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Case A 65-year-old man with a completely transected left sciatic nerve at the buttock received an implant with a bioabsorbable nerve conduit over a 20-mm gap. The conduit was filled with collagen to facilitate nerve regeneration. At 4 years after implantation, reinnervation potentials were detected in the muscles, and there was sensory recovery in the reinnervated areas. Thereafter, motor and sensory function recovered gradually over a 14-year period. Conclusion Mixed nerve regeneration after conduit-based reconstruction was demonstrated objectively. Although it took >4 years for motor and sensory functions to be regained, the nerve connection between the buttock and the foot was restored.

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.

We have developed intelligently controllable ankle-foot orthoses (i-AFOs) that control their ankle motions with compact and high torque magnetorheological fluid brakes and those sensor systems. The i-AFO was applied to hemiplegic patients and a patient suffering from flaccid paralysis in his ankles. In the previous study, the i-AFO successfully identified the three different gait states, i.e. the initial contact, loading response, and swing phase, and also successfully achieved the avoidance of the abnormal drop foot in the swing phase. However, we did not accomplish the optimal control of the drop speed of foot in the initial contact (initial drop speed of foot, or IDSF in this paper). This report aims to investigate new control method of the i-AFO that focuses on the IDSF. The control model was developed on the basis of the experimental results of the healthy subjects, and the effect of the new controller was evaluated by a post-Guillain-Barre syndrome patient. The performance was evaluated with the kinematic information of the motion sensor installed in the i-AFO and estimated muscle activation simulated by inverse-dynamics software with mathematical models of human body. According to the results, the IDSF control at the initial contact successfully generated the virtual muscle activation of anterior tibial muscle and seemed to reduce the extra muscle activation of rectus femoris muscle.

We have developed an intelligently controllable ankle-foot orthosis (i-AFO). In this paper, we formulated a new control method for the i-AFO. In the method the sensor system of the i-AFO estimates walking speed of user and decide optimal drop speed of foot at the duration between initial contact and foot flat. We conducted the pretest for eight healthy subjects to make a control rule for the drop speed. Then we conducted the modeling test for one patient to make an estimation rule for walking speed. Finally we conducted the evaluation test for the proposed method. Despite the walking speed estimation show errors, the i-AFO successfully controlled the foot motion depending on the gait states.

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.

The present report details the successful development of a model for spinal cord injury (SCI). This model is simple, reproducible, and requires no laminectomy. Development of the model was carried out using fourteen dogs. A balloon catheter was inserted into the extradural space via the intervertebral foramen of each dog, then the balloon was inflated at the L1 level by injection of saline. Six dogs underwent compression with a balloon volume of 1.5 ml, three dogs with a volume of 1.0 ml, and the remaining five dogs were used as uninjured controls. We applied the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale to the dogs. Compression of the spinal cord for 10 min at 1.5 ml produced severe paraplegia (BBB remained zero or one for 6 months following surgery), while compression for the same time interval at 1.0 ml produced moderate paraplegia. Electrophysiological tests showed no hindlimb movement upon stimulation cranial to the site of injury in the 1.5-ml group. The volume of abnormal-intensity lesions in the 1.0-ml group calculated using MR imaging showed no marked changes in either high- or low-intensity lesions after 3 months, whereas in the 1.5-ml group, the low-intensity lesions alone showed a marked increase. Pathological examination of the damaged spinal cord showed the formation of cavities surrounded by scar tissue containing high levels of collagen. These findings closely resembled those of clinical cases. It was concluded that 10 min of balloon compression with a volume of 1.5 ml caused irreversible paraplegia in dogs.