Wireless Accelerometer for the Detection of Falls Among Patients with Vertigo

摘要

In this paper we present a fall detection system using a triaxial accelerometer module for the prevention of falls and fall-related injuries among patients with vertigo. We recruited 26 healthy control subjects and 12 patients with vertigo for the study. The fall detection system used a triaxial accelerometer module (ADXL33; Analog Devices, Inc., Norwood, Massachusetts); signals were transmitted by a 2.4 G-Hz wireless link to a PC side receiver via a radiofrequency transmission module. Four accelerometer modules (attached to the forehead, waist, left thigh, or right thigh) were used to calculate the amount of acceleration change (AAC) during simulated falls and activities of daily living (sitting, standing, rolling on bed, and walking) among control subjects. We recorded Romberg, stepping, and tandem gait test data among participants in both study groups. For each activity of daily living and its reciprocal activity, there were no significant differences in AACs among most of the accelerometer modules (p > 0.05). Receiver operating characteristic curves showed that the waist sensor identified a true fall event with a sensitivity of 0.98 and that the forehead sensor identified a false fall event with a specificity of 0.97. Comparing Romberg test data between the study groups, there were significant differences in AACs among the forehead (3.38 vs. 1.74), left thigh (1.89 vs. 1.56), and right thigh (2.24 vs. 1.55) accelerometer recordings (p < 0.05 for all).