Nested robotic systems having load monitoring

Abstract

Methods and apparatuses for detecting a load on a patient from a robotic apparatus and particularly dynamically rigidizing robotic apparatuses, to prevent harm and discomfort to the patient. In particular, these methods and apparatuses may determine the load(s) between the inserted robotic member(s) from the proximal end of the inserted members (e.g., the drive sub-assembly) and may provide output including, but not limited to, one or more alerts to the user, and / or may alter the operation of the apparatus base on the determined load(s). These methods and apparatuses may use sensing inputs from the proximal end of the inserted members as well as the rigidity state of the members to determine patient loads in real time.

Description

NESTED ROBOTIC SYSTEMS HAVING LOAD MONITORINGCLAIM OF PRIORITY

[0001] This patent application claims priority to U.S. provisional patent application no. 63 / 710,010, titled “NESTED ROBOTIC SYSTEMS HAVING CONTINUOUS FORCE MONITORING,” and fried on October 21, 2024, herein incorporated by reference in its entirety.BACKGROUND

[0002] An experienced user, such as a doctor, surgeon, or other clinician, may control the operation of a scope, such as but not limited to, a colonoscope, based on the feel of the scope as it is inserted or withdrawn. For example, conventional colonoscopy procedures using a manual colonoscope rely greatly on the user’s tactile feedback to estimate insertion or retraction forces. A colonoscope is typically a flexible tube that can be steered through the curves and bends of the GI tract. As the doctor advances the scope, they receive tactile feedback (through the handle or scope controls) in the form of resistance or pressure. This feedback helps them determine if the scope is encountering a bend, obstruction, or narrowing in the colon. The walls of the colon are delicate, and too much force can cause injury. Tactile feedback allows the doctor to sense when the scope is applying too much pressure on the colon wall, helping them adjust their technique to avoid perforation or other injuries. Tactile feedback may also help the doctor recognize looping and adjust the scope’s position to straighten it out and prevent discomfort or injury to the patient. In general, tactile feedback allows the doctor to feel resistance, pressure, or changes in texture while navigating the colonoscope, providing important cues to effectively perform the procedure.

[0003] Recently robotic systems for advancing an endoscope have been developed, which may offer many significant advantages over manual scopes, including manual colonoscopes. For example, U.S. patent 11,724,065, “NESTED RIGIDIZING DEVICES,” describes nested and rigidizing robotic systems that may access regions deep within the body, such as the colon. However, such robotically controlled systems may not provide direct tactile feedback to the user. Although such devices have been shown to be safer than even generally used endoscopes, it would be beneficial to provide methods and apparatuses for such robotic systems, and particularly but not exclusively for nested and rigidizing robotic systems, that may provide continuous and effective estimation of the loads and / or torque (e.g., the force at the distal end region of the robotic system) to prevent or limit large forces acting on thepatient in both normal and faulted conditions. Described herein are methods and apparatuses that may address these needs.SUMMARY OF THE DISCLOSURE

[0004] Described herein are methods and apparatuses, including devices and systems, that monitor force and / or load sensing, in real time, to provide a user direct and reliable feedback during use in order to prevent or limit patient loads and may help guide a user (e.g., doctor, surgeon, technician, etc.) or an automated or semi-automated system in controlling the force applied by the nested robot. This may be particularly helpful in robotic systems that may have less immediate haptic feedback to the user. Thus, described herein are apparatuses, e.g., systems, devices, etc., including software, hardware and firmware, including in particular nested, rigidizing robotic systems that are configured to infer or otherwise determine the force acting on the distal end region of the apparatus (e.g., the inner member and / or outer member) based primarily on input from the proximal end region of the apparatus (e.g., handle). This information may be presented to the user during operation of the apparatus and / or may modify the operation of the apparatus to prevent or reduce harm to the patient.

[0005] In some cases, these method and apparatuses may describe a system including proximal force and / or load sensing for determining the forces and / or loads acting along the length and / or at the distal end region of the apparatus, including at one or both of the inner and outer nested rigidizing members. These apparatuses may be configured to sense force and / or load regardless of the operational state of the inner and / or outer members, and / or even during one or more failure modes of the apparatus. Thus, described herein are apparatuses including a plurality of sensors at the proximal end that are arranged to provide estimates of force load(s) on the inner and / or outer elongate members of a nested rigidizing robot. These methods and apparatuses may include one or more subsystems for inferring the force and / or load on the inner and / or outer nested elongate members and determining if the inferred force and / or load is within an expected (e g., safe) range during operation in all operational configurations and combinations of configurations or states, including but not limited to advancing / retracting, steering, rigidizing.

[0006] The methods and apparatuses described herein, including techniques for identifying and / or limiting the force / load applied to a patient, may be based on the identification of a plurality of different “states” of the nested pair of members, and in particular rigidizing members. In general, these state may depend on the status of the inner and outer nested members (rigid, non-rigid, relative position, etc.) and may be based on theforces applied to each. Although it may be possible to provide a reference (e.g., look-up table) with appropriate forces listed for one or more different thresholds of force on the inner and / or outer members during operation, as described herein, in some cases a simplified yet highly accurate technique has been invented that may use a reduced number of inputs needed to provide an accurate estimate of force load and / or turning force (e.g., torque) on the patient.

[0007] In general, these methods and apparatuses may refer to forces and / or loads. In some cases a load may refer to the force that is exerted on a patient’s body, which may be considered as resistance. Force may be considered a general term, while load may be used to describe the external forces acting on a system. As used herein, both force and load may be measured in units of Newtons (N) or pounds-force (Ibf). Thus, as used herein load and force may be used interchangeably, unless the context specifies otherwise.

[0008] The methods and apparatuses described herein may be part of any robotic system, including but not limited to systems for performing colonoscopy.

[0009] Aspects of the present disclosure may be integrated into a robotically-enabled medical system capable of performing a variety of medical procedures, including both minimally invasive procedures, such as laparoscopy, and non-invasive procedures, such as endoscopy. Among endoscopy procedures, the system may be capable of performing colonoscopy, enteroscopy, bronchoscopy, ureteroscopy, gastroscopy, etc. Examples of endoscopes may include, but are not limited to colonoscopes, arthroscopes, bronchoscopes, cystoscopes, hysteroscope, enteroscopes, esophagogastroduodenoscopes, hysteroscopes, neuroendoscopes, sinuscopes, laparoscopes, laryngoscopes, mediastinoscopes, sigmoidoscopes, nasopharyngoscopes, thoracoscopes, ureteroscopes, etc. Any of these scopes may be part of the nested, rigidizing systems.

[0010] Any of these apparatuses and methods may include an outer member (e.g., overtube), and an inner member (e.g., scope, such as, but not limited to an endoscope) and the inner member may be rigidizing or may include or be used with a rigidizing shield, or sheath.

[0011] Any of the methods and apparatuses described herein may be configured to estimate the force (e g. load) acting on the body by a nested pair of rigidizing members, such as (but not limited to) a nested rigidizing overtube and an endoscope assembly. The endoscope assembly may include a shield (or sheath, including a rigidizing shield as described in PCTUS2025020479, titled “RIGIDIZING ENDOSCOPE SHIELD,” herein incorporated by reference in its entirety) attached over and / or within an endoscope. Either or both the overtube and endoscope (e.g., endoscope assembly) may be rigidizing.

[0012] As mentioned, the nested robotic apparatus may include a rigidizing endoscope (e.g., endoscope assembly) nested within a rigidizing overtube. Any of these methods andapparatuses may advantageously determine an approximate estimate of the force / load acting at the distal end (and / or along the length) of the nested robotic apparatus relative to a body into which the nested robotic apparatus is inserted.. Advantageoulsy, this load on the patient, which may refer to the insertion force and / or load (e.g., force / load) on the patient or the insertion force / load on the body region within the patient interacting with the nested robotic apparatus may be estimated based on force / load measurements taken from a proximal end of the robotic apparatus, e.g., outside of the patient.

[0013] In general, the force / load may be estimated based on at least: the insertion force / load of the overtube, the insertion force / load of the endoscope (e.g., endoscope assembly), the net insertion force / load, and the rigidization state of either or both rigidizing members that are nested together and inserted into the body (e g., overtube and / or endoscope assembly). The rigidization state may be a determination that the rigidizing member is rigid or flexible (e.g., one of two states). This determination may be based on the robotic apparatus controlling a positive and / or negative pressure within the endoscope and / or overtube to transition the endoscope and / or overtube between a more rigid state and a more flexible state.

[0014] Thus, any of the methods and apparatuses described herein may include one or more force and / or load sensors that engage with the proximal end region of the nested robotic apparatus, including by connecting to a mount or mounts that drive insertion, withdrawal and / or steering of the nested robotic apparatus into or out of the patient, either together or relative to each other, such as moving the inner member (endoscope assembly) relative to the outer member (e g., overtube). In general, any of these systems may include a sensor for estimating or measuring insertion force / load of the outer member by connecting to the mount for the outer member, and / or a sensor for estimating or measuring force / load of the inner member by connecting to a mount for the inner member. In some examples, one of these sensors may be configured to measure a net force / load between insertion force / load of the inner and outer members directly. In some examples, the net force / load may be derived from the insertion forces / loads of the nested first (e.g., outer) and second (e.g., inner) members. For example, separate force / load sensors may be used for sensing insertion force / load on the first member, insertion force / load on the second member, and net insertion force / load.Alternatively, one force / load sensor may measure net force / load and while another force / load sensor measures the insertion force / load for the first member and the insertion force / load for the second member may be derived from the net force / load and the insertion force / load for the first member. Alternatively, a force / load sensor may measure net force / load and while another force / load sensor measures the insertion force / load for the second member and the insertion force / load for the first member may be derived from the net force / load and theinsertion force / load for the first member. Redundant insertion force / load sensors may be used and may be arranged in series or in parallel.

[0015] Any of the apparatuses and methods described herein may be configured to perform a method including at least the steps of: receiving or determining an insertion force and / or load for a first rigi dizing member of a nested robotic apparatus; receiving or determining an insertion force and / or load for a second rigidizing member of the nested robotic apparatus; receiving or determining a rigidization status of the first rigidizing member; receiving or determining a rigidization status of the second rigidizing member; determining a force and / or load on a patient for the nested robotic apparatus based on at least: the insertion force and / or load for the first rigidizing member, the insertion force and / or load for the second rigidizing member, a net insertion force and / or load for the first and second rigidizing members, the rigidization status of the first rigidizing member and the rigidization status of the second rigidizing member; and providing an output based on the determined force and / or load on the patient.

[0016] Described in greater detail herein are methods and apparatuses that may accurately estimate the force from a set of nested rigidizing elongate members (e.g., overtube and endoscope assembly) that are inserted into a patient’s body based on the rigidization status and force / load sensed for each rigidizing elongate member outside of the body, e.g., at the attachment between the rigidizing elongate members and the robot. The robot is generally configured for insertion and withdrawal of both the first and second rigidizing elongate members and individual insertion and withdrawal of at least one of the first and second rigidizing elongate members (but preferably both the first and second elongate rigidizing members).

[0017] The relationship between the rigidization state of the nested first and second rigidizing elongate members and the insertion force / load for each of the first and second elongate rigidizing members may be provide a remarkably accurate and comprehensive description of the force / load acting on the body (or region of the body) into which the nested rigidizing elongate members are inserted. In general, the force / load acting on the patient may be determined or derived from these inputs; for example, if the overtube is rigid and the endoscope is rigid and the endoscope insertion force / load is the same sign as the sign of the overtube insertion force / load (and in some cases, if the endoscope is not retroflexing) then the force acting on the body is approximately equal to the higher of either the overtube insertion force / load and the endoscope insertion force / load. Otherwise the force / load acting on the patient is approximately the same as the net value of the overtube insertion force / load and the endoscope insertion force / load.

[0018] For example, determining the force and / or load on the patient may comprise setting the force and / or load on the patient to a larger of the force and / or load for the first rigidizing member and the force and / or load for a second rigidizing member if both the first and second rigidizing members are in a rigid configuration and if a sign of the force and / or load for the first rigidizing member is the same as a sign of the force and / or load for a second rigidizing member, otherwise setting the force and / or load on the patient to the net insertion force and / or load from both the first and second elongate members.

[0019] Although the methods and apparatuses described herein typically relate to insertion force / load, the same techniques may be used, separately or concurrently, to determine rotational (torque) force / load.

[0020] In any of these methods and apparatuses, receiving or determining the insertion force and / or load for the first rigidizing member may comprise receiving the insertion force and / or load for an overtube of the nested robotic apparatus. In any of these methods and apparatuses, receiving or determining the insertion force and / or load for the first rigidizing member may comprise receiving the insertion force and / or load from a first force and / or load sensor coupled between a first mount to which the first rigidizing member is coupled and a link assembly. In any of these methods and apparatuses, receiving or determining the insertion force and / or load for the second rigidizing member may comprise receiving the insertion force and / or load for an endoscope of the nested robotic apparatus. In any of these methods and apparatuses, receiving or determining the insertion force and / or load for the second rigidizing member may comprise receiving the insertion force and / or load from a second force and / or load sensor coupled between a second mount to which the second member is coupled and a link assembly. In any of these methods and apparatuses, receiving or determining the rigidization status of the first rigidizing member may comprise determining the rigidization status based on a pressure applied to rigidize the first rigidizing member.

[0021] In general, the pressure applied (e.g., to rigidize the first elongate rigidizing member, or the second elongate rigidizing member) may be positive and / or negative pressure. In some cases the first elongate rigidizing member may be converted form a more flexible configuration to a more rigid configuration by the application of positive pressure (e.g., between about 1.5-8 atmospheres). In some cases the first elongate rigidizing member may be converted form a more flexible configuration to a more rigid configuration by the application of negative pressure. In some cases, pressure may also be applied (negative or positive pressure) to convert (or assist in converting) from a more rigid configuration to a more flexible configuration. The first and second rigidizing elongate members may independentlyrigidized / de-rigidized. The first rigidizing elongate member may be rigidized by the application of negative pressure and the second rigidizing elongate member may be rigidized by the application of positive pressure, or vice-versa.

[0022] Any of these methods and apparatuses may include using a retroflexion indicator to indicate when the nested apparatus (e.g., the first and / or second elongate rigidizing members) are retroflexed, e.g., bent to an angle of 135 degrees or more (e.g., 140 degrees or more, 150 degrees or more, 160 degrees or more, 170 degrees or more, 175 degrees or more 180 degrees or more, etc.). A retroflexion indicator may be a Boolean indicator (e.g., similar, in some examples, to the rigidization state) indicating if either or both the first and second rigidizing elongate members are retroflexed (yes / no). The retroflexion indicator may be used as part of the technique for determining if the force / load acting on the body or both region is the net force between the insertion force of the first and second elongate members, or a net insertion force. For example, determining the force and / or load on the patient (e.g., patient body or body region) for the nested robotic apparatus may include determining the force and / or load on the patient based on the retroflexion indicator indicating if the second rigidizing elongate member is or is not retroflexing by setting the force and / or load on the patient to a larger of the force and / or load for the first rigidizing member and the force and / or load for a second rigidizing member if both the first and second rigidizing members are in a rigid configuration and if a sign of the force and / or load for the first rigidizing member is the same as a sign of the force and / or load for a second rigidizing member and if the retroflexion indicator indicates that the second rigidizing elongate member is not retroflexing, otherwise setting the force and / or load on the patient to the net insertion force and / or load from both the first and second elongate members.

[0023] In any of the methods and apparatuses described herein, receiving or determining a rigidization status of the second rigidizing member may comprise determining the rigidization status based on a pressure applied to rigidize the second rigidizing member. Determining may comprise determining in real time.

[0024] In general, these methods and apparatuses may include emitting an alert as (or as part of) providing the output. For example, any of these methods and apparatuses may include emitting a series of alerts based on the magnitude of the determined force and / or load. The alert may be visible (displaying text, symbols, graphics, colors, etc. on a screen / display, illuminating one or more LEDs, etc.), audible (e.g., emitting a tone, alarm, etc ), and / or tactile (e.g., vibrating the control(s), providing resistance to advancing and / or withdrawing on the control(s), etc ). The intensity of the output may be scaled to the force / load, e.g., based onhow far beyond a threshold (e.g., outside of an operational / acceptable threshold or threshold range).

[0025] In any of these apparatuses and methods providing the output may include changing the operation of the apparatus, including stopping or slowing advancement, automatically or semi-automatically withdrawing, de-rigidizing, etc. For example, providing the output may comprise de-rigidizing the first and / or second rigidizing member.

[0026] Also described herein are apparatuses, including robotic apparatuses for operating nested first and second elongate rigidizing member (e.g., overtube and endoscope assembly). An apparatus may include: a first mount configured to couple to a first rigidizing elongate member; a second mount configured to couple to a second rigidizing elongate member that is nested with the first elongate member; a drive configured to linearly drive the second mount relative to the first mount; a first sensor coupled to the first mount and configured to sense a force and / or load from the first rigidizing elongate member; a second sensor coupled to the second mount and configured to sense a force and / or load from the rigidizing second elongate member; and a controller comprising one or more processors receiving input from the first sensor and the second sensor, wherein the controller is configured to determine a force and / or load on the patient based on: the force and / or load sensed by the first sensor, the force and / or load sensed by the second sensor, a net force and / or load from both the first and second elongate members, and a rigidization state of the first rigidizing elongate member and / or the second rigidizing elongate member, wherein the controller is configured to provide an output based on the determine load on the patient.

[0027] The first mount typically includes a surface to which a portion (e.g., handle, cartridge, etc.) of the first rigidizing elongate member (e.g., overtube) is secured, e.g., by engaging a coupler. The first mount may include interfaces for interfacing with one or more components (ports, drives, etc.) to control operation of the first rigidizing elongate member. For example the first mount may include a pressure interface for engaging with one or more pressure ports on the first rigidizing elongate member, a roll drive for driving roll between the first rigidizing elongate member and the mount, etc. Similarly the second mount typically includes a surface to which a portion (e g., handle, cartridge, etc.) of the second rigidizing elongate member (e.g., endoscope assembly, which may be in some examples an endoscope and a shield to cover the endoscope and / or rigidize the endoscope) is / are secured, e.g., by engaging one or more couplers. The second mount may include interfaces for interfacing with one or more components to control operation of the first rigidizing elongate member, such as a one or more tendon (steering) drives, pressure port(s), etc

[0028] The drive configured to linearly drive the second mount relative to the first mount may be a linear drive and may include an actuator, gearing, etc. Any of these apparatuses may also be configured to drive the first and second mounts (and therefore the first and second elongate rigidizing members) together for insertion / withdrawal. The joint movement of the first and second elongate rigidizing members may be controlled by a telescoping assembly (e.g., of links, arms, tubes, etc.) or a robotic arm. Thus the first and second elongate rigidizing members may be moved together or independently. Similarly, any of these apparatuses may be configured to control roll (and therefore generate torque) of the first and / or second elongate members individually or together.

[0029] In general, the controller may be configured to determine the force and / or load on the patient by setting the force and / or load on the patient to a larger of the force and / or load from the first sensor and the force and / or load from the second sensor if both the first and second rigidizing elongate members are in a rigid configuration and if a sign of the force and / or load from the first sensor is the same as a sign of the force and / or load from the second sensor, otherwise setting the force and / or load on the patient to the net force and / or load from both the first and second elongate members.

[0030] As mentioned, the controller may be configured to determine the force and / or load on the patient further based on an indicator indicating if the second rigidizing elongate member is or is not retroflexing. For example, the controller may be configured to determine the force and / or load on the patient by setting the force and / or load on the patient to a larger of the force and / or load from the first sensor and the force and / or load from the second sensor if both the first and second rigidizing elongate members are in a rigid configuration and if a sign of the force and / or load from the first sensor is the same as a sign of the force and / or load from the second sensor and if the indicator indicates that the second rigidizing elongate member is not retroflexing, otherwise setting the force and / or load on the patient to the net force and / or load from both the first and second elongate members.

[0031] In general, any of these apparatuses may be telescoping robots. In some cases the apparatus may include a plurality of telescoping links wherein the first mount and the second mount are each coupled to an outer link of the plurality of telescoping links. For example, the first sensor may be coupled between the first mount and to the outer link. The second sensor may be coupled between the second mount and the outer link. The first mount may be configured to couple to an overtube. The second mount may be configured to couple to an endoscope assembly (e.g., an endoscope or a shield and an endoscope).

[0032] The second mount may comprise one or more actuators for actuating one or more tendons to steer the second rigidizing elongate member. Any of these apparatuses mayinclude sensor (e.g., “net sensor”) that is configured to sense the net force and / or load from the first and second rigidizing elongate members. In some cases the net sensor comprises a local net sensor coupled at a first end to both the first mount and the second mount, and at an opposite end to an outer link to which both the first and second mounts are attached. The first or second sensor may comprises a net sensor configured to sense the net force and / or load from the first and second rigidizing elongate members.

[0033] Any of these apparatuses may include one or more pressures sensors configured to determine a pressure applied to the first and / or second elongate member. The controller may be configured to determine the rigidization state of the first and / or second member based on a positive or negative fluid pressure applied to the first and / or second member to rigidize the first and / or second members. For example, the controller may include or generate a first rigidization state indicator for the first elongate rigidizing member; the controller may include or generate a second rigidization state indicator for the second elongate rigidizing member. The rigidization state indicators may be Boolean (e g., rigid / flexible) indicators. In some cases the rigidization state indicator(s) may include a scaled value (e.g., reflecting how rigid or flexible the rigidizing member is). The rigidization state indicator may be referred to herein as a rigidization state flag. The rigidization state indicator may be a data structure that may reside in the controller (e.g., in a memory and / or processor of the controller).

[0034] The term elongate rigidizing member may also be referred to generally as a rigidizing member or as an elongate member. Unless the context indicates otherwise, these terms may be used interchangeably as any of the elongate members described herein may be configured as rigidizing members, such as overtubes and / or endoscope assemblies.

[0035] Any of these apparatuses may be configured to provide an output, such as an alert. In some cases the output may comprise a series of alerts based on the magnitude of the determined force and / or load. For example, the output may comprise a change in the rigidity of the first and / or second rigidizing elongate members. The output may include an indicator (e.g., visual, audible, tactile, etc.) as described above.

[0036] For example, an apparatus may include: a plurality of telescoping links; a first mount coupled to an outer link of the plurality of telescoping links, wherein the first mount is configured to couple to a first elongate member; a second mount coupled to the outer link, wherein the second mount is configured to couple to a second elongate member that is nested with the first elongate member and to linearly actuate relative to the outer link; a first force and / or load sensor coupled to the first mount and configured to sense a force and / or load from the first elongate member; a second force and / or load sensor coupled to the second mount and configured to sense a force and / or load from the second elongate member; and a controllercomprising one or more processors receiving input from the first force and / or load sensor and the second force and / or load sensor, wherein the controller is configured to determine a force and / or load on the patient based on: the force and / or load sensed by the first force and / or load sensor, the force and / or load sensed by the second force and / or load sensor, a net force and / or load from both the first and second elongate members, and a rigidization state of the first and / or second member, and to provide an output based on the determined force and / or load on the patient.

[0037] The controller may be configured to determine the force and / or load on the patient based on the higher of the force and / or load from the first force and / or load sensor and the second force and / or load sensor when both the first elongate member and the second elongate members are in a rigid configuration and when both the force and / or load from the first force and / or load sensor or the force and / or load from the second force and / or load sensor are the same sign. The first force and / or load sensor may be coupled to the first mount and to the outer link. The second force and / or load sensor may be coupled between the second mount and the outer link. The first mount may be configured to couple to an overtube. The second mount may be configured to couple to an endoscope. The second mount may comprise one or more actuators for actuating one or more tendons to steer the first elongate member.

[0038] Any of these apparatuses may include a net force and / or load sensor configured to sense a force and / or load from both the first and second elongate members. The net sensor may comprise a local net force and / or load sensor coupled at a first end to both the first mount and the second mount, and at an opposite end to the outer link.

[0039] In general, any of these apparatuses may be configured to determine the rigidization state(s) of the first and / or second elongate members. For example, the apparatus may include one or more pressures sensors configured to determine a pressure applied to the first and / or second elongate member. The controller may be configured to determine the rigidization state of the first and / or second member based on a positive or negative fluid pressure applied to the first and / or second member to rigidize the first and / or second members.

[0040] For example, an apparatus may include: a plurality of telescoping links; a first mount coupled to an outer link of the telescoping links, wherein the first mount is configured to couple to a first elongate member; a second mount coupled to the outer link of the telescoping links, wherein the second mount is configured to linearly actuate and to couple to a second elongate member that is nested with the first elongate member; a first force and / or load sensor coupled between the first mount and the outer link and configured to sense a force and / or load from the first elongate member; a second force and / or load sensor coupledbetween the second mount and the outer link and configured to sense a force and / or load from the second elongate member; a net force and / or load sensor configured to sense a load from both the first and second elongate members; and a controller comprising one or more processors receiving input from the first force and / or load sensor and the second force and / or load sensor, wherein the controller is configured to determine a force and / or load on the patient based on the force and / or load sensed by the first force and / or load sensor, the force and / or load sensed by the second force and / or load sensor, a net force and / or load from both the first and second elongate members, and a rigidization state of the first and / or second member and to provide an output based on the determine force and / or load on the patient.

[0041] Also described herein are methods including: receiving or determining an insertion force and / or load for a first member of a nested robotic apparatus; receiving or determining an insertion force and / or load for a second member of a nested robotic apparatus; receiving or determining a rigidization status of the first member; receiving or determining a rigidization status of the second member; determining a force and / or load on the patient for the nested robotic apparatus from the insertion force and / or load for the first member, the insertion force and / or load force and / or load for the second member, a net insertion force and / or load for the first and second members, the rigidization status of the first member and the rigidization status of the second member; and providing an output based on the determined force and / or load on the patient.

