Twitcher: A Device to Simulate Thumb Twitch Response to Ulnar Nerve Stimulation


Objective. To design and fabricate a device to simulate evoked thumb adduction in response to ulnar nerve stimulation. Methods. We implemented a computer-controlled, motorized thumb (TWITCHER) that responds to ulnar nerve stimulation by an unmodified peripheral nerve stimulator. Clinically realistic response patterns are generated for both depolarizing and non-depolarizing muscle relaxants and three modes of stimulation (single twitch, train-of-four, tetanus). Results. The device has been used in a full-scale patient simulator for the last six years. Discussion. TWITCHER has been well received by participants in simulation exercises including the use of neuromuscular blocking drugs.

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Lampotang, S., Good, M.L., Heijnen, P.M.A.M. et al. Twitcher: A Device to Simulate Thumb Twitch Response to Ulnar Nerve Stimulation. J Clin Monit Comput 14, 135–140 (1998).

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  • simulation
  • peripheral nerve stimulation
  • neuromuscular blockade
  • thumb adduction