Abstract:
A biopsy device includes a housing and at least one biopsy mechanism moveably connected to the housing. The biopsy can be provided on a biopsy arm. An actuator moves the biopsy arm and operates the biopsy mechanism. The biopsy arms with the biopsy mechanisms are preferably removable from the housing, such that the housing can be used again for subsequent biopsy procedures.

Description:
FIELD OF THE INVENTION 
   This invention relates generally to medical instrumentation, and more particularly to biopsy devices. 
   BACKGROUND OF THE INVENTION 
   Biopsy devices are used to obtain tissue samples, usually for purposes of performing testing on these samples. In order to obtain a biopsy sample, the biopsy device must be inserted into the body to reach the tissue for which the biopsy is to be taken. The device must be positioned next to the tissue, the sample taken, and the device removed. Some biopsy protocols require multiple samples to be taken. In the case of a body canal, samples from different positions on the circumference of the canal are sometimes required for each axial position along the canal length. This can require multiple devices if sterility and sample integrity are to be maintained, or multiple procedures if more than one biopsy site is required to be sampled. 
   It is difficult to maintain the stability and position of a biopsy device upon insertion into the body. Biopsy procedures usually involve small incisions such that manipulation of the device at the point of the biopsy is not directly possible. It is possible for the biopsy sample to become dislodged from the biopsy device during removal of the device from the body. Secure retention of the sample is necessary to avoid repeating the process. 
   SUMMARY OF THE INVENTION 
   A biopsy device includes a housing and at least one biopsy mechanism connected to the housing. The biopsy mechanism can be provided on a biopsy arm that is connected to the housing. An actuator is provided for moving the biopsy arm and operating the biopsy mechanism. 
   The biopsy mechanism can comprise jaws adapted to engage and remove a biopsy sample. The jaws can be biased to an open position. The actuator can contact the jaws, a cam, or other structure connected to the jaws, such that movement of the actuator opens the jaws. 
   The actuator can comprise a moveable plunger. The housing can include an open interior and the plunger can be provided in the open interior. Movement of the plunger contacts the cam or other structure to operate the biopsy mechanism. Movement of the plunger can also move the biopsy arm radially outward relative to the housing. This movement will position the biopsy mechanism against the tissue to be sampled. Thus, a single stroke of the actuator can move the biopsy mechanism into position and operate the biopsy mechanism to take the sample. Gripping structure can be provided on the housing and the plunger so as to facilitate relative movement of the plunger within the housing. 
   Movement of the actuator in a first direction can force the biopsy arm radially outward and causes the biopsy mechanism to open. Movement of the actuator in a second direction causes the biopsy arm to move radially inward and the biopsy mechanism to close. Alternatively, the actuator can be constructed such that movement in one direction will in one position open the biopsy mechanism, and movement to another position, but in the same direction, will close the biopsy mechanism. 
   The biopsy mechanism can be biased to an open position or a closed position. A cam can be operatively connected to the biopsy mechanism. Contact between the actuator and the cam causes the biopsy mechanism to open or close against the biasing. The biopsy mechanism should be in the closed position prior to the biopsy arm moving radially inward such that the sample will be securely retained. 
   In a preferred embodiment, a plurality of biopsy arms are provided. A plurality of radially disposed biopsy arms can be spaced about an end of the housing. A first end of each arm can be connected to the housing. Each biopsy arm has a biopsy mechanism such that movement of the actuator actuates each of the biopsy arms and the respective biopsy mechanism. The biopsy mechanism can be provided at or near an opposing end of the biopsy arm. Two or more arms are preferred. Four or more radially disposed arms permit sampling about the circumference of a canal or orifice, such as the esophagus. 
   The biopsy arms can be provided on a head that is removably attached to the housing. In this manner, the head can be removed after the biopsy is performed and the housing and related actuator mechanism can be refitted with another head for taking another sample. The removed head with the biopsy samples is then processed to remove the samples for laboratory analysis. 
   A biopsy method includes the steps of providing a biopsy device with a housing and at least one biopsy mechanism connected to the housing. Structure is provided for moving the biopsy mechanism and actuating the biopsy mechanism. The biopsy mechanism can be provided on a biopsy arm that is connected to the housing. The device is inserted adjacent to tissue and the actuator is manipulated in order to move the biopsy mechanism into position and to operate the biopsy mechanism to obtain a sample. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     There are shown in the drawings embodiments which are presently preferred, it being understood however, that the invention is not limited to the precise arrangements and instrumentalities shown, wherein: 
       FIG. 1  is a perspective view of a biopsy device according to the invention. 
       FIG. 2  is a cross section of a biopsy device according to the invention, and in a first mode of operation. 
       FIG. 3  is a cross section depicting a second mode of operation. 
       FIGS. 4(   a )–( c ) are cross sections depicting successive steps in a biopsy procedure according to the invention. 
