Device

Abstract

Aspects of the present disclosure provide a surgical robot (10) deployed in a body lumen inside a human or animal subject, the robot comprising: an inflatable frame (12) having a folded state for delivery to a target site in the lumen and an inflated state in which the frame defines an open cavity (18); a manipulator (14) movable within the cavity for operating a medical device; and a soft actuator (16) operable by fluid pressure to move the manipulator (14) by applying force between the frame (12) and the manipulator, the frame (12) being positioned around the soft actuator (16) to provide protection between the soft actuator and the body lumen.

Description

Technical Field

[0001] The present invention relates to an apparatus and a method, and more particularly, to a robot for performing medical procedures such as procedures involving deployment in a body lumen inside a human or animal subject, and more particularly, the robot may be used in minimally invasive procedures such as those performed using an endoscope.

Background Art

[0002] Colorectal cancer was estimated to have resulted in the second highest cancer - related deaths and the third highest incidence globally in 2020. As a result, research has been intensely focused on the development of improved screening and treatment options.

[0003] Among the recently developed surgical techniques for early - stage colorectal cancer, endoscopic submucosal dissection (ESD) offers patients advantages such as a reduced recurrence rate, the possibility of en - bloc removal of large early - stage cancers, and an improved resection rate, compared to endoscopic mucosal resection (EMR), which is a more common procedure.

[0004] However, as a result of the high technical difficulty, the procedure time and the perforation rate are higher for ESD. Robot devices may simplify difficult ESD procedures, alleviate the learning curve, and / or reduce the personnel required, but despite recent advancements, a standard flexible robotic endoscope does not exist. Challenges faced by designers of robot devices include reducing patient discomfort and achieving a cecal intubation rate equivalent to that of standard endoscopy. Cecal intubation is achieved when an endoscopist successfully reaches the cecum using an endoscope, and a bulky robotic mechanism may make guidance and insertion more difficult, increasing patient discomfort and potentially resulting in the need for sedation or a longer procedure time.

[0005] One possible solution to this problem is proposed in a conference paper titled "Pop-Up Soft Robot for Minimally Invasive Surgery" (Mark Runciman, James Avery, George Mylonas; Hamlyn Centre, Imperial College London, London, UK; Hamlyn Symposium on Medical Robotics 2022). [Overview of the Initiative]

[0006] This disclosure aims to provide a soft robot that can be operated by pneumatic or hydraulic actuators and can provide improved control of end effectors.

[0007] The aspects and examples of the present invention are described in the claims and aim to address this technical problem and other technical problems.

[0008] This disclosure provides a foldable soft robotic structure and actuators for controlling medical devices such as surgical instruments during ESD. This robot may be used in conjunction with a flexible endoscope.

[0009] In the embodiments, the robot of this disclosure is capable of applying force with high precision and high repeatability, and optionally also capable of detecting force.

[0010] The robotic structure may include a frame. The frame and actuators may be provided with low-profile polymer sheets, and a sealed, inflatable chamber is positioned between the sheets. The actuator may be referred to as a “bag actuator.” While this typically relates to a pneumatic actuator, this disclosure envisions a hydraulic actuation for improved control.

[0011] In one embodiment, a surgical robot deployed in a body lumen inside a human or animal subject is provided, the robot comprising: an inflatable frame having a folded state for delivery to a target site in the lumen and an inflated state in which the frame defines an open cavity; a manipulator movable within the cavity for operating a medical device; and a soft actuator operated by fluid pressure to move the manipulator by applying force between the frame and the manipulator, wherein the frame is positioned around the soft actuator so as to be positioned between the soft actuator and the body lumen when the frame inflates in the body lumen.

[0012] The soft actuator may be supported by a frame. For example, the soft actuator may be held by the wall of an open cavity. The soft actuator may be held on the inward-facing surface of the wall.

[0013] The frame may be configured to restrict the radial spread of the robot.

[0014] The application of fluid pressure to operate the actuator may result in longitudinal expansion or contraction of the actuator to move the manipulator. The actuator may be configured such that lateral expansion or contraction of the actuator during this operation (e.g., expansion of a bag-shaped actuator) is directed radially inward, away from the wall of the body lumen. This may help reduce the possibility of lumen perforation.

[0015] Furthermore, the framework may be positioned to protect the soft actuators from forces exerted by body tubular structures such as intestinal peristalsis.

