Project Abstract/Summary Mechanical properties of tissues are important biometrics for disease diagnosis and management. Yet, accessing such data with high accuracy levels during ambulatory activities is not well investigated. Elastography or tomography methods are standard-of-care technologies for detecting tissue mechanics with high resolution, but the complex and bulky setup poses a big challenge for precise measurements on moving subjects. Existing portable or wearable technologies need professional calibration at target locations as well as needing a confined, static testing condition. The accuracy drops when the subjects move, making the assessment especially challenging in long-term, in-home settings. Here, we propose to develop a wireless, wearable elastography device for ambulatory monitoring of tissue mechanics. We will invent a real-time, calibration-free elastography method based on the measurement of pulsed surface waves from an array of skin-mounted accelerometers. We will build an optimized, broadband actuation-sensing mechanism on a wireless, soft electronics platform, which can be securely mounted to the body surface at various anatomical locations. The heterogeneous hard-soft materials integration strategy will enable wearable electronics for excitation and detection of elastic waves propagating at the skin-air interface. An automated algorithm, based on spectral wave analysis, is calibration- free and insensitive to variance in signal amplitudes originating from, for example, motion artifacts. The untethered, soft-patch electronics that can tightly conform to the body surface, together with the motion- insensitive algorithm, will allow for ambulatory monitoring of tissue mechanics immune to intensive physical activities. We will thoroughly test the wearable elastography device accompanied by a cloud-based analysis platform for high-throughput detection of mechanical parameters on tissue-mimicking phantoms and moving subjects. We will validate the performance of the device against the ground-truth measurement from dynamic mechanical analysis or ultrasound elastography. The accumulated preliminary data from this project will pave the way for further work leading to clinical translations of this technology.

Project Narrative Mechanical assessment of soft biological tissues has broad relevance in clinical diagnosis, but there yet exists any technology that can measure tissue mechanics during normal activities. The proposed wireless, wearable elastography technology will allow ambulatory monitoring of tissue mechanics on human subjects at a wide range of anatomical locations of interests. This unconventional monitoring capability outside the clinic can uncover new mechanical biomarkers with implications for diagnosis and management of a range of diseases/conditions.