HK40013614A - Steerable surgical robotic system - Google Patents

Description

Steerable surgical robotic system

Cross Reference to Related Applications

The present application claims the benefit of U.S. provisional application serial No. 62/612,233 entitled "battery minor rolling SYSTEM" filed on 12/29/2017, which is incorporated herein by reference in its entirety.

Technical Field

The present description relates to the field of robotic medical procedures in which a guidewire is introduced into a body through a catheter. More particularly, the present description relates to the field of steerable surgical robotic systems for controlling movement of guidewires and catheters in robotic surgery.

Background

Introduction catheters are known for delivering elements such as stents, balloons or other devices to a desired location within a body lumen. In these applications, a guidewire is introduced into a body lumen and maneuvered to a desired location within the body lumen using radiopaque markers at its ends, which are radiographically visualized by a surgeon. Such manipulation may include moving the orientation of the distal tip of the guidewire relative to the rest to manipulate the tip into a tortuous portion of the lumen or into a branch lumen, etc. Once the distal tip is properly positioned within the body, a sheath, which may include a deployable element such as a stent or balloon thereon or therein, is advanced over the wire to position its distal end at a desired location within the patient.

A need has arisen to robotically introduce such catheters in which an operator, such as a surgeon, controls a joystick or other control element connected to a controller while viewing the tip of the guidewire and the adjacent anatomy of the patient on a display screen. Robotic controllers for independently advancing a guidewire and a guidewire within a patient are known. For example, in one such controller, the sheath can be advanced or retracted by a pair of rollers, the guidewire can be moved within the sheath, and the guidewire can be inserted therein from a position offset from the longitudinal axis of the sheath. As a result, relative movement of the sheath and guidewire cannot be easily controlled, including the desirable ability to rotate the guidewire about its own axis to orient its tip in a desired direction for further advancement within the body (e.g., within a body lumen)

Disclosure of Invention

Provided herein is a steerable surgical robotic system for positioning a catheter comprising a sheath and a guidewire within a patient's body, comprising: a sheath driver configured to advance and retract a sheath having a hollow interior along a sheath advancement and retraction path extending therein; and a guidewire drive configured to advance and retract a guidewire along a guidewire advancement and retraction path extending therein, wherein each of the sheath advancement and retraction path and the guidewire advancement and retraction path extends between the pair of rollers in the respective sheath and roller drives, and the paths are parallel to each other.

Drawings

Fig. 1 is an isometric view of a cart holding a robotic controller assembly of a steerable surgical robotic system having a steerable guidewire that can be inserted into a sheath and then fed, advanced and maneuvered through it into position within the body of a human or animal patient.

Fig. 2A is an isometric view of the robotic controller assembly shown in fig. 1.

Fig. 2B is an isometric view of the distal portions of the sheath and guidewire of fig. 2A.

Fig. 3A is a plan view of the robotic controller assembly shown in fig. 2A.

Fig. 3B is a plan view of the distal portion of the sheath and guidewire of fig. 3A.

Fig. 4A is an isometric rear view of the robotic controller assembly shown in fig. 2A.

Fig. 4B is a perspective view of the distal portions of the sheath and guidewire of fig. 4A.

Fig. 5A is a rear isometric view of the robotic controller assembly shown in fig. 4A, wherein the robotic controller has been actuated to rotate the guidewire relative to the sheath.

Fig. 5B is a perspective view of the distal portions of the sheath and guidewire of fig. 5A.

Fig. 6A is an isometric view of the robotic controller assembly of fig. 2A, wherein the robotic controller assembly has been actuated to change the relative position of the sheath and guidewire therein relative to fig. 2A.

Fig. 6B shows the sheath having moved to the left in the figure while the guidewire position remains stationary.

Fig. 7 is a block diagram of a controller architecture for controlling the operation of a robotic controller assembly.

Fig. 8A and 8B are isometric views of a bendable end of the guidewire of fig. 2A-6A.

Fig. 8C and 8D are end views of the guidewire.

Fig. 9A and 9B are cross-sectional views of a connection paradigm for electrically connecting electrodes on a bendable portion of a guidewire to a power source.

