The Pacemaker
The year was 1949. Dr. William Bigelow and Dr. John Callaghan at the Banting and Best Institute laboratory in Toronto were studying how extreme cold could slow the human heart rate thus making it possible to conduct open heart surgery. Although their work had led to a number of successful open heart surgeries, they were stuck on the problem of how to re-start the heart if it were to stop.

The Pacemaker -- Helping Millions

The Pacemaker -- Helping millions of people lead normal, healthy lives! (Corbis)

 Enter Dr. John Hopps, electrical engineer and National Research Council researcher. Working with the two physicians, John Hopps, P. Eng. and his team found that applying a gentle electrical stimulus to the heart would not only duplicate the normal body nerve stimulation but it would also not cause any harm to the heart muscle. In addition, this technique would start a stopped heart and increase or decrease the heart rate, as required.

The first pacemaker was developed in 1950.  It was large (about 30 cm long, and several centimetres high and wide), the pulses were generated by vacuum tubes and the entire unit was powered by 60 Hz household current. Its size meant that it wasn't of immediate practical use but with the advent of transistors and reliable batteries, the package grew smaller until a pacemaker was successfully implanted in the chest of a Swedish man in 1957. They have since become a common medical tool.

NRC -- New Improvements to the NRC Pacemaker

Pacemakers --Photos and descriptions of some early Pacemakers

Other sites for information on the Pacemaker:

Canadian Medical Hall of Fame -- Dr. Wilfred Gordon Bigelow