WO2023194786A1

WO2023194786A1 - A self-reliant flexible manipulator

Info

Publication number: WO2023194786A1
Application number: PCT/IB2022/055040
Authority: WO
Inventors: Mobin SABOOHI; Alireza MIRBAGHERI; Seyed Farshad ALLAMEH; Saeed Sarkar
Original assignee: Saboohi Mobin; Mirbagheri Alireza; Allameh Seyed Farshad; Saeed Sarkar
Priority date: 2022-04-09
Filing date: 2022-05-29
Publication date: 2023-10-12

Abstract

A self-reliant manipulator includes a continuum robot, a feeding tube coaxially mounted around the continuum robot, an annular body with a central passthrough mounted at an entrance to a body cavity, a stiffening cover, and a stiffness adjustment mechanism. The first end of the stiffening cover is disposed within the feeding tube over an outer surface of the continuum robot. The first end of the stiffening cover is attached to the proximal end of the feeding tube. The stiffening cover extends within the feeding tube and then folds back onto an outer surface of the feeding tube at the distal end of the feeding tube. The second end of the stiffening cover is attached to the annular body. The stiffness adjustment mechanism is configured to regulate a stiffness of a portion of the stiffening cover that may be disposed on the outer surface of the feeding tube.

Description

A SELF-RELIANT FLEXIBLE MANIPULATOR

TECHNICAL FIELD

[0001] The present disclosure generally relates to continuum or snake-like robot systems, and particularly, relates to stiffening mechanisms of continuum or snake-like robot systems.

BACKGROUND

[0002] Continuum robots or manipulators may be highly compliant that may allow continuum robots to traverse tortuous paths safely. In addition, continuum robots may be rigidized in complex shapes, which may allow continuum robots to maintain a desired shape and exert the required force during manipulation. A continuum robot may be stiffened or rigidized by either regulating intrinsic properties of the continuum robot structure, such as second moment of area and elastic properties of the structure or by employing embedded actuators to resist the bending force of the continuum robot structure. Stiffening methods based on utilizing embedded actuators may lead to a relatively larger manipulator and may pose scalability limitations. Furthermore, stiffening methods based on adjusting intrinsic properties of the structure that may require high current/voltage/temperature/force for activation or have a transition time of more than a second are not suitable for medical usage or direct human interaction. For example, stiffening methods based on utilizing magneto-Zelectrorheological fluids and electroactive polymers may require high currents or high voltages for activation. In another example, stiffening methods based on shape memory alloys may require high temperatures or high forces to change their properties.

[0003] A self-reliant manipulator may refer to a manipulator that may be capable of maintaining its shape as it advances in a tortuous path, especially beyond two curves. Here, being self-reliant may refer to a manipulator not being reliant on inner walls of a tortuous path through which a manipulator advances. Being self-reliant may allow for a manipulator to have a deeper access and an increased dexterity. Although intrinsically actuated continuum or snakelike robots may be self-reliant, their scalability limitations may not be of interest. On the other hand, extrinsically actuated manipulators may also be self-reliant by utilizing concentric manipulators. Such self-reliant extrinsically actuated manipulators may be powered by utilizing at least two concentric manipulators that may be extrinsically actuated. Three types of manipulators have been reported: concentric tubes, concentric manipulators with segment locking, and concentric manipulators with longitudinal locking.

[0004] A backbone of concentric tubes may be composed of several (typically two or three) hollow tubes, with smaller radius tubes inserted through larger radius tubes. Each smaller tube may be pushed through the tube immediately adjacent to it to increase the length of the backbone. The tubes may also be rotated to give 2n degrees of freedom for an n-tube backbone. The tubes may be manufactured with a constant curvature, allowing them to be extended and bent in any direction. The concentric tubes group demonstrates remarkable advantages over conventional continuum robots, including greater scalability, no switching time delay associated with element stiffening, and a smaller actual contact area between the manipulator and the path’s wall. However, there are disadvantages, including vibration during force insertion, lower stiffness than comparable continuum robots, a more significant number of actuators required to position and orient the robot than a continuum robot, stiffness variation along the body length, stiffness control disability at any length of insertion.

[0005] Concentric manipulators equipped with segment locking may be arranged as an inner continuum or snake-like robot with segment locking and as an outer one. By tightening the cable with the motor, the inner manipulator may become rigid for advancement, whereas the outer manipulator may be made flexible or limp. After advancing the outer manipulator, it may be stiffened to maintain the path’s shape. The inner robot may then be made flexible to pass through the outer robot, and the preceding steps may be repeated. This group may have stiffness controllability and may provide a broader stiffness range than the concentric tubes group. However, there are disadvantages, including configuration distortion after passing two curves, a delay in stiffness switching between manipulators, less stiffness than manipulators equipped with longitudinal locking, and a larger actual contact area between the manipulator and the path’s wall rather than a concentric tube group.

[0006] A concentric manipulator with longitudinal locking may include an inner rigidizing manipulator positioned within the outer rigidizing manipulator so that the inner manipulator may extend beyond the outer manipulator. The distal end of the inner manipulator may be curved and rigid. The outer manipulator may be advanced over the rigidized inner manipulator when necessary. The outer manipulator may then be rigidized. The following curves may be formed by repeating the previous steps. Each manipulator may be held in place by a longitudinal locking layer. The layer may be connected to a vacuum pump through the inlet, resulting in a rigid configuration when vacuum or pressure is applied and a flexible configuration when neither is applied. A concentric manipulator with longitudinal locking indicates higher stiffness than other groups. Additionally, this group of self-reliant manipulators may traverse more than two curves without introducing configuration distortion. However, the disadvantages include a longer time delay for stiffness switching between manipulators and a larger actual contact area between the manipulator and the path’s wall than the concentric tube group.

[0010] There is a need for self-reliant manipulators that may be able to control their stiffness in any configuration without distorting the manipulator. There is further a need for combining inner and outer manipulators to overcome the stiffness switching time delay. There is still a need for self-reliant manipulators that may avoid or minimize contact with the path’s wall, reducing friction between the manipulator and the path.

