Masahiro Takaiwa

Development of Active Support Splint driven by Pneumatic Soft Actuator (ASSIST)

In this study, in order to realize an assist of independent life for the elderly or people in need of care and relieve a physical burden for care worker, an active support splint driven by pneumatic soft actuator (ASSIST) has been developed. ASSIST consists of a plastic interface with the palm and arm and two rotary-type soft actuators put in both sides of appliance. In this paper, the fundamental characteristics of ASSIST is described, and then the effectiveness of this splint is experimentally discussed. Finally, the operation of ASSIST based on a human intention is described.

Development of Wrist Rehabilitation Equipment Using Pneumatic Parallel Manipulator

In this study, we aim at developing a mechanical device to support human rehabilitation motion of their wrist joint instead of a physiotherapist. Pneumatic parallel manipulator is introduced as a mechanical equipment from a view that pneumatic actuators bring minute force control property owing to the air compressibility and parallel manipulators feature of multiple degrees of freedom is suitable for the complex motion of human wrist joint. To cope with the shortage of physiotherapist, we propose a method to acquire P.T.s rehabilitation motion and implement it for a patient using the equipment. The validity of the proposed system is confirmed through some experiments.

Robust positioning control of pneumatic servo system with pressure control loop

The goal of this paper is to attain a robust positioning control of a pneumatic driving system. A positioning control system positively focusing on the pressure control is investigated from the view that the pressure control is indispensable for improvement of control performances. A disturbance observer is employed to improve the pressure response and compensate the influence of friction force and parameter change. Consequently the improvements of robustness against payload and of positioning accuracy have been attained.

Design of Wearable Power Assist Wear for Low Back Support Using Pneumatic Actuators

This research focuses on developing a safe, lightweight, power assist device that can be worn by people during lifting or static holding tasks to prevent them from experiencing low back pain (LBP). In consideration of their flexibility, light weight, and large force to weight ratio, two types of pneumatic actuators are employed in assisting low back movement for their safety and comfort. At first, McKibben-type pneumatic rubber artificial muscles were chosen as actuator A to provide the assistance force, and subsequently it is improved by using elongation type pneumatic rubber artificial muscles as actuator A. Actuator A is installed in the outer layer of the garment, and its two ends are fixed on the shoulders and thighs. It can output contractile force, assisting the erector spinae muscles in the same direction. Compared to McKibben-type pneumatic rubber artificial muscle, the elongation type has a larger contraction rate. Actuator B is a layer-type of pneumatic actuator; it is composed of two balloons, and it is installed in the inner layer of the garment. The biomechanical model of the human spine is analyzed, and get to know the main reason of LBP: when the human is bending forward and lifting a load, for the erector spinae muscles have a small lever arm, the spine has to bear a large amount of force, which is several times of body weight. By taking into account the biomechanic structure of the human spine, this device can provide support in two ways. Actuator A acts as an external muscle power generators to reduce the force requirement for the erector spinae muscles. As actuator B acts as a moment arm of the contractile force generated by actuator A, it will increase the effective amount of torque. The device can be worn directly on the body like normal clothing. Because there is no rigid exoskeleton frame structure, it is lightweight and user friendly. The systems Inertial Measurement Unit (IMU), composed of accelerometer sensors and gyro sensors to measure the human motion signals, can monitor the angles of the human body in real-time mode. By measuring the EMG signal of the human erector spinae muscles, the assistance effectiveness of the proposed device has been proven through experiments.

Power Assist Wear Driven with Pneumatic Rubber Artificial Muscles

In the coming advanced age society, an innovative technology to assist the activities of daily living of elderly and disabled people and the heavy work in nursing is desired. To develop such a technology, an actuator safe and friendly for human is required. It should be small, lightweight and has to provide a proper softness. A pneumatic rubber artificial muscle is available as such actuators. We have developed some types of pneumatic rubber artificial muscles and applied them to wearable power assist devices. A wearable power assist device is equipped to the human body to assist the muscular force, which supports activities of daily living, rehabilitation, heavy working, training and so on. In this paper, some types of pneumatic rubber artificial muscles developed in our laboratory are introduced. Further, two kinds of wearable power assist devices driven with the rubber artificial muscles are described. Some evaluations can clarify the effectiveness of pneumatic rubber artificial muscle for such an innovative human assist technology.

Development of force displaying device using pneumatic parallel manipulator and application to palpation motion

The goal of this study is to develop a mechanical system which display elastic characteristic like stiffness on the surface of human body aiming at applying to palpation simulator. Pneumatic parallel manipulator is employed as a driving mechanism, consequently, it brings capability of minute force displaying property owing to the air compressibility. Compliance control system without using force/moment sensor is constructed by introducing a disturbance observer and a compliance display scheme is proposed. The validity of the proposed scheme is verified experimentally.

Development of pneumatic lower limb power assist wear driven with wearable air supply system

Many kinds of power assist device have been developed, and are driven with various actuators such as an electric motor, a hydraulic cylinder and so on. By using the exoskeleton, a high generated torque actuator can be introduced. An assist performance of these devices becomes high. On the other hand, a realization of exoskeleton which has the same D.O.F of a human is not easy from considerations about a size and strength of device. In this study, the power assist wear for lower limb is developed. The developed wear is like trousers. A human can be assisted by just wearing trousers on which the pneumatic soft actuators are put. The pneumatic soft actuator has a high power weight ratio, and has a light weight. These features contribute to realize the simple structure which is like clothes. In this paper, the structure of power assist wear is discussed, and the application of power assist wear to assist going up and down stairs are described.

Wearable Master-Slave Training Device for Lower Limb Constructed with Pneumatic Rubber Artificial Muscles

The purpose of this study is to develop a wearable master-slave lower limb training device for a trainer and a trainee. The developed device is constructed with McKibben type rubber artiacial muscles and an appliance, a torque sensor. In addition, to prevent applying an excessive torque to the trainee, a reaction torque from the trainee can be transmitted to the trainer by a bilateral type master-slave control system. In this paper, the structure of the developed device is discussed, and then the validity of the proposed device is evaluated from the experiments assumed a training.

Application of artificial pneumatic rubber muscles to a human friendly robot

When robots work together with a human or contact with a human body directly in such as a medical welfare field, in order to avoid an accident from crash and so on, a flexibility is required for the robot. The purpose of this study is to realize a safe mechanism for a human-friendly robot. In this paper, the structure and the fundamental characteristics of a pneumatic rubber muscle and soft mechanism are described, and then the structure and the fundamental operation of the developed soft hand are shown. Finally, the shaking hands is discussed as an example of force communication tasks between a robot and a human.

Development of wrist rehabilitation equipment using pneumatic parallel manipulator -Acquisition of P.T.'s motion and its execution for patient-

In this study, we aim at developing a mechanical device to support human rehabilitation motion of their wrist joint instead of a physiotherapist. Pneumatic parallel manipulator is introduced as a mechanical equipment from a view that pneumatic actuators bring minute force control property owing to the air compressibility and parallel manipulators feature of multiple degrees of freedom is suitable for the complex motion of human wrist joint. To cope with the shortage of physiotherapist, we propose a method to acquire P.T.s rehabilitation motion and implement it for a patient using the equipment. The validity of the proposed system is confirmed through some experiments.