[Fuzzy logic and postoperative pain].

Objective: To apply a fuzzy logic expert control system for the treatment of postoperative pain in a clinical setting.

Material And Methods: A system was designed consisting of a perfusion pump guided by a fuzzy logic computer interface to regulate the perfusion of alfentanil in accordance with the patient's pain response. The system was also equipped with a safety device that halted perfusion in case of desaturation, bradypnea or heart rate or blood pressure variations greater than 25%. The system was used in the first 90 minutes after surgery in a patient who underwent bilateral saphenectomy.

Results: All system functions worked properly, maintaining the target analgesic values (visual analog scale < or = 2) 77% of the time.

Conclusion: It is possible to use fuzzy logic to obtain adequate treatment of postoperative pain.