Detailed Description

Herein, a steerable robotic system 10 is provided that is mounted in a guide tray 12 suspended on an arm 14 extending in a cantilevered fashion from a base 16. The base 16 is shown here mounted on a movable cart 18 that includes a plurality of lockable wheels 20 that allow a surgeon or other technician to move the cart 18 to a desired position adjacent the patient and lock the wheels 20 from moving, thereby locking the cart 18 in place. The base 16 is movable in translation in a vertical direction relative to the cart 18. The arm 14 here comprises an arcuate boom portion 22, and a first sub-arm 24 is pivotally connected to the boom portion 22 by a swivel connection 26 and supported in a horizontal plane by the swivel connection 26. The second sub-arm 28 is also pivotally connected at its first end to the first sub-arm 24, and a right angle hanger 30 is pivotally connected to its opposite distal end 30. The pivotal connection of the second sub-arm 28 to the first sub-arm 24 allows for controlled swinging movement of the distal end 30 of the second sub-arm about an arc centered on the pivotal connection of the second sub-arm to the first sub-arm 24 such that the distal end 30 can move up or down relative to the support surface on which the wheels 20 of the cart 18 are located. A right angle support 32 is pivotally suspended from the distal end 30 and includes first and second portions connected at another pivot 34, with the second portion being connected to the guide tray 12. The guide tray 12 can be positioned relative to the horizontal and vertical by the user via the handle 36 thereon through the swivel connection of the arms 22, 24 and 28 and the right angle support 32. As a result, the five degrees of freedom in which the guide tray 12 is positioned relative to the cart 18 include 3 translational degrees of freedom, one pitch motion, and one yaw motion.

A robotic controller 50 is disposed in the guide tray 12 and supported by the guide tray 12, a flexible sheath 52 (e.g., an outer sheath of a catheter) extends from the robotic controller 50 and a steerable guidewire 54 extends in the sheath 52 and ultimately from the sheath 52 (see, e.g., fig. 2A). The guide tray 12 includes: a trough-like support area 38 on which a robot controller 50 is mounted and supported; and a funnel-shaped hood 40 extending from one end of the support region 38 and having a guide opening 42 of reduced diameter at its inwardly tapered end. A sheath 52 having a steerable guidewire 54 movably disposed therein extends from the robotic controller 50 out of the opening 42. The guide tray 12 can be positioned relative to the patient and relative to the sheath 52 extending inwardly into the incision of the patient in a desired orientation to allow the steerable guidewire 54 to reach a treatment site within the patient.

Herein, initially, a sheath 52 with a guidewire 54 therein is manually introduced into the patient. The separate visual field to view the distal ends of the sheath 52 and guidewire 54 or the radiopaque markers on the distal ends of the sheath 52 and guidewire 54 may be combined with radiological imaging of the patient's body to thereafter guide the distal ends of the sheath 52 and guidewire 54 to a desired location within the patient's body.

Referring to fig. 2A and 3A, the robotic controller 50 from which the sheath 52 and guidewire 54 extend is shown in an isometric view (fig. 2A) and a plan view (fig. 3A). In this configuration of the robotic controller, the robotic controller 50 includes a sheath driver 62 and a guide wire driver 64, wherein the sheath driver 62 is fixedly connected to a base 60 of the robotic controller that is fixed to the guide tray 12, and the guide wire driver 64 is slidably connected to the base 60. In this configuration, each of the sheath driver 62 and the guidewire driver 64 is configured to allow fine movement control of the positioning of the guidewire 54 and the sheath 52 relative to the base 60, and additionally the guidewire 54 may be moved relative to the sheath 52 by slidably moving the guidewire driver 64 along the base 60. Thus, if each of the sheath driver 62 and the guidewire driver 64 remain stationary relative to one another and they each simultaneously move the sheath 52 and the guidewire 54 toward or away from the opening 42 in the guide tray 12, the sheath 52 and the guidewire 54 do not move relative to one another despite moving relative to the opening 42, and thus through the incision in the patient, and thus into the patient. Alternatively, where the sheath driver 62 moves the sheath 52 relative thereto, the guidewire driver 64 may move itself, with the guidewire 54 remaining stationary relative thereto, to the effect that the sheath 52 and guidewire 54 move simultaneously relative to the opening 42, but do not move relative to each other. In either case, the distal tip 56 of the guidewire 54 may also be controllably advanced away from the distal end 58 of the sheath 52, or retracted toward the distal end 58 or even into the distal end 58, by operation of the sheath driver 62 and guidewire driver 54 with a controller (fig. 7), as the guidewire is inserted into tortuous anatomy.

