Abstract:
A system for traversing an arterial occlusion in an artery includes a housing sized to fit in a palm of a user, an elongate drive tube configured to be rotated by the housing, the drive tube including an axially extending passage, a cylindrical member, configured to be rotationally coupled to the drive tube, such that a distal tip of the cylindrical member may be delivered to a location adjacent the arterial occlusion when the cylindrical member is coupled to the drive tube, and wherein grasping and activating the housing such that the drive tube is rotated, thereby causes the distal tip of the cylindrical member to be rotated, the rotation of the distal tip including at least a component of linear oscillation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a division of U.S. patent application Ser. No. 14/559,874, filed on Dec. 3, 2014, and incorporated in its entirety by reference herein for all purposes, which is a continuation of U.S. patent application Ser. No. 12/658,629, filed on Feb. 9, 2010 and incorporated in its entirety by reference herein for all purposes, which claims the benefit of priority to U.S. Provisional Appl. No. 61/151,388, filed on Feb. 10, 2009, which is incorporated in its entirety by reference herein for all purposes. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    Embodiments of the present invention generally relate to surgical guidewire utilization in surgical procedures and, more particularly, to a method and apparatus for manipulating a surgical guidewire. 
         [0004]    2. Description of the Related Art 
         [0005]    A surgical guidewire (referred to herein also as a guidewire) is typically a semi-rigid probe used as an initial access point for performing in endovascular surgical procedure. The guidewire is twisted, bent, and otherwise maneuvered through an access vessel in order to position the guidewire tip and a location a surgeon desires to treat. 
         [0006]    Conventional guidewire manipulation methods often involve applying torque to the guidewire to aid its passage through tortuous and clogged vessels. Typically, spinning the guidewire in one&#39;s fingertips creates torque to assist in manipulating the guidewire through an obstructed and/or difficult passageway. This technique is also known as “helicoptering”, alluding to the spinning blades of a helicopter. 
         [0007]    However, applying torque is difficult since surgical guidewires have an extremely small diameter and typically have a low friction surface to promote passage through a vessel. Additionally, the gloves of a surgeon or often coated with blood or saline solution, further increasing the slickness of a guidewire. In this respect, helicoptering and similar maneuvers can be time-consuming and inefficient. This inefficiency not only frustrates surgeons, but also increases procedure completion time and, therefore, increases procedure costs. 
         [0008]    Furthermore, in instances where an obstruction is encountered within a vessel, a surgeon generally applies axial motion in an oscillatory manner to drive the guidewire through or past the obstruction. During surgery, an endovascular surgeon may encounter an occlusion that is chronic and/or calcified. Such occlusions have a hard shell with a consistency much like plaster. These forms of obstructions can be difficult and sometimes impossible to penetrate using manual manipulation of a guidewire. Consequently, a procedure may be abandoned when such difficult obstructions are encountered. 
         [0009]    Therefore, there is a need in the art for a method and apparatus for manipulating a guidewire. 
       SUMMARY OF THE INVENTION 
       [0010]    Embodiments of the present invention generally comprise a method and apparatus for manipulating a surgical guidewire. Specifically, the apparatus comprises a chuck for selectively coupling motive force to a surgical guidewire and an actuator, coupled to the chuck, for imparting an axial motive force to the chuck. Embodiments of the invention further comprise a method of using the apparatus. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. 
