Ultrasonic probes for producing multiple cavitation volumes
Probes for delivering ultrasonic energy and related methods. The probe includes a shank having a shaft coupling a proximal end to a distal end. The shank is configured to propagate ultrasonic energy from the proximal end to a tip of the distal end in a propagation direction parallel to a longitudinal axis disposed along a centerline of the shank. The tip may be positioned to substantially coincide with a displacement antinode position when the ultrasonic energy corresponds to odd integer multiples of a quarter wavelength of a resonance frequency. Multiple grooves within the shaft are configured to create multiple cavitation volumes in a medium proximate to the shank responsive to the ultrasonic energy. The multiple grooves include a second groove intervening between a first groove and the proximal end. The first groove is positioned at a distance of an integer multiple of a half-wavelength of the resonance frequency.
1 . A probe comprising:
a shank including a proximal end, a distal end, and a shaft extending from the proximal end to the distal end, the proximal end of the shank configured to be coupled to a source of ultrasonic energy, and the shank being configured to propagate the ultrasonic energy from the proximal end to a tip at the distal end in a propagation direction parallel to a longitudinal axis of the shank;
a first groove within the shaft, the first groove positioned proximate to the tip; and
a second groove within the shaft, the second groove positioned along the shank between the first groove and the proximal end,
wherein the shaft includes a non-grooved section between the first groove and the second groove, the first groove is spaced from the second groove by a first distance approximately equal to a first integer multiple of a half-wavelength of a resonance frequency of the shank in the propagation direction, and the first groove is located proximate to a first location at which the ultrasonic energy corresponds to a first odd integer multiple of a quarter wavelength of the resonance frequency.
2 . The probe of claim 1 wherein the tip is positioned relative to the proximal end to substantially coincide with a first displacement antinode position when the ultrasonic energy corresponds to an odd integer multiple of a quarter wavelength of the resonance frequency of the shank.
3 . The probe of claim 2 wherein the proximal end is configured to be coupled to the source of ultrasonic energy at a point that substantially coincides with a second displacement node position when the ultrasonic energy corresponds to the odd integer multiple of the quarter wavelength of the resonance frequency of the shank.
4 . The probe of claim 1 wherein the second groove is located proximate to a second location at which the ultrasonic energy corresponds to a second odd integer multiple of a quarter wavelength of the resonance frequency.
5 . The probe of claim 1 wherein the first groove is included in a first plurality of grooves, and the second groove is included in a second plurality of grooves.
6 . The probe of claim 4 wherein the shank in the non-grooved section has an outer surface with a first diameter, and the shaft at a first position of each of the first plurality of grooves has a second diameter that is less than the first diameter.
7 . The probe of claim 6 wherein the shaft at a second position of each of the second plurality of grooves has a third diameter that is less than the first diameter, and the second diameter is equal to the third diameter.
8 . The probe of claim 5 wherein the shaft has an outer surface with a first diameter, the shaft includes a plurality of flanges that project from the outer surface, each of the first plurality of grooves is positioned between an adjacent pair of the plurality of flanges, and the shaft at a position of each of the first plurality of grooves has a second diameter that is equal to the first diameter.
9 . The probe of claim 1 wherein the shaft further includes a third groove intervening between the second groove and the proximal end, and the first groove is spaced from the third groove by a second distance approximately equal to a second integer multiple of a half-wavelength of the resonance frequency of the shank in the propagation direction.
10 . The probe of claim 1 wherein the shank includes a lumen extending from the distal end to the proximal end, and the tip includes a port coupled to the lumen.
11 . The probe of claim 10 wherein the lumen is configured to be coupled to an external source of suction.