In 1961, Norbert Wiener, the father of cybernetics, broke his hip and wound up in Massachusetts General Hospital. Wiener’s bad luck turned into fruitful conversations with his orthopedic surgeon, Melvin Glimcher. Those talks in turn led to a collaboration and an invention: the Boston Arm, an early myoelectric prosthesis. The device’s movements were controlled using electrical signals from an amputee’s residual bicep and tricep muscles.
What was the Boston Arm?
Wiener had first postulated that biological signals could be used to control a prosthesis in the early 1950s, but research in this area did not flourish in the United States.
Instead, it was Russian scientist Alexander Kobrinski who debuted the first clinically significant myoelectric prosthesis in 1960. Its use of transistors reduced the size, but the battery packs, worn in a belt around the waist, were heavy. A special report in the Canadian Medical Association Journal in 1964 deemed the prosthesis cosmetically acceptable and operationally satisfactory, with a few drawbacks: It was noisy; it only had two motions—the opening and closing of the hand; and it came in just one size—appropriate for an average adult male. Historically, most upper arm amputations resulted from combat injuries and workplace accidents, and so had disproportionately affected men. But the use of thalidomide during pregnancy in the early 1960s resulted in an increase of babies of both genders born missing limbs. There was a need for prosthetics of different sizes.
In 1961, Glimcher traveled to the Soviet Union to see a demo of the Russian Hand. At the time, he was working one day a week at the Liberty Mutual Rehabilitation Center, treating amputees. Glimcher and Thomas Delorme, the center’s medical director, noticed that many amputees were not using their prostheses due to the limitations of the devices. Liberty Mutual Insurance Co., which ran the rehab center, had a financial interest in developing better prostheses so that their users could get back to work and get off long-term disability. The company agreed to fund a working group to develop a myoelectric prosthetic arm.
Wiener suggested that Amar G. Bose, a professor of electrical engineering at MIT, and Robert W. Mann, a professor of mechanical engineering also at MIT, join the group. Bose and Mann in turn recruited grad students Ralph Alter, to work on signal processing and software, and Ronald Rothschild, to work on hardware. Over the next few years, this collaboration of MIT, Harvard Medical School, Massachusetts General Hospital, and Liberty Mutual developed the Boston Arm.
In 1966, MIT’s Research Laboratory of Electronics published Alter’s doctoral thesis, “Bioelectric Control of Prostheses,” as Technical Report 446. Alter had studied the electromyographic (EMG) signals stemming from muscle tissue and concluded they could be used to control the prosthesis. Meanwhile, Rothschild was working on his master’s thesis, “Design of an externally powered artificial elbow for electromyographic control.” Working with Alter, Rothschild designed, constructed, and demonstrated a motor-driven elbow controlled by emg signals.
Even as Rothschild and Alter were putting the final touches on their theses, Glimcher was teasing the press with the group’s experimental results during the summer of 1965. TheNew York Times ran a story claiming “New Process Will Help Amputee To Control Limb With Thought.” TheBosto