The sheath driver 62 includes a base 61 that is fixedly supported on the end of a flange plate 66 that extends generally perpendicular to the mounting base 60, and here, the base 61 forms a roller housing with two pairs of pinch roller assemblies 68a, 68B (fig. 3A, 3B). Each of the pair of pinch roller assemblies 68a, 68b includes two rollers 70a, 70b rotatably supported on drive shafts 72a, 72b extending generally perpendicular to the drive path of the jacket 52. One of the pair of drive shafts 72a, 72b of one of the pair of rollers 70a, 70b (here, the shaft 72b of the roller 70b of the pinch roller assembly 68 b) is coupled to a motor 73 (here, its output shaft 74 has a motor that can be moved in an arc that is finely controlled) to allow small arc movements of its output shaft 74. The output shaft 74 is connected to a gear box 75 having a pair of bevel gears dedicated to driving the drive shaft 72b of the roller 70b of the roller assembly 68 b. Here, the center line of the output shaft 74 is substantially parallel to the drive path of the jacket 52, and when the drive shafts 72a, 72b are substantially perpendicular to the drive path, a pair of bevel gears transmit the rotation of the output shaft 74 while converting the direction of the center line in which the rotation occurs from being parallel to the drive path to being perpendicular to the drive path. To achieve the pinch nature of the pinch roller assemblies 68a, 68b, the drive shafts 72a of the rollers 70a are disposed on slidable housings 67a, 67b, and each slidable housing is spring-loaded by springs 69a, 69b or other biasing mechanism to urge the outer peripheral surface of the roller 70a toward the corresponding outer peripheral surface of the roller 70b to grip the sheath 52 extending therebetween. Since the roller 70b or pinch roller assembly 68a is physically driven, pinching the jacket between the rotating rollers 70a, 70b of pinch roller assembly 68b causes a corresponding linear movement of the jacket sandwiched therebetween, and movement of the jacket 52 causes rotation of the rollers 70a, 70b of pinch roller assembly 68 b. Since the rollers 70a, 70b act as pinch rollers that pinch the outer surface of the jacket 52 therebetween, only one of the two rollers 70a, 70b of each pair 68a, 68b need be driven, the other roller providing a driven roller surface. Alternatively, a second pair or set of bevel gears connected to a second output shaft of the motor 74 may be provided to drive the rollers 70b of the compression roller assembly 68 a.

The guidewire driver 64 is linearly movable relative to the sheath driver 62, and it also includes the same roller configuration as the sheath driver 62. The wire drive 64 includes a base 80 including a lower slide portion 82 configured to be received within a slide bar recess 84 of the mounting base 60, a rear drive mount 86 extending upwardly (in a direction away from the mounting base 60), and a forward flange 90 extending therefrom. The mounting base 60 includes a side flange 88 that extends generally parallel to a forward side flange 90. The main motor 92 (here, a stepper motor or servo motor capable of controlled small angular movement of its output shaft 94) is coupled to a first end 98 of a threaded rod 96 via the output shaft 94. A second end 100 of the threaded rod 96 is supported by bearings (not shown) in an opening 102 of the side flange 88. The front flange 90 includes a threaded opening 104 therethrough (here, the threaded opening 104 extends through a boss 106 extending from a side of the side flange 90 facing the main motor and is axially aligned with the center of the shaft 94 and the opening 102 in the side flange 88). Stabilizing openings 110, 112 are provided through the flanges 88, 90, respectively, for receiving stabilizing rods (not shown) therethrough that are supported by additional elements of the tray 12 or base to prevent arcuate movement of the side flanges 90 about the axis of the output shaft 94. The main motor 92 is mounted to the mounting base 60 adjacent to the flange plate 66 and is therefore fixed in position relative to the side flange 88. Thus, rotation of the main motor 92 (and thus the threaded rod 96 in threaded engagement with the threads in the boss 106) results in linear movement of the forward flange 90 relative to the side flange 88, and thus corresponding linear movement of the guide wire drive 64.

