Abstract:
A kit of parts for taking a biopsy sample from a hard tissue having a needle and a biopsy gun. The needle having an interior shaft and an exterior sleeve forming a tip for piercing hard tissue. The sleeve having a first attachment means and the shaft having a second attachment means complementary to the first attachment means. The biopsy gun having a sampling tip and a third attachment means that is complementary to the second attachment means. In operation, the biopsy gun is placed in the sleeve and secured by the third attachment means and when the gun is fired, a recoil is absorbed by the shaft.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a biopsy device (also referred to herein as a “biopsy gun”). In particular, the present invention relates to a biopsy gun used to take biopsy samples from a hard tissue such as a vertebral body. 
     2. Description of the Prior Art 
     It is often necessary to obtain a biopsy sample from a patient suspected of having a disease or disorder, such as deterioration of the vertebral body, cancerous tumours or pre-malignant conditions. For example, in vertebroplasty a percutaneous biopsy sample is extracted from the patient prior to the injection of a suitable cement to determine the cause of the deterioration of the vertebral body. 
     Biopsy samples of vertebral bodies can be taken using a combination of a biopsy needle and a biopsy gun. The needle is inserted into the tissue from which a sample is to be taken, and then the biopsy gun is inserted through the needle shaft to extract the biopsy sample. Generally, the biopsy gun contains an interior sleeve with an open section that receives the tissue sample and is coaxially, slidably engaged with an exterior sleeve. The exterior sleeve may be retracted or pulled back to expose the interior sleeve prior to the sampling and released to contain the sample within the open section. The exterior sleeve of the biopsy gun is connected to a spring or the like that biases the exterior sleeve over the interior sleeve. When the sleeve is pulled back, the spring is compressed and a catch will hold the sleeve to expose the interior sleeve. The sample is taken by releasing the catch which releases the spring causing the exterior sleeve to cover the interior sleeve and slice the tissue sample so that it falls into the open section of the interior sleeve. This action can cause the needle to recoil away from the body that the sample is being taken from. 
     Overall, it can be seen that conventional biopsy needles and guns for sampling verterbral bodies require a skilled operator to control the positioning of the needle and then control the operation of the biopsy gun while maintaining the position of the needle. This can be awkward for the operator. 
     Accordingly, it would be desirable to have a biopsy gun or device which facilitated obtaining the biopsy sample. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a novel biopsy gun which obviates or mitigates at least one of the above-mentioned disadvantages of the prior art. 
     Accordingly, in one of its aspects, the present invention-provides a kit of parts for obtaining a biopsy sample a subject, comprising: 
     a needle comprising an interior shaft coaxially disposed within and slidably engaged with respect to an exterior sleeve; the exterior sleeve comprising a first attachment means; the shaft having a second attachment means which cooperates with the first attachment means for releasable engagement of the shaft and the sleeve; and 
     a biopsy gun comprising a sampling tip and a third attachment means which cooperates with the first attachment means for releasable engagement of the biopsy gun and the exterior sleeve. 
     In another of its aspects, the present invention provides a biopsy gun for use with a needle having an interior shaft attached to a first attachment means and an exterior sleeve having a second attachment means for releasable engagement with the first attachment means, the gun comprising: 
     a sampling tip; and 
     a third attachment means which cooperates with the first attachment means to releasably engage the gun and the sleeve. 
     In another of its aspects, the present invention provides a kit of parts for taking a biopsy sample from a hard tissue, comprising: 
     a needle comprising an interior shaft coaxially disposed within and slidable with respect to an exterior sleeve, the needle comprising a first attachment element; 
     a biopsy gun comprising a second attachment element releasably engageable with the first attachment element of the needle. 
