Abstract:
A biopsy device handle for use with a biopsy device needle set, comprising a housing, a throw depth selection assembly, a cocking assembly, a carriage assembly, a needle set driver assembly, and an actuating assembly. A safety feature may be incorporated into the device to reduce or eliminate the chance of unintentional firing of the biopsy device.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/182,006, filed May 28, 2009, which application is incorporated herein by reference in its entirety. 
     
    
     FIELD OF INVENTION 
       [0002]    The present invention relates generally to handles for biopsy devices. 
       BACKGROUND OF THE INVENTION 
       [0003]    It is often desirable and frequently absolutely necessary to sample or test a portion of tissue from humans and even animals to aid in the diagnosis and treatment of patients with cancerous tumors, pre-malignant conditions and other diseases or disorders. Typically in the case of cancer or the suspicion of malignant tumors, a very important process called tissue biopsy is performed to establish whether cells are cancerous. 
         [0004]    Biopsy may be done by an open or closed technique. Open biopsy removes the entire tissue mass or a part of the tissue mass. Closed biopsy on the other hand is usually performed with a needle-like instrument and may be either an aspiration (hollow needle on a syringe) or a core biopsy (special tissue cutting needle design). In needle aspiration biopsy, individual cells or clusters of cells are obtained for cytologic examination. In core biopsy, a segment of tissue is obtained for histologic examination which may be done as a frozen section or paraffin section. 
         [0005]    The methods and procedures of obtaining tissue samples for cytologic or histologic examination have been performed historically by manual insertion and manipulation of the needle. These procedures are performed “blind” by the physician and guided by “feel” and known anatomic “landmarks”. 
         [0006]    Tumors are first noted in a patient by one of three ways, palpation, x-ray imaging or ultrasound imaging. Once a tumor is identified, a biopsy procedure is performed. Modern medical opinion dictates early detection of cancer, which increases the likelihood of successful treatment. Biopsies are performed on “Tumor Masses” as small as 2 millimeters in diameter. This procedure is performed under ultrasound or x-ray guidance. Tumors of this size cannot be biopsied reliably by hand since the tumor is about the same size as the biopsy needle. Manual attempts at biopsy can push the tumor away without piercing the mass. Automatic puncture devices are needed to accelerate the needle at such a velocity that even a small tumor can be pierced. 
         [0007]    Two very important innovations in the field of medical technology have influenced the field of tissue biopsy in the last five years. One, the use of tissue imaging devices which allow the physician to “see” inside the body and visually guide the needle to the tumor mass. Two, the invention of the Automatic Core Biopsy Device (ACBD) or “Biopsy Gun”. The ACBD is an instrument which propels a needle set with considerable force and speed to pierce the tumor mass and collect the tissue sample. This ACBD device has allowed physicians to test tissue masses in the early stages of growth and has contributed to the medical trend of early diagnosis and successful treatment of cancer. 
         [0008]    Examples of such ACBD devices have been described with respect to the collection of tissue samples in U.S. Pat. Nos. 4,651,752, 4,702,260, and 4,243,048. 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    There is provided a biopsy device handle for use with a biopsy device needle set, including a housing, a throw depth selection assembly, a cocking assembly, a carriage assembly, a needle set driver assembly, and an actuating assembly. In certain embodiments, the biopsy device handle further includes a stylet assembly. 
         [0010]    In certain embodiments, the needle set driver assembly includes a plurality of cannula drivers for drivably mounting needle set cannulae. In certain of these embodiments, at least one cannula driver is rotatable relative to the housing. 
         [0011]    In certain embodiments, the biopsy device handle permits an operator of the device to fully cock the device one-handedly. 
         [0012]    These and other aspects of the present invention will become evident upon reference to the following detailed description and attached drawings. In addition, various references are set forth herein which describe in more detail certain procedures and/or compositions (e.g.; devices and their components), and these references are incorporated herein by reference in their entirety. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a cross-sectional perspective view seen from above a biopsy device handle in accordance with an embodiment of the invention. 
           [0014]      FIG. 2  is a cross-sectional perspective view of a biopsy device handle when the device is in a cocked position in accordance with an embodiment of the invention shown in  FIG. 1 . 
