Patent ID: 9669203
Date: 2017-06-06
CPC Classifications: A61B,A61M

Claim:
1. A method for inducing and passively detecting stable cavitation for targeted drug delivery across a biological membrane, comprising: administering vesicles comprising a nucleating agent and a therapeutic drug to a target vascular system of a patient; providing intermittent active intervals of ultrasonic exposure substantially throughout a targeted treatment zone within the vascular system of the patient, said active intervals each lasting an active interval duration and being separated by rest periods, each rest period lasting a rest period duration during which no ultrasonic energy is provided, wherein the ultrasonic exposure is produced by a source transducer at a specified fundamental frequency, amplitude, duty cycle, and duration; detecting a scattered ultrasonic wave, wherein the scattered ultrasonic wave is received by a detection transducer and the scattered ultrasonic wave comprises a derivative frequency of the fundamental ultrasonic frequency comprising at least one of a subharmonic frequency and an ultraharmonic frequency, wherein detection of the derivative frequency is indicative of stable cavitation; and modifying the active interval duration and rest period duration to maintain stable cavitation by leaving the source transducer on when scattered ultrasonic waves of the derivative frequency are detected, and initiating a rest period when scattered ultrasonic waves of the derivative frequency decrease or are not detected.