EKG.

Heart activity is measured by the electrocardiogram, or EKG (the K is from the original German spelling), which measures cardiac electrical activity with an array of suction cups and disks placed on the patient's chest and limbs. At the beginning of the decade the EKG machine was a bulky and sensitive piece of equipment that was used strictly in hospital settings or in the offices of specialists. In 1964 the Public Health Service began local testing in the Washington, D.C., area for a more convenient method of obtaining an EKG. A nurse could go to the patient's home in Alexandria, Virginia, with a nine-pound box, place four electrodes on the patient's chest, phone George Washington University Medical School, put the phone's mouthpiece on a receptacle attached to the box, and record the results on a university computer.

Less Bulky System.

Honeywell made Cardioview, the box for this function, that took...