Blood alcohol concentration measuring from respiratory air
First Claim
1. A method for obtaining a reliable blood alcohol concentration value from respiratory gases of a subject undergoing examination, the subject respiring gases in a respiratory cycle having an exhalation phase with exhalation stages, a respiratory cycle exhalation phase suitable for providing a reliable blood alcohol concentration value having a plateau stage, the plateau stage having a beginning and a concluding portion, respiratory gases of the subject exhaled in the plateau stage comprising alveolar gas of the subject, said method comprising the steps of:
- sampling the respiratory gases of the subject during the exhalation phase to obtain a plurality of CO2 concentration measurements, the sampling occurring at successive points in time in an exhalation phase and including points occurring in the plateau stage of a suitable exhalation phase;
sampling the respiratory gases of the subject during the exhalation phase at at least one point in time having a predetermined temporal relationship to the concluding portion of the plateau stage to obtain at least one alcohol concentration measurement;
comparing a CO2 concentration measurement obtained from the respiratory gases to a predetermined CO2 concentration threshold value to determine whether the CO2 concentration measurement is greater or less than the predetermined CO2 concentration value;
detecting from the measurements of CO2 concentration obtained from the sampling at successive points in time, the existence of a plateau stage in the exhalation phase being sampled;
if the existence of a plateau stage is detected and if the CO2 concentration measurement exceeds the predetermined threshold value, producing, as reliable, a blood alcohol concentration value output using the at least one alcohol concentration value measurement; and
if at least one of the conditions comprising the existence of a plateau stage and the CO2 concentration measurement exceeding the predetermined threshold value is not present, providing an output differing from that produced when the conditions are present.
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Accused Products
Abstract
A method and apparatus for measuring a blood alcohol content value by means of a breath alcohol concentration as well as for securing the reliability of this measured value. The apparatus comprises: sensor elements (1) for obtaining a measured alcohol concentration value from an incoming exhalation air stream; sensor elements (1) for obtaining a measured carbon dioxide concentration value from the same exhalation air stream (9); as well as first output elements (2) for producing, if necessary, a result proportional at least to a blood alcohol content. The apparatus further includes a first memory (M1) for storing a predetermined carbon dioxide lower threshold value or lower threshold values (R1, R2, R3 and/or Rf) and/or an upper threshold value or upper threshold values (R4, R5, R6 and/or Rg) and a first comparing element (C1) for comparing the measured carbon dioxide concentration value to said threshold values as well as a first logic element (L1) for producing outputs of a preset type depending on whether the measured carbon dioxide concentration fails to reach or exceeds the predetermined lower threshold values or upper threshold values.
57 Citations
65 Claims
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1. A method for obtaining a reliable blood alcohol concentration value from respiratory gases of a subject undergoing examination, the subject respiring gases in a respiratory cycle having an exhalation phase with exhalation stages, a respiratory cycle exhalation phase suitable for providing a reliable blood alcohol concentration value having a plateau stage, the plateau stage having a beginning and a concluding portion, respiratory gases of the subject exhaled in the plateau stage comprising alveolar gas of the subject, said method comprising the steps of:
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sampling the respiratory gases of the subject during the exhalation phase to obtain a plurality of CO2 concentration measurements, the sampling occurring at successive points in time in an exhalation phase and including points occurring in the plateau stage of a suitable exhalation phase; sampling the respiratory gases of the subject during the exhalation phase at at least one point in time having a predetermined temporal relationship to the concluding portion of the plateau stage to obtain at least one alcohol concentration measurement; comparing a CO2 concentration measurement obtained from the respiratory gases to a predetermined CO2 concentration threshold value to determine whether the CO2 concentration measurement is greater or less than the predetermined CO2 concentration value; detecting from the measurements of CO2 concentration obtained from the sampling at successive points in time, the existence of a plateau stage in the exhalation phase being sampled; if the existence of a plateau stage is detected and if the CO2 concentration measurement exceeds the predetermined threshold value, producing, as reliable, a blood alcohol concentration value output using the at least one alcohol concentration value measurement; and if at least one of the conditions comprising the existence of a plateau stage and the CO2 concentration measurement exceeding the predetermined threshold value is not present, providing an output differing from that produced when the conditions are present. - View Dependent Claims (2, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 39, 40, 41, 42, 43, 44)
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3. A method for obtaining a reliable blood alcohol concentration value from respiratory gases of a subject undergoing examination, the subject respiring gases in a respiratory cycle having an exhalation phase with exhalation stages, a respiratory cycle exhalation phase suitable for providing a reliable blood alcohol concentration value having a plateau stage, the plateau stage having a beginning and a concluding portion, respiratory gases of the subject exhaled in the plateau stage comprising alveolar gas of the subject, said method comprising the steps of:
