The<unk>  is a device for patients to record their level of pain by illuminating a strip of light emitting diodes proportional to the pain they are feeling. It is one way of eliminating observer bias. E. A. Welchew developed a similar system in 1982.
King's pain recorder
Pain ladder
Pain scale
Schmidt sting pain index
Textbook of Pain
Baroreflex
Gait analysis
Pressure measurement