Tetuya Mouri

Development of a Hand Motion Assist Robot for Rehabilitation Therapy by Patient Self-Motion Control

This paper presents a new hand motion assist robot for rehabilitation therapy. The robot is an exoskeleton with 18 DOFs and a self-motion control, which allows the impaired hand of a patient to be driven by his or her healthy hand on the opposite side. To provide such potential that the impaired hand is able to recover its ability to the level of a functional hand, the hand motion assist robot is designed to support the flexion/extension and abduction/adduction motions of fingers and thumb independently as well as the opposability of the thumb. Moreover, it is designed to support a combination motion of the hand and the wrist. The design specifications and experimental results are shown.

Finger rehabilitation system using multi-fingered haptic interface robot controlled by surface electromyogram

In this paper, a new type of finger rehabilitation system with multi-fingered haptic interface controlled by surface electromyogram (sEMG) is proposed. We have developed the multi-fingered haptic interface robot: HIRO III, which can give 3-directional forces to 5 fingertips. This robot also can be use as compact rehabilitation device that can give the various fingertip exercises to fingertips of patient. And the sEMG helps to consider the patients intent. In this proposal system, first the fingertip motions will be extracted from sEMG of patient, afterwards the motions as a biofeedback will be provided to the patients fingertips with the compact device. So differing from completely passive rehabilitation, the proposed system can give patient the active rehabilitation that reflects patients intent. In this paper, the pretests with this system by ten able-bodied subjects are introduced. The purpose of this pretest is to confirm that fingertips are moved along users intention in the case of healthy body. The result shows that almost subjects feel the appropriate motion support from the device.

Sensibility control of redundant robots: sensibility directions along trajectory tangent vectors

This work is dedicated to accuracy control of redundant robot-manipulators using sensibility approach. A manifold structure is applied to realize bases transition at local robot level. This assures optimal choice of drive subsets or combination of drives realizing motion with desired sensibility. The formulated condition satisfaction in the robot configurational space leads to precise trajectory tracing in the working zone (coincidence of the sensibility direction with the trajectory tangent vector). An illustrative example is presented and the explicit results are shown. The group theory application completes the considerations and it is helpful for better mechanical interpretation

Sensibility Control of Redundant Robots: Force Compensation by Kernel Trajectories

This work is dedicated to force control of redundant robot-manipulators using the sensibility approach. It allows the robot to react to external force appearance without changing its kinematics state. The sensibility factor-group is introduced for description and analysis of the robot configuration space orthogonal fibrations. They divide the robot configuration space into four sets, each responsible for separate motion realization - one for position, one for orientation, one for both and one which does not affect the kinematics state. A concept of robot kernel trajectories is formulated and its application is clarified. The proposed approach is aimed to be applied for real time control of 7 d.o.f. robot. Simulations have been done for that robot taking into account its dynamics and sensibility models and applying the force control method. The results are presented further.

Development of a multifingered robotic human upper limb as an inverse haptic interface

Developing haptic interfaces has gained importance recently due to the wide range of applications they may cover, including those which were though impossible until recently. Although many interfaces were developed in the recent years, multifingered robotic human upper limb as an inverse haptic interface was never addressed. The paper presents a novel anthropomorphous upper limb as an inverse haptic interface, named Gifu Haptic Interface. The interface is similar to the human upper limb, from shoulder to fingertips, in shape, dimensions, and motion ability, is totally nonportable, is completely safe, and allows a wide range of applications as master or as slave, in actual and virtual environments.

HIRO: Multi-fingered Haptic Interface Robot and Its Medical Application Systems

This chapter presents the design and characteristics of a five-fingered haptic interface robot named HIRO and its medical application systems. The aim of the development of HIRO is to provide a high-precision three-directional force at the five human fingertips. HIRO consists of a 15-degrees-of-freedom (DOF) haptic hand, a 6-DOF interface arm, and a control system. The haptic interface can be used in a large workspace and can provide multipoint contact between the user and a virtual environment. Three medical application systems using HIRO, a hand rehabilitation support system, a medical training system using plural devices, and a breast palpation training system, are introduced. Furthermore, a hand haptic interface for an advanced palpation training system, which consists of a multi-fingered haptic interface for fingertips and 1-dimensional force display for finger pads, is presented. These systems show the great potential of HIRO.

Development of a Finger Pad Force Display for a Hand Haptic Interface

Most human interfaces in virtual environments use information of visual sensation and auditory sensation. By adding tactile sensation to these human interfaces, the human operator can handle objects with a realistic tactile sense and can perform complex tasks in the virtual reality environment. Haptic interfaces that present force and tactile feeling to the fingertips of a human operator have been investigated extensively over the last two decades [1]-[12]. Although some of these interfaces [9]-[12] provide three-dimensional force feeling to the human fingertip, few haptic interfaces cover the workspace of the human arm. These interfaces are classified into two types: wearable type interfaces [9], which are mounted firmly to the human hand, and opposed type interfaces [12], which are mounted in a position opposed to the human hand. These interfaces apply three-dimensional (3D) forces only to the human fingertips. Medical doctors must use palpation in examining patients, and the force and tactile sensation on both the fingertips and the finger pads are important in such palpation. However, training doctors to perform palpation is difficult, because this requires the cooperation of the patient. Thus a breast palpation training system in a virtual reality environment [13] would be useful as a training tool for palpation. However, due to the limitation of human finger length, developing a haptic interface that displays 3D force feeling to both the fingertips and the finger pads is not easy. The density of tactile sense organs in the human finger [14] is high in the fingertip and low in the finger pad. Hence, the human finger has a high sensitivity to 3D force at the fingertip but a low sensitivity at the finger pad. This suggests that a haptic interface that consists of 1D finger pad force display devices and a 3D fingertip force device would be effective for use in a virtual environment such as a virtual breast palpation training system. The present paper describes a hand haptic interface for use in a virtual training system in which not only fingertip force display but also finger pad force display is required. The hand haptic interface consists of novel finger pad force display devices and a 3D fingertip haptic interface, known as HIRO II [12], which was developed by our group. The developed finger pad force display device is driven by a flat-type brushless DC motor and is easy attachable to the finger pad. The applied force is controlled by a time interval control, which is an open-loop control. Here we present the design concept of the hand haptic interface, the control method and specifications of the finger pad force display device, and the results of an experimental evaluation of manipulating a virtual object. We also provide a comparative