Abstract:
A surgical instrument is operable to deploy an anastomotic ring device. The instrument comprises a ring deployment mechanism configured to receive and deploy the anastomotic ring through an actuating force. The instrument further comprises an electroactive polymer that is configured to receive voltage from a power source. The electroactive polymer is configured to convert the voltage to a mechanical actuating force. The electroactive polymer is further configured to apply the actuating force to the ring deployment mechanism to deploy the anastomotic ring.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates, in general, to surgery and, more particularly, to a device for performing a surgical procedure on the digestive system.  
       BACKGROUND OF THE INVENTION  
       [0002]     The percentage of the world population suffering from morbid obesity is steadily increasing. Severely obese persons may be susceptible to increased risk of heart disease, stroke, diabetes, pulmonary disease, and accidents. Because of the effects of morbid obesity on the life of the patient, methods of treating morbid obesity have been the subject of intense research.  
         [0003]     One known method for treating morbid obesity includes the use of anastomotic rings. Devices for applying anastomotic rings are known in the art. Devices of this nature are commonly adapted to insert a compressed anastomotic ring to an anastomotic opening formed between proximate gastrointestinal tissue walls. These applier devices may utilize a ring deployment mechanism comprising an expansion element that is actuated once the compressed ring is placed in the anastomotic opening, causing the anastomotic ring to expand from its compressed, cylindrically-shaped position to an actuated, hollow rivet-shaped position.  
         [0004]     Many conventional applier devices require that an actuation force be transmitted from the operating handle to the distal ring deployment mechanism. While this force is generally relatively small, even a low force may be prohibitive when it must be transmitted to the end of a long flexible or detached structure. Consequently, it may be desirable to have an anastomotic ring applier device in which an actuation force capable of deploying an anastomotic ring is generated at a distal portion of the device and is independent of the length of the shaft connecting the operating handle to the ring deployment mechanism.  
       BRIEF SUMMARY OF THE INVENTION  
       [0005]     Various embodiments of the invention provide an anastomotic ring applier device that allows the surgeon to cause an actuation force to generate at a distal portion of the applier device in order to actuate a ring deployment mechanism to deploy an anastomotic ring.  
         [0006]     In one embodiment, an anastomotic ring applier device comprises a ring deployment mechanism configured to receive and deploy an anastomotic ring. The device further comprises a power source capable of generating a voltage. The device also comprises an electroactive polymer adapted to receive voltage and convert it into a mechanical actuation force. The electroactive polymer is further adapted to apply the mechanical actuation force to the ring deployment mechanism in order to deploy the ring. This device provides a means of generating a mechanical actuation force capable of deploying an anastomotic ring that is not necessarily dependent on transmitting a mechanical force over a long distance.  
         [0007]     In another embodiment, an instrument comprises a handle including an actuating member for receiving operator input. The device further comprises an electroactive polymer that is adapted to receive operator input in the form of voltage. The electroactive polymer is further be adapted to convert voltage to a mechanical actuation force, which it may apply to a ring deployment mechanism to apply an anastomotic ring. In this embodiment, the device allows the operator to apply a negligible force to an actuating member to generate an electrical current to produce the necessary mechanical actuation force at the ring deployment mechanism.  
         [0008]     In yet another embodiment, a device comprises a handle connected to a proximal portion of an elongated shaft. The device further comprises a ring deployment mechanism at a distal end of the shaft. The device includes a power source adapted to generate a voltage, which may be received by an electroactive polymer. The electroactive polymer is adapted to convert the voltage to a mechanical actuation force, which it may apply to the ring deployment mechanism to apply an anastomotic ring. In this embodiment, the device may advantageously avoid the need to transmit a mechanical actuation force along the entire length of an elongated shaft.  
         [0009]     In still another embodiment, the device comprises a handle and an elongated shaft comprising a proximal portion and a distal portion, wherein the proximal portion of the shaft is connected to the handle. The device further comprises a ring deployment mechanism at a distal portion of the shaft. The ring deployment mechanism comprises a proximal portion and a distal portion. A first electroactive polymer is connected to the proximal portion of the deployment mechanism, and is further adapted to receive voltage from the power source and convert it to a mechanical actuation force that may be applied to the proximal portion of the deployment mechanism to deploy a proximal portion of the anastomotic ring. Similarly, a second electroactive polymer is connected to the distal portion of the deployment mechanism, and is further adapted to receive voltage from the power source and convert it to a mechanical actuation force that may be applied to the distal portion of the deployment mechanism to deploy a distal portion of the anastomotic ring. In this embodiment, the device may advantageously generate separate mechanical actuation forces to deploy two portions of an anastomotic ring without requiring that mechanical force be necessarily transmitted along the length of a shaft. 
