Acoustic-anatomic modeling and development of a patient-specific wearable therapeutic ultrasound device for peripheral arterial disease - PROJECT SUMMARY Peripheral arterial disease (PAD) is a highly prevalent condition that is growing rapidly due to shifting demographics, affecting 202M people worldwide and 18M in the USA, with an annual growth rate of 6.8%. Early stages of PAD result in claudication, while the advanced stage of PAD results in resting pain, skin ulcers, gangrene and amputation, all of which reduce mobility, function and independence of seniors. Advances in catheter-based therapies including angioplasty, stenting, and drug-coated balloons, as well as surgical bypass treatments, are often ineffective in PAD and associated with complications and up to 40% rate of long-term restenosis. Acoustic energy modalities such as therapeutic ultrasound (TUS) have been shown to promote collateral vessel growth, angiogenesis, and to improve perfusion in animal models of coronary artery disease and PAD, with promising early human data in both disease processes. Vibrato Medical has developed a novel treatment with the first wearable therapeutic ultrasound (TUS) device for the non-invasive, outpatient treatment of PAD that will promote collateral vessel growth and angiogenesis, restore perfusion and reduce amputation rates. We have already demonstrated VibratoSleeve’s efficacy in markedly improving lower extremity perfusion in healthy volunteers using multiple perfusion measures with as little as 30 minutes of therapy over the posterior calf. However, this was done with a device of a single size/frequency regardless of patient size, and patients at the extremes of size may not have optimal safety and efficacy. The goal of this Phase 1 SBIR proposal is to systematically measure depths of subcutaneous fat, gastrocnemius/soleus muscle, posterior tibial artery and bone from the VibratoSleeve’s posterior calf approach, and over a wide range of patient sizes. These anatomic measurements will be used to inform acoustic simulations, that will then predict the size and frequency of transducers needed to provide safe and effective therapy to the posterior tibial angiosome. Candidate transducers will be assembled based on simulation data, and incorporated into 16-transducer VibratoSleeve arrays in a commercially viable manner.