           [0015]      FIG. 3  is a cross-sectional perspective view from above of a biopsy device handle when the device is in a fired position in accordance with an embodiment of the invention shown in  FIG. 1 . 
           [0016]      FIG. 4  is a cross-sectional view from above of a biopsy device handle when the device is in a fired position in accordance with an embodiment of the invention shown in  FIG. 1 . 
           [0017]      FIG. 5  is a cross-sectional view from above of a biopsy device handle after a first cocking stroke in accordance with an embodiment of the invention shown in  FIG. 1 . 
           [0018]      FIG. 6  is a cross-sectional view from above of a biopsy device handle after a second cocking stroke in accordance with an embodiment of the invention shown in  FIG. 1 . 
           [0019]      FIG. 7  is an exploded view of a biopsy device handle in accordance with an embodiment of the invention shown in  FIG. 1 . 
           [0020]      FIG. 8  is a perspective view of a biopsy device handle in accordance with another embodiment of the invention. 
           [0021]      FIG. 9  is a cross-sectional perspective view of a biopsy device handle in accordance with an embodiment of the invention shown in  FIG. 8 . 
           [0022]      FIG. 10  is a cross-sectional view from above of a biopsy device handle after a second cocking stroke in accordance with an embodiment of the invention shown in  FIG. 8 . 
           [0023]      FIG. 11  is an exploded view of a biopsy device handle in accordance with an embodiment of the invention shown in  FIG. 8 . 
           [0024]      FIG. 12  is a perspective exterior view of a biopsy device handle in accordance with an embodiment of the invention. 
           [0025]      FIG. 13  is a perspective exterior view of a biopsy device handle in accordance with an embodiment of the invention shown in  FIG. 12 . 
           [0026]      FIG. 14  is a perspective exterior view of a biopsy device handle in accordance with an embodiment of the invention shown in  FIG. 12 . 
           [0027]      FIG. 15  is a perspective exterior view of a biopsy device handle in accordance with an embodiment of the invention. 
           [0028]      FIG. 16  is an exploded view of a biopsy device handle in accordance with an embodiment of the present invention. 
           [0029]      FIG. 17  is an expanded view of an actuator present within a biopsy device handle in accordance with one embodiment of the present invention. 
           [0030]      FIG. 18  is a cross sectional perspective view illustrating a needle set driver guide engaged against an actuator, to prohibit unintended firing of one embodiment of the biopsy device of the present invention. 
           [0031]      FIG. 19  is a perspective view illustrating various positions for the throw depth stop of the needle set driver guide as located within the biopsy device handle in one embodiment of the present invention. 
           [0032]      FIG. 20  is a cross sectional perspective view illustrating an embodiment of the present invention wherein a needle set driver guide is not engaged against an actuator, thereby allowing the biopsy device to be fired. 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0033]    Indications of lateral direction such as ‘from above’, ‘upper’, ‘lower’ are defined by the views of the Figures. The terms “proximal” and “distal” refer to the person from whom a biopsy sample is extracted; the terms “front” and “rear” have a corresponding meaning. Thus, the proximal end of a biopsy apparatus is its front end, pointing to the patient. 
         [0034]    One embodiment of a biopsy device handle is illustrated in  FIGS. 1 to 7  with a needle set including a cannula set (which may include one or more cannulae) extending through the proximal end of the handle. The handle of this embodiment is provided with a mechanism allowing two cocking strokes to fully cock the device, such that the operator of the device may operate it with one hand. In this embodiment, the length of each cocking stroke is selected to correspond to the motion that an operator&#39;s digit (on the same hand used the operator to hold the device) may comfortably impart to it, and the sum of the lengths of the cocking strokes is equal to or greater than, depending on the throw depth and whether or not a twisting motion is to be imparted to all or part of the needle set, the distance traveled by the needle set from a fully cocked position to a fully fired position. In embodiments wherein the distance traveled by a biopsy needle set is greater (for example, where throw depths are greater), it may be desirable to provide additional cocking strokes. In yet other embodiments, only one cocking stroke may be required to fully cock the device, whether the operator uses two hands or one. For example, in embodiments for which it is desired to have two-handed operation of a biopsy device, such that one hand of an operator is used to hold the device while the other is used to cock it, a single cocking stroke that is equal or greater in length than the distance traveled by a needle set from full cocking of the device to full firing could be used. In other embodiments, a mechanism allowing for full single-handed cocking of a biopsy device may be provided with a gear system or the like. 
