system 220 can be one component of an EM sensor system, where the position sensor system 220 includes one or more electrically conductive coils that can be subjected to an externally generated electromagnetic field. Each coil of the EM sensor system 220 then generates an induced electrical signal having a characteristic that depends on the position and orientation of the coil relative to the externally generated electromagnetic field. In some embodiments, the position sensor system 220 can be configured and positioned to measure six degrees of freedom, e.g., three position coordinates X, Y, Z and three orientation angles indicative of pitch, yaw, and roll of a base point, or five degrees of freedom, e.g., three position coordinates X, Y, Z and two orientation angles indicative of pitch and yaw of a base point.Further description of position sensor systems is provided in U.S. Patent No. 6,380,732 (filed August 11, 1999) (disclosing "Six-Degree of Freedom Tracking System Having a Passive Transponder on the Object Being Tracked"), which is incorporated by reference herein in its entirety.

[0048] In some embodiments, the tracking system 230 can alternatively and / or additionally rely on historical pose, position, or orientation data stored for known points of the instrument system along a cycle of alternating motion, such as respiration. This stored data can be used to form shape information about the flexible body 216. In some examples, a series of position sensors (not shown), such as electromagnetic (EM) sensors similar to those in the position sensors 220, can be positioned along the flexible body 216 and then used for shape sensing. In some examples, historical data gathered from one or more of these sensors during a procedure can be used to represent the shape of the elongate device 202, particularly if the anatomical passageway is largely static.

[0049] The flexible body 216 includes a channel 221 sized and shaped to receive the medical instrument 226. Figure 2Bis a simplified diagram of a flexible body 216 with an extended medical instrument 226 according to some embodiments. In some embodiments, the medical instrument 226 can be used for procedures such as surgery, biopsy, ablation, illumination, irrigation, or aspiration. The medical instrument 226 can be deployed through a channel 221 of the flexible body 216 and used at a target location within an anatomical structure. The medical instrument 226 can include, for example, an image capture probe, a biopsy instrument, a laser ablation fiber, and / or other surgical, diagnostic, or therapeutic tools. The medical tools can include end effectors with single working members, such as a scalpel, a blunt blade, an optical fiber, an electrode, and / or the like. Other end effectors can include, for example, forceps, graspers, scissors, clip appliers, and / or the like. Other end effectors can also include electrically activated end effectors, such as electrosurgical electrodes, transducers, sensors, and / or the like. In various embodiments, the medical instrument 226 is a biopsy instrument that can be used to remove sample tissue or a cell sample from a target anatomical location. The medical instrument 226 can also be used with an image capture probe within the same flexible body 216. In various embodiments, the medical instrument 226 can be an image capture probe that includes a distal portion with a stereoscopic or monoscopic camera at or near the distal end 218 of the flexible body 216 for capturing images (including video images) that are processed by a visualization system 231 for display and / or provided to a tracking system 230 to support tracking of the distal end 218 and / or one or more segments 224. The image capture probe can include a cable coupled to the camera for transmitting captured image data. In some examples, the image capture instrument can be a fiber optic bundle coupled to the visualization system 231, such as a fiberscope. The image capture instrument can be single-spectral or multi-spectral, such as capturing image data in one or more of the visible, infrared, and / or ultraviolet spectrums. Alternatively, the medical instrument 226 itself can be the image capture probe. The medical instrument 226 can be advanced from an opening of the channel 221 for a procedure and then retracted into the channel when the procedure is complete. The medical instrument 226 can be removed from the proximal end 217 of the flexible body 216 or from another optional instrument port (not shown) along the flexible body 216.

[0050] The medical instrument 226 can additionally house cables, linkages, or other actuation controls (not shown) extending between its proximal and distal ends to controllably bend the distal end of the medical instrument 226. Steerable instruments are described in detail in U.S. Patent No. 7,316,681 (filed October 4, 2005) (disclosing "Articulated Surgical Instrument for Performing Minimally Invasive Surgery with Enhanced Dexterity and Sensitivity") and U.S. Patent Application No. 12 / 286,644 (filed September 30, 2008) (disclosing "Passive Preload and Capstan Drive for Surgical Instruments"), which are incorporated herein by reference in their entireties.

[0051] The flexible body 216 can also house cables, linkages, or other steering controls (not shown) extending between the drive unit 204 and the distal end 218 to controllably bend the distal end 218, e.g., as shown by the dashed depiction 219 of the distal end 218. In some examples, at least four cables are used to provide independent "up-down" steering to control the pitch of the distal end 218 and "left-right" steering to control the yaw of the distal end 281. Steerable elongate devices are described in detail in U.S. Patent Application No. 13 / 274,208 (filed October 14, 2011) (disclosing "Catheter with Removable Vision Probe"), which is incorporated herein by reference in its entirety. In embodiments where the medical instrument system 200 is actuated by a teleoperational assembly, the drive unit 204 can include a drive input that is removably coupled to and receives power from a drive element (e.g., an actuator) of the teleoperational assembly. In some embodiments, the medical instrument system 200 can include a grip feature, a manual actuator, or other components for manually controlling the movement of the medical instrument system 200. The elongate device 202 can be steerable, or, alternatively, the system can be non-steerable and lack integrated mechanisms for operator control of the bending of the distal end 218. In some examples, the medical instrument can be defined in a wall of the flexible body 216 by one or more lumens through which it is deployed and used at a target surgical location.

