Patent Publication Number: US-2015080759-A1

Title: Biopsy device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of and claims the benefit of priority under 35 U.S.C. §120 to U.S. application Ser. No. 11/456,969, filed Jul. 12, 2006, the entire contents of which is hereby fully incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The invention relates to biopsy devices, and to related methods, components, and systems. 
     BACKGROUND 
     Biopsy devices can be used to obtain a tissue specimen from a subject. The tissue specimen can be examined, for example, to determine malignancy. 
     SUMMARY 
     The invention relates to biopsy devices, and to related methods, components, and systems. 
     In one aspect, the invention features a biopsy system that includes a sampling portion defined by first and second components that are moveable relative to each other. In a first position the sampling portion is open, and in a second position the sampling portion is closed. The first component has a wall with a first region and a second region angled relative to the first region of the first component. The second component has a wall with a first region and a second region angled relative to the first region of the second component. 
     Embodiments can include one or more of the following features. 
     When in the second position, the first region of the first component and the first region of the second component can form an approximately tubular section. When in the second position, the first and second components can form a tip. When in the first position, the first component can be at least partially disposed within the second component. The second component moves relative to the first component when going from the first position to the second position, and the wall of the second component has an edge configured to cut tissue. 
     The biopsy device can also include a handpiece and a cannula. The cannula can have proximal and distal ends. The proximal end can be operably coupled with the handpiece, and the distal end can be operably coupled with the sampling portion. The second component can be partially disposed in the cannula, and the second component can be rotatably coupled to the cannula. The first component can be integral with the cannula. 
     The biopsy device can also include a device configured to form a pressure gradient in the biopsy device. The device can be operatively coupled with the sampling portion so that, during use of the biopsy device, the device forms a pressure gradient in a direction non-parallel to the longitudinal axis of the sampling portion of the biopsy device. In some embodiments, the biopsy device is devoid of a device that forms a pressure gradient in the biopsy device. 
     The first and second components can be rotatable relative to each other. The biopsy device can have a dead space of less than about five millimeters (e.g., less than about four millimeters, less than about three millimeters, less than about one millimeter). 
     In an additional aspect, the invention features a biopsy device that includes a sampling portion and a device configured to form a pressure gradient in the biopsy device. The sampling portion has a longitudinal axis. The device is operatively coupled with the sampling portion so that, during use of the device, the device forms a pressure gradient in a direction non-parallel to the longitudinal axis of the sampling portion. 
     Embodiments can include one or more of the following features. 
     The non-parallel direction can be a direction substantially perpendicular to the longitudinal axis of the sampling portion. The first device can be configured so that, during use of the first device, the first device draws tissue into the sampling portion. 
     The biopsy device of can include a second device configured to form a pressure gradient in the biopsy device. The second device can be operatively coupled with the sampling portion so that, during use of the second device, the second device forms a pressure gradient in a direction substantially parallel to the longitudinal axis of the sampling portion. 
     The sampling portion of the biopsy device can include first and second components rotatable relative to each other. The second component can move relative to the first component when going from a first position in which sampling portion is open to a second position in which the sampling portion is closed. A wall of the second component can have an edge configured to cut tissue. 
     The second component can include at least one orifice that provides fluid communication between an interior of the sampling portion and the first device. The biopsy device can also include a handpiece and a cannula. The cannula can have proximal end and distal ends. The proximal end can be operably coupled with the handpiece and the distal end can be operably coupled with the sampling portion. The sampling portion can include first and second components rotatable relative to each other. The second component can be partially disposed in the cannula and rotatably coupled to the cannula. The first component can be integral with the cannula. The biopsy device can have a dead space of less than about five millimeters (e.g., less than about four millimeters, less than about three millimeters, less than about one millimeter). 
     In an additional aspect, the invention features a biopsy device that includes a handpiece, a cannula, and a sampling portion. The cannula is operatively coupled with the handpiece and has a distal end. The sampling portion of the biopsy device is operatively coupled with the distal end of the cannula. The sampling portion includes a first component and a second component that is moveable relative to the first component. In a first position the sampling portion is closed and in a second position the sampling portion is open. 
     Embodiments can include one or more of the following features. 
     When in the first position, the first component and the second component can form a substantially closed portion having a tubular region and a tip region. When in the second position, the first component can be at least partially disposed within the second component. The first component can include a first portion having a semi-circular cross-section and a second portion extending at a non-right angle from the first portion of the first component to form a tip. The second component can include a first portion having a semi-circular cross-section and a second portion extending at a non-right angle from the first portion of the second component to form a tip. The first portion of the first and second portions of the first component can include an edge configured to cut tissue. 
