Patent Description:
<CIT> relates to a method of controlling advancement of a shapeable medical device within an anatomic path. The method comprises identifying a reference shape of one or more portions of the shapeable medical device, advancing the shapeable medical device along the anatomic path, obtaining a plurality of localization data to determine a real shape of at least the one or more portions of the shapeable instrument when advanced along the anatomic path, and monitoring advancement of the shapeable medical device by determining a differential between the real shape and the reference shape of the one or more portions.

The systems and methods disclosed herein are directed to medical instruments, and more particularly to systems and methods that compensate for compression of elongated shafts of the medical instruments.

Medical procedures may involve accessing and visualizing an internal region of a patient for diagnostic or therapeutic purposes. Endoscopy, for example, may include accessing and visualizing the inside of a patient's lumen (e.g., airways). As another example, laparoscopy may include accessing and visualizing an internal cavity of a patient. During a procedure, a medical instrument such as, for example, a scope, may be inserted into the patient's body and an instrument can be passed through the scope to a tissue site identified for diagnosis and/or treatment.

In some instances, the medical instrument can include an elongated shaft (or an elongated body generally) that is steerable or articulable so as to navigate an interior region of the patient. In some instances, the medical instrument can be robotically controlled.

The systems, techniques and devices of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

In some instances, medical instruments include elongated shafts configured for insertion into a body of a patient. The elongated shafts can be articulable so that they can be navigated within the patient. The elongated shafts can include pull wires that are actuable to articulate the elongated shafts. Pull wire-based movements (i.e., movements caused by actuating the pull wires) may cause undesirable compression (e.g., axial compression) of the elongated shafts. The systems and methods of the present disclosure can compensate for this compression by determining the amount of the compression and moving (e.g., advancing) the medical instrument with an instrument positioning device (e.g., a robotic arm) to compensate for the compression.

In some instances, a compression compensation parameter is used to determine the compression of the elongated shaft of the medical instrument. The compression compensation parameter can relate a characteristic of pull wire-based movement (e.g., pull wire tension, pull wire displacement, actuator displacement, commanded angle of articulation, measured angle of articulation, etc.) to axial compression. The compression compensation parameter can be determined during a calibration process of the medical instrument. The compression compensation parameter can be stored in a memory (e.g., non- transitory computer readable medium) on the medical instrument.

Methods of surgery described here below are not claimed but serve a better understanding of the invention.

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, such as laparoscopy, and non-invasive, such as endoscopy, procedures. Among endoscopy procedures, the system may be capable of performing bronchoscopy, ureteroscopy, gastroenterology, etc..

In addition to performing the breadth of procedures, the system may provide additional benefits, such as enhanced imaging and guidance to assist the physician. Additionally, the system may provide the physician with the ability to perform the procedure from an ergonomic position without the need for awkward arm motions and positions. Still further, the system may provide the physician with the ability to perform the procedure with improved ease of use such that one or more of the instruments of the system can be controlled by a single user.

Various embodiments will be described below in conjunction with the drawings for purposes of illustration. It should be appreciated that many other implementations of the disclosed concepts are possible, and various advantages can be achieved with the disclosed implementations. Headings are included herein for reference and to aid in locating various sections. These headings are not intended to limit the scope of the concepts described with respect thereto. Such concepts may have applicability throughout the entire specification.

The robotically-enabled medical system may be configured in a variety of ways depending on the particular procedure. <FIG> illustrates an embodiment of a cart-based robotically-enabled system <NUM> arranged for a diagnostic and/or therapeutic bronchoscopy procedure. During a bronchoscopy, the system <NUM> may comprise a cart <NUM> having one or more robotic arms <NUM> to deliver a medical instrument, such as a steerable endoscope <NUM>, which may be a procedure-specific bronchoscope for bronchoscopy, to a natural orifice access point (i.e., the mouth of the patient positioned on a table in the present example) to deliver diagnostic and/or therapeutic tools. As shown, the cart <NUM> may be positioned proximate to the patient's upper torso in order to provide access to the access point. Similarly, the robotic arms <NUM> may be actuated to position the bronchoscope relative to the access point. The arrangement in <FIG> may also be utilized when performing a gastro-intestinal (GI) procedure with a gastroscope, a specialized endoscope for GI procedures. <FIG> depicts an example embodiment of the cart in greater detail.

With continued reference to <FIG>, once the cart <NUM> is properly positioned, the robotic arms <NUM> may insert the steerable endoscope <NUM> into the patient robotically, manually, or a combination thereof. As shown, the steerable endoscope <NUM> may comprise at least two telescoping parts, such as an inner leader portion and an outer sheath portion, each portion coupled to a separate instrument driver from the set of instrument drivers <NUM>, each instrument driver coupled to the distal end of an individual robotic arm. This linear arrangement of the instrument drivers <NUM>, which facilitates coaxially aligning the leader portion with the sheath portion, creates a "virtual rail" <NUM> that may be repositioned in space by manipulating the one or more robotic arms <NUM> into different angles and/or positions. The virtual rails described herein are depicted in the Figures using dashed lines, and accordingly the dashed lines do not depict any physical structure of the system. Translation of the instrument drivers <NUM> along the virtual rail <NUM> telescopes the inner leader portion relative to the outer sheath portion or advances or retracts the endoscope <NUM> from the patient. The angle of the virtual rail <NUM> may be adjusted, translated, and pivoted based on clinical application or physician preference. For example, in bronchoscopy, the angle and position of the virtual rail <NUM> as shown represents a compromise between providing physician access to the endoscope <NUM> while minimizing friction that results from bending the endoscope <NUM> into the patient's mouth.

The endoscope <NUM> may be directed down the patient's trachea and lungs after insertion using precise commands from the robotic system until reaching the target destination or operative site. In order to enhance navigation through the patient's lung network and/or reach the desired target, the endoscope <NUM> may be manipulated to telescopically extend the inner leader portion from the outer sheath portion to obtain enhanced articulation and greater bend radius. The use of separate instrument drivers <NUM> also allows the leader portion and sheath portion to be driven independent of each other.

For example, the endoscope <NUM> may be directed to deliver a biopsy needle to a target, such as, for example, a lesion or nodule within the lungs of a patient. The needle may be deployed down a working channel that runs the length of the endoscope to obtain a tissue sample to be analyzed by a pathologist. Depending on the pathology results, additional tools may be deployed down the working channel of the endoscope for additional biopsies. After identifying a nodule to be malignant, the endoscope <NUM> may endoscopically deliver tools to resect the potentially cancerous tissue. In some instances, diagnostic and therapeutic treatments may need to be delivered in separate procedures. In those circumstances, the endoscope <NUM> may also be used to deliver a fiducial to "mark" the location of the target nodule as well. In other instances, diagnostic and therapeutic treatments may be delivered during the same procedure.

The system <NUM> may also include a movable tower <NUM>, which may be connected via support cables to the cart <NUM> to provide support for controls, electronics, fluidics, optics, sensors, and/or power to the cart <NUM>. Placing such functionality in the tower <NUM> allows for a smaller form factor cart <NUM> that may be more easily adjusted and/or repositioned by an operating physician and his/her staff. Additionally, the division of functionality between the cart / table and the support tower <NUM> reduces operating room clutter and facilitates improving clinical workflow. While the cart <NUM> may be positioned close to the patient, the tower <NUM> may be stowed in a remote location to stay out of the way during a procedure.

In support of the robotic systems described above, the tower <NUM> may include component(s) of a computer-based control system that stores computer program instructions, for example, within a non-transitory computer-readable storage medium such as a persistent magnetic storage drive, solid state drive, etc. The execution of those instructions, whether the execution occurs in the tower <NUM> or the cart <NUM>, may control the entire system or sub-system(s) thereof. For example, when executed by a processor of the computer system, the instructions may cause the components of the robotics system to actuate the relevant carriages and arm mounts, actuate the robotics arms, and control the medical instruments. For example, in response to receiving the control signal, the motors in the joints of the robotics arms may position the arms into a certain posture.

The tower <NUM> may also include a pump, flow meter, valve control, and/or fluid access in order to provide controlled irrigation and aspiration capabilities to system that may be deployed through the endoscope <NUM>. These components may also be controlled using the computer system of tower <NUM>. In some embodiments, irrigation and aspiration capabilities may be delivered directly to the endoscope <NUM> through separate cable(s).

The tower <NUM> may include a voltage and surge protector designed to provide filtered and protected electrical power to the cart <NUM>, thereby avoiding placement of a power transformer and other auxiliary power components in the cart <NUM>, resulting in a smaller, more moveable cart <NUM>.

The tower <NUM> may also include support equipment for the sensors deployed throughout the robotic system <NUM>. For example, the tower <NUM> may include opto-electronics equipment for detecting, receiving, and processing data received from the optical sensors or cameras throughout the robotic system <NUM>. In combination with the control system, such opto-electronics equipment may be used to generate real-time images for display in any number of consoles deployed throughout the system, including in the tower <NUM>. Similarly, the tower <NUM> may also include an electronic subsystem for receiving and processing signals received from deployed electromagnetic (EM) sensors. The tower <NUM> may also be used to house and position an EM field generator for detection by EM sensors in or on the medical instrument.

The tower <NUM> may also include a console <NUM> in addition to other consoles available in the rest of the system, e.g., console mounted on top of the cart. The console <NUM> may include a user interface and a display screen, such as a touchscreen, for the physician operator. Consoles in system <NUM> are generally designed to provide both robotic controls as well as pre-operative and real-time information of the procedure, such as navigational and localization information of the endoscope <NUM>. When the console <NUM> is not the only console available to the physician, it may be used by a second operator, such as a nurse, to monitor the health or vitals of the patient and the operation of system, as well as provide procedure-specific data, such as navigational and localization information.

