United States Patent  5,730,140
Fitch; William Tecumseh S.   March 24, 1998

excerpt

Although we discuss heart and breathing sounds in this preferred embodiment,
one skilled in the art could easily adapt other realistic sounds as well.
For example, a common and serious problem in anesthesiology is vomiting by
the unconscious patient, which can block the airway and lead to dangerous
respiratory complications. Such a situation could easily be signaled by a
synthesized vomiting sound, using FOF synthesis (CSound manual, Barry
Vercoe, MIT), with the quantity, nature, and location of the vomitus as
piggyback variables. Similarly, synthesized coughs (short noise bursts fed
to a speech synthesizer) could serve as alarms, indicating various types of
respiratory complications. The realistic sound need not be a bodily sound:
for example, the sound of some operating room device, such as a ventilator
or blood gas analyzer could also be suitable. Accordingly, the description
below is simply the current preferred embodiment of the system, which is not
limited to the description below but instead by the claims which follow.


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