Biomimetic Design of a Chest Carrying Nursing-Care Robot for Transfer Task

Patient transfer, such as lifting and moving a bedridden patient from a bed to a wheelchair or a pedestal pan and back, is one of the most physically challenging tasks in nursing care. We have developed a prototype nursing-care assistant robot that can conduct patient transfer by imitating the motion when a person holds another person on his/her back. Based on the measurement of human motions including back-chest touching, leaning forward, holding up, moving and putting down, we analyzed the key factors that may influence the safety and comfort of the patient and designed a new type of robot. The robot consists of a chest holder which moves like a human back. In this paper, we state the details of motion design and related kinematic/dynamic analysis of the robot and demonstrate its effect on patient transfer. It is demonstrated that the robot developed can transfer a subject from a bed to a chair and back.