           [0012]      FIG. 1  illustrates a view of one embodiment of a guidewire manipulation device being used on a patient according to an embodiment of the present invention; 
           [0013]      FIG. 2  depicts a schematic block diagram of a guidewire manipulation device according to an embodiment of the present invention; 
           [0014]      FIG. 3  depicts a vertical cross-sectional view of a guidewire manipulation device according to an embodiment of the present invention; 
           [0015]      FIG. 4  depicts a portion of an actuator used in the guidewire manipulation device of  FIG. 3 ; 
           [0016]      FIG. 5  depicts a perspective view of a hub of a chuck that imparts axial motive force to a guidewire when using the guidewire manipulation divisive  FIG. 3 : 
           [0017]      FIG. 6  depicts a block diagram of a controller for a guidewire manipulation device in accordance with an embodiment of the present invention; 
           [0018]      FIG. 7  depicts a vertical cross-sectional view of alternative embodiment of the guidewire manipulation device; 
           [0019]      FIG. 8  depicts a partial perspective view of a portion of a guidewire drive assembly for the guidewire manipulation device of  FIG. 7 ; 
           [0020]      FIG. 9  depicts a cross-sectional view of a portion of the housing for the guidewire manipulation device of  FIG. 7 ; 
           [0021]      FIG. 10  depicts a vertical cross-sectional view of the guidewire manipulation device of  FIG. 7  having the actuator engaged to apply axial motive force to the guidewire in accordance with one embodiment of the invention; and 
           [0022]      FIG. 11  depicts a partial, vertical cross-sectional view of another embodiment of a guidewire manipulation device for imparting axial motive force to a guidewire. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    Embodiments of the present invention comprise a method and apparatus for manipulating a surgical guidewire. The method and apparatus are embodied in a guidewire manipulation device for selectively imparting motive force (rotational end/or axial (near) motion) to a surgical guidewire. In use, such a guidewire manipulation device is selectively tacked to a surgical guidewire and is activated to impart motive force to maneuver the guidewire to a desired location during an endovascular procedure. The motive force applied to the guidewire is selectively rotational or axial to facilitate moving the surgical guidewire through a vessel and/or penetrating occlusions. 
         [0024]      FIG. 1  illustrates a view of a guidewire manipulation device  100  being used on a patient  110  according to one embodiment of the present invention. In one embodiment, the guidewire manipulation device  100  is a handheld device capable of fitting in the palm of a user&#39;s hand and being operated using one hand. In one embodiment, the guidewire manipulation device  100  is advanced over a surgical guidewire  102 , i.e., the guidewire  102  passes through a longitudinally oriented passage in the device  100 ). During an endovascular procedure, the guidewire  102  is introduced into a vessel  106  (e.g., a femoral artery) of the patient  110 . The guidewire manipulation device  100  is selectively locked to the guidewire  102 . As the guidewire is advanced into the patient, the user operates the manipulation device  100  to impart motive force (rotational and/or axial motion) to the guidewire  102 , as appropriate. 
         [0025]    For example, as a distal end  108  of the guidewire  102  reaches an angled or curved region of the vessel  106 , the user locks the manipulation device  100  to the guidewire and imparts rotational motive force to the guidewire  102  (e.g., in a counterclockwise direction indicated by arrow  104 ), thereby causing the distill end  108  of the guidewire  102  to more easily advance through the angled or curved region of the vessel  106 . Once advanced past the region, the device  100  is unlocked from the guidewire and the guidewire can be further advanced through the vessel. In another example, the distal end  108  of the guidewire  102  reaches an obstruction (e.g., an embolism) but is unable to pass the obstruction. The user then locks the guidewire manipulation device  100  to the guidewire  102  and imparts a vibratory motion (e.g., rapidly oscillating between clockwise and counterclockwise rotation). Such motion causes the distal end of the guidewire  102  to pass through the obstruction. In another example, when the distal end of the guidewire  102  reaches an obstruction, the user locks the guidewire manipulation device  102  to the guidewire  102  and imparts an axial motion (e.g., a linear movement of the guidewire  102 ) to create a jackhammer effect. In another embodiment, the user may lock the device  100  to the guidewire  102  and simultaneously impart both rotational and axial motion to the guidewire  102 . In another embodiment of the invention, a sequence of predefined guidewire manipulations (i.e., a pattern) may be produced using a computer program for controlling the motion as described in detail below. Various motive patterns to be selectively used in various surgical situations can be selected from memory and applied to the guidewire. 
