Abstract: A respiratory gas flow rate sensor having a gas flow channel includes: a thermo-resistive sensing element located in the flow channel to detect rate of flow; an identification resistor electrically coupled to the sensing element, and an electrical interface to facilitate electrical connection of the flow sensor to a controller arranged to determine the identification resistor value and thereby identify the flow sensor type. A respiratory gas flow sensing system is also provided that includes: a gas flow sensor as noted above; and an electronic controller electrically connected to the gas flow sensor and arranged to determine the identification resistor value and thereby identify the flow sensor type.

Abstract: The accurate measurement of inspired and expired gas volume flow and gas composition are important in respiratory therapy. The invention provides a gas flow sensor for a ventilator comprising: a flow path extending between a first end that connects to a supply of gas and a second end that couples to a patient airway interface; and a constant temperature anemometer sensor arranged within the flow path between those ends. It further comprises a sampling port that may be coupled to a gas analyser device; and an orifice which is in fluid communication with the flow path and the sampling port so that, in use, gas may be drawn from the flow path for analysis, the gas being drawn from the flow path at a position located between the anemometer sensor and the first end.

Abstract: The accurate measurement of inspired and expired gas volume flow and gas composition are important in respiratory therapy. Combining the two measurement functions often results in excessive deadspace and/or in the two measurement systems adversely affecting each other. The invention provides a gas flow sensor (19) for a ventilator comprising: a flow path (22) extending between a first end that connects to a supply of gas and a second end that couples to a patient airway interface; and a constant temperature anemometer sensor (23) arranged within the flow path between those ends. It further comprises a sampling port (5) that may be coupled to a gas analyser device; and an orifice (24) which is in fluid communication with the flow path and the sampling port so that in use gas may be drawn from the flow path (22) for analysis, the gas being drawn from the flow path at a position located between the anemometer sensor and the first end.