A Computer System for Measuring the Relationship of Smell and Pain

Smell is popularly believed to influence pain, even though several of these claims currently lack significant scientific or engineering support. This paper proposes a computing system for conducting smell vs pain experiments using a laboratory-built olfactometer together with cold pressor test (CPT) and pressure pain threshold (PPT) measurements. We conducted CPT and PPT experiments for three different types of smells: pleasant, sweet, and unpleasant. Pain threshold and pain tolerance of the participants were recorded and analyzed. These results concluded that sweet and pleasant smells can increase pain tolerance while unpleasant smells can decrease pain tolerance. In conclusion, applications of sweet and pleasant smells may be a beneficial addition to the management of pain symptoms. The results are relevant for workplaces where many people suffer from musculoskeletal pain, as well as in clinical settings where pain patients are treated. The key novelties of this paper are as follows: Firstly, we proposed a computer-controlled hardware system that can be used for smell vs pain experiments; secondly, we proposed a PPT and CPT combined testing method for smell vs pain experiments; and thirdly, we validated the effects reported for CPT in previous research using different odorants.