Abstract: A breathing apparatus includes a tube having a proximal end connected to a breathing mask and a distal end connected to a splitter. A first branch has a proximal end connected to the splitter and an open distal end. A first sensor is arranged within the first branch and operatively connected to a processing module. A first flow control valve is arranged in the first branch and operatively connected to the processing module. A second branch has a proximal end connected to the splitter and a distal end connected to an inflatable reservoir. A second sensor is arranged within the second branch and operatively connected to a processing module. A second flow control valve arranged in the second branch and operatively connected to the processing module. The breathing apparatus can adjust a pneumatic resistance according to a programmed training protocol and counteract hyperventilation by recirculating exhaled air.

Abstract: A breathing apparatus includes a tube having a proximal end connected to a breathing mask and a distal end connected to a splitter. A first branch has a proximal end connected to the splitter and an open distal end. A first sensor is arranged within the first branch and operatively connected to a processing module. A first flow control valve is arranged in the first branch and operatively connected to the processing module. A second branch has a proximal end connected to the splitter and a distal end connected to an inflatable reservoir. A second sensor is arranged within the second branch and operatively connected to a processing module. A second flow control valve arranged in the second branch and operatively connected to the processing module. The breathing apparatus can adjust a pneumatic resistance according to a programmed training protocol and counteract hyperventilation by recirculating exhaled air.

Abstract: A sensor and method for measuring respiratory gas properties are presented. A thermal conductivity sensor is used to measure the thermal conductivity of a gas with unknown composition and/or mass flow rate at different temperatures. The measured thermal conductivities at different temperatures are compared with known thermal conductivities of gases at different temperatures. In an exemplary application the sensor and method are installed in a tube to determine a mass of respiratory air flowing through the tube and a concentration of CO2 therein.

Abstract: A sensor and method for measuring respiratory gas properties are presented. A thermal conductivity sensor is used to measure the thermal conductivity of a gas with unknown composition and/or mass flow rate at different temperatures. The measured thermal conductivities at different temperatures are compared with known thermal conductivities of gases at different temperatures. In an exemplary application the sensor and method are installed in a tube to determine a mass of respiratory air flowing through the tube and a concentration of CO2 therein.