Abstract

VILLA BEDOYA, Juliana  and  PETROFF, Neil. DEVELOPMENT OF AN ELECTRO-MECHANICALLY CONTROLLED HAND ORTHOSIS FOR ASSISTING FINGER EXTENSION IN STROKE SURVIVORS. Rev. ing. biomed. [online]. 2007, vol.1, n.2, pp.48-54. ISSN 1909-9762.

Stroke is the leading cause of long-term disability in the world. It causes chronic deficits, such as hemiparesis, especially prevalent in the distal upper extremities. An electro-mechanically driven hand orthosis has been developed to assess the potential therapeutic use of such devices in rehabilitating hand function. A small Direct Current (DC) brushed motor is used as the main actuator, and a cable-driven glove connected to the motor shaft is the central component of the device. The orthosis control is achieved through a force feedback loop using a miniature load cell attached in series to the cable and control module. The later, generates Pulse Width Modulated (PWM) and direction signals required to drive the motor. The speed is determined by the duty cycle of the PWM signal while the direction by the status of a flag bit modified by a user-operated switch. A portable design was achieved by using a 6 V battery pack as the power supply. The device is ready for use in clinical trials with stroke survivor subjects as it has already been tested on healthy individuals with satisfactory performance.

Keywords : DC motor; Force feedback control; Hand orthosis; Hemiparesis; Hemiplegia; Stroke.

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