The tower <NUM> may be coupled to the cart <NUM> and endoscope <NUM> through one or more cables or connections (not shown). In some embodiments, the support functionality from the tower <NUM> may be provided through a single cable to the cart <NUM>, simplifying and de-cluttering the operating room. In other embodiments, specific functionality may be coupled in separate cabling and connections. For example, while power may be provided through a single power cable to the cart, the support for controls, optics, fluidics, and/or navigation may be provided through a separate cable.

<FIG> provides a detailed illustration of an embodiment of the cart from the cart-based robotically-enabled system shown in <FIG>. The cart <NUM> generally includes an elongated support structure <NUM> (often referred to as a "column"), a cart base <NUM>, and a console <NUM> at the top of the column <NUM>. The column <NUM> may include one or more carriages, such as a carriage <NUM> (alternatively "arm support") for supporting the deployment of one or more robotic arms <NUM> (three shown in <FIG>). The carriage <NUM> may include individually configurable arm mounts that rotate along a perpendicular axis to adjust the base of the robotic arms <NUM> for better positioning relative to the patient. The carriage <NUM> also includes a carriage interface <NUM> that allows the carriage <NUM> to vertically translate along the column <NUM>.

The carriage interface <NUM> is connected to the column <NUM> through slots, such as slot <NUM>, that are positioned on opposite sides of the column <NUM> to guide the vertical translation of the carriage <NUM>. The slot <NUM> contains a vertical translation interface to position and hold the carriage at various vertical heights relative to the cart base <NUM>. Vertical translation of the carriage <NUM> allows the cart <NUM> to adjust the reach of the robotic arms <NUM> to meet a variety of table heights, patient sizes, and physician preferences. Similarly, the individually configurable arm mounts on the carriage <NUM> allow the robotic arm base <NUM> of robotic arms <NUM> to be angled in a variety of configurations.

In some embodiments, the slot <NUM> may be supplemented with slot covers that are flush and parallel to the slot surface to prevent dirt and fluid ingress into the internal chambers of the column <NUM> and the vertical translation interface as the carriage <NUM> vertically translates. The slot covers may be deployed through pairs of spring spools positioned near the vertical top and bottom of the slot <NUM>. The covers are coiled within the spools until deployed to extend and retract from their coiled state as the carriage <NUM> vertically translates up and down. The spring-loading of the spools provides force to retract the cover into a spool when carriage <NUM> translates towards the spool, while also maintaining a tight seal when the carriage <NUM> translates away from the spool. The covers may be connected to the carriage <NUM> using, for example, brackets in the carriage interface <NUM> to ensure proper extension and retraction of the cover as the carriage <NUM> translates.

The column <NUM> may internally comprise mechanisms, such as gears and motors, that are designed to use a vertically aligned lead screw to translate the carriage <NUM> in a mechanized fashion in response to control signals generated in response to user inputs, e.g., inputs from the console <NUM>.

The robotic arms <NUM> may generally comprise robotic arm bases <NUM> and end effectors <NUM>, separated by a series of linkages <NUM> that are connected by a series of joints <NUM>, each joint comprising an independent actuator, each actuator comprising an independently controllable motor. Each independently controllable joint represents an independent degree of freedom available to the robotic arm. Each of the arms <NUM> have seven joints, and thus provide seven degrees of freedom. A multitude of joints result in a multitude of degrees of freedom, allowing for "redundant" degrees of freedom. Redundant degrees of freedom allow the robotic arms <NUM> to position their respective end effectors <NUM> at a specific position, orientation, and trajectory in space using different linkage positions and joint angles. This allows for the system to position and direct a medical instrument from a desired point in space while allowing the physician to move the arm joints into a clinically advantageous position away from the patient to create greater access, while avoiding arm collisions.

The cart base <NUM> balances the weight of the column <NUM>, carriage <NUM>, and arms <NUM> over the floor. Accordingly, the cart base <NUM> houses heavier components, such as electronics, motors, power supply, as well as components that either enable movement and/or immobilize the cart. For example, the cart base <NUM> includes rollable wheel-shaped casters <NUM> that allow for the cart to easily move around the room prior to a procedure. After reaching the appropriate position, the casters <NUM> may be immobilized using wheel locks to hold the cart <NUM> in place during the procedure.

Positioned at the vertical end of column <NUM>, the console <NUM> allows for both a user interface for receiving user input and a display screen (or a dual-purpose device such as, for example, a touchscreen <NUM>) to provide the physician user with both pre-operative and intra-operative data. Potential pre-operative data on the touchscreen <NUM> may include pre-operative plans, navigation and mapping data derived from pre-operative computerized tomography (CT) scans, and/or notes from pre-operative patient interviews. Intra-operative data on display may include optical information provided from the tool, sensor and coordinate information from sensors, as well as vital patient statistics, such as respiration, heart rate, and/or pulse. The console <NUM> may be positioned and tilted to allow a physician to access the console from the side of the column <NUM> opposite carriage <NUM>. From this position the physician may view the console <NUM>, robotic arms <NUM>, and patient while operating the console <NUM> from behind the cart <NUM>. As shown, the console <NUM> also includes a handle <NUM> to assist with maneuvering and stabilizing cart <NUM>.

<FIG> illustrates an embodiment of a robotically-enabled system <NUM> arranged for ureteroscopy. In a ureteroscopic procedure, the cart <NUM> may be positioned to deliver a ureteroscope <NUM>, a procedure-specific endoscope designed to traverse a patient's urethra and ureter, to the lower abdominal area of the patient. In a ureteroscopy, it may be desirable for the ureteroscope <NUM> to be directly aligned with the patient's urethra to reduce friction and forces on the sensitive anatomy in the area. As shown, the cart <NUM> may be aligned at the foot of the table to allow the robotic arms <NUM> to position the ureteroscope <NUM> for direct linear access to the patient's urethra. From the foot of the table, the robotic arms <NUM> may insert ureteroscope <NUM> along the virtual rail <NUM> directly into the patient's lower abdomen through the urethra.

After insertion into the urethra, using similar control techniques as in bronchoscopy, the ureteroscope <NUM> may be navigated into the bladder, ureters, and/or kidneys for diagnostic and/or therapeutic applications. For example, the ureteroscope <NUM> may be directed into the ureter and kidneys to break up kidney stone build up using laser or ultrasonic lithotripsy device deployed down the working channel of the ureteroscope <NUM>. After lithotripsy is complete, the resulting stone fragments may be removed using baskets deployed down the ureteroscope <NUM>.

<FIG> illustrates an embodiment of a robotically-enabled system similarly arranged for a vascular procedure. In a vascular procedure, the system <NUM> may be configured such the cart <NUM> may deliver a medical instrument <NUM>, such as a steerable catheter, to an access point in the femoral artery in the patient's leg. The femoral artery presents both a larger diameter for navigation as well as relatively less circuitous and tortuous path to the patient's heart, which simplifies navigation. As in a ureteroscopic procedure, the cart <NUM> may be positioned towards the patient's legs and lower abdomen to allow the robotic arms <NUM> to provide a virtual rail <NUM> with direct linear access to the femoral artery access point in the patient's thigh / hip region. After insertion into the artery, the medical instrument <NUM> may be directed and inserted by translating the instrument drivers <NUM>. Alternatively, the cart may be positioned around the patient's upper abdomen in order to reach alternative vascular access points, such as, for example, the carotid and brachial arteries near the shoulder and wrist.

Embodiments of the robotically-enabled medical system may also incorporate the patient's table. Incorporation of the table reduces the amount of capital equipment within the operating room by removing the cart, which allows greater access to the patient. <FIG> illustrates an embodiment of such a robotically-enabled system arranged for a bronchoscopy procedure. System <NUM> includes a support structure or column <NUM> for supporting platform <NUM> (shown as a "table" or "bed") over the floor. Much like in the cart-based systems, the end effectors of the robotic arms <NUM> of the system <NUM> comprise instrument drivers <NUM> that are designed to manipulate an elongated medical instrument, such as a bronchoscope <NUM> in <FIG>, through or along a virtual rail <NUM> formed from the linear alignment of the instrument drivers <NUM>. In practice, a C-arm for providing fluoroscopic imaging may be positioned over the patient's upper abdominal area by placing the emitter and detector around table <NUM>.

<FIG> provides an alternative view of the system <NUM> without the patient and medical instrument for discussion purposes. As shown, the column <NUM> may include one or more carriages <NUM> shown as ring-shaped in the system <NUM>, from which the one or more robotic arms <NUM> may be based. The carriages <NUM> may translate along a vertical column interface <NUM> that runs the length of the column <NUM> to provide different vantage points from which the robotic arms <NUM> may be positioned to reach the patient. The carriage(s) <NUM> may rotate around the column <NUM> using a mechanical motor positioned within the column <NUM> to allow the robotic arms <NUM> to have access to multiples sides of the table <NUM>, such as, for example, both sides of the patient. In embodiments with multiple carriages, the carriages may be individually positioned on the column and may translate and/or rotate independent of the other carriages. While carriages <NUM> need not surround the column <NUM> or even be circular, the ring-shape as shown facilitates rotation of the carriages <NUM> around the column <NUM> while maintaining structural balance. Rotation and translation of the carriages <NUM> allows the system to align the medical instruments, such as endoscopes and laparoscopes, into different access points on the patient.

The arms <NUM> may be mounted on the carriages through a set of arm mounts <NUM> comprising a series of joints that may individually rotate and/or telescopically extend to provide additional configurability to the robotic arms <NUM>. Additionally, the arm mounts <NUM> may be positioned on the carriages <NUM> such that, when the carriages <NUM> are appropriately rotated, the arm mounts <NUM> may be positioned on either the same side of table <NUM> (as shown in <FIG>), on opposite sides of table <NUM> (as shown in <FIG>), or on adjacent sides of the table <NUM> (not shown).