SUMMARY

[0011] This summary is intended to provide an overview of the subject matter of the present disclosure and is not intended to identify essential elements or key elements of the subject matter, nor is it intended to be used to determine the scope of the claimed implementations. The proper scope of the present disclosure may be ascertained from the claims set forth below in view of the detailed description and the drawings.

[0012] According to one or more exemplary embodiments, the present disclosure is directed to an exemplary self-reliant manipulator. An exemplary self-reliant manipulator may include a continuum robot and a feeding tube that may be coaxially mounted around an exemplary continuum robot. An exemplary feeding tube may extend between a proximal end of an exemplary feeding tube and a distal end of a feeding tube. An exemplary feeding tube may be moveable relative to an exemplary continuum robot along a main axis of an exemplary continuum robot. An exemplary self-reliant manipulator may further include an annular body with a central passthrough that may be configured to be mounted at an entrance to a body cavity. An exemplary annular body may be configured to allow passage of an exemplary continuum robot and an exemplary feeding tube through an exemplary central passthrough of an exemplary annular body into an exemplary body cavity.

[0013] An exemplary self-reliant manipulator may further include a stiffening cover that may extend between a first end of an exemplary stiffening cover and a second end of an exemplary stiffening cover. An exemplary first end of an exemplary stiffening cover may be disposed between an inner surface of an exemplary feeding tube and an outer surface of an exemplary continuum robot. An exemplary first end of an exemplary stiffening cover may be attached to an exemplary proximal end of an exemplary feeding tube. An exemplary stiffening cover may extend within an exemplary feeding tube between an exemplary proximal end and an exemplary distal end of an exemplary feeding tube. An exemplary stiffening cover may be folded back onto an outer surface of an exemplary feeding tube at an exemplary distal end of an exemplary feeding tube. An exemplary stiffening cover may further be extended over an exemplary outer surface of an exemplary feeding tube between an exemplary distal end of an exemplary feeding tube and an exemplary annular body. An exemplary second end of an exemplary stiffening cover may be attached to an exemplary annular body. An exemplary stiffening cover may further be pulled out from within an exemplary feeding tube and may be deployed onto an exemplary outer surface of an exemplary feeding tube in response to an exemplary feeding tube moving along an exemplary continuum robot relative to an exemplary annular body.

[0014] An exemplary self-reliant manipulator may further include a stiffness adjustment mechanism that may be coupled to an exemplary stiffening cover. An exemplary stiffness adjustment mechanism may be configured to regulate a stiffness of a portion of an exemplary stiffening cover that may be disposed on the outer surface of an exemplary feeding tube.

[0015] An exemplary self-reliant manipulator may further include a sealing mechanism that may be mounted on an exemplary distal end of an exemplary feeding tube. An exemplary sealing mechanism may include a ball bearing that may include an annular bearing body mounted around the distal end of the feeding tube and a plurality of balls annularly arranged inside the annular bearing body, and a pair of retaining rings mounted around an exemplary distal end of an exemplary feeding tube at both lateral sides of an exemplary ball bearing. Exemplary pair of retaining rings may be coaxial with an exemplary ball bearing.

[0016] An exemplary stiffening cover may extend out of an exemplary distal end of an exemplary feeding tube and may fold back around a first retaining ring of exemplary pair of retaining rings onto an exemplary outer surface of an exemplary feeding tube. An exemplary stiffening cover may further extend through an exemplary bearing unit passing between an exemplary plurality of balls and an exemplary outer surface of an exemplary feeding tube and over a second retaining ring of an exemplary pair of retaining rings. [0017] An exemplary self-reliant manipulator may further include a cover retraction mechanism. An exemplary cover retraction mechanism may include an annular cover housing that may be attached to an exemplary proximal end of an exemplary feeding tube. An exemplary annular cover housing may include a central hole, where an exemplary central hole may be configured to allow for passage of an exemplary continuum robot. An exemplary annular cover housing may be moveable relative to an exemplary continuum robot along an exemplary main axis of an exemplary continuum robot. An exemplary plurality of spring- loaded tendons may be configured to connect an exemplary annular housing to an exemplary first end of an exemplary stiffening cover.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The novel features which are believed to be characteristic of the present disclosure, as to its structure, organization, use and method of operation, together with further objectives and advantages thereof, will be better understood from the following drawings in which a presently preferred embodiment of the present disclosure will now be illustrated by way of example. It is expressly understood, however, that the drawings are for illustration and description only and are not intended as a definition of the limits of the present disclosure. Embodiments of the present disclosure will now be described by way of example in association with the accompanying drawings in which:

[0019] FIG. 1 illustrates a schematic side-view of a self-reliant manipulator, consistent with one or more exemplary embodiments of the present disclosure;

[0020] FIG. 2 illustrates a sectional schematic view of a stiffening cover pulled over a feeding tube, consistent with one or more exemplary embodiments of the present disclosure;

[0021] FIG. 3 illustrates a sectional side-view of a cover retraction mechanism, consistent with one or more exemplary embodiments of the present disclosure;

[0022] FIG. 4 illustrates a stiffness adjustment mechanism functioning based on exerting negative pressure on a stiffening cover, consistent with one or more exemplary embodiments of the present disclosure;

[0023] FIG. 5 illustrates a stiffness adjustment mechanism functioning based on exerting positive pressure on a stiffening cover, consistent with one or more exemplary embodiments of the present disclosure; [0024] FIG. 6 illustrates a stiffness adjustment mechanism functioning based on exerting a distributed force on a stiffening cover, consistent with one or more exemplary embodiments of the present disclosure;

[0025] FIG. 7 illustrates a sectional side-view of a tip feeding mechanism, consistent with one or more exemplary embodiments of the present disclosure;

[0026] FIG. 8 illustrates a sectional side-view of a tip feeding mechanism, consistent with one or more exemplary embodiments of the present disclosure; and

[0027] FIGs. 9A-9D illustrate different manipulation stages of a self-reliant manipulator, consistent with one or more exemplary embodiments of the present disclosure.

DETAILED DESCRIPTION

[0028] The novel features which are believed to be characteristic of the present disclosure, as to its structure, organization, use and method of operation, together with further objectives and advantages thereof, will be better understood from the following discussion.