[0016] Furthermore, the soft actuator may be positioned relative to the frame to suppress lateral deflection of the frame caused by the lateral force applied to the manipulator by the actuator.

[0017] Furthermore, the Disclosure provides a surgical robot deployed in a body lumen inside a human or animal subject, the robot comprising: an inflatable frame having a folded state for delivery to a target site in the lumen and an inflated state in which the frame defines an open cavity; a manipulator movable within the cavity for operating a medical device; and a soft actuator fixed to the frame for applying a lateral force by applying a force between the frame and the manipulator to move the manipulator radially outward in the cavity toward the frame, the soft actuator being positioned relative to the frame to suppress lateral deflection of the frame due to the lateral force.

[0018] Lateral deflection of the frame may be suppressed by fixing soft actuators to the frame and aligning them with the walls of the frame. For example, the soft actuators may be held on the surface of a wall so that the line of action of the force generated by the actuators is aligned with the wall. Alternatively, the actuators may be positioned so that the force generated by the actuators is perpendicular to the apex ridges (angles) of the frame structure. In this configuration, the tension from the actuators tends to compress the frame radially at the location of the actuators rather than causing longitudinal buckling of the frame.

[0019] The soft actuator may be located in an open cavity of the frame on the proximal side of the manipulator.

[0020] The soft actuator may be capable of extending and contracting along the surface of the wall in order to apply force to move the manipulator. For example, the wall may be straight.

[0021] The actuator link mechanism may be connected between the manipulator and the soft actuator and routed via a line guide element, which is fixed to the frame and configured to guide the control line of the link mechanism so as to be movable around the curved section.

[0022] The linkage mechanism may be fixed to the frame by actuators. The actuators may be flexibly fixed by tethers. The tethers may be connected to the vertices of the frame.

[0023] The link mechanism may be configured to allow for pulley placement. For example, the link mechanism may include a movable member and at least a line guide element positioned on the movable member. The line guide element may be configured to guide the control line of the link mechanism movably around the curved section.

[0024] The control lines of the linkage mechanism are connected to the manipulator to move the manipulator and routed through at least one line guide element positioned on the movable member.

[0025] The control lines connected to the manipulator may, for example, be fixed to the frame at the vertices of the frame.

[0026] The frame comprises several elongated, expandable pillars aligned with one another between adjacent vertices of the frame. The pillars may be straight. In some embodiments, curved pillars may be used.

[0027] The frame may have a one-piece structure formed integrally from two laminated sheets of flexible material, for example, the laminated sheets may be configured to fold, and as a result the fold provides the apex of the frame. An opening may be provided along the apex of the frame, and a line guide element having a channel for guiding a control line may be held in the opening by a clip. The channel of the line guide element may be lined with a smooth material to reduce friction as the control line travels through the line guide element. Thus, the line guide element may provide the function of a pulley or capstan.

[0028] The sheet comprises a row of openings configured to be arranged along the apex of the framework between adjacent pillars. At least one of the openings may function to fix the soft actuator to the apex. The clip may extend through one or more of the openings to fix the soft actuator.

[0029] The sheets forming the framework may be held together by a linear connection region 40 such as a welded joint. The linear connection region 40 may extend between the openings 42 and demarcate the non - connected regions of the sheets. When fluid pressure is applied between the sheets, the non - connected regions expand to form a pillar having an opening between the pillars at the apex of the framework.

[0030] The framework may comprise a first fluid port 44 arranged to supply expansion fluid to the framework and may also hold a second fluid port that may be arranged to convey the expansion fluid inside the framework to the soft actuator.

[0031] The manipulator may comprise a shaft rotatably mounted within the cavity. The shaft may be arranged such that an elongate medical device can be arranged through the lumen of the shaft. Examples of medical devices include surgical tools having an end effector arranged at the distal end of an elongate flexible body.

[0032] The manipulator shaft holds an extension that can be extended axially forward and backward from the cavity. Accordingly, both the shaft and the extension provide an extendable rigid member.

[0033] The framework holds a bendable connection portion arranged to flexibly support a part of the elongate medical device at the proximal side of the shaft, and the part of the medical device held by the shaft is rotatable.

[0034] The bendable connection portion may be configured to allow the elongate medical device to advance and retract.

[0035] The shaft may hold an instrument connector configured to removably hold an elongated medical device relative to the shaft at a selected axial position.

[0036] The device connection section may connect the elongated medical device to the shaft such that the forward movement of the elongated medical device results in an extension of the shaft's extension.