         [0035]    Referring now to  FIG. 1 , the biopsy device handle  100  includes a housing  104 , a cocking assembly  108 , a carriage assembly  124 , an actuator assembly  132 , needle set driver assembly  146 , and a throw depth stop  164 . Referring additionally to  FIGS. 2 to 7 , cocking actuator  114  of cocking assembly  108  extends out of housing  104  through aperture  118 , and may additionally be provided with cocking actuator button  110 . Cocking lever  112  of cocking assembly  108  engages one of a plurality of catches  120  of carriage assembly  124 . Carriage drive assembly  156 , represented in this embodiment as a pair of tension springs affixed at the other of their ends to mounts  158  near the proximal end of the housing  104 , engages carriage  126  of assembly  124 , which includes carriage arms  128  that, during the first cocking stroke, slidingly engage intermediate catch guides  160  on housing  104 . Carriage  126  also engages outer cannula driver  150 , to which outer cannula  144  is drivably mounted, and outer cannula driver  150  in term engages inner cannula driver  148 , to which inner cannula  142  is drivably mounted. In certain other embodiments, the carriage may engage another cannula driver, or all such drivers. Inner and outer cannulae are annularly arranged around a stylet. In the present embodiment, stylet assembly  140  includes a stylet with a stylet mount at one end thereof, disposed distally inside housing  104 . (In various other embodiments, the needle set may also include a stylet, thereby obviating the need to provide one in the device handle.) Inner cannula  142  and outer cannula  144  extend through an opening in the proximal end of the housing  104 , which may be reinforced with a needle set guide  106  (which needle set guide may be integral part of the housing  104  or mounted thereon) to further stabilize guidance of needle set  102 . 
         [0036]    Inner cannula driver  148  and outer cannula driver  150  are disposed laterally in series and are coupled by cannula driver coupler  154 , thus comprising needle set driver assembly  146 ; as such, displacement of one cannula driver causes displacement of the other. Both drivers are laterally displaceable along needle set driver guide  152 . Needle set driver guide  152  is mounted on an inner surface of housing  104  and includes at its proximal end a barrier, comprising part of throw depth stop  164 , which determines the travel distance of outer cannula driver  150  and thereby prevents needle set  102  from traveling past the preselected throw depth. 
         [0037]    In the present embodiment, the device is cocked in two strokes, the first of which displaces the carriage from its initial uncocked position laterally through the housing to an intermediate position. Referring to  FIG. 5 , as the device is being cocked during such a first cocking stroke, cocking assembly  108  is displaced distally as the cocking assembly is actuated by the operator applying force to cocking actuator button  110  covering cocking actuator  114 . As cocking assembly  108  moves distally, cocking lever  112  engages one of the distal carriage catches  120  and thereby moves carriage assembly  124  along with it. Resilient carriage arms  128  and carriage arm ends  130  are thus displaced along intermediate catch guides  160  (which, in the present embodiment, are located on the inner surface of housing  104 ). As intermediate catch guides  160  do not, in the present embodiment, run parallel to a central axis of the handle  100  but rather splay out at their distal ends towards the sides of the handle, carriage arms  128  are deformed slightly to splay out towards the sides of the handle as they travel distally along intermediate catch guides  160  during the first cocking stroke. Thus, when carriage arms  128  reach the distal ends of intermediate catch guides  160 , carriage arms  128  tend to resile back towards the centre of the handle, to the extent that the continued engagement of carriage arms  128  with intermediate catch guides  160  permit. Once carriage arm ends  130  have moved back towards the center of the handle, the engagement of carriage arm ends  130  with the intermediate catches  162  at the distal end of the intermediate catch guides  160  prevent carriage arms  128  from sliding proximally while carriage drive assembly  156  prevents carriage arms  128  from sliding distally without the application of additional force to displace ends  130  from intermediate catches  162  (as would be provided, for example, with the force of a second cocking stroke). At the same time, referring now to  FIG. 2 , inner cannula driver  148  and outer cannula driver  150  may travel along needle set driver guide  152  until carriage arm ends  130  reach the intermediate catches  162 . This is the intermediate stop, or partially cocked, position. 