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0010]     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate versions of the invention, and, together with the general description of the invention given above, and the detailed description of the versions given below, serve to explain the principles of the present invention.  
         [0011]      FIG. 1  is a perspective view of an anastomotic ring applier device.  
         [0012]      FIG. 2  is a partial perspective view of the distal portion of an anastomotic ring applier device holding an anastomotic ring in an unactuated position.  
         [0013]      FIG. 3  is a partial perspective view of the anastomotic ring applier device of  FIG. 2  holding an anastomotic ring an actuated position.  
         [0014]      FIG. 4  is a frontal view of an actuated anastomotic ring.  
         [0015]      FIG. 5  is a perspective view of the device of  FIG. 1  with a distal portion of a ring deployment mechanism in an actuated position.  
         [0016]      FIG. 6  is a perspective view of the device of  FIG. 1  shown with both a distal and a proximal portion of a ring deployment mechanism in an actuated position.  
         [0017]      FIG. 7  is an exploded view of the ring deployment mechanism of the device of  FIG. 1 .  
         [0018]      FIG. 8  is a cross-sectional exploded view of the handle of the device of  FIG. 1 , omitting a left half of the handle.  
         [0019]      FIG. 9  is a cross-sectional view of the ring deployment mechanism of  FIG. 4  in an unactuated position.  
         [0020]      FIG. 10  is a cross-sectional view of the ring deployment mechanism of  FIG. 4  with the distal portion in an actuated position.  
         [0021]      FIG. 11  is a cross-sectional view of the ring deployment mechanism of  FIG. 4  with both the distal and the proximal portions in an actuated position.  
         [0022]      FIG. 12  is a cross-sectional view of a shaft portion of an anastomotic ring applier device consistent with the present invention.  
         [0023]      FIG. 13  is a cross-sectional view of the handle of the device of  FIG. 1 , omitting a left half of the handle. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]     Turning to the Drawings, wherein like numerals denote like components throughout the several views,  FIG. 1  depicts an applier  10  that is operable to deploy and actuate an anastomotic ring device (not pictured in  FIG. 1 ) from a generally cylindrical shape to one having properties of a hollow rivet, or ring, capable of forming an anastomotic attachment at an anastomosis target site, such as in a bariatric gastric bypass of a morbidly obese patient.  FIG. 2  depicts another applier  12 . It will be appreciated that appliers  10 ,  12  may be used in a variety of ways, including but not limited to laparoscopically or endoscopically. Applier  12  is shown in  FIG. 2  with an anastomotic ring  14  on a deployment mechanism  16 . In  FIG. 2 , anastomotic ring  14  is shown in the compressed, cylindrically-shaped position. In  FIG. 3 , deployment mechanism  16  of applier  12  has moved anastomotic ring  14  to the actuated, hollow rivet-shaped position.  FIG. 4  is a close-up view of anastomotic ring  14  in the actuated position. Anastomotic ring  14  may comprise a shape memory effect (SME) material, such as nitinol by way of example only, that further assists in actuation to an engaging hollow rivet shape. Other suitable anastomotic ring  14  materials will be apparent to those of ordinary skill in the art. An exemplary anastomotic ring  14  is described in detail in U.S. Patent Application Publ. No. US  2003 / 0032967  to Park et al.  
         [0025]     It will be appreciated that the terms “proximal” and “distal” are used herein with reference to a clinician gripping a handle of applier  10 . It will be further appreciated that for convenience and clarity, spatial terms such as “right”, “left”, “vertical” and “horizontal” are used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and absolute. In addition, aspects of the invention have application to surgical procedures performed endoscopically and laparoscopically, as well as an open procedure or other procedures. Use herein of one of these or similar terms should not be construed to limit the present invention for use in only one category of surgical procedure.  
         [0026]     Referring again to  FIG. 1 , applier  10  of the present example comprises a handle  18  connected to an elongated shaft  20  having a proximal end  22  and a distal end  24 . As shown in  FIG. 1 , elongated shaft  20  is flexible, either along its entire length or at one or more joints. Of course, shaft  20  may alternatively be rigid, resilient, malleable, or have other properties. Distal end  24  of shaft  20  comprises a ring deployment mechanism  26 . Deployment mechanism  26  may be actuated by a button or lever located on handle  18 . As shown in  FIG. 1 , in one embodiment, handle  18  comprises a pair of actuator buttons  28 ,  30 . The functioning of actuator buttons  28 ,  30  will be described below. Ring deployment mechanism  26  is located proximal of a tip  32 .  
