Experimental Evaluation of Training Device for Upper Extremities Sensory-Motor Ability Augmentation

The aim of our research was to develop and evaluate FES system for augmenting the sensory-motor abilities of the hand. The system is designed to train the finger flexors and finger extensors by accomplishing the force tracking task in isometric conditions. The system is designed to allow full voluntary control of hand opening or closing, while the FES is added for facilitating the voluntary contributions of the patient. The FES is closed-loop controlled according to the difference between the desired and actual force. Actual forces are acquired by a specially designed adjustable measurement device instrumented by two force sensors. The visual feedback about tracking performance is provided to the patient. The system was evaluated in experimental training study with two incomplete tetraplegic patients. In addition to the therapeutic treatment, the patients trained with the FES system approximately 45 minutes per day over a period of 4 weeks. After the training period, the results show that both patients have strengthen the finger flexor and extensor muscles and reduced the tracking error. Results thus imply to the improvement of grip force control.