[0037] Both the soft actuator and the frame may be arranged as a layered structure, for example, wrapped or coiled, so that they fold into a folded state for delivery to the target site. Alternatively, the soft actuator and the frame may be arranged to unfold from a folded state as they expand.

[0038] Therefore, it can be recognized that the robotic arm controlling the end effector of a surgical instrument is provided by a robotic manipulator. This manipulator is moved by controlling control lines, such as wires or cables, attached to actuators held by a frame.

[0039] The frame, when expanded, may function to stabilize the manipulator within the body cavity into which it is deployed. The frame may also hold line guide elements (e.g., pulleys, capstans, etc.) that guide a control line between the actuator and the manipulator. The control line may provide a mechanical actuation force to the frame to move the medical device held by the manipulator. Both the manipulator and the control line may be located inside an open cavity of the frame, and the actuator may also be located inside the same cavity. Typically, the actuator is located proximal to the manipulator. The manipulator may comprise a rigid shaft positioned to rotate relative to a bendable or rotatable coupling located proximal to the manipulator in the frame. The bendable or rotatable coupling may be configured to allow a portion of the medical device to be rotatably connected to the frame proximal to the manipulator. This may allow the movement of the manipulator by the control line to achieve a clearly defined displacement, along with known mechanical advantages.

[0040] Typically, the actuator is housed inside this framework, and for example, the framework may surround and protect the actuator inside a cavity within the framework. The actuator may be controlled by controlling the pressure of a fluid (gas or liquid) that fills the actuator. This fluid pressure (for example, the pressure inside the actuator) may be used to estimate the force exerted on the end effector). This feedback allows for precise movement control of the manipulator. In prior art devices, this may be impossible due to the movement of body lumens (such as intestinal peristalsis) which can deform the actuator and result in undesirable and unpredictable pressure changes.

[0041] The actuator may be considered a “muscle.” Similarly, the support structure of the device, referred to herein as the frame, is pressurized with fluid and functions as a “skeleton” that allows the actuator to exert force on the robotic arm.

[0042] Embodiments of the present disclosure enable localized cable movement driven by a distal pressurized fluid tube. These embodiments may not face the same problems as conventional Bowden cables. Specifically, the curvature of the colon can make it difficult to predict the movement of the end effector using a Bowden cable, and generally, devices using Bowden cables are limited to the sigmoid colon / descending colon. In contrast, embodiments of the present disclosure may be able to access the entire colon with comparable end effector functionality.

[0043] The embodiment provides surgeons with the integration of natural / natural movement and haptics when performing procedures. For example, in the embodiment, haptic feedback is provided in the device's control interface based on the fluid pressure in the actuator.

[0044] Embodiments of the present disclosure are configured to enable control of any conventional surgical tool. For example, the tool may be passed through a manipulator shaft of a device described herein so that the surgical tool can be manipulated.

[0045] The embodiment may be configured to accommodate any "off-the-shelf" flexible endoscopic instrument, the instrument which may be replaced while maintaining the operating channels and functions of the endoscope.

[0046] The actuator and / or framework may be made from a sheet of flexible material such as a thin-film polymer. This may enable the use of the actuator and / or framework in small incisions or natural orifices, while also allowing for low-profile pop-up functionality (with the possibility of tissue retraction for stabilization) and MRI compatibility.

[0047] The embodiments of this disclosure primarily relate to medical and surgical applications. However, the "skeleton" of the framework and the "muscles" of the actuators may be used in environments other than gastrointestinal surgery where precise and accurate movement is required in small, hard-to-reach places.

[0048] These advantages and numerous other advantages relating to this disclosure will become apparent to those skilled in the art. [Brief explanation of the drawing]

[0049] Embodiments of the present disclosure will be described in detail here with reference to the accompanying drawings. [Figure 1] Figure 1 shows an isometric view of the surgical robot relating to this disclosure. [Figure 2] Figure 2 shows a schematic diagram of an actuator and actuator link mechanism used in a robot, such as the one shown in Figure 1. [Figure 3] Figure 3 shows a side view of a robot, such as the one shown in Figure 1. [Figure 4] Figure 4 shows a partially disassembled robot, such as the one shown in Figure 1. [Figure 5] Figure 5 is a flowchart showing how the device works.