         [0027]     In the present example, ring deployment mechanism  26  comprises a plurality of proximal fingers  34  and a plurality of distal fingers  36 . Both proximal fingers  34  and distal fingers  36  are each in a double-hinged relationship with a stationary mid-ring  38  of ring deployment mechanism  26 . Proximal fingers  34  are adapted to slide toward mid-ring  38  in response to actuation of actuator button  28 , causing fingers  34  to actuate outwardly from shaft  20  ( FIG. 6 ). Likewise, distal fingers  36  are adapted to slide toward mid-ring  38  in response to actuation of actuator button  30 , causing fingers  36  to actuate outwardly from shaft  20  ( FIG. 5 ). In this manner, an anastomotic ring may be deployed from the compressed, cylindrical position to the actuated, hollow rivet-forming position, as shown in  FIG. 3 . Fingers  34 ,  36  are configured to hold the anastomotic ring by engaging petals  51  prior to and during deployment of the anastomotic ring, and release petals  51  upon deployment of the anastomotic ring.  
         [0028]     Referring to  FIG. 7 , an embodiment of ring deployment mechanism  26  is shown in an exploded view. As described above, ring deployment mechanism  26  comprises proximal fingers  34 . Proximal fingers  34  are connected to an outer tube  40  comprising a flange  42 . Mid-ring  38  is connected to a ground tube  44  comprising a flange  46 . Distal fingers  36  are connected to an inner tube  48  comprising a flange  50 . Ground tube  44  is grounded to shaft  20 , as shown in  FIG. 6 , and is therefore stationary. Other suitable configurations for ring deployment mechanism  26  will be apparent to those of ordinary skill in the art.  
         [0029]     In the present example, ring deployment mechanism  26  further comprises an electroactive polymer (EAP)  52  comprising a proximal portion  54  and a distal portion  56 . Proximal portion  54  of EAP  52  is attached to flange  46  of ground tube  44 . Distal portion  56  is attached to flange  42  of outer tube  40 . As shown in  FIG. 7 , applier  10  comprises a pair of opposing EAPs  52 . An EAP  58  comprising a proximal portion  60  and a distal portion  62  is further included in ring deployment mechanism  26 . Proximal portion  60  is attached to flange  50  of inner tube  48  and distal portion  62  is attached to flange  46  of ground tube  44 . As shown in  FIG. 7 , applier  10  comprises a pair of such EAPs  58 . EAPs may be of any suitable type, including but not limited to electronic EAPs or ionic EAPs.  
         [0030]     In the present example, EAPs  52 ,  58  comprise thin conductive sheets laminated onto a polymer core. In one embodiment, the conductive sheets comprise a carbon fiber composite. When a small voltage is induced across the electrodes of EAPs  52 ,  58 , the electrodes are drawn together, resulting in a deformation of the polymer substrate. Deformation of the substrate causes the polymer to expand in one direction and to contract in the perpendicular direction. The voltage necessary to cause deformation of the polymer substrate may be relatively small. In one embodiment, the voltage induced across the electrodes of the EAPs may be between approximately 1.5 volts to approximately 3 volts. Alternatively, EAPs may be configured to be responsive to other voltages. It is also possible to stack EAP sheets in order to achieve an additive effect in generating force. In one embodiment, EAP sheets are very thin in order to optimize output force. By way of example only, the thickness of the EAP sheets may be approximately 20 microns, resulting in an available power density of approximately 200 kg/cm 2 , or about 100 times the power density of human muscle, and a maximum tensile strength of 100 MPa (or 60 MPa using engineering plastics). The EAPs may be capable of achieving a maximum strain of 40% at a maximum strain rate of 8% per second. It will be appreciated, however, that the foregoing EAP properties are merely exemplary and thus optional, and a variety of other EAP configurations may be used, as well as EAPs having a variety of other properties.  
         [0031]      FIG. 9  shows proximal and distal fingers  34 ,  36  in an unactuated state. By attaching EAP  58  to slideable inner tube  48  and stationary ground tube  44 , EAP  58  of the present example is adapted to expand in response to voltage and thereby draw distal fingers  36  proximally and outwardly ( FIG. 10 ), thereby deploying a distal portion of an anastomotic ring. Similarly, by fixedly attaching EAP  52  to ground tube  44  and outer tube  40 , EAP  52  is adapted to expand longitudinally in response to induction of voltage and thereby push proximal fingers  34  distally and outwardly ( FIG. 11 ), deploying a proximal portion of an anastomotic ring.  
