Length detection system for biopsy device

Abstract

A biopsy device for harvesting tissue samples from a body of a living being, e.g. in percutaneous aspiration biopsy, includes a handle unit, a hollow needle comprised in a disposable unit, which is releasably attached to the handle unit, and a sample-receiving device, which is movable in the hollow needle between two positions. Tissue is severed when the sample-receiving device is in a first one of the positions, and the severed tissue sample is ejected from the sample-receiving device in a second one of the two positions. A control system is provided for controlling movement of the sample-receiving device and for arresting the sample-receiving device in the second position. The distance between the two positions and/or a length of the hollow needle may be detectable in a calibration cycle, which is automatically initiated upon attachment of the disposable unit to the handle unit. The disposable unit may include electronic memory means for communicating with the control system.

1 - 17 . (canceled) 
     
     
         18 . A disposable unit for a biopsy device comprising:
 a needle having a distal cutting edge;   a tissue device having a cavity, the tissue device movable in the needle between an extended position and a retracted position;   a transport device that moves the tissue device between the extended position and the retracted position, wherein the transport device includes:
 an elongate element having a distal end connected to the sample device and teeth; 
 a gear engaged with the teeth; 
   and
 a mechanism that coils the elongate element as the tissue device moves from the extended position to the retracted position, 
   wherein   in the extended position the cavity projects from a needle distal end, and   in the retracted position the cavity sits proximal to the needle distal end.   
     
     
         19 . The disposable unit of  claim 18  wherein the mechanism that coils sits at a proximal end of the disposable unit proximal to the retracted position. 
     
     
         20 . The disposable unit of  claim 18  wherein the teeth are regularly spaced. 
     
     
         21 . The disposable unit of  claim 18  comprising a joint rotatably connected between the tissue device and the elongate element. 
     
     
         22 . The disposable unit of  claim 18  comprising a lateral support configured to constrain lateral flexing of the elongate element. 
     
     
         23 . The disposable unit of  claim 22  wherein the lateral support comprises two opposing wall sections, and the elongate element sits between the sections in freely longitudinally, slidable engagement. 
     
     
         24 . The disposable unit of  claim 22  wherein the lateral support comprises two opposing roller elements arranged with a mutual clearance corresponding to a thickness of the elongate element, and the elongate element sits between the two opposing roller elements in freely longitudinally, slidable engagement. 
     
     
         25 . The disposable unit of  claim 18  wherein the elongate element is longitudinally outwardly constrained when the tissue device moves from the retracted position to the extended position. 
     
     
         26 . The disposable unit of  claim 18  comprising a physical electronic memory device. 
     
     
         27 . A biopsy device, comprising:
 a handle unit; and   a disposable unit releasably attached to the handle unit, the disposable unit including:
 a needle having a distal cutting edge; 
 a tissue device having a cavity, the tissue device movable between an extended position, in which the cavity projects from a needle distal end, and a retracted position, in which the cavity is proximal to the needle distal end; and 
 a transport device configured to move the tissue device between the extended position and the retracted position, wherein the transport device includes:
 an elongate element having a distal end attached to the tissue device, the elongate element having a toothed surface; 
 a rotatable gear engaged with the toothed surface; and 
 a coiling device configured to coil the elongate element as the tissue device moves from the extended position to the retracted position. 
 
   
     
     
         28 . The biopsy device of  claim 27  further comprising a control system for the transport device configured:
 to move the tissue device between the extended position and the retracted position; 
 and 
 to arrest the tissue device in the retracted position. 
 
     
     
         29 . The biopsy device of  claim 28  wherein the control system is configured to automatically detect a distance of the movement between the extended position and the retracted position. 
     
     
         30 . The biopsy device of  claim 28  wherein the control system is configured:
 to retract the tissue device toward the retracted position and to record as a proximal extremity position, P, a maximum retraction extent of the tissue device, 
 and 
 to use P as a reference point for a subsequent retraction. 
 
     
     
         31 . The biopsy device of  claim 30  wherein P and the retracted position are different. 
     
     
         32 . The biopsy device of  claim 28  wherein the tissue device has a pre-defined movement range extending to a proximal extremity position, P, and wherein the control system comprises a sensor configured to detect when the tissue device reaches P. 
     
     
         33 . The biopsy device of  claim 32  wherein P is defined by a mechanical stop, and wherein P and the retracted position are different. 
     
     
         34 . The biopsy device of  claim 28  wherein the handle unit comprises an electronic interface in signal communication between a physical electronic memory device and the control system to communicate information between the physical electronic memory device and the control system. 
     
     
         35 . The biopsy device of  claim 34  wherein the information represents a distance between the extended position and the retracted position. 
     
     
         36 . The biopsy device of  claim 28  comprising:
 a first firing mechanism configured to advance the needle and the tissue device; and 
 a second firing mechanism configured to move the needle from a first position, in which the tissue device projects from the needle distal end to a second position, in which the needle accommodates the tissue device cavity.