         [0038]    Once the intermediate stop position is reached and carriage arm ends  130  are engaged in intermediate catches  162 , and no more force is applied by the operator to complete the first cocking, cocking repositioner  116  (which, in the present embodiment, is represented by a tension spring attached at one end to the cocking assembly and at its other end to a proximal location on the inner surface of housing  104 ) urges cocking assembly  108  back to its original, uncocked position. 
         [0039]    As, at the end of the first cocking stroke, carriage  126  is displaced distally relative to cocking assembly  108 , cocking lever  112  engages one of the proximal cocking catches  120  of carriage assembly  124 . As force of the second cocking stroke is applied, cocking lever  112  is again displaced distally and with it displaces carriage  126  further distally, causing the release of carriage arm ends  130  from intermediate catches  162 . This time, resilient carriage arms  128  and carriage arm ends  130  are displaced along main catch guides  170  (which, like intermediate catch guides  160 , angle away from the central axis of the device handle  100 ), deforming carriage arms  128  out towards the sides of the handle as they travel distally along main catch guides  170 . Carriage arms  128  are thus advanced towards main catches  172 , at which carriage arms  128  tend to resile back towards the central axis of the handle, and arm ends  130  are caught in catches  172 . Carriage  126  is prevented from moving further distally by tension in the carriage drive assembly  156  and proximally by engagement of arm ends  130  in main catches  172 . Displacement of carriage  126  during the second cocking stroke results in the displacement of both outer cannula driver  150  and inner cannula driver  148  further distally along needle set driver guide  152  until carriage arm ends  130  come to rest in main catches  172 . This is the fully cocked position; once it is reached and the operator is no longer applying a cocking force, cocking repositioner  116  again returns cocking assembly  108  to its initial position. 
         [0040]    As the depth in tissue to which the needle set is to travel may be set using the throw depth selector  166 , the position of throw depth selector  166  and throw depth stop  164  limits the distance which inner cannula driver  148  and outer cannula driver  150 , and their respective cannulae, may travel proximally. Throw depth stop  164  may be configured to provide any number of throw depths within a given range (which range is determined by the length of the housing opening along which the throw depth selector  166  may be displaced and set), or it may be configured to provide a limited number of throw depths. Throw depth stop  164  is associated with needle set driver guide  152 , and displacement of throw depth stop  164  results in displacement of needle set driver guide  152  in housing  104 , thus determining how far carriage  126 , and therefore inner cannula driver  148  and outer cannula driver  150 , may travel within housing  104  to throw depth stop  164  at the proximal end of guide  152 . 
         [0041]    Once the throw depth selected and the device is fully cocked, the needle set may be injected for tissue sampling at a tissue entry site that the device operator has selected. To actuate the device, the operator moves actuator safety  138  below actuator assembly  132  (which, in the present embodiment, also includes actuator  134  and actuator repositioner  136 ) from its blocking, or “safe”, position which prevents actuating the device to its actuating position centrally below actuator  134  (as illustrated in  FIGS. 4 and 5 ) and then presses actuator  134 , urging carriage arm ends  130  out from main catches  172 . After releasing carriage arm ends  130  from main catches  172 , actuator  134  is returned to its unactuated position by actuator repositioner  136 . The operator&#39;s pressing action causes actuator  134  to be displaced proximally towards the carriage arm ends  130  in the main catches  172 , and forces the carriage arm ends  130  out of the main catches  172 . This release of the carriage arm ends  130  allows the release of potential energy in carriage drive assembly  156  (originally stored by the two-stage cocking of the device), which causes carriage assembly  124 , and therefore inner cannula driver  148  and outer cannula driver  150 , to travel proximally until outer cannula driver  150  reaches the proximal end of needle set driver guide  152 . Accordingly, the proximal ends of inner cannula  142  and outer cannula  144  travel away from the device and towards the tissue sampling site. 
         [0042]    For embodiments in which a twisting motion is to be imparted to at least one of the cannulae, the corresponding cannula driver rotates during actuation of the device. For cylindrical cannula drivers, the driver may, by way of example, be part of a worm drive (wherein the driver includes a worm on its outer surface and the needle set driver guide or carriage assembly includes a worm gear, or vice versa) or, inter alia, be provided with a spiral groove and pin assembly. It is to be understood that various types of rotation-imparting means may be suitably used, the selection and configuration of which may depend on factors such as manufacturing costs, the degree of rotation desired, and the needle set travel distance over which such rotation is to be imparted. 
