A sphygmograph or pulsometer was an old medical instrument for recording the movements of the arterial wall during and between the pulse beats. One of the earliest forms was invented by Marey, and consists of a lever with an elastic spring. One end of the spring is placed on the radial artery, and has above it a rack and pinion attached to a lever. The other end of the lever carries a style, which records on a moving smoked plate the movements of the vessel wall. The smoked plate is moved at a known rate by clockwork, and the pressure of the spring upon the artery can be regulated by a screw. Research Sphygmograph
In machinery, a rack is a straight or slightly curved bar; with teeth on one of its edges. Adapted to work into the teeth of a wheeled cog (a pinion), for the purpose of converting a circular motion into a rectilinear motion or vice versa. Research Rack And Pinion
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Sphygmograph
