An ultrasonically driven pump, which may be used for sampling body fluids or
atomizing
liquids, has a stationary outer needle and an inner needle mounted within the bore
of the outer needle. The distal end of the inner needle is positioned adjacent
to the distal end of the outer needle. The inner needle is ultrasonically vibrated
by an ultrasonic actuator without vibrating the outer needle, with resulting draw
of liquid through the distal end of the outer needle into the bore of the inner
needle for discharge through the proximal end of the inner needle. The outer needle
can be formed to have a penetrating tip suited for penetrating the skin of a subject
to allow sampling of body fluids including interstitial fluids. The pump can also
be used for atomizing liquid, by drawing liquid from a supply that is pumped from
the distal end to an open proximal end of the inner needle where the liquid is
discharged by atomization into the atmosphere.