[0042] Determining the force and / or load on the patient may comprise setting the force and / or load on the patient to the higher of the insertion force and / or load for the first member or the insertion force and / or load for the second member when both the first member and the second member in a rigid configuration. In some cases determining the force and / or load on the patient comprises setting the force and / or load on the patient as the net insertion force and / or load when the first elongate member is in a flexible configuration and the second elongate member is in a flexible configuration or when the insertion force and / or load of the second elongate member has a different sign than a sign of the insertion force and / or load of the first elongate member. Receiving or determining the insertion force and / or load for the first member may comprise receiving the insertion force and / or load for an overtube of the nested robotic apparatus. Receiving or determining the insertion force and / or load for the first member may comprise receiving the insertion force and / or load from a first force and / or load sensor coupled between a first mount to which the first member is coupled and a link assembly. In some cases receiving or determining the insertion force and / or load for the second member comprises receiving the insertion load for an endoscope of the nested robotic apparatus. Receiving or determining the insertion force and / or load for the second membermay comprise receiving the insertion force and / or load from a second force and / or load sensor coupled between a second mount to which the second member is coupled and a link assembly. Receiving or determining the rigidization status of the first member may comprise determining the rigidization status based on a pressure applied to rigidize the first member. The pressure applied may be a positive and / or negative pressure. Receiving or determining a rigidization status of the second member may comprise determining the rigidization status based on a pressure applied to rigidize the second member.

[0043] In any of these methods or apparatuses determining may comprise determining in real (or near-real) time, e.g., at the same time or within a few minutes.

[0044] For example, a method as described herein may include: receiving or determining an insertion force and / or load for a first member of a nested robotic apparatus; receiving or determining an insertion force and / or load for a second member of a nested robotic apparatus; receiving or determining a rigidization status of the first member; receiving or determining a rigidization status of the second member; determining, in real time, a patient force and / or load for the nested robotic apparatus from the insertion force and / or load for the first member, the insertion force and / or load for eh second member, a net insertion force and / or load for the first and second members, the rigidization status of the first member and the rigidization status of the second member, by setting the force and / or load on the patient to the higher of the insertion force and / or load for the first member or the insertion force and / or load for the second member when both the first member and the second member in a rigid configuration and setting the force and / or load on the patient as the net insertion force and / or load when the first elongate member is in a flexible configuration and either the second elongate member is in a flexible configuration or the insertion force and / or load of the second elongate member has a different sign than a sign of the insertion force and / or load of the first elongate member; and providing an output based on the determine force and / or load on the patient.

[0045] In general, the methods described herein may be configured as methods of controlling and / or modifying operation of the robot (e.g., automatically or semi- automatically). These methods may include one or more additional steps for modifying the behavior of the robot based on the determined force and / or load on the patient for the nested robotic apparatus, such as (but not limited to) de-rigidizing, rigidizing, withdrawing one or both the first and second rigidizing elongate members, emitting a warning or alert, preventing or limiting further movement in a direction that would increase the force on the patient body or body region, etc.

[0046] Any of the methods described herein may be methods for displaying, in real or near-real time, an indicator of force and / or load on the patient for the nested roboticapparatus. For example, any of these methods may include updating a user interface to show an indicator of the force / load and / or a relative magnitude of the force / load on the patient body due to the first and / or second elongate rigidizing members in the body.

[0047] Any of the apparatuses described herein may include a user interface showing force / load as determined herein. These user interfaces may include a visible tool or widget for displaying the force and / or load on the patient for the nested robotic apparatus.

[0048] For example, described herein are apparatuses comprising: a link assembly; a first force and / or load sensor coupled to a first mount on an outer link of the link assembly and configured to sense an insertion force and / or load from a first elongate member of a nested robotic apparatus that is coupled to the first mount; a second force and / or load sensor coupled to a second mount on the outer link and configured to sense an insertion force and / or load from a second elongate member of the nested robotic apparatus that is coupled to the second mount; one or more processors; and a controller comprises one or more processors and a memory coupled to the one or more processors, the memory storing computer-program instructions, that, when executed by the one or more processors, perform a computer- implemented method comprising: determining a force and / or load on the patient for the nested robotic apparatus from the insertion force and / or load for the first member, the insertion force and / or load for the second member, a net insertion force and / or load for the first and second members, a rigidization status of the first member and a rigidization status of the second member; and providing an output based on the determined force and / or load on the patient.

[0049] Any of these apparatuses may include a plurality of telescoping links; a first mount coupled to an outer link of the plurality of telescoping links, wherein the first mount is configured to couple to a first elongate member; a second mount coupled to the outer link, wherein the second mount is configured to couple to a second elongate member that is nested with the first elongate member and to linearly actuate relative to the outer link; a first force sensor coupled to the first mount and configured to sense a load from the first elongate member; a second force sensor coupled to the second mount and configured to sense a load from the second elongate member; and a controller comprising one or more processors receiving input from the first force sensor and the second force sensor, wherein the controller is configured to determine a load on the patient based on: the load sensed by the first force sensor, the load sensed by the second force sensor, a net load from both the first and second elongate members, and a rigidization state of the first and / or second member, and to provide an output based on the determine load on the patient.

[0050] The controller may be configured to determine the load on the patient based on the higher of the load from the first force sensor or the load sensed by the second force sensor when both the first elongate member and the second elongate member in a rigid configuration. In some examples the controller is configured to determine the load on the net load of the load from the first force sensor and the load sensed by the second force sensor when the first elongate member is in a flexible configuration and either the second elongate member is in a flexible configuration or the second elongate member is in a rigid configuration but the signs of the load sensed by the first force sensor is different from the sign of the load sensed by the second force sensor.

[0051] The first force sensor may be coupled to the first mount and to the outer link. The second force sensor may be coupled between the second mount and the outer link. The first mount may be configured to couple to an overtube; the second mount may be configured to couple to an endoscope. The second mount may comprise one or more actuators for actuating one or more tendons to steer the first elongate member.

[0052] Any of these apparatuses may include a net force sensor configured to sense a load from both the first and second elongate members. The net sensor may comprise local net sensor coupled at a first end to both the first mount and the second mount, and at an opposite end to the outer link.

[0053] Any of these apparatuses may include one or more pressures sensors configured to determine a pressure applied to the first and / or second elongate member. The controller may be configured to determine the rigidization state of the first and / or second member based on a positive or negative fluid pressure applied to the first and / or second member to rigidize the first and / or second members.

[0054] The apparatuses may be configured to emit any appropriate output. For example, the output may comprises an alert. The output may comprise a series of alerts based on the magnitude of the determined load. The output may comprises a change in the rigidity of the first and / or second elongate member.

[0055] In some examples an apparatus may comprise: a plurality of telescoping links; a first mount coupled to an outer link of the telescoping links, wherein the first mount is configured to couple to a first elongate member; a second mount coupled to the outer link of the telescoping links, wherein the second mount is configured to linearly actuate and to couple to a second elongate member that is nested with the first elongate member; a first force sensor coupled between the first mount and the outer link and configured to sense a load from the first elongate member; a second force sensor coupled between the second mount and the outer link and configured to sense a load from the second elongate member; anet force sensor configured to sense a load from both the first and second elongate members; a controller comprising one or more processors receiving input from the first force sensor and the second force sensor, wherein the controller is configured to determine a load on the patient based on the load sensed by the first force sensor, the load sensed by the second force sensor, a net load from both the first and second elongate members, and a rigidization state of the first and / or second member and to provide an output based on the determine load on the patient.

[0056] Also described herein are methods (in addition to apparatuses for performing these methods). For example, a method may include: receiving or determining an insertion load for a first member of a nested robotic apparatus; receiving or determining an insertion load for a second member of a nested robotic apparatus; receiving or determining a rigidization status of the first member; receiving or determining a rigidization status of the second member; determining a load on the patient for the nested robotic apparatus from the insertion load for the first member, the insertion load for the second member, a net insertion load for the first and second members, the rigidization status of the first member and the rigidization status of the second member; and providing an output based on the determined load on the patient.

[0057] The load on the patient may be determined by setting the load on the patient to the higher of the insertion load for the first member or the insertion load for the second member when both the first member and the second member in a rigid configuration. In some cases determining the load on the patient comprises setting the load on the patient as the net insertion load when the first elongate member is in a flexible configuration and the second elongate member is in a flexible configuration or when the insertion load of the second elongate member has a different sign than a sign of the insertion load of the first elongate member.

[0058] In any of these methods or apparatuses, receiving or determining the insertion load for the first member may comprise receiving the insertion load for an overtube of the nested robotic apparatus. For example, receiving or determining the insertion load for the first member may comprise receiving the insertion load from a first force sensor coupled between a first mount to which the first member is coupled and a link assembly. Receiving or determining the insertion load for the second member may comprise receiving the insertion load for an endoscope of the nested robotic apparatus. In any of these methods, receiving or determining the insertion load for the second member may comprise receiving the insertion load from a second force sensor coupled between a second mount to which the second member is coupled and a link assembly. Receiving or determining the rigidization status ofthe first member may comprise determining the rigidization status based on a pressure applied to rigidize the first member.

[0059] The pressure applied may be a positive and / or negative pressure.

[0060] In any of these examples, receiving or determining a rigidization status of the second member may comprise determining the rigidization status based on a pressure applied to rigidize the second member. In any of these steps, determining may comprise determining in real time. Any of these methods may include providing the output comprises emitting an alert. Providing the output may comprise emitting a series of alerts based on the magnitude of the determined load. In some cases providing the output comprises de-rigi dizing the first and / or second elongate member.

[0061] For example, a method may include: receiving or determining an insertion load for a first member of a nested robotic apparatus; receiving or determining an insertion load for a second member of a nested robotic apparatus; receiving or determining a rigidization status of the first member; receiving or determining a rigidization status of the second member; determining, in real time, a patient load for the nested robotic apparatus from the insertion load for the first member, the insertion load for eh second member, a net insertion load for the first and second members, the rigidization status of the first member and the rigidization status of the second member, by setting the load on the patient to the higher of the insertion load for the first member or the insertion load for the second member when both the first member and the second member in a rigid configuration and setting the load on the patient as the net insertion load when the first elongate member is in a flexible configuration and either the second elongate member is in a flexible configuration or the insertion load of the second elongate member has a different sign than a sign of the insertion load of the first elongate member; and providing an output based on the determine load on the patient.

[0062] In general the apparatuses described herein may be robotic apparatuses for performing an endoscopic procedure (e g., colonoscopic, enteroscopic, bronchoscopic, ureteroscopic, gastroscopic, etc ). The robot may include a first sensor coupled to a first mount and configured to sense a force and / or load (e g., insertion force / load) from the first rigidizing elongate member, a second sensor coupled to a second mount and configured to sense a force and / or load (e g., insertion force / load) from the rigidizing second elongate member; and a controller configured to receive input from the first sensor and the second sensor, wherein the controller is configured to determine the insertion force and / or load on the patient based on the insertion force and / or load on the first elongate member, the force and / or load on the second elongate member, a net force and / or load from both the first and second elongatemembers, and a rigidization state of the first rigidizing elongate member and / or the second rigidizing elongate member, wherein the controller is configured to provide an output based on the determine load on the patient.

[0063] Any of these apparatuses may include: a link assembly; a first force sensor coupled to a first mount on an outer link of the link assembly and configured to sense an insertion load from a first elongate member of a nested robotic apparatus that is coupled to the first mount; a second force sensor coupled to a second mount on the outer link and configured to sense an insertion load from a second elongate member of the nested robotic apparatus that is coupled to the second mount; one or more processors; and a controller comprises one or more processors and a memory coupled to the one or more processors, the memory storing computer-program instructions, that, when executed by the one or more processors, perform a computer-implemented method comprising: determining a load on the patient for the nested robotic apparatus from the insertion load for the first member, the insertion load for the second member, a net insertion load for the first and second members, a rigidization status of the first member and a rigidization status of the second member; and providing an output based on the determined load on the patient.

[0064] As mentioned, any of these methods and apparatuses may be configured to estimate and / or respond to torque force(s) applied to the body by the rigidizing elongate members. For example, an apparatus may include: a first mount configured to couple to a first rigidizing elongate member; a second mount configured to couple to a second rigidizing elongate member that is nested with the first elongate member; a first rotational drive configured to rotate the first rigidizing elongate member; an optional second rotational drive configured to rotate the second rigidizing elongate member and / or to rotate both the first and second elongate rigidizing members; optionally the apparatus may include a drive configured to move the first rigidizing elongate member relative to the second elongate rigidizing member (e.g., by moving the mount). The apparatus may include a first torque sensor coupled to the first mount and configured to sense torque (e g., rotational force) from the first rigidizing elongate member; a second torque sensor coupled to the second mount and configured to sense a torque (e.g., rotational force) from the rigidizing second elongate member; and a controller comprising one or more processors receiving input from the first torque sensor and the second torque sensor, wherein the controller is configured to determine a torque (e.g., rotational force) on the patient due to the rotation of the nested rigidizing members, based on: the torque sensed by the first torque sensor, the torque sensed by the second torque sensor, a net torque from both the first and second elongate members, and a rigidization state of the first rigidizing elongate member and / or the second rigidizing elongatemember, wherein the controller is configured to provide an output based on the determine torque on the patient.

[0065] All of the methods and apparatuses described herein, in any combination, are herein contemplated and can be used to achieve the benefits as described herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0066] A better understanding of the features and advantages of the methods and apparatuses described herein will be obtained by reference to the following detailed description that sets forth illustrative embodiments, and the accompanying drawings of which:

[0067] FIGS. 1A-1D illustrate one example of an elongate medical instrument, such as a nested robotic scope device, that may be used with the methods and apparatuses described herein. The elongate medical instrument in this example is an endoscope (e.g., in some examples, a colonoscope) having a nested inner member and an outer member that are both selectively rigidizing.

[0068] FIG. 2A shows an example of a system for dispensing (e.g., deploying) and controlling a nested robotic device in a first configuration.

[0069] FIG. 2B shows the system for deploying and controlling a nested robotic device of FIG. 2A in a second configuration.

[0070] FIGS. 2C-2D show an example of a system similar to that shown in FIGS. 2A-2B including a rigidizing nested overtube and inner endoscope.

[0071] FIGS. 3 shows an example of a system as described herein to perform a lower-GI procedure.

[0072] FIG. 4A shows an example of a set of vertically arranged linear links for use with a drive sub-system for deploying a nested robotic device, including a first (e.g., overtube) linear driver and a second (e g., endoscope) linear driver on an inner linear link.

[0073] FIG. 4B shows the vertically arranged linear links of FIG. 4A with the second linear driver in a proximal position on the inner link.

[0074] FIG. 5 schematically illustrate one example of a pair of mounts and a link assembly of an apparatus as described herein including force sensors.

[0075] FIG. 6A shows an example of a schematic illustration of a first and second mount that may be coupled to a link assembly, illustrating insertion force / load sensors as described herein.

[0076] FIG. 6B is a schematic illustration of another example of a first and second mount that may be part of a robotic apparatus as described herein, showing examples of insertion force / load sensors that may be used.

[0077] FIG. 6C shows an example of a mount for a robot as described herein, illustrating torque sensing.

[0078] FIG. 7A shows an example of a force sensor comprising a strain gauge coupled to a first mount.

[0079] FIG. 7B shows the example of FIG. 7A with the link removed.

[0080] FIGS. 8A and 8B illustrate an example of a portion of a link assembly including a flexure configured as a force sensor.

[0081] FIGS. 9A-9B show an example of a mount assembly including a force sensor. FIG. 9B shows the example of FIG. 9A with the link show (as transparent).

[0082] FIGS. 10A-10B show an example of a net forces sensor that is configured to measure the net force on both the inner and outer members.

[0083] FIGS. 11A-11B illustrate an example of an outer link of a link assembly including a net force sensor. FIG. 1 IB shows the example of FIG. 11 A, but with the net force sensor removed.

[0084] FIG. 12 schematically illustrates an example of a local net force sensor configured so that the local net force sensor is mounted between a first (e.g., overtube) sensor and a second (e g., endoscope) sensor.

[0085] FIG. 13 is a simplified drawing of the local net force sensor shown in FIG. 12.

[0086] FIG. 14 illustrates an example of a local net force sensor mounted in-line in an outer link.

[0087] FIG. 15 schematically illustrates one example of a system configured to determine load on a patient as described herein.

[0088] FIG. 16 shows an example of free body diagrams schematically illustrating different operational conditions for the apparatus.

[0089] FIG. 17 schematically illustrates forces when the scope is sliding along tissue walls.

[0090] FIG. 18 schematically illustrates the stretching forces when the colonoscope is stuck on the tissue walls.

[0091] FIG. 19 is a graph showing an example of the load forces on the endoscope and overtube.

[0092] FIG. 20 is a graph showing an example of force loads acting on a nested system as described herein.

[0093] FIG. 21 is a diagram illustrating the forces acting at the distal end region of a nested pair of rigidizing members as the tip of the endoscope gets wedged around a corner or flexure.

[0094] FIG. 22 shows a diagram illustrating the forces acting at the distal end region of a nested pair of rigidizing members when the flexible proximal body of the nested pair is pushed around a bend in the colon.

[0095] FIG. 23 is a diagram illustrating the forces acting at the distal end region of a nested pair of rigidizing members similar to FIG. 21 but showing the lateral load.

[0096] FIG. 24 shows a diagram illustrating the forces acting at the distal end region of a nested pair of rigidizing members when the endoscope is being steered (e.g., bent).

[0097] FIG. 25 shows a diagram illustrating the forces acting at the distal end region of a nested pair of rigidizing members when it pushes around the colon walls while steering around bend.

[0098] FIG. 26 shows a diagram illustrating the forces acting at the distal end region of a nested pair of rigidizing members when the bending section is not fully exposed from the overtube, and there are loads on that section along the device.

[0099] FIG. 27 shows a diagram illustrating the forces acting at the distal end region of a nested pair of rigidizing members when the apparatus is hooked around a bend and continuing to pull the devices back.

[0100] FIG. 28 illustrates an endoscope that was deliberately hooked around a flexure and withdrawn until the flexure seemed to be stretched, as well as graph so showing the relative position and force of the endoscope and overtube, including forces measured.

[0101] FIG. 29 shows a diagram illustrating the forces acting at the distal end region of a nested pair of rigidizing members when the flexible proximal body of the nested pair is pushed around a bend in the colon.

[0102] FIG. 30 shows a diagram illustrating the forces acting at the distal end region of a nested pair of rigidizing members when withdrawing the apparatus.

[0103] FIG. 31 shows a diagram illustrating the forces acting at the distal end region of a nested pair of rigidizing members when the overtube and / or endoscope are being torqued.

[0104] FIG. 32 is a graph of forces from the endoscope and overtube of one example of the apparatus.

[0105] FIG. 33 is another graph showing the effect of torque measures by the endoscope on the apparatus.

[0106] FIG. 34 shows a diagram illustrating the forces acting at the distal end region of a nested pair of rigidizing members during a retroflex maneuver.

[0107] FIGS. 35A-35B show examples of sliding of the robot illustrating the forces acting at the distal end region of a nested pair of rigidizing members.

[0108] FIG. 36A shows a set of graphs illustrating the forces acting at the distal end region of a nested pair of rigidizing members. FIG. 36B includes three graphs illustrating forces acting on the apparatus (endoscope, overtube, net) in the various configurations described herein.

[0109] FIG. 37A shows a set of graphs illustrating the forces acting at the distal end region of a nested pair of rigidizing members. FIG. 3 B includes three graphs illustrating forces acting on the apparatus (endoscope, overtube, net) in the various configurations described herein.

[0110] FIG. 38A shows a set of graphs illustrating the forces acting at the distal end region of a nested pair of rigidizing members. FIG. 38B includes three graphs illustrating forces acting on the apparatus (endoscope, overtube, net) in the various configurations described herein.[OHl] FIG. 39A shows a set of graphs illustrating the forces acting at the distal end region of a nested pair of rigidizing members. FIG. 39B includes three graphs illustrating forces acting on the apparatus (endoscope, overtube, net) in the various configurations described herein.

[0112] FIG. 40 A shows a set of graphs illustrating the forces acting at the distal end region of a nested pair of rigidizing members. FIG. 40B includes three graphs illustrating forces acting on the apparatus (endoscope, overtube, net) in the various configurations described herein.

[0113] FIG. 41 shows an example of how the frictional load from the overtube may either add to the false positive or detract from how well the robot can detect the loads on the endoscope.

[0114] FIG. 42 schematically illustrates how an exemplary friction acts in the opposite direction on the endoscope.

[0115] FIG. 43 shows all 8 possible loading and motion scenarios the system can be in when the endoscope is flexible and the overtube is rigid.

[0116] FIG. 44 illustrates examples of the loads detected by the endoscope in each of the 8 situations shown in FIG. 43.

[0117] FIG. 45 illustrates schematically an example of when spring can be applied in the same direction as the motion of a device as described herein.

[0118] FIG. 46 is a force diagram schematically illustrating a static equilibrium .

[0119] FIG. 47 is another example of a force diagram showing forces acting on an apparatus with and the derived body forces.

[0120] FIG. 48 illustrates the equations that may be used to interpret the loads acting on the body.

[0121] FIG. 49 shows another example of a force diagram showing forces acting on an apparatus with and the derived body forces.

[0122] FIG. 50 shows another example of a force diagram showing forces acting on an apparatus with and the derived body forces.

[0123] FIG. 51 illustrates the equations that may be used to interpret the loads acting on the body.

[0124] FIG. 52 shows another example of a force diagram showing forces acting on an apparatus with and the derived body forces.

[0125] FIG. 53 schematically illustrates one example of how the loads on the colon are distributed.

[0126] FIG. 54 shows a force diagram illustrating retroflexing.

[0127] FIGS. 55A-55B shows a force diagram illustrating a sweeping maneuver with a nested rigi dizing apparatus.

[0128] FIG. 56A-56B shows a force diagram illustrating holding the tip position with a nested rigi dizing apparatus.

[0129] FIG. 57A-57B shows a force diagram illustrating furling and unfurling with a nested rigi dizing apparatus.

[0130] FIG. 58 shows another force diagram for retroflexing and describing forces acting on the apparatus.

[0131] FIGS. 59A-59C show results from testing an arc movement on a nested apparatus as described herein.

[0132] FIG. 60 is a graph showing manual retroflexing of a colonoscope.

[0133] FIGS. 61A-61B are graphs showing force when getting out of retroflexing using a nested apparatus as described herein

[0134] FIG. 62 illustrates an example of a graph showing manual colonoscope operation forces.

[0135] FIG. 63 is a force diagram for torquing as described herein

[0136] FIG. 64 is a graph showing the torque from the endoscope and overtube.

[0137] FIG. 65A-65B show examples of loads (from load diagrams) at the tip are fully transmitted back to the insertion point.

[0138] FIG. 66 is a force diagram illustrating the situation where a full support to the flexible overtube, allowing it to stretch out, is simplified.

[0139] FIG. 67 is a force diagram, showing stretching out and pushing up on the distal end region of an apparatus.

[0140] FIG. 68 includes force diagrams and graphs showing high frictional loads between the two devices (e.g., overtube and endoscope) of a nested apparatus.

[0141] FIGS. 69A-69B are graphs showing forces (acting on the components of the nested apparatus when moved through an N-loop (FIG. 69A) or an alpha loop (FIG. 69B).

[0142] FIG. 70 shows an example of force diagrams and related equations including the friction components.

[0143] FIG. 71 illustrates a force diagram, experimental setup, and loads on a nested apparatus created while the apparatus was shape copying.

[0144] FIG. 72 illustrates a force diagram, experimental setup, and loads on a nested apparatus created while the apparatus was loaded at the tip.

[0145] FIG. 73 illustrates force diagrams and example graphs showing the forces on the component parts (endoscope, overtube) during various movements.

[0146] FIG. 74 shows an example of the force diagram and forces (including frictional component between the two devices of the apparatus) during insertion.

[0147] FIG. 75 shows an example of the force diagram and forces (including frictional component between the two devices of the apparatus) during operation.

[0148] FIG. 76 shows an example of the force diagram and forces (including frictional component between the two devices of the apparatus) during operation.

[0149]

[0150] FIG. 77 shows an example of the force diagram and forces (including frictional component between the two devices of the apparatus) during operation.

[0151] FIG. 78 illustrates the 8 possible loading and motion scenarios the system can be in when the overtube is flexible and the endoscope is rigid.

[0152] FIG. 79 shows a subset of these loading and motion scenarios in greater detail.

[0153] FIG. 80 schematically illustrates one example of a series of increasingly-serious alerts (shown as a visual indicator).

[0154] FIG. 81 illustrates one example of a user interface as described herein.

[0155] FIG. 82 is a graph showing loads during a manual intubation during using the robot as described herein.

[0156] FIGS. 83A-83B are graphs showing loads during a robotic intubation.

[0157] FIG. 84 is a bar graph showing the percentage of time spent above a load threshold comparing manual and robotic procedures.

[0158] FIGS. 85A-85B illustrate an example of graphs showing loads for a manual navigation (FIG. 85A) versus robotic navigation (FIG. 85B).

[0159] FIG. 86A-86B shows an example of a patient force plot during a typical robotic navigation.

[0160] FIG. 87A-87C illustrate one example of a method of optimizing the threshold levels described herein.

[0161] FIG. 88A schematically illustrates an example of a method (or apparatus configured to perform the method) for estimating force / load on a patient from the force of the first member (e.g., overtube) and second member (e.g., endoscope) and the rigidization state of both.

[0162] FIG. 88B schematically illustrates an example of a method (or apparatus configured to perform the method) for estimating force / load on a patient from the force of the first member (e.g., overtube) and second member (e.g., endoscope), the rigidization state of both, and a retroflexion state of either or both the first and second members.

[0163] FIG. 89 schematically illustrates one example of an apparatus as described herein configured to perform a colonoscopy.

