Patent Publication Number: US-2018049738-A1

Title: Articulating medical device

Description:
FIELD AND BACKGROUND OF THE INVENTION 
     The present invention relates to a device for intrabody use and, more particularly, to an articulating device suitable for mechanically securing implants, such as hernia meshes to intrabody tissue as well as an articulating shaft for use with a medical device. 
     Suturing is a mainstay of surgical repair, however, manipulation of a suture needle as well as access to the suturing location can be difficult in minimally invasive surgery due to the limited anatomical space around the target tissues. 
     Due to these limitations of suturing, devices developed to deliver staples, fasteners (e.g. tacks), anchors and tissue adhesives have gained wide spread acceptance in minimally invasive surgery. Such devices enable rapid and accurate ligation of tissue and/or fixation of implants to tissue under the anatomical space constraints imposed by minimally invasive surgery. 
     One minimally invasive surgical approach that utilizes such a device is hernia repair. 
     A hernia is a protrusion of abdominal content (preperitoneal fat, omentum or abdominal organs) through an abdominal wall defect. 
     Currently, the most frequently used minimally invasive technique involves laparoscopic fixation with transabdominal devices that deliver helical coils (tacks) with a maximal tissue penetration depth of several millimeters. 
     Fixation with tacks is fast and strong and can be rapidly achieved, however, due to anatomical constraints, it can be difficult or impossible to correctly align the tack-delivery head of rigid tackers perpendicular to the mesh-tissue interface and thus the resultant fixation can be less than optimal. 
     Tacker devices with articulating tack delivery heads were developed to traverse this limitation of rigid devices and provide correct positioning of the tacker delivery head and optimal tack fixation. 
     Such devices are described in the patent literature (see, for example, US20130119108; US20120271285 and are commercially available (e.g. Covidien ReliaTack™). 
     Although such devices can be used to select a tack delivery angle (with respect to the mesh-tissue interface), selection can be limited to preset angles which can be suboptimal under some conditions. In addition, the small diameter of the shaft required for minimally invasive delivery and the relatively complex construction of the articulation joint can limit the amount of force applied to the device during angled delivery of the tack. 
     There it would be highly advantageous to have a tissue ligation/fixation device devoid of the above limitations. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention there is provided a medical device comprising: (a) a handle detachably connected to a shaft having a proximal portion attached to a distal portion through an articulation region; (b) an articulation mechanism controllable from the handle and being for controlling an articulation angle of the distal portion, the articulation mechanism including a first gear disposed in the proximal portion and a second gear disposed in the distal portion; and (c) a drive mechanism operable from the handle and being for deploying an implant from a distal end of the distal portion, the drive mechanism including an elongated member having a flexible region traversing the articulation region, wherein the first gear is disposed around the elongated member. 
     According to further features in preferred embodiments of the invention described below, the flexible region of the elongated member traversing the articulation region is configured for accommodating a change in angle of the articulation region. 
     According to still further features in the described preferred embodiments the flexible region is capable of elastically elongating when the distal portion is angled with respect to the proximal portion. 
     According to still further features in the described preferred embodiments the flexible region forms an arc when the distal portion is co-linear with the proximal portion. 
     According to still further features in the described preferred embodiments the handle includes a motor for actuating the drive mechanism. 
     According to still further features in the described preferred embodiments the implant is a tissue anchor. 
     According to still further features in the described preferred embodiments the distal portion of the shaft is detachable from the proximal portion. 
     According to still further features in the described preferred embodiments the drive mechanism further includes an implant driver disposed in the distal portion of the shaft. 
     According to still further features in the described preferred embodiments a distal end of the elongated member engages the implant driver. 
     According to still further features in the described preferred embodiments the implant driver is rotatable via the elongated member. 
     According to still further features in the described preferred embodiments rotation of the implant driver delivers the implant from the distal end of the distal portion. 
     According to still further features in the described preferred embodiments the distal portion of the shaft includes a plurality of implants. 
