Microprocessor-based weight shift monitors for paraplegic patients.

The prevention of pressure sores for patients with spinal cord injuries includes pressure relief through the patient shifting position and, thus, weight. We have designed a microprocessor-based device to mount on the seat of a conventional wheelchair. This device has applications in hospital rehabilitation programs for improving patient care and in research to study the cause and prevention of pressure sores. It can use audible alarms, which can be disarmed, to train patients to regularly shift weight. The device stores in its memory data on the interval between and the duration of weight shifts. The contents of this memory can be transmitted to a laboratory microcomputer system and displayed in tabular, graphical, or histogram formats. This device is more versatile than previous timer-based systems, not only because its timer and alarm parameters easily can be reprogrammed, but especially because it can store and play back detailed data on the patient's performance. The device is powered by rechargeable NiCad batteries, which can last several days without recharging.