       FIGS. 5(   a )–( b ) are cross sections depicting the operation of a biopsy mechanism according to the invention. 
       FIGS. 6(   a )–( b ) are enlarged cross sections of the biopsy mechanism of  FIG. 5  as used during a biopsy procedure. 
       FIGS. 7(   a )–( b ) are exploded perspective views illustrating an alternative embodiment of the invention. 
       FIGS. 8(   a )–( c ) are cross sections illustrating a biopsy procedure utilizing an alternative biopsy mechanism according to the invention. 
       FIGS. 9(   a )–( b ) are cross sections illustrating the operation of an alternative embodiment. 
       FIG. 10  is a cross section illustrating a gripping device of the alternative embodiment of  FIG. 9 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A biopsy device  10  according to the invention is shown in  FIG. 1 . The biopsy device  10  includes a housing  12  and at least one biopsy mechanism  18 . The housing  12  can be of any suitable construction. The biopsy mechanism  18  can be provided on a biopsy arm  14 . Any number of biopsy arms  14  can be provided, however, at least two and preferably at least four biopsy arms  14  are preferred. 
   An actuator is provided for moving the biopsy mechanism outward relative to the housing  12  and operating the biopsy mechanism  18 . The actuator can be a single mechanism or multiple mechanisms. Any suitable actuator mechanism(s) can be utilized. In one embodiment, the actuator comprises a plunger  22  which is moveable within an open interior  26  of the housing  12 . Suitable structure such as handle  23  can be provided for manipulating the plunger  22 . Movement of the actuator operates the biopsy mechanism  18  as shown in  FIGS. 2–3 . In one embodiment, the plunger  22  is operable to contact the biopsy mechanism  18  in such a manner as to operate the biopsy mechanism  18 . A cam  40  can be associated with the biopsy mechanism  18 . The movement of the plunger  22  contacts the cam  40  ( FIG. 3 ) to operate the biopsy mechanism  18 . 
   The biopsy mechanism  18  can be of any design that is suitable to remove a biopsy sample when actuated. The biopsy mechanism  18  is provided by suitable structure such that the biopsy mechanism is moved into position and operated to take the sample, preferably in a single action. In one design, the biopsy mechanism  18  comprises forceps  36 . As shown in  FIGS. 4–6 , the forceps  36  are associated with suitable structure, such as cam  40 , to operate the forceps  36 . Biasing, such as spring  44 , can be provided to bias the forceps  36  to a normally-closed position. Movement of the plunger  22  from a position within the housing  12  as shown in  FIG. 5(   a ) to the position shown in  FIG. 5(   b ) causes the plunger  22  to contact the cam  40 . The cam  40  is moved within the cam seat  52  from the position shown in  FIG. 5(   a ) to the position shown in  FIG. 5(   b ) against the action of the spring  44 . The forceps  36  are moved outward from the biopsy arm  14  and open through the operation of suitable structure such as spring  58  as shown in  FIG. 6(   a ). The biopsy arms  14  can be provided with a substantially wedge-shaped portion  55  as shown in  FIG. 4(   a ). Movement of the plunger  22  causes the plunger  22  to contact the wedge portion  55  to cause the biopsy arms  14  to move outward as shown in  FIGS. 4(   a )–( c ). Retraction of the plunger  22  causes the return of the forceps  36  from the open position shown in  FIG. 4(   b ) to the closed position and inward movement of the biopsy arms  14 , as shown in  FIG. 4(   c ). Other structure for moving the biopsy arms  14  and biopsy mechanisms  18  outward and inward are alternatively possible. 
   In operation, the biopsy device  10  is positioned in a portion of the body such as canal  50 , although it will be appreciated that the biopsy device  10  of the invention can be utilized to biopsy tissues throughout the body. The plunger  22  is initially in the retracted position. When the biopsy device  10  has been properly positioned, movement of the plunger  22  causes the plunger  22  to contact wedge portions  55  of the biopsy arms  14  to move the biopsy arms  14  radially outward toward the walls of the canal  50  as shown in  FIG. 4(   b ). The plunger  22  also contacts the cam  40  to cause the forceps  36  to move from the normally-closed position to the open position. Thus, the biopsy mechanisms  18  are centered and forced toward the walls of the canal  50  and are opened for taking a sample. The biopsy device  10  of the invention permits, in one action, the outward movement of the biopsy arms  14  and the operation of the biopsy mechanism  18 . Upon retraction of the plunger  22 , the plunger  22  is removed from contact with the cam  40  which causes the forceps  36  to close under the action of the biasing spring  44 . A tissue sample  54  is removed by the forceps  36 . Also, retraction of the plunger  22  permits the biopsy arms  14  to move radially inward and away from the walls of the canal  50 , as shown in  FIG. 4(   c ). This will permit retraction of the biopsy device  10  whereupon the biopsy device  10  can be removed and the sample  54  can be obtained. The retraction of the plunger  22  closes the forceps  36  before the retraction of the plunger  22  causes significant inward movement of the biopsy arms  14 , such that the sample  54  is removed before the biopsy mechanism  18  is moved away from the tissue. 