The column <NUM> structurally provides support for the table <NUM>, and a path for vertical translation of the carriages. Internally, the column <NUM> may be equipped with lead screws for guiding vertical translation of the carriages, and motors to mechanize the translation of said carriages based the lead screws. The column <NUM> may also convey power and control signals to the carriage <NUM> and robotic arms <NUM> mounted thereon.

The table base <NUM> serves a similar function as the cart base <NUM> in cart <NUM> shown in <FIG>, housing heavier components to balance the table/bed <NUM>, the column <NUM>, the carriages <NUM>, and the robotic arms <NUM>. The table base <NUM> may also incorporate rigid casters to provide stability during procedures. Deployed from the bottom of the table base <NUM>, the casters may extend in opposite directions on both sides of the base <NUM> and retract when the system <NUM> needs to be moved.

Continuing with <FIG>, the system <NUM> may also include a tower (not shown) that divides the functionality of system <NUM> between table and tower to reduce the form factor and bulk of the table. As in earlier disclosed embodiments, the tower may be provide a variety of support functionalities to table, such as processing, computing, and control capabilities, power, fluidics, and/or optical and sensor processing. The tower may also be movable to be positioned away from the patient to improve physician access and de-clutter the operating room. Additionally, placing components in the tower allows for more storage space in the table base for potential stowage of the robotic arms. The tower may also include a console that provides both a user interface for user input, such as keyboard and/or pendant, as well as a display screen (or touchscreen) for pre-operative and intra-operative information, such as real-time imaging, navigation, and tracking information.

In some embodiments, a table base may stow and store the robotic arms when not in use. <FIG> illustrates a system <NUM> that stows robotic arms in an embodiment of the table-based system. In system <NUM>, carriages <NUM> may be vertically translated into base <NUM> to stow robotic arms <NUM>, arm mounts <NUM>, and the carriages <NUM> within the base <NUM>. Base covers <NUM> may be translated and retracted open to deploy the carriages <NUM>, arm mounts <NUM>, and arms <NUM> around column <NUM>, and closed to stow to protect them when not in use. The base covers <NUM> may be sealed with a membrane <NUM> along the edges of its opening to prevent dirt and fluid ingress when closed.

<FIG> illustrates an embodiment of a robotically-enabled table-based system configured for a ureteroscopy procedure. In a ureteroscopy, the table <NUM> may include a swivel portion <NUM> for positioning a patient off-angle from the column <NUM> and table base <NUM>. The swivel portion <NUM> may rotate or pivot around a pivot point (e.g., located below the patient's head) in order to position the bottom portion of the swivel portion <NUM> away from the column <NUM>. For example, the pivoting of the swivel portion <NUM> allows a C-arm (not shown) to be positioned over the patient's lower abdomen without competing for space with the column (not shown) below table <NUM>. By rotating the carriage <NUM> (not shown) around the column <NUM>, the robotic arms <NUM> may directly insert a ureteroscope <NUM> along a virtual rail <NUM> into the patient's groin area to reach the urethra. In a ureteroscopy, stirrups <NUM> may also be fixed to the swivel portion <NUM> of the table <NUM> to support the position of the patient's legs during the procedure and allow clear access to the patient's groin area.

In a laparoscopic procedure, through small incision(s) in the patient's abdominal wall, minimally invasive instruments (elongated in shape to accommodate the size of the one or more incisions) may be inserted into the patient's anatomy. After inflation of the patient's abdominal cavity, the instruments, often referred to as laparoscopes, may be directed to perform surgical tasks, such as grasping, cutting, ablating, suturing, etc. <FIG> illustrates an embodiment of a robotically-enabled table-based system configured for a laparoscopic procedure. As shown in <FIG>, the carriages <NUM> of the system <NUM> may be rotated and vertically adjusted to position pairs of the robotic arms <NUM> on opposite sides of the table <NUM>, such that laparoscopes <NUM> may be positioned using the arm mounts <NUM> to be passed through minimal incisions on both sides of the patient to reach his/her abdominal cavity.

To accommodate laparoscopic procedures, the robotically-enabled table system may also tilt the platform to a desired angle. <FIG> illustrates an embodiment of the robotically-enabled medical system with pitch or tilt adjustment. As shown in <FIG>, the system <NUM> may accommodate tilt of the table <NUM> to position one portion of the table at a greater distance from the floor than the other. Additionally, the arm mounts <NUM> may rotate to match the tilt such that the arms <NUM> maintain the same planar relationship with table <NUM>. To accommodate steeper angles, the column <NUM> may also include telescoping portions <NUM> that allow vertical extension of column <NUM> to keep the table <NUM> from touching the floor or colliding with base <NUM>.

<FIG> provides a detailed illustration of the interface between the table <NUM> and the column <NUM>. Pitch rotation mechanism <NUM> may be configured to alter the pitch angle of the table <NUM> relative to the column <NUM> in multiple degrees of freedom. The pitch rotation mechanism <NUM> may be enabled by the positioning of orthogonal axes <NUM>, <NUM> at the column-table interface, each axis actuated by a separate motor <NUM>, <NUM> responsive to an electrical pitch angle command. Rotation along one screw <NUM> would enable tilt adjustments in one axis <NUM>, while rotation along the other screw <NUM> would enable tilt adjustments along the other axis <NUM>.

For example, pitch adjustments are particularly useful when trying to position the table in a Trendelenburg position, i.e., position the patient's lower abdomen at a higher position from the floor than the patient's lower abdomen, for lower abdominal surgery. The Trendelenburg position causes the patient's internal organs to slide towards his/her upper abdomen through the force of gravity, clearing out the abdominal cavity for minimally invasive tools to enter and perform lower abdominal surgical procedures, such as laparoscopic prostatectomy.

The end effectors of the system's robotic arms comprise (i) an instrument driver (alternatively referred to as "instrument drive mechanism" or "instrument device manipulator") that incorporate electro-mechanical means for actuating the medical instrument and (ii) a removable or detachable medical instrument which may be devoid of any electro-mechanical components, such as motors. This dichotomy may be driven by the need to sterilize medical instruments used in medical procedures, and the inability to adequately sterilize expensive capital equipment due to their intricate mechanical assemblies and sensitive electronics. Accordingly, the medical instruments may be designed to be detached, removed, and interchanged from the instrument driver (and thus the system) for individual sterilization or disposal by the physician or the physician's staff. In contrast, the instrument drivers need not be changed or sterilized, and may be draped for protection.

<FIG> illustrates an example instrument driver. Positioned at the distal end of a robotic arm, instrument driver <NUM> comprises of one or more drive units <NUM> arranged with parallel axes to provide controlled torque to a medical instrument via drive shafts <NUM>. Each drive unit <NUM> comprises an individual drive shaft <NUM> for interacting with the instrument, a gear head <NUM> for converting the motor shaft rotation to a desired torque, a motor <NUM> for generating the drive torque, an encoder <NUM> to measure the speed of the motor shaft and provide feedback to the control circuitry, and control circuity <NUM> for receiving control signals and actuating the drive unit. Each drive unit <NUM> being independent controlled and motorized, the instrument driver <NUM> may provide multiple (four as shown in <FIG>) independent drive outputs to the medical instrument. In operation, the control circuitry <NUM> would receive a control signal, transmit a motor signal to the motor <NUM>, compare the resulting motor speed as measured by the encoder <NUM> with the desired speed, and modulate the motor signal to generate the desired torque.

For procedures that require a sterile environment, the robotic system may incorporate a drive interface, such as a sterile adapter connected to a sterile drape, that sits between the instrument driver and the medical instrument. The chief purpose of the sterile adapter is to transfer angular motion from the drive shafts of the instrument driver to the drive inputs of the instrument while maintaining physical separation, and thus sterility, between the drive shafts and drive inputs. Accordingly, an example sterile adapter may comprise of a series of rotational inputs and outputs intended to be mated with the drive shafts of the instrument driver and drive inputs on the instrument. Connected to the sterile adapter, the sterile drape, comprised of a thin, flexible material such as transparent or translucent plastic, is designed to cover the capital equipment, such as the instrument driver, robotic arm, and cart (in a cart-based system) or table (in a table-based system). Use of the drape would allow the capital equipment to be positioned proximate to the patient while still being located in an area not requiring sterilization (i.e., non-sterile field). On the other side of the sterile drape, the medical instrument may interface with the patient in an area requiring sterilization (i.e., sterile field).

<FIG> illustrates an example medical instrument with a paired instrument driver. Like other instruments designed for use with a robotic system, medical instrument <NUM> comprises an elongated shaft <NUM> (or elongate body) and an instrument base <NUM>. The instrument base <NUM>, also referred to as an "instrument handle" due to its intended design for manual interaction by the physician, may generally comprise rotatable drive inputs <NUM>, e.g., receptacles, pulleys or spools, that are designed to be mated with drive outputs <NUM> that extend through a drive interface on instrument driver <NUM> at the distal end of robotic arm <NUM>. When physically connected, latched, and/or coupled, the mated drive inputs <NUM> of instrument base <NUM> may share axes of rotation with the drive outputs <NUM> in the instrument driver <NUM> to allow the transfer of torque from drive outputs <NUM> to drive inputs <NUM>. In some embodiments, the drive outputs <NUM> may comprise splines that are designed to mate with receptacles on the drive inputs <NUM>.

The elongated shaft <NUM> is designed to be delivered through either an anatomical opening or lumen, e.g., as in endoscopy, or a minimally invasive incision, e.g., as in laparoscopy. The elongated shaft <NUM> may be either flexible (e.g., having properties similar to an endoscope) or rigid (e.g., having properties similar to a laparoscope) or contain a customized combination of both flexible and rigid portions. When designed for laparoscopy, the distal end of a rigid elongated shaft may be connected to an end effector comprising a jointed wrist formed from a clevis with an axis of rotation and a surgical tool, such as, for example, a grasper or scissors, that may be actuated based on force from the tendons as the drive inputs rotate in response to torque received from the drive outputs <NUM> of the instrument driver <NUM>. When designed for endoscopy, the distal end of a flexible elongated shaft may include a steerable or controllable bending section that may be articulated and bent based on torque received from the drive outputs <NUM> of the instrument driver <NUM>.

