Many people of all ages have sustained cervical cord injury in traffic accidents or sport accidents, and con sequently suffered physical impairment. For individuals with paralysis of the lower limb who have also lost the ability to extend the elbow, many motions become difficult to perform in daily life, for example, independently operating a wheelchair or pushing open doors. In the future, wearable assist robots are expected to be incorporated into daily life. In order to be wearable, the assist robot must not limit the user's range of motion while being carried or used, and must be suitable for a wide range of situations. In this study, we developed an assist robot for upper limb movement which can assist wheelchair operation. To achieve this, we constructed a model of the upper limb during wheelchair operation with a manipulating force ellipsoid, and we developed an assistance control method for the upper limb using the device to apply force vectors. The effectiveness of the developed system is demonstrated experimentally.

Many people of all ages have sustained cervical cord injury in traffic accidents, falls, or sport accidents, which has resulted in their physical impairment. Among such individuals, dysfunction of the upper limb is of particular concern, even though recovery from dysfunction is possible through rehabilitation. In this study, we developed a wearable assistive robot for the upper limb; this robot can be used to perform various tasks involving upper limb motion in daily life. To achieve this, we devised an algorithm for assisting extension motion. Individuals with C5-level Cervical Cord Injury (CCI) cannot perform extension of the elbow on their own. Therefore, we calculated the reference velocity curve and the angle of extension only from the force in the direction of flexion. In this way, the wearer can autonomously adjust the movement.