As previously discussed, the guidewire driver 64 has the same general configuration as the sheath driver 62 and includes a base 61 forming a roller housing and two pairs of pinch roller assemblies 68a, 68 b. Each of the pair of pinch roller assemblies 68a, 68b includes two rollers 70a, 70b rotatably supported on drive shafts 72a, 72b extending generally perpendicular to the drive path of the guide wire 54 therethrough. One of the pair of drive shafts 72a, 72b of one of the pair of rollers 70a, 70b (here, the shaft 72b of the roller 70b of the pinch roller assembly 68 b) is coupled to a motor (here, its output shaft 74 has a motor 73 that can be moved in an arc that is finely controlled) to allow small arc movements of its output shaft 74. The output shaft 74 is connected to a gear box dedicated to driving shaft 72b which drives roller 70b of roller assembly 68 b. Here, the center line of the output shaft 74 is substantially parallel to the drive path of the jacket, and when the drive shafts 72a, 72b are substantially perpendicular to the drive path, a pair of bevel gears transmit the rotation of the output shaft 74 while converting the direction of the center line in which the rotation occurs from being parallel to the drive path to being perpendicular to the drive path. To achieve the pinching nature of the pinch roller assemblies 68a, 68b, the drive shafts 72a of the rollers 70a are disposed on slidable housings 67a, 67b, and each slidable housing is spring-loaded by springs 69a, 69b or other biasing mechanism to urge the outer peripheral surface of the roller 70a toward the corresponding outer peripheral surface of the roller 70b to grip the guidewire 54 extending therebetween. Since roller 70b or pinch roller assembly 68a is physically driven, pinching of the guidewire 54 between the rotating rollers 70a, 70b of pinch roller assembly 68b results in corresponding linear movement of the guidewire 54 sandwiched therebetween, and movement of the guidewire 54 results in rotation of the rollers 70a, 70b of pinch roller assembly 68 b. Since the rollers 70a, 70b act as pinch rollers that pinch the outer surface of the guide wire 54 therebetween, only one of the two rollers 70a, 70b of each pair 68a, 68b of drive rollers 70a, 70b is required, the other roller providing a driven roller surface. Alternatively, a second pair or set of bevel gears connected to a second output shaft of the motor 74 may be provided to drive the rollers 70b of the compression roller assembly 68 a.

In contrast to the base 61 of the sheath driver 62, the base 61 of the guide wire driver 64 is mounted at its rear end 114 to a stub shaft 116 supported in a bearing 118 in the driver mount 86, the stub shaft 116 in turn being connected to a timing gear 120. Referring to fig. 4A, a rotary drive motor 122 is attached to the base 80, and a drive timing gear 124 is attached to its output shaft that extends through an opening 128 in the driver mount 86 and is supported within a bearing 126 in the opening 128. Idler pulley 127 is also supported on bearings in openings in drive mount 86. Timing belt 130 of FIG. 5A extends around timing gear 120, idler gear 127, and drive timing gear 124, whereby operation of the motor causing rotation of its output shaft 94 causes timing belt 130 to move, resulting in rotation of timing gear 120 in the +/- θ direction. This in turn causes the base 61 of the guidewire driver 64 to rotate with the stub shaft about the stub shaft 116 axis. This rotational movement causes a corresponding rotation of the guidewire 54 within the guidewire drive 64 as the guidewire 54 is pinched between the rollers 68a, 68 b. As shown in fig. 4B, where the sheath driver 62 and the guide wire driver 64 have the same orientation, the tip portion 56 of the guide wire here extends generally toward the Y-axis along a curved portion extending from a portion of the guide wire 54 extending in the Z-direction. The orientation of the tip 56 need not be independently modified, except that by rotating the base 61 portion of the wire drive 64 about the minor axis to the position shown in fig. 5B, the orientation of the tip portion 56 of the wire 54 now extends generally toward the Y-axis along a curved portion extending from a portion of the wire 54 in the Z-direction.