Torque from the instrument driver <NUM> is transmitted down the elongated shaft <NUM> using tendons within the shaft <NUM>. These individual tendons, such as pull wires, may be individually anchored to individual drive inputs <NUM> within the instrument handle <NUM>. From the handle <NUM>, the tendons are directed down one or more pull lumens within the elongated shaft <NUM> and anchored at the distal portion of the elongated shaft <NUM>. In laparoscopy, these tendons may be coupled to a distally mounted end effector, such as a wrist, grasper, or scissor. Under such an arrangement, torque exerted on drive inputs <NUM> would transfer tension to the tendon, thereby causing the end effector to actuate in some way. In laparoscopy, the tendon may cause a joint to rotate about an axis, thereby causing the end effector to move in one direction or another. Alternatively, the tendon may be connected to one or more jaws of a grasper at distal end of the elongated shaft <NUM>, where tension from the tendon cause the grasper to close.

In endoscopy, the tendons may be coupled to a bending or articulating section positioned along the elongated shaft <NUM> (e.g., at the distal end) via adhesive, control ring, or other mechanical fixation. When fixedly attached to the distal end of a bending section, torque exerted on drive inputs <NUM> would be transmitted down the tendons, causing the softer, bending section (sometimes referred to as the articulable section or region) to bend or articulate. Along the non-bending sections, it may be advantageous to spiral or helix the individual pull lumens that direct the individual tendons along (or inside) the walls of the endoscope shaft to balance the radial forces that result from tension in the pull wires. The angle of the spiraling and/or spacing there between may be altered or engineered for specific purposes, wherein tighter spiraling exhibits lesser shaft compression under load forces, while lower amounts of spiraling results in greater shaft compression under load forces, but also exhibits limits bending. On the other end of the spectrum, the pull lumens may be directed parallel to the longitudinal axis of the elongated shaft <NUM> to allow for controlled articulation in the desired bending or articulable sections.

In endoscopy, the elongated shaft <NUM> houses a number of components to assist with the robotic procedure. The shaft may comprise of a working channel for deploying surgical tools, irrigation, and/or aspiration to the operative region at the distal end of the shaft <NUM>. The shaft <NUM> may also accommodate wires and/or optical fibers to transfer signals to/from an optical assembly at the distal tip, which may include of an optical camera. The shaft <NUM> may also accommodate optical fibers to carry light from proximally-located light sources, such as light emitting diodes, to the distal end of the shaft.

At the distal end of the instrument <NUM>, the distal tip may also comprise the opening of a working channel for delivering tools for diagnostic and/or therapy, irrigation, and aspiration to an operative site. The distal tip may also include a port for a camera, such as a fiberscope or a digital camera, to capture images of an internal anatomical space. Relatedly, the distal tip may also include ports for light sources for illuminating the anatomical space when using the camera.

In the example of <FIG>, the drive shaft axes, and thus the drive input axes, are orthogonal to the axis of the elongated shaft. This arrangement, however, complicates roll capabilities for the elongated shaft <NUM>. Rolling the elongated shaft <NUM> along its axis while keeping the drive inputs <NUM> static results in undesirable tangling of the tendons as they extend off the drive inputs <NUM> and enter pull lumens within the elongate shaft <NUM>. The resulting entanglement of such tendons may disrupt any control algorithms intended to predict movement of the flexible elongate shaft during an endoscopic procedure.

<FIG> illustrates an alternative design for an instrument driver and instrument where the axes of the drive units are parallel to the axis of the elongated shaft of the instrument. As shown, a circular instrument driver <NUM> comprises four drive units with their drive outputs <NUM> aligned in parallel at the end of a robotic arm <NUM>. The drive units, and their respective drive outputs <NUM>, are housed in a rotational assembly <NUM> of the instrument driver <NUM> that is driven by one of the drive units within the assembly <NUM>. In response to torque provided by the rotational drive unit, the rotational assembly <NUM> rotates along a circular bearing that connects the rotational assembly <NUM> to the non-rotational portion <NUM> of the instrument driver. Power and controls signals may be communicated from the non-rotational portion <NUM> of the instrument driver <NUM> to the rotational assembly <NUM> through electrical contacts may be maintained through rotation by a brushed slip ring connection (not shown). In other embodiments, the rotational assembly <NUM> may be responsive to a separate drive unit that is integrated into the non-rotatable portion <NUM>, and thus not in parallel to the other drive units. The rotational mechanism <NUM> allows the instrument driver <NUM> to rotate the drive units, and their respective drive outputs <NUM>, as a single unit around an instrument driver axis <NUM>.

Like earlier disclosed embodiments, an instrument <NUM> may comprise of an elongated shaft portion <NUM> and an instrument base <NUM> (shown with a transparent external skin for discussion purposes) comprising a plurality of drive inputs <NUM> (such as receptacles, pulleys, and spools) that are configured to receive the drive outputs <NUM> in the instrument driver <NUM>. Unlike prior disclosed embodiments, instrument shaft <NUM> extends from the center of instrument base <NUM> with an axis substantially parallel to the axes of the drive inputs <NUM>, rather than orthogonal as in the design of <FIG>.

When coupled to the rotational assembly <NUM> of the instrument driver <NUM>, the medical instrument <NUM>, comprising instrument base <NUM> and instrument shaft <NUM>, rotates in combination with the rotational assembly <NUM> about the instrument driver axis <NUM>. Since the instrument shaft <NUM> is positioned at the center of instrument base <NUM>, the instrument shaft <NUM> is coaxial with instrument driver axis <NUM> when attached. Thus, rotation of the rotational assembly <NUM> causes the instrument shaft <NUM> to rotate about its own longitudinal axis. Moreover, as the instrument base <NUM> rotates with the instrument shaft <NUM>, any tendons connected to the drive inputs <NUM> in the instrument base <NUM> are not tangled during rotation. Accordingly, the parallelism of the axes of the drive outputs <NUM>, drive inputs <NUM>, and instrument shaft <NUM> allows for the shaft rotation without tangling any control tendons.

Traditional endoscopy may involve the use of fluoroscopy (e.g., as may be delivered through a C-arm) and other forms of radiation-based imaging modalities to provide endoluminal guidance to an operator physician. In contrast, the robotic systems contemplated by this disclosure can provide for non-radiation-based navigational and localization means to reduce physician exposure to radiation and reduce the amount of equipment within the operating room. As used herein, the term "localization" may refer to determining and/or monitoring the position of objects in a reference coordinate system. Technologies such as pre-operative mapping, computer vision, real-time EM tracking, and robot command data may be used individually or in combination to achieve a radiation-free operating environment. In other cases, where radiation-based imaging modalities are still used, the pre-operative mapping, computer vision, real-time EM tracking, and robot command data may be used individually or in combination to improve upon the information obtained solely through radiation-based imaging modalities.

<FIG> is a block diagram illustrating a localization system <NUM> that estimates a location of one or more elements of the robotic system, such as the location of the instrument, in accordance to an example embodiment. The localization system <NUM> may be a set of one or more computer devices configured to execute one or more instructions. The computer devices may be embodied by a processor (or processors) and computer-readable memory in one or more components discussed above. By way of example and not limitation, the computer devices may be in the tower <NUM> shown in <FIG>, the cart shown in <FIG>, the beds shown in <FIG>, etc..

As shown in <FIG>, the localization system <NUM> may include a localization module <NUM> that processes input data <NUM>-<NUM> to generate location data <NUM> for the distal tip of a medical instrument. The location data <NUM> may be data or logic that represents a location and/or orientation of the distal end of the instrument relative to a frame of reference. The frame of reference can be a frame of reference relative to the anatomy of the patient or to a known object, such as an EM field generator (see discussion below for the EM field generator).

The various input data <NUM>-<NUM> are now described in greater detail. Pre-operative mapping may be accomplished through the use of the collection of low dose CT scans. Pre-operative CT scans generate two-dimensional images, each representing a "slice" of a cutaway view of the patient's internal anatomy. When analyzed in the aggregate, image-based models for anatomical cavities, spaces and structures of the patient's anatomy, such as a patient lung network, may be generated. Techniques such as center-line geometry may be determined and approximated from the CT images to develop a three-dimensional volume of the patient's anatomy, referred to as preoperative model data <NUM>. The use of center-line geometry is discussed in <CIT>. Network topological models may also be derived from the CT-images, and are particularly appropriate for bronchoscopy.

In some embodiments, the instrument may be equipped with a camera to provide vision data <NUM>. The localization module <NUM> may process the vision data to enable one or more vision-based location tracking. For example, the preoperative model data may be used in conjunction with the vision data <NUM> to enable computer vision-based tracking of the medical instrument (e.g., an endoscope or an instrument advance through a working channel of the endoscope). For example, using the preoperative model data <NUM>, the robotic system may generate a library of expected endoscopic images from the model based on the expected path of travel of the endoscope, each image linked to a location within the model. Intra-operatively, this library may be referenced by the robotic system in order to compare real-time images captured at the camera (e.g., a camera at a distal end of the endoscope) to those in the image library to assist localization.

Other computer vision-based tracking techniques use feature tracking to determine motion of the camera, and thus the endoscope. Some feature of the localization module <NUM> may identify circular geometries in the preoperative model data <NUM> that correspond to anatomical lumens and track the change of those geometries to determine which anatomical lumen was selected, as well as the relative rotational and/or translational motion of the camera. Use of a topological map may further enhance vision-based algorithms or techniques.

Optical flow, another computer vision-based technique, may analyze the displacement and translation of image pixels in a video sequence in the vision data <NUM> to infer camera movement. Through the comparison of multiple frames over multiple iterations, movement and location of the camera (and thus the endoscope) may be determined.