[0052] In some embodiments, the medical instrument system 200 can include a flexible bronchial instrument, such as a bronchoscope or bronchial catheter, for examination, diagnosis, biopsy, or treatment of the lungs. The medical instrument system 200 is also suitable for navigation and treatment of other tissue through a naturally or surgically created connection passage in any of a variety of anatomic systems, including the colon, intestines, kidneys and renal calyces, brain, heart, circulatory system including vasculature, and / or the like.

[0053] Information from the tracking system 230 can be sent to a navigation system 232, where it is combined with information from the visualization system 231 and / or preoperatively obtained models to provide real-time position information to the operator or other operators. In some examples, the real-time position information can be displayed on the display system 110 of Figure 1 for control of the medical instrument system 200. In some examples, Figure 1 The control system 112 of may utilize the position information as feedback for positioning the medical instrument system 200. Various systems for registering and displaying surgical instruments with surgical images using fiber optic sensors are provided in U.S. Patent Application No. 13 / 107,562 (filed May 13, 2011) (disclosing "Medical System Providing Dynamic Registration of a Model of an Anatomic Structure for Image-Guided Surgery"), which is incorporated by reference herein in its entirety.

[0054] In some examples, the medical instrument system 200 can be teleoperated within the medical system 100 of Figure 1 In some embodiments, Figure 1 The teleoperational manipulator assembly 102 of may be replaced by direct operator controls. In some examples, the direct operator controls can include various handles and operator interfaces for handheld operation of the instrument.

[0055] Figure 3A and Figure 3B are simplified diagrams of a side view of a patient coordinate space including a medical instrument mounted on an insertion assembly in accordance with some embodiments. As Figure 3A and Figure 3BAs shown, the surgical environment 300 includes a patient P positioned on a table T. The patient P can be stationary in the surgical environment in the sense that the patient’s gross motion is limited by sedation, restraint, and / or other means. Circulatory anatomical motion including respiration and cardiac motion of the patient P can continue unless the patient is asked to hold his or her breath to temporarily suspend respiratory motion. Thus, in some embodiments, data can be collected at a particular phase of respiration and tagged and identified with that phase. In some embodiments, the phase in which data is collected can be inferred from physiological information collected from the patient P. In the surgical environment 300, a point collection instrument 304 is coupled to an instrument carriage 306. In some embodiments, the point collection instrument 304 can use EM sensors, shape sensors, and / or other sensor modalities. The instrument carriage 306 is mounted to an insertion table 308 that is fixed within the surgical environment 300. Alternatively, the insertion table 308 can be movable but have a known position (e.g., via tracking sensors or other tracking devices) within the surgical environment 300. The instrument carriage 306 can be a component of a teleoperational manipulator assembly (e.g., the teleoperational manipulator assembly 102) that is coupled to the point collection instrument 304 to control insertion motion (i.e., motion along the A-axis) of a distal end 318 of an elongate device 310 and, optionally, motion of the distal end 318 of the elongate device 310 in multiple directions including yaw, pitch, and roll. The instrument carriage 306 or the insertion table 308 can include actuators, such as servo motors (not shown), that control motion of the instrument carriage 306 along the insertion table 308.

[0056] The elongate device 310 is coupled to an instrument body 312. The instrument body 312 is coupled and fixed relative to the instrument carriage 306. In some embodiments, a fiber optic shape sensor 314 is fixed at a proximal point 316 on the instrument body 312. In some embodiments, the proximal point 316 of the fiber optic shape sensor 314 can move with the instrument body 312, but the position of the proximal point 316 can be known (e.g., via tracking sensors or other tracking devices). The shape sensor 314 measures a shape from the proximal point 316 to another point, such as the distal end 318 of the elongate device 310. The point collection instrument 304 can be substantially similar to the medical instrument system 200.

[0057] Position measurement device 320 provides information about the position of instrument body 312 as it is moved along insertion axis A on insertion stage 308. Position measurement device 320 can include a rotary transformer, an encoder, a potentiometer, and / or other sensors that determine the rotation and / or orientation of actuators that control the motion of instrument carriage 306 and thus the motion of instrument body 312. In some embodiments, insertion stage 308 is linear. In some embodiments, insertion stage 308 can be curved or have a combination of curved and linear segments.

[0058] Figure 3A Instrument body 312 and instrument carriage 306 are shown along insertion stage 308 in a retracted position. In this retracted position, proximal point 316 is located at a position Lo on axis A. In this position along insertion stage 308, one component of the positioning of proximal point 316 can be set to zero and / or another reference value to provide a fiducial reference to describe the position of instrument carriage 306 on insertion stage 308 and thus the position of proximal point 316 on insertion stage 308. With instrument body 312 and instrument carriage 306 in this retracted position, distal end 318 of elongate device 310 can be positioned just inside the entry orifice of patient P. Also in this position, position measurement device 320 can be set to zero and / or another reference value (e.g., I = 0). Foldable shape constraint device 272 supports elongate device 310 between instrument body 312 and the entry orifice of patient P. Foldable shape constraint device 272 constrains flexible elongate device 310 to a narrow channel defined by the shape constraint device and supports the instrument body from bending as it is pushed forward (distally) along axis A. Consistent with embodiments of the present disclosure, a device can be considered to be bent if it assumes a nonlinear shape, particularly a nonlinear shape that exceeds a predefined threshold. The predefined threshold need not be associated with an immediate mechanical failure, but can be a shape associated with reduced accuracy, diminished control, predicted failure, or other suboptimal performance. The predefined threshold can depend on another measurement, such as insertion distance, friction detection, obstacle detection, distal curvature detection, or planned navigation route.