     According to still further features in the described preferred embodiments the drive mechanism cannot be activatable during activation of the articulation mechanism. 
     According to still further features in the described preferred embodiments the drive mechanism is controllable from the handle via a trigger. 
     According to still further features in the described preferred embodiments activation of the trigger deploys a single implant from the distal end of the distal portion. 
     According to still further features in the described preferred embodiments the drive mechanism is only deployable when the distal portion of the shaft is correctly attached to the proximal portion. 
     According to still further features in the described preferred embodiments the articulation mechanism is controllable from the handle via a roller interface. 
     According to still further features in the described preferred embodiments a position of the roller interface indicates an angle of the distal portion with respect to the proximal portion. 
     According to another aspect of the present invention there is provided a medical device shaft attachable to a handle, the shaft comprising a proximal portion attached to a distal portion through an articulation region having an articulation control mechanism controllable from a proximal portion of the shaft, the articulation mechanism being for controlling an articulation angle of the distal portion of the shaft. 
     According to still further features in the described preferred embodiments the articulation mechanism includes a first gear disposed in the proximal portion and a second gear disposed in the distal portion. 
     According to still further features in the described preferred embodiments the articulation mechanism includes a rod positioned in the proximal portion and being hingedly connected to the distal portion through a lever traversing the articulation region. 
     According to still further features in the described preferred embodiments the articulation control mechanism is manually activatable to set an angle of articulation of the distal portion with respect to the proximal portion. 
     According to still further features in the described preferred embodiments manually activating the articulation control mechanism actuates a switch for disabling functions of a handle attachable to the proximal portion of the shaft. 
     According to still further features in the described preferred embodiments the medical device shaft further comprising a drive mechanism disposed within the shaft, the drive including an elongated member having a flexible region traversing the articulation region, wherein the first gear is disposed around the elongated member. 
     The present invention successfully addresses the shortcomings of the presently known configurations by providing an articulating tissue fastener device that can be used in minimally invasive procedures for repair of tissue such as abdominal tissue. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. 
       In the drawings: 
         FIG. 1  is an isometric view of one embodiment of the present device. 
         FIG. 2  illustrates one embodiment of a handle of the present device. 
         FIGS. 3 a - c    illustrate the internal components of the handle of  FIG. 2 . 
         FIG. 4 a - b    illustrate one embodiments of a shaft of the present device in side ( FIG. 4 a   ) and cross sectional ( FIG. 4 b   ) views. 
         FIGS. 4 c - d    are magnified views of the distal portion ( FIG. 4 c   ) and handle engaging portion ( FIG. 4 d   ) of the shaft shown in  FIG. 4   b.    
         FIGS. 5 a - d    illustrate the articulating region ( FIGS. 5 a , 5 c  and 5 d   ) and handle-coupling portion ( FIG. 5 b   ) of the shaft of the present device. 
         FIGS. 6 a - b    illustrate in greater detail the fastener-carrying cartridge of the distal portion of the shaft shown in  FIG. 4   c.    
         FIGS. 7 a - d    illustrate embodiments of a tissue fastener that can be delivered by the present device. 
         FIGS. 8 a - c    illustrates an embodiment of a shaft articulation mechanism deployable via a slider button.  FIG. 8 b    is a magnified view of the region circled in  FIG. 8 a   .  FIG. 8 c    is a closed up view of the articulating region of this embodiment of the present invention. 
         FIG. 9  illustrates a prototype device constructed in accordance with the teachings of the present invention. 
         FIGS. 10-11  illustrate tack delivery through a tissue model using the device of  FIG. 9  ( FIG. 10 ) and the delivered tack ( FIG. 11 ). 
         FIGS. 12 a - b    illustrate an articulating shaft having a shaft-positioned articulation control mechanism ( FIG. 12 a   ) and the internal components of the articulation control mechanism ( FIG. 12 b   ). 