The localization module <NUM> may use real-time EM tracking to generate a real-time location of the endoscope in a global coordinate system that may be registered to the patient's anatomy, represented by the preoperative model. In EM tracking, an EM sensor (or tracker) comprising of one or more sensor coils embedded in one or more locations and orientations in a medical instrument (e.g., an endoscopic tool) measures the variation in the EM field created by one or more static EM field generators positioned at a known location. The location information detected by the EM sensors is stored as EM data <NUM>. The EM field generator (or transmitter), may be placed close to the patient to create a low intensity magnetic field that the embedded sensor may detect. The magnetic field induces small currents in the sensor coils of the EM sensor, which may be analyzed to determine the distance and angle between the EM sensor and the EM field generator. These distances and orientations may be intra-operatively "registered" to the patient anatomy (e.g., the preoperative model) in order to determine the geometric transformation that aligns a single location in the coordinate system with a position in the pre-operative model of the patient's anatomy. Once registered, an embedded EM tracker in one or more positions of the medical instrument (e.g., the distal tip of an endoscope) may provide real-time indications of the progression of the medical instrument through the patient's anatomy.

Robotic command and kinematics data <NUM> may also be used by the localization module <NUM> to provide localization data <NUM> for the robotic system. Device pitch and yaw resulting from articulation commands may be determined during pre-operative calibration. Intra-operatively, these calibration measurements may be used in combination with known insertion depth information to estimate the position of the instrument. Alternatively, these calculations may be analyzed in combination with EM, vision, and/or topological modeling to estimate the position of the medical instrument within the network.

As <FIG> shows, a number of other input data can be used by the localization module <NUM>. For example, although not shown in <FIG>, an instrument utilizing shape-sensing fiber can provide shape data that the localization module <NUM> can use to determine the location and shape of the instrument.

The localization module <NUM> may use the input data <NUM>-<NUM> in combination(s). In some cases, such a combination may use a probabilistic approach where the localization module <NUM> assigns a confidence weight to the location determined from each of the input data <NUM>-<NUM>. Thus, where the EM data may not be reliable (as may be the case where there is EM interference) the confidence of the location determined by the EM data <NUM> can be decrease and the localization module <NUM> may rely more heavily on the vision data <NUM> and/or the robotic command and kinematics data <NUM>.

As discussed above, the robotic systems discussed herein may be designed to incorporate a combination of one or more of the technologies above. The robotic system's computer-based control system, based in the tower, bed and/or cart, may store computer program instructions, for example, within a non-transitory computer-readable storage medium such as a persistent magnetic storage drive, solid state drive, or the like, that, upon execution, cause the system to receive and analyze sensor data and user commands, generate control signals throughout the system, and display the navigational and localization data, such as the position of the instrument within the global coordinate system, anatomical map, etc..

Embodiments of the disclosure relate to systems and techniques for compensating for compression of medical instruments. Medical instruments can include elongated shafts that experience compression when articulated. As described herein, the medical instruments can be attached to instrument positioning devices that are configured to move the medical instruments to compensate for this compression. For example, an instrument positioning device can advance a medical instrument to compensate for compression in an elongated shaft of the medical instrument. In some embodiments, the amount of compression is determined using one or more compression compensation parameters. The one or more compression compensation parameters can be determined during calibration of the medical instrument.

<FIG> illustrates an embodiment of an elongated shaft <NUM> of a medical instrument <NUM>. The elongated shaft <NUM> is configured for insertion, in use, into a body of a patient. In some embodiments, the elongated shaft <NUM> is configured for insertion, for example, via a laparoscopic procedure, into a cavity of the patient. In some embodiments, the elongated shaft <NUM> is configured for insertion, for example, via an endoscopic procedure, into a lumen (or luminal network) of the patient. As shown in the embodiment of <FIG>, the medical instrument <NUM> may also include an instrument base <NUM> (or handle) that is configured to couple the medical instrument <NUM> to an instrument driver <NUM> of an instrument positioning device <NUM>, such as a robotic arm.

The elongated shaft <NUM> may be articulable (or steerable). That is, an operator may control the pose, shape, and/or articulation of the elongated shaft <NUM>. This may allow the operator to guide or navigate the elongated shaft <NUM> within the patient's body. In some embodiments, the medical instrument <NUM> is robotically controllable as described above. A remote operator may provide control signals or inputs to an instrument positioning device that manipulates (e.g., steers, articulates, inserts, etc.) the elongated shaft <NUM>. The elongated shaft <NUM> may be formed from a flexible or bendable material. In the illustrated embodiment, the elongated shaft <NUM> extends between a distal portion <NUM> and a proximal portion <NUM>. The distal portion <NUM> may include a distal tip. The distal portion <NUM> may be the leading end of the elongated shaft <NUM> (i.e., the end that is inserted, in use, into the patient). The proximal end <NUM> may connect (either removably or permanently) to the instrument base <NUM> (see <FIG>).

The medical instrument <NUM> can include pull wires (or tendons) that extend through one or more sections of the elongated shaft <NUM>. As described above, the pull wires are actuable to control the pose, shape, and/or articulation of the elongated shaft <NUM>. In the illustrated embodiment, two pull wires <NUM>, <NUM> extend through the elongated shaft <NUM>. Although the two pull wires <NUM>, <NUM> are illustrated, the medical instrument <NUM> may include other numbers of pull wires. For example, the medical instrument <NUM> can include one, two, three, four, five, six, or more pull wires. In the illustrated embodiment, the pull wires <NUM>, <NUM> extend through (i.e., within) the elongated shaft <NUM>. In another example, the pull wires <NUM>, <NUM> may extend along an exterior of the elongated shaft <NUM>. Further, although the pull wires <NUM>, <NUM> are illustrated extending straight (i.e., along a linear path) through the elongated shaft <NUM>, in other embodiments, the pull wires <NUM>, <NUM> may include one or more spiraled, coiled, or helical sections.

In one example, the pull wires <NUM>, <NUM> may be coupled to the distal end <NUM> of the elongated shaft <NUM>. In another example (not shown), the pull wires <NUM>, <NUM> may be coupled to position located proximally relative to the distal end <NUM> of the elongated shaft <NUM>. At the proximal end <NUM>, the pull wires <NUM>, <NUM> can extend into the instrument base <NUM> (see <FIG>). Within the instrument base <NUM>, the pull wires <NUM>, <NUM> can be coupled to drive inputs (such as drive inputs <NUM> described above) that are configured actuate (i.e., tension or pull) the pull wires <NUM>, <NUM>. In some embodiments, each pull wire <NUM>, <NUM> is coupled to an independently operable drive input. When the medical instrument <NUM> is coupled to the instrument driver <NUM> of the instrument positioning device <NUM>, the drive inputs engage with corresponding drive outputs on the instrument positioning device <NUM> as described above. The drive outputs can actuate the drive inputs so as to robotically control actuation of the pull wires <NUM>, <NUM>.

As discussed throughout this disclosure, the elongated shaft <NUM> may experience compression as it is articulated or moved to various positions, poses, or shapes. The compression may be axial compression (i.e., compression measured along a longitudinal axis of the elongated shaft <NUM>). The compression may be caused by pull wire-based movements. In other words, actuation (i.e., pulling or tensioning) the pull wires <NUM>, <NUM> to control articulation, pose, and/or shape of the elongated shaft <NUM> may cause compression of the elongated shaft <NUM>.

In some instances, compression of the elongated shaft <NUM> may be undesirable. For example, an operator may command an articulation (e.g., bending) of the elongated shaft <NUM>. In addition to the commanded articulation, however, the elongated shaft <NUM> may also experience compression, resulting in an unexpected or undesired position of the distal end <NUM> of the elongated shaft <NUM>. This may cause difficulties for the operator while driving (e.g., guiding or controlling) the medical instrument <NUM>. This may also cause inaccuracy in a robotic navigation system used to drive and/or monitor the position of the medical instrument <NUM>. For example, the robotic navigation system can use telemetry data from the instrument positioning device(s) <NUM> to determine or estimate a position (for example, the position of a distal tip or portion) of the medical instrument <NUM> within the body. Compression of the elongated body, if unaccounted for, can cause the robotic navigation system to may not accurately determine or estimate the position of the medical instrument <NUM>. For example, if compression is not accounted for, the robotic navigation system may determine or estimate that the distal tip is more inserted into the body than it actually is.

In <FIG>, the elongated shaft <NUM> is illustrated in a default or uncompressed state. In the default state, the elongated shaft <NUM> has a length L measured between the distal end <NUM> and the proximal end <NUM>. As will be discussed below, compression of the elongated shaft <NUM> may result in a decreasing the length L.

For ease of illustration and clarity, various other features of the medical instrument <NUM> are omitted in <FIG>. For example, the medical instrument <NUM> may also include a working channel, imaging device(s) (e.g., one or more cameras), spatial sensor(s) (e.g., position sensors, orientations sensors), etc..

<FIG> depicts the elongated shaft <NUM> of the medical instrument <NUM> experiencing axial compression caused by an example of pull wire-based movement. In the illustrated example, a force F has been applied to the pull wire <NUM> in the illustrated direction. As illustrated, the force F causes a tension or displacement of the pull wire <NUM> that causes the elongated shaft <NUM> to articulate or bend to an angle α, as shown. This type of pull-wire based movement may be used by an operator to steer or turn the medical instrument <NUM>. In addition to the articulation of the elongated shaft <NUM> to the angle α, the tension or displacement of the pull wire <NUM> also causes an axial compression of the elongated shaft <NUM>. In the illustrated embodiment, the distal portion <NUM> of the elongated shaft <NUM> has axially compressed or retracted a distance C, as shown. That is, the length L of the elongated shaft <NUM> is reduced by the distance C in response to the pull wire-based movement (i.e., articulation to the angle α) of the elongated shaft <NUM>. As mentioned above, this may result in the distal portion <NUM> of the elongated shaft <NUM> being out of position. This axial compression may be undesirable.

