Monitoring rehabilitation training for hemiplegic patients by using a tri-axial accelerometer

In rehabilitation training for hemiplegic patients, bed-to-wheelchair transfer is most important and allows a patient´s early independence. We developed a monitoring system for transfer training that is quantitative and uses accelerometry. Two tri-axial accelerometers were attached to the subjects, at the head and waist. Subjects were trained in moving from a sitting position to standing, then turning through, about 90 degrees, and then sitting on the bed. The acceleration signals at the two sites were recorded via a multi-telemeter system, converted to a digital signal, and stored in a computer. Data were analysed by LabView and displayed on the computer screen as real time motion. The system can be operated by one staff member, and the patients did not feel restricted. We were able to evaluate the time course of the signals, and phase-plane locus of the vertical, lateral and horizontal directions of the signals. The transfer of hemiplegic patients occurred in two motions: a standing-up motion, and a sitting-down motion. Accordingly, we observed twin peaks in the plot of the original signal. In contrast, healthy volunteers moved smoothly and twin peaks were not present.