The June Advertisement of the Month is A Tektronix 502 Oscilloscope for use in the operating room. This ad depicts a Tektronix Type 502 dual-beam oscilloscope being used in a surgery suite at North Carolina Memorial Hospital in Chapel Hill. An anesthesiologist is monitoring the patients' blood pressure and ECG (electroencephalogram) traces simultaneously in real time.
The ad ran in the Fall issue of American Scientist in 1962.

In the late 1950s and 1960s, with the rise of specialized coronary care units in leading hospitals, oscilloscopes and their derivatives became standard equipment for patient care. A surgeon or an attending nurse could see defibrillation or arrhythmia as it was happening. Tektronix offered an option where a longer persistence CRT phosphor could be ordered that would let the waveform remain onscreen long enough for comfortable viewing. The 502's new dual-beam CRT allowed for tracking two signals onscreen.

The 1 MHz 502 was introduced in the May 1958 catalog, selling for $825. It was in response to the HP130A, one of the first two Hewlett Packard scopes offered in 1956. The 130A's modest bandwidth of 300 kHz appealed to many of HP's existing customers and responded to a relatively low-bandwidth market void that Tektronix had ignored to that point.

With the benefit of a new vertical amplifier and enhanced CRT deflection, the 502's peak sensitivity exceeded the HP scope by a factor of five, making it very attractive for biological and medical applications where bandwidth was not as much an issue. Tektronix oscilloscopes dominated use in cardiology research from the early 1960's on, while purpose-built instruments were used for routine bedside and surgical cardiac monitoring. One of the concerns for using an off-the-shelf oscilloscope in an operating room setting was the presence of flammable anesthetics such as ethyl ether or cyclopropane. A standard oscilloscope's high-voltage power supply was considered an ignition source.

In 1967 Tektronix introduced the 410 Physiological Monitor, the first of a line of medical products. Tektronix sold the medical products business to Squibb Corporation in 1980.

Advertisements of the Month: Sept 2025 - Present.