<FIG> depicts the elongated shaft <NUM> of the medical instrument <NUM> experiencing axial compression caused by another example of pull-wire based movement. In this example, both pull wires <NUM>, <NUM> are actuated equally by the force F. Because both pull wires <NUM>, <NUM> are actuated equally, the elongated shaft <NUM> experiences compression without bending. In the illustrated example, the length L of the elongated shaft <NUM> is axially compressed by a distance C as shown. This type of pull-wire based movement may be used by an operator to increase the stiffness or sensitivity of the elongated shaft <NUM>. In some instances, however, the operator may desire to increase the stiffness or sensitivity of the elongated shaft <NUM> without changing the position of the distal portion <NUM> of the elongated shaft <NUM>, and thus, the axial compression illustrated in <FIG> may be undesirable.

As described in further detail below, according to the present disclosure, axial compressions caused by pull-wire based movements (as illustrated, for example, in <FIG>) can be compensated for, allowing for increased movement accuracy and an improved driving experience of medical instruments <NUM> including elongated shafts <NUM>.

Compression of the elongated shaft <NUM> of the medical instrument <NUM> may be compensated for by moving (e.g., advancing or retracting) the medical instrument <NUM> with the instrument positioning device <NUM> (e.g., a robotic arm) to which it is coupled. For example, the extent or amount (e.g., length) of compression (e.g., along a longitudinal axis) can be calculated, determined, or estimated, and the instrument positioning device <NUM> can advance the medical instrument <NUM> a corresponding amount such that the distal portion <NUM> of the elongated shaft <NUM> remains in the expected position. In other words, the instrument positioning device <NUM> can advance the medical instrument <NUM> an amount corresponding to the amount of compression such that the distal portion <NUM> is located in a position that corresponds to the position of the distal portion <NUM> in the absence of the axial compression.

<FIG> illustrates the medical instrument <NUM> coupled to an embodiment of an instrument positioning device <NUM>. As shown, the medical instrument <NUM> includes the elongated shaft <NUM> extending between a distal portion <NUM> and a proximal portion <NUM>. The proximal portion <NUM> is coupled (either removably or permanently) to the instrument base <NUM>. The instrument base <NUM> is coupled to the instrument driver <NUM> of the instrument positioning device <NUM>. In <FIG>, only a portion of the instrument positioning device <NUM> is shown. The instrument positioning device <NUM> may comprise a robotic arm, such as any of the robotic arms <NUM>, <NUM>, <NUM> shown in <FIG> described above. As mentioned above, the instrument driver <NUM> can include drive outputs for actuating the drive inputs in the instrument base <NUM> to actuate the pull wires <NUM>, <NUM>. The instrument positioning device <NUM> is movable to insert (or advance) or retract the elongated shaft <NUM> of the medical instrument device <NUM> within the patient.

<FIG> depicts an example of the instrument positioning device <NUM> configured to move to compensate for axial compression caused by pull wire-based movement of the medical instrument <NUM>. In <FIG>, the elongated shaft <NUM> is illustrated undergoing pull wire-based movement as shown and described in <FIG>, which causes a compression C of the elongated shaft <NUM>. As shown in the example of <FIG>, the instrument position device <NUM> can move a distance D in the direction illustrated (i.e., advancing the elongated shaft <NUM>) to compensate for the compression C. In the illustrated example, the distance D is equal to the distance of the compression C, such that the position of the distal portion <NUM> is advanced to the position it would have been in absent the compression. As shown, the elongated shaft <NUM> is articulated to the angle α and advanced the distance D to compensate for the compression C.

<FIG> depicts an example of the instrument positioning device <NUM> configured to move to compensate for axial compression caused by another type of pull wire-based movement of the medical instrument <NUM>. In <FIG>, the elongated shaft <NUM> is illustrated undergoing pull wire-based movement as shown and described in <FIG>, which causes a compression C of the elongated shaft <NUM>. As shown in the example of <FIG>, the instrument position device <NUM> can move a distance D in the direction illustrated (i.e., advancing the elongated shaft <NUM>) to compensate for the compression C. In the illustrated example, the distance D is equal to the distance of the compression C, such that the position of the distal portion <NUM> is advanced to the position it would have been in absent the compression.

<FIG> is a flow chart illustrating an example method <NUM> for compensating for compression in a medical instrument <NUM>. The method <NUM> begins at block <NUM> at which a commanded pull-wire based movement of the medical instrument <NUM> is received. The commanded pull wire-based movement may be received from an operator. The operator may provide the commanded pull-wire based movement using a remotely located input device. The commanded pull wire-based movement can be executed by the instrument positioning device <NUM>.

Next, the method <NUM> moves to block <NUM> at which the compression of the medical instrument <NUM> caused by the commanded pull wire-based movement is determined. In one example, determining the compression comprises measuring the compression. In another example, determining the compression comprises calculating the compression. In another example, determining the compression comprises estimating the compression.

As will be discussed in further detail below, the compression may be determined, calculated, or estimated using one or more compression compensation parameters. The compression compensation parameter and its use are discussed in further detail below in section II.

In conjunction with using one or more compression compensation parameters, the compression of the medical instrument <NUM> can be determined, calculated, or estimated based on data from one or more other techniques. In one example, fluoroscopic images of the medical instrument <NUM> can be analyzed to determine compression, in addition to the use of the compression compensation parameters. In another example, the medical instrument <NUM> can include one or more spatial sensors (e.g., EM sensors) positioned thereon. The spatial sensors may provide position data regarding the position of the medical instrument <NUM>. This position data can be analyzed to determine the compression of the medical instrument <NUM>, in addition to the use of the compression compensation parameters. In another example, the medical instrument <NUM> can include a shape-sensing fiber. The shape-sensing fiber can provide data about the shape or pose of the medical instrument <NUM>. This data can be analyzed to determine the compression of the medical instrument <NUM>, in addition to the use of the compression compensation parameters. In another example, the compression of the medical instrument <NUM> is determined using a model, e.g., based on the shape, size, and material properties of the elongated shaft of the medical instrument <NUM>, in addition to the use of the compression compensation parameters. In one example of determining compression of the medical instrument <NUM> using a model, the elongated shaft <NUM> of the medical instrument <NUM> can be divided into one or more sections that can be modeled using Euler-Bernoulli beam theory.

In another example, the compression of a first medical instrument can be measured relative to a second medical instrument. , in addition to the use of the compression compensation parameters. As described below in section II. D, two or more medical instruments can be configured for telescoping use. That is, a second medical instrument can telescope within a working channel of the first medical instrument. The first medical instrument can include a spatial sensor located at its distal portion. The second medical instrument can include a spatial sensor located at its distal portion. The compression can be determined or estimated by comparing the relative position of these two position sensors. This may ensure or increase the likelihood that the distal portions of the two medical instruments remain aligned (i.e., flush).

At block <NUM> of the method <NUM>, the instrument positioning device <NUM> that is coupled to the medical instrument <NUM> is moved (e.g., advanced or retracted) to compensate for the compression determined at block <NUM>. In some instances, the instrument positioning device <NUM> advances the medical instrument <NUM> further into the patient's body to compensate for the determined compression. In one example, the distance advanced into the patient body is approximately equal to the determined compression. In another example, the distance advanced is less than the determined compression. In another example, the distance advanced is greater than the determined compression. As described below in section II. D, in embodiments that include telescoping medical instruments, one medical instrument can be retracted to compensate for the compression, the other medical instrument can be advanced to compensate for the compression, or one medical instrument can be advanced and the other medical instrument can be retracted to compensate for the compression.

In some embodiments, block <NUM> is performed substantially at the same time as the pull wire-based movement is executed. That is, the instrument positioning device <NUM> advances or retracts to compensate for the compression at substantially the same time as the pull wires are actuated to perform the pull wire-based movement. In some embodiments, this maintains or helps to maintain the correct or desired positioning of the distal portion <NUM> of the elongated shaft <NUM> throughout the commanded pull wire-based movement.

In some embodiments, the blocks <NUM>, <NUM>, <NUM> of the method <NUM> can be performed in a loop to provide compression compensation for each newly commanded pull wire-based movement of the medical instrument.

The method <NUM> can include other blocks or steps in addition to those illustrated. In some embodiments, not all illustrated blocks of the method <NUM> need be implemented.

The compression of the elongated shaft <NUM> can be determined, calculated, or estimated using one or more compression compensation parameters. The compression compensation parameter may be determined during a calibration of the medical instrument <NUM>. Example calibration methods and processes, during which the compression compensation parameter can be determined, are described below in section II.

The compression compensation parameter can be specific to a particular or specific medical instrument <NUM>. That is, for a specific medical instrument <NUM>, the compression compensation parameter can be determined during calibration of that particular medical instrument <NUM>. In this way, the compression compensation parameter can account for the unique properties (caused by, for example, material variation, manufacturing process variation, etc.) of that particular medical instrument <NUM>. The compression compensation parameter can be associated with the particular medical instrument <NUM>. For example, the compression compensation parameter can be stored in a memory or non-transitory computer readable medium of the medical instrument <NUM>. In some embodiments, the compression compensation parameter is stored in a remote database and associated with the particular medical instrument <NUM> such that it can be accessed and used to determine compression when the particular medical instrument <NUM> is used.

In another example, the compression compensation parameter can be specific to a class, batch, or model of similar medical instruments <NUM>. That is, the same compression compensation parameter can be used for a class, batch, or model of similar medical instruments <NUM>. In some embodiments, a single or several medical instruments <NUM> are calibrated to determine a compression compensation parameter that will be used by a larger group of similar medical instruments <NUM>.

In some embodiments, the compression compensation parameter is determined using a model that, for example, takes into account, for example, the material properties and dimensions of the medical instrument <NUM>. In one example, the elongated shaft <NUM> of the medical instrument <NUM> can be divided into one or more sections that can be modeled using Euler-Bernoulli beam theory.

