PROJECT SUMMARY Safe and reliable access to major blood vessels and internal organs will be beneficial to patients with cardiovascular and cardiothoracic diseases. An interventional catheter with forward-viewing ultrasound imaging capability will be developed to enable image-guided access to blood vessels and internal organs. Phase 1 and 2 experiments demonstrate feasibility of building a high resolution, forward-viewing ultrasound array and its ability to yield clinical quality images of ex-vivo and in-vivo tissues. This Phase 2B SBIR proposal seeks to build on the Phase 2 results and develop a clinical production grade device. Furthermore, we will demonstrate feasibility and safety of the device in its exemplary clinical uses in preclinical testing and in human studies. The production grade device will meet regulatory and clinical requirements and image quality to produce accurate and safe device guidance to target organs, particularly large blood vessels and the heart. We therefore propose to: a) demonstrate acceptable image quality and biological safety using the go-to-market device, b) demonstrate safety, functionality, and efficacy in vivo using the go-to-market device and, c) establish clinical feasibility and safety profile of the go-to-market device in a human study for its exemplary uses (femoral arterial access, pleural and pericardial access). No such device is currently available in the market and the successful development of a clinically implementable device has immense commercial potential by its ability to contribute significantly to the advancement and expansion of minimally invasive medical procedures.