Computer control of physiological states of patients under and after surgical operation

We have been engaged in developments of computer control systems to regulate various physiological states of patients under or after surgical operation. We started the research in 1991 in cooperation with surgeons and anesthesiologists. We first tried hypotensive control of the blood pressure of patients under surgical operation. The system was clinically applied to 34 cases since 1995 with the approval of the Ethics Committee of Kyoto University Hospital. As a result, we succeeded in decreasing the blood transfusion and the operation time roughly to the half and to the two thirds, respectively, in average. Based on this experience, we continued the research and developed the hypnosis control system that is under clinical application at the Day Surgery Unit of Kyoto University Hospital at present. We are now working for improving this system as well as trying new applications such as blood sugar control of patients after surgical operation. In this paper, our experience is introduced from the view point of complex-system control engineering.