| Abstract | The characteristics of a microcomputer-based system for measuring
ventilatory
parameters in neonates on mechanical ventilatory assistance are described.
The tidal flows of the infant are sensed by a
pneumotachometer housed in the wall of a constant pressure plethysmograph.
The processed signal from the pneumotachometer is fed to a dedicated
analog-to-digital converter and 6502 microcomputer, which, in turn, loads a
dual ported RAM buffer with smoothed, digitized, tidal flow data. At the
end
of each minute the Apple 2+ processes the accumulated data and computes
tidal
volume, respiratory frequency, minute volume and the difference between
inspired and expired volume. Numerical outputs for these variables and a
histogram, representing the distribution of tidal volumes for the minute,
are
printed on a dot matrix printer. This inexpensive system is capable of
presenting contemporary, summarized, ventilatory data in a form that is
potentially very useful for the clinicians who are managing the care of the
infant. |