Replacing vacuum tubes with transistors — and shrinking the instruments (1958)

Not changing the parts, but changing the design

To file this away as a company riding the technological tide is to take it far too lightly. The Nihon Kohden of 1958 had 83 employees and had posted its first profit, $10,833 (¥4m), only two terms earlier; both of its mainstays, the electrocardiograph and the electroencephalograph, were built on the assumption of vacuum tubes. Deciding to replace their insides was equivalent to throwing away the existing designs. That the company set out its first three-year plan in the same year, and reorganized to separate engineering from design, suggests that Ogino Yoshio saw this as a problem of design rather than of components.

The judgment did not bear fruit quickly, however. Nearly two years passed between the successful substitution and the launch of the MC-1TR electrocardiograph, and vacuum tubes survived in places such as the high-sensitivity pre-amplifier. Mass production itself was a change driven from outside the company. Even so, a calibration-voltage circuit that needed no battery, and a miniaturized recording galvanometer, could only have come out of that rebuild. How fast can a company pull a part that arrives from outside into its own design? The 1958 shift was a test of exactly that speed.