HELiOS® Personal Oxygen System for Nellcore-Puritan-Bennett®– The portable oxygen conserver is designed for the ambulatory patient in a home care environment. It is the smallest and lightest portable liquid oxygen system on the market that lasts up to 10 hours. The result was an ultra-compact package that initiated industry-wide growth in the use of liquid oxygen-based delivery devices. The award winning device is now marketed by Caire® Inc. under the names HELiOS Plus & Marathon®. We were hired to perform competitive benchmarking studies, and develop a product that incorporated their best features. Our technical input consisted of industrial design, mechanical engineering, human factors, ergonomics, and design for manufacture.