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We have developed PLEMO-P3, a rehabilitation system for the upper limbs that utilizes ER brakes as torque generators and is a passive haptic device. To detect abnormalities in patients, we developed a new sensing device and installed it on the grip of the PLEMO-P3. In this paper, we compare several kinds of information from the sensor system (grasping force, reaction force against the working plane, and wrist joint range) and traditional stroke assessment (BRS, FMA and STEF). We establish effective assessment and training methods with PLEMO-P3, finding the effects of training and a strong correlation between them. We suggest a training method with PLEMO depending on the results of clinical assessment. We confirmed the correlation of the working plane reaction force and wrist joint range of motion and were able to detect synergy movement within the motion sensor wrist joint range. This correlation has been understood that it will equip it only with the wrist joint range of motion sensor in PLEMO-P4, a machine for practical use.1 1. This paper is the full translation from the transactions of JSME, Series C, Vol.76, No.762, pp. 323-330, 2010.

We have developed PLEMO to assist hemiplegic stroke patients in upper-limb rehabilitation using a passive haptic device with electrorheological (ER) fluid brakes. The PLEMO has no moving parts, ensuring safe rehabilitation assistance in the clinical setting. The previously reported version of the PLEMO can determine the operating force and the displacement of the grip by using conventional sensor devices; however, it was not enough to provide information evaluating stroke patient motor function. To cover such shortcomings of the conventional systems, we developed a new grip and motor-functional evaluation software that detects synergy, a symptomatic feature in stroke patients. In clinical evaluation of 14 stroke patients - two Brunnstrom Recovery Stage III, three Stage IV, and nine Stage V - we studied the correlation between PLEMO evaluation and rehabilitation evaluation, and found a strong correlation between them, e.g., changes in wrist movement range and table-reaction force provided useful information on stroke severity.

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.

Ankle-Foot Orthoses (AFOs) are orthotic devices supporting movements of ankles for disabled people for example hemiplegia, peroneal nerve palsy, etc. In our research, we have developed the intelligently controllable AFO (I-AFO) which can control its ankle torque by using compact Magneto-rheological fluid (MRF) brakes. In this paper, we describe the gait-control tests with I-AFO for a patient of the Guillain-Barre syndrome. The subject has difficulty in his voluntary movement of the peripheral part of the inferior limb, and there are physical limitations on his ankle. By applying the I-AFO, his gait control was improved by the prevention of drop-foot in the swing-phase and the forward promotion in the stance-phase.