The goal of the rHEALTH sensor is to provide rapid, low-cost, handheld complete blood count (CBC), cell differential counts, electrolyte measurements, and other lab tests based on a reusable, flow-based microfluidic platform. For Phase II, we will develop an rHEALTH prototype to be delivered to NASA for reusable CBC, cell differential counts, and electrolyte measurements. Each subassembly and individual assay will be tested individually prior to full integration into the system level prototype. The rHEALTH sensor is a compact, portable device that employs cutting-edge fluorescence detection optics, innovative microfluidics, and unique capabilities. Based on its streamlined design, the rHEALTH sensor is able to perform a suite of different assays using a single drop of blood. Furthermore, the entire system allows cost-effective operation because of its nanoliter operating volumes. This is in contrast to existing point-of-care diagnostics devices such as the iSTAT and Piccolo systems which only perform one panel of assays per disposable reagent cartridge. The result is a highly practical, cost-effective, and powerful sensor. The successful completion of the Phase II program is a significant milestone for our rHEALTH sensor. It means that we would have been successful in shrinking hospital-sized clinical laboratory into a portable device.