Category: Misc. Diagnostic
Estimated Date: 1930
Name: Electrocardiograph
Manufacturer: Cambridge Instrument Company
Description: Wooden case contains a string galvanometer with magnets in housing, knob to adjust string. Light shines through housing to enter a box containing light sensitive paper. A mirror refects a scale into the box as well and paper advances into a drum, which can be closed and removed. there is a counter. Pat date 1911 and gear mechanism to advance paper and counter and a timer wheel.
Reference 1: 417