         FIG. 13  is an image of a prototype articulating shaft having shaft-positioned articulation control mechanism. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is of a tissue ligation/fixation device which can be used to fixate an implant to a tissue. Specifically, the present invention can be used to deliver a tissue fastener to a body tissue at a variety of angles using a minimally invasive approach. 
     Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details set forth in the following description or exemplified by the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. 
     Devices for fixating implants such as meshes to body tissues using minimally invasive approaches are well known in the art. Such devices can include a rigid or articulating delivery shaft. 
     In a previously filed application, the present inventors described one such articulating device which includes a drive mechanism for delivering tissue fasteners and an articulation joint having a laterally displaced articulation arm. 
     While experimenting with several prototypes of an articulation-capable tissue fastener, the present inventors realized that the diameter constraints imposed on the device shaft by the delivery port (5.5 mm or less) and the complexity of the articulation region that supports articulation and enables passage of the fastener drive shaft can result in unwanted deflection of the articulation joint and drive shaft under loads applied during angulation of the delivery head. 
     In order to minimize the effects of such loads, the present inventors devised an articulation joint and fastener drive shaft arrangement that enable delivery head deflection angles of as much as 95 degrees without compromising the functionality of the articulation joint or drive shaft running therethrough during angulation and forcible loading of the delivery head. 
     Thus, according to one aspect of the present invention there is provided a medical device which is capable of approximating, ligating and fixating tissues and/or implants such as meshes and the like and can be used in both open and minimally invasive surgeries. The present device can be used in hernia mesh repair, both Inguinal and Ventral, Laparoscopic and open approaches. It can also be used for repairing pelvic or rectal prolapse. 
     The medical device includes a handle and a shaft having a proximal portion attached to a distal portion through an articulation region. The handle can be permanently attached to the shaft or removably attached thereto. The latter case enables use of several handle types with one shaft and/or reuse of the handle or use of one handle with several shafts. 
     The medical device further includes an articulation mechanism that is operable from the handle. The articulation mechanism is operable to select an articulation angle of the distal portion of the shaft. As is further described hereinunder, one embodiment of the articulation mechanism includes a first gear a second gear disposed in the articulation region and a third gear disposed on the articulation axis. The gears are engageable to transfer a rotation motion of the first gear in one plane into a respective rotation motion of the second gear and third gear in another plane. Preferably, the first gear rotates around an axis which is substantially perpendicular to an axis of the second and third gears. 
     The medical device further includes a drive mechanism that is operable from the handle. The drive mechanism is operable to deploy a fastener from a distal end of the distal portion. As used herein, the term fastener relates to any element capable of attaching to a tissue and/or implant. Examples include tacks, staples, anchors, screws and the like. 
     The drive mechanism includes an elongated member running the length of the shaft from the handle to the distal portion traversing the articulation region. The elongated member runs through the first gear and is in a co-axial arrangement therewith. 
     The articulation mechanism includes a hollow tube disposed (coaxially) within the proximal portion of the shaft with the first gear being disposed at the distal end of the tube. The gear teeth of the first gear are arranged around the tube or form an end thereof and are designed to selectively engage perpendicularly oriented teeth of the second gear disposed in the distal portion. The handle includes a roller-type interface (e.g. dial) that can be actuated to rotate the tube through a set of drive gears. The tube can be rotated in clockwise or counterclockwise directions (by rolling the dial forwards or backwards) one or more full rotations. The number of rotations required to achieve maximum articulation depends on the gear ratio provided between the first and second gears. 
     The roller interface can be used to set articulation at any angle between 0-95 degrees (between the proximal and distal portions) e.g. 10, 20, 40, 60, 80, 90 degrees. 
     The drive mechanism includes a motor, a battery pack and associated electronics and interface elements for controlling and driving the elongated member which in turn drives a fastener delivery mechanism disposed in the distal portion of the shaft. 
     The interface for the drive mechanism (e.g. trigger) allows a user to deliver a single fastener from the distal end of the shaft with a single push of the button. Delivery is actuated by the motor which rotates the elongated member a predetermined rotation angle or a preselected number of rotations for every push of the button. Rotation of the elongated member rotates the fastener delivery mechanism which in turn rotates and delivers a fastener. 
