Patent ID: 8012102

Claim:
A biopsy device, comprising: a biopsy cannula having a longitudinal axis, a lumen with a lumen wall, distal and proximal ends, and a sample chamber at the distal end of the biopsy cannula; an access opening located at a circumferential surface of the biopsy cannula providing access to the sample chamber, the access opening facing radially away from the longitudinal axis and the sample chamber having a blind end opposite the access opening formed by a portion of the lumen wall of the biopsy cannula to define a bottom of the sample chamber; a narrowing device positioned in the lumen of the biopsy cannula at a proximal end of the sample chamber to define a restriction in the lumen and an open area in the lumen, wherein a cross section of the open area between the narrowing device and the biopsy cannula at the restriction is less than 50 percent but greater than zero percent of a cross section of the lumen of the biopsy cannula, the open area being located to communicate with the sample chamber, the open area being positioned proximal to the access opening and at an opposite side of the lumen relative to the access opening at the blind end of the sample chamber; a retractable sheath disposed to be movable relative to the sample opening; and a vacuum source coupled in fluid communication with the lumen of the biopsy cannula for selectively supplying vacuum to the sample chamber via the open area at the restriction such that vacuum when applied will be brought to bear from the bottom of the sample chamber.