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Real-time closed-loop control in a rodent model of medically induced coma using burst suppression
ShiNung Ching1, Max Y Liberman, Jessica J Chemali
1* Research Fellow, Department of Anaesthesia, Harvard Medical School, Boston, Massachusetts; Research Fellow, Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts; Research Affiliate, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts. † Research Assistant, Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital. ‡ Instructor, Department of Neurology, Harvard Medical School; Assistant in Neurology, Department of Neurology, Massachusetts General Hospital. § Assistant Professor, Department of Anaesthesia, Harvard Medical School; Assistant Anesthetist, Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital; Research Affiliate, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology. ‖ Instructor, Department of Anaesthesia, Harvard Medical School; Instructor, Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital; Research Affiliate, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology. # Warren M. Zapol Professor of Anaesthesia, Department of Anaesthesia, Harvard Medical School; Anesthetist, Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital; Professor of Computational Neuroscience, Edward Hood Taplin Professor of Medical Engineering, Institute for Medical Engineering and Sciences, Department of Brain and Cognitive Sciences, Harvard-MIT Health Sciences and Technology Program, Massachusetts Institute of Technology.
A new closed-loop anesthetic system precisely controlled electroencephalogram burst suppression in rats. This technology shows promise for accurately managing medically induced comas in patients.
Area of Science:
- Anesthesiology
- Neuroscience
- Biomedical Engineering
Background:
- Medically induced coma is crucial for treating status epilepticus and traumatic brain injuries.
- Current methods require precise anesthetic control to manage profound brain inactivation.
- The electroencephalogram (EEG) state of burst suppression is a key indicator for coma depth.
Purpose of the Study:
- To test a closed-loop anesthetic delivery system for precise EEG burst suppression control.
- To evaluate the system's ability to maintain a medically induced coma automatically.
- To assess the reliability and accuracy of the closed-loop system in real-time.
Main Methods:
- A closed-loop propofol delivery system was implemented in six rats.
- The system integrated a computer-controlled pump, pharmacokinetic modeling, and a burst-suppression probability algorithm.
- A proportional-integral controller adjusted propofol infusion based on real-time EEG data.
Main Results:
- The system achieved tight, real-time control of burst suppression for approximately 60 minutes per animal.
- The controller successfully tracked target burst-suppression probability levels and transitions.
- High reliability (0.94) and accuracy (1.00) were demonstrated across all tested levels.
Conclusions:
- Closed-loop anesthetic systems can reliably and accurately control burst suppression in real-time in rodents.
- This approach offers a potential paradigm for precise control of medically induced comas in clinical settings.
- Further research may validate this system for human patient care.
