Initial clinical tests for assessment models of synergy movements of stroke patients using PLEMO system with sensor grip device

In recent years, many researchers have studied on the rehabilitation robotics to assist medical staff or patients. Some kinds of haptic devices have been developed and evaluated its efficiency with clinical tests, for example, upper limb training for patients with spasticity after stroke. Almost all the devices for upper limb rehabilitation have only 2-DOF for its active motion except for wrists. But the upper limb of human works in 3-D space even except for the wrist; therefore designing a rehabilitation system for 3-D training is important. To meet this demand, we have developed a rehabilitation system for upper limbs, “PLEMO”. PLEMO is a kind of haptic device. However, in the previous system, we could not detect symptoms of abnormal movement of patients, for example synergy patterns of stroke patients, because of a lack of sensors. In this paper, we developed new sensing device for detecting such abnormal symptoms. The purpose of this study is to build an appropriate evaluation system for stroke patients with such information of abnormal symptoms. As a first step, we conducted reaching/pulling tests with this device. In this clinical evaluation, the subject is six stroke patients with different Brunnstrom stages (3, 4, 5) and twenty seven healthy subjects. By comparison with a patient movement (stage 3, 4, 5) and a normal movement, we recognized some differences of gripping forces, grip rotation angle and ground reaction forces among their movements.