     The distal portion of the shaft which includes the fastener delivery mechanism also includes a fastener cartridge holding two or more (preferably 3, 4, 5, 6, 7, 10 or more) fasteners arranged along a length of the distal portion. The fasteners can be coupled to one another such that delivery of one fastener advances all the fasteners in the cartridge and ‘cocks’ the cartridge for subsequent delivery. 
     Since the distal portion of the shaft also functions as a fastener cartridge, it is preferably detachable from the proximal portion near (distal to) the articulation region. In order to enable such detachment and subsequent attachment of a second distal portion, the elongated member is attached to the fastener delivery mechanism through a detachable coupling such as a bayonet and an Allen pin to hex socket coupling. The distal portion of the shaft is attached to the proximal portion through a one sided or two sided joint which aligns the first and second gears of the articulation mechanism. The joint can be forced apart to disengage the gears and elongated member and detach the distal portion from the proximal portion. 
     As is mentioned hereinabove, the present inventors designed the articulation region of the device in order to maximize integrity and functionality under the most strenuous delivery conditions. 
     The positioning of the articulation gears and specifically the co-axial arrangement of the first gear with respect to the elongated member ensures that the first gear and elongated member cooperate to stabilize the articulation region and specifically the elongated member when rotated (by the motor) under loads applied to the device delivery head when the distal portion is angled with respect to the proximal portion. 
     Referring now to the drawings,  FIG. 1  illustrates an embodiment of the present device which is referred to hereinunder as device  10 . 
     Device  10  is configured for delivering a tack-type tissue fastener (e.g.  FIGS. 7 a - d   ) suitable for attaching a surgical mesh such as a hernia mesh to tissue. 
     Device  10  includes a handle  12  and a shaft  14  having a proximal portion  16  attached to a distal portion  18  through an articulation region  20 . Handle  12  can be permanently attached to shaft  14  (e.g. glued) or it can be attached thereto through a releasable coupling. 
     Handle  12  can be fabricated from a polymer such as Polycarbonate, ABS, Polyurethane using Injection molding, casting machining or 3D printing approaches. Preferably two halves forming the handle shell are fabricated using injection molding and the two halves are glued or mechanically adjoined around the internal components (further described hereinunder). Typical dimensions for handle  12  are 145-200 mm length, 35-55 mm height and 25-50 mm width. 
     Handle  12  is ergonomically shaped and is operated by wrapping two to four fingers around the handle body with the thumb over the articulation controls of interface  22  and forefinger at the fastener actuation button (trigger) of interface  22 . 
     Shaft  14  can be fabricated from a variety of medical grade stainless steel using machining approaches. Typical dimensions for shaft  14  are 200-300 mm length and 5-10 mm outer diameter. A lumen extends the length of shaft  12  and is 3-6 mm in diameter. 
     Proximal portion  16  of shaft  14  is connectable to handle  12  via a handle coupling mechanism  24 . Proximal portion  16  is typically 200-300 mm in length. Distal portion  18  is connected to proximal portion  16  distally to an articulation region  20 . 
     Distal portion  18  includes a tissue fastener cartridge  26  and mechanism for delivering one or more tissue fasteners through distal opening  28 . Distal portion  18  is typically 50-70 mm in length. 
     Handle  12  controls both articulation of distal portion  18  and delivery of tissue fasteners from cartridge  26 . 
       FIG. 2  illustrates handle  12  in greater detail showing interface  22  having a roller-type button  29  operable via a thumb and being for articulating distal portion  18  and a trigger-type button  30  operable via a forefinger and being for actuating release of a tissue fastener from opening  28 . 
     Interface  22  further includes a neutral activation button  32  for engaging/disengaging the articulation gear. When neutral activation button  32  is disengaged, the distal portion of the shaft can articulate freely (simply by pushing the handle against the shaft) and the fastener delivery button is deactivated (via switch  69 ,  FIG. 3 c   ) to prevent delivery of a fastener while the distal portion is articulated. Once an articulation angle is selected by the operator, engaging neutral activation button  32  locks articulation and allows delivery of a fastener from the distal end (as is indicated by a pair of LED lights on the handle). 