[0050] In drawings, similar reference numbers are used to indicate similar elements. [Modes for carrying out the invention]

[0051] Figure 1 shows a surgical robot 10, which comprises an inflatable frame 12, manipulators 9, 11, and 14, and a soft actuator 16 (not visible in Figure 1). The soft actuator is connected to the manipulator 14 by a linkage mechanism 20 (shown in Figure 2) which includes a control line 15.

[0052] The frame 12 surrounds at least the proximal portions of the manipulators 9, 11, and 14, which are positioned to protrude distally from the open distal end face of the open cavity 18 provided by the frame 12.

[0053] The manipulator may comprise a manipulator connector 14 and shafts 9 and 11. Typically, the manipulator shaft comprises a rotatably mounted shaft portion 11 capable of holding the manipulator connector 14, and an extendable portion 9 (as shown in Figure 3). The manipulator connector 14 is connected to a plurality of control lines 15 that suspend the manipulator connector 14 near the open distal end face of the frame.

[0054] The frame 12 comprises a triangular structure, such as a triangular prism. This prism defines an internally open cavity 18, which is surrounded by the expandable walls of the frame 12. Each wall of the frame 12 comprises multiple expandable sections that are joined together to form a wall. These sections are configured to expand so that the wall can become at least semi-rigid. The walls together enclose the sides of the cavity 18. The expandable sections of the frame 12 are configured to be fluidly connected to a pressurized fluid source that expands the frame. When expanded, these sections may form "pillars" of the frame, which may be linear in shape.

[0055] The expansion pressure of the framework may be selected such that the expansion walls of the framework are at least semi-rigid. For example, the pressure may be selected such that the expansion walls are rigid enough to provide protection for the cavity 18 against forces such as intestinal peristalsis associated with the expansion of a human or animal subject's body lumen.

[0056] An inflatable section of the wall is configured such that when the section contracts, the framework can be folded (e.g., rolled up). The folding configuration may provide a suitable arrangement for allowing a robot to be held on or located within the shaft of a minimally invasive medical device, such as an accessory for an endoscope.

[0057] This may allow the robot to be transported to a target site in the patient's body lumen in order to perform minimally invasive procedures.

[0058] As described above, the robot frame shown in Figure 1 is arranged such that control lines 15 provide three lateral connections to the manipulator coupling 14. The control lines 15 may be angularly separated around the manipulator so that the manipulator coupling 14 can be controlled to move in two dimensions (e.g., up and down, left and right) by applying tension to the control lines. Thus, the manipulator coupling 14 is connected to each of the three vertices of the triangular frame 12 by three separate control lines 15, with one line 15 at each vertex. Each control line 15 is connected to the manipulator coupling 14 at one end and then routed to the corresponding actuator 16 via the corresponding vertex of the frame 12.

[0059] Typically, the actuator 16 comprises an inflatable structure configured to contract longitudinally when it expands. In other words, a structure in which lateral expansion results in longitudinal contraction, and vice versa. One way of providing such a structure is shown in Figure 2. As shown in Figure 2, the actuator 16 may comprise a series of flat hexagonal chambers, which are formed between two flexible sheet elements joined at their edges in a line to form a flat shape having a bellows-like shape in plan view. The flexible sheet elements may be made of a flexible but substantially non-extendable material. As a result, during expansion, the lateral (outward) expansion of the sheet elements results in an overall longitudinal contraction of the actuator. Typically, the actuator can contract at a fixed rate over its entire length.

[0060] The actuator 16 may be protected by the frame, for example, the actuator 16 may be located in an open cavity 18, and may be positioned proximal to the manipulator coupling within the cavity. For example, the actuator 16 may be held by the inner surface of the wall of the frame 12. This may provide both protection for the actuator 16 and support for the actuator 16.

[0061] The actuator is connected at one end to the vertex of the frame 12 by a tether 26. The other end of the actuator 16 is connected to the manipulator 14 by a control line 15. The control line is routed to the manipulator 14 via one or more line guide elements 22, 24. The combination of the guide members and the control line 15 may provide an actuator linkage mechanism that enables the operation of the actuator that moves the manipulator. Thus, it can be recognized that each control line 15 may be controlled independently by the corresponding actuator 16 of each control line 15. The number of control lines 15 and the number of actuators 16 may vary according to the desired nature and degree of manipulator position control. In some embodiments, at least one actuator and the actuator linkage mechanism are provided on the wall of each frame, and the control wires 15 of each actuator linkage mechanism are routed to the manipulator connection 14 via guide elements located at vertices of the frame that are different from the vertices of other control wires.