     Thus, an aspect of the invention relates to a kit of parts for taking a biopsy sample from a hard tissue. The kit contains a needle for piercing the hard tissue, with an interior shaft and an exterior sleeve, and a biopsy gun. The interior sleeve has a first attachment means at an end opposite to the tip and the shaft has a second attachment means. The second attachment means is complementary to the first attachment means for releasably securing the shaft to the sleeve. The biopsy gun has a sampling tip longer than the sleeve and a third attachment means substantially identical to the second attachment means, for releasably securing the gun to the sleeve such that when the gun is secured to the sleeve the sampling tip extends therepast and, when fired, a recoil is substantially absorbed by the shaft. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the present invention will be described with reference to the accompanying drawings, in which: 
     FIG. 1 illustrates an isometric view of a needle with an interior shaft and an exterior sleeve; 
     FIG. 2 illustrates an isometric view of the interior shaft of the needle in FIG. 1 removed from the exterior sleeve of the needle; 
     FIG. 3 illustrates an end view of the interior shaft of the needle in FIG. 1; 
     FIG. 4 illustrates a partial isometric view of the tip of the needle in FIG. 1; 
     FIG. 5 illustrates an isometric view of a biopsy gun receivable in the exterior sleeve of the needle of FIG. 1; 
     FIG. 6 illustrates an isometric view of a biopsy gun received with the exterior sleeve of the needle of FIG. 1; and 
     FIG. 7 illustrates an isometric view of a needle receivable in a vertebral body. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to FIGS. 1 to  7 , a needle according to an embodiment of the present invention is indicated generally at  20 . Needle  20  is preferably used for insertion into a vertebral body or other hard tissue. In a present embodiment needle  20  is surgical grade stainless steel but other suitable materials can be used, as will occur to those of skill in the art. Needle  20  generally consists of a sleeve  22  and a shaft  24  receivably removable within sleeve  22 . As shown in FIG. 7, shaft  24  is receivable within sleeve  22  for insertion of needle  20  into a vertebral body  26  via a percutaneous route. Shaft  24  is removable from sleeve  22  to facilitate the engagement of a biopsy gun  54 , shown in FIG.  5 . 
     Sleeve  22  is a hollow cylinder with an outlet  28 . Sleeve  22  is cylindrically centred about an axis  30 . In a present embodiment, the cross-sectional area of sleeve  22  is not reduced at outlet  28 , and has four substantially equal, inwardly bevelled surfaces  32  defining outlet  28 . Each surface  32  is bevelled toward axis  30 . Thus, sleeve  22  has four sharp points  34  at outlet  28 . Each sharp point  34  is present at each intersection of two bevelled surfaces  32 . Each bevelled surface  32  is at substantially the same angle to axis  30 . Preferably, each bevelled surface  32  is at an angle of from about 15° to about 75°. More preferably, each bevelled surface  32  is at an angle of from about 30° to about 60°. It is presently preferred however, that each bevelled surface  32  is at an angle of about 45° to axis  30 . 
     Sleeve  22  is fixed to a first handle  36 , at the opposing end to outlet  28 , for grasping by the operator. Sleeve  22  can be fixed to first handle  36  by friction fit or other means as will occur to those of skill in the art. Preferably, first handle  36  is a molded polymer but other materials and forming processes can be used. First handle  36  can be any shape suitable for grasping by an operator. According to a present embodiment, first handle  36  has two wings  38  for grasping. 
     Shaft  24  is generally cylindrical with a tip  42 . Tip  42  has four substantially equal, inwardly bevelled faces  48 . Each face  48  is bevelled at substantially the same angle as bevelled surfaces  32 . Thus, all four bevelled faces  48  intersect at a leading point  44  that protrudes from sleeve  22 . When shaft  24  is received within sleeve  22 , shaft  24  can be oriented such that each of bevelled faces  48  is aligned with one of bevelled surfaces  32 . The bevel angle is substantially identical between shaft  24  and sleeve  22 , thus there is no step from tip  42  to sleeve  22 , to present four continuous bevelled faces from sleeve  22  to tip  42 . 
     Shaft  24  is fixed to a second handle  50  for grasping by the operator at the opposing end to tip  42 . Shaft  24  can be fixed to second handle  50  by friction fit or other means as will occur to those of skill in the art. Preferably second handle  50  is a molded polymer but other materials and forming processes can be used. 
     First handle  36  comprises first tab  40 . Second handle  50  comprises second tab  52 . First tab  40  is releasably engageable with second tab  52  of handle  50 . In the present embodiment, first tab  40  is an inwardly resilient biased tab. Second tab  52  is a complementary biased tab which engages first tab  40  when shaft  24  is received within sleeve  22 . Other suitable attachment means can also be used, as will occur to those of skill in the art, such as a luer lock and other interference fit connection schemes. 