     Handle  12  further includes a port  36  (e.g. USB) for programming a microcontroller of the fastener delivery mechanism in handle  12 . Port  36  can be positioned at the proximal end of handle  12  (as is shown in  FIG. 2 ), or on a side face of handle  12 . 
     Distal end  37  of handle  12  includes a coupling mechanism  38  for attaching shaft  12  as well as internal shaft components for transferring actions from roller type button  29  to articulation region  20  and from trigger-type button  30  to cartridge  20 . The internal shaft components are further described hereinbelow. 
     Coupling mechanism  38  includes an outer lug  33  ( FIG. 4 d   ) which can be threaded over handle coupling mechanism  24 . Coupling mechanism  38  also includes a U-shaped connecting element  55  ( FIG. 3 b   ) which interconnects with U-shaped element of shaft  14 . 
       FIGS. 3 a - c    illustrate the internal components of handle  12 , showing roller-type button  29  and associated handle articulation mechanism  40  ( FIG. 3 a, c   ) and motor  42 , battery  44  and associated handle fastener mechanism  46  ( FIG. 3 b   ) for actuating U-shaped connecting element  55  and articulation in shaft  14  attached thereto. 
     Handle articulation mechanism  40  includes a transfer gear  48  for transferring rolling action of button  29  to a worm gear  50 . Worm gear  50  engages a drive gear  52  which is arranged around an articulation drive tube  55  running the length of a lumen of proximal portion  16  of shaft  14 . Neutral button  32  when fully depressed engages gear  52  and enables the transfer of torque to articulation connector  55  and when fully released disengages gear  52  providing free or roller button  29  -activated articulation. 
     Articulation drive tube  55  is a hollow, preferably metal alloy (e.g. stainless steel or titanium) tube having a length of 35-40 mm an outer diameter (OD) of 3.0-4.0 and an inner diameter (ID) of 2.2-2.5 mm. 
     Referring to  FIGS. 3 a - c   , button  29  and articulation mechanism  40  function as follows, thumbing button  29  (forwards or backwards) rotates gear  62  which is attached to thumbing button  29 . Gear  62  rotates gear  48  which in turn rotates gear  63 . Gear  63  is attached to worm gear  50  which in turn meshes with gear  52 . Rotation of gear  52  rotates shaft  64  which is meshed to shaft  65  ( FIG. 3 c   ) which is attached to shaft  55 . Rotation of shaft  55  rotates crown gear  88  (also referred to herein as first gear) of articulation region  20  ( FIGS. 5 a, c   ). Crown gear  88  is meshed to spur gear  90  (also referred to herein as second gear) and causes spur gear  90  to rotate. Spur gear  90  rotates spur gear  86  (also referred to herein as third gear) to thereby articulate distal portion  26  to a desired angle. 
     Handle fastener mechanism includes a spur gear  54  rigidly attached to shaft of motor  42 . Spur gear  46  transfers rotation of motor  42  to an elongated member  58  running the length of a lumen of shaft  12 . As is shown in  FIGS. 5 a  and 5 d   , elongated member  58  includes a flexible portion  60  which traverses articulation region  20 . Elongated member  58  is preferably a solid rod or tube fabricated from a metal alloy (e.g. stainless steel or titanium) or a polymer. Elongated member can be flexible or rigid (in portions other than flexible portion  60 ). 
     Motor  42  is preferably a stepper motor which rotates a predefined distance upon triggering of button  30 . 
