An Acoustic Device for Real-Time Monitoring for Decompression Sickness

Decompression sickness (DCS) can occur during rapid pressure changes such as when a diver ascends rapidly or during high altitude flights. Rapid decompression can causes gases dissolved in body fluids and tissues to come out of solution and form bubbles. The symptoms of DCS include painful joints, neurological dysfunction, dermal effects, and cardiopulmonary collapse. Currently, divers rely on decompression tables which specify the times that must be spent at specific depths before ascending to the surface. However the tables are based on statistical models, and there is no allowance to individualize preventive measures despite the fact that the appropriate decompression time can vary from person to person, and from dive to dive for an individual. This one-size-fits-all approach may put some divers at risk, or be overly restrictive to others. A diver wearable device that can monitor and measure the formation of gas bubbles in the body during decompression and provide near real time information on the numbers of bubbles and the sizes detected is thus needed for monitoring the health and safety of those undergoing decompression, for improving diagnosis of decompression sickness, and for developing novel mitigations for DCS prevention. In this project, the Dynaflow, Inc. and University of Maryland School of Medicine team will develop an acoustic device for the non-invasive detection and quantification of gas bubbles in tissue and biological fluids. We will apply new acoustic technology to detect formation of bubbles from 3 µm to 100 µm in diameter that are associated with DCS. The time required to collect data and analyze it will be a few seconds, thus allowing for near continuous monitoring. This device will be tested and validated using ex-vivo, and later in-vivo experiments. These studies will involve bubble detection ex vivo formation related to studies of human blood cells during decompression. The goal is to use this new technology to establish a direct association of small bubbles with blood-borne microparticles in decompression sickness pathophysiology.