An ambulatory fall monitor for the elderly

Prevention of falling during walking or transfer is important for maintaining quality of life in the elderly. Analysis of falls among the elderly is useful not only for preventing falls, but also for detecting disease in its early stage. The aim of this study is to develop an ambulatory monitor that records falling time. The system consists of a fall sensor, a sensor driver circuit, a microprocessor and a real-time clock. A photo-interrupter is used as the fall sensor because it does not require an electrical switch. The photo-interrupter outputs a trigger signal when the subject is falling and the microprocessor records the falling time. To minimize the power consumption, the photo-interrupter is driven with pulse current, and the microprocessor that records falling time is only operated when the subject is falling. The system works continuously for one week. In this preliminary study, the system was tested for normal adults and hemiplegic patients, and operated without any trouble. Using this ambulatory system, we can obtain data about falling over a long period.