The pulsemeter.
Westhorpe
R N
RN
Geoffrey Kaye Museum of Anaesthetic History.
Ball
C
C
D000776:Anesthesiology / Q000266:history* / Q000295:instrumentation*; D004867:Equipment Design; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D008991:Monitoring, Physiologic / Q000266:history* / Q000295:instrumentation*; D011674:Pulse / Q000266:history* / Q000295:instrumentation*