Design of a Novel Telerehabilitation System with a Force-Sensing Mechanism

• Main Authors: Songyuan Zhang, Shuxiang Guo, Baofeng Gao, Hideyuki Hirata, Hidenori Ishihara
• Format: Article
• Language: English
• Published: MDPI AG 2015-05-01
• Series: Sensors
• Subjects: telerehabilitation system; closed-loop interaction control strategy; series elastic actuator; force-sensing mechanism; inertia sensor; contact-less angle sensor; force sensor
• Online Access: http://www.mdpi.com/1424-8220/15/5/11511

Many stroke patients are expected to rehabilitate at home, which limits their access to proper rehabilitation equipment, treatment, or assessment by therapists. We have developed a novel telerehabilitation system that incorporates a human-upper-limb-like device and an exoskeleton device. The system is designed to provide the feeling of real therapist–patient contact via telerehabilitation. We applied the principle of a series elastic actuator to both the master and slave devices. On the master side, the therapist can operate the device in a rehabilitation center. When performing passive training, the master device can detect the therapist’s motion while controlling the deflection of elastic elements to near-zero, and the patient can receive the motion via the exoskeleton device. When performing active training, the design of the force-sensing mechanism in the master device can detect the assisting force added by the therapist. The force-sensing mechanism also allows force detection with an angle sensor. Patients’ safety is guaranteed by monitoring the motor’s current from the exoskeleton device. To compensate for any possible time delay or data loss, a torque-limiter mechanism was also designed in the exoskeleton device for patients’ safety. Finally, we successfully performed a system performance test for passive training with transmission control protocol/internet protocol communication.