[0029] The present disclosure is directed to exemplary embodiments of a self-reliant manipulator that may be utilized in endoscopic or colonoscopy applications, as well as any other similar applications. An exemplary self-reliant robot may be maneuvered in a tortuous path without being dependent on an inner wall of an exemplary tortuous path. To this end, an exemplary self-reliant manipulator may include a continuum robot that may be maneuverable within an exemplary tortuous path and a stiffening mechanism that may be coupled to an exemplary continuum robot to maintain curvilinear shaped taken by an exemplary continuum robot as well as providing a rigid path for an exemplary continuum robot to rely on.

[0030] An exemplary self-reliant manipulator may include a feeding tube that may be coaxially mounted around a continuum robot. An exemplary feeding tube may be moveable along a main axis of an exemplary continuum robot relative to an exemplary continuum robot. An exemplary self-reliant manipulator may further include an annular body that may be positioned at an entrance of a tortuous path. An exemplary annular robot and an exemplary feeding tube associated with an exemplary continuum robot may enter an exemplary tortuous path through a central passthrough provided in an exemplary annular body.

[0031] An exemplary stiffening cover may be coupled between an exemplary feeding tube and an exemplary annular body. To this end, a first end of an exemplary stiffening cover may be disposed within an exemplary feeding tube between an inner surface of an exemplary feeding tube and an outer surface of an exemplary continuum robot. An exemplary first end of an exemplary stiffening cover may be attached to a proximal end of an exemplary feeding tube. An exemplary stiffening cover may extend within an exemplary feeding tube from an exemplary proximal end of an exemplary feeding tube to a distal end of an exemplary feeding tube. An exemplary stiffening cover may be folded back onto an outer surface of an exemplary feeding tube. An exemplary stiffening cover may then be extended from an exemplary distal end of an exemplary feeding tube over an exemplary outer surface of an exemplary feeding tube to an annular body mounted around an exemplary feeding tube. An exemplary second end of an exemplary stiffening cover may be attached to an exemplary annular body.

[0032] An exemplary self-reliant manipulator may further include a stiffness adjustment mechanism that may be coupled to an exemplary stiffening cover. An exemplary stiffness adjustment mechanism may be configured to regulate a stiffness of a portion of an exemplary stiffening cover that may be disposed on an exemplary outer surface of an exemplary feeding tube.

[0033] An exemplary continuum robot may pass through an exemplary annular body and may be inserted into a body cavity. Then an exemplary continuum robot may be manipulated into a first curve. An exemplary stiffening cover that may be attached to an exemplary stiffness adjustment mechanism may cover a portion of outer surface of an exemplary continuum robot within body cavity. An exemplary stiffness adjustment mechanism may urge a portion of an exemplary stiffening cover that may be placed over and around an exemplary feeding tube to be stiffened and rigid. At this stage, it is time for covering the entire outer surface of a portion of an exemplary continuum robot that has been inserted into the body cavity and that has taken the first curved path. To this end, an exemplary feeding tube may be pushed forward along a main axis of an exemplary continuum robot.

[0034] When an exemplary feeding tube is pushed forward relative and over an exemplary continuum robot, an exemplary stiffening cover may be further pulled out of an exemplary feeding tube and may cover the entire outer surface of the portion of an exemplary continuum robot that has been inserted into the body cavity. During the forward motion of an exemplary feeding tube over an exemplary continuum robot, an exemplary stiffness adjustment mechanism may keep a portion of an exemplary stiffening cover that may be placed over and around an exemplary feeding tube stiff and rigid while the rest of an exemplary stiffening cover disposed within an exemplary feeding tube may be flexible. At this stage, an exemplary continuum robot may be pushed further into an exemplary body cavity.

[0035] An exemplary continuum robot may further be manipulated into an exemplary body cavity and may take another curve within an exemplary body cavity. When an exemplary continuum robot moves forward into an exemplary body cavity, a portion of an exemplary continuum robot may extend out of an exemplary feeding tube that needs to be covered by an exemplary stiffening cover. To this end, an exemplary feeding tube may further be pushed forward over and relative to an exemplary continuum robot. Here, an exemplary stiffening cover may further be pulled out of an exemplary feeding tube and may cover the entire outer surface of the portion of an exemplary continuum robot that has been inserted into an exemplary body cavity. During the forward motion of an exemplary feeding tube over an exemplary continuum robot, an exemplary stiffness adjustment mechanism may keep a portion of an exemplary stiffening cover placed over and around feeding tube stiff and rigid while the rest of an exemplary stiffening cover disposed within an exemplary feeding tube may be flexible. At this stage, an exemplary continuum robot has taken a full S -shaped curve and an exemplary stiffening cover has covered an outer surface of an exemplary continuum robot. In An exemplary stiffness adjustment mechanism may keep the portion of an exemplary stiffening cover placed over and around an exemplary feeding tube stiff and rigid so that the S -curved shape may be preserved.

[0036] When an exemplary self-reliant manipulator is to be pulled out of an exemplary body cavity, an exemplary cover retraction mechanism may be configured to retract an exemplary stiffening cover back into an exemplary feeding tube as feeding tube is being pulled out. An exemplary portion of an exemplary stiffening cover that may be placed over and around an exemplary feeding tube within the body cavity may not have any slipping motion relative to an inner wall of the body cavity due to the fact that an exemplary stiffening cover is being deployed onto an exemplary feeding tube from a tip of an exemplary feeding tube. Consequently, not only an exemplary self-reliant manipulator may not rely on inner walls of the body cavity to maneuver through the body cavity, but an exemplary reliant manipulator may further not have any relative slippage on an inner wall of the body cavity.

