Unidimensional fuzzy pain intensity scale

A fuzzy pain scale for representing subjectivity and emotionality related to the fifth vital sign of medical condition is proposed in this paper. The classic intensity rating scales are inherently crisp sets. The medical and healthcare community does not realize that since the concept of fuzzy sets does not range all fields of knowledge yet. This paper extends the accepted international classic pain intensity rating scales to fuzzy set theory obtaining the fuzzy visual analog scale (FVAS), fuzzy numerical rating scale (FNRS), fuzzy qualitative pain scale (FQPS), and fuzzy face pain scale (FFPS). These fuzzy pain intensity scales take into account positive characteristics concerning classic pain intensity scales meanwhile represent the inherent imprecision, uncertainty and vagueness presented in the pain report and assessment. The proposed approach demonstrates how fuzzy set theory may push forwards the boundaries of medicine and healthcare by proposing a novel approach in order to improve the human quality level.