Project Summary A significant number (~30-50%) of liver cancers have no curative treatments due to their proximity to critical anatomy. Minimally invasive thermal ablation is a promising treatment for these untreatable solid tumors. If delivered precisely, ablations offer the treatment efficacy of traditional surgery with lower patient risk, clinician time, and overall cost. Existing ablation technology, however, does not offer the necessary precision. Ablation tools do not provide feedback on (1) whether or not the probe has been accurately placed within the tumor, (2) if the tumor has been completely destroyed, or (3) if surrounding healthy tissue has been left intact. Because of this lack of precision and feedback, ablation cannot currently be used to treat tumors near critical anatomy. A proposed solution to these currently untreatable cancers is an ultraprecise ablation needle, embedded with high-resolution ultrasound sensors at its tip. These sensors will provide multiple benefits: aiding the clinician in placing the device correctly by imaging the tumor relative to the needle, delivering the treatment energy to a precise location through focusing, and providing real-time monitoring of the procedure by detecting the thermal changes in tissue-all without the need for a large imaging system. This innovation will allow surgeons to complete an ablation with the required precision to treat even the most difficult-to-reach cancers. This Phase 1 SBIR proposal will demonstrate the capabilities of small-scale ultrasound transducers to precisely control ablations near critical anatomical structures (e.g., arteries) in an in vivo porcine model through three specific aims: (1) optimization of previously developed ultrasound-based ablation zone estimation in ex vivo liver tissue using deep learning and physics-based simulations, (2) ablation zone estimation in an in vivo porcine liver model, and (3) demonstration of in vivo closed-loop ablation zone control near critical anatomy (artery in liver). Completion of this phase will demonstrate the key technology in a pilot animal study, where Phase 2 work would address critical development milestones to commercialization for an anticipated Class 2 device (approval via de nova regulatory pathway).