Intermittent oxygen delivery system and cannula

Abstract

An improved system for delivering oxygen on demand to a user comprises a pressure transducer for sensing pressures during the breathing cycle of a user and for creating an electrical signal proportional to said sensed pressures, an electronic amplifier for amplifying the signal to at least 10,000 times the original signal strength, electronic filters for regulating the amplitude of the signal and for correcting the point of the signal where expiration stops and inspiration begins to correspond to zero respiratory pressure, an on/off switching circuit and cooperating valve drive circuit for switching to an on condition in response to a preselected first pressure and to an off condition in response to a preselected second pressure, and a valve driven by the valve drive circuit means for directing oxygen from an oxygen source to a user.

Dependencies are inferred from the claim text.