[0164] FIG. 90 schematically illustrates an example of an apparatus configured for use in a patient’s cardiovascular system.

[0165] FIG. 91 schematically illustrates an example of an apparatus configured for use within a patient’s neurovascular system.DETAILED DESCRIPTION

[0166] Inserting an apparatus into the body creates insertion forces on the body. Manual devices have known force profiles. However, navigating a manual colonoscope may result in insertion forces on the colon walls and stretching of the mesentery, leading to bleeding, discomfort, or perforations. With manual endoscopes, physicians limit how much force they use to push or roll the endoscope using tactile feedback while navigating to prevent or lessen these effects. Robotic systems have the potential to offer lower force profiles but may provide less immediate user feedback Robotic systems are typically controlled using a user input device controller rather than directly holding the scope in their hand and therefore, may lack tactile feedback. The loss of tactile feedback has the potential to be of concern for the patient, including during insertion (e.g., intubation) and withdrawal.

[0167] In the methods and apparatuses described herein, robotic apparatuses inserted into the body may dynamically control the flexibility (e.g., rigidity) of the inserted elongate member (e.g., a rigidizing assembly) during operation of the apparatus. Such dynamically rigi dizing apparatuses have many advantages, including improved ease of learning, multiple ergonomic advantages, the ability to navigate through highly tortious anatomy as well as providing a stable and supported platform for imaging, diagnosis and treatment within the body. However, dynamic rigidization may make estimating the force and / or load on the body more difficult, as the system performance varies with their flexibility / rigidity.

[0168] The methods and apparatuses, e.g., devices and systems, including software, hardware and / or firmware, described herein may detect force and / or load acting between the inserted robotic member(s), and particularly dynamically rigidizing apparatuses, and the patient’s body to prevent harm and discomfort. In particular, these methods and apparatuses may determine the force(s) and / or load(s) between the inserted robotic member(s) from the proximal end of the inserted members (e.g., the drive sub-assembly) and may provide output including, but not limited to, one or more alerts to the user, and / or may alter the operation of the apparatus base on the determined force(s) and / or load(s). In general, these methods and apparatuses may use sensing inputs from the robot, and in particular, the proximal end of the inserted member(s), such as the driver sub-assembly, and may use those values to determine the force / load on the patient (“patient load”).

[0169] In general, these methods and apparatuses may use a small number of inputs (sensing inputs) to accurately estimate the force / load on the patient. Non-limiting examples of sensing inputs may include: first rigidizing member (e.g., overtube or endoscope assembly) handle insertion axis force measurement, for both insertion and withdrawal directions; first rigidizing member (e.g., overtube or endoscope assembly) handle roll axis torque measurement for both clockwise and counterclockwise directions; position / command data for the insertion axis; position / command data for the roll axis; and the rigidization state for the first rigidizing member. For example, non-limiting sensing inputs for a robot including a nested pair of rigidizing members may include: scope (e g., endoscope or endoscope assembly) handle insertion axis force measurement (both insertion and withdrawal directions), overtube handle insertion axis force measurement (both insertion and withdrawal directions), scope (e g., endoscope) handle roll axis torque measurement (both directions), overtube handle roll axis torque measurement (both directions), position / command data for insertion axes, position / command data for roll axes, rigidization state for both devices.

[0170] As used herein the handle typically refers to the proximal end of the elongate member (e.g., overtube and / or endoscope assembly) that couples to the robot, whether or not manually operated.

[0171] These sensing inputs may be used to track, in real or near-real time, the force(s) or load(s), and these apparatuses may use this sensed input to provide output to alert the user and / or to modify operation of the apparatus to greatly increase safety when operating the apparatus.

[0172] Thus, described herein are apparatuses and methods that include determining (e g., measuring, estimating, approximating, etc.) the force or forces acting on the distal end or distal end region of a rigidizing apparatus inserted into a body. In general, these methods and apparatuses may be part of a rigidizing apparatus. The rigidizing apparatus may be a robotic rigidizing apparatus. For example, the rigidizing apparatus may include at least one elongate rigidizing member that is configured to convert between a flexible configuration and a rigid configuration. Determining the force or forces acting on the distal end or distal region may be referred to as force sensing. In particular, these methods and apparatuses may determine forces on the distal end of a nested inner (and / or in some cases outer) member of rigidizing apparatus (e.g., rigidizing assembly). The force or forces may be sensed at a proximal end of the rigidizing assembly. In general, the forces determined may be load forces acting on the distal end region of the rigidizing member. The force or forces may be determined from one or more proximal force sensors and one or more inputs encoding the rigid state of the rigidizing member(s). The determined forces may be bending forces (e.g., bending moment) or lateral forces, that may act perpendicular to the length of the member, particularly at the distal end region, torsional force (e.g., twisting or torque), axial force (e.g. tension and / or compression) or any combination of these.

[0173] As mentioned, in particular, these forces may be sensed at a proximal end of the rigidizing assembly. For example, the proximal sensors may be one or more strain gauges (e.g., single-axis strain gauge sensing), one or more multi-degree-of-freedom (e.g., a 6 DOF) strain gauge, one or more power (e g., applied current) sensors determining the power driving a proximal movement (e.g., current sensing), one or more elastic sensors (e.g., series elastic sensing). The one or more inputs encoding the rigidity may be pressure sensors (e.g., in variations rigidizing by pressure). The input(s) encoding rigidity may determine the rigidity based on the mechanism causing rigidization of the rigidizing apparatus.

[0174] In any of these methods and apparatuses, the determined force(s) may be used along with the rigidization state of the rigidizing member(s) to provide control feedback for the apparatus, including as part of an algorithm or protocol that may be part of the apparatusand which may enhance safety. For example, the apparatus may continuously determine the force through the rigidizing member(s) representing the load transferred and may respond with one or more outputs based on the type and / or magnitude of the sensed force. In any of these apparatuses, the determined force(s) on the rigidizing members (e.g., the endoscope and / or the overtube in a nested apparatus) may be used to estimate the load applied by the apparatus on the patient based on the determined rigidity of the rigidizing member(s). In some cases the load applied on the patient may generally be determined based on the force (e.g. insertion force) applied to each rigidizing member and based on the rigidization status of each member. The force may be directional (e.g., signed, + / -) and the rigidization status may be Boolean (e.g., true / false) or it may be a scaling factor that is multiplied by the force on the rigidizing member(s). Thus, as mentioned, the patient load may be compared to one or more thresholds to alert the user (e.g., medical professional, such as a doctor, technician, nurse, etc.) of a risk to the patient and / or apparatus, and / or in some cases to control or alter the behavior of the apparatus, including controlling the rigidity of the members, and / or steering, and / or withdrawing / retracting one or both members.

[0175] Thus, described herein are one or more algorithms that may determine the forces acting on patient based on one or more proximally-measured force (e g., insertion force) and the state of rigidization of the one or more members, and may output an alert and / or may control or modify operation of the apparatus. In some cases these methods and apparatuses may provide an output.

[0176] As mentioned above, in general, these methods and apparatuses may include the use of two rigidizing members. In some cases the first rigidizing member may be a rigidizing overtube and the second rigidizing member may be a rigidizing endoscope (or a rigidizing shield covering an endoscope). The first rigidizing member may be nested relative to the second rigidizing member. The methods and apparatuses described herein may also be used with apparatuses including a single rigidizing member and / or methods and apparatuses in which only one of the members (e.g., one of a pair of nested members) is rigidizing, such as a rigidizing overtube with a non-rigidizing endoscope or a non-rigidizing overtube and a rigidizing endoscope (or an endoscope covered in a rigidizing shield).

[0177] Monitoring the forces acting on the robotic apparatuses described herein may be particularly challenging when using apparatuses that can be dynamically rigidized during operation, particularly when inserted into the body, as it may be particularly difficult to predict how the apparatus may interact with the body when operating it from the proximal end region. When using a typical scope, such as a typical endoscope, the user may receive haptic feedback as they operate the device, that may be immediately sensed. Such feedbackmay be difficult or impossible to achieve when using a rigidizing apparatus, and in particular a nested rigidizing apparatus.

[0178] For example, FIGS. 1 A-1D illustrate one example of a robotic scope configured as a nested pair of rigidizing members, which may also be referred to as a nested rigidizing scope. In FIGS. 1A-1D, the nested rigidizing scope 100 includes a rigidizable (e.g., rigidizing) outer member 112 and a rigidizable inner member 110. In FIG. 1A, the steerable inner rigidizing member 110 is positioned within the outer rigidizing member 112 such that the distal end of the inner rigidizing member 110 extends outside of the outer rigidizing member. In some cases the inner rigidizing member 110 may be fully retracted into the outer rigidizing member 112. FIG. IB shows the distal end of the inner rigidizing member 112 is bent slightly in a desired direction / orientation (e.g., via steering cables or other steering mechanism) and then rigidized (e.g., using positive or negative pressure). 112 may also be bent because it was in the flexible state as it followed the curvature of 110, and then was subsequently rigidized. In FIG. 1C, the outer rigidizing member 112 (in the flexible configuration) is advanced over the rigidized inner rigidizing member 110 (including over the bending distal section). Once the distal end of the outer rigidizing member 100 is sufficiently advanced over the distal end of the inner rigidizing member 110, then the outer rigidizing member 112 can be rigidized (e.g., using positive or negative pressure as described herein). In FIG. ID, the inner rigidizing member 110 can then be transitioned to the flexible state (e.g., by removing the positive or negative pressure in some examples, and by allowing the steering cables to go slack such that tip can move easily) and can be advanced and directed / oriented / steered as desired. Alternately, in FIG. ID, the inner rigidizing member 110 can be actively steered (either manually or via computational control) as it emerges such that is minimizes the load on the rigidized outer tube. Minimizing the load on the outer rigidizing member may make it easier for this tube to hold the rigidized shape. Once the inner rigidizing member 110 is rigidized, the outer rigidizing member 112 can be transitioned to the flexible state and advanced thereover. The process can then be repeated to navigate through even more tortious anatomies. However, it may be particularly difficult to coordinate the movement of the inner and outer members, including advancing / retracting and selectively rigidizing either the inner or outer or both, making a robotically controlled system particularly advantageous. The repeated process can result in “shape copying,” whereby the inner and outer rigidizing members, while in a flexible configuration, may continuously conform to (or copy) the shape of whichever member is in the rigid configuration.

[0179] In the examples shown in FIGS. 1 A-1D the apparatus is not shown in the body lumen, however, operation of the apparatus within the body means that there is a risk ofdriving the apparatus against the body lumen, anywhere along the length of the body, which may result in a patient load that may impact both the operation of the apparatus as well as patient comfort. The example robotic apparatus shown in FIGS. 1 A-1D illustrates the operation of just one type of medical instrument that may be used with the methods and apparatuses described herein. Furthermore, these apparatuses may be configured so as to function as endoscopes, including one or more of imaging, irrigation, lighting, steering channels for removing or applying materials, etc. For example, the robotic scope 100 may be a “navigation” device comprising a camera, lighting and a distal steering section. The navigation device (scope or portion of a scope) may be well sealed such that it is easy to clean between procedures. In some examples it does not need to be cleaned because it is fully sheathed, including both on the outside and through the working channels. In some examples a second inner device may then be placed inside the rigidized outer member and advanced past the distal end of the outer member. The second inner member may be a “therapeutic” tube comprising such elements as a camera, lights, water, suction and various tools. The “therapeutic” device may not have a steering section or the ability to rigidize, thereby giving additional room in the body of the therapeutic tube for the inclusion of other features, for example, tools for performing therapies. Once in place, the tools on the “therapeutic” tube may be used to perform a therapy in the body, such as, for example, a mucosal resection or dissection in the human GI tract.

[0180] In some examples, the rigidizing members described herein can transition from a flexible configuration to a rigid configuration and the stiffness may be considered “variable stiffness” as it may be selected by the user or system. For example, each rigidizing member may be rigidized by applying a positive and / or negative pressure to the wall of the rigidizing member or within the wall of the rigidizing member. With the positive or negative pressure removed (or reversed), the layers can easily shear or move relative to each other; the release of the positive or negative pressure may allow the layers to transition to a condition in which they exhibit a substantially enhanced ability to resist shear, movement, bending, torque and buckling, thereby providing system rigidization. Although the examples shown above in the described apparatuses that rigidize by the application of pressure (e.g., positive or negative pressure), the methods and apparatuses described herein may be used with any appropriate rigidizable member(s), not limited to positive or negative pressure rigidizing apparatuses. For example, the rigidizable members described herein may refer to any appropriate rigidizing device, including members that may be rigidized by jamming particles, by phase change and / or shape memory alloys, by interlocking components (e g., cables with discs or cones, etc.), EAP (electro-active polymers) or any other rigidizing mechanism.

[0181] Any of the rigidizable apparatuses described herein may include rigidizing layers or regions that engage with a compression layer (which may be or may include a bladder) that applies force to the rigidizing layer to rigidize the rigidizing layer or in some cases to de- rigidize (e.g., release from rigidization) the rigidizing layer. In some examples, these rigidizable apparatuses may include a rigidizing layer that could include a braid, knit, woven, chopped segments, randomly distributed or randomly oriented filaments or strands, engagers, links, scales, plates, segments, particles, granules, crossing filaments, or other materials forming the rigidizing layer. For example, the rigidizing layer may comprise multiple strand lengths or strand segments that cross over each other (e.g., as part of a braid, knit, woven, etc.); the compression layer may apply force to drive the crossing strand lengths or strand segments against each other. Although many of the examples shown herein are braids, any of these apparatuses may instead or in addition include a general rigidizing layer comprising crossing strand lengths or strand segments. The examples of rigidizing apparatuses described herein may use pressure (positive pressure) and / or negative pressure to selectively and controllable rigidize. In some examples the method described herein may be used with any appropriate rigidizing apparatus.

[0182] In general, the robotic scopes may be actively steered automatically or manually, including by a user operating the apparatus, so that the robotic scope is steered into known, assumed, or measured shapes, when advanced into the anatomy. In some cases the force sensing described herein may be used to assist in manually and / or automatically operating the apparatus. This may be particularly useful and important when navigating a nested rigidizing scope such as (but not limited to) that shown in FIGS. 1 A-1D. For example, a distal end of the inner rigidizing member can be steered (including steering to set or match a shape of the section of the outer rigidizing member). Typically, a region of the inner and / or outer members of the scope may be steered at a region immediately proximal to the distal tip.

[0183] The apparatuses described herein may include effectors for controlling operation of the scope operated by the device, including for steering, rigidizing, navigation, imaging, lighting, etc. For example, the effectors (e g., end effectors) of some variations of the system's robotic arms may include an instrument driver that may incorporate electro-mechanical means for actuating (e.g., steering) the medical instrument and may include a mount assembly for detachably coupling to the scope or portion of the scope (e g., inner member, outer member, etc.). For example, PCT application PCT / US2023 / 064999, filed March 27, 2023, and titled “METHODS AND APPARATUSES FOR NAVIGATING USING A PAIR OF RIGIDIZING DEVICES,” describes examples of apparatuses including nested apparatus that may be used with any of the methods and apparatuses described herein. Other examplesof apparatuses that may be used with the methods and apparatuses described herein may include nested catheters such as those described, for example, in U.S. patent application no. 17 / 902,770, tiled “NESTED RIGIDIZING DEVICES,” filed on September 8, 2022, U.S. patent application no. 18 / 000,062, titled “RIGIDIZING DEVICES,” filed on May 26, 2021, patent application no. PCT / US2022 / 014497, titled, “DEVICES AND METHODS TO PREVENT INADVERTENT MOTION OF DYNAMICALLY RIGIDIZING DEVICES,” filed on January 31, 2022, patent application no. PCT / US2022 / 082300, titled “METHODS AND APPARATUSES FOR REDUCING CURVATURE OF A COLON,” filed on December 22, 2022, patent application no. PCT / US2023 / 062206, titled “DYNAMICALLY RIGIDIZING COMPOSITE MEDICAL STRUCTURES,” filed on February 8, 2023 Each of these applications are herein incorporated by reference in their entirety.

[0184] In some examples, the robotic scope, such as a nested rigidizing scope shown in FIGS. 1A-1D may be robotically controlled. For example, the proximate end(s) of the robotic scope may include connection for connecting the robotic scope to a frame. In the example shown in FIGS. 1A-1D, the outer rigidizing member 112 and the inner rigidizing member 110 may each include controls and / or connections for coupling to steering inputs, air lines (e.g., suction), water lines, video lines (e.g., monitors, et.), and / or one or more tool channels.

[0185] FIGS. 2A and 2B schematically illustrate a first example of a drive sub-system including a plurality of links for deploying and / or controlling a nested rigidizing scope. The apparatus may include the drive sub-system and the nested rigidizing scope (e g., endoscope), and may be configured, as described herein, to sense force acting on the robotic apparatus (and / or the load applied to the patient). In many of the figures described herein, including in FIGS. 2A-2B, the apparatus is shown to be configured for use with a nested endoscope that includes both an outer overtube and an inner endoscope that may be moved proximally / distally relative to each other and may each be rigidized to guide and / or steer the device through the patient’s body (as described above). However, it should be understood that these apparatuses may be used with any flexible tubular member, including those that are not nested and that do not rigidize (e g., single-body endoscopes).

[0186] In any of these examples the robotic driver (e.g., the drive sub-system) may include a plurality of links forming a link assembly. The link assembly may be configured to move the nested rigidizing scope and / or move the inner member relative to the outer member or the outer member relative to the inner member.

[0187] In FIG. 2A, the system 200 (e.g. drive sub-system) shown includes a base 241 that supports the weight of the rest of the apparatus, including any flexible tubular members attached to the drive sub-system. The base 241 may be weighted so as to allow thetelescoping link assembly and any attached flexible tubular member to cantilever distally or proximally away from the base, while remaining stable. The base may house one or more additional components, including power source, power conditioners, motors, pressure source / pressure supplies, controllers, control circuitry, etc. In some cases the base may house the control circuitry configured to receive the force sensor data and to perform any of the operations described herein, including determining patient load and acting on the determined patient load and / or sensed force, such as emitting an alert, and / or modifying the operation of the apparatus. The base 241 may include wheels 251 to allow the apparatus to be moved and positioned relative to a patient’s bed. In some examples the base 241 may include an anchoring region 253 that may be lowered and / or raised to allow or prevent movement. The wheels may be locking or lockable.

[0188] FIG. 2A shows the link assembly 201 configured as a vertically arranged link assembly including three links: a first link 205 (e.g., outer link or base link which may be coupled to the base), a second link 207 (e.g., an intermediate link) and a third link 209 (e.g., inner link). The first link is coupled to the yaw adjust arm 237 that is also configured as (or may be coupled to) a vertical lift arm 235 connecting the link assembly 201 to the base 241. The system 200 shown in FIG. 2A also includes a mount assembly comprising a pair of mount regions 223, 233 that are coupled to the third link. In this example the first mount region 223 is configured as an overtube mount for coupling with an overtube of an endoscope. The overtube mount is located at or near the distal end region of the third link and includes an overtube drive assembly (e.g., driver) 221 that may interface with the overtube of the endoscope. In some examples, the overtube drive assembly may include drive components for controlling roll, for steering (optionally, in examples in which the overtube may be steered at the distal end), and / or pressure inputs / outputs for rigidizing / de-rigidizing. The overtube mount 223 may be configured to secure to the overtube portion separately from the inner endoscope. In some examples the overtube mount 223 may secure by including a securing mechanism such as a clamp, clasp, latch, lock, etc.

[0189] The second mount region 233 is configured as an inner endoscope mount and may also include an inner endoscope drive assembly 231, as shown. The inner endoscope drive assembly (driver) may interface with the inner endoscope member and may include the drive components, including steering components (e g., for steering the distal end / tip region), roll control, pressure input / output (e.g., for rigidizing / de-rigidizing, etc.). The inner endoscope mount 231 may be configured to secure to the inner endoscope separately from the overtube, e g., by including a securing mechanism such as a clamp, clasp, latch, lock, etc.

[0190] FIG. 2C shows another example of a robotic system 200’ including a telescoping link assembly 201 and base 241 similar to that shown in FIGS. 2A-2B. This example also includes a flexible tubular member attached to the system. The flexible tubular member in this example is configured as a nested pair of rigi dizing devices similar to those shown in FIGS. 1A and IB, including an outer overtube 212 and an inner endoscope 210. In this example the base 241 supports the telescoping link assembly 201 and the attached endoscope, so that the link assembly may smoothly move from a relatively low footprint centered neutral configuration to either a partially or fully extended configuration (as shown in FIG. 2B) or a partially or fully retracted configuration, as shown in FIG. 2C. The flexible tubular member may extend distally. In some examples, as shown and described in greater detail below, the apparatus may include one or more supports to prevent buckling or collapse of the flexible tubular member.

[0191] In FIG. 2C and 2D, the link assembly 201 is configured as a vertically arranged link assembly, although any orientation of links may be used (e.g., horizontally-arranged, angled, hybrid horizontal / vertical / angled, etc.). Although three links 205, 207, 209 are shown, any number of links may be included. The flexible tubular member is coupled to the mount assembly coupled to the inner-most (third) link 209. The mount assembly includes a first mount region 223 to which the proximal end region of the overtube 212 is coupled. The first mount region may include a drive assembly 221 including one or more actuators for actuating movement of the elongate flexible member (e.g., overtube). For example, the first mount region 223 may include one or more roll actuators for rolling the overtube relative to the inner endoscope. In some examples the overtube may be steerable, e.g., by including one or more steering members (e.g., pull wires, tendons, etc.). The first mount region may include actuators for actuating the steering of the overtube. The overtube may be connected to a source of pressure (e.g. positive and / or negative pressure) for rigidizing / de-rigidizing the overtube. Thus, the first mount assembly may include a pressure port and may be configured to couple the overtube to the source of pressure. In some examples the source of pressure may be included with the system, or the system may be configured to couple to the source of positive and / or negative pressure.

[0192] The inner endoscope of the flexible tubular member is also connected to the mount assembly, by connection to the second mount region 233. The second mount region may include a second drive assembly 231 including one or more actuators for actuating the flexible tubular member (e.g., inner endoscope). For example, the second mount region 233 may include one or more roll actuators for rolling the inner endoscope relative to the overtube. The inner endoscope may be steerable, e.g., by including one or more steeringmembers (e.g., pull wires, tendons, etc.). The second mount region may include actuators for actuating the steering of the inner endoscope. The inner endoscope may also be connected to a source of pressure (e g. positive and / or negative pressure) for rigidizing / de-rigidizing the inner endoscope. Thus, the second mount assembly may include a pressure port and may be configured to couple the inner endoscope to the source of pressure.

[0193] The mount assembly may generally be configured to move the first mount region and the second mount region relative to each other and therefore move the overtube and the inner endoscope relative to each other. Thus, the inner endoscope may be withdrawn partially or fully into the overtube may extend some distance out of the overtube (as shown in FIGS. 2C and 2D). FIG. 2D shows a top view of the system 200’ of FIG. 2C.

[0194] As mentioned, the mount assembly (e.g., in some examples a first mount region and a second mount region) may be configured to secure to the flexible tubular member generally. The mount assembly may be configured to releasably couple to the flexible tubular member by one or more securing mechanisms such as clamps, clasps, latches, locks, etc. In the example shown in FIGS. 2C-2D, the mount assembly may be configured to separately couple the first mount region of the mount assembly to the overtube, and the second mount region may be configured to separately couple to the inner endoscope.

[0195] As mentioned, these apparatuses may be used with a variety of procedures. For example, these systems 300 may be used as part of a lower GI procedure, as shown in FIG. 3, such as an endoscopy. In these examples, the system 300 including a vertically arranged linear link assembly 301 may be used with a patient 381 virtually any orientation on the bed / cart 382. The system may be positioned on the foot of the patient’s bed. FIG. 3 shows the patient in a side-facing position. FIG. 3 shows a top view of a colonoscopy procedure as described above. The flexible tubular member is part of a system 300 and is inserted and manipulated using a vertically arranged linear link assembly 301. In FIG. 3 the patent 381 remains approximately the same, and the angle of approach may be adjusted, as shown. The system may also be adapted to layout of circular geometry, including a linear exit of the scope. See, e g., PCT application WO2023205655A2, titled “Managing and manipulating a long length robotic endoscope,” and herein incorporated by reference in its entirety.

[0196] A nested rigidizing scope may attach to the link assembly of the drive sub-system. FIG. 4A a link assembly 401 in a fully proximal, retracted configuration. FIG. 4B shows the link assembly of FIG. 4Ain a fully distal, extended configuration. As the link assembly is moved proximally and distally (e.g., sides to extend and retract), the overtube mount 423 moves with the outermost link (e g., the third link 409), telescoping in and out. The inner, endoscope mount 433 may be configured to move distally or proximally relative to theovertube mount (and the link assembly) 433. The inner scope mount 433 may move relative to the outer overtube mount 423, as shown in FIG. 4B, thus extending or retracting (or rolling, in some examples) the inner scope relative to the outer overtube. The link assembly in FIGS. 4A-4B may be mounted to a base at the inner link 405, as shown in FIGS. 2A-2D and 3.Force sensing

[0197] The methods and apparatuses described herein may account for most, if not all, of the types of motion that the robot described above may be in, as well as the kind of loading the patient could see in those scenarios for representative procedures. For a nested pair of rigidizing member as shown in FIGS. 1A-1B using a robotic apparatus illustrated above in FIGS. 2A-2D and 3, this may result in 108 unique motion situations. For each motion situation, either a mathematical analysis or extensive testing was performed to determine how the loads are transmitted to the robot sensing architecture, or both, for a given scenario. For each motion situation a mitigation may be included to detect the full load on the patient that the user can then use to prevent excessive force. In some situations, such as lateral loads due to the bending stiffness of the rigidizing devices, the apparatus may be configured to avoid harm from these loads in the normal use of the device. Any of the methods and apparatuses described herein may be configured to ensure that each of these methods always remains valid.