[0037] FIG. 1 illustrates a schematic side-view of a self-reliant manipulator 100, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, self-reliant manipulator 100 may include a continuum robot 102 and a stiffening cover 104 that may be deployed on continuum robot 102 and may further be configured to allow for adjusting a stiffness of self-reliant manipulator 100. In an exemplary embodiment, self-reliant manipulator 100 may further include a tip feeding mechanism that may include a feeding tube 106, a sealing mechanism 108 that may be mounted on a distal end 110 of feeding tube 106, and a cover retraction mechanism 112 that may be attached to a proximal end 114 of feeding tube 106 and may be configured to couple stiffening cover 104 to feeding tube 106. [0038] In an exemplary embodiment, a first end 116a of stiffening cover 104 may be disposed within feeding tube 106 and may be attached to cover retraction mechanism 112 at proximal end 114 of feeding tube 106. In an exemplary embodiment, stiffening cover 104 may extend within and along feeding tube 106 from proximal end 114 of feeding tube 106 to distal end 110 of feeding tube 106, where sealing mechanism 108 may be configured to allow for stiffening cover 104 to be pulled back over an outer surface 118 of feeding tube 106. In an exemplary embodiment, after passing through sealing mechanism 108, stiffening cover 104 may be extendable over and along feeding tube 106 from distal end 110 of feeding tube 106 to a stiffness adjustment mechanism 120 that may be mounted at an entry zone 122 through which feeding tube 106 and continuum robot 102 may enter a body cavity. In an exemplary embodiment, entry zone 122 may include an annular body 126 that may be placed at an entrance or access point to a body cavity. For example, annular body 126 may function as a mouthpiece in endoscopy applications, or an annular piece placed at the entrance of a patient's clone in colonoscopy applications.

[0039] In an exemplary embodiment, a second end 1166 of stiffening cover 104 may be attached to annular body 126. Consequently, a portion of stiffening cover 104 may be placed over outer surface 118 of feeding tube 106 and the rest of stiffening cover 104 may be disposed within feeding tube 106. In an exemplary embodiment, feeding tube 106 may be a flexible tube that may be coaxially moveable along continuum robot 102. In an exemplary embodiment, moving feeding tube 106 forward along a main axis 124 of continuum robot 102 may urge stiffening cover 104 to be further pulled out of feeding tube 106 and be deployed over feeding tube 106.

[0040] In an exemplary embodiment, stiffness adjustment mechanism 120 may be mounted in entry zone 122. In an exemplary embodiment, stiffness adjustment mechanism 120 may be coupled to stiffening cover 104 and feeding tube 106 and may be configured to adjust the stiffness of stiffening cover 104, as will be discussed. [0041] In an exemplary embodiment, continuum robot 102 may include a manipulator with infinite degrees of freedom that may allow for the shape of continuum robot 102 to be adjusted and modified along a length of continuum robot 102. Such adjustability and configurability of the shape of continuum robot 102 may allow accessing confined spaces and complex environments, such as body cavities. In an exemplary embodiment, continuum robot 102 may include a snake -like robot with a leader and follower structure, where only an exemplary leader part of continuum robot 102 may be actively driven and an exemplary follower part of continuum robot 102 may passively follow an exemplary leader part and may conform to a curvilinear path taken by an exemplary leader part. In an exemplary embodiment, an exemplary leader part of continuum robot 102 may include a tip of continuum robot 102. In an exemplary embodiment, continuum robot 102 may have an extrinsic actuation mechanism, where actuation forces from an external actuator may be transmitted to continuum robot 102 by utilizing mechanical transmission mechanisms, such as tendon-based mechanisms. For example, a plurality of tendons may be embedded along continuum robot 102 and may be configured to transfer the movements of at least one external actuator to continuum robot 102. In an exemplary embodiment, continuum robot 102 may be configured to be driven along curved paths. For simplicity, details of continuum robot 102, actuators, and end-effectors of continuum robot 102 are not further discussed here.

[0042] In an exemplary embodiment, stiffening cover 104 may include a plurality of longitudinal elements, such as longitudinal thin plates interconnected to each other similar to fish scales. In an exemplary embodiment, responsive to be subjected to a certain amount of pressure, the friction between the aforementioned scale-like longitudinal plates may increase and the aforementioned scale-like plates may be interlocked. Consequently, the stiffness of stiffening cover 104 may be increased by exerting positive or negative pressure on stiffening cover 104.

[0043] FIG. 2 illustrates a sectional schematic view of a stiffening cover 200 pulled over a feeding tube 202, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, stiffening cover 200 may be similar to stiffening cover 104 and feeding tube 202 may be similar to feeding tube 106. In an exemplary embodiment, stiffening cover 200 may include a first layer 204 that may be made of longitudinal elements 206 that may be arranged like fish scales and a second layer 208 that may be made of an elastic material. In an exemplary embodiment, first layer 204 may be disposed between second layer 208 and feeding tube 202. In an exemplary embodiment, such arrangement of first layer 204 and second layer 208 may allow for achieving a variable stiffness for stiffening cover 200 by utilizing a layer jamming method. In an exemplary layer jamming method, the friction between longitudinal elements 206 may be controlled by applying pressure onto first layer 204. For example, a negative pressure may be applied between an inner surface of second layer 208 and an outer surface of first layer 204 to tighten second layer 208 around first layer 204, thereby exerting pressure onto first layer 204. In response to the applied pressure, the friction between longitudinal elements 206 may increase and layer jamming may occur.

[0044] FIG. 3 illustrates a sectional side-view of a cover retraction mechanism 300, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, cover retraction mechanism 300 may be structurally similar to cover retraction mechanism 112. In an exemplary embodiment, cover retraction mechanism 300 may include a cover housing 302, a plurality of tendons 304 that may be disposed within cover housing 302, and a plurality of corresponding spiral springs 306 that may be attached to respective tendons 304. In an exemplary embodiment, plurality of tendons 304 may further be attached to a first end 308 of a stiffening cover 310 that may be structurally similar to stiffening cover 104. In an exemplary embodiment, spiral springs 306 may be configured to exert a constant retraction force on stiffening cover 310. In an exemplary embodiment, cover housing 302 may include a central pass through 312 that may be configured to allow for the passage of a continuum robot 314 that may be structurally similar to continuum robot 102. In an exemplary embodiment, a proximal end 315 of a feeding tube 316 similar to feeding tube 106 may be attached to cover retraction mechanism 300. In an exemplary embodiment, feeding tube 316 may be moveable with cover retraction mechanism 300 along continuum robot 314.