[0059] In Figure 3BIn this position, instrument body 312 and instrument carriage 306 have advanced along the linear track of insertion table 308, and distal end 318 of elongate device 310 has advanced into patient P. In this advanced position, proximal point 316 is at a position L1 on axis A. In some examples, an encoder and / or other position data from one or more actuators that control movement of instrument carriage 306 along insertion table 308 and / or one or more position sensors associated with instrument carriage 306 and / or insertion table 308 are used to determine a position Lx of proximal point 316 relative to position L0. In some examples, position Lx can also be used as an indication of a distance or insertion depth of distal end 318 of elongate device 310 into a passageway in the anatomy of patient P.

[0060] As instrument body 312 is advanced toward the patient entry orifice, the foldable shape constraint device 272 helps prevent the flexible elongate device 310 from kinking. The length of the flexible elongate device 310 housed within device 272 has an intended straight linear shape. The shape of the flexible elongate device 310 within the device can be measured by shape sensor 314. If the measured shape of shape sensor 314 exhibits a non-linear shape or kink that exceeds a predefined threshold, an error can be reported, indicating that the shape constraint device failed to maintain the intended configuration of the flexible elongate instrument, and thus the intended configuration of the shape sensor.

[0061] Figure 4A and Figure 4B A view of a surgical coordinate space 400 is shown, including a flexible elongate instrument 404 (e.g., device 310, 202) positioned within a shape constraint device 408. As previously described, the flexible elongate instrument can be a catheter. Shape constraint device 408 can collapse as the catheter is inserted into entry port 406 and expand as the catheter is retracted from the entry port. Catheter 404 is coupled to instrument body 402. Catheter 304 also includes a shape sensor 412. Figure 4A A view of shape constraint device 408 in an expanded position is shown, while Figure 4B A view of shape constraint device in a collapsed position is shown.

[0062] Shape sensor 412 generates shape data that can be used to determine the shape of catheter 404. The shape data can be used to determine the pose of distal end 407 of catheter 404 within surgical coordinate space 400. For example, if the location of a particular portion of catheter 404 has been learned or tracked in surgical coordinate space 400 (i.e., base 403 of catheter 404), then the shape data can be used to determine the location of any point along catheter 304 in surgical coordinate space 400. Various shape sensing systems can be used, alternatively or in combination, to generate the shape data.

[0063] In one example, shape sensor 412 is a fiber optic shape sensor. Such a shape sensor can include one or more fiber optic cables extending along the length of catheter 404. The fiber optic shape sensor can include one or more optical cores. In some cases, the fiber optic shape sensor can include one or more optical fibers, each having one or more optical cores. As described above, the cores can include fiber Bragg gratings to provide strain measurements in one or more dimensions. In other alternatives, sensors employing other strain sensing technologies can be suitable. In one example, the fiber optic shape sensor utilizes an interrogation system (not shown) positioned proximal to base 403 of catheter 404. In operation, the interrogation system generates light and detects returned light to determine the current shape of the fiber optic shape sensor. The interrogation system can then create data representing the detected light. This data can be analyzed to determine the position and orientation of any point along the length of catheter 404. Because base 403, which acts as a reference fixture, can have a fixed, known, or tracked position in surgical coordinate space 400, the position and orientation of any point along catheter 404 relative to the surgical coordinate space can be determined from the sensor data.

[0064] In one example, shape sensor 412 includes a plurality of electromagnetic (EM) sensors along the length of catheter 404. As described above, the EM sensors can include one or more electrically conductive coils that can be subjected to an electromagnetic field generated by an EM transmitter (not shown). Each coil of the EM sensor then generates an induced electrical signal having characteristics that depend on the position and orientation of the coil relative to the electromagnetic field generated by the EM transmitter. Thus, the EM sensor can measure six degrees of freedom, e.g., three position coordinates X, Y, Z and three orientation angles indicating pitch, yaw, and roll of a base point, or five degrees of freedom, e.g., three position coordinates X, Y, Z and two orientation angles indicating pitch and yaw of a base point.

[0065] In one example, shape sensor 412 includes optical markers for analyzing imaging data obtained by a video camera system. For example, a plurality of video cameras or still cameras can be pointed at portion 410 of catheter 404 outside of entry port 406. The cameras can be stereoscopic so as to obtain data representing the position of catheter 404 within surgical coordinate space 400. The optical markers can include varying colors, reflectivity, texture, or other features that can allow for more efficient analysis of the imaging data generated by the video cameras.

[0066] The instrument body 402 can be substantially similar to the body 312 and is connected to an instrument carriage 416, which can be part of a teleoperational manipulator assembly (e.g., assembly 102), which can be moved within a surgical coordinate space along an insertion table 418 to insert and retract the catheter 404 from an access port 406. The teleoperational manipulator assembly can be part of a teleoperational system (e.g., system 100) that includes a control system 414 having a processor and memory and software (machine readable instructions) to operate the catheter 404. For example, the control system can operate motors that control movement of the instrument drive mechanism 402 as well as other mechanisms that control pull wires and manipulate the distal end of the catheter 404. The control system 414 can also process data obtained from the shape sensor 412 to determine the shape of the catheter 404 in real time.