Herein, driven rollers 70b and driven rollers 70a of pinch roller assemblies 68a, 68b of each of sheath driver 62 and guidewire driver 64 allow translational movement of guidewire 54 and sheath 52 within sheath driver 62 and guidewire driver 64 in the +/-Z direction of fig. 4A. Additionally, the entire guidewire driver 54 is translationally movable in the Z-direction relative to the sheath driver 62 as shown by its relative positions of fig. 4A and 5A as compared to that shown in fig. 6A. In fig. 6A, the operation of the main motor 92 to rotate the threaded rod 96 attached thereto has moved the guide wire driver 64 toward the sheath driver 62 fixed to the base 60. As a result, if the driven roller 70b of the guidewire driver remains stationary, the guidewire 54 will be urged into the collar 140 at the proximal end of the sheath 52, through which collar 140 the guidewire 54 is introduced into the interior of the sheath 52. This can result in buckling of the region of the sheath 52 between the ferrule 140 and the sheath driver 62. Thus, the collar 140 can be physically connected (connection not shown) to the side flange 90 of the guide wire drive 64, thus moving translationally as the guide wire drive 64 moves translationally. To achieve this movement, the jacket 52 must be driven in the same direction by the driven rollers 70b of the pinch roller assembly 68b of the jacket driver 62 at the same translational speed as the translational movement of the front flange 90. In addition, comparing fig. 2B to 6B, translational movement of the anterior flange 90 from its position in fig. 2A to its position in fig. 6B indicates that the sheath 52 has moved to the left in the figure while the guidewire 54 remains stationary. This is accomplished by the controller operating the guidewire motor 73 to rotate the driven roller 70b of its pinch roller assembly 68b to maintain the position of the guidewire 54 stationary relative to the guide tray 12, thus allowing the sheath 52 to move relative to the guidewire 54 extending therein and from the proximal and distal ends thereof.

Herein, the drive direction of the sheath 52 within the sheath driver 64 and the guidewire 54 within the guidewire driver 64 is fixed by the relative orientation of the sheath driver 62 and the guidewire driver 64. In implementations such as that shown in fig. 2B, the guidewire 54 is urged directly into the collar at the proximal end of the sheath 52 by the driven roller 70B and the remaining rollers urging thereon. In other words, the direction in which the roller pushes against the guidewire is along the centerline of the interior volume of the sheath 52. Thus, when the guidewire is rotated by the guidewire driver, the portion thereof within the sheath 52 and extending from the distal end 58 thereof will likewise rotate in the same direction. In contrast, in prior devices where the guidewire was introduced at an angle to the sheath, the guidewire would bend or loop outside of the introduction site and the distal end of the guidewire was controllably rotationally unstable. Additionally, when the collar of the sheath 52 is physically secured to the side flange 90 of the guide wire drive 64, the sheath 52 may be held solely between the side flange 90 of the sheath drive 62 and the roller 70 to extend along a linear path by proper operation of the roller in terms of relative movement of the guide wire drive 64 with respect to the sheath drive 62. Further, the rollers 70 of each of the sheath and guidewire drivers 62, 54 may include stops aligned along the advancement/retraction direction of the sheath 52 or guidewire 54 to ensure the relative position of the sheath 52 and guidewire 54 in their respective drivers 62, 64. This further ensures that the guidewire is less likely to bend or loop outwardly as it is advanced into the proximal end of the sheath 52 or rotated proximally relative to the sheath 52. With proper alignment of the sheath driver 62 and the guidewire driver 64 relative to each other, the paths of the sheath and guidewire through their respective drivers may be parallel and collinear.

Referring to fig. 7, a control system 132 of the robot controller is schematically shown. The control system includes programmable memory including at least one random access memory 134 for temporarily storing control programs, read only memory 136 for permanently storing operating parameters of the system and control programs, and a processor 138 configured to operate and control the robotic controller 50 using the control programs. Thus, the controller is hard-wired or wirelessly connected to the main motor 122 and the motor driving the drive shaft 72b of the pinch roller assembly 68b to provide control signals thereto to allow selective advancement and retraction of the sheath 52 and guidewire 54 and rotation of the guidewire 54 (all under control of the control system 132). This allows for various relative movements of the guidewire 54, the sheath 52, and the guidewire driver 64 and the sheath driver 62.

To properly position the distal end 58 of the sheath 52 within the patient lumen, the sheath 52, along which the guidewire 54 extends, is initially introduced into the patient incision and advanced along the lumen while being radiographically imaged for viewing by the surgeon. This may be done manually initially, after which the surgeon actuates a joystick or other device to simultaneously or independently control the advancement, retraction, and rotation of the guidewire and sheath, as well as the bending orientation of the distal tip 56, while radially viewing the lumen, guidewire distal tip 56, and sheath distal end 58. As a result, the surgeon is able to guide the guidewire (and thus the sheath) to a desired location within the patient.