[0045] In an exemplary embodiment, first end 116a of stiffening cover 104 being disposed within feeding tube 106 and being attached to cover retraction mechanism 112 may refer to attaching first end 116a of stiffening cover 104 to a plurality of spring -loaded tendons that may be structurally similar to plurality of tendons 304 attached to respective spiral springs 306.

[0046] FIG. 4 illustrates a stiffness adjustment mechanism 400 functioning based on exerting negative pressure on a stiffening cover 402, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, stiffness adjustment mechanism 400 may be structurally and functionally similar to stiffness adjustment mechanism 120 of self-reliant manipulator 100. In an exemplary embodiment, stiffness adjustment mechanism 400 may include an annular body 401 that may be positioned against an entrance to a cavity through which self-reliant manipulator 100 is to be inserted. In an exemplary embodiment, annular body 401 may be similar to annular body 126 within entry zone 122. In an exemplary embodiment, annular body 401 may be configured to allow passage of a continuum robot 404 similar to continuum robot 102 and a feeding tube 406 similar to feeding tube 106 through annular body 401. In an exemplary embodiment, stiffness adjustment mechanism 400 may further include an annular locking member 408 that may be associated with annular body 401 and may be configured to prevent movement of a feeding tube 406 through annular body 401 on demand.

[0047] In an exemplary embodiment, a first end 410 of a stiffening cover 402 similar to first end 308 of stiffening cover 310 may be attached to tendons 414 similar to tendons 304 and a second end 416 of stiffening cover 402 may be attached to annular body 401. In other words, in an exemplary embodiment, second end 1166 of stiffening cover 104 being attached to stiffness adjustment mechanism 120 may refer to second end 416 of stiffening cover 402 being attached to annular body 401 of stiffness adjustment mechanism 400. In an exemplary embodiment, stiffness adjustment mechanism 400 may be fixed at an entry zone to a body cavity during the operation, while continuum robot 404 and feeding tube 406 may be inserted into or pulled back out from an exemplary body cavity.

[0048] In an exemplary embodiment, annular body 401 may further include an annular aperture 418 that may be connected in fluid communication with stiffening cover 402 and may be configured to provide a fluid communication between stiffening cover 402 and a vacuum pump. In an exemplary embodiment, as illustrated in inset 420, stiffening cover 402 may be structurally similar to stiffening cover 200 and may include an inner layer 422 made of a plurality of longitudinal elements similar to plurality of longitudinal elements 206. In an exemplary embodiment, stiffening cover 402 may further include an elastic outer layer 424 disposed around inner layer 422. In an exemplary embodiment, annular aperture 418 may be connected in fluid communication with an interlayer space 426 between inner layer 422 and elastic outer layer 424. In an exemplary embodiment, a vacuum pump (not illustrated) may be connected to annular aperture 418 and may apply negative pressure on interlayer space 426 by evacuating the air within interlayer space 426. In an exemplary embodiment, in response to a vacuum pump exerting negative pressure on interlayer space 426 by discharging the air within interlayer space 426, elastic outer layer 424 may be tighten around inner layer 422. As was discussed, in response to elastic outer layer 424 being tightened around inner layer 422 the friction between the plurality of longitudinal elements of inner layer 422 may increase and consequently stiffening cover 402 may be rigidized. In other words, the stiffness of stiffening cover 402 may be regulated by adjusting the amount of negative pressure applied by utilizing a vacuum pump on stiffening cover 402.

[0049] FIG. 5 illustrates a stiffness adjustment mechanism 500 functioning based on exerting positive pressure on a stiffening cover 502, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, stiffness adjustment mechanism 500 may be functionally similar to stiffness adjustment mechanism 120 of self- reliant manipulator 100 in that stiffness adjustment mechanism 500 may also be configured to regulate the stiffness of stiffening cover 502. In an exemplary embodiment, stiffness adjustment mechanism 500 may include an annular body 510 that may be positioned against an entrance to a cavity through which self-reliant manipulator 100 is to be inserted. In an exemplary embodiment, annular body 510 may be similar to annular body 126 within entry zone 122. In an exemplary embodiment, annular body 510 may be configured to allow passage of a continuum robot 504 similar to continuum robot 102 and a feeding tube 506 similar to feeding tube 106 through annular body 510.

[0050] In an exemplary embodiment, a first end 508 of a stiffening cover 502 similar to first end 308 of stiffening cover 310 may be attached to tendons 512 similar to tendons 304 and a second end 514 of stiffening cover 502 may be attached to annular body 510. In other words, in an exemplary embodiment, second end 1166 of stiffening cover 104 being attached to stiffness adjustment mechanism 120 may refer to second end 514 of stiffening cover 502 being attached to annular body 510 of stiffness adjustment mechanism 500. In an exemplary embodiment, stiffness adjustment mechanism 500 may be fixed at an entry zone to a body cavity during the operation, while continuum robot 504 and a feeding tube 506 may be inserted into or pulled back out from an exemplary body cavity.

[0051] In an exemplary embodiment, annular body 510 may further include an annular aperture 516 that may be connected in fluid communication with a space 518 between stiffening cover 502 and feeding tube 506. In an exemplary embodiment, annular aperture 516 may further be connected in fluid communication with an air compressor (not illustrated). In other words, annular aperture 516 may be configured to provide a fluid communication between space 518 and an air compressor, such that pressurized air provided by the air compressor may be compressed into space 518. In an exemplary embodiment, in response to compressed air injected into space 518 between stiffening cover 502 and feeding tube 506, a positive pressure may be exerted onto stiffening cover 502 that may lead to layer jamming occurring within stiffening cover 502 which in turn increases the stiffness of stiffening cover 502.

[0052] FIG. 6 illustrates a stiffness adjustment mechanism 600 functioning based on exerting a distributed force on a stiffening cover 602, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, stiffness adjustment mechanism 600 may be functionally similar to stiffness adjustment mechanism 120 of self- reliant manipulator 100 in that stiffness adjustment mechanism 600 may also be configured to regulate the stiffness of stiffening cover 602. In an exemplary embodiment, stiffness adjustment mechanism 600 may include an annular body 610 that may be positioned against an entrance to a cavity through which self-reliant manipulator 100 is to be inserted. In an exemplary embodiment, annular body 610 may be similar to annular body 126 within entry zone 122. In an exemplary embodiment, annular body 610 may be configured to allow passage of a continuum robot 604 similar to continuum robot 102 and a feeding tube 606 similar to feeding tube 106 through annular body 610.

