A fine Marey’s sphygmograph, the precursors to the ECG and sphygmomanometer which was used to monitor the pulse and heart rhythm.

This is the most pristine example I have seen and would have been one of the last models ever made dating to the late 19th or possibly early 20th century. The maroon velvet lined box is marked in gold embossed letters “Ch. Verdin, G. Boulitte Sr. 7, Rue Linne Paris”. One open compartment accommodates the frame for the brass plate a second closed compartment contains the two original styluses. The body of the main is marked “Boulittes 7 Rue Linne Paris” and with the CBT trademark. The point which rests on the radial pulse is made from polished ivory. The arm rest is made with plated metal line with grey felt and the original black silk ribbon which would secure this to the patient’s arm is still present. The clockwork and pulley mechanisms remain in perfect working order.

• From the Phisick collection