Does anyone know if people have made serious attempts to do objective pain quantification? Of the ideas that come to mind, strategy 1 would be: let the patient press buttons that give her electrical shocks and let the patient say "This shock is worse than my pain, that shock is less bad, therefore my pain is between these two levels". (I once read about an early electrical scientist who would measure voltage by shocking himself and comparing the pain with known quantities. Googling, I find that "Kenneth Catania" has done this very recently to measure eels' output...) Strategy 2 would be to somehow observe pain nerves and/or the brain directly; I don't know if this is possible. Strategy 3 would be to describe hypothetical sources of pain and ask what the patient would prefer, though even a patient trying her best may not be able to correctly compare felt pain vs. imagined pain.
Wikipedia isn't much help[1]. It lists 30+ "pain measurement scales", but clicking a few of them doesn't tell me any specifics about how they work.
Looks like someone has in fact tried strategy 1. https://www.hindawi.com/journals/js/2018/6205896/ mentions: "Recently, a quantitative pain-assessing method using electrical stimulation was introduced [12–15]. PainVision™ devices measure perception threshold and pain produced by an electrical current. This system quantifies pain intensity by comparing the experienced pain with the intensity of electrical perceptions. The perception threshold indicates the minimal electric current sensed by the individual, and the pain produced is defined as the maximal electric current sensed by the individual. However, the skin resistance of an individual may affect the electrical measurement result [16–20]."
Their refinement continues: "our system measures from the patient’s skin resistance before measuring the pain." "In this work, we developed a pain measurement device that has two analysis methods, electrical stimulation and applying pressure, for more accurate cross-validation assessment. During electrical stimulation, electrical stress is applied on a nonpain site and then the observed stress can be compared to pain. ... During the pressure evaluation, pain was assessed by applying pressure on the pain site. Inflammation was induced on the rat’s hind paw by carrageenan, and then the inflamed hind paw was stimulated by a hand-type pressure stimulator. The pressure site was then compared with the inflammation levels." Seems like it might be workable.
Wikipedia isn't much help[1]. It lists 30+ "pain measurement scales", but clicking a few of them doesn't tell me any specifics about how they work.
Looks like someone has in fact tried strategy 1. https://www.hindawi.com/journals/js/2018/6205896/ mentions: "Recently, a quantitative pain-assessing method using electrical stimulation was introduced [12–15]. PainVision™ devices measure perception threshold and pain produced by an electrical current. This system quantifies pain intensity by comparing the experienced pain with the intensity of electrical perceptions. The perception threshold indicates the minimal electric current sensed by the individual, and the pain produced is defined as the maximal electric current sensed by the individual. However, the skin resistance of an individual may affect the electrical measurement result [16–20]."
Their refinement continues: "our system measures from the patient’s skin resistance before measuring the pain." "In this work, we developed a pain measurement device that has two analysis methods, electrical stimulation and applying pressure, for more accurate cross-validation assessment. During electrical stimulation, electrical stress is applied on a nonpain site and then the observed stress can be compared to pain. ... During the pressure evaluation, pain was assessed by applying pressure on the pain site. Inflammation was induced on the rat’s hind paw by carrageenan, and then the inflamed hind paw was stimulated by a hand-type pressure stimulator. The pressure site was then compared with the inflammation levels." Seems like it might be workable.
[1] https://en.wikipedia.org/wiki/Pain_scale