Reading brainwaves helps select the optimal dose of anesthesia
A system has been developed that automatically adjusts anesthetic dosage based on brain activity.Researchers from the Massachusetts Institute of Technology and Massachusetts General Hospital, have developed a system that monitors the patient's state of consciousness using brain waves and adjusts anesthesia depending on the values obtained. The technology will help reduce post-operative side effects in the future.
The experimental setup tracks fluctuations in local field potential (LFP) power - low-frequency oscillations associated with the electrical activity of neurons. This is determined by bursts of neural activity that change in predictable ways depending on whether a person is awake or asleep. By continuously monitoring neural activity, it is possible to determine, based on fluctuations in LFP power, whether a person is conscious or unconscious.
The system developed by the researchers also uses a computer model that, based on a person's physiological characteristics, determines what dosage of a drug is currently required to keep them in the desired LFP range.
The researchers tested the system on two rhesus macaques. In a series of nine experiments lasting 125 minutes each, the researchers moved the animals between two levels of unconsciousness. The system automatically maintained the desired state by updating the anesthetic dose every 20 seconds.
The researchers note: more research is needed before the technology can be tested on humans. But they believe that eventually the system will allow the use of EEG analysis during surgery to quickly move patients from conscious to unconscious and back again.