Controlling the hypnotic drug (propofol) to maintain a stable depth of anesthesia, in dogs

The development of control and automatic systems is important to guarantee a stable anesthesia, with no under or over dosage, and no awareness episodes. In this study a controller for the Cerebral State Index (CSI — an electroencephalogram derived signal) was developed. This study was a simulation study, the CSI was modeled using a fuzzy logic model with two inputs the effect-site concentration of propofol and the electromyography (EMG). The controller was tested using constant and variable references in an exhaustive set of simulations. The controller developed presents a good performance in all simulations and the controlled variable seems to be influenced by electromyography level. A controller for propofol anesthesia for veterinary use is an important step towards the improvement of animal welfare. The overall aim is to improve animal safety and comfort.