Duke University

Pei Zhong

Franklin H Cocks

Glenn M Preminger

Walter Neal Simmons

Georgy N Sankin

Haifan Lin

Nathan Smith

Yufeng Zhou

Franklin Hadley Cocks

Systems and methods for providing therapeutic shock waves are provided. A modified acoustic lens can include a first lens portion for directing a first part of an acoustic shock wave pulse toward a target and a second lens portion for directing a second part of the acoustic shock wave pulse toward the target. The second lens portion can be offset relative to the first portion such that transmission of the second part of the acoustic shock wave pulse through the second lens portion is delayed by a predetermined amount relative to transmission of the first part through the first lens portion. In situ superposition of the first and second pulses near and at the target can lead to the formation of a pressure waveform with idealized pulse profile and broadened focal width, which can provide for improved comminution of a concretion located within a living body with reduced tissue injury.

Acoustic lens for shock wave lithotripsy and related methods

Lithotripter apparatuses and methods are provided for selectively modifying an acoustic pressure field and can include a shock wave source operable to generate a shock wave having a substantially axisymmetric acoustic pressure field, an acoustic focusing member positioned between the shock wave source and a target, and an acoustic barrier positioned between the shock wave source and the acoustic focusing member. The acoustic barrier can be operable to selectively block a portion of the shock wave generated by the shock wave source such that the substantially axisymmetric pressure field is transformed into a modified acoustic pressure field.

Methods and apparatuses for generating a steerable pressure field in a shock wave lithotripter

A method to reduce vascular injury produced by lithotripter shock waves comprising the use of particular multi-pulsed shock waves which comminute human concretions with reduced vascular damage.

Method to reduce tissue injury in shock wave lithotripsy

This invention discloses an apparatus and method for producing microcavitational activity in aqueous fluids for non-invasive macromolecule delivery into living cells. A standard electrohydraulic shock wave lithotripter is fitted with an adjustable ring reflector that shares the same foci as the standard lithotripter hemi-ellipsoidal reflector. A small portion of the spherical shock wave, generated by the spark discharge at the first focus (F,), is reflected and diffracted by the ring reflector, resulting in a weak preceding shock wave approximately 8.5 &mgr;s in front of the lithotripter shock wave reflected and diffracted by the hemi-ellipsoidal reflector. The peak negative pressure of the preceding weak shock wave or pulse at F,can be adjusted from &minus;0.96 to &minus;1.91 MPa, using an output voltage of 25 kV. Living cells are exposed to the preceding shock wave and the lithotripter shock wave. With optimal pulse combination, the maximum efficiency of shock wave-induced cell membrane permeabilization can be enhanced substantially (up to 91%), by applying to the living cells a low dosage of, for example, 50 shocks. In addition, injury to mouse lymphoid cells is significantly increased at high dosage (up to 50% with shock number >100). The invention thus enables shock wave-inertial microbubble interaction to be used selectively to either enhance the efficiency of shock wave-mediated macromolecule delivery at low dosage or tissue destruction at high dosage.

Apparatus and method for macromolecule delivery into living cells

The invention discloses a microsecond tandem-pulse electrohydraulic shock wave generator for the comminution of concretions in vivo by controlled, concentrated cavitation energy. This apparatus generates a primary and a secondary shock wave pulse with a specified time delay in microseconds and pressure relationships, with the primary shock wave pulse being used to induce a transient cavitation bubble cluster near the target concretion, and the secondary shock wave pulse consisting of a sequence of reflected pulses producing a pulse that is substantially compressive to control and force the collapse of the cavitation bubble cluster towards the target concretion. This microsecond tandem-pulse is produced by the use of a plurality of ellipsoidal reflecting surfaces of the same focal length, but different major and minor axes. These two microsecond shock wave pulses, one having a compressive and a tensile component and one having essentially only a compressive component have been found to give concentrated energy deposition on the target concretion, while avoiding injury to surrounding tissue caused by random collapse of the cavitation bubbles, thus enhancing the efficiency of fragmentation of the concretion using shock waves while reducing potential deleterious injury to surrounding tissue.

Microsecond tandem-pulse electrohydraulic shock wave generator with

The invention relates to a method for the comminution of concretions in vivo by controlled, concentrated cavitation energy. This method utilizes two shock wave pulses with a specified time delay and pressure relationship, with the first shock wave pulse being used to induce a transient cavitation bubble cluster near the target concretion, and the second shock wave pulse to control and force the collapse of the cavitation bubble cluster towards the target concretion with concentrated energy deposition, while avoiding injury to surrounding tissue caused by random collapse of the cavitation bubbles. This invention makes it possible to significantly enhance the fragmentation efficiency of the concretion using shock waves while reducing potential deleterious injury to surrounding tissue.

Growing community of inventors

Chapel Hill, NC, United States of America

Pei Zhong