Apparatus for measuring a flow quantity difference between an inspiratory incoming flow and an expiratory outgoing flow in a breathing apparatus using the ouputs of a voltage splitter

摘要

The apparatus has a first resistive flow sensor (1) in the ingoing flow (3) and a second resistive flow sensor (2) in the outgoing flow (4). An analysis device determines the flow difference. A first Wheatstone bridge has first and second branches forming voltage splitters between a supply voltage and a reference voltage. The first flow sensor is provided as a resistive element in the first branch and the second flow sensor (2) is a resistive element in the second branch. The analysis device takes the voltage differential between the outputs of the voltage splitters of the first and second bridge branches as an input signal to determine the flow difference. Independent claims also cover a method of determining the flow difference.