Design and fabrication of a device for reducing hand tremor in parkinson patients during eating

In this paper, the method of designing a noninvasive device for eliminating hand tremors in Parkinson’s patients is presented. The designed device measures the tremors of the patient’s hand and implements the tremor control accordingly. Since Parkinson’s disease reduces patients’ abilities to perform daily activities, this device is designed as an electronic spoon. The inertial measurement units are used to measure hand tremors.

The signals got from motion sensors are passed through Butterworth’s second order low pass filters to attenuate signals amplitude at frequencies higher than the human hand’s natural frequency. The signals are sent to a proposed Proportional Integral (PI) fuzzy controller as a set point signal, and appropriate control signals are applied to two actuators installed orthogonal. Besides motion sensors, a microcontroller is installed inside the spoon handle that implements a PI fuzzy controller and provides control signals for two high speed servo motors installed perpendicularly.

As such, the spoon can minimize the tremor effect. In this system, no damper or mass is added to the hand, and the patients are not required to wear an orthosis. The contribution of this paper is twofold. First, we use sensor data fusion to increase measurement accuracy. In this paper, we use accelerometer and gyroscope sensors. Second, we proposed a robust PI fuzzy controller to compensate for the uncertainties and reduce the tremor.

The test results show that the hand tremor of Parkinson’s patients during eating is reduced up to 75% using this method.