This paper describes the evolution of the Wheelchair Aerobic Fitness Trainer (WAFT), a wheelchair ergometer developed for determination of aerobic capacity and the diagnosis of coronary artery disease in lower limb disabled persons whose mobility depends primarily on the manual wheelchair. The device was originally developed for use in research studies to determine peak exercise capacity in persons with spinal cord injuries and other lower limb disabilities and to formulate associated graded exercise stress test protocols. In subsequent research, the device was incorporated into a specially designed testing station for the detection of coronary artery disease in persons who cannot adequately undergo treadmill or cycle ergometry testing because of lower limb disabilities. Based on the usefulness of the device for both rehabilitation and diagnostic purposes, the WAFT has been brought into the technology transfer process of the Department of Veterans Affairs Rehabilitation Research and Development Service. Under a contract with Packer Engineering, Inc., Naperville, IL, development of a preproduction version of the device and six units for field evaluation has commenced. The preproduction prototype of the WAFT has incorporated numerous improvements over the original device and promises to expand the potential for future research, rehabilitation, and diagnostic applications.