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Neural Controlled Ventilation

If long-term immersion in synthetic, computer mediated environments is going to be achieved, one of the more critical components, is taking care of the all-but-discarded physical shell that still serves as the brain's life support mechanism. After all, without that, the brain cannot live. Even the most disfigured, dismembered, or quadriplegic body can at least still handle that, even if it is completely useless at allowing the person to live a normal life.

Thus, we have a necessity to develop technologies that can monitor and maintain the health of a person's physical shell, whilst their mind is engaged in controlling a synthetic body: online, or perhaps a waldo-robot. Both technologies are certainly feasible.

One of the first steps towards such a system of body maintenance has been created, in the form of a ventilator system that reads the brain's own neural commands to the lungs, and steps in to assist if the lungs cannot take up the slack.

Designed initially with infants and premature births in mind, the NAVA or Neurally Adjusted Ventilatory Assist technology was developed by a firm going by the name of MAQUET Critical Care, in Brussels, Belgium. The idea is simple: With conventional mechanical ventilation, there is frequently a battle between the ventilator and the person being ventilated, as the ventilator forces a set amount of air into the lungs. Sometimes the body fights the ventilator so strongly, that the person has to be sedated to avoid them ripping their lungs apart as they often try to exhale full volumes of air as the ventilator is pumping more in.

This is because conventional mechanical ventilators sense a patient effort by either a drop in airway pressure or a reversal in flow. The last and most slow reacting step in the chain of respiratory events is used to sense the patient effort. Hence, creating a system that is sensitive to hyperinflation, intrinsic PEEP and secondary triggering problems.

The NAVA system on the other hand, actually reads the nerve impulses coming down the vagus nerve to the diaphragm, and to the lungs. The ventilator then supplies air equal to the amount the body should receive, minus the amount brain has asked for from the sedentary lungs. In this way, a gradual wasting of the diaphragm, common in those immobile for extended periods, is avoided. It continues to push against lungs just as full of air as they would be in an active physical lifestyle, maintaining health.

One of the additional side effects is that, because a neural stimulated ventilator breathes in perfect rhythm to the patient, regardless of the pattern of the user's breath, there is nothing to fight. Additional air is always supplied as the person is breathing in, and stops inhaling when they do. Of course, if anything were to happen to the brain, such that it stopped transmitting, then the ventilator would stop as well. However, it is doubtful that air would exactly be required in that circumstance.


Ventilation Provided By Brain Signals Helps Infants in Critical Condition (PDF)

Institutional experience of NAVA in neuro and cardiovascular intensive care patients (PDF)

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