[0067] The catheter 404 can be inserted into a natural orifice of a patient or an incision created by a surgical procedure. In the case where the orifice is the patient’s mouth, the access port 406 can be, for example, an endotracheal tube. In the case where the orifice is an incision created by a surgical procedure, the access port 406 can be, for example, a trocar cannula.

[0068] A shape restraint device 408 is positioned between the instrument body 402 and the access port 406. The shape restraint device 408 can limit bending when the catheter 404 is inserted into the access port 406. Various types of shape restraint devices can be used based on the principles described herein. For example, the shape restraint device 408 may include a series of linkages as described in U.S. Provisional Patent Application 61 / 823,666, filed May 15, 2013, entitled “Guide Apparatus for Delivery of a Flexible Instrument and Methods of Use,” which is incorporated herein by reference in its entirety. In some examples, the shape constraint device 408 may include a series of holding members and a series of supporting members, as described in U.S. Provisional Patent Application No. 62 / 029,917, filed July 28, 2014, entitled “Guide Apparatus for Delivery of a Flexible Instrument and Methods of Use,” and U.S. Provisional Patent Application No. 62 / 359,957, filed July 8, 2016, entitled “Guide Apparatus For Delivery Of An Elongate Device And Methods Of Use,” both of which are incorporated herein by reference in their entirety.

[0069] The shape constraint device 408 typically helps prevent bending, sagging, or other non-linear morphologies of the conduit 404; however, to prevent friction from forming between the conduit and the device, the device may be designed to be slightly larger than the conduit (e.g., 2-10 mm). Due to this dimensional difference, the conduit 404 will not maintain a precisely linear shape in the advance position, and therefore the portion of the conduit 404 outside the inlet port 406 will be longer than length D1. Shape sensor data from sensor 412 can be used to determine the shape of the conduit 404 along length D1. If the determined shape exceeds a threshold value for the expected (typically linear) shape, the system 414 may perform actions such as user warnings, feedback signals to stop further advance, or actions to correct the applied forces on the shape.

[0070] The control system 414 can be used to determine the minimum length of the portion 410 of the conduit 404 outside the inlet port 406. For example... Figure 4BAs shown, the length of portion 410 decreases as catheter 404 is inserted into entry port 406. Various techniques can be used to determine the minimum length of portion 410 at any given time during operation of catheter 404. In one example, data from an insertion sensor (e.g., an encoder) associated with a motor of instrument carriage 416 that drives catheter 404 can be used to determine the minimum length of portion 410. For example, in a retracted position, a proximal point 420 on instrument body 402 is located at a position L0 on axis A. In this position along insertion stage 418, one component of the location of proximal point 420 can be set to zero and / or another reference value to provide a fiducial reference to describe the position of instrument carriage 416 on insertion stage 418, and thus the position of proximal point 420 on insertion stage 418. With instrument body 402 and instrument carriage 416 in this retracted position, distal end 407 of flexible elongate instrument 404 can be positioned just inside entry port 406. In this retracted position, the minimum length of portion 410 outside of entry port 406 is length Dl. If instrument 404 is substantially straight, the minimum length of portion 410 can be approximately the same as the minimum length of portion 410. Also in this position, the insertion sensor can be set to an initial value (e.g., zero and / or another reference value). In Figure 4B In an advanced position, instrument body 402 and instrument carriage 416 have advanced along insertion stage 418, and the distal end of flexible elongate instrument 404 has advanced through entry port 406. In this advanced position, proximal point 420 is located at a position LI on axis A. Data from the insertion sensor indicates the distance between L0 and LI. More specifically, data from an encoder sensor can indicate a change in the state of the motor. The state of the motor can include the current rotational position of the motor and the number of revolutions the motor has made from a reference state. The minimum length of portion 410 outside of entry port 406 is length D2, which is approximately length Dl less the advanced distance between L0 and LI. If portion 410 outside of entry port 406 is bent, the actual length of portion 410 can exceed length D2.

[0071] Control system 414 can analyze the shape of catheter 404 during catheter operation. For example, control system analyzes data from shape sensor 412 to determine the current shape of catheter 404. Control system 414 then compares the shape data received from the shape sensor to an expected shape. Various techniques can be used to define the expected shape. For example, as will be described in further detail below, comparing the shape data to the expected shape can include determining whether the current shape of catheter 404 exceeds an expected boundary. Comparing the shape data to the expected shape can also include determining that a portion of the catheter has deviated from axis A by a predefined distance. Comparing the shape data to the expected shape can also include determining directional movement of catheter 404 in a direction orthogonal to the insertion direction.

[0072] If the control system 414 determines that the current shape differs from the expected shape by a predetermined amount, the control system can trigger a kink mitigation action. In one example, the kink mitigation action includes reporting a warning or error message to an operator of the catheter 404. In one example, the kink mitigation action includes transitioning the catheter control system to a safe state. The safe state is a state in which further movement of the catheter is prohibited. In some examples, the kink mitigation action can include indicating to the user the precise portion of the catheter 404 that has exceeded the expected shape. In some examples, the kink mitigation action can include automatically retracting or adjusting the position of the catheter 404 until the current shape of the catheter 404 returns to a state closer to the expected shape. In one example, the kink mitigation action can include modifying the shape of the shape-constraining device to reduce the measured kink. For example, the shape-constraining device can be controlled to deform in a direction opposite the measured kink to return the catheter to the expected shape. Alternatively, if the catheter is kinked due to friction with the constraining device, the constraining device can be rotated about its longitudinal axis to overcome the static friction.