         [0026]      FIG. 2  depicts a schematic block diagram of one embodiment of a guidewire manipulation device  100 . The guidewire manipulation device  100  defines an axially longitudinal passage  204  through which the guidewire  102  is threaded during use. The guidewire manipulation device  100  comprises a housing  200 , an actuator  206 , and a chuck  202 . The chuck  202  comprises a guidewire locking mechanism  208 . During use, the chuck  202  is locked to the guidewire  102  using the looking mechanism  208 . Once locked, the actuator selectively imparts motive force (rotational motion and/or axial motion) to the guidewire  102 . 
         [0027]      FIG. 3  depicts a vertical cross-sectional view of one embodiment of a guidewire manipulation device  100 . In this embodiment, the actuator  206  of  FIG. 2  is divided into a rotary actuator  206 A and an axial actuator  206 B such that the device may selectively apply to the guidewire: no motive force, rotary motive force or rotary and axial motive force. 
         [0028]    Device  100  comprises a housing  200  typically formed into halves that are glued, screwed, or otherwise affixed to each other to form an enclosure. Within the housing  200  are defined slots  350  wherein are retained bushings  302 A and  302 B. The bushings  302 A and  302 B support an axle  300 . The axle  300  defines the passage  204  extending axially through the axle  300 . When in use, the guidewire  102  is threaded through the passage  204 . 
         [0029]    The rotary actuator  206 A comprises the axle  300 , a motor  328 , a drive assembly  326 , a controller  330 , and a control switch  332 . The drive assembly  326  couples rotational motion of the motor  328  to the axle  300  using a plurality of gears, further described with respect to  FIG. 4  below, in one embodiment of the invention, the controller  330  is simply one or more batteries that are coupled to the motor  328  via the control switch  332 . In such an embodiment, the control switch  332  may simply apply a voltage from the one or more batteries to the motor  328  to cause the motor  328  to rotate. In its simplest form, the control switch  332  is a simple single-pole, single-throw (SPST), momentary contact switch. In more complex embodiments, the controller  330  comprises a programmable microcontroller as described with respect to  FIG. 6  below. In other embodiments, the switch  332  may apply voltage to cause the motor  328  to selectively rotate clockwise or counterclockwise. The control switch  332  is generally mounted to be exposed to the exterior of the housing  200  and facilitate manipulation by one hand of a user (e.g., a thumb activated push-button or slide switch. 
         [0030]    The axle  300  is coupled to a chuck  202 . In one embodiment, the chuck  202  comprises a coupler  304 , a hub  324  and a wedge  314 . The coupler  304  and the axle  300  have splined mating surfaces  342  for coupling the rotational motion of the axle  300  to the chuck  202 , while allowing the coupler  304  to move in an axial direction. The hub  324  is threaded onto the coupler  304  at surface  312 . The wedge  314  is located in a window  352  defined by the coupler  304 . The hub  324  retains the wedge  314  within the window  352 . In a disengaged (unlocked) position, the hub  324  does not impart pressure to the wedge  314  thereby allowing the guidewire  102  to slide freely beneath the wedge  314  and through the passage  204 . To lock the guidewire into the lock mechanism  208 , the hub  324  is rotated relative to the coupler  304  such that the angled surface  316  of the hub  324  interacts with the top surface  318  of the wedge  314 . As the hub  324  is moved relative to the coupler  304  via the mating threaded surfaces  312 , the wedge  314  is forced against the guidewire  102 . Consequently, the guidewire is captured between the wedge  314  and the coupler  304  and thereby locked into the chuck  202 . Once locked, any motion of the chuck  202  is imparted as motive force to the guidewire  102 . 
         [0031]    Other embodiments of the invention utilize other forms of chucks. In a broad sense, any mechanism that can be used to selectively lock the guidewire to a source of motive force may be used. Other forms of chucks having multiple jaws or compressive slotted cylinders are applicable. 
