Breast biopsies have come a long way from the
open surgical procedures of decades ago. In today’s
procedures, technicians remove the tissue using a
several-mm-diameter cannula inserted in the breast.
While a significant improvement over the traditional
method, this approach can still require multiple
insertions of the cannula for optimal sampling, which
increases tissue trauma and recovery time. When
medical device manufacturer SenoRx decided to develop
an automated, handheld system capable of harvesting
multiple samples with a single insertion, they turned to
compact, accurate, high-torque motors from MICROMO.
In the SenoRx EnCor automated biopsy system, the
tip of the cannula is a solid, sharp tip; the sample is
harvested through a roughly 0.25 cm X 2 cm aperture
that opens up in the side. Vacuum pulls the tissue into
this opening. A cutter within the cannula slides up to
sever the tissue, which is drawn by vacuum into a tissue
chamber in the device. The cannula then rotates to
capture tissue at multiple other angular positions for
example, 0˚, 60˚, 120˚, etc.—without the need to remove
and reinsert the cannula.