Biopsy apparatus having integrated thumbwheel mechanism for manual rotation of biopsy cannula

A biopsy apparatus, comprising:

• a driver assembly having a housing configured to be grasped by a user;
• a disposable biopsy probe mechanism configured for releasable attachment to said driver assembly, said disposable biopsy probe mechanism being positioned at least partially within said housing when said disposable biopsy probe mechanism is attached to said driver assembly, said disposable biopsy probe mechanism including a biopsy cannula having a cylindrical side wall, a proximal end, a distal end and a longitudinal axis extending between said proximal end and said distal end, said cylindrical side wall defining a lumen and having a side port located near said distal end that extends through said side wall to said lumen;
• said driver assembly including a thumbwheel mechanism having a thumbwheel configured for rotation about a first rotational axis, wherein at least a portion of said thumbwheel is exposed external to said housing, said thumbwheel configured to be rotated to effect a manual rotation of said biopsy cannula to position said side port of said biopsy cannula at a desired rotational position about said longitudinal axis relative to said driver assembly;
• a detent wheel mounted to said biopsy cannula configured for coaxial rotation with said biopsy cannula about said longitudinal axis, said detent wheel having a circumferential surface and a plurality of detent recesses formed through said circumferential surface and extending radially toward said longitudinal axis, said plurality of detent recesses being positioned about said longitudinal axis at predetermined angular positions;
• and
• a lock mechanism mounted to said driver assembly, said lock mechanism including a locking pin biased along a locking axis in constant engagement with said detent wheel, said locking pin including an engagement end having a tapered portion and a non-tapered portion angularly offset from said tapered portion about said locking axis,
• configured such that when said locking pin is positioned in a first rotational position relative to said locking axis, said engagement end rides along said circumferential surface of said detent wheel and said tapered portion sequentially passes into and out of a respective detent recess of said plurality of detent recesses of said detent wheel as said biopsy cannula is rotated thereby providing at least one of aural, visual and tactile feedback of a progressive rotation of said biopsy cannula, and
• configured such that when said locking pin is positioned in a second rotational position relative to said locking axis, said engagement end rides along said circumferential surface of said detent wheel and said non-tapered portion lockably engages a next detent recess of said plurality of detent recesses of said detent wheel as said biopsy cannula is rotated to lock said biopsy cannula from further rotation.