[0073] Figure 5 is a flow diagram illustrating an illustrative method 450 for detecting kinks of an elongate flexible instrument. The method 450 is shown in Figure 5 as a set of operations or processes 452-456. Not all of the illustrated processes 452-456 can be performed in all embodiments of the method 450. Additionally, Figure 5 one or more processes not explicitly shown in can be included before, after, between, or as part of the processes 452-456. In some embodiments, one or more of the processes described can be implemented at least in part 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 processors of the control system 112 or 414) can cause the one or more processors to perform one or more of the processes described.

[0074] According to the present example, the method 450 includes a step 452 for measuring a shape of a segment of the elongate flexible instrument between the anatomical access channel (e.g., the access port 406 at the patient's mouth or a cannula at an opening created by a surgical procedure) and the proximal instrument portion (e.g., the instrument body 402) with a sensor. The sensor can be, for example, a fiber optic shape sensor, a series of EM sensors, or an imaging sensor. The method 450 also includes a step 454 for comparing the measured shape of the segment of the elongate flexible instrument to an expected shape. The expected shape can be a line corresponding to a reference axis (e.g., a central axis or a base axis) passing through a shape-constraining device (e.g., the kink-resistant mechanism 408 placed between the anatomical access channel and the proximal instrument portion). Alternatively, the expected shape can be a shape having a predetermined cumulative deviation from an axis (e.g., a central axis or a base axis). Alternatively, the expected shape can be any shape that fits within a predefined volume. Alternatively, the expected shape can be a shape in which the distal end is a predefined distance from the proximal end. The method 450 also includes a step 456 for determining whether the measured shape of the segment of the elongate flexible instrument differs from the expected shape by a predefined threshold. Optionally, the method can also include triggering a mitigation action, such as providing a warning to an operator, applying a corrective force via a teleoperational system, entering a safe state, or providing instructions to a user for a corrective action.

[0075] Figure 6A A shape data 500 is shown that is obtained from a shape sensor (such as the sensor 412) within a segment of a flexible instrument between an access port and a proximal instrument body. In one example, the segment can be constrained by a shape-constraining device 408. An axis 502 is an expected shape of the segment. In various examples, the expected shape 502 can represent a central axis passing through the shape-constraining device 408 or a base axis along a gravity bottom of the shape-constraining device. A predefined threshold 504 is set at a distance 510 from the expected shape 502 based on a consistency of the expected shape required to achieve a desired level of accuracy for an insertion movement. The threshold can be constant along the length of the shape or can vary according to an expected deviation amount at different points along the expected shape. In this example, the shape data 500 has a deviation 506 that exceeds the predefined threshold 504. Accordingly, the deviation 506 will trigger a mitigation action. In this example, the shape data 500 also has deviations 508, 512 that are each less than the predefined threshold 504. Neither deviation 508 nor deviation 512 will trigger a mitigation action by itself. In one example, the cumulative size of the deviations 508 and 512 can exceed the predefined threshold 504. This cumulative deviation can trigger a mitigation action.

[0076] The predefined threshold can variably depend on the measurement or on a known or detected condition. For example, when the catheter experiences friction within the anatomical passageway due to an obstruction or tortuous path, it can be expected that the catheter bends within the shape constraining device. In such a case, the predefined threshold can be enlarged. For example, the threshold can be increased when a high input force is measured with the sensor or reference insertion motor current. For example, the threshold can be increased when the distal end of the catheter has a sufficiently curved shape within the patient anatomy. For example, the threshold can be increased when the planned navigation path is predicted to be tortuous.

[0077] In some examples, a kink mitigation action is triggered if one deviation exceeds another deviation by a predetermined value. In one example, a kink mitigation action is triggered if deviation 506 is greater than any other deviation 508, 512 by a predetermined value. In some examples, a kink mitigation action is triggered if a particular deviation 506 exceeds a more distal deviation 508 or deviation 512 by a predetermined value.

[0078] Figure 6B Alternative techniques for determining whether a measured shape of a segment of a flexible instrument differs from an expected shape are shown. As previously described, an encoder or other position sensor can be used to determine the distance that the proximal instrument body 402 is advanced (i.e., the distance between L O and Li. In this example, shape data 550 is obtained from shape sensor 412. A proximal end 552 of shape data 550 can correspond to a fixed point relative to proximal instrument body 402 (e.g., point 420 or catheter end 403). A distal end 554 of shape data 550 can correspond to distal end 407 of catheter or the distal end of portion 410 of catheter 404 outside of entry port 406. Distal end 554 of shape data 550 can be determined by a shape perturbation caused by entry port 406, a temperature change at entry port 406, or other indicator that the catheter has entered the entry port. If the linear distance D3 between data points 552 and 554 is less than the distance between L O and Li, this comparison can indicate that catheter 404 has experienced a kink. If the distance D3 exceeds the distance between L O and Li by a predefined threshold, a mitigation action can be triggered to, for example, alert a user of the kink or to correct the kink.