[0062] Generally, the actuator 16 may be aligned with the frame wall, for example, the actuator 16 may be flat with respect to the inner surface of the frame wall. The actuator 16 is tethered at one of the vertices, and a control line extends from the other end of the actuator toward a guide element at an adjacent vertex of the frame. In this configuration, the contraction of the actuator may exert a force aligned with the frame wall. The tether and control line may be positioned such that the force is substantially perpendicular to the vertex of the frame and lies in the plane of the wall. This is one way to ensure that the operation of the actuator does not result in longitudinal buckling of the frame structure or undesirable deflection of the manipulator.

[0063] The frame 12 includes a first fluid port positioned to supply expansion fluid to the frame. This may be connectable to the lumen of an elongated medical device such as a catheter. The frame may also hold a second fluid port for supplying expansion fluid to a soft actuator. The second fluid port may be located inside the frame 12.

[0064] As can be seen from Figure 1, soft actuators, such as those described above, are held in place on the inward-facing surface of the frame wall. The actuators may be protected by the frame from the lumen into which the robot is deployed. Conversely, the lumen wall itself is protected from the actuators by the frame wall. Therefore, it can be seen that a frame that functions to support a manipulator also functions to support and protect soft actuators.

[0065] In the case of a triangular frame such as a triangular prism shown in Figure 1, it can be recognized that the manipulator 14 may be connected to three separate control lines 15, each of which may be controlled by a separate corresponding actuator link mechanism and actuator 16. Each of these actuation configurations is located on a different internal wall of the frame. Here, one possible actuation configuration is illustrated with reference to Figure 2. In Figure 2, the frame 12 is not shown for clarity. However, typically, line guide elements 22,24 are located at the vertices of the frame, for example, spaced longitudinally along the length of the frame.

[0066] The line guide element may include a channel for guiding the control line, and the control line may be routed through the channel. The channel may include a tube and may be lined with a smooth material to facilitate the sliding of the control line through the channel. The line guide element may also provide the function of a pulley or capstan, allowing the control line to slide or advance around the line guide element to create a curve in the control line.

[0067] As illustrated, the operating configuration shown in Figure 2 comprises a tether 26, an actuator 16, a first control line 15', a second control line 15, a first line guide element 22, a second line guide element 24, a movable member 28, a third line guide element 30, a fourth line guide element 32, and a fifth line guide element 34. The tether 26 connects the rear side of the actuator 16 to the apex of the frame 12. The other end of the actuator 16 is connected to the first control line 15'. The first control line 15' is then routed to the first line guide element 22, which gives the first control line 15' a 90-degree curve. The first control line 15' is then routed to the second line guide element 24, which is located at the same apex of the frame 12, longitudinally spaced away from the first line guide element 22. The second line guide element 24 holds the first control line 15' through a further 90-degree curve, where the first control line 15' ends up connected to the movable member 28.

[0068] The movable member 28 holds the third line guide element 30. The third line guide element 30 is configured to bring a 180-degree curve to the line. The fourth line guide element 32 is positioned at an adjacent vertex on the opposite side of the frame. The second control line 15 is fixed at the vertex adjacent to the fourth line guide element 32 and then routed through the third line guide element 30 in the movable member before passing around the fourth line guide element 32, and optionally returning through the third line guide element 30 through a further 180-degree curve, from where the second control line 15 is routed back to the fourth line guide element 32. The control line then follows a further 90-degree curve around the fourth line guide element 32, from where the control line is routed along the vertex of the frame to the fifth line guide element 34. The fifth line guide element 34 brings a further curve to the second control line 15, allowing the second control line 15 to be connected to the manipulator 14.

[0069] Except for the portion of control line 15 that connects manipulator 14 to fifth line guide element 34, control lines 15, 15' may be positioned primarily along the surface of the walls of the frame 12 or along the vertices of those walls. This is one way that embodiments of the present disclosure may be arranged to reduce buckling of the frame (e.g., longitudinal deflection). It will also be understood that the actuator arrangement shown in Figure 2 provides a pulley arrangement of control lines. Other methods may be employed to provide mechanical advantages to actuator 16.

[0070] Here, a side view of a soft robot, such as the one shown in Figure 1, can be identified by referring to Figure 4. In this drawing, the walls of the frame 12 are shown as partially transparent to allow the position of the manipulators to be more clearly identified. As shown in Figure 4, the manipulators 14, 11, and 9 are provided with manipulator connectors to which control lines 15 can be connected. The manipulators 14, 11, and 9 are also provided with a shaft 11, which may be provided by a substantially rigid, elongated member having a lumen through which the shaft 11 passes. The medical device 7 may pass through this lumen so that the medical device 7 can be supported by the shaft 11 and controlled to be movable by the manipulator connector 14.

