BREATH SYNCHRONIZATION CONTROL UNIT FOR GAS FEEDER

摘要

A breath synchronisation control unit for gas feeders which is capable of feeding a gas upon detection of expiration without fail and does not break even by the misuse thereof which is liable to occur frequently in daily use. The control unit is used in a gas feeder to control the feed of a gas supplied from a gas source in synchronization with breath. The unit is provided with a breath detector comprising a platy piezoelectric element supported by a substrate at one or both ends thereof and contained in a vessel having an external gas passage formed in the place opposite to the plane of the piezoelectric element and a breath passage formed in the place in parallel with the plane for detecting a pressure change of the air introduced through the respective passages to generate electric signals, a duct joined to the breath passage to cause the expiration to act upon the inhalation and to flow a gas at the time of expiration, an electromagnetic valve provided in the duct to join the gas source to a closed port at all times, and a control unit for joining the gas source to the duct for a given time and breaking the junction between the breath detector and the duct by operating the valve when the state of expiration is detected by the electric signals generated by the breath detector.