The compression compensation parameter can be a value, factor, or parameter that relates a characteristic of the pull wire-based movement to axial compression. As one example, the compression compensation parameter can relate an angle of articulation of the elongated shaft <NUM> of the medical instrument <NUM> to axial compression. For example, the compression compensation parameter can relate x degrees of articulation of the elongated shaft <NUM> to y millimeters of axial compression. The compression compensation parameter can relate a commanded angle of articulation to axial compression. In another example, the compression compensation parameter can relate a measured angle of articulation to axial compression. In some instances, the angle of articulation is measured using spatial sensors (such as EM sensors), shape-sensing fiber, medical imaging (e.g., fluoroscopy), or other methods.

In another example, the compression compensation parameter can relate tension in a pull wire to axial compression of the elongated shaft <NUM>. The medical instrument <NUM> may include one or more tension sensors for measuring the tension in the pull wires.

In another example, the compression compensation parameter can relate displacement (e.g., linear displacement) of a pull wire to axial compression of the elongated shaft <NUM>. The medical instrument <NUM> may include a linear actuator for actuating the pull wire. The compression compensation parameter can relate linear movement of the actuator or the pull wire to axial compression of the elongated shaft <NUM>. For example, the compression compensation parameter can relate x millimeters of linear displacement of the pull wire or actuator to y millimeters of axial compression.

In some embodiments, the medical instrument <NUM> comprises rotational actuators that actuate the pull wires. For example, the pull wires may be mounted on pulleys which are rotated to actuate the pull wires. The compression compensation parameter can relate rotation of a pulley around which the pull wires are wound to axial compression of the elongated shaft. For example, the compression compensation parameter can relate x degrees of rotation of the pulley to y millimeters of axial compression.

In the above-cited examples, the compression compensation parameter is a parameter that linearly relates a characteristic of pull wire-based movement to axial compression. This need not be the case in all embodiments. For example, in some embodiments, the compression compensation parameter can comprise a function that relates the characteristic of pull wire-based movement to axial compression, wherein the function is non-linear.

In some embodiments, only a single compression compensation parameter is associated with the medical instrument <NUM>. In some embodiments, multiple compression compensation parameters are associated with the medical instrument <NUM>. For example, different compression compensation parameters can be associated with each of the different pull wires. As another example, different compression compensation parameters can be used to compensate for pull wire-based movements in different directions. As another example, multiple compression compensation parameters could be used to model non-linear compression of the elongated body <NUM>, using, for example polynomial, exponential, or other non-linear functions. In some instances, the number of compression parameters and/or the type of function (linear or non-linear) can be varied to closely model the relationship of compression to the input.

As described above, the compression compensation parameter can be used to relate one or more characteristics of pull wire-based movement to axial compression. Thus, the compression compensation parameter can be used to determine, calculate, or estimate axial compression of the elongated shaft <NUM> for a given pull wire-based movement. In some embodiments, the compression compensation value is used at block <NUM> of the method <NUM> described above.

Although the descriptions above have focused primarily on a single medical instruments, the compression compensation methods and systems described herein can be applied in systems that include telescoping medical instruments, such as, for example, systems that include a second medical instrument that telescopes within a working channel of a first medical instrument. The systems and methods may also be applied in systems that include more than two (e.g., three, four, five, or more) telescoping medical instruments.

<FIG> illustrates an embodiment of a second medical instrument <NUM> telescoping within a working channel <NUM> of a first medical instrument <NUM>. In the illustrated embodiment, the first medical instrument <NUM> is configured as previously described, including an elongated shaft <NUM> and an instrument base <NUM>. The elongated shaft <NUM> includes a working channel <NUM> extending therethrough. The first medical instrument <NUM> is coupled to a first instrument driver <NUM> of a first instrument positioning device <NUM>. The first instrument positioning device <NUM> is configured to move to advance or retract the first medical instrument <NUM>.

The second medical instrument <NUM> is configured similar to the first medical instrument <NUM>, including an elongated shaft <NUM> extending between a distal portion <NUM> and a proximal portion <NUM>. The proximal portion <NUM> is connected (either removably or permanently) to a second instrument base <NUM>. The second instrument base <NUM> is coupled to a second instrument driver <NUM> of a second instrument positioning device <NUM>. The second instrument positioning device <NUM> is configured to move to advance or retract the second medical instrument <NUM>.

As shown, the elongated shaft <NUM> of the second medical instrument <NUM> extends through the working channel <NUM> of the first medical instrument <NUM>. The second instrument positioning device <NUM> is configured to move to advance or retract the second medical instrument <NUM> through the working channel <NUM> of the first medical instrument <NUM>. Although not illustrated, in some examples, the second medical instrument <NUM> may also include a working channel for receiving a third medical instrument.

In the configuration illustrated in <FIG>, the distal portion <NUM> of the second medical instrument <NUM> is aligned with the distal portion <NUM> of the first medical instrument <NUM>. In some instances, this may be a preferred configuration for driving the medical instruments <NUM>, <NUM>. For example, the first and second medical instruments <NUM>, <NUM> can be in this configuration (with distal portions <NUM>, <NUM> aligned or flush) as they are navigated through the body to a target site.

The first medical instrument <NUM> can include pull wires for controlling the articulation, shape, and/or pose of the first elongated shaft <NUM>. The second medical instrument <NUM> can include pull wires for controlling the articulation, shape, and/or pose of the second elongated shaft <NUM>. In other examples, the first medical instrument <NUM> can be a passive instrument that does not include pull wires (i.e., a non-steerable instrument) or the second medical instrument <NUM> can be a passive instrument that does not include pull wires (i.e., a non-steerable instrument).

<FIG> depicts an example of axial compression of the first and second medical instruments <NUM>, <NUM> caused by pull wire-based movement. In the illustrated example, the first and second medical instruments <NUM>, <NUM> are articulated from the position shown in <FIG> to an angle shown in <FIG>. Either or both the first and second medical instruments <NUM>, <NUM> can experience compression. In the position illustrated in <FIG>, the second elongated shaft <NUM> extends outwardly from the distal end <NUM> of the first elongated shaft <NUM>. This may be caused by the axial compression of the first and/or second elongated shafts <NUM>, <NUM>. This may be undesirable. For example, as noted above, it is often desirable to drive the first and second medical instruments <NUM>, <NUM> with the distal ends <NUM>, <NUM> positioned flush.

<FIG> illustrates that the axial compression illustrated in <FIG> can be compensated for by moving the first and/or the second instrument positioning devices <NUM>, <NUM> to compensate. To compensate for axial compression, and return the distal portions <NUM>, <NUM> to a flush position, the system can either move the first instrument positioning device <NUM> a distance D1 in the direction indicated to advance the first medical instrument <NUM>, move the move the second instrument positioning device <NUM> the distance D2 in the direction indicated to retract the second medical instrument <NUM>, or perform a combined movement of the first and second instrument positioning devices <NUM>, <NUM> to both advance the first medical instrument <NUM> and retract the second medical instrument <NUM>.

In one example, a "compression compensation ratio" (CCR) can be defined or set for each medical instrument <NUM>, <NUM>. The CCR can be a value between zero and one. The CCR is one when the compressed medical instrument compensates fully for its own compression and zero when the reciprocal medical instrument (which may be uncompressed or may also be articulated and compressed) is moved to fully compensate for compression of the compressed medical instrument. Using the CCR for each medical instrument it is possible to define equations for defining the movement or insertion of the first and second medical instruments <NUM>, <NUM>, as follows: <MAT> <MAT>.

Using the principals and equations described above, as well as CCRs for each medical instrument <NUM>, <NUM>, it is possible to compensate for compression of the first and/or second medical instrument <NUM>, <NUM> by moving only the first medical instrument <NUM>, by moving only the second medical instrument <NUM>, or by moving both medical instruments <NUM>, <NUM>.

In some embodiments, retractions (CCR = <NUM>) of the first and second medical instruments <NUM>, <NUM> are preferred. For example, in some instances, retractions of the first and second medical devices <NUM>, <NUM> may be safer than insertions of the medical instruments. In some embodiments, however, insertions (CCR = <NUM>) are possible. Additionally, CCRs between zero and one can also be used.

Additionally, the CCR values can influence the spatial path taken by the distal portion <NUM>, <NUM> of the first and second medical devices <NUM>, <NUM>. For example, a CCR of one may correspond to a more spherical path, while a CCR of zero may create a more obtuse path (along an ellipsoid instead of a sphere). In some embodiments, the CCR value can be adjusted so that an optimal path can be tuned empirically. In some instances, the CCR value is adjusted during device calibration to deliver a target motion path of the distal tip of the elongated body <NUM>. During calibration, adjustment can be performed either manually or automatically through analysis of tip path.

<FIG> illustrates an embodiment of a medical instrument <NUM> configured to compensate for axial compression. In the illustrated embodiment, the medical instrument <NUM> is configured as described above, including, for example, an elongated shaft <NUM> extending between a distal portion <NUM> and a proximal portion <NUM>. The elongated shaft <NUM> may include one or more pull wires for articulating the elongated shaft. The elongated shaft <NUM> is connected to an instrument base <NUM>. The instrument device <NUM> is configured to couple to an instrument driver <NUM> of an instrument positioning device <NUM>. The instrument positioning device <NUM> can be configured to move the medical instrument <NUM> to advance or retract the elongated shaft <NUM> within a patient.

As illustrated, for some embodiments, the medical instrument <NUM> includes a computer readable medium <NUM>. The computer readable medium <NUM> can be positioned on or within the instrument base <NUM>. In another example, the computer readable medium <NUM> can be positioned on or within the elongated shaft <NUM>.

The computer readable medium <NUM> can store information associated with the medical instrument <NUM>. For example, the computer readable medium <NUM> can store one or more compression calibration parameters as discussed above in section II.