     The biopsy device can include a first device configured to form a pressure gradient in the biopsy device. The first device can be in fluid communication with at least one orifice in the sampling portion so that, during use of the first device, the first device forms a pressure gradient in a direction non-parallel to a longitudinal axis of the sampling portion. The biopsy device can include a second device configured to form a pressure gradient in the biopsy device. The second device can be operatively coupled with the sampling portion so that, during use of the second device, the second device forms a pressure gradient in a direction substantially parallel to the longitudinal axis of the sampling portion. 
     The biopsy device can have a dead space of less than about five millimeters (e.g., less than about four millimeters, less than about three millimeters, less than about one millimeter). 
     In an additional aspect, the invention features a biopsy device that includes a sampling portion having two components that are rotatable relative to each other. The biopsy device has a dead space of less than about five millimeters (e.g., less than about four millimeters, less than about three millimeters, less than about one millimeter). 
     Embodiments can have one or more of the following advantages. 
     In some embodiments, a biopsy device can be designed to increase the sample size of a sample retrieved by biopsy device. This can be advantageous because a larger sample provides more tissue for testing and/or fewer samples may be required. 
     In certain embodiments, a biopsy device can be designed to reduce the dead space of the biopsy device. This can be beneficial because a reduction in dead space can allow for more accurate positioning of the biopsy device. 
     In some embodiments, a biopsy device can be configured to form a pressure gradient in a sampling portion. This can be desirable because it can, for example, increase the sample size of a sample retrieved by the biopsy device. 
     Features and advantages are in the description, drawings, and claims. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  illustrates the delivery of a portion of a biopsy device into the body of a subject. 
         FIG. 2  is a side view of an embodiment of a biopsy device. 
         FIG. 3A  is a side cross-sectional view of an embodiment of a biopsy device. 
         FIG. 3B  is a cross-sectional view of the biopsy device of  FIG. 3A , taken along line  3 B- 3 B in  FIG. 3A . 
         FIG. 4A  is a side cross-sectional view of an embodiment of a biopsy device. 
         FIG. 4B  is a cross-sectional view of the biopsy device of  FIG. 4A , taken along line  4 B- 4 B in  FIG. 4A . 
         FIG. 5  is a side cross-sectional view of an embodiment of a biopsy device. 
         FIG. 6  is a cross-sectional view of an embodiment of a biopsy device and an enlarged region of a portion of the biopsy device. 
         FIG. 7  is a partial side cross-sectional view of a portion of a biopsy device. 
         FIG. 8A  is a perspective view of a component of the biopsy device. 
         FIG. 8B  is a cross-sectional view of the component of  FIG. 8A , taken along line  8 B- 8 B in  FIG. 8A . 
         FIG. 8C  is a cross-sectional view of the component of  FIG. 8A , taken along line  8 C- 8 C in  FIG. 8A . 
         FIGS. 9A-9E  illustrate the use of a biopsy device to sample tissue. 
         FIG. 10  is a perspective view of a component of the biopsy device. 
         FIG. 11  is a perspective view of a component of the biopsy device. 
         FIG. 12  is a cross-sectional view of a portion of a biopsy device. 
         FIG. 13  is a partial side cross-sectional view of a portion of a biopsy device. 
         FIGS. 14A-14D  illustrate the use of a biopsy device to sample tissue. 
         FIG. 15A  is a cross-sectional view of the biopsy device. 
         FIG. 15B  is a cross-sectional view of the biopsy device. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows biopsy device  10  being used in the body  20  of a subject  22 . As shown in  FIG. 1 , distal end  12  of biopsy device  10  is inserted into body  20 . Biopsy device  10  can be used, for example, to obtain specimens of soft tissue (e.g., lung, kidney, liver, breast, thyroid, adrenal glands, endometrial, muscle, myocardial, and lymphatic), to obtain specimens of hard lesions (e.g., hard cancerous lesions, malignant tumors such as lipomas and liposarcoma), and to obtain specimens of bone. As described below, during use of biopsy device  10 , biopsy device  10  is activated which causes biopsy device  10  to dissect a specimen. 