     Handle fastener mechanism  46  (shown in  FIGS. 3 b - c   ) includes a spur gear  70  meshed with spur gear  54 . Gear  70  is rigidly attached to elongated member  58  and is driven by gear  54  in response to motor rotation. Elongated member  58  includes a connector  72  (e.g. hex-type connector) at its distal end. Connector  72  engages rod  73  (e.g. having an Allen interface) which is disposed within sleeve  75 . Sleeve  75  is attached to flexible member  60  which is in turn connected to the distal portion of elongated member  58  via an Allen-hex interface  74 . 
       FIGS. 4 a - c    illustrate shaft  14  in greater detail. Shaft  14  includes a coupling region  24  for engaging shaft  12  as well as drive tube  55  and elongate member  58  to handle  12 . 
     Distal portion  18  is shown in greater detail in  FIG. 4 c   , while coupling region  24  is shown in greater detail in  FIGS. 4 d    and  5   b.    
       FIGS. 4 a , 4 b  and 4 c    shows distal portion  18  in its integrated configuration being rigidly attached to shaft  16 .  FIGS. 4 d  and 5 b    show handle attachment collar  300  and coupling element  301  thereof. When collar  300  is fully engaged and attached to coupling mechanism  38 , shaft  65  and coupling element  301  are engaged and ready to transfer torque to distal portion  18  via shaft  65  and articulation activation via coupling element  301 . 
       FIG. 5 a    illustrates articulation region  20  showing mechanism  84  for transferring rotation of drive tube  55  into articulation at hinge  86 .  FIG. 5 a    also illustrates flexible portion  60  of elongated member  58 . 
     Flexible portion  60  of elongated member  58  is configured for compensating for changes in distances across the hinge region upon articulation of distal portion  18  with respect to proximal portion  16 . In that respect, flexible portion  60  is fabricated as an elastic structure that can lengthen and shorten without losing rotational rigidity. For example, flexible portion  60  can be fabricated as a closely packed coil, a multi strand stainless steel or titanium cable or a tube having cutouts along its length which allow the tube to elastically bend. 
     Alternatively, compensation for changes in distances across the hinge region upon articulation of distal portion  18  can be effected using a sliding sleeve in proximal portion  16  of shaft  14 . 
       FIG. 5 d    (which is also described above) illustrates a sliding-sleeve type shaft which includes a rod  73  which is disposed within sleeve  75  which is in turn attached to flexible member  60 . Rod  73  can slide back and forth within sleeve(s)  75  to compensate for any changes in the angle of flexible portion  60 . Thus rather than compensating for angulation by shortening or lengthening flexible portion  60 , this embodiment of the present invention provides compensation within proximal portion  16  of shaft  14 . 
     Mechanism  84  includes two perpendicularly-positioned gears a crown gear  88  and a spur gear  90 . As is illustrated in  FIG. 5 a   , flexible portion  60  of elongated member  58  runs through crown gear  88  (and is co-axial therewith) and parallel to spur gear  90 . 
       FIG. 5 c    illustrates articulation region  20  with elongated member  58  and flexible portion  60  removed in order to more clearly show the arrangement of gears  88  and  90  of mechanism  84 . 
     Crown gear  88  forms an end portion of drive tube  55  and is thus rotated with rotation of drive tube  55 . Gear  88  perpendicularly engages gear  90  and as such rotation of gear  88  rotates gear  90  in a plane perpendicular to the longitudinal axis of shaft  14 . Gear  90  engages gear  92  which is part of hinge region  86 . Rotation of gear  92  (via gear  90 ) angulates distal portion  18  with respect to proximal portion  16  around hinge  86  and thus results in articulation of shaft  14 . The gear ratio between the articulation gears can be 1:1. 
     As is shown in  FIG. 5 c   , articulation region  20  of shaft  14  also includes a coupling region  94  for distal portion  18  (not shown). Coupling region  94  serves two functions, coupling of distal portion  18  and included cartridge  20  to articulation region  20  of shaft  14  (thus connecting proximal portion  16  to distal portion  18 ) and coupling of elongated member  58  to a fastener drive mechanism  99  of cartridge  20  ( FIGS. 6 a - b   ). The latter can be achieved via mating of a hex socket  98  to an Allen pin  100  (of fastener drive mechanism). 