[0071] The device guide 3 may be provided, for example, connected to one of the vertices of the frame located towards the proximal end of the frame. The device guide 3 may allow the medical device 7 to be routed from the proximal end of the frame toward the shaft 11. The device guide 3 may be substantially flexible and / or rotatable so as to allow the device 7 to easily move forward and backward through the guide while also stabilizing the device relative to the frame.

[0072] The manipulator shaft 11 may include an extension 9 that extends from the distal end of the shaft 11 and is operable to retract. The extension and the shaft may be arranged concentrically so that both are extendable and one can extend from the other. Thus, it can be recognized that the extension and the shaft provide an extendable rigid member. The distal end of the extension may hold a device coupling configured to hook onto a part of a medical device arranged through the distal end. Examples of such arrangements include magnets, detents, spring latches, interfering matings, and other arrangements. This detachable coupling of the medical device 7 to the extendable portion 9 of the shaft 11 may allow the medical device 7 to move forward and backward, resulting in the corresponding extension or retraction of the manipulator shaft 11,9. Thus, it can be recognized that a flexible medical device may be rigidly supported along the extendable length of the distal end of the medical device. Combined with lateral control provided by control lines, 3D control of the medical device 7 may be provided. This could allow the end effector of the device to be manipulated in three dimensions.

[0073] The robot's movements will be explained here with reference to Figures 1, 2, and 3.

[0074] First, to prepare the device to be deployed, an elongated medical device suitable for deployment in a minimally invasive procedure is advanced through the instrument guide 3 and the manipulator shafts 7 and 9. Next, the frame and actuators are folded in a contracted state around the shafts of the medical device and the manipulator shafts. For example, the frame and actuators may be rolled up in a low-profile configuration. In this folded configuration, the robot advances the minimally invasive medical device to a target site in a human or animal patient. For example, the minimally invasive medical device may be advanced to the target site in an accessory channel of an endoscope or by similar means. Once the target site is reached, pressurized fluid is supplied to the frame to inflate the walls of the frame. The walls of the frame inflate until they are at least semi-rigid. Actuator linkage mechanisms connecting the manipulator and actuator, held by each of the walls, are positioned so that when the frame is fully inflated, the manipulator is held in place (such as in the center of an open cavity formed by the inflated frame). This may be done by appropriately selecting the length of the control line. If necessary, the medical device may be moved slightly forward or backward so that the device coupling at the distal end of shafts 7,9 engages with the medical device. Once this is done, the forward and / or backward movement of the medical device results in the corresponding extension or contraction of shafts 7,9. To produce lateral deflection of the medical device with respect to the medical instrument, pressurized fluid may be supplied to a selected actuator to produce lateral expansion of the actuator and the corresponding longitudinal contraction. This longitudinal contraction causes actuator 16 to pull the first control line 15'. Thus, the tension in the first control line 15' pulls the movable member 28 away from the fourth line guide element 32. Thus, the length of the second control line 15, which is wound around the third line guide element 30 (on the movable member (28)) and around the fourth line guide element 32, is extended. In the configuration shown in Figure 2, this provides a 4:1 mechanical advantage, but other force ratios may be provided by other types of configurations.This results in the corresponding movement of the manipulator 14 due to the tension in the second control line 15. In some embodiments, the mechanical advantages provided by the actuator linkage mechanism are selected based on the degree of longitudinal contraction of the corresponding actuator, such that the full operation of the actuator 16 corresponds to the movement of the manipulator 14 over substantially the entire range of available movement.

[0075] Since shafts 7 and 9 are rotatably connected between the manipulator 14 and the equipment connection part 3, it can be recognized that tension in the control wires allows for rotational / lever-like movement of shafts 7 and 9.

[0076] Advantageously, since the actuator 16 is positioned inside the frame (and thus protected by the frame), the actuator 16 is protected from external forces that may be applied to it during medical procedures. It will be understood that such external forces may result in deformation of the actuator, such as compression, which may cause undesirable movement or deflection of the manipulator. Thus, it can be recognized that one advantage of this disclosure is that it provides improved control of the manipulator. In addition, since the actuator is positioned to provide a lateral (e.g., perpendicular) force with respect to the longitudinal axis of the frame and / or medical device 7, the operation of the actuator is then less likely to result in buckling or lateral stress on the shaft of the medical device 7. This may also provide improved control of the manipulator 14.