     As shown in  FIG. 2 , biopsy device  10  includes a handpiece  30 , a cannula  40 , and a sampling portion  50 . Handpiece  30  includes an activation button  32  which can be used to actuate sampling portion  50  between an open position and a closed position (as described below). A proximal end  42  of cannula  40  is connected to a distal end of handpiece  30 . Cannula  40  is generally a hollow sheath, e.g., made of stainless steel. Sampling portion  50  of biopsy device  10  is connected to a distal end  44  of cannula  40 . Sampling portion  50  includes a pointed distal end  52 . During use, sampling portion  50  and at least a portion of cannula  40  are inserted into a subject (e.g., a human subject) to retrieve a specimen. 
       FIGS. 3A-B  and  4 A-B show sampling portion  50  of biopsy device  10  in the closed and open positions, respectively. Biopsy device  10  can be actuated between the closed and open positions in order to retrieve a sample. For example, in some embodiments, the biopsy device  10  is placed in the closed position during insertion. Since the biopsy device  10  is in the closed position upon insertion, the biopsy device  10  is actuated to the open position after insertion. Tissue is drawn into the sampling portion of biopsy device  10  (e.g., via suction) and the biopsy device  10  is actuated from the open position to the closed position to cut the tissue. 
     Sampling portion  50  includes an inner component  60  and an outer component  70 . Inner component  60  is moveable relative to outer component  70 . For example, inner component  60  can rotate about an axis  80  relative to outer component  70 . In the closed position, outer component  70  and inner component  60  form a tubular region  52  and a tip region  54  (e.g., a cone-shaped tip region). In the open position, inner component  60  is disposed within outer component  70  forming a sampling region  56 . Inner component  60  includes a sharp edge  65  that is configured to sever tissue when inner component  60  is rotated from the open position to the closed position. 
     Outer component  70  includes a tubular region  72  and a tip region  74 . Tubular region  72  includes a distal end connected at an angle with tip region  74  and a proximal end connected to cannula  40  ( FIG. 2 ). Outer component  70  can be integral with cannula  40 . For example, in some embodiments, outer component  70  and cannula  40  can be formed as a unitary piece. In some additional embodiments, outer component  70  and cannula  40  can be formed as separate pieces and bonded together (e.g., outer component  70  can be welded to cannula  40 ). 
     Similarly, inner component  60  includes a tubular region  62  and a tip region  64 . Tubular region  62  includes a distal end connected at an angle with tip region  64  and a proximal end moveably coupled to cannula  40 . 
     Inner component  60  can be moveably coupled (e.g., rotatably coupled) to cannula  40  using any desired method. In certain embodiments, inner component  60  is rotatable by from about 170° to about 190° (e.g., about 180°) such that edge  65  can completely sever tissue when rotating between the open position and the closed position. 
     Edge  65  is present on both tubular region  62  and a tip region  64  of inner component  60 . When rotated between the open and closed positions, edge  65  severs tissue in both tubular region  52  and tip region  54  of biopsy device  10 . Providing edge  65  along both tubular region  62  and a tip region  64  of inner component  60  can provide various advantages such as, for example, increasing the sample size of a sample retrieved by biopsy device  10  and/or reducing the dead space (e.g., the length of device  10  that extends beyond the portion of tissue being sampled) of biopsy device  10 . 
     As shown in  FIGS. 3B and 4B , tubular region  72  of outer component  70  and tubular region  62  of inner component  60  are generally curved in shape, for example semi-circular. Tubular region  72  includes an inner wall  77  and an outer wall  76 . The diameter, d 1 , of tubular region  72  (measured as the distance between the inner walls at the opening of tubular region  72 ) can be selected as desired. In some embodiments, diameter d 1  of tubular region  72  can be at least about 0.5 millimeter (e.g., at least about 1 millimeter, at least about 3 millimeters, at least about 5 millimeters, about 7 millimeters, about 10 millimeters, about 12 millimeters) and/or at most about 15 millimeters (e.g., at most about 12 millimeters, at least most 10 millimeters, at most 7 millimeters, at most 5 millimeters, at most 3 millimeters). 
     Tubular region  62  includes an inner wall  67  and an outer wall  66 . The diameter (d 2 ) of tubular region  62  (measured as the distance between the inner walls at the opening of tubular region  62 ) can be selected as desired. For example, diameter d 2  can be selected based on a desired sample size. In some embodiments, diameter d 2  of tubular region  62  can be at least about 0.5 millimeter (e.g., at least about 1 millimeter, at least about 3 millimeters, at least about 5 millimeters, about 7 millimeters, about 10 millimeters, about 12 millimeters) and/or at most about 15 millimeters (e.g., at most about 12 millimeters, at least most 10 millimeters, at most 7 millimeters, at most 5 millimeters, at most 3 millimeters). 
