Ground Contact Time Estimating Wearable Sensor to Measure Spatio-Temporal Aspects of Gait

Inpatient gait analysis is an essential part of rehabilitation for foot amputees and includes the ground contact time (GCT) difference of both legs as an essential component. Doctors communicate improvement advice to patients regarding their gait pattern based on a few steps taken at the doctor's visit. A wearable sensor system, called Suralis, consisting of an inertial measurement unit (IMU) and a pressure measuring sock, including algorithms calculating GCT, is presented. Two data acquisitions were conducted to implement and validate initial contact (IC) and toe-off (TO) event detection algorithms as the basis for the GCT difference determination for able-bodied and prosthesis wearers. The results of the algorithms show a median GCT error of -51.7 ms (IMU) and 14.7 ms (sensor sock) compared to the ground truth and thus represent a suitable possibility for wearable gait analysis. The wearable system presented, therefore, enables a continuous feedback system for patients and, above all, a remote diagnosis of spatio-temporal aspects of gait behaviour based on reliable data collected in everyday life.

Automated summary

Inpatient gait analysis is crucial for rehabilitation of foot amputees, and the ground contact time (GCT) difference between legs is an important factor. This study presents a wearable sensor system called Suralis, which utilizes algorithms to calculate GCT based on data collected from an inertial measurement unit (IMU) and a pressure measuring sock. The results show that the algorithms have a median GCT error of -51.7 ms (IMU) and 14.7 ms (sensor sock), making it a suitable option for wearable gait analysis. The system enables continuous feedback for patients and remote diagnosis of spatio-temporal aspects of gait behavior.