Here, to effect a transition in the orientation of the distal tip 56 of the guidewire between that shown in fig. 1 and that shown, for example, in fig. 4B, the guidewire includes a bendable end portion 150. Fig. 8A is a perspective view of an embodiment of the bendable portion 150, showing the bendable portion 150 in a straight mode. The curvable portion 150 comprises an ion electroactive polymer actuator 210 comprising a polymer electrolyte layer 211, the polymer electrolyte layer 211 being disposed adjacent to the distal end 200 of the guide wire 54 and centrally disposed within a plurality of independently energizable electrodes 212 angularly distributed thereabout. Each of the plurality of electrodes 212, which together surround the outer surface 213 of the polymer electrolyte layer 211, is connected to the distal end 123 of the conductive filament 152 (fig. 9A, 9B), and an electrical signal or current may be supplied to the connected electrode 212 through the conductive filament 152. In one embodiment, the angularly distributed electrodes 212 are equiangularly distributed around the outer surface 213 of the polymer electrolyte layer 211. For example, and without limitation, in the embodiment of fig. 8A, the ion electroactive polymer actuator 210 may include four angularly distributed electrodes 212 whose centerlines are separated from each other by about 90 degrees (1.571 radians). It will be appreciated that each of the plurality of electrodes 212 occupies a circumferential span along the surface of the polymer electrolyte layer, and thus the "angular separation" may be in terms of the centerline 217 of the electrode, rather than the adjacent edges of the electrode (which would be closer to the adjacent edges of the adjacent electrodes). In some embodiments, the electrodes are spaced apart in a manner that provides a significant gap between adjacent electrodes as an insulating channel 216. Selective application of current/voltage to one or more electrodes 212 causes the bendable portion 150 to move between its orientation in fig. 8A and its orientation in fig. 8B.

In one embodiment, the bendable end portion 150 of the guidewire 54 is configured as an ion electroactive polymer actuator 210. In one embodiment, the ionic electroactive polymer actuator 210 includes a polymer electrolyte layer 211 made of PVDF-HFP impregnated with EMITF (as the electrolyte). Alternatively, other embodiments of the ion electroactive polymer actuator 210 can include a polymer electrolyte layer 211 comprising, for example, Aciplex^TM(available from Asahi Kasei chemical Corp, Tokyo, Japan),(available from AGC Chemical America, Inc. of Exton, Pa.) of,F sequence (FumatechBWT GmbH available from Bietigheim-Bissingen, Germany Federal republic) or(available from Chemours Company of Wilmington, Del., USA) of at least one perfluorinated ionomer.

In one embodiment, the electrode 212 may include one of platinum, gold, a carbon-based material, or a combination thereof (e.g., a composite material). In other embodiments, for example and without limitation, the carbon material may include carbide-derived carbon (CDC), Carbon Nanotubes (CNTs), graphene, a composite of carbide-derived carbon and the polymer electrolyte layer 211, and a composite of carbon nanotubes and the polymer electrolyte layer 211. In an exemplary embodiment, as shown in fig. 9, the electrode 212 is bi-layered and includes: a composite layer 212a of carbon (CDC and/or CNT) and PVDF-HFP/EMITF and a gold layer 212b thereon. The electrode 212 may be integrated on the outer surface 213 of the polymer electrolyte layer 211 using any suitable technique. For example, and without limitation, the metal electrode 212 may be deposited thereon using an electrochemical process (e.g., a platinum or gold electrode). Alternatively, the bilayer electrode 212 may be prepared and integrated on the outer surface 213 by: a composite layer is sprayed on the outer surface 213, a gold layer is sprayed on the composite layer, and then the two layers are integrated using a reflow process. Details of the reflow process are discussed in PCT application No. PCT/US17/16513, which is incorporated herein by reference in its entirety.

