"We have been working on closed-loop systems, where drugs are administered, their effects continuously monitored, and the doses are adjusted accordingly, for the last 5 years", stated Dr. Thomas M. Hemmerling of McGill's Department of Anaesthesia and the Montréal General Hospital, who heads the Intelligent Technology in Anaesthesia research group (ITAG), a team of anaesthesiologists, biomedical scientists and engineers. "Think of 'McSleepy' as a sort of humanoid anaesthesiologist that thinks like an anaesthesiologist, analyses biological information and constantly adapts its own behaviour, even recognizing monitoring malfunction."
The anaesthetic technique was used on a patient who underwent a partial nephrectomy, a procedure that removes a kidney tumour while leaving the non-cancerous part of the kidney intact, over a period of 3 hours and 30 minutes. To manipulate the various components of general anaesthesia, the automated system measures three separate parameters displayed on a new Integrated Monitor of Anaesthesia (IMA): depth of hypnosis via EEG analysis, pain via a new pain score, called Analgoscore, and muscle relaxation via phonomyography, all developed by ITAG.
The system then administers the appropriate drugs using conventional infusion pumps, controlled by a laptop computer on which "McSleepy" is installed. Using these three separate parameters and complex algorithms, the automated system calculates faster and more precisely than a human can the appropriate drug doses for any given moment of anaesthesia. "McSleepy" assists the anaesthesiologist in the same way an automatic transmission assists people when driving. As such, anaesthesiologists can focus more on other aspects of direct patient care.
An additional feature is that the system can communicate with personal digital assistants (PDAs), making distant monitoring and anaesthetic control possible. In addition, this technology can be easily incorporated into modern medical teaching programmes such as simulation centres and web-based learning platforms.
Anaesthesia care is characterized by many biological and pharmacological parameters to monitor record and analyse. "It will probably take two years to perfect the system", Dr. Hemmerling stated. "Many people are reluctant to rely on automated systems, especially when they are not visible - it is not clear what they are actually doing or how, the fear of a 'black box' which suddenly takes over. In designing 'McSleepy', we put in considerable research on the design of an interface which is clear, easy to read, resembles displays of our everyday practice but still provides a detailed clinical picture of what is going on and what has happened."
Dr. Hemmerling hopes that a commercial system might be available within the next 5 years.