Histotripsy Group
    Biomedical Engineering Department, University of Michigan

Research -> Acoustic Parameter Explorations

Acoustic Parameter Explorations


The relative contributions of thermal and cavitational effects in the therapeutic use of ultrasound are poorly understood. We systematically explored the acoustic parameter space within which tissue can be ablated by solely mechanical means (cavitation), without a significant thermal component.

For each parameter set (represented by the colored squares) the intensity is plotted against the time-average intensity on a logarithmic scale. The number within each square correspond to specific parameter sets. The observed porcine kidneytissue morpholologies (disrupted, mixed, blanched/desiccated, and no effect) achieved with various parameter sets clustered within distinct regions of the parameter sets clustered within distinct regions of the parameter space. Two-tone squares indicate parameter sets yielding two distinct morphologies. The dashed lines indicate values of duty cycle. A duty cycle of 100% corresponds to continuous application of energy.

References:
Kieran K, Hall TL, Parsons JE, Wolf JS, Fowlkes JB, Cain CA, Roberts WW, "Exploring the Acoustic Parameter Space in Ultrasound Therapy: Defining the Threshold for Cavitational Effects," 6th International Symposium on Therapeutic Ultrasound, S01 (2006).

Xu Z, Ludomirsky A, Eun LY, Hall TL, Tran BC, Fowlkes JB, Cain CA, "Controlled ultrasound tissue erosion," IEEE Trans. Ultrason. Ferroelectr. Freq. Control 51, 726-736 (2004).

Xu Z, Fowlkes JB, Ludomirsky A, Cain CA, "Investigation of intensity threshold for ultrasound tissue erosion," Ultrasound Med. Biol. 31, 1673-1682 (2005).

Xu Z, Fowlkes JB, Cain CA, "A new strategy to enhance cavitational tissue erosion by using a high intensity initiating sequence," IEEE Trans. Ultrason. Ferroelectr. Freq. Control 53, 1412-1424 (2006).