The bendable portion 150 is selectively and controllably deformable into a bending mode by selective energization of one or more of the plurality of electrodes 212, as will be described in greater detail below. Fig. 8B is an isometric view of a portion of the curvable portion 150 of fig. 8A in a deformed or bent mode. Each of the plurality of electrodes 212 is connected to a distal end 220 of the conductive filament 152 (fig. 9A), and an electrical signal can be applied through the conductive filament 152 to the electrode 212 to which the filament 152 is connected, causing metal cations within the polymer electrolyte layer 211 to move in a direction determined by the applied electrical signal. In a portion of the polymer electrolyte layer 211 disposed near the anode, this cation migration generated by the applied electric signal causes the polymer electrolyte layer 211 to expand, bending or warping in the direction of the remaining unexpanded portion. As a result, the magnitude and direction of the bending deformation of the polymer electrolyte layer 211 of the ionic electroactive polymer actuator 210 can be controlled by strategically selecting the electrodes 212 to be energized and adjusting the electrical signals applied to those electrodes 212 through the conductive filaments 152.

Alternatively, where the bendable portion 150 is observed to be in the deformation mode without application of one or more electrical signals to one or more of the plurality of electrodes 212, the magnitude of the observed deflection may be used to determine the magnitude and direction of the external force applied to the bendable portion 150, or alternatively, where application of a known current to the electrodes 212 fails to produce an expected deformation of the bendable portion 150, the difference between the expected deformation and the actual deformation (if any) may be used as an indicator of the magnitude of the external force applied to the bendable portion 150 of the guidewire 52.

Fig. 8C is a cross-sectional view of the bendable portion 150 of fig. 8A and 8B, illustrating one embodiment in which a selected first set of four electrical signals are applied to four circumferentially distributed electrodes 212 disposed about the outer surface 213 of the polymer electrolyte layer 211 to provide two degrees of freedom (e.g., bending along the X-axis direction and/or the Y-axis direction). Fig. 8C illustrates an electrical signal that may be applied to the plurality of angularly distributed electrodes 212 to bend the bendable portion 150 in the direction of arrow 3. It will be appreciated that in addition to applying a positive charge (potential) to the top electrode 212 of fig. 8C, and also in addition to applying a negative charge (potential) to the bottom electrode 212 of fig. 8C, applying positive charges (potentials) to the electrodes 212 on the left and right sides of the bendable portion 150 of fig. 8C may result in a different amount of deformation than would occur if a positive charge (potential) were applied to the top electrode 212 of fig. 8C and a negative charge (potential) were applied to the remaining electrodes 212. It will be appreciated that the user may select a plurality of electrical signals that produce the user desired deformation.

Fig. 8D is a cross-sectional view of the bendable portion 150 of fig. 8A and 8B, showing another embodiment where a second selected set of four electrical signals are applied to circumferentially distributed electrodes 212 disposed around the polymer electrolyte layer 211. Fig. 8D shows that positive charges (electric potentials) are applied to the electrode 212 on the top of the bendable portion 150 of fig. 8D and also to the electrode 212 on the right side of the bendable portion 150 of fig. 8D, and fig. 8D also shows that negative charges (electric potentials) are applied to the electrode 212 on the bottom of fig. 8D and also to the electrode 212 on the left side of fig. 8D. The deformation of the polymer electrolyte layer 211 is caused by applying these charges (potentials) in the direction of the arrow 4.

It will be appreciated from fig. 8C and 8D that by strategically controlling the sign (+, -) and magnitude of the charge imparted to each electrode 212, the bendable portion 150 may bend in multiple directions and have varying degrees of deformation or deflection. While the embodiment shown in fig. 8A-8D shows the curvable portion 150 including four electrodes 212, it will be understood that the curvable portion 150 of the guidewire 54 may include less than four or more than four electrodes 212, and these other embodiments will have different deflection and deformation orientation capabilities, thus providing more or less degrees of freedom.

The conductive filaments 152 may be interconnected with the electrodes 212 in various configurations using any suitable connection technique. For example, a conductive paste or laser welding may be used to physically and electrically connect the conductive filaments 152 and the electrodes 212. Fig. 9A and 9B illustrate a cross-section of an ionic electroactive polymer actuator 210, showing one embodiment of the physical and electrical connection of the conductive filaments 152 and electrodes 212, which is disclosed in provisional application No.62/539,346 and incorporated herein by reference in its entirety. Here, the conductive filaments 152 are interconnected (e.g., integrated (see, e.g., fig. 9A) or embedded (see, e.g., fig. 9B)) with at least a portion of the respective electrodes 212 at the proximal end 202 of the ionic electroactive polymer actuator 210 using a conductive paste or laser welding. A polymeric sleeve 204 is then provided to facilitate guidewire maneuverability within the body lumen or passage. A polymeric sleeve 204 is overlaid over the guidewire core 206, a portion of the proximal end 202, and the conductive wire 152 connected thereto to securely hold them together.