     In general, diameter d 2  is less than diameter d 1 . The difference between diameter d 2  and diameter d 1  allows inner component  60  to fit within outer component  70  when biopsy device  10  is in the open position ( FIG. 4A ). For example, the difference between diameter d 2  and diameter d 1  can be from about 1 millimeter to about 10 millimeters (e.g., from about 0.2 millimeter to about 0.8 millimeter, from about 0.4 millimeter to about 0.6 millimeter, about 3 millimeters, about 5 millimeters, about 7 millimeters). In the open position, inner component  60  is disposed within outer component  70  such that inner wall  77  of tubular region  72  is adjacent to outer wall  66  of tubular region  62 . In the closed position, inner component  60  and outer component  70  form a closed structure. 
     As described above, tip region  74  of outer component  70  and tip region  64  of inner component  60  can be adapted to penetrate tissue (e.g., in the body of a subject). Tip region  74  is angled relative to tubular region  72 . For example, tip region  74  can be disposed at an angle θ 1  relative to tubular region  72  where θ 1  is greater than about 90° and less than about 180°. In some embodiments, θ 1  is from about 110° to about 160° (e.g., from about 120° to about 150°, from about 130° to about 140°, from about 133° to about 137°, about 135°). Generally, tip region  74  can be connected to tubular region  72  using any desired method. In some embodiments, tip region  74  and tubular region  72  may be formed as a unitary piece. In certain embodiments, tip region  74  and tubular region  72  may be separately formed and then bonded together. 
     Tip region  64  is angled relative to tubular region  62 . For example, tip region  64  can be disposed at an angle  0   2  relative to tubular region  62  where θ 2  is greater than about 90° and less than about 180°. Preferably, θ 2  is from about 110° to about 160° (e.g., from about 120° to about 150°, from about 130° to about 140°, from about 133° to about 137°, about  135 °). Generally, θ 2  is approximately the same as θ 1  such that in a closed position ( FIG. 3A ) tip region  74  and tip region  64  form a closed, pointed tip region  54 . Tip region  64  can be connected to tubular region  62  using any desired method. In some embodiments, tip region  64  and tubular region  62  may be formed as a unitary piece. In certain embodiments, tip region  64  and tubular region  62  may be separately formed and then bonded together. 
     As shown in  FIG. 5 , tubular region  62  of inner component  60  has a length L 1  and tip region  64  of inner component  60  has a length L 2 . Tubular region  72  of outer component  70  has a length L 3  and tip region  74  of outer component  70  has a length L 4 . Lengths L 1 , L 2 , L 3 , and L 4  can be selected as desired. 
     In certain embodiments, length L 1  can be at least about one millimeter (e.g., at least about three millimeters, at least about five millimeters, at least about seven millimeters, at least about ten millimeters, at least about fifteen millimeters), and/or at most about twenty millimeters (e.g., at most about fifteen millimeters, at most about ten millimeters, at most about seven millimeters, at most about five millimeters, at most about three millimeters). In certain embodiments, length L 2  can be at least about one millimeter (e.g., at least about three millimeters, at least about five millimeters, at least about seven millimeters, at least about ten millimeters), and/or at most about fifteen millimeters (e.g., at most about ten millimeters, at most about seven millimeters, at most about five millimeters, at most about three millimeters). 
     In certain embodiments, length L 3  can be at least about one millimeter (e.g., at least about three millimeters, at least about five millimeters, at least about seven millimeters, at least about ten millimeters, at least about fifteen millimeters), and/or at most about twenty millimeters (e.g., at most about fifteen millimeters, at most about ten millimeters, at most about seven millimeters, at most about five millimeters, at most about three millimeters). In certain embodiments, length L 4  can be at least about one millimeter (e.g., at least about three millimeters, at least about five millimeters, at least about seven millimeters, at least about ten millimeters), and/or at most about fifteen millimeters (e.g., at most about ten millimeters, at most about seven millimeters, at most about five millimeters, at most about three millimeters). 
     In general, length L 1  is about the same as length L 3 . For example, in certain embodiments, the difference (L o ) between length L 1  and length L 3  can be at most about  2  millimeters (e.g., at most about 1.5 millimeters, at most about 1.25 millimeters, at most about 1.0 millimeter, at most about 0.75 millimeter, at most about 0.5 millimeter). In addition, length L 2  is about the same as to length L 4 . For example, in certain embodiments, the difference (L D ) between length L 2  and length L 4  can be at most about 2 millimeters (e.g., at most about 1.5 millimeters, at most about 1.25 millimeters, at most about 1.0 millimeter, at most about 0.75 millimeter, at most about 0.5 millimeter). 