The computer readable medium <NUM> can include a computer readable code which can be read by another device. For example, the computer readable code can be a radio frequency identifier (RFID) tag. Data stored in the computer readable medium <NUM>, such as the compression compensation parameter, can be accessed by another device by scanning the RFID tag with an RFID reader. Other types of computer readable codes may also be used, such as bar codes, QR codes, etc..

The medical instrument <NUM> can include communication circuitry for communicating data stored in the computer readable medium <NUM> to other devices. Such communication circuitry may be wired or wireless.

The medical instrument <NUM> can include one or more EM sensors <NUM>. The EM sensors <NUM> are positioned on or within the elongated shaft <NUM>. As illustrated, an EM sensor <NUM> is positioned at the distal portion <NUM> of the elongated shaft <NUM>. The EM sensors <NUM> may be configured to provide position and/or orientation data about the medical instrument <NUM>. The EM sensors <NUM> provide position and/or orientation data relative to an externally generated EM field. Other types of spatial sensors can also be included.

The medical instrument <NUM> can include a shape-sensing fiber <NUM>. The shape-sensing fiber <NUM> may extend along or within the elongated shaft <NUM>. The shape-sensing fiber <NUM> can provide data related to the shape, articulation, or pose of the medical instrument <NUM>.

The medical instrument <NUM> can include one or more tension sensors associated with the one or more pull wires. The tension sensors can be configured to provide tension data for the one or more pull wires. In some embodiments, the tensions sensors are positioned in the instrument base <NUM>.

<FIG> is a block diagram depicting a system <NUM> configured to compensate for compression of medical instruments <NUM>, <NUM>. In the illustrated embodiment, the system <NUM> includes a processor <NUM> (or a plurality of processors) connected to a memory or computer readable medium <NUM> (or a plurality of computer readable media). The computer readable medium <NUM> can include instructions that can be executed by the processor <NUM> to control the system <NUM>.

In the illustrated embodiment, the system <NUM> includes a first instrument positioning device <NUM> coupled to a first medical instrument <NUM>. The first medical instrument <NUM> includes a computer readable code <NUM>. The first instrument positioning device <NUM> includes a code reader <NUM>. The code reader <NUM> is configured to read the computer readable code <NUM> on the first medical instrument <NUM>. In some embodiments, the computer readable code <NUM> is an RFID tag and the reader <NUM> is a RFID reader. The computer readable code <NUM> can store data related to the first medical instrument <NUM>, such as compression compensation parameters. The code reader <NUM> can read the data from the machine readable code <NUM>. In some embodiments, the data read from the computer readable code <NUM> can be communicated to the processor <NUM> for use in controlling the system <NUM>.

The system <NUM> may also include additional instrument positioning devices coupled to additional medical instruments. For example, as illustrated, the system <NUM> includes a second instrument positioning device <NUM> coupled to a second medical instrument <NUM>. The second instrument positioning device <NUM> includes a reader <NUM> configured to read a machine readable code <NUM> on the second medical instrument <NUM> in the manner previously described.

In some embodiments, the system <NUM> compensates for compression in the first and second medical instruments using the method <NUM> described above.

In some embodiments, the second medical instrument <NUM> telescopes within a working channel of the first medical instrument <NUM>. The system <NUM> may use the CCRs described above to compensate for compression as described in section II.

The computer readable medium <NUM> can include instructions that configure the processor <NUM> to cause the system <NUM> to determine, based at least in part on information indicative of a pull wire-based movement of an elongated shaft <NUM> of a first medical instrument <NUM> and a compression compensation parameter, an axial compression of the elongated shaft <NUM> of the first instrument <NUM>. The compression compensation parameter can be read, using the reader <NUM>, from the computer readable code <NUM>. The instructions can further be configured to move the first instrument positioning device <NUM> connected to the first medical instrument <NUM> to compensate for the axial compression of the first elongated shaft.

The compression compensation parameter can be determined during a calibration process of the medical instrument <NUM>. The calibration process can include articulating the medical instrument to a first position with a pull wire-based movement, determining the compression of the medical instrument, and relating a characteristic of the pull wire-based movement to the determined compression to determine the compression compensation parameter.

The calibration process can include articulating the medical instrument <NUM> to a variety of different positions and determining compression and compression compensation parameters for each. In some embodiments, a single compression compensation parameter is derived from the variety of different articulated positions.

The calibration process can include attaching one or more spatial caps to the medical instrument <NUM>. The one or more spatial caps can be calibrated to provide valid metrology or measurement of the pose (e.g., position and/or orientation) of the medical instrument <NUM>. In some instances, the one or more spatial caps are calibrated to provide metrology or measurement or pose of the distal tip of the elongated body <NUM> of the medical instrument <NUM>. The spatial caps can include spatial sensors, such as EM sensors, that provide position and/or orientation data about the articulation, pose, or position of the medical instrument <NUM>. The spatial caps can be used to measure the articulation and/or compression of the medical instrument <NUM>. The one or more spatial caps can be used to further validate the spatial sensors included on the medical instrument <NUM>.

In other embodiments, feedback from an imaging device included on the medical instrument <NUM> (for example, at a distal tip of the elongated body) can be analyzed using an external tracking device to estimate tip pose instead of or in addition to the use of the one or more spatial caps. Triangulation, projection or direct or manual measurement (e.g., using a protractor) methods can also be used in addition to or in place of the one or more spatial caps.

The articulation and/or compression of the medical instrument <NUM> can be determined from spatial sensors positioned on the medical instrument <NUM> itself. For example, the articulation and/or compression can be determined using EM sensors or shape-sensing fiber as previously described.

<FIG> is a flow chart illustrating an example method <NUM> for calibrating a medical instrument <NUM>. The method <NUM> begins at block <NUM>, where a pull wire-based movement is performed to move the elongated shaft <NUM> to a first position. In some instances, articulating the elongated shaft <NUM> comprises tensioning, pulling, or otherwise actuating a pull wire connected to a distal portion <NUM> of the elongated shaft <NUM>.

The method <NUM> continues at block <NUM>, where a characteristic of the pull wire-based movement is determined. In some instances, determining the characteristic of the pull wire-based movement can include pull wire tension, pull wire displacement, actuator displacement, commanded angle of articulation, measured angle of articulation, etc..

In some examples, the method <NUM> further includes attaching one or more spatial caps to the distal portion <NUM> of the elongated shaft <NUM>. The one or more spatial caps can be configured to provide spatial data about the location and orientation of the distal portion <NUM> of the elongated shaft <NUM>. In some embodiments, determining the pull wire-based movement comprises analyzing the spatial data from the spatial cap. In some embodiments, the one or more spatial caps include one or more EM sensors. In some embodiments, determining the pull wire-based movement comprises measuring an angle of the elongated shaft.

At block <NUM>, with the elongated shaft <NUM> in the first position, the compression of the elongated shaft <NUM> is determined. In an example, determining the compression can include analyzing the spatial data from the spatial cap. In another example, the elongated shaft <NUM> comprises a spatial sensor configured to provide spatial data about the location and orientation of the distal portion <NUM> of the elongated shaft <NUM>, and determining the pull wire-based movement includes analyzing the spatial data from the spatial sensor. In another example, determining the axial compression comprises measuring a length of the elongated shaft.

At block <NUM>, a compression compensation parameter is determined by relating the first position to the determined compression of the elongated shaft <NUM>. In some embodiments, the method <NUM> further includes storing the compression compensation parameter in a non-transitory computer readable medium of the first medical instrument <NUM>.

Implementations disclosed herein provide systems, methods and apparatus for compensating for compression in elongated shafts of medical instruments. Compression can be determined, in some instances, using a compression compensation parameter determined during calibration of the medical instrument, and compensated for by moving the medical instrument with an instrument positioning device coupled thereto.

It should be noted that the terms "couple," "coupling," "coupled" or other variations of the word couple as used herein may indicate either an indirect connection or a direct connection. For example, if a first component is "coupled" to a second component, the first component may be either indirectly connected to the second component via another component or directly connected to the second component.

The phrases referencing specific computer-implemented processes/functions described herein may be stored as one or more instructions on a processor-readable or computer-readable medium. The term "computer-readable medium" refers to any available medium that can be accessed by a computer or processor. By way of example, and not limitation, such a medium may comprise random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory, compact disc read-only memory (CD-ROM) or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. It should be noted that a computer-readable medium may be tangible and non-transitory. As used herein, the term "code" may refer to software, instructions, code or data that is/are executable by a computing device or processor.

In other words, unless a specific order of steps or actions is required for proper operation of the method that is being described, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.

As used herein, the term "plurality" denotes two or more. For example, a plurality of components indicates two or more components.

Claim 1:
A robotic system (<NUM>, <NUM>, <NUM>), comprising:
a first medical instrument (<NUM>, <NUM>, <NUM>, <NUM>) configured for insertion, in use, into a lumen of a patient, the first medical instrument comprising: a first elongated shaft (<NUM>, <NUM>, <NUM>), a first pull wire (<NUM>, <NUM>) actuable to cause pull wire-based movement of the first elongated shaft, and a first instrument base (<NUM>, <NUM>, <NUM>) including a first drive input (<NUM>, <NUM>) for actuating the first pull wire;
a robotic arm (<NUM>) attached to the first instrument base and configured to move to advance or retract the first medical instrument through the lumen of the patient;
at least one non-transitory computer readable medium (<NUM>, <NUM>) having stored thereon executable instructions; and
at least one processor (<NUM>) in communication with the at least one non-transitory computer readable medium and configured to execute the instructions to cause the robotic system to at least:
determine an axial compression of the first elongated shaft;
determine a distance to move the robotic arm to compensate for the determined axial compression of the first elongated shaft; and
move the robotic arm to either advance or retract the first elongated shaft of the first medical instrument through the lumen of the patient by the determined distance.