[0198] In general, the methods and apparatuses described herein may prevent or limit loads (e.g., loads above a threshold) to the patient in both normal and faulted conditions by continuous force monitoring and by the mechanical design of the apparatus. For example, continuous force monitoring may be performed by continuously monitoring insertion forces with force sensors, as described in greater detail below. As forces increase to potentially less safe levels, the user may be notified so that they can take appropriate action. These apparatuses may also include mechanical design that limit or prevent loads on the patient in situations where the loads may not be detectable by the system (such as lateral loads due to the bending stiffness of the rigidizing devices, or if the system is in a faulted condition and cannot detect loads). Thus, these system may be mechanically designed and tested such that these loads will not exert too high of a load on the patient in normal use.

[0199] The analysis and resulting apparatuses and methods described herein considered all of the different motion scenarios the robot might be in during normal use and / or during faults, and the loads that could potentially be exerted on the body in all these situations. In situations where the load that is exerted on the body can be detected, the system can limit that load. If the load cannot be detected, another mitigation may be included. All mitigations maybe either a way to detect the loads fully and continuously in a given situation, and / or to establish a design requirement to prevent excessive load from occurring or from being too large and causing harm to the patient. In the less common event that the loads cannot be sensed or configured to be maintained at a low level, the risk of potential harm can be mitigated by trained users. Thus, the methods and apparatuses described herein may provide at least one enforcement or a clinical assessment that will keep the robot from applying excessive force for all or most of the unique motions of a robot including a nested pair of rigidizing members. This may keep the patient from exposure to excessive forces and torques applied by the robot when using the system. The robotic systems described herein are configured to detect the same insertion forces that an endoscopist would feel with their hands while navigating through the colon. If the robotic system detects the same forces as would be detected manually, then the force limits can be the same as the force limits that an endoscopist would impose on themselves. The system may have multiple force detecting sensors, which combined can detect all of the loads transmitted back through the handles of both the endoscope and the overtube in the same way that an endoscopist feels loads with their hands at the shaft of the endoscope. The highest intubation force or torque an endoscopist may apply to a patient is not the same at all times, and is generally dependent on the situation they are in. Due to this, the methods and apparatuses described herein may not impose a limit on the user but may instead give the user the same information that they would have with a manual scope and lets the user make a decision about how to proceed. The robotic system may, in some cases, enforce a temporary stop at the highest limit (e.g., above a threshold) but may otherwise allow the use to continue navigation based on their judgment.

[0200] These apparatuses may include hardware, software and / or firmware as part of the robotic structure to ensure that lateral and other loads that may be difficult to detect by the robotic system will not cause excessive force on the patient. Redundancy in the sensing architecture and internal checks may be included to ensure that a failure of the sensing subsystem will not go undetected and allow high loads to be unknowingly exerted on the patient. For example, the apparatus may be configured to prevent insertion loads over a first threshold of about 15N (e.g., over 18N, over 20N, over 22N, over 25N, etc.) from being exerted by the robot without warning the physician, e.g., by emitting an alert. The apparatus may be configured to emit an alert when roll torques over about 400 Nmm (e.g., about 450 Nmm, 500Nmm, 525 Nmm, 550 Nmm, 600 Nmm, etc.) applied to the patient. The apparatus may be configured so that loads from the robotic nested system that are unable to be sensed by the robot may be mechanically safe by design.

[0201] The methods and apparatuses described herein may be configured to include different methods by which loads (and / or rotational forces) below a threshold may be maintained during the procedure with regard to force and torque, either manually, semi- automatically or automatically. For example, there may be different methods for different specific sections of each motion situation, which are not mutually exclusive. The majority of methods are safe by design. In general, these methods and apparatuses may be configured to monitor and limit both endoscope and overtube insertion forces individually and / or simultaneously, and may alert the user, as mentioned above. In some cases, these methods and apparatuses may monitor and limit a signed sum of the insertion force and may alter the user and / or may output, e.g., may present the signed sum to the user for assessment. These methods and apparatuses may monitor and limit the endoscope and / or overtube roll torques individually and / or simultaneously, and may output the result, e.g., present the output to user for assessment. In some cases, these methods and apparatuses may monitor and limit the net roll torque, and may output the results, e.g., present to user for assessment.

[0202] The apparatuses described herein may include on or more forces sensors to detect the force acting on the elongate member(s). In variations including a nested set of rigidizing members, e.g., an endoscope and an overtube, the apparatuses described herein may include one or more force sensors sensing the force and / or torque acting on the first member (e g., overtube), and one or more force sensors sensing the force and / or torque acting on the second member (e.g., endoscope). Any of these apparatuses may also include one or more sensors configured to sense the net force acting on both the first and second members.

[0203] In general, the force sensors may be positioned at the proximal end regions of the first and / or second member, such as the ‘handle’ region of the first and / or second members or on the link assembly (including but not limited to the mounts for the first and second member). Thus, in some cases it may be particularly advantageous to include the force sensors within the link assembly. Any of these apparatuses may be configured to return a measure and direction of force on the first member (e.g., the first rigidizing member, such as an overtube). This may be referred to as the overtube force or the force on the first member. Any of these apparatuses may also separately report torque (magnitude and direction) on the first member, e.g., overtube torque. Any of these apparatuses may also be configured to return a measure and direction of force on the second member (e g., the second rigidizing member, such as an endoscope). This may be referred to as the endoscope force or the force on the second member. Any of these apparatuses may also separately report torque (magnitude and direction) on the second member, e.g., endoscope torque. The force on the first member, torque on the first member, force on the second member and / or torque on the second member,as well as the rigidizing status of each of the first and / or second members may be monitored in real- or near-real time and may be output to a controller including on or more processors that is configured to determine and / or analyze the force sensor data to determine the load on the patient. The controller, either remotely or local to the apparatus may then determine a response, such as emitting or presenting an alert, and / or modifying the behavior of the apparatus in response to the force sensor data.

[0204] As mentioned, in general, the methods and apparatuses described herein may estimate forces acting on each of the elongate member (e.g., endoscope, overtube, etc.) separately and / or individually, including determining separate first member and second member force sensor output as well as, in some cases, determining one or more net force sensors, which may measure the net (e.g., total) force applied to both the first member and the second member. In some cases the use of a net force may operate as a semi-redundant input that may be derived from, and thus compared with, the one or more of the individual force sensors.

[0205] FIG. 5 schematically illustrate one example of a first and second mount that may be coupled to a link of a link assembly of an apparatus as described herein; the first and second mount may include force sensors. In FIG. 5, the sensors are arranged to provide accurate and redundant readings to allow detection of failure or a problem with one or more of the sensors. For example, In FIG. 5 the apparatus include a first (e.g., overtube) mount 523 and a second (e g., endoscope) mount 533 that are each coupled to the distal most (e.g., outer) link 509. In This example, the first mount 523 is configured as a driver, driving movement (including in some cases, rotation) of the overtube, and the second mount 533 is configured as a driver, driving movement (including in some cases rotation) of the endoscope. The fist elongate device, e.g., the overtube, may couple at the proximal endo of the device to this first mount. In FIG. 5 the first mount (“OT driver”) is rigidly coupled to the first sensor, configured as the overtube sensor, for sensing force between the overtube and the patient. The overtube driver is coupled to the distal link 509 by a set of linear bearings 550. The second mount (“endo driver”) 533 is also coupled to the distal link 509 by one or more sets of linear bearings 550’, 550”. In this example the second sensor, the endoscope sensor, is configured for sensing force between the endotube and the patient. FIG. 5 also illustrates an example of a force second configure to determine the local net force by sensing between the first mount 523 (e.g., the OT driver) and the distal link 509. This first net sensor may be configured so that it is connected on a first side to both the first mount (e.g., the OT driver) and to the second mount 507 (e.g., the endo driver) and on the opposite side to the distal link. The second mount (endo driver) is coupled to the first side of the local net sensor via a rack gearand one or more sets of linear bearings, and also by a bridge structure 545. The schematic shown in FIG. 5 also includes a second net sensor 546 that is within the distal link (e.g., between a net plate coupled to the distal link by one or more linear bearings and the distal link) and is configured to sense the net force applied against the nested apparatus (both the first and second members). In practice these sensors may be configured to provide good force measurements and may be isolated from many disturbances. The local NET sensor may be particularly useful for sum checking the first (e.g., overtube) and second (e.g., endoscope) force sensors, as it may see the same forces as these sensors. In some cases the net sensor may be located between the distal link and the net plate with its own set of linear rails. In this configuration, because the net sensor is entirely separate from the endoscope and overtube sensors, it should be subject to very few common mode failures that would affect multiple sensors similarly and simultaneously. For example, if the linear bearings around the overtube sensor seize up, the net sensor would still correctly measure the net force and the failure of the overtube sensor would be observable. This may provide a robust redundancy. However, in this configuration the disturbance forces may not cancel, where disturbance forces may be those forces that do not reflect the force between the first and / or second members and the body, but are still registered by the force sensors. This may result in a somewhat higher failure detection threshold.

[0206] The example shown in FIG. 5 also includes a local net force sensor, as described above. In this example the local net sensor may be collocated with and receive input from both of the first (OT sensor) and second (Endoscope sensor) sensors. This configuration has the advantage of relatively mechanical compactness and, if used without the other net sensor, may eliminate the net plate. It may also have other advantages, including not using additional linear bearings, and therefore it does not introduce any distinct disturbance forces, but reflects the same disturbance forces as the endoscope sensor and overtube sensor. Thus, this design may have good sensitivity to detecting subtle failures in any of the three loadcell. Although the local net sensor is subject to the same disturbance forces as the endoscope and overtube sensors, it may not provide additional redundancy to detect a failure or change in those disturbance forces. Note that although FIG. 5 illustrates an example with both a Net sensor and a local net sensor, it should be understood that in some cases, only one net sensor, either the net sensor between the distal link and the net plate, or the local net sensor, may be used

[0207] For example, FIG. 6A schematically illustrates a first mount and a second mount that may be connected to a robot (e.g., a link of a link assembly) including the force sensors integrated therein including a single net sensor 646. In this case the net sensor may be redundant and is positioned between the outer link 609 and a plate (net plate) 615 on the linkassembly. A first (e.g., overtube) sensor 641 that is configured to output the force acting on the first elongate rigidizing member (e.g., overtube) is coupled between the first (e.g., overtube) mount 623 and the outer (distal) link 609. The apparatus also includes a second (e.g., endoscope) sensor 643. In this case the endoscope sensor 643 is coupled between the second (e.g., endoscope) mount 633 and the outer link 609. The net force should be the sum of the force acting on the first sensor and the second sensor.

[0208] FIG. 6B shows another example of a first mount 623’ and second mount 633’ that may be with any of the apparatuses described herein. This example apparatus includes redundant force / load sensors for both the first force / load sensor(s) 641, 641’, e.g., for sensing force / load on the first elongate rigidizing member (e.g., overtube 691) and redundant second force / load sensors(s) 643, 643’ for sensing force / load on the second elongate rigidizing member (e.g., endoscope assembly 690). The apparatus may compare the redundant force sensors to detect an error in the system and may trigger a warning or alert if they do not match. In this example the force sensors are between the first 623’ and second 633’ mounts and the link 609’. The link is part of the telescoping robot. This example does not include a dedicated net sensor but may derived net force / load based on the first sensor(s) and second sensor(s).

[0209] Also described herein are systems that include one or more torque sensor(s) for determining torque acting on the apparatus. For example, FIG. 6C shows a schematic illustration of an apparatus including a torque sensor that may be used to determine torque acting on the body as described herein. In FIG. 6C the coupling of the linkage 609” to the mount 623” creates an off-axis virtual pivot that may be used to detect a ta foil moment when rolling the first elongate rigidizing member 691 that can be detected by the sensor(s) 670, 670’ between the link and the mount (in this example, a vertical mount). A force / load sensor (load cell) is positioned between the link and the mount. Thus, any of these apparatuses may be configured to sense roll torque.

[0210] In general, the force sensed by each of these sensors (first, second, net, etc.) is signed, meaning that the direction of force (proximal / distal) is reflected in the sign of the sensed force. Force acting in the distal direction may be positive and force acting in the proximal direction may be negative, depending on convention (or vice versa). Since force is acting in a line for the linear force sensors, the sign may accurately convey the direction of force. The same sign convention (e.g., positive for distal / insertion force, negative for proximal / withdrawal force) may be used for both nested members. Torque may be sensed similarly, with the direction of rotation being reflected by the sign of the sensed torque.

[0211] In practice, any appropriate force sensor may be used for the first, second and / or net force sensor. For example, the force sensors described herein may be strain gauge sensors (e.g., Futek LSB210 - FSH03943, lOOlbs load rating, 200% RO). Any appropriate force sensors may be used, including but not limited to capacitive sensors, inductive sensors, piezoelectric sensors, piezoresistive sensors, load cells, force sensitive resistors, etc.).

[0212] FIG. 7A illustrates an example of a force sensor 741 comprising a strain gauge in this example, configured as a first (e.g., overtube) sensor measuring forces acting the first member, e.g., overtube, mounted between the first driver 723 and the outer link 709. FIG. 7B shows the first driver with the link removed, showing the linear bearings 850 between the first driver 723 and the outer link. The strain gauge 741. The strain gauge may be connected to a power and / or data line that may be part of a plurality of cable 855 (shown here as part of a cable harness or loop of cables) the cables may be retained with one or more strain-relief members 852, 853 that may prevent the cables from interfering with the operation of the apparatus. The strain gauge (force sensor 741) is mounted to the link on one side and to the driver on the opposite side; in FIG. 7B this mount is shown as pin and slot interface 855.

[0213] Any of the apparatuses described herein may use a flexure as a force sensor, as mentioned above. For example, FIGS. 8A and 8B illustrate an example of a portion of a link assembly 800 including a flexure 855 as one of the force sensors. In this example, the flexure may be configured to detect force acting on first link between the inner member is driven (e.g., on the rack 858 by a gear 856) proximally and distally relative to the link. Any appropriate flexure may be used, including a region having a neck or narrowing that may deflect slightly depending on the forces applied on either sides of the flexure. FIG. 8B shows an example of an encoder 853 and encoder circuitry 854 that may be used to readout the position from the flexure. In some cases a flexure may be used in combination with one or more other flexures, and / or one or more strain gauges (e g., as shown in FIGS. 7A-7B). For example, either a flexure or a strain gauge may be used as a first (e.g., overtube) sensor measuring forces acting the first member, e g., overtube, mounted between the first driver 723 and the outer link 709.

[0214] Another example of a second mount 933 assembly, configured as the endoscope driver mount assembly, including a force sensor is shown in FIGS. 9A-9B. in this example the endoscope mount 933 is attached via one or more gears, e g., shown as a rack gear 961 and linear bearings 963, to the link, so that the second mount may move axially (proximal / distal) relative to the first driver and relative to the more distal first mount for the overtube. A set of linear bearings 950’ is positioned between the second mount and the outer link. The force sensor 943 in this example is a strain gauge that is coupled (via a pin and slotinterface 948) between the second mount 933 and the outer link (not shown in FIG. 9A and shown as transparent in FIG. 9B) 907. The force sensor, e.g., strain gauge, in this example may thus identify the force between the endoscope and the body once the endoscope is coupled to the mount. The mount 933 also includes a plurality of drivers 966 for actuating tendons, such as steering tendons, on the endoscope when the endoscope is coupled to the mount. The second mount assembly also includes an idler gear 971.

[0215] In FIG. 9A-9B the portion of the link assembly shown including the endoscope mount also includes a tool driver 977 that may be attached to the second mount. The tool driver may engage over a tool inserted with and / or through the endoscope and may drive insertion / withdrawal of the tool and / or rotation (e.g., torquing) of the tool. Either or both the overtube and endoscope mounts may also include one or more sensors 973 for sensing when the overtube and / or endoscope is coupled to the respective mounts.

[0216] Any of these method and apparatuses may include one or more pressure lines supplying positive and / or negative pressure to the first member (e.g., overtube) and / or the second member (e.g., endoscope). The pressure may be used to control rigi dizing of the apparatus. In any of these apparatuses one or more sensors may be used to determine the pressure applied to the first and / or second member. The one or more pressure sensors may be an independent sensor that may be in-line with the one or more pressure line. Alternatively or additionally, one or more pressure sensors may be configured to detect pressure applied to the one or more pressure lines, e.g., from a separate or included source of pressure. As will be described in greater detail herein, the pressure applied to the first and / or second members or the pressure within the one or more pressure lines may be used to determine the rigidity of the first and / or second members. In examples in which each of the first and second members are rigidizing, a first pressure may be sensed either from the pressure source and / or the pressure line(s) and / or the first member and this first pressure may be converted to an indicator of the rigidizing state of the first member (e g., overtube). Similarly a second pressure may be sensed either from the pressure source and / or the pressure line(s) and / or the second member and this second pressure may be converted to an indicator of the rigidized state of the second member (e.g., endoscope). The indicator(s) may be left as a pressure value and / or the indicator may be converted from a pressure value to a rigidity and / or flexibility value.

[0217] FIGS. 10A-10B also illustrate one example of a net forces sensor that is configured to measure the net force on both the inner and outer members, e.g., both the overtube and the nested endoscope in some examples. In FIG. 10A a net force sensor 1046, configured as a strain gauge, may measure the net force applied on the nested overtube andendoscope assembly, as described above. In FIG. lOAthe strain gauge 1045 is mounted via a pin and slot interface 1054 to the distal link 1009 on one side, and to a net plate mount 1015. In FIG. 10B the net plate has been made partially transparent. A pair of net plate rails 1039 are shown on the outer link. In FIG.10B an attachment 1067, e.g., post, coupling etc., for one or more fluid lines is shown coupled to the net plate 1015. Attaching the fluidic lines may reduce disturbances from the fluidic lines when sensing.

[0218] In variations including a local net sensor, such as that system shown in FIG. 5, the local net sensor 1042, e.g., strain gauge, may be positioned between the first and second sensors coupled to the outer link 1009, shown in FIG. 11 A. FIG. 11B shows an alternative example without the net force sensor; in this example the apparatus includes the first and second sensors 1077 (e.g., endoscope strain gauge and overtube strain gauge), but the optional local net sensor is not included.

[0219] FIG. 12 schematically illustrates an example of the local net force sensor configured so that the local net force sensor is mounted between the overtube sensor and the endoscope sensor and parallel to the endoscope sensor. In this example, the first sensor, e.g., overtube strain gauge 1241 is coupled in communication with the first end of the local net force sensor 1242, and the second sensor, e.g., endoscope strain gauge 1243 is also coupled in communication with the first end of the local net force sensor. The second end of the local net force sensor is coupled to the distal link via a mount 1249. The local net sensor itself may be mounted via the local net sensor frame 1256. This arrangement is shown schematically in FIG. 13, which is similar to that shown in FIG. 5. In this example, the force sensors are arranged in-line to eliminate moment loads / additional hardware, as shown in FIG. 14. In FIG. 14 the arrangement of the three force sensors are shown in-line coupled to the first link.Determining Patient Load

[0220] The methods and apparatuses described herein may determine the load on the patient using a robotically controlled rigidizing apparatus, as mentioned above, in particular, these apparatuses may be configured to determine the load on the patient when using a nested rigidizing robotic apparatus. FIG. 15 illustrates an example of a patient load estimator (also referred to herein as a patient load monitor) configured to estimate the patient. The same estimator or a separate estimator may be configured to monitor torque, by sensing torque acting on the endoscope, overtube or both and using the signed sum of the two to estimate the torque acting on the patient. In some cases only the inner and / or only the outer member may be configured to be rotated (e.g., torqued).

[0221] In FIG. 15, the patient load estimator 1510 is configured to receive input or otherwise access insertion force from the first member (e.g., overtube insertion force 1505),the insertion force from the second member (e.g., endoscope insertion force 1503) and optionally the net insertion force 1507 (e.g., the signed sum of the first and second insertion forces). In addition, the patient load estimator 1510 is configured to receive input or otherwise access the rigidization status 1501 of the first and / or second members, e.g., indicating if the first and / or second members are in a more rigid or more flexible configuration; in some cases the rigidization status may be a Boolean (e.g., “true” or “false”) input, while in some cases the rigidization status may be a matter of degree (e.g., the degree of rigidity and / or flexibility) and / or an indicator of the magnitude of the rigidity / flexibility of the first and / or second members. The rigidization status maybe inferred by determining a pressure (e.g., fluid pressure) within the first and / or second members that are pressure- rigidizing.

[0222] The apparatus may include software, hardware and / or firmware (including one or more processors and a memory storing instructions configured to perform the method described herein) to determine the rigidization state 1509, e.g., by confirming the pressure within the first and / or second rigidizing members. Based on the result, if the first (e.g., outer or overtube) member is rigid, the patient load estimator 1510 may set as an output for the patient load output 1517 whichever is greater, the insertion load of the first (overtube) or the second (endoscope). If the overtube is instead in the flexible state (e.g., if the pressure within the rigidizing bladder of the overtube is less than a threshold, or is approximately equal to air pressure / ambient pressure), the patient load estimator 1510 may check the rigidization status of the second member (e.g., the inner member, e.g., endoscope) 1511. If the second member is rigid, then the patient load estimator may compare the insertion forces of the first and second members (e.g., may compare the signs of the insertion loads for the first and second members) and, if the signs are the same, which may occur when force is being applied in the same direction, then the patient load output may be set to whichever insertion force is greater 1517. Alternatively, if the insertion forces have different signs, then the output may be the net value of the first and second loads (e.g., the signed sum of the first insertion force and the signed sum of the second insertion force) 1515. Similarly, if the first (e g., overtube) is flexible and the second (e.g., endoscope) member is flexible, the output may again be the signed sum of these insertion forces.ANALYSIS

[0223] The force sensing and thresholds were investigated for one example of a robotic system including a nested pair of rigidizing apparatuses. The results of this investigation are described in detail below and may be used to generalize to similar rigidizing system, including single rigidizing apparatuses, or other configurations of dual rigidizing systems.

[0224] Different modes of operation were examined. For example, a nested rigidizing apparatus was examined during withdrawal (e.g., “withdrawing mode”), in which both endoscope and overtube are flexible, and steering is enabled. Both units can roll simultaneously or independently. The kinds of loads that could be applied to the nested set while driving in this mode were examined to see how these loads affect the patient's colon. A free body diagram (FBD) of the nested set in this mode, may be used to look at several situations where the overtube might be flush or not to the endoscope tip, or the bending section may be bent. By examining each of these loads in every direction they may be pointing, based on the motion situation that the system is in, it can be ensured that all of the blocks in the motion situation matrix for this mode are covered. In this analysis, it was desired to determine whether the robot can detect the magnitudes of each load, which would allow them to be limited if they become too high to prevent harm. If the loads cannot be detected, a way to ensure they are maintained at a low level by design may be used (so that the patient cannot be harmed when the device is used correctly) and / or that they are safe when the user is properly trained to use them. These loads were broken down into a few groups with the same mitigation and explanation, each of which will be covered below. The loading groups may be each be described to determine which situation applies.

[0225] FIG. 16 shows an example of free body diagrams schematically illustrating different operational conditions for the apparatus.

[0226] For example, the load on the body may be determined in each situation, including when the flexible scope is being steered (e.g., by driving one or more cables / tendons to steer the distal end), or is not being steered. Table 1 illustrates example of these states, and each of the resulting groups (la- Id, 2a-2g) are described below.Table 1: conditions of states for withdrawal la Not steering: Fbody2, Fbody5, and Fbody6

[0227] In order to understand how the robot might detect these loads, it must be first looked at how endoscopists would detect similar loads with a manual colonoscope. The loading scenario with a normal colonoscope can be classified as either sliding or stretching. In sliding, the colonoscope is progressing along the tissue lumen, and the loads that it experiences are the sliding friction and the load at the tip. In stretching, the colonoscope is not sliding along the tissue, is experiencing static frictional loads keeping it from progressing, and is now stretching the tissue like a spring. A typical colonoscope allows the user to only detect loads at the handle in either of these situations. The endoscopist will limit the handle loads to the same threshold regardless of if the system is in the sliding or stretching condition. This is illustrated in FIG. 17, showing the forces when the scope is sliding along tissue walls.

[0228] In these diagrams, the value C (capstan equation) is the only load that the endoscopist has access to. In neither the sliding nor the stretching situation can they detect each of the loads exerted at different points on the colon separately and individually, they can only limit what load they push on the colonoscope with based on the value of C. Because the system in this Withdrawing Mode is completely flexible and both units are moving in the same direction simultaneously, how the robot detects loads can be modelled in the same way, drawing the same free body diagram. The robotic system can detect loads at the handles of each device, so with both of those loads together, it is essentially detecting loads in the same loads in the system the same way an endoscopist would.

[0229] FIG. 18 illustrates the stretching forces when the colonoscope is stuck on the tissue walls. In FIG. 18, looking at Fbody2, Fbody5, and Fbody6 when the robot is not steering, the figure shows the scenario in which the device might experience these loads is when there is a shear force on colon walls when withdrawing, or when pulling back on a loop with too much force, as shown below. These loads would be the most common during reductions.

[0230] For these loads, they cannot be exerted onto the tip in the -z direction because in this withdrawing mode the software may be configured to disallow the user to move the devices in the +z direction. As for loads that are acting in the +z direction when the devices are moving in the -z direction, these loads the robot will be able to detect at the handles by the same method with which physicians detect loads at the handle of a manual colonoscopebecause they are transmitted down the length in the same way that loads are transmitted with a manual colonoscope since both devices are flexible during withdrawal.

