Compact Wearable Ultrasonic Monitoring System for In-Suit Venous Gas Emboli Detection

Astronauts undertaking extravehicular activities (EVAs) are exposed to major physiological risks due to reduced pressure environment of spacesuits. One of the most critical risks is decompression sickness (DCS), caused by the formation of venous gas emboli (VGE) during transitions from pressurized habitats to low-pressure EVA suits. While existing pre-breathe protocols reduce DCS risk, they are resource-intensive, requiring substantial oxygen reserves and crew time. The increasing workloads associated with partial gravity EVAs further elevate the risk of DCS, prioritizing the need for innovative monitoring solutions. Current decompression bubble management is based on EVA simulations and defining pre-breath protocols prior moving to space. There is no technology to monitor DCS during EVA. Clearsens Inc. is a start-up company that aims to translate capacitive micromachined ultrasonic transducer (CMUT) technology for wearable ultrasound applications. The company simplifies the manufacturing process and enables highly efficient, wide-bandwidth, and small form-factor CMUT arrays. Our goal is to tailor the patented technology to this NASA need for enhancing astronaut safety, optimizing resource usage, and ensuring mission success. Our findings show that the technology is well suited to make a low-power, wearable ultrasound imaging system. The company proposes to adapt this technology for a wearable, non-invasive ultrasonic sensing system to enable real-time, in-suit detection of VGE. We propose to evaluate this novel technology as a wearable for decompression stress quantification (phase I) and, if successful, optimize its imaging scheme by doing human experiments for real-time processing (phase II). This system will provide critical physiological data, enabling astronauts to monitor their decompression status for a safer EVA operation. The system can be used in other DCS risk management required markets like aviation and diving.