         [0043]    In the embodiment illustrated in  FIGS. 1 to 7 , outer cannula driver  150  includes a helical groove  174  on its outer surface which slidingly engages pin  122  (shown in  FIG. 1 ) of carriage assembly  124 . Thus, when the proximal end of outer cannula driver  144  reaches the distal end of throw depth stop  164  and is prevented from travelling further proximally, carriage assembly  124  continues to move proximally for a distance no greater than the length of helical groove  174  and so causes outer cannula driver  144  to rotate in order to maintain engagement with pin  122 . In various other embodiments, the helical groove might be provided on a carriage assembly and the pin might be provided on the surface of the cannula driver corresponding to the cannula which is to be twisted. In yet other embodiments, one of the helical groove and pin may be disposed on the cannula driver of interest, while the other of the pair may be disposed on a throw depth stop or needle set driver guide. 
         [0044]    Once the device has been actuated and injected into tissue, and a biopsy sample captured by the needle set, the needle set may be withdrawn from the tissue site. To retrieve the biopsy sample from the needle set, the device may be cocked again to draw the needle set back. In the embodiment shown in  FIGS. 1 to 7 , cocking the device after actuation causes the rotation of outer cannula driver  150  in a direction opposite to that which was caused by actuation, and urges both inner and outer cannula drivers  148  and  150  distally. As inner and outer cannulae  142  and  144  are nestedly arranged over the stylet portion of assembly  140  and as stylet assembly  140  remains stationary, the distal movement of cannula drivers  148  and  150  causes cannulae  142  and  144  to travel distally and the proximal end of stylet assembly  140  to inhibit the corresponding distal movement of the biopsy sample. In this fashion, the distal movement of cannulae  142  and  144  exposes and releases the biopsy sample. 
         [0045]    Referring now to the embodiment shown in  FIGS. 8 to 11 , biopsy device handle  200  as shown in  FIG. 1  includes cocking button  210  slidably disposed in aperture  218  and throw depth selector  266  near the proximal end of housing  204 , actuator  234  disposed at the distal end of housing  204 , and actuator safety  236  disposed near the distal end of housing  204 . Needle set  202  is mounted in device handle  200 . Referring additionally to  FIGS. 9 to 11 , the device is cocked in two strokes, the first of which displaces carriage  226  from its initial uncocked position laterally through housing  204  to an intermediate position. Cocking assembly  208  is displaced distally as it is actuated by the operator applying force to cocking actuator button  210 . As cocking assembly  208  moves distally, cocking lever  212  engages one of the distal carriage catches  220  and thereby moves carriage assembly  224  along with it. Resilient carriage arms  228  and carriage arm ends  230  are thus displaced to an intermediate (or partly cocked) position. At the same time, inner cannula driver  248  and outer cannula driver  250 , coupled by cannula driver coupler  254 , travel along needle set driver guide  252  until carriage arm ends  230  reach the intermediate position. Cocking repositioner  216  (which, in the present embodiment, is represented by a tension spring attached at one end to the cocking assembly and at its other end to a proximal location on the inner surface of housing  204 ) then urges cocking assembly  208  back to its original, uncocked position. 
         [0046]    As, at the end of the first cocking stroke, carriage  226  is displaced distally relative to cocking assembly  208 , cocking lever  212  engages one of the proximal cocking catches  220 . As force from the second cocking stroke is applied, cocking lever  212  is again displaced distally and with it displaces carriage  226  further distally, along main catch guides  270  until carriage arm ends  230  are caught in main catches  272 . Carriage  226  is prevented from moving further distally by tension in the carriage drive assembly  256  and proximally by engagement of arm ends  230  in main catches  272 . Displacement of carriage  226  during the second cocking stroke results in the displacement of both outer cannula driver  250  and inner cannula driver  248  further distally along needle set driver guide  252  until carriage arm ends  230  come to rest in main catches  272 . This is the fully cocked position; once it is reached and the operator is no longer applying a cocking force, cocking repositioner  216  again returns cocking assembly  208  to its initial position. 
