HIFU Transducers Designs and Ultrasonic Treatment Methods for Biological Tissues

Abstract

The purpose of this study was to evaluate the feasibility of high intensity focused ultrasound (HIFU) for ultrasonic treatment of biological tissues, particularly, for hemostasis of deep arterial bleeding. The results of designing, modeling and evaluation of an ultrasound applicator capable of creating thermal lesions in the arterial vessels were presented. New effective HIFU transducers designs and ultrasonic methods for stopping deep arterial bleeding were developed and estimated. Mathematical modeling of the HIFU transducers and acoustic fields were performed. The experiments were made on acoustic vascular phantoms as well as on lamb’s femoral artery at a standard protocol. During ultrasound exposure, arterial blood flow was temporarily stopped using intravascular balloon. Postponed hemostasis was observed at lamb’s femoral artery experiments for all HIFU treatments. It was demonstrated that HIFU can be used to stop active bleeding from vascular injuries including punctures and lacerations. The results of theoretical modeling, acoustic measurements, and in vivo vascular experiments prove the efficacy, safety and selectivity of developed HIFU transducers and methods used for enhancing of tissue lysis and hemostasis.