     Distal portion  18  and cartridge  20  are shown in greater detail in  FIG. 6 b   . Ten fasteners  102  are shown loaded within cartridge  20 . Pin  100  engages hex socket  98  of region  20  to enable rotation of fastener drive mechanism  99  via elongated member  58 . Release of fasteners  102  is affected as follows. 
     Allen pin  100  is rigidly attached to elongated threaded member  114 . A rotating nut  112  is threadably engaged to elongated threaded member  114 . Rotating nut  112  includes a protrusion on either side for engaging longitudinal slotted openings in elongated threaded member  114 . When Allen pin  100  rotates inside shaft  14 , rotating nut  112  moves forward within the longitudinal slotted openings in elongated threaded member  114  causing the tacks in front of rotating nut  112  to move forward and be deployed into the tissue. Spring clip  110  prevents unintended expulsion of the tacks by applying minimal pressure on the most distal tack until the tack is deployed as described above. 
     Several types of fasteners  102  can be used along with device  10  of the present inventions.  FIGS. 7 a - d    illustrate several examples of such fasteners which can be fabricated from a metal alloy (e.g. titanium, stainless steel) or a polymer (e.g. nylon). Fastener  102  can be fabricated from poly-lactic and/or -glycolic acid to enable biodegradation. Fasteners  102  include a tissue piercing end  104  (surgical needle type bevel) at a distal end of fastener body  106 . Fastener body  106  is preferably shaped from a round or square wire forming a base measuring about 3.6 mm 2  and a coil measuring 4.0 to 6.0 mm in length. The tack can have a pitch of 1.2 to 1.8 mm. 
     As is mentioned hereinabove, device  10  of the present invention can be used in a variety of fully open or minimally invasive medical procedures. 
     One preferred use for device  10  is tacking of a mesh in minimally invasive repair of an inguinal hernia. 
     Following insertion of a mesh via a working port and positioning of the mesh against the abdominal wall the device of the present invention is turned on and the shaft of choice is selected and attached to the handle. A cartridge is then attached to the shaft via the bayonet quick connect fitting. After verifying the shaft is straight, it is then inserted into the abdominal cavity via a standard access port with the appropriate size opening. The mesh is deployed via a dedicated port and held in position via a grasper, the shaft is then articulated such that the cartridge distal end is pressed perpendicularly against the mesh and the abdominal wall. The tack firing button is then actuated and a single tack is deployed into the mesh and tissue. The firing button is then released and the cartridge is repositioned at the next tacking location to deliver the next tack. This process is repeated until the mesh is satisfactorily attached, the shaft is then straightened and removed from the body. 
       FIGS. 8 a - c    illustrate an alternative embodiment of a shaft articulation unit which includes shaft  14  (composed of proximal portion  16  and distal portion  18 ), cartridge  26 , articulation control unit  22  and power transfer gears  54  and  65 . Unit  21  is a self contained unit which can be disposable thus lowering the wear of the power transfer unit and simplifying the use of the device. Unit  22  of this embodiment is based on a slider mechanism which is controlled via a slider button  23 . Sliding button  23  forwards (in the distal direction) and backwards (in the proximal direction) articulates the distal portion of shaft  18 . Unit  21  can be connected to device  10  via a snap and lock interface, a twist and lock interface or any other mechanical coupling mechanism known in the art. 
     The articulation region of this configuration is shown in  FIG. 8 c   . Proximal portion  16  and distal portion  18  (with cartridge  26 ) of shaft  14  are hingedly connected at  39 . The proximal end of a push/pull rod  40  is connected to articulation control unit  22  ( FIGS. 8 a - b   ) or to articulation control mechanism  102  ( FIGS. 12 a - c   ). Rod  40  runs through a longitudinal lumen of proximal portion  16  and its distal end is connected to slider  41  which is in turn hingedly connected to strut  42  at hinge  43 . The distal end of strut  42  is hingedly connected to distal portion  18  at hinge  45  which is distal (along shaft  14 ) to hinge  39 . As such, when rod  40  is pulled towards the user (using the sliding button of articulation control unit  22  or by rotating assembly  214  described below) distal portion  18  pivots around hinge  39  and distal portion  18  angles with respect to proximal portion  16 . 