         [0047]    As throw depth stop  264  is associated with needle set driver guide  252 , and displacement of throw depth stop  264  results in displacement of needle set driver guide  252  in housing  204 , the operator may set throw depth stop to the desired depth (that is, the depth of the tissue from which a biopsy sample is desired) in order to determine how far carriage  226 , and therefore inner cannula driver  248  and outer cannula driver  250 , may travel within housing  204  to throw depth stop  264  at the proximal end of guide  252 . 
         [0048]    Once the throw depth is selected and the device is fully cocked, the needle set may be injected for tissue sampling at a tissue entry site that the device operator has selected. To actuate the device, the operator moves actuator safety  238  out from its “safe” position preventing proximal displacement of actuator assembly  232  and then presses actuator  234 , urging carriage arm ends  230  out from main catches  272 . After releasing carriage arm ends  230  from main catches  272 , actuator  234  is returned to its unactuated position by actuator repositioner  236 . The operator&#39;s pressing action causes actuator  234  to be displaced proximally towards the carriage arm ends  230  in the main catches  272 , and forces the carriage arm ends  230  out of the main catches  272 . This release of the carriage arm ends  230  allows the release of potential energy in carriage drive assembly  256  (originally stored by the two-stage cocking of the device), which causes carriage  226 , and therefore inner cannula driver  248  and outer cannula driver  250 , to travel proximally until outer cannula driver  250  reaches the proximal end of needle set driver guide  252 . Accordingly, the proximal end of needle set  202  travels away from the device and towards the tissue sampling site. 
         [0049]    For embodiments in which a twisting motion is to be imparted to at least one of the cannulae, the corresponding cannula driver rotates during actuation of the device. For cylindrical cannula drivers, the driver may, by way of example, be part of a worm drive (wherein the driver includes a worm on its outer surface and the needle set driver guide or carriage assembly includes a worm gear, or vice versa) or, inter alia, be provided with a spiral groove and pin assembly. It is to be understood that various types of rotation-imparting means may be suitably used, the selection and configuration of which may depend on factors such as manufacturing costs, the degree of rotation desired, and the needle set travel distance over which such rotation is to be imparted. 
         [0050]    In the embodiment illustrated in  FIGS. 8 to 11 , outer cannula driver  250  includes a helical groove  274  on its outer surface which slidingly engages pin  222  (shown in  FIG. 2 ) of carriage assembly  224 . Thus, when the proximal end of outer cannula driver  244  reaches the distal end of throw depth stop  264  and is prevented from travelling further proximally, carriage assembly  224  continues to move proximally for a distance no greater than the length of helical groove  274  and so causes outer cannula driver  244  to rotate in order to maintain engagement with pin  222 . In various other embodiments, the helical groove might be provided on a carriage assembly and the pin might be provided on the surface of the cannula driver corresponding to the cannula which is to be twisted. In yet other embodiments, one of the helical groove and pin may be disposed on the cannula driver of interest, while the other of the pair may be disposed on a throw depth stop or needle set driver guide. 
         [0051]    Once the device has been actuated and injected into tissue, and a biopsy sample captured by the needle set, the needle set may be withdrawn from the tissue site. To retrieve the biopsy sample from the needle set, the device may be cocked again to draw the needle set back. In embodiments including a rotating cannula driver, cocking the device after actuation causes the rotation of the cannula driver in a direction opposite to that which was caused by actuation. Post-actuation cocking also urges both cannula drivers distally. As inner and outer cannulae  242  and  244  are annularly arranged over the stylet portion of assembly  240  and as stylet assembly  240  remains stationary, the distal movement of cannula drivers  248  and  250  causes cannulae  242  and  244  to be drawn distally over the proximal end of stylet assembly  240 , thereby exposing and releasing the biopsy sample. 
