| 摘要 |
A ventilator includes a sensor to monitor a characteristic associated with the delivery of gas to the patient, such as pressure. A sensor power supply ( 100, 130 ) is feeding a sensor in the form of a Wheatstone bridge. A first end ( 104 ) of the bridge is coupled to a first positive voltage source ( 112, 142 ) and a second end ( 116 ) is coupled to a second positive voltage source ( 118, 156, 180 ). A capacitor ( 120 ) is coupled to the second end of the bridge. A controller ( 50 ) controls the first and the second positive voltage sources so as to (a) disable the sensor by causing the first positive voltage source to provide substantially zero voltage to the first end of the Wheatstone bridge and by causing the second positive voltage source to provide a positive voltage to the second end of the capacitor, and to (b) enable the sensor by causing the first positive voltage source to provide a positive voltage to the first end of the Wheatstone bridge and by causing the second positive voltage source to provide a decreasing voltage to the second end of the capacitor. |