[0053] In an exemplary embodiment, a first end 608 of a stiffening cover 602 similar to first end 308 of stiffening cover 310 may be attached to tendons 612 similar to tendons 304 and a second end 614 of stiffening cover 602 may be attached to annular body 610. In other words, in an exemplary embodiment, second end 1166 of stiffening cover 104 being attached to annular body 126 may refer to second end 614 of stiffening cover 602 being attached to annular body 610 of stiffness adjustment mechanism 600. In an exemplary embodiment, stiffness adjustment mechanism 600 may be fixed at an entry zone to a body cavity during the operation, while continuum robot 604 and a feeding tube 606 may be inserted into or pulled back out from an exemplary body cavity.

[0054] In an exemplary embodiment, annular body 610 may further include an annular aperture 616 that may be connected to a space 618 between stiffening cover 602 and feeding tube 606. In an exemplary embodiment, annular aperture 616 may be configured to allow for a plurality of inflatable pipes/in verse inflatable pipes 620 to be inserted into space 618. In an exemplary embodiment, in response to insertion of inflatable pipes/inverse inflatable pipes 620 into space 618 between stiffening cover 602 and feeding tube 606, a distributed force may be exerted onto stiffening cover 602 that may lead to layer jamming occurring within stiffening layer 618 which in turn increases the stiffness of stiffening cover 602.

[0055] FIG. 7 illustrates a sectional side-view of a tip feeding mechanism 700, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, tip feeding mechanism 700 may include a feeding tube 702 that may be structurally and functionally similar to feeding tubes (106, 202, 316, 406, 506, and 606). In an exemplary embodiment, tip feeding mechanism 700 may further include a sealing mechanism 704 that may be structurally and functionally similar to sealing mechanism 108. In an exemplary embodiment, sealing mechanism 704 may be mounted to a distal end 706 of feeding tube 702. [0056] In an exemplary embodiment, sealing mechanism 704 may include a ball bearing 708 and retaining rings 710. In an exemplary embodiment, ball bearing 708 may include an annular bearing body 712 that may be mounted around distal end 706 of feeding tube 702 and a plurality of balls 714 that may be annularly arranged inside annular bearing body 712. In an exemplary embodiment, plurality of balls 714 may be placed over a stiffening cover 716 and may press stiffening cover 716 to distal end 706 of feeding tube 702. In an exemplary embodiment, retaining rings 710 may be mounted around distal end 706 of feeding tube 702 such that plurality of balls 714 may be positioned between retaining rings 710. In an exemplary embodiment, such placement of retaining rings 710 and plurality of balls 714 may allow for retaining rings 710 to prevent any unwanted translational movements of plurality of balls 714. [0057] In an exemplary embodiment, stiffening cover 716 may be pulled out and over feeding tube 702. To this end, stiffening cover 716 may be folded back onto feeding tube 702 by utilizing a first retaining ring 710a of retaining rings 710 as an anchor. In an exemplary embodiment, stiffening cover 716 may be disposed between plurality of balls 714 and feeding tube 702 and may slip over retaining rings 710 and under plurality of balls 714.

[0058] In an exemplary embodiment, plurality of balls 714 of ball bearing 708 may separate the confined space between stiffening cover 716 and feeding tube 702 into an inner confined space 718 and an outer confined space 720. In an exemplary embodiment, inner confined space 718 may refer to a space confined between stiffening cover 716 and an inner surface of feeding tube 702. In an exemplary embodiment, outer confined space 720 may refer to a space confined between stiffening cover 716 and an outer surface of feeding tube 702. In an exemplary embodiment, outer confined space 720 may be associated with a stiffness adjustment mechanism that may be structurally similar to stiffness adjustment mechanism 500. [0059] Specifically, a stiffness adjustment mechanism similar to stiffness adjustment mechanism 500 that may utilize exerting positive pressure to regulate the stiffness of a stiffening cover similar to stiffening cover 716 may be connected in fluid communication to outer confined space 720. In an exemplary embodiment, pressurized air may be injected into outer confined space 720 and may cause an increase in the stiffness of stiffening cover 716 as was discussed before. Here, plurality of balls 714 of ball bearing 708 provide an air-tight seal between outer confined space 720 and inner confined space 718, such that compressed air may nit enter inner confined space 718. Such air-tight seal between outer confined space 720 and inner confined space 718 may allow for increasing the stiffness of a portion of stiffening cover 716 that is pulled over an outer surface of feeding tube 702, while the rest of stiffening cover 716 located within feeding tube 702 may not be stiffened. Furthermore, due to the rolling nature of plurality of balls 714 of ball bearing 708, stiffening cover 716 may easily slip under plurality of balls 714 and yet be tightly pressed against an outer surface of distal end 706 of feeding tube 702. For example, in response to feeding tube 702 being moved along a main axis of continuum robot, since the outer portion of stiffening cover 716 may be fixed to an annular body through which feeding tube 702 may move, stiffening cover 716 may be pulled out of feeding tube 702 and may slip between plurality of balls 714 and retaining rings 710.

[0060] In an exemplary embodiment, stiffening cover 716 may be structurally similar to stiffening cover 200 and may include a first layer made of longitudinal elements similar to first layer 204 and an elastic outer layer similar to second layer 208. Here, plurality of balls 714 of ball bearing 708 may separate the confined space between the elastic outer layer and inner layer into a first confined space and a second confined space. In an exemplary embodiment, first confined space may refer to the confined space between the first layer and the elastic outer layer of a first portion of stiffening cover which may be located on an outer surface of feeding tube. In an exemplary embodiment, second confined space may refer to the confined space between the first layer and the elastic outer layer of a second portion of stiffening cover which may be located within feeding tube. This way, a stiffness adjustment mechanism similar to stiffness adjustment mechanism 400 that may utilize exerting negative pressure to regulate the stiffness of a stiffening cover similar to stiffening cover 716 may only be connected in fluid communication to the first confined space.

