Redefining Mobility and the Swail Sensor, 1964-1966

Swail Sensor, CSTM artifact no. 1985.0809.001

Swail Sensor, c.1966

By 1964, the NRC began officially cooperating with several agencies, including the Canadian National Institute for the Blind (CNIB), to develop aids that would help in the vocational training and education of people who were blind or partially sighted. If such devices were designed and successfully implemented, NRC scientists like Swail believed they would significantly improve people’s chances of employment and social integration.[1]

 With this new program came a number of initiatives, especially in terms of mobility. One’s ability to navigate the world around them is undoubtedly crucial for establishing and maintaining independence, as well as ensuring safe learning and working conditions. Swail and his colleague David S. Hewitt, another scientist with the NRC, constructed a number of devices for this purpose. As they insisted, people who are blind or partially sighted “like any other consumer” must be provided “with a variety of mobility systems to suit the needs and abilities of different persons…” The inventor, in turn, must give “careful thought” into both “the manner in which the mobility device provides its coded information to the blind traveller,” as well as “the size, weight and package of the device.”[2] In other words, assistive devices must effectively communicate the information they are intended to convey, and they must ideally be compact, light-weight and unobtrusive. Swail and Hewitt placed the different devices they designed within three broad categories: “obstacle detection”, “orientation” and finally,  “some means of identifying printed signs and route markers such as street names and bus numbers.”[3]

 The Swail sensor, pictured here, was one of several devices they designed for this purpose. Developed in 1966, it consists of a small, hand-held enclosed metal cylinder with four holes positioned near a plastic cap – underneath the cap being a tan conical detector. The device vibrates and emits a signal or clicking nose when it detects light and shadow. It easily fits within a pocket. The device was intended to indicate to its user that they were approaching a light or lighted area. Perhaps more importantly, the device could be used to detect print on a sign or street signal. The device had limited capacity and could not decipher the specific shape of actual letters or numbers. It was, nevertheless, an important step in developing the range of mobility devices that Swail and his colleagues endeavoured to provide.[4]



[1] James Swail, “Research on Mobility Aids for the Blind,” Reports on Sensory Researches (Ottawa ON: National Research Council of Canada, 1966), 235.

[2] James Swail and David S. Hewitt, "An Ultrasonic Obstacle Detector for the Blind," Bulletin of the Radio and Electrical Division National Research Council of Canada 20, no.3 (July-September 1970): 12.

[3] Ibid.,13.

[4] Swail sensor, artifact no. 1985.0809.001, Collections Supplementary Report, Canadian Science and Technology Museum, Ottawa ON, Canada.http://techno-science.ca/en/collection-research/collection-item.php?id=1985.0809.001