   In some biopsy protocols, it is necessary to repeatedly biopsy in incremental lengths. For example, in a biopsy for Barretts Metaplasia (cancer of the esophagus), the protocol requires that a biopsy be taken every 5–20 mm. The repetition of the sampling can be tedious and time consuming. The biopsy device  10  according to the invention permits the sampling of the esophageal tissue about the circumference of the esophagus in a single action. Further, according to another embodiment of the invention, the removal of the biopsy sample  54  can be readily obtained. In this embodiment, shown in  FIGS. 7(   a )–( b ), the biopsy arms  14  and biopsy mechanisms  18  are provided on a head  60 . The head  60  is removably connected to the housing  12 . The connection can be made by any suitable structure, such as the interlocking tongue  61  and groove  63  structure that is shown. Upon the taking of a biopsy sample  54 , the biopsy device  10  is removed from the body and the head  60  is disconnected from the housing  12 . The biopsy sample  54  can then be removed by manipulating the head  60  on a removal device  64 . The removal device  64  can have a plunger  67  which is inserted into the head  60  to contact the biopsy mechanisms  18  to cause the mechanisms to open and release the samples  54 . The head  60  can then be discarded or cleaned and sterilized for further use. 
   The operation of an alternative embodiment of a biopsy mechanism according to the invention is shown in  FIGS. 8(   a )–( c ). The biopsy mechanism  78  is provided in a suitable seat in the biopsy arm  14 . Spring arms  86  are held open by contact with a piston  90 . Inward protruding portions  94  are contacted by a cross-piece  98  of the piston  90  to retain the spring arms  86  in the open position shown in  FIG. 8(   a ). The biopsy arm  14  is then forced against the tissue  100 , as by movement of the plunger  22  which wedges the biopsy arms  14  outward. Outward movement of the biopsy arms  14  causes end  104  of piston  90  to contact the tissue  100 , which forces the crosspiece  98  of the piston  90  away from the inward protruding portions  94  of the spring arms  86 , as shown in  FIG. 8(   b ). The spring arms  86  then spring closed, and a sample  108  is removed from tissue  100 . Retraction of the plunger  22  causes the piston  90  to retract through an opening  112 , the spring arms  86  to close securely, and the sample  108  to be secured between the spring arms  86 . This position is shown in  FIG. 8(   c ). The device can then be removed from the body to retrieve and process the biopsy samples. 
   There is shown in  FIGS. 9–10  an alternative embodiment comprising a gripping device  110  for securing the biopsy arms  14  to the surrounding tissue so as to facilitate the taking of a sample. The gripping device  110  includes suitable structure for gripping the tissue such as a projection  114  having a sharp end. The projection  114  is movable in an opening  128 . In one embodiment, the projection  114  is mounted on a carrier  122  which is pivotally mounted to biopsy arm  14  by pin  124 . Suitable biasing such as spring  126  can bias the projection  114  to a retracted position. Movement of the plunger  22  contacts end  130  of projection  114  as the plunger moves from the retracted position shown in  FIG. 9(   a ) to the extended position shown in  FIG. 9(   b ). As the biopsy arm  14  is thereby moved outward, the projection  114  is extended and the sharp end enters the surrounding tissue to secure the biopsy arm  14  in position while the biopsy is taken. The biopsy mechanism can be as previously described including forceps  36 , cam  40  and spring  44 , or can be of an alternative construction. Upon retraction of the plunger  22 , the forceps  36  will close prior to retraction of the projection  114  such that the biopsy sample will be removed before the surrounding tissue is released. 
   In an alternative embodiment, the biopsy device  10  permits the outward movement of the biopsy arms  14 , operation of the biopsy mechanisms  18 , followed by the closing of the biopsy mechanisms  18  and radially inward movement of the biopsy arms  14 , in a single action, that is, without retraction of the plunger  22 . Such a device could be provided with suitable grooves or openings on the sides of the plunger  22  to permit the biopsy mechanisms  18  and biopsy arms  14  to retract into the sides of the plunger  22  when the plunger  22  has been moved forward a given distance. 
   Although the invention has been described with reference to a device with biopsy arms  14 , the invention is not limited in this regard. The biopsy mechanisms  18  can be provided on other structure or on the housing  12 , so long as suitable structure is provided to cause the outward movement of the biopsy mechanisms  18  upon actuation of the device. 
   The biopsy device  10  according to the invention can be made from any suitable material. Also, the device can be made in a variety of different dimensions and designs without departing from the spirit or essential attributes of the invention. Accordingly, reference should be had to the following claims, rather than to the foregoing specification, as defining the scope of the invention.