       FIG. 12 a - b    illustrate yet another embodiment of a shaft articulation unit. In this embodiment, shaft articulation is controlled by a user through an interface provided on the proximal portion of the shaft. 
       FIG. 12 a    illustrates an articulated exchangeable shaft  100  (also referred to hereinunder as shaft  100 ) having a proximal portion  106  attached to a distal portion  108  through an articulation region  120 . Articulation region  120  of shaft  100  can be any of the articulation regions described hereinabove (strut or gears). Shaft  100  also includes an articulation control mechanism (and interface)  102  located at a proximal portion  104  of shaft  100 . Shaft  100  is attachable to a handle for providing functions such as tissue fastener delivery (the handle can be similar to handle  12  described hereinabove but without articulation control). Shaft  100  also can also include a micro switch which is activated when shaft  100  is coupled to a handle; the micro switch allows use of the handle with shaft  100  (similar to that described hereinabove for device  10 ). 
       FIG. 12 b    illustrates the internal components of articulating mechanism  102  of shaft  100 . 
     Articulating mechanism  102  includes a frame  201  having slots  202  on an inner side of an upper bridge section. Mechanism  102  further includes an external articulation piston  203  (hereinafter piston  203 ) and an internal articulation piston  204  (hereinafter piston  204 ). Pistons  203  and  204  are actuatable against springs  205  and  206  (respectively). 
     Pushing piston  204  down (manually) against an upper spring  205  releases articulation lock pin  207  (hereinafter pin  207 ) from slot  202  in the upper bridge of frame  201 . 
     Release of pin  207  enables manual rotation of assembly  214  around a pivot point (not shown) at the bottom of piston  203 . Rotation (left to right in the view shown in  FIG. 9 b   ) of assembly  214  is transferred through an articulation movement transfer pin  208  to an articulation movement connector  209  and articulation bar  212  and to articulation region  120  of shaft  100 . Once a user selects the desired deflection angle for distal portion  108 , piston  204  can be released to allow pin  207  to engage a specific slot  202 . 
     When piston  204  is pressed down, it pushes down on spring  206  which in turn pushes down on lower piston  210 . Since spring  205  has a higher spring force constant than spring  206 , once lower piston  210  is pressed, an articulation disable micro switch  211  is actuated (pushed) to disable the handle motor trigger before pin  207  is released from a groove  202  to allow articulation angle setting. 
     As used herein the term “about” refers to ±10%. 
     Additional objects, advantages, and novel features of the present invention will become apparent to one ordinarily skilled in the art upon examination of the following examples, which are not intended to be limiting. 
     EXAMPLE 
     Reference is now made to the following example, which together with the above descriptions, illustrate the invention in a non limiting fashion. 
     Example 1 
     Device Prototype 
     A prototype of the present device was developed in order to test various device parameters.  FIG. 9  illustrates the various components of the prototype device. 
     The prototype device was initially used to test parameters such as motor requirements (torque and force that would enable tack delivery), control (PC board selection), device integrity (e.g. of shaft-handle interface and shaft) safety features, and human interface. Once these parameters were optimized, the device was utilized to test function (articulation and delivery). 
       FIG. 10  illustrates tack delivery into a surgical mesh disposed over a material mimicking live human tissue.  FIG. 11  illustrates the delivered tacks showing mesh fastening to the tissue-like material. 
     Example 2 
     Articulating Shaft Prototype 
     A prototype of an articulating shaft having a shaft-positioned articulation control mechanism and user interface ( FIG. 13 ) was fabricated using standard CNC, Swiss type CNC and wire electro-erosion. A functional module was assembled and tested. Functional features, such as articulation control and torque delivery were successfully achieved. 
     It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination. 
     Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.