An air flow sensor comprises a flexible resistive element permanently affixed to a flexible substrate. The air flow sensor is positioned in an inlet for airway to be monitored such that the sensor covers the inlet at all times other than during inhalation. When a vacuum is applied to the airway, a resulting...http://www.google.com.tw/patents/US7607435?utm_source=gb-gplus-share專利 US7607435 - Gas or liquid flow sensor
