On the use of inertial measurement units for real-time quantification of pathological tremor amplitude and frequency

Quantification of pathological tremor amplitude and frequency is fundamental for clinical diagnosis of neurological disorders and for robotics based-tremor suppression. In this work, a novel approach for real-time estimation of tremor amplitude and frequency using inertial sensors is presented. First, a miniaturized MEMS sensor is attached to the patient's hand and calibrated with respect to it. This procedure permits to directly obtain wrist flexion/extension. Afterwards, a two stage algorithm for tremor estimation is implemented. It consists of a tracking algorithm that isolates tremorous movement, followed by an adaptive filter that estimates tremor parameters. The proposed technique has inherent zero phase, providing a tremor amplitude error of 0.3766 rad/s.