[0231] The loads may be applied to two different devices, the inner and the outer members. The robot may be configured to receive the measurement of the loads on each the endoscope and the overtube separately, so it should be able to see the magnitude of each of the loads Fbody2, Fbody5, and Fbody6. For this particular type of load, the majority of the load on the colon is from the overtube because this is a fundamentally frictional load from sliding on the walls, and the overtube has much more surface area contacting the walls. However, the overtube is not taking on the entirety of the load every time, there are still relevant loads on the endoscope. Because the two elongated members are moving in the same direction at the same time, the robot should not look at the loads on each of them separately because it would end up with two loads that are lower than the complete load that the colon is seeing. It is shown in the graphs in FIG. 19 that in some situations the overtube takes on the entire load, and in others it only takes on some of the load. Only by looking at the combination of their two values can it get the complete picture. The graph in FIG. 19 is from a navigation run through a realistic tissue model (RTM), with the model in a tortuous configuration. The first line 801 indicates the absolute value of the measured load at the overtube handle, and the second line 805 indicates the measured load on the endoscope handle. The third line 807 indicates the measured net load on the model as measured by the real-time acquisition of force and torque.

[0232] During this reduction, both the endoscope and the overtube experienced separate loads. Because they were measured through two different locations, neither the endoscope measurement nor the overtube measurement matches the third line, and therefore the robot can’t get the whole story by looking at them separately. But since they are moving the same direction, it can treat them as one entity and combine their measurements to get what the total load of this fused nested set is. This is done to this set of data in the graph in FIG. 20.

[0233] It can be seen in FIG. 20 that the first line 901 matches the second line 903 much closer and is even reading a higher load. It may be assumed that the two devices are moving perfectly in sync, which at the handles this is true, but if the endoscope and overtube are not perfectly axially stiff, they will stretch somewhat and move a small amount relative to each other. This frictional load may be measured by each of the handle force gauges and may add to the combined load, giving the robot a higher measurement than what the colon is actually seeing (the second line 903 line as measured by the real time acquisition of force and torque). But since the robot is not concerned that it over measures a load, only that it might undermeasure a load, this additional buffer in measurement is not a concern. This is applicable to all tortuosity. lb) No steering: Fti l and Ftip2

[0234] Looking at Ftipl and Ftip2 when the robot is not steering the scenario in which the device might experience these loads is if the tip of the endoscope gets wedged around a comer or flexure, as shown in FIG. 21. For these loads, the robot can detect the entirety of the load in the same way as described above in situation la. The load exerted at the tip of the endoscope will be transmitted down the length in the same way that loads long the body are transmitted. lc) No steering: Fbodyl and Fbody4

[0235] Looking at Fbodyl and Fbody4 when the robot is not steering, the scenario in which the device might experience these loads is when the flexible proximal body of the nested pair is pushed around a bend in the colon, and the colon experiences the normal load from the restorative bending stiffness of the nested pair as it tries to push back into a straight pose. This is illustrated in FIG. 22. To test what kinds of loads the system exerts on the colon in this manner, the force that manual colonoscopes exert when in this pose and compared these values to a typical nested robotic endoscope and overtube pair was looked at. The following procedure was followed: (1) rigidly mount handheld force gauges with flat measurement surfaces 4” apart on the surface; (2) place the device to be measured in a curve between the two handheld force gauges at the desired position along the length; (3) place the excess length of the device roughly tangent to the curve so that the device is only seeing 180 degrees of tortuosity; and (4) record the values on each handheld force gauge. The nested pair in this analysis was hooked up to a robot at the time but not actively steering. For the manual device, because they are often variable stiffness along the length of the device, it was measured in 3 separate locations. The robotic nested pair were both flexible devices.

[0236] The results showed that if the device exerts a lower load on the colon walls from the bending stiffness than a manual colonoscope, then the devices are safe by design with regard to loads Fbodyl and Fbody4. ld) No steering: Fbody3

[0237] Looking at Fbody3 when the robot is not steering, the scenario in which the device might experience these loads is if the tip of the endoscope gets wedged around a comer or flexure, the same scenario as for Ftipl and Ftip2, except now looking at the lateral load. This is illustrated in FIG. 23. In this example, the robot cannot detect the lateral loads like this with the robot but can reduce them by having an atraumatic tip. It also must be configured so that the length of this stiffer bending section is not so long that it will forceopen tortuous paths that are much more proximal to where the user can see, thus making the method of watching the lumen while navigating this direction less effective at preventing wedging.2a) While steering: Ftipl and Ftip2

[0238] Looking at Fbody2, Fbody5, and Fbody6 when the robot is steering, the scenario in which the device might experience these loads is if the user is steering into walls as shown in FIG. 24. This situation is similar to withdrawing mode la and lb, where the robot can detect these types of loads on the endoscope.2b) While steering: Fbodyl and Fbody3

[0239] Looking at Fbodyl and Fbody3 when the robot is steering, the scenario in which the device might experience these loads is if it pushes around the colon walls while steering around bends. This is illustrated in FIG. 25. This situation is similar to withdrawing mode Id, where the robot cannot detect these types of loads, so it must implement other mitigations described in withdrawing mode Id. Additionally, another mitigation that must be imposed will be on the user while they are navigating is to train them to maintain a clear view of the lumen as much as possible to minimize the occurrence of this load.While steering: Fbody5, Fbody6, Fbody7

[0240] Looking at Fbody5, Fbody6, and Fbody7 when the robot is steering, the scenario in which the device might experience these loads is when the bending section is not fully exposed from the overtube, and there are loads on that section along the device. This is illustrated in FIG. 26. This situation ends up being similar to withdrawing mode 2b, because while the overtube is now covering the endoscope bending section, the bending section still does not have the same properties as the rest of the proximal length of the nested set, so the robot can’t look at this situation the same way that was done in withdrawing mode 1c. This situation is, however, safer than in withdrawing mode 2c because the apparatus may be configured to limit the bending section to a smaller articulation because when the tips of the devices are flush, the endoscope cannot steer as well. Therefore, the occurrence of lateral loads on the bending section from the colon wall in this situation is even further reduced. 2e) While steering: Fbody2

[0241] Looking at Fbody2, Fbody5, and Fbody6 when the robot is steering, the scenario in which the device might experience these loads is when hooked around a bend and continuing to pull the devices back. The concern in this configuration is around whether a load that is exerted on the bending section is transmitted down the length of the device in the same way a load exerted on the shaft is transmitted.

[0242] This situation is similar to that of la, but the robot may be configured to detect the loads in the same way when they are applied on a hook in the bending section, which is technically a lateral load. This test was performed on the robot and on the test fixture to see if it could detect the loads applied like this on the bending section rather than on the body of the endoscope. The robotic endoscope and overtube were mounted to the robot, and, after navigating to the cecum, the endoscope was deliberately hooked around a flexure and withdrawn until the flexure seemed to be stretched (shown in FIG. 28). The test fixture collected forces and torques felt by the model, and the robot collected data on forces in the insertion axis on both the overtube handle and the endoscope handle. By comparing the data in the second graph, the robot load cells detected the entirety of the load that was exerted on the model in this test. This gives confidence that the robot can detect high loads in this scenario to protect the patient.2f) While steering: Fbody4 and Fbody8

[0243] Looking at Fbody4 and Fbody8 when the robot is are steering, the scenario in which the device might experience these loads is when the flexible proximal body of the nested pair is pushed around a bend in the colon, and the colon experiences the normal load from the restorative bending stiffness of the nested pair as it tries to push back into a straight pose. This is shown in FIG. 29. The only difference between this situation and withdrawing mode 1c is that when the bending section of the endoscope is being steered, the proximal bending stiffness of the nested pair increases, and potentially can increase to a value that is greater than the stiffness of the manual colonoscopes compared against previously. If this is the case, instead it must be looked at what stiffness of this proximal section would actually cause damage to the colon. This value can be based on the maximum conservative force used to push on a colonoscope to intubate. This is possible because in both scenarios the situation the robot is concerned about is the proximal section of the device displacing tissue with great enough force to cause a mesentery tear and / or perforation, so the limit to these loads would be the same.2g) While steering: Fbody9 and FbodylO

[0244] Looking at Fbody9 and FbodylO when the robot is steering, the scenario in which the device might experience these loads is when there is a shear force on colon walls when withdrawing, or when pulling back on a loop with too much force, as shown below. These loads would be the most common during reductions. Because steering in the bending section does not change how the loads transmit down the length of the devices, this situation can be looked at in the same way as withdrawing mode la and withdrawing mode 2e.Torques

[0245] In all the previous analyses, only the forces were looked at. The torques may also be examined. For example, in some cases reduction may be performed while in withdrawal mode, in which both flexible devices rotate in order to undo a loop that has formed in the anatomy. Both units would be exerting a torque on the colon in this situation, as shown in FIG. 31. A test was performed on the robot and on the test fixture (measuring real-time force and torque) to see if it could detect torques applied by the robot on the colon while driving. The robotic endoscope and overtube were mounted to the robot, and, after navigating past the sigmoid colon through an alpha loop, the alpha loop was reduced by rolling both the flexible endoscope and the flexible overtube in unison. The test fixture collected forces and torques felt by the model, and the robot collected data on forces in the torque axis on both the overtube handle and the endoscope handle separately. In the graph of FIG. 32, the first line 3203 is the torques measured by the endoscope handle, and the second line 3201 is the torques measured by the overtube handle. The third line 3205 is the torque in the axis of interest measured by the test fixture (e g., real-time force and torque). In FIG. 32, it can be seen that just like in situation withdrawing mode la above, the torque measured by just the endoscope is not quite enough to cover the entire torque felt by the colon. This is because both units are moving simultaneously in the same direction and therefore are sharing the torque that is exerted on the colon. In order to reflect this, the robot can again combine the torques to be able to look at the total torque exerted on the colon. The graph in FIG. 33 shows this calculation. By comparing the data in the graph of FIG. 33, it can be seen that the robot load cells detected the entirety of the load that was exerted on the model in this test when the measured values were combined in the handles. The robot over-detects this load due to other factors sch as small amounts of friction between the devices, tubing lines adding torque to the measurement, and other external factors, but they add torque in a direction that makes the system more conservatively measure the load of interest. This gives confidence that the robot can detect high loads in this scenario to protect the patient.Methods for Withdrawing

[0246] Putting all of this information together, two tables can be created, and for each load it can be described what scenario may cause that load and what the mitigation is for that scenario, in reference to FIG. 16 (e.g., mitigation to prevent loads and / or rotational forces greater than a threshold)Table 2: When not steeringTable 3: When steering

[0247] This mapping may then allow a corresponding methods for withdrawing for each type of load, generating a motion situations matrix. The matched approach to each load on the device may be enumerated as shown in Table 4, below:Table 4: Motion situation matrixThe Withdrawing Mode Algorithm

[0248] For the unified algorithm when withdrawing, the minimum number of different techniques may be used to keep it as simple as possible. Because some of these external loads are applied to the overtube and some are applied to the endoscope, the loads read by both the endoscope handle and the overtube handle must be looked at. If the robot monitored each of those loads individually, it would also not get the whole story because both of them are moving at the same time and in unison, so the loads they apply to the body are additive. Thus, in order to get the whole picture, the apparatus may monitor the combined load on the overtube and the endoscope together and limit the device motions based on this value. This applies to both the insertion forces and the roll torques. In order to avoid load interference between the devices when rolling, the system may be limited when in withdrawing mode to never roll the devices relative to each other and only roll them in unison. This would conservatively cover all the situations listed above that it is possible to measure the loads in. For the unmeasurable loads listed above, the system may be configured so that it won’t applytoo high of a load or may otherwise limit the system in a way that will prevent or limit the occurrence of these loads.Investigation of Motion Situation: Worst Case Faulted State

[0249] In one particular situation the robot may be in a nonrecoverable fault condition, without the ability to drive axes, and without the ability to measure loads. Both units may be de-rigidized. This scenario may be applicable for any number of degrees of tortuosity or articulation in bending section.

[0250] A workflow associated with this fault event may be as follows: if the robot is in an undetermined pose, an unrecoverable fault occurs, all units de-rigidize, all axes are undriveable, all sensors do not detect loads, the user removes any tools from the working channel, the user manually removes the handles of the endoscope and overtube from the drivers on the robot, and the user removes the endoscope and overtube manually from the patient. First, the kinds of loads that could be applied to the nested set while in this situation are examined to see how these loads affect the patient's colon. By examining each of these loads in every direction they may be pointing, based on the Motion Situation, it can be ensured that all of the blocks in the Motion Situation Matrix for this mode are covered. A Free Body Diagram (FBD) of the nested set in this mode, considering several situations where the overtube might be flush with the endoscope tip, or the bending section may be bent, is similar to that shown in FIG. 16, in which the left two models show examples without steering and the right two examples (showing steering / bending in the two examples on the right side). This situation is very similar to the one above, in that both units are flexible, but dissimilar in that the system no longer has control over the device via the robot or any ability to sense the loads. The robot also could have gotten into this state from any situation, so it is not limited to motions that are done in the withdrawal state. The same loads as in the withdrawing mode were examined, but this time with these key differences in mind. Tabe 5 shows a summary of these conditions:Table 5: summary of conditions (fault modes) la) No steering: Fbody2, Fbody5, and Fbody6

[0251] Looking at Fbody2, Fbody5, and Fbody6 when the robot is not steering, the scenario in which the device might experience these loads is when there is a shear force on colon walls when withdrawing, or when pulling back on a loop with too much force, as shown below. These loads would occur if the user had driven into any kind of tortuosity prior to the fault and must remove the device from the patient manually. It was shown in withdrawing mode la that these loads are fully detected at the handles of the devices. In a fault situation, the user may remove the device manually and may experience these loads as they do so. The loads may travel down the length of the device in exactly the same way described in withdrawing mode la, except this time the user is the one limiting the forces on patient instead of the robot. The user removing the devices must therefore be a trained physician with knowledge of what loads are too high. The devices need not be removed simultaneously. lb) No steering: Fti l and Ftip2

[0252] Looking at Ftipl and Ftip2 when the robot is not steering, the scenario in which the device might experience these loads is if the tip of the endoscope gets wedged around a comer or flexure, as shown in FIG. 21. For these loads, the user removing the units can detect the entirety of the load in the same way as in fault mode la. The load exerted at the tip of the endoscope will be transmitted down the length in the same way that loads long the body are transmitted. lc) No steering: Fbodyl and Fbody4

[0253] Looking at Fbodyl and Fbody4 when the robot is not steering, the scenario in which the device might experience these loads is when the flexible proximal body of the nested pair is pushed around a bend in the colon, and the colon experiences the normal load from the restorative bending stiffness of the nested pair as it tries to push back into a straight pose. This is also illustrated in FIG. 22. This situation is exactly the same as in withdrawing mode 1c and therefore can use the same approach or technique to maintain the patient load within or below a desired range. ld) No steering: Fbody3

[0254] Looking at Fbody3 when the robot is not steering, the scenario in which the device might experience these loads is if the tip of the endoscope gets wedged around acomer or flexure, the same scenario as for fault mode lb, except now it is looking at the lateral load. This is also illustrated in FIG. 23. Just like with the robot, the user cannot detect these lateral loads on the device. These loads would be reduced in this situation the same way as in the withdrawing mode, by giving the endoscope an atraumatic tip and limiting the length of the bending section design. The robot cannot, however, control the steering of the device, so the bending section distal end must be back drivable enough so that when the handle is removed, it can be straightened and bent with little enough force that it won’t cause a too high insertion force when removing the device, or, failing that, that the bending section is steerable by hand with the proximal pulleys by the user to dislodge the bending section to remove the entire unit. With the current design of the device, the bending section of the endoscope is easily back drivable by hand and does not require a high load to straighten.2a) While steering: Ftipl and Ftip2

[0255] Looking at Fbody2, Fbody5, and Fbody6 when the robot is steering, the scenario in which the device might experience these loads is if the user is steering into walls as shown in FIG. 24. This situation is similar to fault mode la and fault mode lb, and the entire load can be detected by the user while removing the endoscope.2b) While steering: Fbodyl and Fbody3

[0256] Looking at Fbodyl and Fbody3 when the robot is steering, the scenario in which the device might experience these loads is if the device pushes around the colon walls while steering around bends. This is illustrated in FIG. 25. This situation is similar to fault Mode Id, where the robot cannot detect these types of loads with the robot, so other mitigations may be implemented as described above in Id. There is another scenario where these two loads could be applied to the body, since the endoscope and overtube were in an unpredictable pose prior to this faulted state. If the user performed a retroflex maneuver and the endoscope was sitting in a retroflex pose when this fault occurred, then the bending section would instead be pushing against two opposing sides of the same lumen space within the colon, as shown in FIG. 34.

[0257] Looking closer at this situation, when the fault has just occurred the first load that is concerning is the load of the restorative bending moment on the bending section of the device pushing against the lumen walls. The bending section on the device may be stiffer than a manual colonoscope, so it will exert a higher load on the colon walls than the manual colonoscope would in the exact same situation. The bending section of the robotic endoscope for this particular example may exert twice the loads on the colon wall in the same situation as the manual colonoscope. However, this load is not very high, so it is possible that it is not high enough to do damage to the colon wall as is. Another test was performed in which therobotic endoscope hooked up to the robot was in a retroflex in a section of porcine colon, and three different methods of straightening the bending section forcefully were attempted. In test 1, the robot was fully powered on and holding retroflex pose, removed the endoscope handle from the splines to remove the torque on the pulleys and therefore remove the tension on the cables. Only the friction of the cables in the coil pipes and around the pulleys was still present. Then pulled back on the handle manually to pull the endoscope out of the retroflex pose into a straight pose and out of the colon. In test 2, the robot was fully powered on and holding retroflex pose, hit the STO button to induce a release of tension on the cables. Only the friction of the cables in the coil pipes and around the pulleys and the friction in the gearing of the motors was still present. In test 3, the robot was fully powered on and holding retroflex pose, hold down the neutralize steer button to force the endoscope to drive into a straightened pose. Not only released the tension on the cables holding the retroflex pose but actively pulling the bending section into a straight pose with the opposing cables. Tests 1 (remove endoscope handle) and 3 (Neutralize steer) were performed in both a thicker section of porcine tissue and a thinner section. For each test, the results showed the before and after pose of the endoscope for each test. In all three tests there was no overtube present, and the handles were still attached to the endoscopes the entire time. In all three tests, there were no perforations from manual inspection of the tissue, and in none of the tests did removal of the endoscope cause perforations. Test 3 for the thin tissue was the only test in which the endoscope completely transitioned out of the retroflex pose without the user withdrawing the scope at all. Although all three tests suggested that the device would not cause damage in this situation, this test does not take into account other types of damage besides perforation and neither does it take into account the differences between porcine colon tissue and human colon tissue. In order to address the first issue, another test was performed on a live pig colon. This way, the robot would be able to detect if any damage occurred on the colon wall such as bleeding or bruising, which can’t be seen in the dead porcine tissue. The retroflexing test procedure included performing a retroflex in the same manner as a normal colonoscope. Once retroflex was achieved, the surrounding area was examined for damage to the tissue walls from getting into the pose, rotating to visualize the entire area, insert / retract some to visualize more sections of the wall. The retroflexed was then undone, in reverse, and the area was fully examined. After examining all regions of the colon that could have been affected by the retroflex maneuver, the no damaged was found.2c) While steering: Fbody5, Fbody6, Fbody7

[0258] Looking at Fbody5, Fbody6, and Fbody7 when the robot is steering, the scenario in which the device might experience these loads is when the bending section is not fullyexposed from the overtube, and there are loads on that section along the device, as shown in FIG. 26. This situation is similar to fault mode 2b, since the robot cannot steer with the bending section then the amount of exposed endoscope from the overtube is irrelevant, and the system can use the same approach as in 2b.2e) While steering: Fbody2

[0259] Looking at Fbody2, Fbody5, and Fbody6 when the robot is steering, the scenario in which the device might experience these loads is when hooked around a bend and continuing to pull the devices back, as shown in FIG. 27. Because the user does not have the ability to steer the endoscope after a fault, this load looks exactly the same as in situation fault mode 2a and can share the same approach to maintain the load on the patient within or below a desired target range or threshold.2f) While steering: Fbody4 and Fbody8

[0260] Looking at Fbody4 and Fbody8 when the robot is steering, the scenario in which the device might experience these loads is when the flexible proximal body of the nested pair is pushed around a bend in the colon, and the colon experiences the normal load from the restorative bending stiffness of the nested pair as it tries to push back into a straight pose, as shown in FIG. 29. Because the user does not have the ability to steer the endoscope after a fault, this load looks exactly the same as in situation fault mode 1c and can share the same approach to maintain the load on the patient within or below a desired target range or threshold.2g) While steering: Fbody9 and FbodylO

[0261] Looking at Fbody9 and FbodylO when the robot is steering, the scenario in which the device might experience these loads is when there is a shear force on colon walls when withdrawing, or when pulling back on a loop with too much force, as shown below. These loads would be the most common during reductions. This is illustrated in FIG. 30. Because the user does not have the ability to steer the endoscope after a fault, this load looks exactly the same as in situation Fault Mode la and can share the same approach to maintain the load on the patient within or below a desired target range or threshold.

[0262] For the fault scenario, the torques could be detected by the user in the same way that they would in a manual procedure, or to be even more conservative, they can simply not torque the device while they remove it since they do not need to perform a reduction. In general the torque load acting on the patient may be estimated in the same manner as the force load described herein. Torque sensing may be derived from the current applied to the motors driving rotation of the first (e.g., overtube) and / or second (e.g., endoscope) elongatemembers. In some cases only one of the two members may be driven in rotation (e.g., just the endoscope).Methods for Worse Case Faulted State

[0263] Putting all of this information together, two tables (table 6 and table 7) can be created, and for each load it can describe what scenario may cause that load and what the mitigation technique is for that scenario, again in reference to FIG. 16.Table 6: fault scenarios when not steeringTable 7: fault scenarios when steering

[0264] By filling out the technique for each load, these methods or techniques can be applied to the corresponding cases in the Motion Situations Matrix.Worst Case Faulted State Approaches to Use

[0265] The matched technique or approach to each load on the device are enumerated in table 8, below, showing a matrix of situations for the worst case fault states:Table 8: matrix of situations for the fault states

[0266] Because there is no ability for the robot to detect loads or create motion in this faulted situation, the primary approaches or techniques to reduce or maintain the applied loads may include training the user to remove the devices safely and / or design the device to be safe in these scenarios, as described herein.Investigation of Motion Situation: intubating mode

[0267] In some cases the overtube is rigid, and the endoscope is flexible. Steering is enabled. The endoscope can move either direction along insertion axis. The endoscope can roll, and the overtube cannot. While in intubation mode on the robot, it again should be looked at the types of loads that the system could be exerting onto the colon. The loading location on the endoscope will be the same as in previous sections, shown in FIG. 16, however the types of motion and the rigidization situation are different, therefore it must be looked at how to limit these loads differently.

[0268] For example, table 9 outlines these different forces and loads in the different situations:Table 9 la) Not steering: Fbody2. Fbody5. Fbody6. Ftipl. Ftip2

[0269] This situation should be examined in the same way as in withdrawing mode la again. In order to understand how the robot might detect these loads, it first should be looked at how they would detect similar loads with a manual colonoscope. The loading scenario can be classified with a normal colonoscope as either sliding or stretching. In sliding, the colonoscope is progressing along the tissue lumen, and the loads that it experiences are the sliding friction and the load at the tip. In stretching, the colonoscope is not sliding along the tissue, is experiencing static frictional loads keeping it from progressing, and is now stretching the tissue like a spring. A typical colonoscope allows the user to only detect loads at the handle in either of these situations. The endoscopist will limit the handle loads to the same threshold regardless of if the system is in the sliding or stretching condition (or a combination).

[0270] Recall FIG. 17. In these diagrams, the value C is the only load that the endoscopist has access to. In neither the sliding nor the stretching situation can they detect each of the loads exerted at different points on the colon separately and individually, they can only limit what load they push on the colonoscope based on the value of C. For the robotic endoscope, the robot detects the loads in the same location as an endoscopist with a typical colonoscope wo the value of C. The loading scenario can be classified with a robotic endoscope as either sliding or stretching the same way as before, but this time the overtube is what the endoscope is sliding against in sliding, and it is what is mostly supporting the endoscope loads in stretching. In the sliding case, the robotic endoscope is progressing along the overtube length, and the loads that it experiences are the sliding friction along with the load at the exposed tip. In the stretching case, the robotic endoscope is not sliding along the overtube, is experiencing static frictional loads keeping it from progressing, and is now stretching and deforming the overtube like a spring. Now to look at if the loads that the robot is detecting encompass at least the same forces on the body that the colonoscope detects, in addition to the loads it experiences from the overtube. Failing that, the loads that the body experiences are less than or equal to the loads it would experience from a typical colonoscope in the same scenario. Thus, the robot is safer or as safe as a typical colonoscope would be in the same situation.

[0271] For the case in intubation mode la, the loads that the endoscope and overtube experience in this situation are sliding forces. The first thing to do is say that when in intubating mode, the overtube is stationary and not driven at all by the robot, so it will not be sliding relative to the colon tissue, and therefore not be experiencing any sliding forces in this mode. As for the endoscope, the free body diagram can be drawn below. The loads that the endoscope is experiencing while sliding can either be exerted on the overtube or on the colon walls, because some of it is exposed and some of it is not (since a large portion of it iscovered by the overtube). Thus, these methods may determine if the robot detects the same load that a colonoscope would detect. Re is measuring Ftip to the same extent that the colonoscope value C measures Ftip. It is also measuring the frictional loads to the same extent, though in this case they are not imparted on the body. In the first case, the frictional force on the body does not exist since the overtube provides that normal force, so the total load on the body is less (nonexistent). In the second case, there is some frictional load on the body, but the surface area over which it occurs is much smaller than with a typical colonoscope, so the summed frictional load is less.