         [0032]    The coupler  304  comprises a spring seat  354  supporting a first end of a spring  306 . The second end of spring  306  rests against a flange  322  that extends from the inner surface of the housing  200 . The spring  306  is one embodiment of a resilient member that biases the coupler  304  inwardly toward the axle  300 . The coupler  304  further comprises a flange  320  that extends radially from the outer surface of the coupler  304 . The flange  320  is positioned along the coupler  304  to limit the amount of axial movement that can be imparted to the chuck  202 . The flange  320  abuts the housing flange  322 . As such, the spring  306  biases the coupler  304  to maintain contact between the flange  320  and the flange  322 . 
         [0033]    To impart axial motion to the chuck  202 , the bottom surface  356  of the hub  324  is dimpled. The surface  356  interacts with a protrusion  336  extending from the exterior surface of the housing  200  proximate the surface  356  of the hub  324 . Depending on the position of the hub  324  relative to the coupler  304 , the spring  306  insurers that the protrusion  336  interacts with the dimpled surface  356 . Upon locking the chuck  202  to the guidewire  102  and imparting rotation to the chuck  202 , the guidewire  102  moves in an axial direction as indicated by arrow  358 . To disengage the axial motive force, the hub  324  is rotated relative to the coupler  304  along the threads  312  to decouple the protrusion  336  from the surface  356 . In this manner, the locking mechanism  208  retains the guidewire  102  such that rotational motion of the axle  300  is imparted to the guidewire  102  without imparting axial motion. In this embodiment, the axial motion actuator  206 B comprises the hub  324 , spring  306 , coupler  304  and the housing  200 . 
         [0034]      FIG. 4  depicts a cross sectional view of the drive assembly  328  of the rotary actuator  206 A taken along line  4 - 4  of  FIG. 3  in accordance with one embodiment of the invention. The drive assembly  326  comprises a motor gear  400 , an intermediary gear  402  and an axle gear  404 . The motor  328  of  FIG. 3  is coupled to the motor gear  400  to impart rotational motion to the motor gear. In one embodiment, the axle gear  404  is formed as an integral part of this surface of the axle  300  of  FIG. 3 . The intermediary gear  402  is designed to provide a gear ratio between the motor gear  400  and axle gear  404 . The diameters and the number of teeth of each gear is considered to be a design choice that will do fine the speed of rotational motion of the guidewire as well as the oscillatory speed of the axial motion. 
         [0035]    In other embodiments, the motor  328  of  FIG. 3  may be coupled to the axle via other forms of drive assemblies, e.g., direct drive, worm gear, and/or the like. The specific motor and drive assembly characteristics are considered a design choice to develop specific guidewire rotation speed and torque. In some embodiments, the drive assembly may be adjustable to facilitate creating specific speed and torque profiles or adjustments. One form of adjustments may be facilitated by the use of a stepper motor that can be controlled with a pulse width modulated signal produced by the controller, as discussed below. 
         [0036]    An alternative embodiment for imparting rotary motive force in selectable directions uses a gear train comprising two larger diameter spur gears mounted on a common shaft that is driven constantly in one direction by an electric motor. Each of the two spur gears has a section of its teeth, something over ½ its total number, removed. The removed sections of teeth are positioned such that only one or the other of two additional smaller spur gears, each located to be driven by one of these common shaft gears, will be driven at a time. The two smaller spur gears are then used one at a time to drive the gear on the axle, but the positioning of one additional gear between just one of these driving gears and the axle gear results in the rotational direction of the axle being reversed when that set is driving the axle gear. 
         [0037]    Another embodiment, if only forward and reversing is required without a near constant rotational speed in either direction, has the spur gear on the axle driven by a pivoted ¼ pie shaped plate. The toothed curved section opposite the pivot near the tip would have the correct pitch radius to mesh with the axle spur gear. This pivoted gear section plate would have, running upwards from its pivot, a slot in its face in which a pin, mounted off-center an a disc, could slide up and down freely. As an electric motor turns this disc in a constant direction, it would cause the pivoted plate to wobble back and forth so that its gear section drives the axle spur gear in one direction and then in the reverse direction. 