[0061] Based on what was discussed in the preceding paragraphs, in an exemplary embodiment, a sealing mechanism similar to sealing mechanism 704 may be configured to first provide an anchor around which a stiffening cover similar to stiffening cover 716 may be folded from within feeding tube 702 back onto an outer surface of feeding tube 702, and then sealing mechanism 704 may further be configured to separate or seal an outer portion of stiffening cover 716 from an inner portion of stiffening cover 716 to allow for a stiffness adjustment mechanism to only adjust the stiffness of a portion of stiffening cover 716 that is pulled over feeding tube 702.

[0062] FIG. 8 illustrates a sectional side-view of a tip feeding mechanism 800, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, tip feeding mechanism 800 may include a feeding cuff 802 that may be mounted on a distal end 804 of a continuum robot 806 and maybe moveable with continuum robot 806. In an exemplary embodiment, feeding cuff 802 may include an annular housing 812 for a plurality of rolling elements 810 that may be disposed in annular housing 812. In an exemplary embodiment, feeding cuff 802 may be attached to distal end 804 of continuum robot 806 by utilizing a retaining ring 813 fastened around distal end 804 of continuum robot 806. In an exemplary embodiment, stiffening cover 814 may be unrolled from around rolling elements 810 as continuum robot 806 moves forward. Here, stiffening cover 814 may be structurally similar to stiffening cover 200 and a stiffness adjustment mechanism based on negative pressure such as stiffness adjustment mechanism 400 may be coupled to stiffening cover 814 to regulate stiffness of stiffening cover 814.

[0063] FIGs. 9A-9D illustrate different manipulation stages of a self-reliant manipulator 900, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, self-reliant manipulator 900 may be structurally similar to self-reliant manipulator 100. In an exemplary embodiment, self-reliant manipulator 900 may include a continuum robot 902 similar to continuum robot 102, a stiffening cover 904 similar to stiffening cover 104, a feeding tube 906 similar to feeding tube 106, and a stiffness adjustment mechanism 910 similar to stiffness adjustment mechanism 120. In an exemplary embodiment, feeding tube 906 may be coupled to stiffening cover 904 by utilizing a cover retraction mechanism 908 similar to cover retraction mechanism 112 and a sealing mechanism 912 similar to sealing mechanism 108. In an exemplary embodiment, stiffness adjustment mechanism 120 may further include an annular body 914 similar to annular body 126 that may be fitted at an inlet zone of a body cavity or any other tortuous path that self-reliant manipulator 900 is to be inserted into. [0064] Referring to FIG. 9A, continuum robot 902 may pass through annular body 914 and may be inserted into a body cavity. Then continuum robot 902 may be manipulated into a first curve. In an exemplary embodiment, stiffening cover 904 that may be attached to stiffness adjustment mechanism 910 may cover a portion of outer surface of continuum robot 902 within body cavity to the right of annular body 914. In an exemplary embodiment, stiffness adjustment mechanism 910 may urge a portion of stiffening cover 904 placed over and around feeding tube 906 to be stiffened and rigid. At this stage, it is time for covering the entire outer surface of a portion of continuum robot 902 that has been inserted into the body cavity and that has taken the first curved path. To this end, feeding tube 906 may be pushed forward along a main axis of continuum robot 902 in a direction shown by arrow 916.

[0065] Referring to FIG. 9B, feeding tube 906 has been pushed forward in the direction shown by arrow 916 and stiffening cover 904 may be further pulled out of feeding tube 906 and may cover the entire outer surface of the portion of continuum robot 902 that has been inserted into the body cavity. In an exemplary embodiment, during the forward motion of feeding tube 906 over continuum robot 902, stiffness adjustment mechanism 910 may keep a portion of stiffening cover 904 placed over and around feeding tube 906 stiff and rigid while the rest of stiffening cover 904 disposed within feeding tube 906 may be flexible thanks to sealing mechanism 912 as was discussed before. At this stage, it is time for pushing continuum robot 902 further into the body cavity.

[0066] Referring to FIG. 9C, continuum robot 902 may further be manipulated into the body cavity in a direction shown by arrow 918 and may take another curve within the body cavity. In an exemplary embodiment, when continuum robot 902 moves forward into the body cavity, a portion of continuum robot may extend out of feeding tube 906 that needs to be covered by stiffening cover 904. To this end, feeding tube 906 may be pushed forward in a direction shown by arrow 920.

[0067] Referring to FIG. 9D, feeding tube 906 has been pushed forward in the direction shown by arrow 920 and stiffening cover 904 may be further pulled out of feeding tube 906 and may cover the entire outer surface of the portion of continuum robot 902 that has been inserted into the body cavity. In an exemplary embodiment, during the forward motion of feeding tube 906 over continuum robot 902, stiffness adjustment mechanism 910 may keep a portion of stiffening cover 904 placed over and around feeding tube 906 stiff and rigid while the rest of stiffening cover 904 disposed within feeding tube 906 may be flexible thanks to sealing mechanism 912 as was discussed before. At this stage, continuum robot 902 has taken a full S- shaped curve and stiffening cover 904 has covered an outer surface of continuum robot 902. In an exemplary embodiment, stiffness adjustment mechanism 910 may keep the portion of stiffening cover 904 placed over and around feeding tube 906 stiff and rigid so that the S- curved shape may be preserved.

[0068] In an exemplary embodiment, when self-reliant manipulator 900 is to be pulled out of a body cavity, cover retraction mechanism 908 may be configured to retract stiffening cover 904 back into feeding tube 906 as feeding tube is being pulled out.

[0069] In an exemplary embodiment, the portion of stiffening cover 904 that may be placed over and around feeding tube 906 within the body cavity may not have any slipping motion relative to an inner wall of the body cavity due to the fact that stiffening cover 904 is being deployed onto feeding tube 906 from a tip of feeding tube 906. Consequently, not only self- reliant manipulator 900 may not rely on inner walls of the body cavity to maneuver through the body cavity, but reliant manipulator 900 may further not have any relative slippage on an inner wall of the body cavity.

