-Remote Rehabilitation-
〜Establishment of remote control technology and Development of training systems〜

Research background

 In developed countries such as Japan, the low birthrate and the growing aging society, brings with it a lack of trained caregiver personnel. Because of this, visit to hospital become more difficult and the number of patients who cannot receive a satisfactory rehabilitation has been increasing. Also, there are also the cases when the elderly must take care of the patient.
 In this study, as an effective solution to this problem, we have proposed the remote rehabilitation provided to patients in at home to rehabilitation which has been done by the therapist at the hospital.
 Important matters by remote rehabilitation is considered as follows.
  • Patient safety is sufficient
  • It can recreate the rehabilitation made at the hospital
  • Quantitative evaluation of the patient's condition can be made through the robot
  • To provide appropriate training for patients

 In this study, we ensure the safety in order to achieve these goals. And, have this two as a feature.
  • Establishment of remote control technology that recreates accurately the patient's arm state
  • Development of training systems in order to provide training for patients

Remote control technology

 In this study, we study a system in which the therapist can provide rehabilitation to the patient at a distant place (at home) using remote control. The training object is range of motion exercise of upper limb.
 The training movement that the patient and the therapist perform together in the rehabilitation, is decided either by the recovery state or the physical condition of the patient. In this system, we recreate the joint hardness of the patient in the therapist side by using haptic feedback system so that the therapist can practice rehabilitation while getting this information through virtual reality.
 As a remote control technology, we make much of the sense of the therapist to a rehabilitation robot and adopt 2 degree of freedom master / slave systems in imitation of the structure of the arm and use Position-Force Bilateral Control for this system. However, under the influence of the delay of the communication system, the system may become unstable.
 In this system, we guaranteed stability for a communication delay problem by using an electromagnetic brake for the actuator of the master arm.

Training assistance system

 In this research, we are developing a method of efficient individual muscle training for patients or elderly people.
With this training system the patient is expected to train his muscle by himself. However, the motion in the training system is sometimes unclear. Therefore, we estimate muscle activities for specific weak muscles, and develop a motion for strengthen those weak muscles.
 A muscle activity level is expressed by the activity degree of the muscle. This can be measure by processing EMG(Surface Electromyography) signal. This muscle activity level is useful to check the state of the training and to analyze the output characteristic of FEM(Functional Effective Muscle)by using a musculoskeletal model for upper limb. We get a motion path to activate individual muscles and apply for muscle training by associating the muscle activities and its motion using biometric data and motion data.
 Hereafter, we are planning to improve the accuracy of muscle activity estimates, evaluate these estimated results and research about biofeedback for motion.
-Device to present weight-


Recently, there are more and more demands for human to work in extreme environments, such as outer space or disaster site. The use of skillful humanoid robot to replace human operator in such environments is desired. In that scenario, human operates the robot from a safe place afar by teleoperation control.
When a human operator operates a humanoid robot, it is very important that the human can feel the real sense of the situation. For example, if the operating method is too complex or the operator cannot have the sense of reality, the robot operation would become very difficult and not effective. Therefore, it is desirable that the robot operation system can present the sense of reality (e.g. sense of force or touch).

Device to present weight

 Our research group focuses on, among various sense information, the weight of the object being lifted. We have constructed a device that can present a sense of weight to the human operator. The device is constructed using three parallel wires, and uses three servo motors to generate tension on the wires. By adjusting the individual tensions, the device can inflict any arbitrary downward force, which is the total of the three wire tensions.

Bilateral telemanipulation between human and arm robot

 The position of a human's hand is measured by using a 3 dimension position measurement instrument (FASTRAK), and then sent to the robot side. Based on the information, a robot arm moves following the movement of the human's hand. When a robot hand, which is attached to the robot arm, grasps and lifts an object, the weight of the object is measured by a load cell and sent to the human side. At the human side, the weight presentation device reproduces the object's weight so that the human can feel the sense of weight, just like lifting the real object.

Research Theme



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