     Since the length of inner component  60  and outer component  70  are about the same, the dead space (L D ) of biopsy device  10  is reduced. The dead space of biopsy device  10  refers to the length of device  10  that extends beyond the portion of tissue being sampled. As shown in  FIG. 5 , the dead space, L D , is the difference between the length of inner component  60  (L 1 +L 2 ) and the length of outer component  70  (L 3 +L 4 ). In certain embodiments, the dead space of biopsy device  10  is less than about ten millimeters (e.g., less than about seven millimeters, less than about five millimeters, less than about four millimeters, less than about three millimeters, less than about two millimeters, less than about one millimeter). 
     In some embodiments, a pressure gradient can be used to draw tissue into sampling portion  50  of biopsy device  10 . For example,  FIG. 6  shows an embodiment of biopsy device  10  in which biopsy device  10  includes a vacuum device  34  configured to form a pressure gradient in sampling portion  50 . Vacuum device  34  is in fluid communication with one or more orifices  90  located in inner component  60 . During use, vacuum device  34  applies a vacuum to orifices  90  such that the pressure gradient is formed in a direction non-parallel to the longitudinal axis  80  of sampling portion  50  (e.g., as shown in  FIG. 7 ). For example, in certain embodiments, the pressure gradient can be formed at an angle that is at least about 10° (e.g., at least about 25°, at least about 45°, at least about 60°, at least about 75°, at least about 85°) with respect to longitudinal axis  80 . In some embodiments, the pressure gradient can be at an angle that is substantially perpendicular (at least about 85° with respect to) longitudinal axis  80 . 
       FIG. 8A  shows a perspective view of inner component  60  of a biopsy device  10  which includes multiple orifices  90 .  FIGS. 8B and 8C  show cross-sectional views of inner component  60  at locations  8 B- 8 B and  8 C- 8 C, respectively. Inner component  60  includes multiple orifices  90  arranged along longitudinal axis  80  of inner component  60 . In order to form a pressure gradient, vacuum device  34  applies a vacuum to orifices  90 . For example, orifices  90  can be in fluid communication with vacuum device  34  by a hollow region  91  between inner wall  67  and outer wall  66  of inner component  60 . 
       FIGS. 9A-9E  illustrate the use of biopsy device  10 .  FIG. 9A  shows an exemplary sampling device in which inner component  60  includes multiple orifices (e.g., orifices  90   a,    90   b,    90   c,    90   d,    90   e,  and  90   f ). A pressure gradient can be formed in sampling portion  50  by applying a vacuum to orifices  90   a,    90   b,    90   c,    90   d,    90   e,  and  90   f  (as indicated by arrows  100 ). As shown in  FIG. 9B  the pressure gradient draws tissue  102  into sampling portion  50 . As tissue  102  is drawn into sampling portion  50 , portions of tissue  102  can come into physical contact with inner component  60 . When tissue  102  comes into contact with inner component  60 , tissue  102  can block one or more of the orifices (e.g., orifices  90   a,    90   b,    90   c,    90   d,    90   e,  and  900  which form the pressure gradient. As shown in  FIG. 9B , tissue  102  has prolapsed such that orifices  90   d  and  90   e  are covered. When orifices  90   d  and  90   e  become covered, the pressure gradient applied by the other orifices (e.g., orifices  90   a,    90   b,    90   c,  and  900  increases helping to draw additional tissue  102  into sampling portion  50  thereby increasing the sample size of tissue  102  ( FIG. 9C ). After the tissue  102  has been drawn into sampling portion  50 , inner component  60  is rotated relative to outer component  70  shearing the portion of tissue  102  that has been drawn into sampling portion  50  to form a tissue specimen  102 ′ ( FIG. 9D ). The tissue specimen  102 ′ is drawn into cannula  40  by applying a pressure gradient in a direction substantially parallel to longitudinal axis  80  of sampling portion  50  ( FIG. 9E ). 
     While in the example described above, orifices  90  were arranged along a longitudinal axis  80  of inner component  60 , orifices  90  can be arranged as desired. For example, multiple sets of orifices (e.g., two sets, three sets, four sets, five sets) can be arranged in a configuration offset from the longitudinal axis  80  by an angle θ. For example, θ can be from about 5° to about 80° (e.g., about 10°, about 15°, about 30°, about 45°, about 60°).  FIG. 10  shows an exemplary arrangement of two sets of orifices disposed at an angle θ of about +/−30 degrees from longitudinal axis  80 .  FIG. 11  shows an additional exemplary arrangement of orifices  90  in which orifices  90  are randomly spaced within inner component  60 . 