[0079] Figure 7A and Figure 7BAn expected boundary 602 is shown that can be used to detect a bend of an elongated flexible instrument 604, such as instrument 404. The expected shape of method 450 can be any shape suitable within the three-dimensional volume defined by boundary 602. In one example, expected boundary 602 defines a volume within surgical coordinate space 400 that corresponds to the volume defined by shape-constraining device 408. The volume can have a substantially tubular shape. The tubular shape can be substantially straight or arcuate. In some embodiments, the volume defined by expected boundary 602 can substantially match the volume defined by shape-constraining device 408. In some embodiments, the volume defined by expected boundary 602 can be scaled to a volume that is slightly larger or slightly smaller than the volume defined by shape-constraining device 408. Expected boundary 602 can be defined with respect to an axis 605 along which an elongated flexible instrument from which shape data 504 is obtained is expected to be inserted. Expected boundary 602 represents a predefined threshold that, if exceeded by shape data 604, results in a mitigation action being triggered.

[0080] In some examples, expected boundary 602 can correspond to an anatomical lumen. For example, various medical imaging techniques, such as CT scans, can be used to map the anatomy of a patient. When a flexible instrument is inserted into the anatomy of a patient, expected boundary 602 can be defined based on the geometry of the anatomical lumen in which a specified portion of the flexible instrument from which shape data 404 is obtained is currently present.

[0081] Figure 7A An example is shown in which shape data 604 remains within expected boundary 602. While shape data 604 is shown to have a slight bend 603, the bend does not exceed the predefined threshold defined by expected boundary 602. However, Figure 7B Shape data 606 is shown that is shaped such that a portion 608 of the shape exceeds expected boundary 602. In this case, a control system (e.g., control system 414) would trigger a mitigation action. By comparing shape data from a shape sensor (e.g., sensor 412) to expected boundary 602 defined with respect to an insertion axis through a shape-constraining mechanism, the control system can determine that a portion 608 of shape 604 exceeds expected boundary 602.

[0082] Figure 8 An elongated flexible instrument 652 is shown deviating from the direction of insertion direction 658 (e.g., along axis A) in order to detect a bend. In particular, a control system can analyze shape sensor data in real-time to determine whether a particular portion is moving in a direction that is substantially orthogonal to insertion direction 658. Figure 8Portions 654 of instrument 652 are shown moving in a first direction 660 that is substantially orthogonal to the insertion direction 658. In addition, portions 656 of instrument 652 are moving in a second direction 662 that is opposite the first direction and substantially orthogonal to the insertion direction 658. If a particular portion moves a predetermined distance or for a predetermined period of time in a direction 660, 662 that is orthogonal to the insertion direction 658, a mitigation action can be triggered. In the present example, portions 654 can exceed the predetermined distance or time period, while portions 656 do not exceed the predetermined distance or time period. Mitigation actions can additionally or alternatively be triggered if a local curvature (e.g., a minimum bend radius) or a cumulative curvature (e.g., a total bend angle) of a shape in a shape constraint device exceeds a particular threshold.

[0083] Figure 9 A multiple instrument system 701 is shown that utilizes shape constraint devices between multiple instruments and between the instrument drive mechanisms and the entry port. The medical instrument system 701 (e.g., instruments 104, 200) includes an outer catheter 728, an inner catheter 726, and a medical tool 724. According to the present example, each medical instrument is connected to a teleoperational manipulator assembly 702, 712, 718 (e.g., manipulator assembly 102).

[0084] Manipulator assembly 702 includes a base 704a, a motion arm assembly 709a (which includes a set of links 706a, a set of joints 708a), and an end effector mechanism 710. Joints 708a can include motors or other actuators to drive movement of arm 709a in one or more degrees of freedom. While the present example shows three links 706a coupled by two joints 708a, other examples can have other numbers of links 706 and joints 708. In some examples, the links can be telescoping links that can extend a predetermined distance. The links can pivot about the joints in order to move the end effector mechanism to a desired position within a surgical coordinate system. Some joints can allow rotation in only one plane. Other joints can allow rotation in multiple planes.

[0085] The combination of links 706a and joints 708a can provide movement of the end-effector mechanism 710 in six degrees of freedom, which can include three linear motion (e.g., linear motion along X, Y, Z Cartesian axes) degrees and three rotational motion (e.g., rotation about X, Y, Z Cartesian axes) degrees. The arm 709a can include wiring, circuitry, and other electronics to carry power and control signals from the control system 703 (e.g., control system 112) to the actuators and instruments and instrument end effectors coupled to the end-effector mechanism 710. Actuator position sensors (e.g., resolvers, encoders, potentiometers, and other mechanisms) can provide sensor data to the control system describing the rotation and orientation of the motor shafts. This position sensor data can be used to determine the motion of objects manipulated by the motors. For example, a joint can have a sensor that can determine the rotational position of the joint or determine the angle at which two links connected by the joint are currently positioned. Additionally, if a link is extendable, such a link can include a sensor to determine the distance the link is currently extended. In this way, the position of the end-effector mechanism relative to the base can be determined based on data from such sensors. In particular, the control system 703 can process data received by such sensors and determine the position of the end-effector mechanisms 710, 716, 722 relative to their respective bases. Additionally, because the medical tools 724 and catheters 726, 728 can include shape and position sensors as described above, the position and orientation of the distal ends of each of the medical tools and catheters relative to each other and a fixed point (e.g., one of the bases 704) can be known within the surgical coordinate space. Thus, the position and orientation of the distal ends of the medical tools and catheters relative to each other and a fixed point (e.g., one of the bases 704) can be determined within the surgical coordinate space.