[0077] Here, a diagram of the partially disassembled frame can be seen by referring to Figure 5. The frame may comprise two flat sheets of a material such as a polymer. Typically, the sheets are flexible but not extendable (e.g., neither ductile nor elastic). The two sheets may be held together in a layered structure, one on top of the other, with welds around the peripheral edges of the sheets, to provide an inflatable bag between the two sheets. A series of further welds may be provided to subdivide this bag into a set of compartments. The welds may comprise short, straight linear welds spaced apart across the width of the sheets and aligned with the length of the sheets. The straight linear welds may be divided into three sections, each section corresponding to one wall of the frame when expanded. Between the divisions in the welds, openings penetrating the sheets may be provided and positioned so that when the frame expands, the openings are at the apex of the frame. The opening at the vertex provides a fixed point for guide elements and / or control lines used to tether the actuator.

[0078] One advantage of using a fluid-actuated soft actuator is that measurements of the working fluid pressure can be used to estimate any external forces present on the robot's shaft. This is advantageous over cable-driven systems, which are subject to friction that is difficult to predict. For example, if a long force transmission cable were used to move the robot's shaft instead of a soft actuator, measuring the tension in the cable at the proximal end would not allow for an accurate force estimation due to the effects of friction along the length of the cable. This is especially true if the long cable passes through a highly curved path such as the colon / gastrointestinal tract. However, this would be possible with fluid acting, as the pressure in the supply tube would reach equilibrium after any movement, compensating for any height changes relative to the end of the supply tube.

[0079] Any feature relating to any one of the examples disclosed herein may be combined with any selected feature relating to any of the other examples described herein. For example, features of a method may be implemented in preferably configured hardware, and specific hardware configurations described herein may be employed in a manner that is implemented using other hardware.

[0080] From the above description, it will be understood that the embodiments shown in the figures are merely illustrative and include features that may be generalized, omitted, or replaced as described herein and in the claims. Generally referring to the drawings, it will be understood that schematic functional block diagrams are used to illustrate the functions of the systems and devices described herein. However, it will be understood that functions do not need to be divided in this manner and should not be interpreted as suggesting any specific hardware structure other than those described and claimed below. Furthermore, one or more functions of the elements shown in the drawings may be subdivided and / or distributed throughout the entire device of this disclosure. In some embodiments, the functions of one or more elements shown in the drawings may be integrated into a single functional unit.

[0081] The embodiments described above should be understood as illustrative examples. Further embodiments are conceivable. Any feature described in relation to any one embodiment may be used alone or in combination with other features described, or in combination with one or more features of any other embodiment or any combination of any other embodiments. Furthermore, equivalents and modifications not described herein may be adopted without departing from the scope of the invention as defined in the appended claims.

Claims

1. A surgical robot (10) deployed in a body cavity inside a human or animal subject, wherein the robot is An expandable frame (12) having a folded state for sending to a target location within the lumen, and an expanded state in which the frame defines an open cavity (18), A manipulator (14) that is movable within the cavity for operating a medical device, A fluid-pressure-operable soft actuator (16) is provided to move the manipulator (14) by applying force between the frame (12) and the manipulator. It has, The frame (12) is positioned around the soft actuator (16) to provide protection between the soft actuator and the body lumen. A surgical robot (10) characterized by the following features.

2. The soft actuator (16) is supported by the frame. The robot according to claim 1.

3. The soft actuator (16) is held by the wall of the open cavity (18), for example, the soft actuator is held on the inward-facing surface of the wall. The robot according to claim 1 or 2.

4. The aforementioned frame is configured to restrict the radial spread of the robot. The robot according to any one of claims 1 to 3.

5. The application of fluid pressure to operate the actuator causes longitudinal expansion or contraction of the actuator to move the manipulator. The actuator is configured such that the lateral expansion or contraction of the actuator during the operation is directed radially inward, away from the wall of the body lumen. The robot according to claim 4.

6. The frame (12) is positioned to protect the soft actuator (16) from forces exerted by the body cavity. The robot according to any one of claims 1 to 5.

7. The soft actuator is positioned relative to the frame so as to suppress lateral deflection of the frame due to lateral forces. The surgical robot according to any one of claims 1 to 6.

