What is a kymograph?

Kymograph is an electrical device used in preclinical medical research to record the biological responses (muscular motion, change in BP, and other physiological phenomena) of various tissues. It was invented by Carl Ludwig (1847) to record the change in arterial BP. It consists of an electrically driven gear box with a vertical spindle carrying a drum, and is disengaged before changing the gear box or moving the drum manually. By convention, the drum rotates in the clockwise direction, so all kymograph records should be read from left to right.