[0272] In order to be sure that this math holds up and the tip load is completely transmitted down the length of the endoscope body as is suggested, the robotic endoscope handle was assessed to detect a load at the tip in a variety of tortuosity. For example, the nested set was wrapped around a standard radius of curvature (4”) which is representative of colon tortuosity curves (defined by endoscopy team), and rigidized to hold it in place, and the support used to create the curve was removed; frictional loads on the endoscope from the overtube (without any external loads) were measured as a baseline, and an external force gauge was placed to elastically react against the endoscope motion (attached to a spring so the input force is a ramp rather than a step function) in front of the tip of the endoscope, and this process was repeated with the endoscope impacting the force gauge each time it moves forward. This test was repeated for different tortuosity (e.g., 90 degrees in FIGS. 36A-36B, 180 degrees in FIGS. 37A-37B, 270 degrees in FIGS. 38A-38B, 360 degrees in FIGS. 39A- 39B, 450 degrees in FIGS. 40A-40B), the motion of the endoscope throughout the test was plotted as shown in each of FIGS. 36B-40B (top). This motion was identical whether the endoscope was impacting the external load cell or not. The second plot (FIGS. 36B-40B, middle) shows an overlay of the force readings from the tests with and without the impact (with the exception of a few of the tests, which are labelled appropriately) along with the load reading from the external force gauge. The third graph in each set (FIGS. 36B-40B, bottom) shows the calculated external force reading that the endoscope reads, which is calculated by subtracting the forces read when the endoscope did not impact the external force gauge from the force read when it did impact the external force gauge, effectively removing the loads that were purely from the overtube and sliding on the surface. In the last graph for each test, compare to see if the entire external load from the force gauge was read by the load cell at the handle of the endoscope. This is may not be the algorithm that is proposed to use for this situation, but rather a way to visually compare and verify if loads are transmitted down the length of the endoscope the way they are thought to be from the calculations. It can be seen that the comparison for all of the different tortuosity shows that the robot does in fact read theentire load at the tip of the endoscope via the handle, and more. The reason the robot reads a higher load is due to the additional friction from the other device, and this additional load only serves to make the detection method more conservative. This test does not capture frictional load is in the opposite direction from the external load at the tip and external loads on the overtube cases, which can translate through the devices back to the handle.

[0273] FIG. 41 shows an example of how the frictional load from the overtube may either add to the false positive or detract from how well the robot can detect the loads on the endoscope. In this example, if the limit were 20N, the robot would not report a positive. If the limit were ION the robot would report a positive. Here, the frictional load simply added to the force that the robot was measuring on the endoscope because it was acting in the same direction as the external load on the endoscope. The robot has conservatively measured the load on the colon from the endoscope and did not have a false positive. As for the overtube if the force limit were 5N, the system would not report a positive from the overtube, despite the true 5N load on the overtube, due to the direction of the friction on the overtube. The key here is that the overtube is not moving in this scenario, and if it is not moving it is not actively exerting a load on the colon, so there is no concern of this load becoming any higher or lower than what it is now. As for the 5N that it experiences now, it had to have been moving in order to get into that state, and when it was moving the robot would have been able to detect the load on the overtube at that time (see the analysis for the overtube motion later on in the shape copy mode situation, below). So, at the time that the overtube was exerting that 5N load while it was moving, the robot would have been detecting the load responding to how high it got at that time. There is no concern about the overtube load now that it is stationary. When the friction acts in the opposite direction on the endoscope, the endoscope is moving. The example shown in FIG. 42 describes this situation. In this example, if the limit were 20N, the robot would not report a positive. If the limit were ION the robot would not have reported a false positive. The frictional load in the opposite direction of the load the robot wanted to measure prevented the robot from seeing the entire load on the colon. Next to be looked at are all the possible situations in which this could happen and see what the system could do in each one. There are 8 possible loading and motion scenarios the system can be in when the endoscope is flexible and the overtube is rigid, graphically shown in FIG. 43. FIG. 44 illustrates examples of the loads detected by the endoscope in each of these situations. There are 4 situations out of the 8 where the system is not correctly detecting the load, as shown in examples 2, 3, 6, and 7. The load from the body can be exerted in the opposite direction of motion of the endoscope because the colon tissue is not only exerting a frictional force on the endoscope, but also a spring force. So, there is a finite region where the force from this springcan be applied in the same direction as the motion of the unit. This is illustrated in FIG. 45. In some examples, e.g., scenario 2 in FIGS. 43 and 44, the overtube has performed a retraction, causing a load on it in the +z direction while the endoscope is hooked around a comer, also causing a load in the +z direction on the endoscope. The user then moves the endoscope forward. In some cases (e.g., scenario 3 in FIGS. 43 and 44), the overtube has performed a retraction, causing a load on it in the +z direction while the endoscope is pushing against a colon wall, causing a load on the endoscope in the -z direction. The user then moves the endoscope backward. In some cases, e.g., scenario 6 in FIGS. 43 and 44, the overtube has performed an advancement, causing a load on it in the -z direction while the endoscope is hooked around a corner, also causing a load in the +z direction on the endoscope. The user then moves the endoscope forward. In some cases, e.g., scenario 7 in FIGS. 43 and 44, the overtube has performed an advancement, causing a load on it in the -z direction while the endoscope is pushing against a colon wall, causing a load on the endoscope in the -z direction. The user then moves the endoscope backward. These situations are realistic; for every one of these scenarios, the endoscope is moving in a direction that is decreasing the spring force from the tissue, because it is moving away from where the load is being applied. So, just as described above for the overtube, to have reached that load that it is experiencing in the first place, the endoscope had to be moving in the other direction, increasing that load first. In that prelude situation, the friction was acting in the opposite direction of the motion, and so, at that time, in the same direction as the external load. And it was shown that in situations where the loads were facing the same direction, the robot conservatively measures that load. Essentially, each situation where the robot cannot measure the load conservatively is precluded by a situation in which the load was conservatively measured, and the load will not increase any more while in this edge case situation because it is always moving in a direction that will decrease the load on the colon. For the friction and the external load to be facing opposite directions, the system must be moving in such a way that it is relieving the load on the tissue.

[0274] Thus, in summary, when the manual colonoscope is sliding along the colon walls, the loads at the tip are fully transmitted back to the insertion point, where the endoscopist is holding it. The stretching forces of pushing against mesentery on the colon are also transmitted down the length to the insertion point, where they can be detected by the endoscopists hand. When the robotic endoscope is sliding inside the rigid overtube, the loads at the tip are fully transmitted back down through to the insertion point the same way, where the force sensor can measure it. The frictional forces of sliding along both the overtube inner wall and the colon wall on the exposed portion are also transmitted down the length to theinsertion point. Frictional losses prevent the robot from measuring the load perfectly accurately, but in analyzing how the losses affect the measured load, It can be seen that in half of the situations the frictional losses cause the robot to detect a higher load than the patient actually experiences, which makes the measurement conservative by creating a false positive instead of a false negative, and in the other half when the friction causes the robot to measure a lower load than what he patient feels, the robot would have measured the conservative load prior to that situation and reacted to it at the time, or otherwise are decreasing the load due to the direction the system is moving relative to the load direction. The sliding load on the overtube in this mode will be the opposite and will read a less conservative load whenever the endoscope is reading a more conservative load and vice versa. However, the overtube is not moving at this time, and so will not exert a higher load on the colon than it had exerted previously, so the robot is not as concerned with monitoring that load. It is still desired to continue to monitor it however in case other effects come into play such as the patient moving. lb) Not steering: Fbodyl Fbody4

[0275] For these loads on the system, refer to the previous analysis in Intubation Mode la and this time look at the stretching case. First, to look again at how the stretching forces resolve with a manual colonoscope, as described in FIG. 18. Next look at how these loads occur when the robot is navigating with the robotic endoscope. The key difference here is that the robotic endoscope again is affected by not only the body loads, but also the loads from the overtube. So, the free body diagram of the endoscope will look exactly the same, but where those loads are coming from is different. The static equilibrium equations can be solved the same way on this free body diagram, as shown in FIG. 46. FIG. 46 also shows equations for what is creating the external load for the endoscope, which includes contributions from both the colon and from the overtube. These equations can be plugged into the static equilibrium equations, as shown in FIG. 47. The robot detects the same load that a colonoscope would detect and the load is exerted on the body for a given input force less than or equal to the manual colonoscope in the same situation. This is shown in FIG 48.

[0276] Next the case where the system does not have the body forces to contend with, just the overtube itself is examined. For this analysis, the focus was on the loads only in the z- direction, as shown in FIG. 49

[0277] Based on the free body diagrams, breaking out the overtube and body forces as separate inputs, it is apparent that the load exerted on the body for a given input force is less than or equal to the manual colonoscope in the same situation, as shown in FIG. 50 and 51. This can be summarized by looking at an even simpler example, showing that the overtube inintubating mode is only ever an additional support for the endoscope, so that the load the robot exerts on the body is less for the same input load, as shown in FIG. 52. When the manual colonoscope is stretching the colon walls, the loads on the body are complex and highly dependent on the shape of the device, where and if it is buckling, and where it is contacting the colon walls. Many of the loads cancel each other out internally. The endoscopist however is still simply limiting the force exerted by the colonoscope at the insertion point. When the robotic endoscope is stretching the colon walls, it is because the overtube is not perfectly rigid and stretches some. The robotic endoscope is in the same situation as the manual colonoscope. The presence of the rigid and stationary overtube does not increase the loads that the patient experiences in this situation, and in fact lessens these loads by supporting the endoscope force instead of allowing it to push fully on the colon walls. Stretching the rigid overtube won’t cause the system to exert more force on the colon, it will only lessen how much of the force from the endoscope is exerted on the colon.

[0278] Therefore, the robotic endoscope detects the loads in the same way that the manual colonoscope does under these conditions, so can be monitored and limited in the same way. It will even be more conservative due to the fact that the rigid overtube lessens the amount of stretching force the endoscope is exerting on the colon walls directly.1c) Not steering: Fbody3

[0279] Looking at Fbody3 when the robot is not steering, as shown in FIG. 23, the scenario in which the device might experience these loads is if the tip of the endoscope gets wedged around a comer or flexure. This situation is similar to withdrawing mode Id, where The robot cannot detect this load but can reduce it by ensuring that the endoscopist is maintaining a view of the lumen as much as possible and making sure that the length of thestiffer bending section is not so long that it will force open tortuous paths that are much more proximal to what the user can see.2a Steering: Ftipl, Ftip2, Fbody9, FbodylO

[0280] Looking at Ftipl, Ftip2, Fbody9, and FbodylO when the robot is steering, the scenario in which the device might experience these loads is if the endoscope is inserting into tissue, either while articulated or not, or if the overtube is holding a load on the colon from a previous motion, as illustrated in FIGS. 35A and 35B. No new loads occur from the overtube since in this motion situation, the overtube is stationary. This situation is similar to intubating mode la, where a load on the endoscope in this way is fully transmitted back through the handle, and therfore fully detectable by the robot.2b) Steering: Fbody4, Fbody8

[0281] Looking at Fbody4 and Fbody8 when the robot is steering, the scenario in which the device might experience these loads is if the endoscope is inserting into tissue, either while articulated or not, and causing the overtube and the tissue to stretch around it to accommodate the motion, instead of sliding along the colon wall, as shown in FIG. 46. This situation is similar to intubating mode lb, where a load on the colon in this situation is no different from the load a manual colonoscope would see in the same situation. The only difference with thenested system, is that the load is partially carried by the overtube, so the load on the colon would be less than or equal to that of a manual colonoscope pushing with the same load.2c) Steering: FbodyL Fbody2, Fbody3

[0282] Looking at Fbody 1, Fbody2 and Fbody3when the robot is steering, the scenario in which the device might experience these loads is during normal navigation, articulating the bending section to maneuver through the tissue. This situation is similar to withdrawing mode 2b, as shown in FIG. 24, where the robot can minimize this load by carefully designing the endoscope tip as well as enforce training on users to maintain a view of the lumen as much as possible to prevent and reduce this side loading. One unique maneuver in this motion situation, however, is the retroflex maneuver. Retroflexing should only be allowed with the robot during the intubation mode. To understand the loading scenario when retroflexing, first look at how physicians create and maintain a retroflex with a manual colonoscope.Manual Colonoscope Retroflexing:

[0283] When looking at how the loads on the colon are distributed, the largest load is due to the shear force on the colon wall used to force the tip of the bending section over. This is illustrated in FIG. 53, showing retroflexing. Because this is a shear force along the insertion axis of the colonoscope, the load is fully transmitted back down through to the handle, or the insertion point of the colonoscope, as shown in FIG. 54. The physician can therefore feel this load with their hand and respond to it.

[0284] To get into the retroflex with the robot, there are a few options of how the robot could maneuver the articulating section. First, the robot could simply articulate the bending section to get into the retroflex shape since the cables can pull on the bending section with a higher force than a manual colonoscope can. Second, the robot could maneuver the tip in the exact same way that the manual device is maneuvered and try to minimize the shear force on the colon wall. Third, the robot could attempt to minimize the swept radius, r, in order to minimize both.Case 1: Simple Sweep

[0285] FIG. 55A illustrates a simple sweep maneuver. It can be seen how with this maneuver, the robotic endoscope tip is sweeping across the tissue wall, as well as pushing it out radially. So, there is both a shear force created, and a radial force created, as shown in FIG. 55B. Due to the rigidization layer, the bending stiffness of the robotic endoscope is larger than that of a manual colonoscope, as it was shown in Fault Scenario 2b. The tendons (steering the distal end region of the scope) can pull on the bending section with much higher loads than the manual colonoscope can, therefore the shear force on the wall would be even greater than if a manual colonoscope were performing this maneuver. Between that and creating an equally large radial force assuming the bending section mechanically creates the same swept radius r, this strategy creates higher loads than a manual colonoscope would.Case 2: Hold Tip Position

[0286] FIG. 56A illustrates holding the tip position. In this procedure, the robot would hold the tip position relative to the colon wall in the insertion direction such that the device does not create a shear force on the wall. If there are zero motion in this insertion direction of the tip of the endoscope, the device would create zero load along this axis on the wall (note: this does not mean zero insertion of the endoscope shaft, this means compensating for the tip motion as it articulates with the insertion axis), as shown in FIG. 56B. Furthermore, all of the radial load on the colon reacts through the tendon forces, not through the insertion axis. This solves the issue of shear force, but assuming there are the same or comparable bending section mechanics to a manual colonoscope, the swept radius r2 does not change, and therefore the radial force on the wall of the colon is the same as with a manual colonoscope. This load is undetectable by the insertion axis load sensing, both for the robot and for the manual colonoscope. While this would solve some of the problems, the system would need to enforce that the bending section mechanical structure should be almost the same as a manual colonoscope. Furthermore, it would create a situation where the camera does not see any sliding of the colon wall past the video, which is a key indicator for the physician of if the retroflex will be successful without injury.Case 3: Unfurling and Furling

[0287] The last technique, unfurling and furling, shown in FIG. 57A, involves using the rigid overtube of the nested system in order to mechanically limit how many of the bending section links are able to bend at a given time during the maneuver. By turning each link to its maximum bend prior to bending the next section, the device is able to maintain a constant radius or bend throughout the entire retroflex process. By maintaining this tighter radius throughout the entire maneuver, the radius r2 now becomes equal to the final radius rl andreduces the potential for load in both the shear force and radial force directions, as shown in FIG. 57B. The device would only create no load on the colon in this idealized example; more likely the device will still contact the colon wall, but due to the minimized bend radius the load on the wall will be significantly reduced. The swept radius r is substantially smaller for case 3 (unfurling) as compared to Cases 1 and 2 (sweeping)

[0288] Due to the fact that this maneuver only eliminates colon loads in a perfect colon diameter, but colon diameters vary greatly from person to person and also within the same individual at different locations, it is described herein is an algorithm that combines aspects of both Case 2 and Case 3 to ensure that loads in the most likely directions and that can cause the most damage are minimized. A test using a nested rigidizing system in a testbed (measuring real-time force and torque) was performed to test the loading results from each type of maneuver. The results are in FIG. 58. The free body diagram of the robotic endoscope versus the manual colonoscope show how loading in the same exact mechanical maneuver situation would exert loads on the colon.

[0289] It can be seen from how the majority of the loads are reacted through the tendons on the robotic endoscope as opposed to through the insertion axis that the robot will be exerting less load from inserting and potentially more load from shear depending on the method of retroflex. However, for all cases, the robotic retroflex will not see as much load along the measured insertion axis. This means that in testing and with measured forces on the robotic handles for the insertion axis, the robot will not be sensing all the loads, because neither one of these can measure the tendon force or the radial force, only the insertion force. So, there are to rely on the mechanical analysis to ensure that those other loads will be lower.

[0290] The results from the testing are shown in FIGS. 59A-59C and 60. It should be noted that for Case 1, using only the articulation of the robotic endoscope did not allow the endoscope to complete the retroflex, so an insertion command followed the articulation command in order to complete the maneuver. The average insertion force for a retroflex found in this example was approximately 12 N, giving a reference point for these magnitudes. FIGS. 59A-59C shows the force when getting into the retroflex using the robot performing the procedure to minimize the wall forces. FIG. 60 shows manual retroflexing, for comparison.

[0291] FIGS. 61A-61B show force when getting out of retroflexing using the robotic endoscope (case 2) performing the procedure to minimize the wall forces, and FIG. 62 shows the force for manual colonoscope operation. Even if the system is able to minimize these loads or make them comparable to the manual colonoscope, there is still an issue of being able to indicate to the user if they get too high. Unless the system can guarantee the loads willnot get too high in this situation, the physician still needs to have a way of knowing if the retroflex will cause a high load. With manual colonoscopes, if the physician attempts to retroflex in a section they can use the insertion loads they feel with their hands at the insertion point to regulate how high of a force to push with, since these loads directly correlate to the force of pushing the endoscope tip over to create the retroflex. If the load is too high, then they can back off the force or abort. However, there are just seen that on the robot, the device is not translating the same loads down to the insertion axis where the robot can measure the loads. Therefore, there are to rely instead upon other indicators of high force. Other ways they can tell if a force is high are looking at the camera image for tissue blanching, or watching to see how much the tissue slides across the image as they increase the insertion load. Both of these indicate that the angle that the endoscope is pointing to face the wall is an important metric, because they have to be able to see these things with the camera facing the colon wall. So, then the system can have a mechanical requirement on the endoscope that within a certain radius of bend of the endoscope, the camera must be able to see the colon wall in a nominal diameter colon, because otherwise the user will not be able to use the only mitigation left to them to prevent high retroflex forces.2d) Steering: Fbody5, Fbody6, Fbody7

[0292] Looking at Fbody5, Fbody6, and Fbody7 when the robot is steering, the scenario in which the device might experience these loads is if the endoscope is inserting into tissue and is articulating while it is not fully exposed from the overtube. This scenario differs from intubating mode 2b in that the endoscope is now muscling the overtube around to create stretching loads with the bending section. This scenario is very similar to withdrawing mode 2c, shown in FIG. 26, and the mitigations apply in the same way, where the team would need to train the physicians to maintain lumen view to minimize bending section loads on the colon walls. Furthermore, this situation would create lower forces than in withdrawing mode 2c, because the overtube is rigid and takes up part of the load from the bending section, preventing it from pushing on the colon wall as much.

[0293] By the same logic as with insertion forces, when the device is sliding while rolling, the torques at the tip, schematically illustrated in FIG. 63, will be fully transmitted to the insertion point for both manual colonoscope and robotic endoscope Also, by the same logic as with insertion forces, when the device is stretching the colon wall while rolling, the robotic endoscope will experience the same load that the manual colonoscope would feel given the same input torque, but the rigid overtube would partially relieve the colon wallfrom experiencing a portion of that torque. Therefore, for the same input torque, the colon will experience less it less with the robotic endoscope versus the manual colonoscope.

[0294] The endoscope and overtube were tested for torque by navigating to a cecum, performing a retroflex so that the bending section was fully exposed and would push on the walls in torque, then rotated. The torques on the endoscope and overtube were recorded (using a testbed to measure real-time force and torque) and at the robotic handles. It can be seen how the endoscope load follows the recorded load, both in the positive and negative directions, but has a higher magnitude which can be attributed to the sliding friction between the endoscope and overtube, as shown in FIG. 64, when rotating the endoscope in the cecum while retroflexed (intubating mode).Methods for Intubation

[0295] This information may be combined to create one or more tables that can describe (for each load) what scenario may cause that load and what the mitigation is for that scenario. Once more in reference to the force body diagrams shown in FIG. 16, tables 10 and 11 show scenarios for not steering and steering, respectively.Table 10: not steeringTable 11 : while steering

[0296] These methods and techniques can be applied to the corresponding boxes on the Motion Situations Matrix. The matched approach to each load on the device are enumerated in Table 12.Table 12: matrix of techniques to maintain the load on the patient within or below a desired target range or thresholdThe Intubation Mode Algorithm

[0297] For the unified algorithm when intubating, the minimum number of different techniques or methods may be used to keep it as simple as possible. Because some of these external loads are applied to the overtube and some are applied to the endoscope, the loads should be looked at and are read by both the endoscope handle and the overtube handle. If the robot monitored the net load between these two, the robot would not get the whole story because the friction between the devices could cause a true load on the colon to be lost. Thus, in order to maintain patient loads within within or below a desired target range or threshold, the robot needs to monitor the individual loads on the overtube and the endoscope separately, and limit the motions based on these values. This applies to both the insertion forces and the roll torques. This would conservatively cover all the situations listed above that it is possible to measure the loads in. For the unmeasurable loads listed above, the system is configured so that it won’t apply too high of a load on the patient, to prevent or limit the occurrence of these loads as much as possible.Investigation of Motion Situation: shape copy mode

[0298] During shape copying the endoscope is rigid, and overtube is flexible. Steering is disabled. Overtube can move either direction along insertion axis. Neither unit can roll. The loading location on the endoscope and overtube in this shape copying mode will be the same as in previous sections, however the types of motion and the rigidization situation are different, therefore the robot may limit these loads differently. Recall the force body diagrams in FIG. 16 and the groups discussed above when no steering (la-lc) and when steering (2a-2d), shown in Table 1, above. la) Fbody2, Fbody5, Fbody6, Ftipl, Ftip2

[0299] Looking at loads Fbody2, Fbody5, Fbody6, Ftipl, and Ftip2, these would occur whenever the overtube is contacting the colon wall while shape copying, due to frictional sliding. Endoscope tip forces could either be present or not at this time. This situation is to beexamined in the same way the robotic endoscope sliding in the rigid overtube was analyzed in intubating mode la. The same parallels can be drawn to the manual colonoscope in how the loads are transmitted back down the overtube to the handle.

[0300] When the manual colonoscope is sliding along the colon walls, the loads at the tip are fully transmitted back to the insertion point, where the endoscopist is holding it. This is illustrated in FIG. 65 A (and FIG. 17). The frictional forces of sliding along the colon are also transmitted down the length to the insertion point, where they can be detected by the endoscopists hand. When the robotic overtube is sliding along the colon walls, the loads along the body are fully transmitted back down through to the insertion point in the same way, where the force gauge can measure it, as shown in FIG. 65B (and FIG. 35 A). The frictional forces of sliding along both the overtube inner wall and the colon wall on the exposed portion are also transmitted down the length to the insertion point.

[0301] The robotic overtube detects the loads in the same way that the manual colonoscope does under these conditions, so it can be monitored and limited in the same way and may even be more conservative due to the fact that the endoscope supports the overtube, reducing the normal force on the colon wall therefore reducing the friction. lb) Fbodyl Fbody4

[0302] Looking at Fbodyl and Fbody4, these loads occur when the rigid endoscope is not quite strong enough to provide full support to the flexible overtube, allowing it to stretch out and push up against the mesentery, shown in FIG. 66. This situation parallels intubating mode lb, in that the stretching forces on the colon wall are also transmitted down to the handle in the same way that they would be on a manual colonoscope in the same situation. The rigid endoscope also provides support for the overtube so that it does not push against the colon walls with as much force as with a manual colonoscope, such that the load on the colon for the same insertion force on the handle would be at most equal to but more likely less than the load felt by the colonoscope. lc) Fbody3

[0303] Looking at Fbody3, this load occurs when the rigid bending section of the endoscope is not quite strong enough to provide full support to the flexible overtube, allowing it to stretch out and push up against the mesentery, shown in FIG. 67. Because the endoscope is incapable of steering during this mode, there is no difference between this and shape copy mode lb.2a) Ftipl, Ftip2, Fbody9, FbodylO

[0304] Looking at loads Ftipl, Ftip2, Fbody9, and FbodylO, ideally exact comparisons could be drawn between this situation and shape copy mode lb. However, in this situation therobot has an articulated bending section that it has to shape copy over with the overtube. This specific scenario causes particularly high frictional loads between the two devices, as shown in FIG. 68, showing loads Ro and Reduring a shape copy of an increasing radius of curvature bending section. It can be seen how as the articulation of the endoscope increases, the friction between the two devices gets higher, up to 40N of load. This is because the act of shape copying has the overtube not only fighting the endoscope friction against it, but also its own bending stiffness. The overtube must push hard enough as it slides to bend its tip into the same articulation as the endoscope, fighting against the bending stiffness of the overtube. When looking at how this extreme high friction affects the loads read by the robot overall, it can be seen that these high friction events dominate the loads measured. In these two runs through an alpha loop (FIG. 69A) and an N loop (FIG. 69B) in the realistic tissue model, the highest loads are shown highlighted. All other loads during this run were less than half of some of the peaks. FIGS. 69A and 69B show endoscope and overtube forces during two runs on RTM showing high spikes during shape copy. If this paralleled intubating mode la, then the robot would want to look at each the endoscope and overtube loads separately and individually in order to distinguish which loads come from the endoscope and which ones come from the overtube. But if the robot uses that method, then it may constantly trigger a false positive value every time. Next it will be looked at where this load plays a role mathematically.