8. A surgical robot deployed in a body cavity inside a human or animal subject, wherein the robot is An expandable frame (12) having a folded state for sending to a target location within the lumen, and an expanded state in which the frame defines an open cavity, A manipulator (14) that can move within the cavity for operating a medical device, To apply a lateral force by applying force between the frame and the manipulator so that the manipulator moves laterally in a radially outward direction within the cavity, a soft actuator fixed to the frame is provided. It has, The soft actuator is positioned relative to the frame so as to suppress the lateral deflection of the frame due to the lateral force. A surgical robot characterized by the following features.

9. Lateral deflection of the frame is suppressed by fixing the soft actuator to the frame and aligning it with the wall of the frame, for example, the soft actuator is held on the surface of the wall, for example, the soft actuator is positioned in the cavity (18) proximal to the manipulator (14). The robot according to any one of claims 1 to 8.

10. The soft actuator (16) is operable to extend and contract in a direction along the surface of the wall in order to apply force to move the manipulator, for example, the wall is linear. The robot according to claim 9.

11. The aforementioned surgical robot, Link mechanism (20), It has, The link mechanism (20) is connected between the manipulator (14) and the soft actuator (16), and is routed via line guide elements (22, 24), The line guide elements (22, 24) are fixed to the frame and configured to guide the control line (15) of the link mechanism so that it can move around the curved portion. The robot according to any one of claims 1 to 10.

12. The link mechanism is fixed to the frame (12) by the actuator (16), and for example, the link mechanism is flexibly fixed by a tether (26). The robot according to claim 11.

13. The link mechanism is, Movable member (28) and At least a line guide element (30) is provided on the movable member (28) and configured to guide the control line (15) of the link mechanism so that it can move around the curved portion, Equipped with, The robot according to claim 8 or 9.

14. The control line (15) of the link mechanism is connected to the manipulator (14) to move the manipulator and is routed through at least one pulley (30) positioned on the movable member. The robot according to claim 13.

15. The control line (15) connected to the manipulator is, for example, fixed to the frame (12) at the vertex of the frame. The robot according to claim 14.

16. The aforementioned framework is The frame comprises a plurality of elongated, expandable pillars (13) that are aligned with each other between adjacent vertices, For example, the pillar (13) is straight. The robot according to any one of claims 1 to 15.

17. The frame has an integral structure formed from two laminated sheets of a flexible material, for example, the laminated sheets are configured to fold to provide the vertices of the frame. The robot according to any one of claims 1 to 16.

18. The aforementioned sheet is A row of openings configured to be positioned along the vertices of the frame between adjacent pillars, Equipped with, The robot according to claim 17, which is dependent on claim 10.

19. At least one of the openings functions to secure the soft actuator to its apex, for example, a clip extending through two of the openings to secure the soft actuator. The robot according to claim 18.

20. The aforementioned sheet is Linear joint areas such as welds, Equipped with, The linear bonding region extends between the openings and borders the unbonded region of the sheet. The non-bonded region forms the pillar when fluid pressure is applied between the sheets. The robot according to claim 18 or 19.

21. The aforementioned framework is A first fluid port is arranged to supply the expanding fluid to the frame, Equipped with, The frame holds a second fluid port for supplying expansion fluid to the soft actuator. The robot according to any one of claims 17 to 20.

22. The aforementioned manipulator is, A shaft rotatably mounted within the cavity, Equipped with, The robot according to any one of claims 1 to 21.

23. The shaft is positioned such that an elongated medical device can be placed through the lumen of the shaft. The robot according to claim 22.

24. The shaft holds an extension that is movable to move forward and backward in the axial direction from the cavity, so that, for example, the shaft and the extension together provide an extendable rigid member. The robot according to claim 23.

25. The frame holds a flexible connecting portion positioned to flexibly support a portion of the elongated medical device at the proximal end of the shaft. The robot according to claim 24.

26. The flexible connecting portion is configured to allow the elongated medical device to move forward and backward. The robot according to claim 25.

27. The shaft holds a device connector configured to removably hold the elongated medical device relative to the shaft at a selected axial position. The robot according to any one of claims 23 to 26.

28. The equipment connecting portion connects the elongated medical device to the shaft such that the forward movement of the elongated medical device results in the extension of the shaft's extension portion. The robot according to claim 27.

29. Both the soft actuator and the frame are layered structures configured to unfold from the folded state in response to expansion. The robot according to any one of claims 1 to 28.

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