         [0052]      FIGS. 12 to 14  provide various views of a biopsy device handle exterior of an embodiment of the invention. Device handle  300  includes housing  304  having a distal end  378  and a proximal end  376 , wherein the proximal end (through which a needle set would extend) is substantially circular. One side of housing  304  is provided with finger grips  368  to increase the security of the operator&#39;s hold on the device. Finger grips  368 , actuator  310 , and cocking button  334  are all arranged on three adjacent sides of the housing, with actuator  310  and cocking button  334  being disposed near distal end  378  of housing  304 . Throw depth selector  366  may be disposed near distal end  378  either adjacent to finger grips  368  or on the remaining free side of housing  304 . Assuming a right-handed operator of the device, the operator would align his or her fingers along finger grips  368  such that distal end  378  would be adjacent to the operator&#39;s wrist, and leaving the thumb free to slide cocking button  334  along housing aperture  318  to cock the device and push actuator  310  to fire it. (Of course, it is to be understood that the arrangement of parts illustrated in these figures could be reversed to accommodate a left-handed operator.) 
         [0053]      FIG. 15  illustrates another biopsy device handle exterior of an embodiment of the invention. Device handle  400  includes housing  404  having a distal end  478  and a proximal end  476 , wherein the proximal end (through which a needle set would extend) is substantially ovoid. One side of housing  404  is provided with a distension  468  of housing  404  to increase the comfort and security of the operator&#39;s hold on the device. Distension  468 , actuator  410 , and cocking button  434  are all arranged on three adjacent sides of the housing, with actuator  410  and cocking button  434  being disposed near distal end  478  of housing  304  while distension  468  is disposed from about the middle of the housing to about its proximal end. Throw depth selector (not shown) may be disposed near distal end  378  either adjacent to distension  468  or on the remaining free side of housing  404 . Assuming a right-handed operator of the device, the operator would align his or her fingers along distension  68  such that distal end  478  would be adjacent to the operator&#39;s wrist, and leaving the thumb free to apply force to cocking button  434  to cock the device and push actuator  310  to fire it. (Of course, it is to be understood that the arrangement of parts illustrated in these figures could be reversed to accommodate a left-handed operator.) 
         [0054]      FIG. 16  provides an exploded view of another embodiment of the biopsy device handle of the present invention. In this embodiment, biopsy device handle  500  includes cocking button  510  which may be slidably disposed in aperture  518  of housing  504 . Also present are cocking assembly  508  (which functions equivalently to features  108  and  208 ), actuator  534  (which functions equivalently to features  134  and  234 ) having an associated throw depth selector  566  (which in large part functions equivalently to  166  and  266 ), carriage  526  (which functions equivalently to features  126  and  226 ), stylet  540  (which functions equivalently to features  140  and  240 ), needle set driver guide  552  (which functions equivalently to features  152  and  252 ) associated with a throw depth stop  564  (which functions equivalently to  164  and  264 ), springs  556 , and actuator safety  538  (which functions equivalently to  138  and  238 ). 
         [0055]    The actuator  534  of  FIG. 16  is shown in expanded view in  FIG. 17 . The actuator  534  includes one half of a locking mechanism, shown as teeth  534   a . The teeth engage complementarily shaped openings  504   a  in housing  504  to provide a locked position, where this locked position is held in place by contact between the actuator and the needle set driver guide  552 . In turn, the needle set driver guide  552  is held in place as it rests against rails  504   b  of the housing  504 . The rails  504   b  are located between the openings  504   c , where the throw depth stop  564  can fit into any of the predetermined openings  504   c  as shown in  FIG. 19 , to thereby set the depth to which the needle will enter tissue to obtain a biopsy sample. When the throw depth stop  564  is located within an opening  504   c , as shown in  FIG. 19 , the needle set driver guide will displace off the rails  504   b  and thereby be allowed to move away from the actuator  534 , as shown in  FIG. 20 . With the needle set driver guide  552  no longer pressed against the actuator  534 , the teeth  534   a  can disengage from the openings  504   a , and the actuator  534  can move in a longitudinal direction. However, when the throw depth stop  564  is located between openings  504   a , then the needle set driver guide  552  will rest on rails  504   b  and cause teeth  534   a  to be locked into openings  504   a , thus precluding the biopsy device from firing. 
         [0056]    Although the present invention has been shown and described in detail with regard to only a few exemplary embodiments of the invention, it should be understood by those skilled in the art that it is not intended to limit the invention to the specific embodiments disclosed. Various modifications, omissions, and additions may be made to the disclosed embodiments without materially departing from the novel teachings and advantages of the invention, particularly in light of the foregoing teachings. Accordingly, it is intended to cover all such modifications, omissions, additions, and equivalents as may be included within the spirit and scope of the invention as defined by the following claims.