Non-Invasive Bubble Detection in Tissue

Despite decades of research, numerous unanswered questions remain about the etiology of decompression sickness (DCS)—a serious risk for individuals exposed to large environmental pressure changes such as divers, rescued submariners, aviators, and astronauts. Several studies have suggested that micronuclei existing in tissue play a key role in the genesis and evolution of DCS. But to date, all the evidence is indirect, as no method for directly measuring or detecting tissue micronuclei currently exists. The size, shape, occurrence, and stabilizing mechanism of tissue micronuclei are not well characterized. The ability to directly measure tissue micronuclei could lead to revolutionary advances in the ability to predict, prevent, and treat DCS. During Phase I, we considered several candidate high-resolution imaging techniques to assess their ability to characterize micronuclei in laboratory phantoms and in animal tissue, ex-vivo and in-vivo. The results show that dual-frequency ultrasound provides the greatest sensitivity for detecting tissue bubbles. In Phase II, we will integrate a dual-frequency ultrasound instrument with a conventional ultrasound imaging machine to provide real-time micronuclei monitoring in an operational environment. We will validate the instrument with laboratory phantoms and animal tests. Finally, we will utilize the instrument to detect and characterize tissue bubbles in humans.