The proximal end of the guidewire 54 is further coupled to a connector 300 (see, e.g., fig. 4A), and the connector 300 may be further electrically connected to an electrical controller (not shown). The electrical controller is configured to selectively control an electrical charge carried by the conductive wire 152 and imparted to the plurality of electrodes 212 to control and manipulate the bendable portion 150 of the guidewire. In some embodiments, the electrical controller may include a processor (not shown) that calculates the value of the electrical signal applied to the electrodes in response to a user input signal from a master controller (not shown). For example, the master controller may include a joystick that enables a user to input bending control signals to the electrodes 212 of the bendable portion 150 to provide two degrees of bending freedom through the electrical controller.

Herein, a mechanism is provided for locally manipulating the distal tip 56 of the guidewire 54 using an electroactive polymer and electrode configuration, as well as the ability of the distal tip 56 to advance relative to the distal end 58 of the surrounding sheath 52, and the ability to rotate the guidewire 54, thus moving the distal tip in a circular path (pat), the radius of which depends on its bending caused by the use of the electroactive polymer and electrode, to move the distal tip 56 relative to the rest of the guidewire 56. Thus, upon use by a surgeon, the distal end 58 of the sheath is first introduced into the patient (e.g., within the patient's body cavity). Here, the portion of the sheath 52 adjacent the distal end 58 includes one or more radioactive markers to allow the distal end to be imaged radially within the body lumen. Then, when a tortuous lumen structure is encountered, the distal tip 56 of the guidewire 54, which is also radioactively labeled, may be advanced relative to the distal end 58 of the sheath 52 by operating the motor 73 of the guidewire driver 64 to rotate at least one roller 70 thereof, thereby advancing the guidewire relative to the distal end 58 of the sheath 52. The surgeon, through operation of a joystick or other device connected to the controller, can control the advancement of the guidewire 54, control the direction and amount of bending t resulting from operation of the electrodes and electroactive polymer as a result of the controller supplying power to selected electrodes 212, and once bending of the end of the guidewire 54 is achieved, move the distal tip along an arc to align it with another portion or branch of the lumen into which the distal tip 56 is then advanced. The sheath 52 can then be advanced over the guidewire, if necessary, and the sequence of operations repeated until the distal end of the sheath is positioned at the desired location within the patient.

For example, the distal end of the sheath may carry a stent, balloon or other deployable device. Thus, when the distal end of the sheath has been advanced to the desired lumen location, the stent or balloon can be deployed and the sheath 52 and guidewire removed from the patient.

Claims (7)

1. A robotic controller for positioning a catheter including a sheath and a guidewire within a patient, the robotic controller comprising:

a sheath driver configured to advance and retract a sheath having a hollow interior along a sheath advancement and retraction path extending therein;

a guidewire driver configured to advance and retract a guidewire along a guidewire advancement and retraction path extending therein; wherein

Each of the sheath advancement and retraction path and the guidewire advancement and retraction path extends between a pair of rollers in the respective sheath and roller drives, and the paths are parallel to each other.

2. The robotic controller of claim 1, wherein the sheath advancement and retraction path and the guidewire advancement and retraction path extend between and are collinear between the pair of rollers.

3. The robotic controller of claim 1, wherein the sheath driver is connected to a base, and the guidewire driver is slidably supported on the base and movable relative to the base and relative to the sheath driver.

4. The robotic controller of claim 3, wherein the guidewire driver further comprises a sheath attachment portion for physically securing a proximal end of a sheath extending from the sheath driver thereto.

5. The robotic controller of claim 3, further comprising a main motor coupled to the base and a lead screw extending therefrom, wherein the guide wire driver is threadably coupled to the lead screw.

6. The robotic controller of claim 3, wherein the guidewire drive further comprises a roller housing and a roller housing flange, wherein the roller housing extends from the roller housing flange.

7. The robotic controller of claim 6, wherein the guidewire drive further comprises a rotary motor connected to the roller housing by a belt.