[0086] The manipulator assembly 712 includes a base 704b, a motion arm assembly 709b (which includes a set of links 706b, a set of joints 708b), and an end-effector mechanism 716. The manipulator assembly 718 includes a base 704c, a motion arm assembly 709c (which includes a set of links 706c, a set of joints 708c), and an end-effector mechanism 722. Actuation and control of the assemblies 712, 718 can be substantially similar to the assembly 702.

[0087] The bases 704a, 704b, 704c can be portable such that each manipulator assembly can be individually positioned and secured in the surgical space near the patient as needed. Alternatively, one or more of the manipulator assemblies can be coupled to a cart or other common platform that can be positioned in the surgical space near the patient.

[0088] In Figure 9In the example of FIG. 7, a medical tool 724 is connected to the end effector 710. Actuation of the tool 724 can be controlled at least in part by the end effector 710 by power and control signals. An inner catheter 726 is connected to the end effector 716 by a connector mechanism 714. The connector mechanism 714 can be used to guide the medical tool 724 into the inner catheter 726. Actuation of the inner catheter 726 can be controlled at least in part by the end effector 716 by power and control signals. An outer catheter 728 is connected to the end effector 722 by a connector mechanism 720. The connector mechanism 720 can be used to guide the inner catheter 726 into the outer catheter 728. Actuation of the outer catheter 728 can be controlled at least in part by the end effector 722 by power and control signals. The medical tool 724 is sized and shaped to fit, slide, and rotate within the inner catheter 726. Additionally, the inner catheter 726 is sized and shaped to fit, slide, and rotate within the outer catheter 728. The inner and outer catheters 726, 728 can be similar to the catheter 202 described above and shown in FIG. 6. The medical tool 724 can be one of a variety of medical tools, including a biopsy tool, a capture probe, an ablation probe, or other surgical or diagnostic tool. In alternative embodiments, one or both of the catheters can be omitted. Figure 2A

[0089] The three end effectors 710, 716, 722 can be controlled individually to move the medical tool 724 and the catheters 726, 728 as desired. For example, to insert the inner catheter 726 further into the outer catheter 728, the end effector 716 can be moved closer to the end effector 722. To insert the medical tool 724 further into both the inner catheter 726 and the outer catheter 728, the end effector 710 can be moved closer to the end effector 716.

[0090] The end effectors 710, 716, 722 can be moved to insert the distal end of the medical tool 724 and the catheters 726, 728 through the access port 736 into a patient. As described above, the tool and catheters can be inserted through a natural or surgically created orifice.

[0091] ​A first shape constraining device 740 can be placed between the first end mechanism 710 and the second end mechanism 716. Thus, the first shape constraining device 740 helps reduce bending of the medical tool 724 as it is inserted into the inner catheter 726. A second shape constraining device 742 is placed between the second end mechanism 714 and the third end mechanism 722. Thus, the second shape constraining device 742 helps reduce bending of the inner catheter 726 as it is inserted into the outer catheter 728. Similar to the shape constraining device 308 described above, a third shape constraining device 746 is placed between the third end mechanism 720 and the access port 736. The third shape constraining device 746 helps reduce bending of the outer catheter 228 as it is inserted into the access port 736. The control system 703 can utilize any of the techniques described above to define an expected shape and determine whether shape data from the medical tool 724, the inner catheter 726, or the outer catheter 728 has exceeded that defined shape. In some examples, the outer catheter 728 can serve as a shape constraining device for the inner catheter 726, and the inner catheter 726 can serve as a shape constraining device for the tool 724. Although flexible, the catheters 726, 728 can be sufficiently rigid to provide support for devices extending therethrough.

[0092] One or more elements in embodiments of the application can be implemented in software to execute on a processor of a computer system, such as the control system 112. When implemented in software, the elements of the embodiments of the application are essentially the code segments to perform the necessary tasks. The program or code segments can be stored in a non-transitory processor-readable storage medium or device, including any medium that can store information including an optical medium, semiconductor medium, and magnetic medium. Processor-readable storage device examples include an electronic circuit; a semiconductor device, a semiconductor memory device, read-only memory (ROM), flash memory, erasable programmable read-only memory (EPROM); a floppy diskette, a CD-ROM, an optical disk, a hard disk, or other storage devices. The code segments can be downloaded via computer networks such as the Internet, Intranet, etc.

[0093] Note that the processes and displays presented can not inherently be related to any particular computer or other apparatus. The required structure for a variety of these systems will appear as elements in the claims. In addition, the embodiments are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages can be used to implement the teachings of the application as described herein.

[0094] While certain example embodiments of the application have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely exemplary of the application and are not to be considered as limiting the application, and that within the scope of the appended claims, various modifications can be made to the embodiments described and shown herein.

Claims

1. A system for detecting instrument bending, comprising: Instrument drive system; A slender, flexible instrument connected to the instrument drive system; One or more sensors associated with the elongated flexible device; as well as The control system is configured as follows: The slender, flexible instrument is propelled by the instrument drive system; During the advancement of the slender flexible instrument, the distance between two points on the slender flexible instrument is measured in the segment of the slender flexible instrument located between the instrument drive system and the anatomical entry channel. Compare the measured distance with the expected distance; as well as Determine whether the difference between the measured distance and the expected distance reaches a predefined threshold, wherein the difference between the measured distance and the expected distance reaching the predefined threshold indicates the bending of the slender flexible device.

2. The system according to claim 1, further comprising: A shape constraint mechanism is positioned to constrain the elongated flexible instrument at the segment between the instrument drive system and the anatomical entry channel.

