Fuzzy control of postoperative pain

Post-operative pain is difficult to model, this difficulty being due to non-linearity, time varying behavior and intro and inter-patient variability. In this study, we describe the application of a two-stage fuzzy controller in the relief of post-operative pain. In the first stage, a fuzzy system operates until the required set-point (i.e. no pain) is attained, following which a CACI system, operating about the set-point, is used to avoid an increasing plasma concentration of opiate. The controller has been implemented in OPS-83 and in Microssoft-C.