David P. Colvin

A Fall Intervention/mobility Aid System For Elderly And Rehabilitative Populations

A novel mobility-aid system called Fall-SafeTM has been developed to assist elderly and rehabilitative populations as well as to safely intervene and provide protection in the event of a fall. Its design is self-powered and is intended for use in nursing facilities, hospitals, and rehabilitation centers. An advanced, battery-powered version is also being developed for patient assistance and residential use. The Fall-SafeTM system is based on many years of research and development, which has included both analytical and experimental investigations into the accelerations and forces generated by human falls. This research has emphasized protection from fractures of the femur and hip due to falls, which are so common among the elderly. The system is also expected to promote independence by providing a safer means of ambulation and exercise, not only for the aged, but also for individuals recovering from surgery. The development of this new system has been sponsored by the National Institute on Aging under Phase I and I1 SBIR (Small Business Innovation Research) grants and has been used in pilot clinical trials under the direction of staff at Johns Hopkins.

Body Heat Stress Measurements With MacroPCM Cooling Apparel

Heat stress is a major problem for people who work or fight in hot environments while dressed in insulated or protective apparel. Such is the case for military personnel who must wear nuclear/biological/chemical (NBC) protective clothing or HAZMAT personnel as well as civilian personnel such as industrial workers, firemen, and costumed characters in amusement or theme parks. Responding to a request in 1991 by the NAVY to develop simple and lightweight cooling garments for use beneath NBC (nuclear/biological/chemical) protective clothing, the investigators at Triangle Research and Development Corporation (TRDC) have developed PECS (Personal Environmental Control System) and COOLTECH apparel, that utilizes 3–4mm diameter macro-encapsulated phase change materials or MacroPCMs to provide 1–2 hours of comfort and relief from heat stress, while permitting the garment’s thermal recharging without refrigeration or freezers.Copyright

Reduction in Body Vibration and Spinal Impact With HACS Cushioning

High vibration and impact injuries continue to cause problems for military and civilian personnel in aircraft, trucks and armored vehicles. Crashes in helicopters and fixed wing aircraft as well as repetitive impacts in armored vehicles and trucks over rough terrain can pose serious problems and potential injuries for their occupants. Protective seat cushions can be engineered to absorb or mitigate a significant fraction of the mechanical energy before it is transmitted to the body. It has been shown, however, that conventional foam seat cushions can actually increase the potential for injury by allowing the body accelerations to overshoot. On the other hand, new and novel designs for cushioning materials can significantly reduce the potential for injuries from whole body vibration as well as spinal impact by extending and altering the duration of the high energy mechanical pulse. Based on unique computer models and subsequent CAD/CAM designs, prototype HACS seat cushions were fabricated from elastomers of three different durometers that incorporated precision, lateral choked airflow passages molded into the cushioning material. Subsequent testing with the NAVY Crew System Horizontal Accelerator at Patuxent River Naval Air Station, MD showed that the novel HACS seat cushion was 40% more effective than any other conventional aircraft seat cushion for the reduction of lumbar spinal load transmission to crash test dummies of all sizes during 23g impact tests. In more recent testing for the AAAV armored vehicle program, HACS seat cushioning has been shown to reduce whole body vibration by 36%.Copyright

Development of a MacroPCM Neck Cooling Collar for Athletes and Runners

Investigators at Triangle Research and Development Corporation (TRDC) have developed materials and applications for enhanced thermal management using both micro-and macro-encapsulated phase change materials (PCMs) since 1983; including: microPCM coolants, coatings, composites, fibers and PCM apparel. The PECS™ (Personal Environmental Control System) was developed for microclimate body cooling beneath NBC (Nuclear-Biological-Chemical) protective clothing for the US NAVY and USMC (Colvin, 1997 and 2000). Similar cooling apparel using 3–4mm macroPCM COOLBEADS™ were developed for costumed characters at two theme parks as well as potential use by firemen (Colvin, 1998). The results for these programs were reported at the 2000 and 2002 ASME ICEME (Colvin, 2000 and 2002). Civilian apparel has included 3.5 lb and 5 lb vests, a 1.5 lb cowl as well as a 1-lb collar, which suggested the potential for the microclimate cooling of athletes. Extreme heat during outdoor sporting events can be a major problem for athletes. Competitive runners, who often generate 700–900 W/m2 , commonly deal with temperatures above 32.2°C (90°F) and a relative humidity greater than 80%. Natural cooling by evaporation and convection are often inadequate for a vigorously exercising athlete. Many athletes fatigue, drop out or have to wrap their chest and shoulders with ices and towels in order to finish the races. Ice and frozen gels, however, are uncomfortable, heavy, and can cause the blood vessels to constrict, thus restricting good blood circulation. Encapsulated PCMs can store 60 J/kg and the air spaces between the particles permit evaporation and convection as well as rapid thermal recharging. Development of an effective cooling collar could potentially permit competitive athletes to combat heat exhaustion and increase the body’s ability to dissipate heat.Copyright

Computer simulation of novel augmentative communications devices

Investigation into novel and useful communication aids for the deaf and nonverbal that are portable, cost-effective, and easy to operate has been hampered in the past by the lack of funding to develop prototype systems capable of satisfactorily testing new augmentative communication methodologies. A computer-based simulator was designed and clinically tested to allow the development and clinical trial of a wide selection of different portable communications devices. Suggested designs were then tested through repeated redesign cycles at minimal cost, allowing for the design and proving of multiple configurations and leading to an expedient series of final designs for actual prototype construction and field testing.<<ETX>>