3. The system of claim 2, wherein the control system is further configured to modify the shape of the shape constraint mechanism in response to determining that the difference between the measured distance and the expected distance reaches the predefined threshold.

4. The system of claim 1, wherein the control system is further configured to provide a notification in response to determining that the difference between the measured distance and the expected distance reaches the predefined threshold.

5. The system of claim 1, wherein the control system is further configured to place the elongated flexible instrument in a safe state in response to determining that the difference between the measured distance and the expected distance reaches the predefined threshold.

6. The system of claim 1, wherein the control system is further configured to automatically retract the elongated flexible instrument in response to determining that the difference between the measured distance and the expected distance reaches the predefined threshold, until the measured distance is within the predefined threshold of the expected distance.

7. The system of claim 1, wherein the expected distance is the minimum length of the segment of the elongated flexible instrument between the instrument drive system and the anatomical entry channel.

8. The system of claim 7, wherein the minimum length changes in real time as the elongated flexible instrument enters or retracts from the anatomical inlet channel.

9. The system of claim 7, wherein the location of the anatomical entry channel is determined by detecting the entry port using the one or more sensors.

10. The system of claim 7, wherein the insertion sensor of the instrument drive system is used to determine the position of the proximal end of the elongated flexible instrument relative to the instrument drive system.

11. The system of claim 10, wherein the insertion sensor comprises an electromagnetic sensor.

12. The system of claim 10, wherein the insertion sensor comprises an encoder sensor.

13. The system of claim 10, wherein the control system is further configured to determine the expected distance by subtracting the insertion distance measured by the insertion sensor from an initial distance between the proximal end of the elongated flexible instrument and the anatomical entry channel.

14. The system of claim 1, wherein the one or more sensors include fiber optic shape sensors, and the distance between the two points is measured using shape data from the fiber optic shape sensors.

15. The system of claim 1, wherein the one or more sensors include a position sensor.

16. The system of claim 15, wherein the position sensor comprises an electromagnetic sensor.

17. The system of claim 1, wherein the control system is further configured to increase the predefined threshold based on known or detected conditions.

18. The system of claim 17, wherein the known or detected condition includes friction within the anatomical channel.

19. The system of claim 17, wherein the known or detected condition includes obstruction or tortuous path in the anatomical channel.

20. The system of claim 17, wherein the known or detected condition includes the input force of the instrument drive system.

21. The system of claim 17, wherein the known or detected condition includes a sufficiently curved shape of the elongated flexible instrument within the patient's anatomy.

22. The system of claim 17, wherein the known or detected situation includes a planned navigation path predicted as tortuous.

23. A system for detecting instrument bending, comprising: Instrument drive system; A slender, flexible instrument connected to the instrument drive system; A shape sensor that extends through the elongated flexible device; as well as The control system is configured as follows: Identify the segments of the elongated, flexible instrument located outside the patient's anatomy; The shape sensor is used to measure the shape of the segment of the elongated flexible device; Compare the measured shape with the expected shape; as well as Determine whether the difference between the measured shape and the expected shape reaches a predefined threshold, wherein the difference between the measured shape and the expected shape reaching the predefined threshold indicates the bending of the slender flexible device.

24. The system of claim 23, wherein determining the segment of the elongated flexible instrument located outside the patient's anatomy comprises identifying the distal end of the segment based on a perturbation in shape data from the shape sensor.

25. The system of claim 24, wherein the disturbance is caused by the ingress port.

26. The system of claim 23, wherein determining the segment of the elongated flexible instrument located outside the patient's anatomy comprises identifying the distal end of the segment based on temperature changes along the elongated flexible instrument.

27. The system of claim 23, wherein identifying the segment of the elongated flexible instrument located outside the patient's anatomy comprises identifying the distal end of the segment based on measurements from an insertion sensor from the instrument drive system.

28. A system for detecting instrument bending, comprising: Instrument drive system; An elongated flexible instrument connected to the instrument drive system, the elongated flexible instrument including a shape sensor; as well as The control system is configured as follows: The slender, flexible instrument is advanced along the insertion direction using the instrument drive system; As the elongated flexible instrument is advanced, the shape of the proximal segment of the elongated flexible instrument is measured; Determine that a portion of the proximal segment of the elongated flexible instrument moves in a direction orthogonal to the insertion direction; as well as Based on the determination that the portion moves in a direction orthogonal to the insertion direction, a bending relief action is triggered.

29. The system of claim 28, wherein the bending relief action is triggered when the portion moves a predetermined distance in a direction orthogonal to the insertion direction.

30. The system of claim 28, wherein the bending relief action is triggered when the portion moves in a direction orthogonal to the insertion direction for a predetermined time.

31. A system for detecting instrument bending, comprising: catheter; An elongated flexible device configured to extend through the catheter, the elongated flexible device including a shape sensor; as well as The control system is configured as follows: The shape sensor is used to measure the shape of the segment of the elongated flexible device in the catheter; Compare the measured shape with the expected shape; as well as Determine whether the difference between the measured shape and the expected shape reaches a predefined threshold, wherein the difference between the measured shape and the expected shape reaching the predefined threshold indicates the bending of the slender flexible device.

32. The system of claim 31, wherein the desired shape is based on the shape of the catheter.

33. The system of claim 31, wherein the elongated flexible instrument includes a second catheter.

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