Abstract: A gas spectrometer is provided for the monitoring of the maintenance of desired calibration conditions. The inventive method and apparatus is particularly apt for use in respiratory gas spectrometers. Monitoring may be achieved by first establishing calibration condition values obtained by passing radiation beams through a reference gas chamber and purged, sample gas chambers upon initial calibration. Subsequently, e.g. after the spectrometer has been utilized in the field, corresponding test condition values are obtained by passing radiation beams through the same reference gas chamber and purged, sample gas chambers. Comparisons utilizing the calibrated condition values and test condition values can be made to monitor calibration variances (e.g. variances, in optical pathway conditions and depletion of the radiation source(s) utilized in the gas spectrometer).

Abstract: The disclosed gas analyzer (10) provides two separate folded optical paths (16 and 18) from a single source (12) to a single detector array (14) via a polychromatic filter (26). One optical path (16) passes through a sample gas chamber (24) containing a gas to be analyzed and the other path (18) passes through a reference chamber (30) containing a reference gas. On each optical path (16 or 18), radiation from the source (12) is collected by upstream optics (22 or 28) to form a converging beam (16b, c or 18b, c), thereby reducing or eliminating the need for collection optics at the detector array (14).

Abstract: A method and computerized system for ECG data review and analysis are provided. In preferred embodiments, a transformation is performed on beat data and the transformed data are categorized into beat "bins." The clinician/user may select sensitivity to vary the number of bins created by the system. Once beats are preliminarily assigned to bins by the system, the clinician/user may review beats by bin and reassigned beats as desired. In preferred embodiments, recategorization is accomplished by "dragging" a beat to a new bin with the aid of a pointing device or "mouse." In preferred embodiments, a superimposition mode allows dynamic review of beat graphs with automatic detection, color coding, and optional pause at abnormal beats. Audio information is also preferably provided to aid the clinician/user in detecting abnormal beats. A P-wave marker capability is also provided to give a constant reference point during beat review in the superimposition mode.