[0305] In the analysis shown in FIG. 70, it can be seen that the frictional component of this equation is present and it is known that this is the part that is dominating the reading since it is much greater than any of the other loads. It can be seen in the equations that if Ftip were equal to 0, then one should be able to substitute in the equation for Re so that one can cancel the loads between the endoscope and overtube and get a reading that still tells the robot the load on the patient. However, this assumes that Ftip on the endoscope is equal to zero, which in many cases it is not. This analysis was validated in several tests. For example, a load on the overtube was created while it was shape copying with an external force gauge. This is illustrated in FIG. 71. Due to the articulated bending section, there is a high frictional load between the endoscope and overtube, shown in the second (middle, FIG. 71) graph. But in this plot, it can be seen how the values are nearly equal and opposite on the endoscope and overtube, because they are primarily creating this load on each other, not on the external gauge. Next, take the signed sum of the measurement on the endoscope handle and the overtube handle 7101 and compare that value to the external load on the overtube 7103 in the last plot. The shapes are nearly identical. Because there was no load on the endoscope tip, one can extract the external load from the high measurements quite accurately. In thisexample, the offset may be an artifact of the calibration. Thus, the robot can extract an external load when there is no endoscope tip load. A similar outcome is shown if there is an endoscope tip load. A force creating a load on the overtube also creates a load on the endoscope at the same time. This is shown in FIG. 72. It can be seen in this test that now that there are two loads, one on each device, neither one matches the signed sum of the load between the endoscope and the overtube. But if one adds the external load on the endoscope to the external load on the overtube, it can be seen that each of the devices is in fact still transmitting the load fully to the sensor, the measurements are just not able to separate them. So, it is clear that all loads that are present are accounted for. The output has the same results, even in high tortuosity, as shown in FIG. 73. The robot does not consider the loads on the endoscope and overtube separately but instead may use the net load in this situation. This is illustrated in FIG. 74. If the system does not have a high frictional component between the two devices, the system would be in the situation shown in FIG. 74. In this case, because there are not high loads between the two devices, the robot can use the exact same algorithm described in intubating mode la. However, in some cases, this may result in errors, as shown in FIG. 75. The outcome of taking the signed sum of the measurement at the two handles may therefore be examined. In this situation, the robot may not able to detect the load separately but may successfully detect a high load on the patient and significantly reduced inaccuracies, though it may still be off by the exact amount of load on the endoscope tip. This may be because the endoscope tip load combined with the overtube load, since the external load on the endoscope and overtube were acting in the same direction along the insertion axis. This is shown in FIG. 76. If there are external loads on the endoscope and the overtube acting in opposite directions along the insertion axis, as shown in FIG. 77, the robot may not report the load on the patient accurately enough to hit the threshold and warn the physician of the high load. It could in theory try to capture that load from the endoscope before the shape copy occurs, but in practice this has proven difficult, and the imperfect rigidization of the endoscope means that external loads on it will change throughout the shape copy, so even if the robot did capture the measurement on the endoscope before doing the shape copy, it would no longer be accurate after the devices start moving against each other and muscling the rigid shape into the colon walls. So instead, the robot may be configured to look at which loading conditions cause these two situations, how practical it is to assume the system might be in those loading conditions and analyze how to address each of them.

[0306] There are 8 possible loading and motion scenarios the system can be in when the overtube is flexible and the endoscope is rigid, illustrated in FIG 78 (similar to FIG. 43). Now the net load in each of these situations may be examined to see how it compares to the actualload on the patient in those situations. It can be seen that half of the 8 scenarios result in a load that is conservative in measuring the actual patient load because the endoscope and overtube loads do not cancel each other out. Unsurprisingly, these are all the situations in which the loads are felt in the same direction as each other. These are shown in scenarios 1, 2, 7 and 8. Scenario 7 is the most common scenario. If the net load is greater than or equal to the two loads felt by the body, the system may successfully detect a conservative measurement of what the colon feels like. Scenarios 3-6 (shown in detail in FIG. 79) can be examined to assess the practicality of being in those situations while driving with the robot, and what, if anything, the robot can do in these situations specifically. This is illustrated in FIG. 17. In Scenario / situation 3, the load on the endoscope may be detected prior to this situation and determined safe. The load on the overtube may be detected prior to this situation and determined safe. This motion of the overtube will only ever decrease the load felt by the patient. If the overtube moves far enough to back to swap the sign of the load to negative, then the system is no longer in situation 3.

[0307] In scenario 4, the net force calculation may not be used, but rather the individual force on each unit may be used. If the friction is too high, this may cause a false positive. However, this situation is uncommon. The robot may be configured to detect what situation it is in and can alert the use of the likely false positive and direct the user how to get out of this situation. Because retraction of the overtube is a lower friction event than advancement, this situation may not always yield false positives.

[0308] In Scenario 5, the net force calculation may not be used, but instead the individual force on each unit may be used. If the friction is too high, it will cause a false positive. Because this situation does not happen often, it will not interrupt workflow too much. The robot may be configured to detect this scenario and can direct the user how to get out of it if the false positive impedes progress.

[0309] In Scenario 6, the load on the endoscope was detected prior to this situation and determined safe. The load on the overtube was detected prior to this situation and determined safe. This motion of the overtube will only ever decrease the load felt by the patient. If the overtube moves far enough to back to swap the sign of the load to negative, then system is no longer in situation 6.

[0310] Thus, the system may determine each of these situations and can be configured to act differently based on this determination, as described above.2b) Fbody4, Fbody8

[0311] Looking at Fbody4 and Fbody8, these loads occur when the rigid endoscope is not quite strong enough to provide full support to the flexible overtube, allowing it to stretch outand push up against the mesentery. This is shown in FIG. 66. This situation parallels shape copy mode lb.2c) FbodyL Fbody2, Fbody3

[0312] Looking at Fbody 1, Fbody2, and Fbody3, this load occurs when the rigid bending section of the endoscope is not quite strong enough to provide full support to the flexible overtube, allowing it to stretch out and push up against the mesentery, as shown in FIG. 67. Because the endoscope may not be able to steer during this mode, there is no difference between this and shape copy mode lb.2d) Fbody5, Fbody6, Fbody7

[0313] Looking at Fbody4 and Fbody8, these loads occur when the rigid endoscope is not quite strong enough to provide full support to the flexible overtube, allowing it to stretch out and push up against the mesentery, as shown in FIG. 66. This situation parallels shape copy mode lb.Methods and Techniques for Shape Copy

[0314] Putting all of this information together, two tables can be created, Table 14 and Table 15, and for each load it can describe what scenario may cause that load and what, if any techniques or mitigation may be used for that scenario in order to maintain the load on the patient wihtin or below a desired target range or threshold. Referencing the force body diagrams in FIG. 16, table 14 shows scenarios in which the apparatus is not being steered, and table 15 shows scenarios when the robot is being steered.Table 14: not steeringTable 15: while steering

[0315] By filling out the methods or techniques for each load, these methods can be applied to the Motion Situations Matrix. The matched safety approach to each load on the device are enumerated in Table 16, below.Table 16: matrix of techniques to maintain the load on the patient within or below a desired target range or thresholdThe shape copy mode

[0316] A unified technique may be used to avoid exceeding loads on the patient based on the information described above. For example, when performing a shape copy, the minimum number of different methods or techniques to maintain the load on the patient within or below a desired target range or threshold may be used to keep it as simple as possible. However, a single technique may not be advisable, because it may have the issue of high internal forces requiring the system to sometimes use one method and sometimes use another depending on the loading situation. Instead, these systems and apparatuses may use an algorithm that switches between looking at the individual load on the endoscope and overtube and looking at the net load between the two. This may be based on whether or not the loads on the endoscope and overtube are opposing each other or not.Investigation of Motion Situation: Both Units are Rigid, Unmoving

[0317] For example, in some cases both the overtube and the endoscope are rigidized (e.g., as part of the sequence of steps in performing a shape copy) and neither is moving along any axis. While in this mode (e.g., “Both Units Rigid Mode”) on the robot, the types of loads that the system could be exerting onto the colon may be examined. The loading location on the endoscope and overtube may be the same as in previous sections, however the types of motion and the rigidization situation may be different, therefore the robot may look at how to limit these loads differently. For this situation, the loads can be grouped differently. Neither unit is moving, so the system no longer has to worry about steering, and there are no insertion axis loads. While the robot isn’t steering the device, it can still be in a situation where the bending section is articulated. Recall the force body diagrams in FIG. 16 and corresponding groups (in this case, just group la is relevant). Looking at Fbody2(not steering), Fbody5, Fbody6, Fbody9, FbodylO, Ftipl, Ftip2, Fbodyl, Fbody2 (steering), Fbody3, Fbody4, Fbody5, Fbody6, Fbody7, and Fbody8, the scenario in which the robot might experience these loads is when the endoscope or overtube is moving along the insertion axis, or along it’s shaft, or if there are any lateral loads on the colon walls, as shown schematically in FIGS. 29 and 30. Because both devices are rigid in this state, they are not moving along this axis at all, so these loads will not change from what they were previously. Whichever algorithm was detecting these loads at the time they were moving will have caught if anything was too high. Furthermore, the devices do not move at all when rigid in general, so any lateral loads on the colon will also be unchanging, and there is no need to detect them.Methods for Both Units Ri id

[0318] Putting all of this information together, a table can be created, and for each load it can describe what scenario may cause that load and what the mitigation is for that scenario.Table 17

[0319] These methods and / or techniques to maintain the load on the patient within or below a desired target range or threshold can be applied to the corresponding motion situations matrix, and the matched approach to each load on the device are shown in table 18.Table 18: matrix of techniques to maintain the load on the patient within or below a desired target range or thresholdBoth Units Rigid Mode Algorithm

[0320] For the unified algorithm when both devices are rigid, it has been shown that the robot does not need to monitor loads, the robot may optionally monitor the endoscope and overtube forces and torques separately in this mode. The mitigation in this mode may be the mechanical properties of the endoscope and overtube.Investigation of Motion Situation: Transitioning Rigidizatiom Unmoving

[0321] In some cases, either the endoscope is switching from flexible to rigid, or the overtube is switching from flexible to rigid, with the other either flexible or rigid. While in this transit! onary mode on the robot, the types of loads that the system could be exerting onto the colon may be examined. The loading location on the endoscope and overtube may be the same as in previous sections, however the types of motion and the rigidization situation are different, therefore these loads may be limited differently. For this situation, the loads can be grouped. Neither unit is moving along the insertion axis, so steering is no longer a concern and there are no insertion axis loads. While the robot isn’t steering the device, it can still be in a situation where the bending section is articulated. Thus, in reference to the force body diagram of FIG. 16 and the corresponding groups, in this case only groups la and lb are relevant, as the apparatus is not steering. la) Fbody2(not steering! Fbody5. Fbody6. FbodyA FbodylO. Ftipl. Ftip2

[0322] Looking at Fbody2(not steering), Fbody5, Fbody6, Fbody9, FbodylO, Ftipl, Ftip2, the scenario in which the robot might experience these loads is when the endoscope or overtube is moving along the insertion axis, or along its shaft. This is shown in FIG. 30. Because both devices are rigid in this state, they are not moving along this axis at all, so these loads will not change from what they were previously. Whichever algorithm was detecting these loads at the time they were moving will determine if any loads are too high.lb) Fbody 1, Fbody2 (steering), Fbody3, Fbody4, Fbody5, Fbody6, Fbody7, Fbody8

[0323] Looking at Fbody 1, Fbody2 (steering), Fbody3, Fbody4, Fbody5, Fbody6,Fbody7, and Fbody8, the scenario in which the robot might experience these loads in an ideal situation would be never since no devices are moving relative to the colon wall. However, the rigidization of the endoscope and overtube causes slight motion, or “ballooning” to occur when they rigidize. This is illustrated in FIG. 29._Being a lateral load, this may not be detectable by the robotic system. Therefore, the system may impose requirements on how much motion and how much load the devices create when transitioning from flexible to rigid. The act of rigidizing the overtube (which has a much more prominent ballooning effect, so is a conservative representation of both units) causes a higher load on the walls when the robot toggles between rigid and flexible while in a nominal diameter curve. These loads may be compared to a manual colonoscope device in the same test at multiple sections along the proximal body. It can be seen that not only is the nested system load on the walls smaller in most of these situations, but the load also actually decreases the more that the device is used (the bending stiffness decreases as it wears out over time).Methods for Transitioning from Flexible to Rigid

[0324] Putting all of this information together, a table can be created, and for each load it can describe what scenario may cause that load and what the mitigation or technique to maintain the load on the patient within or below a desired target range or threshold is for that scenario, as shown in Table 19.Table 19

[0325] By filling out the methods and / or techniques for each load to maintain the load on the patient within or below a desired target range or threshold, these methods and / or techniques can be applied to the motion situations matrix. The matched approach to each load on the device is shown in Table 20, below, to maintain the load on the patient within or below a desired target range or threshold:Table 20: matrix of techniquesThe Transitioning from Flexible to Rigid Mode Algorithm

[0326] For the unified algorithm when transitioning between flexible to rigid, the robot does not need to monitor loads. Optionally, the robot may monitor the endoscope and overtube forces and torques separately in this mode. The mitigation in this mode may again be the mechanical properties of the endoscope and overtube.Patient Load Thresholds

[0327] As discussed above, the methods and apparatuses described herein may be configured to compare the sensed force(s) and / or torque(s), e.g., the load on the patient, and may trigger one or more actions based on the magnitude of these sensed forces / loads in real (or near-real) time. For example, the sensed forces / loads may be compared to one or more thresholds or ranges. In some cases the sensed forces / loads may be compared to a firstthreshold to trigger an alert (which may vary based on the sensed forces / loads), to notify the user (via one or more of an audible, visual, and / or tactile alert or notification). This may be referred to as a notice threshold.

[0328] Any of these methods and apparatuses may also include a threshold to modify the behavior of the robot, particularly where the sensed forces / loads indicate high loads and / or torques during operation that may risk harm the patient. This may be referred to as an intervention threshold. To determine the thresholds at which the robot stops the user from continuing to navigate (e.g., an intervention threshold), a clear determination needed may be made of what is an unsafe load and when / what exactly a physician should be informed. Multiple tests were performed with a manual scope to determine possible ranges for these thresholds. In some cases nominal value of 20N was determined to be sufficient the first (e.g. notice) threshold. Thus, one or more thresholds may be between about ION, 12N, 15N, 17N, 18N, 19N, 20N, 21N, 22N, 23N, 24N, 25N, 30N, etc.

[0329] In some cases a threshold was identified for notifying the physician that they have reached a potential level of danger; this may be scaled to the level of sensed forces / loads. Any appropriate output may be used to convey the notice threshold, as mentioned. For example, FIG. 80 shows one example of a methods of visually displaying the notice. This display may be shown on a display screen, as shown in FIG. 81.

[0330] As mentioned, the output (notice) may be adjusted as the robot crosses each of the various force thresholds, in either a positive insertion direction or a negative withdrawal direction. For example if the sensed insertion / withdrawal force (and / or the load on the patient) is less than the lowest notice threshold (e g., <15N, less than 20N, etc.), the apparatus may provide an outlined indicator box reading “Low Force”. A colour indicator may be used (e.g., green). The system may operate as usual, without any notice / waming. If the sensed insertion / withdrawal force exceeds the first notice threshold, but is less than a second notice threshold (and / or the intervention threshold), e.g., between 15-25N, between 15-30N, between 20-3 ON, etc., the system may indicate in an outlined or shaded (e.g., in a colour such as yellow) indicator box, reading “Moderate Force” and the system may operate as usual, notifying the user to proceed with caution, but without any motion limits. In some cases, additional intermediate notice thresholds may be used. For example, if the insertion / withdrawal force is between 30-35 N, the system may indicate notice via an outlined or shaded indicator box (e.g., in orange, labelled “High Force” as illustrated in the non-limiting example of FIG. 81). Optionally, the apparatus or method may limit forward motion of both endoscope and overtube. In some cases, a warning message may pop-up with suggested actions, requiring the user to acknowledge the high load in order to continuemotion, e.g., on the touchscreen, before allowing continued forward or backwards motion (movement opposite the load direction is still allowed to relieve the load). Above a higher notice threshold (e.g., >3 IN, >32N, > 33N, >34N, >35N, >36N, >37N, >38N, >39N, >40N, etc.), the system may direct user to attempt reduction and may continue to limit movement and / or rigidity of the apparatus. For example, the apparatus may change an indicator box to red and may label it “Very high force”. Finally, if the insertion / withdrawal force is above the intervention threshold (e.g., >40 N), the apparatus may indicate a major fault and may stop movement of the endoscope / overtube and may de-rigidize the endoscope and / or overtube.

[0331] Similar torque thresholds may be used, including one or more torque notice thresholds and / or torque intervention thresholds. For example, the robot’s reactions to passing each of the torque notice thresholds (relevant in either the positive insertion direction or the negative direction) may include: if sensed torque is less than a first torque notice threshold (e.g., about < 300 Nmm, <400 Nmm, <500 Nmm, <550 Nmm, <600 Nmm, <650 Nmm, < 700Nmm, etc. of roll torque), the system may operate as usual, without any warning(s) or notice presented. If the sensed roll torque is within the range of the first notice threshold (e.g., between about 400-600 Nmm, between about 500-600 Nmm, etc.), the system may deliver a notice (e.g., may display a warning message pop-up) with suggested actions, and the motion is not limited. In some cases, if the sensed roll torque is within the range of a second notice threshold range (e.g., between about 500 Nmm-750 Nmm, between about 550 Nmm-650 Nmm, between about 600 Nmm - 700 Nmm of roll torque), the system may deliver a notice, such as a warning message pop-up with suggested actions; the use may be required to acknowledge the high torque load in order to continue motion, e.g., by contacting a touchscreen before allowing continued rolling motion. Optionally the system may reverse the direction of roll allowed. The system may direct the user to attempt action to reduce load. In some cases, if the sensed roll torque is within the range of a third notice threshold range (e.g., greater than about 650 Nmm of roll torque, greater than about 700 Nmm of roll torque, greater than about 750 Nmm of roll torque, etc.) but less than the intervention torque threshold, the system may deliver further notice, such as an additional warning message popup with suggested actions, in which the user is forced to acknowledge the high load in order to continue motion on the touchscreen before allowing continued rolling motion (and / or reverse direction roll allowed if desired). The system may direct the user to attempt action to reduce load. Finally, above the intervention torque threshold (e.g., greater than about 700 Nmm, greater than about 725 Nmm, greater than about 750 Nmm, greater than about 775 Nmm, greater than about 800 Nmm, etc.) the system may indicate / provide notice of a major fault, and may stop all motion and de-rigidize.

[0332] Thus, any of the patient load monitoring sub-systems described herein may include one or more alerts and / or indicators. Alternatively or additionally, any of these apparatuses may include or be configured to include an alert or indicator when the apparatus determines that a sufficiently high force is being applied that may lead to a kinematic change in the first or second (e.g., inner or outer) members. These apparatuses may be configured to emit one or more of a sound (e.g., tone, buzz, alarm, etc.) light (e g., LED), display, and / or tactile output. The tactile output may include vibration.

[0333] The apparatus and method may also be configured to perform a reduction or reversing direction opposite the high load, to ensure that a reversed direction would relieve the patient load in the desired way. For example, FIG. 82 is a graph showing the loads read during a manual intubation during using the robot. The load significantly reduces on the patient immediately after the 800 second mark 8201 and stays low after that point until the physician navigates into another difficult area. FIGS. 83 A and 83B show a graphs of loads read during a robotic intubation. The plot in FIG. 83A shows the position of the endoscope and overtube tips relative to the start of the navigation and FIG. 83B shows the loads in the X, Y, and Z directions on the sensors. The loads are significantly reduced on the patient (the red line) right after the 1300 second mark, as the robot is pulling the endoscope and overtube tips back. It is again reduced later after the 2000 second mark when the system pulls the devices out. This is the same as with the manual colonoscope, where motion in the direction opposite the load will relieve it. This can be extrapolated to the torques on the patient as well.

[0334] In general, the robotic apparatuses described herein tend to exert much less force on the patient (e.g., significantly lower load), as compared with manual endoscopes. This was confirmed during a comparison of manual and robotic system and is summarized in the graph of FIG. 84. This study examined the loads applied during cecal intubation and withdrawal, e.g., time with forces above 15.5 N (a conservative notice threshold), time with forces above 20 N (a second notice threshold), maximum force, and maximum torque (insertion direction). The percentage of time when the applied forces were above 15.5 N and 20 N showed that these forces were approximately 10% and 5% of the time, respectively for the manual colonoscope. Whereas robotically, the 15.5 N and 20 N forces occurred 3% and 0.62% of the total time assessed, respectively (see FIG. 84). Robotic cases reached the 20 N force threshold 5 times less than a manual scope, supporting the idea that dynamically rigidizing of the devices reduces navigational loads on the colon, and thus the clinical acceptability of robotic performance.

[0335] As for the maximum forces exerted on the colon, the maximum force average was37.2 N for the manual scope and 21.1 N for the robotic, a difference of approximately 43%lower loads on the patient with the robotic intubation. Furthermore, the average retroflexing insertion loads when intubating with a manual colonoscope were compared to the insertion loads during robotic retroflexing seen in the intubation mode analysis, above, and it was found that the average with a manual colonoscope was 12.4 N, which is nominally higher than the robotic loads.

[0336] Typically, when a physician encounters a higher load, they don’t necessarily immediately stop motion but instead look for indicators to see whether or not a continued increase in load on the patient will cause harm. One key indicator is to see if the tip of the colonoscope is still making forward progress, which can be determined from the camera view. If they don’t see tissue moving, they can also look for blanching of the tissue in the camera view. They may also pull back sooner if they know that the patient has a particularly weak colon (such as if the patient is older), have lesions from previous surgeries, or have ailments such as diverticulosis. Rather than steadily increasing a load, a user may also push with several repeated insertions and retreats of the colonoscope, essentially “poking” around with the tip to try to continue forward motion with minimal load. In some cases the robotic system may perform or account for some or all of these patient-specific factors when navigating. In some cases, the method or apparatus may simplify this by leaving the decision to stop or continue forward movement to the user (e.g., physician),

[0337] FIGS. 85A and 85B illustrate an example of graphs showing loads for a manual navigation (FIG. 85A) versus robotic navigation (FIG. 85B). The profiles of the loads are very different, with the manual navigation having many quick spikes in force and the robotic system having a steady increase in force throughout the run until the reduction. Additionally, in the manual intubation, the loads are initially limited to roughly less than 20 N, but the physician resorts to higher and higher loads as the navigation gets more difficult. All loading on the patient in this example was considered reasonable and safe for the given situation, because the physician was able to use the context of the situation to decide that a higher load would not be harmful. The lighter colored loads in the Figure below indicate when abdominal pressure was required to help the physician push through to the cecum Abdominal pressure was necessary in every manual intubation by a physician in this model.

[0338] As described above, the methods and apparatuses described herein may include as part of the sensing architecture one or more force sensors with measurement tolerances and force disturbances that may lead to some number of inaccuracies. In order to ensure that these inaccuracies do not result in patient harm, these methods and apparatuses may be configured to limit inaccuracy that could cause excessive loads in this system.

[0339] For example, FIG. 86A shows an example of a patient force plot during a typical robotic navigational run. The measured loads in this example do not measure internal loads that cancel out, because they can only detect the net force on the patient and have no way of distinguishing the overtube from the endoscope forces. However, it can be assumed that the magnitude of the forces on the patient are not significantly different than the magnitude of the net forces of the endoscope and overtube for the purposes of this general analysis to estimate the true and false positive rates rather than obtaining an exact number. FIG. 86B shows an example of error bars representing the potential inaccuracies of the measurement on the plot of FIG. 86A. So, if the line is the true patient force and the red dot is what is measured by the system, which could be any value between the error bars, it is possible to be measuring a load just below 15N or just below 18.5N when the true load is about 17N, as shown in this example. If the threshold for a harmful force is at 17N and the robot is measuring 18.5N at this time, then the robot would assume that the load on the patient is higher than what it actually is, which means that it would stop the system from continuing and / or warn the physician sooner than if it the measurement were perfectly accurate. However, on the other extreme, if the robot was measuring 14.5N when the true load is 17N, the system would not catch that the true load on the patient is too high and would not adequately stop the system or warn the physician in time. The threshold can be shifted to be more conservative in order to accommodate for the known error band. So, in this example, the threshold can be lowered to 14.5N to react to the load so that the robot is never in the situation where it potentially misses the 17N load. This would mean that when the true value on the patient is 17N, in one extreme the robot would be measuring 14.5N, but the system would react because the new threshold value is 14.5N. The tradeoff with this method is that the system may indicate that it exceeded the limit by 4N, and would react sooner than was necessary, resulting in a false positive. Thus, the apparatus may be configured to use the best accuracy spec for the sensors based on the lowest threshold. This may be based on an acceptable number of false positives, for example, by counting how many times both the robot and the manual intubation of the same colon model crossed a particular threshold. The manner in which lowering the threshold changes how many more positives the robot triggers when the threshold is lower may then be determined. This may be done for several threshold values to get a range of how the threshold value relates to the false positive count. For example, by looking at the total number of positives counted as the threshold is increased by increments of IN, as shown in FIG. 87A. The same data can be examined to see how many of these are false positives that have only occurred because the threshold was artificially lowered. This is shown in FIG. 87B The number of acceptable false positives can be obtained by comparing it to the manual data (forwhich the teams has both manual and robot data from the same physician using the same model). The physician would expect to have the same number of high loads as they would if they were intubating with a manual colonoscope. Comparing the positives from the manual colonoscopes to the robotic, as shown in FIG. 87C, shows that as the measurement approaches a threshold lowered by 7N on the x-axis, the horizontal lines indicating the number of positives in the manual run start to overlap with the robot run lines. So, to have the same or fewer positives that the physician experiences for the same model, lower the threshold by around ~7N. Too much higher and they would be seeing more positives than they would expect.