     While in the embodiments described above a hollow tube  91  was in fluid communication with the orifices, as shown in  FIG. 12 , in some additional embodiments, the entire region  98  between inner wall inner wall  67  and outer wall  66  of inner component  60  could be hollow. 
     In certain embodiments, as shown in  FIG. 13 , biopsy device  10  can include an additional pressure gradient applied in a direction substantially parallel to (at most about 5° with respect to) longitudinal axis  80  of sampling portion  50 . In embodiments that include pressure gradients in both parallel and non-parallel directions, the pressure gradient in the non-parallel direction ( FIG. 7 ) can be used to draw tissue into sampling portion  50  prior to severing the sample while the pressure gradient in the parallel direction ( FIG. 13 ) can be used to draw a severed sample into cannula  40  of biopsy device  10 . 
     While in some of the embodiments described above biopsy device  10  forms a pressure gradient to draw tissue into sampling portion  50 , in certain embodiments biopsy device  10  is devoid of a device that forms a pressure gradient in sampling portion  50 . For example,  FIGS. 14A-14D  illustrate the use of a biopsy device  10  without application of a pressure gradient. Prior to insertion of biopsy device  10  into the body, sampling portion  50  is placed in a closed position ( FIG. 14A ). Sampling portion  50  and at least a portion of cannula  40  are inserted into the subject&#39;s body such that sampling portion  50  extends into a tissue  102  ( FIG. 14B ). When sampling portion  50  is disposed in tissue  102 , tissue  102  is displaced from a relaxed position forming a pressure on the outer walls of sampling portion  50  as indicated by arrows  122 . Sampling portion  50  is actuated into an open position by rotation of inner component  60  ( FIG. 14C ). Upon rotation of inner component  60  into the open position, a portion of the tissue  102  prolapses into sampling portion  50 . Inner component  60  is subsequently rotated relative to outer component  70  such that edge  65  shears the portion of tissue  102  that had prolapsed into sampling portion  50  ( FIG. 14D ) thereby forming a tissue specimen  102 ′. 
     While certain embodiments have been described, other embodiments are possible. 
     For example, the components of biopsy device  10  described above can be formed by conventional injection molding techniques, e.g., of polycarbonate and/or ABS. 
     As a further example, in certain embodiments, sampling portion  50  and cannula  40  can be formed of stainless steel. 
     As a further example, in some embodiments, a medical kit can include a biopsy handpiece  30 , multiple cannulas  40  and sampling portions  50  (e.g., having different lengths). 
     As an additional example, in certain embodiments, a portion of the sampling portion  50  and/or cannula can be configured to cauterize tissue. For example, an electrocautery material can be added to a portion of sampling portion  50  (e.g., the tip) and an insulation can be placed on the remainder of sampling portion  50  and on cannula  40 . The electrocautery feature allows the biopsy device  10  to cauterize tissue and stop bleeding. 
     As an additional example, while embodiments described above (e.g., as shown in  FIGS. 3B and 4B ) describe an edge  65  that extends at an angle from inner wall  67  and outer wall  66  to form a sharp edge at a location between inner wall  67  and outer wall  66  of inner component  60 , other methods for forming the sharp edge  65  can be used. For example, as shown in  FIGS. 15A and 15B , the sharp edge  65  can extend from inner wall  67  to outer wall  66 . As described above, when rotated between the open and closed positions, edge  65  severs tissue in tubular region  52  and tip region  54  of biopsy device  10 . 
     As an additional example, in certain embodiments, both inner component  60  and outer component  70  can include a sharp edge that is configured to sever tissue when inner component  60  is rotated from the open position to the closed position. For example, as shown in  FIGS. 15A  and B, inner component  60  can include an edge  65  is present on both tubular region  62  and a tip region  64  of inner component  60  and outer component  70  can include an edge  75  that is present in tubular region  72  and a tip region  74  of inner component  70 . In some embodiments, edge  65  of component  60  can extend at an angle from inner wall  67  to outer wall  66  and edge  75  can extend at an angle from inner wall  77  to outer wall  76 . When rotated between the open and closed positions, edges  65  and  75  sever tissue in both tubular region  52  and tip region  54  of biopsy device  10 . 
     Other embodiments are in the claims.