         [0038]      FIG. 5  depicts a perspective view of the hub  324  in accordance with one embodiment of the invention. The hub  324  comprises a surface  356  having a plurality of dimples  504  and spaces  502  between the dimples  504 . The hub  324  further comprises a threaded interior surface  312 . The threaded interior surface  312  is adapted to interact with a threaded exterior surface of the couple or  304  to adjust the position of the hub relative to the coupler  304  and the wedge  314 . The dimples  504  and the spaces between the dimples  502  are adapted to interact with the protrusion  336  to impart axial motion to the chuck  202 . The spacing of the dimples and the speed of the motor control the oscillation rate of the axial motion. Furthermore, the depth of the dimples  504  relative to the spaces  504  on the surface  356  controls the travel distance of the axial motion. 
         [0039]      FIG. 6  depicts a block diagram of the controller  330  in accordance with one embodiment of the present invention. The controller  330  comprises a microcontroller  600 , support circuits  602 , memory  604  and a power supply  606 . The microcontroller  600  may be one or more of many commercially available microcontrollers, microprocessors, application specific integrated circuits (ASIC), and the like. The support circuits  602  comprise well known circuits that facilitate the operation of the microcontroller  600  including, but not limited to, clock circuits, cache, power supplies, input/output circuits, indicators, sensors, and/or the like. In one embodiment, the power supply  606  comprises one or more batteries. In other embodiments, the power supply  606  may comprise in AC to DC converter to allow the guidewire manipulation device to be plugged into a wall socket. In further embodiments, the power supply  606  may comprise one or more batteries and a charging circuit for the batteries may be inductively coupled to a base charger. 
         [0040]    The memory  604  may be any form of memory device used to store digital instructions for the microcontroller  600  as well as data. In one embodiment, the memory  604  is random access memory or read only memory comprising control code  608  (e.g., computer readable instructions) that are used to control the actuator  206  to impart motion to the guidewire. The programs utilized by the microcontroller  600  to control the actuator  206  are generally controlled by the control switch  332  and/or another input device. 
         [0041]    In one embodiment of the invention, the motor  328  is a stepper motor that is controlled using, for example, a pulse width modulated signal produced by the controller  332  to impart specific torque and/or speed profiles to the motor  328 . In some embodiments, predefined programs can be generated and selected through manipulation of the switch  332  to enable a user to overcome specific types of obstructions within the path of the guidewire. For example, if a surgeon encounters a specific type of embolism, a specific program defining the motion of the guidewire to overcome the obstruction can be selected and implemented. Various programs can be generated through empirical study of guidewire utilization in endovascular procedures. To select a particular motion pattern, the switch may be a slide switch having a plurality of selectable positions, where each position corresponds to a different motion pattern. 
         [0042]      FIG. 7  depicts a vertical cross-sectional view of a guidewire manipulation device  650  according to an alternative embodiment of the invention. In this embodiment, the use of axial motion is selected through manipulation of a mechanical switch  702 . As with the prior embodiment, this embodiment selectively imparts to a guidewire: no motive force, rotary motive force, or rotary and axial motive force. The device  650  comprises a rotational actuator  206 A as described above with respect to  FIG. 3 . In this embodiment, a coupler  700  comprises a spring seat  750 , a dimpled flange  710  and a switch stop  752 . A slidable switch  702  comprises an extension  704  that interacts with a switch seat  752 . They switch seat  752  and the spring seat  754  define a space  706  that captures the switch extension  704 . Manipulation of the switch  702  causes the coupler  700  to move axially along the surface that mates with the axle  300 . A spring  708  is positioned between the spring seat  705  and the housing flange  322 . The spring  708  biases the coupler inwardly toward the axle  300 . The dimpled flange  702  radially extends from the coupler  700 . One surface of the dimpled flange abuts the housing flange  322  to limit the distance the coupler  700  moves in an axial direction. The dimpled flange  710  has a surface aligned with a dimpled surface  712  of the housing  200 . When the guidewire is locked to the chuck  202  and the rotational actuator  206 A is activated, the guidewire  102  rotates without any axial movement. As described further with respect to  FIG. 10  below, when the switch  702  is moved forward to cause the dimpled surface of flange  710  to engage the dimpled surface  712 , the guidewire  102  axial motive force is imparted to the guidewire  102 . 