[0340] The same analysis can be performed with the torque data, suggesting that a threshold of ~300Nmm may useful. These values can be used to create boundaries for the sensing architecture. The approximate values can be divided into categories representing different areas in the robotic system. The first category may include sensing accuracy when the robot is detecting load without an overtube or endoscope present. This may include inaccuracies such as friction in the linear bearings, nonlinearities of the force sensing measurement, or temperature offsets. The second category may cover disturbance forces due to loads created by the mounting of the endoscope and overtube onto the handles. These can include dragging of a covering / drape on the robot, the stiffness of tubing lines attached to the endoscope, or gravity loads on the nested system. Finally, the last category may include loads that are caused by the friction and interaction forces between the endoscope and overtube. These are real forces that are actually being exerted on each of the two devices, but they are not loads that are seen by the patient.Integrated Force Sensing

[0341] Combining the resulting force / torque (e.g., patient load) sensing analysis described above results in a simple model in which the apparatus may sense, preferably from the proximal end (e g. “handle” region), insertion forces and / or torque for each of the first member (e.g., overtube) and second member (e g., endoscope) and may use these forces in combination with the rigidity status of each of the overtube and endoscope to determine the patient load during operation of the apparatus.

[0342] FIG. 88A schematically illustrates an example of this technique, which may be implemented as part of any of these apparatuses, similar to FIG. 15. This technique allows any load that would be felt by a physician manually intubating a colon to be detected by the apparatus. Thus, the output patient load may provide safety methods that will keep the patient from experiencing high loads in every normal use motion situation for the robot.

[0343] FIG. 88B shows another example of a chart summarizing a technique for estimating patient insertion force / load as described herein. As shown in both FIG. 88A and 88B, if the first elongate rigidizing member (e.g., overtube) is rigid and the second elongate rigidizing member (e.g., rigidizing endoscope) is rigid, and the insertion force for the second elongate rigidizing member is the same sign as the insertion force for the first elongate rigidizing member, then the force acting on the body is the higher of the first elongate rigidizing member insertion force and the second elongate rigidizing member insertion force, otherwise the force is net insertion force of the first and second elongate rigidizing members. As mentioned above, in any of these methods and apparatuses the bending status, and in particular retroflexing status, of the nested elongate rigidizing members may be used to further refine these estimates. For example, as shown in FIG. 88B, a retroflexion indicator (“retroflex flag”) may indicate if the second rigidizing elongate member and / or the first rigidizing elongate member is or is not retroflexing. As shown in this example, if the overtube is rigid and the endoscope is rigid and the endoscope insertion force / load is the same sign as the overtube insertion force, and the endoscope is not retroflexing (or when the endoscope is flexible / not rigid), then the force / load acting on the body is the higher of the overtube insertion force / load and the endoscope insertion force, otherwise the force is the net force / load of the overtube insertion force and the endoscope insertion force / load.Applications

[0344] Although many of the examples described herein are specific to colonoscopy and apparatuses and method for use in the colon, the methods and apparatuses described herein may include as part of an apparatus (e.g., system) for use in any appropriate region of the body, including the gastrointestinal (GI) tract (e.g., the upper GI or lower GI, including the esophagus, stomach, small intestine, large intestine, colon, etc.), the cardiovascular system (e.g., including pulmonary arteries, heart, neurovasculature, etc.), the reproductive tract (e.g., fallopian tubes, uterus, cervix, vagina, etc.), urogenital tract (e.g., urethra, urinary bladder, etc.), etc. In some of these applications endoscopes may be used. In other applications, catheters are more typically used, and these inventions would equally apply to robotically- actuated catheter-based systems.

[0345] For example, FIG. 89 schematically illustrates one example of an apparatus as described herein configured to perform a colonoscopy This apparatus includes an inner and outer pair of nested rigidizing members 8901 and a drive system 8905 (such as any of the dispensing / deploying drive sub-systems shown in FIGS. 2A-2D, 3, 4A-4B, 5, 6, 7A-7B, 8A- 8B, 9A-9B, 10A-10B, 11A-11B, 12, 13 and 14), which includes a patient load monitor 8905 (e.g., patient load monitor sub-system) that receives the sensor inputs described above anddetermines a load on the user and / or torque on the user. The patient load monitor may be integrated into the drive system, or it may be separate from the drive system.

[0346] FIG. 90 shows one example of an apparatus configured for use in a patient’s vasculature (e.g., the cardiovascular system), e.g., as part of a clot removal and / or interventional system. In FIG. 90 the apparatus includes an inner and an outer pair of nested rigi dizing members 9001 and a drive system 9005 (such as any of the dispensing / deploying drive sub-systems shown above), which includes a patient load monitor 9005 (e.g., patient load monitor sub-system) that receives the sensor inputs described above and determines a load on the user and / or torque on the user. As mentioned, the patient load monitor may be integrated into the drive system, or it may be separate from the drive system.

[0347] FIG. 91 schematically illustrates one example of an apparatus configured for use in a patient’s neurovasculature. In this example, the apparatus is shown including an inner and outer pair of nested rigi dizing members 9101 and a drive system 9105, which includes a patient load monitor 9005 that receives the sensor inputs described above and determines a load on the user and / or torque on the user.

[0348] Although the apparatuses described herein typically describe drive sub-systems in which the nested outer and inner members are primarily linear drivers (e.g., link assemblies) as described above, any appropriate dispensing / drive sub-system may be used, including, but not limited to, rotary dispensing / drive sub-systems. For example the apparatus may include a rotary dispensing sub-system in which the inner and / or outer nested members may be dispensed by rotating a mount to which the inner and / or outer members are attached. For example, any of the methods and apparatuses described herein may be used with a drive sub- system / dispensing sub-system such as those shown in PCT application WO2023205655A2, titled “Managing and manipulating a long length robotic endoscope,” and herein incorporated by reference in its entirety.

[0349] In general, the apparatuses described herein are configured to detect a force (load and / or torque) measured using one or more proximal sensors, as described above. Alternatively or additionally, one or more distal sensors may be used. For example, a distal sensor may include a force sensor that is integrated on the proximal end of the inner and / or outer members to detect contact force between the inner and / or outer member and a body region. In some examples the sensor may include a pressure sensor.

[0350] All publications and patent applications mentioned in this specification are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. Furthermore, it should be appreciated that all combinations of the foregoingconcepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein and may be used to achieve the benefits described herein.

[0351] Any of the methods (including user interfaces) described herein may be implemented as software, hardware or firmware, and may be described as a non-transitory computer-readable storage medium storing a set of instructions capable of being executed by a processor (e.g., computer, tablet, smartphone, etc.), that when executed by the processor causes the processor to control perform any of the steps, including but not limited to: displaying, communicating with the user, analyzing, modifying parameters (including timing, frequency, intensity, etc.), determining, alerting, or the like. For example, any of the methods described herein may be performed, at least in part, by an apparatus including one or more processors having a memory storing a non-transitory computer-readable storage medium storing a set of instructions for the processes(s) of the method.

[0352] While various embodiments have been described and / or illustrated herein in the context of fully functional computing systems, one or more of these example embodiments may be distributed as a program product in a variety of forms, regardless of the particular type of computer-readable media used to actually carry out the distribution. The embodiments disclosed herein may also be implemented using software modules that perform certain tasks. These software modules may include script, batch, or other executable files that may be stored on a computer-readable storage medium or in a computing system. In some embodiments, these software modules may configure a computing system to perform one or more of the example embodiments disclosed herein.

[0353] As described herein, the computing devices and systems described and / or illustrated herein broadly represent any type or form of computing device or system capable of executing computer-readable instructions, such as those contained within the modules described herein. In their most basic configuration, these computing device(s) may each comprise at least one memory device and at least one physical processor.

[0354] The term “memory” or “memory device,” as used herein, generally represents any type or form of volatile or non-volatile storage device or medium capable of storing data and / or computer-readable instructions. In one example, a memory device may store, load, and / or maintain one or more of the modules described herein. Examples of memory devices comprise, without limitation, Random Access Memory (RAM), Read Only Memory (ROM), flash memory, Hard Disk Drives (HDDs), Solid-State Drives (SSDs), optical disk drives, caches, variations or combinations of one or more of the same, or any other suitable storage memory.

[0355] In addition, the term “processor” or “physical processor,” as used herein, generally refers to any type or form of hardware-implemented processing unit capable of interpreting and / or executing computer-readable instructions. In one example, a physical processor may access and / or modify one or more modules stored in the above-described memory device. Examples of physical processors comprise, without limitation, microprocessors, microcontrollers, Central Processing Units (CPUs), Field-Programmable Gate Arrays (FPGAs) that implement softcore processors, Application-Specific Integrated Circuits (ASICs), portions of one or more of the same, variations or combinations of one or more of the same, or any other suitable physical processor.

[0356] Although illustrated as separate elements, the method steps described and / or illustrated herein may represent portions of a single application. In addition, in some embodiments one or more of these steps may represent or correspond to one or more software applications or programs that, when executed by a computing device, may cause the computing device to perform one or more tasks, such as the method step.

[0357] In addition, one or more of the devices described herein may transform data, physical devices, and / or representations of physical devices from one form to another. Additionally or alternatively, one or more of the modules recited herein may transform a processor, volatile memory, non-volatile memory, and / or any other portion of a physical computing device from one form of computing device to another form of computing device by executing on the computing device, storing data on the computing device, and / or otherwise interacting with the computing device.

[0358] The term “computer-readable medium,” as used herein, generally refers to any form of device, carrier, or medium capable of storing or carrying computer-readable instructions. Examples of computer-readable media comprise, without limitation, transmission-type media, such as carrier waves, and non-transitory-type media, such as magnetic-storage media (e.g., hard disk drives, tape drives, and floppy disks), optical -storage media (e.g., Compact Disks (CDs), Digital Video Disks (DVDs), and BLU-RAY disks), electronic-storage media (e.g., solid-state drives and flash media), and other distribution systems.

[0359] A person of ordinary skill in the art will recognize that any process or method disclosed herein can be modified in many ways. The process parameters and sequence of the steps described and / or illustrated herein are given by way of example only and can be varied as desired. For example, while the steps illustrated and / or described herein may be shown or discussed in a particular order, these steps do not necessarily need to be performed in the order illustrated or discussed.

[0360] The various exemplary methods described and / or illustrated herein may also omit one or more of the steps described or illustrated herein or comprise additional steps in addition to those disclosed. Further, a step of any method as disclosed herein can be combined with any one or more steps of any other method as disclosed herein.

[0361] The processor as described herein can be configured to perform one or more steps of any method disclosed herein. Alternatively or in combination, the processor can be configured to combine one or more steps of one or more methods as disclosed herein.

[0362] When a feature or element is herein referred to as being "on" another feature or element, it can be directly on the other feature or element or intervening features and / or elements may also be present. In contrast, when a feature or element is referred to as being "directly on" another feature or element, there are no intervening features or elements present. It will also be understood that, when a feature or element is referred to as being "connected", "attached" or "coupled" to another feature or element, it can be directly connected, attached or coupled to the other feature or element or intervening features or elements may be present. In contrast, when a feature or element is referred to as being "directly connected", "directly attached" or "directly coupled" to another feature or element, there are no intervening features or elements present. Although described or shown with respect to one embodiment, the features and elements so described or shown can apply to other embodiments. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed "adjacent" another feature may have portions that overlap or underlie the adjacent feature.

[0363] Terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. For example, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items and may be abbreviated as " / ".

[0364] Spatially relative terms, such as "under", "below", "lower", "over", "upper" and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is inverted, elements described as "under”, or "beneath"other elements or features would then be oriented "over" the other elements or features. Thus, the exemplary term "under" can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms "upwardly", "downwardly", "vertical", "horizontal" and the like are used herein for the purpose of explanation only unless specifically indicated otherwise.

[0365] Although the terms “first” and “second” may be used herein to describe various features / elements (including steps), these features / elements should not be limited by these terms, unless the context indicates otherwise. These terms may be used to distinguish one feature / element from another feature / element. Thus, a first feature / element discussed below could be termed a second feature / element, and similarly, a second feature / element discussed below could be termed a first feature / element without departing from the teachings of the present invention.

[0366] In general, any of the apparatuses and methods described herein should be understood to be inclusive, but all or a sub-set of the components and / or steps may alternatively be exclusive and may be expressed as “consisting of’ or alternatively “consisting essentially of’ the various components, steps, sub-components or sub-steps.

[0367] As used herein in the specification and claims, including as used in the examples and unless otherwise expressly specified, all numbers may be read as if prefaced by the word "about" or “approximately,” even if the term does not expressly appear. The phrase “about” or “approximately” may be used when describing magnitude and / or position to indicate that the value and / or position described is within a reasonable expected range of values and / or positions. For example, a numeric value may have a value that is + / - 0.1% of the stated value (or range of values), + / - 1% of the stated value (or range of values), + / - 2% of the stated value (or range of values), + / - 5% of the stated value (or range of values), + / - 10% of the stated value (or range of values), etc. Any numerical values given herein should also be understood to include about or approximately that value, unless the context indicates otherwise. For example, if the value "10" is disclosed, then "about 10" is also disclosed. Any numerical range recited herein is intended to include all sub-ranges subsumed therein. It is also understood that when a value is disclosed that "less than or equal to" the value, "greater than or equal to the value" and possible ranges between values are also disclosed, as appropriately understood by the skilled artisan. For example, if the value "X" is disclosed the "less than or equal to X" as well as "greater than or equal to X" (e.g., where X is a numerical value) is also disclosed. It is also understood that the throughout the application, data is provided in a number of different formats, and that this data, represents endpoints and starting points, andranges for any combination of the data points. For example, if a particular data point “10” and a particular data point “15” are disclosed, it is understood that greater than, greater than or equal to, less than, less than or equal to, and equal to 10 and 15 are considered disclosed as well as between 10 and 15. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0368] Although various illustrative embodiments are described above, any of a number of changes may be made to various embodiments without departing from the scope of the invention as described by the claims. Optional features of various device and system embodiments may be included in some embodiments and not in others. Therefore, the foregoing description is provided primarily for exemplary purposes and should not be interpreted to limit the scope of the invention as it is set forth in the claims.

[0369] The examples and illustrations included herein show, by way of illustration and not of limitation, specific embodiments in which the subject matter may be practiced. As mentioned, other embodiments may be utilized and derived there from, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. Such embodiments of the inventive subject matter may be referred to herein individually or collectively by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept, if more than one is, in fact, disclosed. Thus, although specific embodiments have been illustrated and described herein, any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description.

Claims

CLAIMSWhat is claimed is:

1. An apparatus, the apparatus comprising: a first mount configured to couple to a first rigidizing elongate member; a second mount configured to couple to a second rigidizing elongate member that is nested with the first rigidizing elongate member; a drive configured to linearly drive the second mount relative to the first mount; a first sensor coupled to the first mount and configured to sense a force and / or load from the first rigidizing elongate member; a second sensor coupled to the second mount and configured to sense a force and / or load from the second rigidizing elongate member; and a controller comprising one or more processors receiving input from the first sensor and the second sensor, wherein the controller is configured to determine a force and / or load on the patient based on: the force and / or load sensed by the first sensor, the force and / or load sensed by the second sensor, a net force and / or load from both the first and second rigidizing elongate members, and a rigidization state of the first rigidizing elongate member and / or the second rigidizing elongate member, wherein the controller is configured to provide an output based on the determine load on the patient.

2. The apparatus of claim 1, wherein the controller is configured to determine the force and / or load on the patient by setting the force and / or load on the patient to a larger of the force and / or load from the first sensor and the force and / or load from the second sensor if both the first and second rigidizing elongate members are in a rigid configuration and if a sign of the force and / or load from the first sensor is the same as a sign of the force and / or load from the second sensor, otherwise setting the force and / or load on the patient to the net force and / or load from both the first and second rigidizing elongate members.

3. The apparatus of claim 1, wherein the controller is configured to determine the force and / or load on the patient further based on a retroflexion indicator indicating if the second rigidizing elongate member is or is not retroflexing.

4. The apparatus of claim 3, wherein the controller is configured to determine the force and / or load on the patient by setting the force and / or load on the patient to a larger ofthe force and / or load from the first sensor and the force and / or load from the second sensor if both the first and second rigi dizing elongate members are in a rigid configuration and if a sign of the force and / or load from the first sensor is the same as a sign of the force and / or load from the second sensor and if the retroflexion indicator indicates that the second rigidizing elongate member is not retroflexing, otherwise setting the force and / or load on the patient to the net force and / or load from both the first and second rigidizing elongate members.

5. The apparatus of claim 1, further comprising a plurality of telescoping links wherein the first mount and the second mount are each coupled to an outer link of the plurality of telescoping links.

6. The apparatus of claim 5, wherein the first sensor is coupled between the first mount and to the outer link.

7. The apparatus of claim 5, wherein the second sensor is coupled between the second mount and the outer link.

8. The apparatus of claim 1, wherein the first mount is configured to couple to an overtube.

9. The apparatus of claim 1, wherein the second mount is configured to couple to a shield and an endoscope or to the endoscope.

10. The apparatus of claim 1, wherein the second mount comprises one or more actuators for actuating one or more tendons to steer the second rigidizing elongate member.

11. The apparatus of claim 1, further comprising a net sensor configured to sense the net force and / or load from the first and second rigidizing elongate members.

12. The apparatus of claim 11, wherein the net sensor comprises a local net sensor coupled at a first end to both the first mount and the second mount, and at an opposite end to an outer link to which both the first and second mounts are attached.

13. The apparatus of claim 1, wherein the first or second sensor comprises a net sensor configured to sense the net force and / or load from the first and second rigidizing elongate members.

14. The apparatus of claim 1, further comprising one or more pressures sensors configured to determine a pressure applied to the first and / or second rigidizing elongate member.

15. The apparatus of claim 1, wherein the controller is configured to determine the rigidization state of the first and / or second member based on a positive or negative fluid pressure applied to the first and / or second member to rigidize the first and / or second members.

16. The apparatus of claim 1, wherein the output comprises an alert.

17. The apparatus of claim 1, wherein the output comprises a series of alerts based on the magnitude of the determined force and / or load.

18. The apparatus of claim 1, wherein the output comprises a change in the rigidity of the first and / or second rigidizing elongate members.

19. A method, the method comprising: receiving or determining an insertion force and / or load for a first rigidizing member of a nested robotic apparatus; receiving or determining an insertion force and / or load for a second rigidizing member of the nested robotic apparatus; receiving or determining a rigidization status of the first rigidizing member; receiving or determining a rigidization status of the second rigidizing member; determining a force and / or load on a patient for the nested robotic apparatus based on at least: the insertion force and / or load for the first rigidizing member, the insertion force and / or load for the second rigidizing member, a net insertion force and / or load for the first and second rigidizing members, the rigidization status of the first rigidizing member and the rigidization status of the second rigidizing member; and providing an output based on the determined force and / or load on the patient.

20. The method of claim 19, wherein determining the force and / or load on the patient comprises setting the force and / or load on the patient to a larger of the force and / or load for the first rigidizing member and the force and / or load for a second rigidizing member if both the first and second rigidizing members are in a rigid configuration and if a sign of the force and / or load for the first rigidizing member is the same as a- 107 -sign of the force and / or load for a second rigidizing member, otherwise setting the force and / or load on the patient to the net insertion force and / or load from both the first and second elongate members.

21. The method of claim 19, wherein determining a force and / or load on a patient for the nested robotic apparatus further comprises determining the force and / or load on the patient further based on a retroflexion indicator indicating if the second rigidizing elongate member is or is not retroflexing.

22. The method of claim 21, wherein determining the force and / or load on the patient comprises setting the force and / or load on the patient to a larger of the force and / or load for the first rigidizing member and the force and / or load for a second rigidizing member if both the first and second rigidizing members are in a rigid configuration and if a sign of the force and / or load for the first rigidizing member is the same as a sign of the force and / or load for a second rigidizing member and if the retroflexion indicator indicates that the second rigidizing elongate member is not retroflexing, otherwise setting the force and / or load on the patient to the net insertion force and / or load from both the first and second elongate members.

23. The method of claim 19, wherein receiving or determining the insertion force and / or load for the first rigidizing member comprises receiving the insertion force and / or load for an overtube of the nested robotic apparatus.

24. The method of claim 19, wherein receiving or determining the insertion force and / or load for the first rigidizing member comprises receiving the insertion force and / or load from a first force and / or load sensor coupled between a first mount to which the first rigidizing member is coupled and a link assembly.

25. The method of claim 19, wherein receiving or determining the insertion force and / or load for the second rigidizing member comprises receiving the insertion force and / or load for an endoscope of the nested robotic apparatus.

26. The method of claim 19, wherein receiving or determining the insertion force and / or load for the second rigidizing member comprises receiving the insertion force and / or load from a second force and / or load sensor coupled between a second mount to which the second rigidizing member is coupled and a link assembly.- 108 -27. The method of claim 19, wherein receiving or determining the rigidization status of the first rigidizing member comprises determining the rigidization status based on a pressure applied to rigidize the first rigidizing member.

28. The method of claim 27, wherein the pressure applied is a positive and / or negative pressure.

29. The method of claim 19, wherein receiving or determining a rigidization status of the second rigidizing member comprises determining the rigidization status based on a pressure applied to rigidize the second rigidizing member.

30. The method of claim 19, wherein determining comprises determining in real time.

31. The method of claim 19, wherein providing the output comprises emitting an alert.

32. The method of claim 19, wherein providing the output comprises emitting a series of alerts based on the magnitude of the determined force and / or load.

33. The method of claim 19, wherein providing the output comprises de-rigi dizing the first and / or second rigidizing member.

34. An apparatus, the apparatus comprising: a plurality of telescoping links; a first mount coupled to an outer link of the plurality of telescoping links, wherein the first mount is configured to couple to a first elongate rigidizing member; a second mount coupled to the outer link, wherein the second mount is configured to couple to a second elongate rigidizing member that is nested with the first elongate rigidizing member and to linearly actuate relative to the outer link; a first force and / or load sensor coupled to the first mount and configured to sense a force and / or load from the first elongate rigidizing member; a second force and / or load sensor coupled to the second mount and configured to sense a force and / or load from the second elongate rigidizing member; and a controller comprising one or more processors receiving input from the first force and / or load sensor and the second force and / or load sensor, wherein the controller is configured to determine a force and / or load on the patient based on: the force and / or load sensed by the first force and / or load sensor, the force and / or load sensed by the second force and / or load sensor, a net force and / or load from both the first and second elongate rigidizing member, and a- 109 -rigidization state of the first and / or second elongate rigidizing member, and to provide an output based on the determined force and / or load on the patient.

35. An apparatus, the apparatus comprising: a plurality of telescoping links; a first mount coupled to an outer link of the telescoping links, wherein the first mount is configured to couple to a first elongate member; a second mount coupled to the outer link of the telescoping links, wherein the second mount is configured to linearly actuate and to couple to a second elongate member that is nested with the first elongate member; a first force and / or load sensor coupled between the first mount and the outer link and configured to sense a force and / or load from the first elongate member; a second force and / or load sensor coupled between the second mount and the outer link and configured to sense a force and / or load from the second elongate member; a net force and / or load sensor configured to sense a load from both the first and second elongate members; and a controller comprising one or more processors receiving input from the first force and / or load sensor and the second force and / or load sensor, wherein the controller is configured to determine a force and / or load on the patient based on the force and / or load sensed by the first force and / or load sensor, the force and / or load sensed by the second force and / or load sensor, a net force and / or load from both the first and second elongate members, and a rigidization state of the first and / or second member and to provide an output based on the determine force and / or load on the patient.

36. A method, the method comprising: receiving or determining an insertion force and / or load for a first member of a nested robotic apparatus; receiving or determining an insertion force and / or load for a second member of a nested robotic apparatus; receiving or determining a rigidization status of the first member; receiving or determining a rigidization status of the second member; determining a force and / or load on the patient for the nested robotic apparatus from the insertion force and / or load for the first member, the insertion force and / or load force and / or load for the second member, a net insertion force - 110 -and / or load for the first and second members, the rigidization status of the first member and the rigidization status of the second member; and providing an output based on the determined force and / or load on the patient.

37. A method, the method comprising: receiving or determining an insertion force and / or load for a first member of a nested robotic apparatus; receiving or determining an insertion force and / or load for a second member of a nested robotic apparatus, receiving or determining a rigidization status of the first member; receiving or determining a rigidization status of the second member; determining, in real time, a patient force and / or load for the nested robotic apparatus from the insertion force and / or load for the first member, the insertion force and / or load for eh second member, a net insertion force and / or load for the first and second members, the rigidization status of the first member and the rigidization status of the second member, by setting the force and / or load on the patient to the higher of the insertion force and / or load for the first member or the insertion force and / or load for the second member when both the first member and the second member in a rigid configuration and setting the force and / or load on the patient as the net insertion force and / or load when the first elongate member is in a flexible configuration and either the second elongate member is in a flexible configuration or the insertion force and / or load of the second elongate member has a different sign than a sign of the insertion force and / or load of the first elongate member; and providing an output based on the determine force and / or load on the patient.

38. An apparatus comprising: a link assembly; a first force and / or load sensor coupled to a first mount on an outer link of the link assembly and configured to sense an insertion force and / or load from a first elongate member of a nested robotic apparatus that is coupled to the first mount; a second force and / or load sensor coupled to a second mount on the outer link and configured to sense an insertion force and / or load from a second elongate member of the nested robotic apparatus that is coupled to the second mount; one or more processors; and- Ill -a controller comprises one or more processors and a memory coupled to the one or more processors, the memory storing computer-program instructions, that, when executed by the one or more processors, perform a computer- implemented method comprising: determining a force and / or load on the patient for the nested robotic apparatus from the insertion force and / or load for the first member, the insertion force and / or load for the second member, a net insertion force and / or load for the first and second members, a rigidization status of the first member and a rigidization status of the second member; and providing an output based on the determined force and / or load on the patient.- 112 -

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