Simple Microcontroller-Based Walking Speed Measuring Device

Walking speed provides a useful indicator of individual health. Walking speed measurement is usually conducted manually using a stopwatch. In this paper, we develop a microcontroller-based automatic walking speed measuring device (WSMD) which incorporates two infrared photo-detectors. Time measurement accuracy of the proposed device was kept within ± 1 ms by employing a dedicated counter circuit. In this study, 48 data points of walking speed from four subjects (with three repeated measurements from each subject) have been obtained using the proposed WSMD device, stopwatches operated by two observers, and Perception Neuron Accelerometer Suit (PNAS) device. The proposed WSMD shows higher linearity and precision and lower measurement bias over repeated measurement compared to manual measurement using stopwatches. Additionally, the proposed device shows a good correlation with the PNAS device indicated by an R-square value of 0.967 and p-value of 0.981.