2007 Fiscal Year Final Research Report Summary
Study on automatic control of hypnosis using inhalational anesthetics
| Project/Area Number |
17560390
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Control engineering
|
|---|
| Research Institution | Kyoto University |
|---|
Principal Investigator |
FURUTANI Eiko Kyoto University, Department of Electrical Engineering, Associate Professor (40219118)
|
|---|
| Project Period (FY) |
2005 – 2007
|
| Keywords | hypnosis control / sevoflurane / propofol / Bispectral Index / drug interaction / pharmacodynamic model / model predictive control |
|---|
| Research Abstract |
In this study, a control system is developed that adjusts inspired concentration of sevoflurane, an inhalational anesthetic, based on Bispectral Index, a well-known hypnosis index, to realize a desired anesthesia for patients. Up to now, during anesthesia by an inhalational anesthetic the amount of the drug is usually administered based on exhaled breath concentration. But to realize a desired anesthesia the inspired concentration has to be adjusted based on patient's hypnosis even when both intravenous and inhalational anesthetics are used. For this purpose we study (1) a model of the effects of anesthetics that represents their interaction, (2) a hypnosis control method and an identification method of individual parameters, and (3) an actuator for adjusting inspired concentration of the inhalational anesthetic. The obtained results are as follows.
(1) A novel pharmacodynamic model that can represent the interaction of propofol, an intravenous anesthetic, and sevoflurane. The model has
… More
only eight parameters, four parameters of the propofol pharmacodynamic model and four parameters of the sevoflurane pharmacodynamic model. Simulation results confirm that the model describes the effect and the interaction of propofol and sevoflurane when the parameters are set appropriately.
(2) A model predictive control method for maintaining hypnosis at a desired level using both propofol and sevoflurane is constructed considering delay times of drug effects and upper and lower bounds of inspired concentration of sevoflurane. An identification method of individual pharmacodynamic parameters and delay time based on measured data during anesthesia induction is also developed. The hypnosis control is started after the identification. Simulation results confirm that the developed control system can keep hypnosis within a proper range.
(3) A prototype of a mounting actuator for adjusting inspired concentration of sevoflurane is developed. Medical doctors can adjust the concentration in the usual way when the actuator is mounted. Less
|
Research Products
(6 results)
