Kunihiko Oda

Development of isokinetic exercise machine using ER brake

ER fluid has rheological characteristics which can be controlled by the electric field. Using particle-type ER fluid, we developed a brake device. In this study, this ER brake was used in an isokinetic exercise system for rehabilitation training under restriction of constant rotational speed of a joint during exercise. Such a passive system using a brake is basically safe for human use.

Leg-Robot for Demonstration of Spastic Movements of Brain-Injured Patients with Compact Magnetorheological Fluid Clutch

In this study, we propose a leg-shaped robot (Leg-Robot) with a compact magnetorheological fluid clutch to demonstrate several kinds of haptic control of abnormal movements of brain-injured patients. This system can be used in the practical training for trainees of physical therapies (physiotherapists). In this paper, we especially focus on ankle clonus, which is one of the abnormal movements usually arising after stroke. We suggest a control method to demonstrate haptics of the ankle clonus. We also confirmed its effectiveness for learning of the test skill.

Leg-Robot with MR Clutch to Realize Virtual Spastic Movements:

In this study, we propose a leg-shaped robot (Leg-Robot) with a magnetorheological fluid clutch (MRFC) to demonstrate virtual haptic of spastic movements of brain-injured patients. The MRFC installed in this system makes it safer than conventional direct-driven robots. At the same time, the MRFC also improves quality of haptic to mimic the human-like reactions. This system is useful to learn diagnosis methods of physical therapy for its trainees. In this article, basic structure and mechanism of the Leg-Robot are explained. Then, control methods and experimental results of three types of spastic movements are described.

Development of leg-robot for simulation of spastic movement with Compact MR Fluid Clutch

In this study, we propose a leg-robot with a Compact MR Fluid Clutch (CMRFC) to realize haptic control of abnormal spastic movements of brain-injured patients. This system can be used in the practical training for trainees of physical therapy. Additionally, we will study to figure out the physiological mechanism of spastic movements of human with the process to simulate patient-like spastic motion by this robot. In this paper, basic structure and mechanism of the leg-robot with CMRFC are explained. Finally, experimental results of some kinds of haptic control for spastic movements are described.

Measurement of reaching movement with 6-DOF upper rehabilitation system “Robotherapist”

In recent years, the needs for rehabilitation support systems are increasing, which use robot technology and virtual reality technology. Applying these technologies make efficient rehabilitation possible. We have developed 6-degrees-of-freedom (DOF) upper rehabilitation support system to evaluate synergy pattern of stroke survivors and to train stroke survivors, named “Robotherapist”. When stroke survivors who can move plural joints only along a certain constant pattern called synergy pattern do reaching movement, some of them cannot keep their posture of the arm normal, but can move their hand along the aim orbit. In this study, we experiment on a measurement of reaching movement with our system and make a model of movement peculiar to stroke survivors and a model of movement of healthy people. Additionally, we propose application software for reaching training with this model. In this paper, we report measurement of reaching movement and propose application software for reaching training with our system.

A performance evaluation method of a passive type force display and rehabilitation system with redundant brakes

We developed a compact and low-cost quasi-3-DOF rehabilitation system “Hybrid-PLEMO” for upper limbs of stroke patients. Hybrid-PLEMO has 2-DOF force feedback function in working plane, its working plane can be adjusted the inclination, and it can be switched between active type and passive type. However, there are some directions and link positions which are difficult to display the force when Hybrid-PLEMO works at passive type. Redundant brakes method had been suggested to made it possible to display various force directions and various postures of virtual objects by the improvement of the controllability. In this paper, a novel method is presented for performance evaluation of a passive-type force display system with redundant brakes. Using this method, we evaluate the performance of a 2-DOF passive-type force display system with and without redundant brakes, and draw a conclusion that it is good to add redundant brakes to the passive-type force display and rehabilitation system.

Leg-robot with MR clutch to realize virtual spastic movements

In this study, we propose a leg-robot with an MR clutch to realize virtual haptic control for spastic movements of brain-injured patients. This system can be used in the practical training for trainees of physical therapy. Additionally, we will study to figure out the physiological mechanism of spastic movements of human with the process to simulate patientlike spastic motion by this robot. In this paper, basic structure and mechanism of the leg-robot with the MR clutch are explained. Finally, experimental results of some kinds of haptic control for spastic movements are described.

Preliminary experimental evaluation using a leg-shaped haptic simulator to quantify the diagnosing technique of ankle clonus

In this project, we have developed virtual haptic simulators that can simulate several kinds of abnormal movements and haptics of the disabled people. In the previous report, we proposed a leg-shaped robot (Leg-Robot) with a Compact MR Fluid Clutch (CMRFC) to establish highly safe human-machine co-existent system, and control methods to realize several kinds of abnormal symptoms. In this paper, we report experimental results in which young students of the physical therapy and an experienced physical therapist used the Leg-Robot. We were able to find obvious differences between them and this fact would verify that this system has a potential to quantify the diagnosing techniques for physical therapists.

Development of a 6-DOF Rehabilitation Robot and its Software for Clinical Evaluation Based on Virtual Reality

In recent years, the needs for rehabilitation support systems are increasing, basing on robot and virtual reality technology. We have developed a 6-DOF rehabilitation support system for upper limbs including wrists, named ROBOTHERAPIST. This system can measure positions and postures of an operators hand, and generate a feedback force for their upper limbs and wrists. Considered with the safety of the rehabilitation robot, ER (electrorheological) actuator has been designed by using ER fluid. This paper outlines the mechanical design and control system of ROBOTHERAPIST. And application software of physical therapy for clinical evaluation, based on proprioceptive neuromuscular facilitation (PNF) techniques, is also introduced in this paper.

Development of isokinetic exercise system using high performance MR fluid brake

Strengthening muscle force by training, e.g., an isokinetic exercise is widely used in rehabilitative activities or sports rehabilitations. However, many conventional isokinetic exercise machines cost expensive depending on its actuation device and safety system (hardware and software). In this study, we have developed highly safe isokinetic exercise systems using only brakes with functional fluids (ER fluid or MR fluid). Because of rapid response of these fluids, such a machine has good responsibility and controllability. In this paper, we describe basic concept and characteristics of Isokinetic Exercise system using MR fluid brake and its experimental results. In particular, high-speed (900deg/s at an elbow joint) control was realized with this system. Additionally, we suggest new training mode which we call iso-contractile exercise in this paper.