A disposable cannula base device for insertion within a guide tube in a hand-supportable power-assisted tissue aspiration instrument including a hand-supportable housing with a rear portion, a cannula reciprocation mechanism, and a stationary tubing connector with a hollow tube section mounted within the rear portion of the hand-supportable housing. The disposable cannula base device includes a permanent magnetic ring supported on a hollow tube portion, between a set of fluid seals. The cannula reciprocation mechanism reciprocates the disposable cannula base device within the guide tube by exerting electromagnetic forces on the permanent magnetic ring.