     Referring now to FIG. 5, a biopsy gun is indicated generally at  54 . Biopsy gun  54  generally consists of a body portion  56  and a sampling tip  58 . Sampling tip  58  is receivable within sleeve  22  of needle  20  for insertion of sampling tip  58  into a body  26  via percutaneous route. 
     Sampling tip  58  has a sheath  60  and an insert  62  receivably removable within sheath  60 . Insert  62  has a tip  64  and a cavity  66 , located adjacent to tip  64 , for receiving hard tissue. Sheath  60  is a hollow cylinder with an outlet  68 . Sampling tip  58  is fixed to body portion  56  at the opposing end to tip  64 . Sampling tip  58  can be fixed to body portion  56  by friction fit or other means as will occur to those of skill in the art. 
     Body portion  56  consists of a third handle  70 , an actuator  72  and a third tab  74 . Third handle  70  can be any shape suitable for grasping by an operator. According to a present embodiment third handle  70  has two cyclical hollow portions  76  for receiving the fingers of an operator. 
     Third tab  74  is operable to releasably attach to first tab  40  of first handle  36 . In the present embodiment, third tab  74  is a complementary biased tab which engages first tab  40  when biopsy gun  54  is received within sleeve  22 , as shown in FIG.  6 . 
     In a present embodiment, actuator  72  is retractable and integrally coupled to sheath  60 . Actuator  72  is spring loaded and is operable to slidingly retract sheath  60  along insert  62 , in the opposite direction from tip  64 , for uncovering cavity  66  when sampling tip  58  is releasably engaged in vertebral body  26 . When actuator  72  is retracted, sheath  60  is moved along insert  62  away from tip  64  and held in a locked position. This motion causes cavity  66  to be revealed and operable to receive hard tissue. 
     When actuator  72  is released sheath  60  is projected along insert  62  until it reaches tip  64 . This motion causes cavity  66  to be covered by sheath  60 . 
     The operation of biopsy gun  54  will now be described with reference to the foregoing and, particularly, attached FIGS. 5-7. Needle  20  is inserted into vertebral body  26  via a percutaneous route. Second tab  52  is detached from first tab  40  and shaft  24  is slidably removed from sleeve  22 . Sleeve  22  is now operable to receive biopsy gun  54 . Biopsy gun  54  is inserted into vertebral body  26  by slidably engaging sampling tip  58  in sleeve  22 . Third tab  74  is releasably attached to first tab  40 . 
     Once biopsy gun  54  has been inserted in vertebral body  26 , actuator  72  is retracted from body portion  56  and sheath  60  is retracted along insert  62  away from tip  64 . When actuator  72  is locked in a retracted position it holds sheath  60  in a position that reveals cavity  66  on insert  62 . Once revealed, cavity  66  is operable to receive hard tissue. Actuator  72  may then be released and sheath  60  is fired along insert  62  to tip  64 . As sheath  60  passes over cavity  66  the edge of outlet  68  slices through the hard tissue. A sample of hard tissue remains enclosed in cavity  66 . 
     In order to remove biopsy gun  54  from vertebral body  26 , third tab  74  is detached from first tab  40 . Biposy gun  54  is now operable to slidingly move out of vertebral body  26  through sleeve  22 . The hard tissue sample can be removed from cavity  66  by repeating the above method of retracting actuator  72 . 
     While the embodiment discussed herein is directed to a particular implementation of the invention, it will be apparent that variations of this embodiment are within the scope of the invention. For example, first tab, second tab and third tab may be other complementary locking devices, such as male and female luer locks. First handle, second handle and third handle may be any shape suitable to be grasped and securely held by an operator. The actuator may be any device suitable for retracting and firing the sheath along the insert and may work in combination with the third handle so that the third handle is spring loaded and operable to retract the sheath and the actuator is coupled to the third handle and is operable to release the sheath. Thus, while the present invention has been described with reference to preferred and specifically illustrated embodiments, it will of course be understood by those skilled in the arts that various modifications to these preferred and illustrated embodiments may be made without departing from the spirit and scope of the invention. 
     All publications, patents and patent applications referred to herein are incorporated by reference in their entirety to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety.