Trends in powered upper limb prostheses ∗

As Prof. Tomovif: pointed out at the 3rd ETAN Symposium in 1969, realization of multifunctional mechanisms and development of multilevel control methods were the main subjects areas of interest in the field of powered upper limb prostheses in the latter half of the 1960's. In addition, the use of myoelectric potential as the source of control signals and utilization of electric stimulation for sensory feedback became a common method in the 5th ETAN Symposium i f 1975. The utilization of myoelectric potential as I the source of control signals was reported for the first time by Battye et al. in 1955 and the use of pulse electric stimulation as the feedback signal by Kato er a/. in 19701. While thees methods utilize a surface electrode, new attempts such as the direct insertion of an electrode into a nerve have been started. These will be described later. Recently, a manipulator for the disabled was developed with multiple .degrees of freedom. This can be placed on the working desk of an amputee requiring a prosthesis or placed on the table of a motorized wheelchair for patients with spinal cord injury requiring an orthosis. The patients can use the manipulator, which is driven by some signal, to accomplish their work.