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A patient with a traumatic injury to the brain will be place into a medically-induced coma, that allows the brain time to heal and dangerous swelling to subside. Brought about by using general anesthesia drugs, medically-induced comas can last for days.
In the current system, doctors and nurses need to monitor these patients to ensure they are at the right degree of sedation. A new study published within the journal PLOS Computational Biology has described an automatic system that may follow patients’ brain activity and respond accordingly with drug dosages that maintain the correct state.
“Someone has to be constantly returning and checking on the individual, to be able to hold the brain inside a fixed state. Why don’t you develop a controller to achieve that?” said Dr. Emery Brown, a professor of medical engineering at MIT.
Brown and his team started by analyzing brain waves in different states of activity: awake, asleep, sedated and anesthetized. For each state, they were in a position to pick a distinctive electroencephalogram (EEG) pattern.
When people are inside a drug-induced coma, the mind is silent for up to several seconds at any given time, that is interrupted by short bursts of activity. This pattern of activity, also known as as burst suppression, permits the brain to save necessary energy during periods of trauma.
As a patient slips into a drug-induced coma, the individual administering anesthesia drugs targets a particular quantity of “bursts per screen” as brain activity streams over the EEG monitor. This pattern needs to be established for hours or days at a time.
“If ever there have been a time to try and build an autopilot, this is actually the perfect time,” Brown said. “Suppose you’re going to fly for 2 days and I’m going to provide you with a very specific course to maintain over a long time, but I still would like you to maintain your hand around the stick to fly the plane. It simply wouldn’t seem sensible.”
To automate the monitoring process, the team constructed a communication pathway between your brain and a device made to assist various brain functions. The unit included an EEG system, a drug-infusion pump, a computer and a control algorithm. The anesthesia drug propofol was chosen to keep the brain in an ideal degree of burst suppression.
In tests on laboratory rats, the computer’s algorithm interpreted the animal’s EEG, calculated how much drug was in the brain and adjusted how much of the drug to inject in to the rodent on the second-by-second basis.
The system may also regulate the depth of a coma nearly instantaneously, which may be impossible to accomplish manually, the research team said. The machine could also be set to consider someone out of an induced coma occasionally so doctors could conduct neurological tests.
“A lot of what we should do in medicine is making educated guesses regarding what’s best for the patient at any given time,” said Dr. Sydney Cash, an affiliate professor of neurology at Harvard Medical School who had been not part of Brown’s team. “This method introduces a methodology where doctors and nurses don’t need to guess, but can rely on a pc to figure out – in much more detail and in a time-efficient fashion – just how much drug to provide.”
