Estimated Date: 1920
Description: 6 78” x 6 3/8” x 2 3/8” red velvet line black leatherette box contains 6” x 3 1/2” x 2” sphygmograph in two parts. The wrist strap is separate and is a metal platform, which attaches to the instrument and leather strap with six boot like eyelets that can be laced closed, the instrument has a screw for adjusting the pressure on the arm of a pressure sensor, a rectangular portion containing clockworks to run the paper and timer and needle for pulse recording. In addition, differing from the others shown on the website there are two complex pressure sensors activated by air pressure from connections to drums that move two other needles (one missing) by a bellows like motion to sense pressure from other organs. It is listed in Verdin as manufactured by Boulitte and as a sphygmocardiographe, but the one shown there has only on extra pressure sensing device, not two.
Reference 1: 415