Noninvasive acoustic manipulation of objects in a living pigs using a phased array: These beams were shown to levitate & steer solid objects (3-mm-diameter glass spheres) along preprogrammed paths

Noninvasive acoustic manipulation of objects in a living body. Mohamed A. Ghanem, Adam D. Maxwell, Yak-Nam Wang, Bryan W. Cunitz, Vera A. Khokhlova, Oleg A. Sapozhnikov, and  View ORCID ProfileMichael R. Bailey. Proceedings of the National Academy of Sciences, July 6, 2020. https://doi.org/10.1073/pnas.2001779117

Significance: The significance of this work is the development of a technique and technology to use a steerable beam from one source to safely lift and reposition a stone in a living body. The work has direct application to expelling kidney stones or manipulating an ingestible camera. Our work provides a framework for other medical applications, as well as nonmedical uses that require noninvasively moving sizable, dense objects in a free field or within a container.

Abstract: In certain medical applications, transmitting an ultrasound beam through the skin to manipulate a solid object within the human body would be beneficial. Such applications include, for example, controlling an ingestible camera or expelling a kidney stone. In this paper, ultrasound beams of specific shapes were designed by numerical modeling and produced using a phased array. These beams were shown to levitate and electronically steer solid objects (3-mm-diameter glass spheres), along preprogrammed paths, in a water bath, and in the urinary bladders of live pigs. Deviation from the intended path was on average <10%. No injury was found on the bladder wall or intervening tissue.

Keywords: acoustic tweezersacoustic radiation forcekidney stones