Inventors Who Improved Assistive Technology

Braille built a system that could be read by touch and written with a slate and stylus. Its six-dot cell could carry letters or music, and his 1829 publication described both. That shared cell explains why the system was more than a way to label things: readers and writers could work with a whole text.

A reliable braille writer needs the same dot height whether its keys are struck firmly or lightly. Abraham worked on the machine that Perkins introduced in 1951, giving it a key action that made uniform dots and a light enough touch for young children. It's a case where improving the feel of a tool changed who could use it.

Nemeth developed a braille code that could express the notation he needed for advanced mathematics. Writing an equation depends on being able to tell an exponent from a coefficient or follow where a fraction ends. His work gave blind math students a way to read and write that structure themselves.

Klein's team at Canada's National Research Council tackled electric wheelchairs as a steering problem as well as a power problem. Independent wheel drives and a joystick-style controller meant the user could direct the chair from their seat. The 1953 design report makes a useful starting point for seeing what changed mechanically.

Weitbrecht's acoustic coupler made a teletypewriter usable over an ordinary telephone connection. Deaf callers could exchange typed messages, and collaborators James Marsters and Andrew Saks helped spread the approach. The device solved a practical problem of access to the existing phone network.

When movies converted to sound, Romero experimented with giving Deaf viewers the dialogue back. He spliced caption frames into films. The technique interrupted the picture, but it made the missing text visible, and it shows what early captioners had to solve separately from the filmmaking itself.

McNaughton led the Toronto team that started using Blissymbols with nonspeaking children with physical disabilities in 1971. The team worked with a system originally invented by Charles Bliss, then learned from the children using it to communicate. Its simple shapes could stand for both objects and ideas.

Ingeborg and Erwin Hochmair developed a multichannel cochlear implant at the Technical University of Vienna, and work with the university clinic led to implantation in 1977. Multiple electrodes gave engineers a means to send different information to different places along the cochlea. It was one step in a longer collaboration among engineers, clinicians, and implant users.

A cochlear implant can have multiple electrodes and still struggle to make speech clear. Wilson and his colleagues developed a way to pulse the channels in sequence, known as continuous interleaved sampling. The advance shows how much the result depends on how an implant encodes sound as well as on its hardware.

Phillips's Flex-Foot used a composite structure that flexed under load. His patent drawings show how the prosthetic foot and leg use that motion to store and return energy as someone steps. That is the design change to look for when comparing it with a rigid prosthetic foot.

Herr and his MIT group worked on a powered ankle-foot prosthesis that adds push-off with a motor. A spring gives some of the energy of a step back; the powered ankle can actively add energy. That difference is a useful way into the engineering behind the BiOM.

Zukas drew on his experience as a power-wheelchair user when he designed a curb ramp for Berkeley. The city used his design before California's state standards took over. His oral history explains how a person encountering a barrier could turn that experience into a practical design for a public street.