Patent ID: 7108659

Claim:
A respiratory analyzer for determining a respiratory parameter of a subject, comprising: a respiratory connector, through which the subject breathes; a filter module, in fluid communication with the respiratory connector, through which respired gases pass as a subject breathes through the respiratory analyzer, the filter module including a pathogen filter; a flow tube, enclosing a central flow pathway, the flow tube having a first end and a second end, a first end portion proximate to the first end, and a second end portion proximate to the second end; a chamber, in fluid communication with the filter module, surrounding the first end portion of the flow tube, the chamber and the central flow pathway being in fluid communication through one or more apertures in the first end portion of the flow tube; a wind guard connected to an external surface of flow tube and having a flared portion extending beyond the second end of the flow tube, wherein the wind guard encloses an atmospheric chamber surrounding the second end portion of the flow tube, the atmospheric chamber opening to the atmosphere through an atmospheric aperture bounded by the wind guard and having a diameter greater than the external diameter of the flow tube, the atmospheric chamber and the central flow pathway being in fluid communication through one or more apertures in the second end portion of the flow tube; a gas sensor, providing a gas sensor signal responsive to a partial pressure of a predetermined gas within the central flow pathway; a flow meter, providing a flow meter signal correlated with a flow rate of gases within the central flow pathway; and a computation module, receiving the flow meter signal and the gas sensor signal, and operable to compute the respiratory parameter of the subject.