[0070] The embodiments have been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.

[0071] The foregoing description of the specific embodiments will so fully reveal the general nature of the disclosure that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present disclosure. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance.

[0072] The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments but should be defined only in accordance with the following claims and their equivalents. [0073] Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not to the exclusion of any other integer or step or group of integers or steps. [0074] Moreover, the word "substantially" when used with an adjective or adverb is intended to enhance the scope of the particular characteristic, e.g., substantially planar is intended to mean planar, nearly planar and/or exhibiting characteristics associated with a planar element. Further use of relative terms such as “vertical”, “horizontal”, “up”, “down”, and “side-to-side” are used in a relative sense to the normal orientation of the apparatus.

Claims

What is claimed is:

1. A self-reliant manipulator, comprising: a continuum robot; a feeding tube coaxially mounted around the continuum robot, the feeding tube extended between a proximal end of the feeding tube and a distal end of a feeding tube, the feeding tube moveable relative to the continuum robot along a main axis of the continuum robot; an annular body with a central passthrough configured to be mounted at an entrance to a body cavity, the annular body configured to allow passage of the continuum robot and the feeding tube through the central passthrough of the annular body into the body cavity; a stiffening cover extended between a first end of the stiffening cover and a second end of the stiffening cover, the first end of the stiffening cover disposed between an inner surface of the feeding tube and an outer surface of the continuum robot, the first end of the stiffening cover attached to the proximal end of the feeding tube, the stiffening cover extended within the feeding tube between the proximal end and the distal end, the stiffening cover folded back onto an outer surface of the feeding tube at the distal end, the stiffening cover further extended over the outer surface of the feeding tube between the distal end of the feeding tube and the annular body, the second end of the stiffening cover attached to the annular body, the stiffening cover further pulled out from within the feeding tube and deployed onto the outer surface of the feeding tube in response to the feeding tube moving along the continuum robot relative to the annular body; and a stiffness adjustment mechanism coupled to the stiffening cover, the stiffness adjustment mechanism configured to regulate a stiffness of a portion of the stiffening cover disposed on the outer surface of the feeding tube. The self-reliant manipulator of claim 1 , further comprising a sealing mechanism mounted on the distal end of the feeding tube, the sealing mechanism comprising: a ball bearing comprising an annular bearing body mounted around the distal end of the feeding tube and a plurality of balls annularly arranged inside the annular bearing body; and a pair of retaining rings mounted around the distal end of the feeding tube at both lateral sides of the ball bearing, the pair of retaining rings coaxial with the ball bearing, wherein, the stiffening cover extends out of the distal end of the feeding tube and folds back around a first retaining ring of the pair of retaining rings onto the outer surface of the feeding tube, the stiffening cover further extends through the bearing unit passing between the plurality of balls and the outer surface of the feeding tube and over a second retaining ring of the pair of retaining rings. The self-reliant manipulator of claim 2, wherein the plurality of balls of the bearing unit are configured to press the stiffening cover onto the outer surface of the feeding tube to provide a seal between an outer confined space and an inner confined space between the stiffening cover and the feeding tube, the outer confined space comprising a confined space between the stiffening cover and the outer surface of the feeding tube, the inner confined space comprising a confined space between the stiffening cover and the inner surface of the feeding tube. The self-reliant manipulator of claim 3, wherein the annular body further comprises an annular aperture connected in fluid communication with the outer confined space between the stiffening cover and the outer surface of the feeding tube. The self-reliant manipulator of claim 4, wherein the stiffness adjustment mechanism comprises a pressurized fluid source connected to the outer confined space, the pressurized fluid source configured to inject a pressurized fluid into the outer confined space, the stiffening cover configured to be stiffened in response to the pressurized fluid injected into the outer confined space. The self-reliant manipulator of claim 4, wherein the stiffness adjustment mechanism comprises a plurality of inflatable pipes/inverse inflatable pipes, the annular aperture further configured to allow for insertion of the plurality of inflatable pipes/inverse inflatable pipes into the outer confined space, the stiffening cover configured to be stiffened in response to the plurality of inflatable pipes/inverse inflatable pipes inserted into the outer confined space. The self-reliant manipulator of claim 2, wherein the stiffening cover comprises: an inner layer made of a plurality of longitudinal elements; and an outer layer made of an elastic material, the outer layer disposed around and encompass the inner layer. The self-reliant manipulator of claim 7, wherein the plurality of balls of the bearing unit are configured to press the stiffening cover onto the outer surface of the feeding tube to provide a seal between an outer confined space and an inner confined space between the outer layer and the inner layer of the stiffening cover, the outer confined space comprising a confined space between the outer layer and the inner layer of a portion of the stiffening cover extend over the outer surface of the feeding tube, the inner confined space comprising a confined space between the outer layer and the inner layer of a portion of the stiffening cover extend within the feeding tube. The self-reliant manipulator of claim 8, wherein the annular body further comprises an annular aperture connected in fluid communication with the outer confined space between the outer layer and the inner layer of the stiffening cover. The self-reliant manipulator of claim 9, wherein the stiffness adjustment mechanism comprises a vacuum pump connected to the outer confined space, the vacuum pump configured to provide negative pressure within the outer confined space, the outer layer tightened around the inner layer in response to the negative pressure applied within the outer confined space. The self-reliant manipulator of claim 2, further comprising a cover retraction mechanism, the cover retraction mechanism comprising: an annular cover housing attached to the proximal end of the feeding tube, the annular cover housing comprising a central hole, the central hole configured to allow for passage of the continuum robot, the annular cover housing moveable relative to the continuum robot along the main axis of the continuum robot; and a plurality of spring-loaded tendons configured to connect the annular housing to the first end of the stiffening cover. The self-reliant manipulator of claim 11, wherein the plurality of spring-loaded tendons comprises: a plurality of spiral springs mounted within the cover housing; and a plurality of tendons coupled to the corresponding plurality of spiral springs, respective first ends of the plurality of tendons attached to respective plurality of spiral springs and respective second ends of the plurality of tendons attached to the first end of the stiffening cover.