         [0043]      FIG. 8  depicts a partial perspective view of the coupler  700  in accordance with one embodiment of the invention. The coupler  700  has an aperture  806  through which the guidewire is threaded. The dimpled flange  710  comprises a radially extending flange  802  having a plurality of dimples  800  formed in the surface. In one embodiment, the dimples are formed as a sequence of wedges. In other embodiments, to cause axial motion of the chuck when the coupler  700  is rotated, the surface of the flange  802  needs to be varied such that interaction with a corresponding surface causes axial movement of the coupler  700 . 
         [0044]      FIG. 9  depicts a cross-sectional view of the housing  200  taken along line  9 - 9  in  FIG. 7 . In one embodiment, the surface  712  comprises corresponding protrusions shaped to interact with the dimples in surface  800  of the coupler  700 . In another embodiment, the surface  712  may comprise complementary wedges  900  to the surface  800  of the coupler  700 . The shape of the wedges defines, in part, the distance travelled, the rate of acceleration of the guidewire, and the speed of the guidewire oscillation. 
         [0045]      FIG. 10  depicts an embodiment of the guidewire manipulation device  650  of  FIG. 7  where the dimpled flange  710  has been engaged the protrusion surface  712 . In this manner, the switch  702  has moved the coupler  700  forward to facilitate engagement of the surfaces  710  and  712 . When the chuck  202  locks to the guidewire  102  and the rotary actuator is activated, the guidewire  102  rotates as shown in arrow  1002  and axially oscillates as represented by arrow  1000 . 
         [0046]      FIG. 11  depicts a vertical cross-sectional view of a portion of a guidewire manipulation device  1100 . Device  1100  comprises an axial actuator  206 B that can be selectively utilized without imparting rotational motion of the guidewire. As such, with this embodiment, the device  110  selectively imparts to the guide wire: no motive force, rotary motive force, axial motive force, or axial and rotary motive force. 
         [0047]    In one embodiment, the device  1100  comprises a linear actuator  1116  couple to a shaft of  1114  that interacts with a fulcrum  1112 . The linear actuator  1116  imparts linear motion to one portion of the fulcrum  1112 . The fulcrum is mounted upon a pivot point  1120  such that the fulcrum  1112  rotates about the pivot point  1120  as a linear motive force is applied to the fulcrum  1112 . A second end of the fulcrum  1112  interacts with a coupler  1104 . The coupler  1104 , as with prior embodiments, has a splined surface that interacts with the axle  300  to impart rotational motion to the coupler, as needed. The coupler  1104  comprises a spring seat  1108 . A spring  1106  is positioned between the housing  1102  and the spring seat  1108  to bias the coupler  1104  toward the axle  300 . The fulcrum  1102  couples to the spring seat  1108  such that motion of the fulcrum  1102  axially moves the coupler  1104 . In this manner, without any rotational motion the linear actuator  1116  imparts axial motion to the coupler and to guidewire  102  locked in the chuck  202 . 
         [0048]    In one embodiment, the linear actuator  1116  may be a solenoid, piezoelectric actuator, linear motor, rotary motor and ball screw or rack/pinion, and/or the like. In another embodiment, a hammer-drill type assembly may be used to impart axial force to the guidewire. 
         [0049]    The controller  330  in a manner similar to that described for controlling the motor  328  of  FIG. 3  may control the linear actuator  1116 . 
         [0050]    While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.