US Patent 8690793 Biopsy device having rotational cutting

A biopsy device includes a probe assembly and a driver unit. The probe assembly includes a first cannula having a first aperture extending to a lumen proximal to a first distal end of the first cannula. A second cannula has a second aperture extending to a lumen proximal to the second distal end of the second cannula. The second cannula is disposed co-axially with the first cannula. A least one of the first aperture and the second aperture has a cutting edge. The driver unit is configured for releasably mounting the probe assembly. The driver unit is operatively configured to simultaneously rotate the first cannula and the second cannula at different rotational velocities so that the first aperture and the second aperture periodically come into alignment to form a virtual tissue sample aperture.