         [0032]     As shown in  FIG. 8 , handle  18  houses a power source  64  ( FIG. 12 ). Alternatively, an external power source may be utilized to induce a voltage across EAPs  52 ,  58 . In the present example, first actuator button  28  is moveable from a first, non-actuated position to a second, actuated position, thereby causing power source  64  to induce a voltage across EAP  52 , causing the polymer substrate to expand and push proximal fingers  34  distally to deploy a proximal portion of an anastomotic ring. Second actuator button  30  is moveable from a first, non-actuated position to a second, actuated position, thereby causing power source  64  to induce a voltage across EAP  58 , causing the polymer substrate to expand and draw distal fingers  36  proximally to deploy a distal portion of an anastomotic ring. Alternatively, the relationship between actuator buttons  28 ,  30  and fingers  34 ,  36  may be reversed, such that first actuator button  28  controls distal fingers  36  and second actuator button  30  controls proximal fingers  34 . In addition, any suitable alternative to actuator buttons  28 ,  30  may be used. Other variations will be apparent to those of ordinary skill in the art.  
         [0033]     In the present example, when first and second actuator buttons  28 ,  34  are in the unactuated position, applier  10  is configured such that no voltage is induced across EAPs  52 ,  58 . In the present example, voltage is conducted to EAPs  52 ,  58  from power source  64  via conductive wires  66 . Each EAP  52 ,  58  is adapted to receive a positive and negative lead  66  from power source  64 .  
         [0034]     While the foregoing examples include EAPs being connected to ground tube  44 , inner tube  48 , and outer tube  40 , it will be appreciated that EAPs may be used in a device such as applier  10  to deploy an anastomotic ring in a variety of other ways and configurations. By way of example only, instead of being connected to tubes  44 ,  48 , and  40 , EAPs may be connected to one or more fingers  34 ,  32  to accomplish actuation of the fingers  34 ,  32 . Alternatively, at least a portion of one or more fingers  34 ,  32  may comprise EAP material. For instance, at least a portion of at least one side of each finger  34 ,  32  may comprise EAP material. Thus, fingers  34 ,  32  may be configured with EAP such that they operate in a manner similar to a venus flytrap. In other words, fingers  34 ,  32  may open to deploy an anastomotic ring by having the surface area of one side of a finger/leaf increase relative the surface area of the other side of the finger/leaf. By way of example only, at least a portion of fingers  34 ,  32  may comprise an EAP configured to expand in response to an applied voltage, thereby causing fingers  34 ,  32  to expand for ring deployment. Similarly, at least a portion of fingers  34 ,  32  may comprise an EAP configured to shrink or retract in response to an applied voltage (or in the absence of an applied voltage), thereby causing fingers  34 ,  32  to retract or close for removal of applier  10 . Alternatively, EAP may be configured such that it causes fingers  34 ,  32  to retract or close when polarity of the voltage is reversed. In such an embodiment, the applier  10  may include a switch or other means for switching polarity.  
         [0035]     Alternatively, fingers  34 ,  32  may comprise an EAP and a resilient material, such that fingers  34 ,  32  open in response to voltage being applied to EAP, and fingers  34 ,  32  close at the urging of resilient material when voltage is removed. In yet another embodiment, each finger  34 ,  32  is hingedly connected to a linkage comprising EAP. Other suitable ways in which fingers  34 ,  32  may be configured with EAP materials will be apparent to those of ordinary skill in the art.  
         [0036]     It will also be appreciated that, where EAP is positioned in ring deployment mechanism  26  at a location distally beyond shaft  20 , one or more of tubes  44 ,  48 , or  40  may be obsolete. In one embodiment, where EAP is positioned in ring deployment mechanism  26  at a location distally beyond shaft  20 , tubes  44 ,  48 , or  40  are absent from shaft  20 , and shaft  20  houses conductive wires  66  only. Alternatively, EAP may be used both within shaft  20  and distally beyond shaft  20 . Still other suitable configurations will be apparent to those of ordinary skill in the art.  
         [0037]     Having shown and described various embodiments and concepts of the invention, further adaptations of the methods and systems described herein can be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the invention. Several of such potential alternatives, modifications, and variations have been mentioned, and others will be apparent to those skilled in the art in light of the foregoing teachings. Accordingly, the invention is intended to embrace all such alternatives, modifications and variations as may fall within the spirit and scope of the appended claims and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings. Additional advantages may readily appear to those skilled in the art.