This is a device for measuring sensitivity to pain. It can be a simple hand-held device such as very thick Semmes-Weinstein monofilaments, or it can be a robotic device such as The Woodpecker.
Algometer used by, Holmes and Head (1911)
This was a pressure algometer device consisting of a metal cylinder containing a spring attached to a plunger and having a flat tip. It was used to test pressure pain thresholds. (For further information see: Chapter 2.9 Quantitative sensory testing D. Yarnitsky and D. Pud, C.D. Clinical Neurophysiology, Volume 1 (Revised and Enlarged Edition) Binnie, R. Cooper, F. Mauguie`re, J.W. Osselton, P.F. Prior, B.M. Tedman (Editors) EMG, Nerve Conduction and Evoked Potentials, http://126.96.36.199/ra/blue/file/4238-002-009.pdf.)
This is a mechanical algometer for testing pain thresholds for fingers. It was developed by Keele who noted that the “hand-operated pressure gauge is a relatively crude instrument and the technique of using it varies. To control the method and to refine the technique, I devised the finger algometer. The finger algometer (Fig 3): The finger is used instead of the forehead. The exact site can be found and retested on several occasions. Ten sites can be used for each subject on any one occasion. Pressure is provided by compressed air delivered into the syringe. A wide range of pressures can be selected and different rates of increase in pressure can be used. When the end-point is reached, the pressure can be released at once by the subject using a valve and the pain threshold read off a gauge by the observer.” (Measurement of Pain and Analgesia, C A Keele Page 73-78 Proceedings of the Royal Society of Medicine, year unknown, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1900645/pdf/procrsmed00174-0077.pdf.)
This is an early mechanical/pressure algometer.
McDougall used this device to measure mechanical pain in subjects during the historic expedition to the Torres Straights. He found that the locals were different than Englishmen.
On individual sensitivity to pain. Harold Griffing, Psychological Review, Volume 3, 1896, Page 412-415, https://books.google.ca/books?id=kIa3AAAAIAAJ&dq=cattell+pressure+algometer&source=gbs_navlinks_s.