Abstract: There is provided a device for measuring a person's ventilation or metabolism metrics. The device includes a conduit shaped to receive an exhalation of air therethrough. The device includes at least one gas sensor passively sampling said exhalation of air by means of a positive or negative pressure differential. The device includes a pump configured to assist in said passive sampling. The pump is configured to adjust the flow rate of a sample portion of said exhalation of air passing through to the at least one gas sensor, so as to be proportional or linear within a predetermined threshold, to the flow rate of the exhalation of air passing through the conduit. The device is configured to operate via both breath-mixing and breath-by-breath modes using a single flow path. The device is configured to change between the breath-mixing and breath-by-breath modes as a function of operation of the pump.

Abstract: There is accordingly provided a device for measuring a person's ventilation including oxygen consumption. The device includes a breathing conduit with at least one sensor sampling port. The device includes a dehumidification conduit extending from the sensor sampling port towards a sensor. The dehumidification conduit has a proximal end portion flush with the sensor sampling port. The dehumidification conduit has a longitudinal axis about which the proximal end portion thereof extends. The breathing conduit is shaped to promote a flow of air adjacent the sensor sampling port in one or more directions perpendicular to the longitudinal axis.

Abstract: There is provided a device for measuring a user's oxygen-consumption. The device includes a tubular member with a first tapered portion through which an exhalation of air enters into the device, a second tapered portion, and a constriction between the portions thereof. The devices includes a flow sensing mechanism in communication with the first tapered portion of the tubular member. The device includes an oxygen sensor in communication with the first tapered portion of the tubular member. The device is configured such that the oxygen sensor is passively supplied a portion of the exhalation of air by means of positive or negative differential pressure referenced between the first tapered portion and at least one of ambient air and the constriction of the tubular member.

Abstract: There is provided a device for measuring a user's oxygen-consumption. The device includes a venturi tube. The venturi tube has a first tapered portion, a second tapered portion that is more tapered compared to the first tapered portion, and a constriction between the portions thereof. The device includes at least one pressure sensor in communication with the constriction and the first tapered portion of the venturi tube. The device includes an oxygen sensor in communication with the constriction and the first tapered portion of the venturi tube.

Abstract: The present invention relates to a device for measuring a person's ventilation. The device includes a conduit with an exhaled-air receiving portion and an inhaled-air receiving portion. The device includes pressure and oxygen sensor sampling ports. The sampling ports are in fluid communication with the conduit. The device includes a deflector disposed within the conduit. The deflector is configured to deflect air exhaled into the exhaled-air receiving portion of the conduit away from the sensor ports.

Abstract: There is provided a device for measuring a user's oxygen-consumption. The device includes a venturi tube. The venturi tube has a first tapered portion, a second tapered portion that is more tapered compared to the first tapered portion, and a constriction between the portions thereof. The device includes at least one pressure sensor in communication with the constriction and the first tapered portion of the venturi tube. The device includes an oxygen sensor in communication with the constriction and the first tapered portion of the venturi tube.