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sampling the respiratory gases of the subject during the exhalation phase to obtain a plurality of alcohol concentration measurements, the sampling occurring at successive points in time in the plateau stage of a suitable exhalation phase and including a point having a predetermined temporal relationship to the concluding portion of the plateau stage; sampling the respiratory gases of the subject during the exhalation phase at at least one point in time to obtain a CO2 concentration measurement; comparing the CO2 concentration measurement obtained from the respiratory gases to a predetermined CO2 concentration threshold value to determine whether the CO2 concentration measurement is greater or less than the predetermined CO2 concentration value; detecting from the measurements of alcohol concentration obtained from the sampling at successive points in time, the existence of a plateau stage in the exhalation phase being sampled; if the existence of a plateau stage is detected and if the CO2 concentration measurement exceeds the predetermined threshold value, producing, as reliable, a blood alcohol concentration value output using the alcohol concentration value measurement obtained at the point having the predetermined temporal relationship to the concluding portion of the plateau stage; and if at least one of the conditions comprising the existence of a plateau stage and the Co2 concentration measurement exceeding the predetermined threshold value is not present, providing an output differing from that produced when the conditions are present. - View Dependent Claims (4)
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5. A method for obtaining a reliable blood alcohol concentration value from respiratory gases of a subject undergoing examination, the subject respiring gases in a respiratory cycle having an exhalation phase with exhalation stages, a respiratory cycle exhalation phase suitable for providing a reliable blood alcohol concentration value having a plateau stage, the plateau stage having a beginning and a concluding portion, respiratory gases of the subject exhaled in the plateau stage comprising alveolar gas of the subject, said method comprising the steps of:
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sampling the respiratory gases of the subject during the exhalation phase to obtain at least one CO2 concentration measurement; sampling the respiratory gases of the subject during the exhalation phase at at least one point in time having a predetermined temporal relationship to the concluding portion of the plateau stage to obtain an alcohol concentration measurement; comparing the CO2 concentration measurement obtained from the respiratory gases to a predetermined CO2 concentration threshold value to determine whether CO2 concentration measurement is greater or less than the predetermined CO2 concentration value; detecting from the measurement of exhaled volume or exhalation phase duration, the existence of a plateau stage in the exhalation phase being sampled; if the existence of a plateau stage is detected and if the CO2 concentration measurement exceeds the predetermined threshold value, producing, as reliable, a blood alcohol concentration value output using the alcohol concentration value measurement; and if at least one of the conditions comprising the existence of a plateau stage and the CO2 concentration measurement exceeding the predetermined threshold value is not present, providing an output differing from that produced when the conditions are present.
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24. A method for obtaining a reliable blood alcohol concentration value from respiratory gases of a subject undergoing examination, the subject respiring gases in a respiratory cycle having an exhalation phase with exhalation stages, a respiratory cycle exhalation phase suitable for providing a reliable blood alcohol concentration value having a plateau stage, the plateau stage having a beginning and a concluding portion, respiratory gases of the subject exhaled in the plateau stage comprising alveolar gas of the subject, said method comprising the steps of:
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sampling the respiratory gases of the subject during the exhalation phase to obtain a plurality of CO2 concentration measurements, the sampling occurring at successive points in time in an exhalation phase and including points occurring in the plateau stage of a suitable exhalation phase; sampling the respiratory gases of the subject during the exhalation phase at at least one point in time having a predetermined temporal relationship to the concluding portion of the plateau stage to obtain at least one alcohol concentration measurement; comparing a CO2 concentration measurement obtained from the respiratory gases to a predetermined CO2 concentration threshold value to determine whether the CO2 concentration measurement is greater or less than the predetermined CO2 concentration value; detecting from the measurements of CO2 concentration obtained from the sampling at successive points in time, the existence of a plateau stage in the exhalation phase being sampled; if the existence of a plateau stage is detected and if the CO2 concentration measurement is less than the predetermined threshold value, producing, as reliable, a blood alcohol concentration value output using the at least one alcohol concentration value measurement; and if at least one of the conditions comprising the existence of a plateau stage and the CO2 concentration measurement being less than the predetermined threshold value is not present, providing an output differing from that produced when the conditions are present. - View Dependent Claims (25, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
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26. A method for obtaining a reliable blood alcohol concentration value from respiratory gases of a subject undergoing examination, the subject respiring gases in a respiratory cycle having an exhalation phase with exhalation stages, a respiratory cycle exhalation phase suitable for providing a reliable blood alcohol concentration value having a plateau stage, the plateau stage having a beginning and a concluding portion, respiratory gases of the subject exhaled in the plateau stage comprising alveolar gas of the subject, said method comprising the steps of:
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sampling the respiratory gases of the subject during the exhalation phase to obtain a plurality of alcohol concentration measurements, the sampling occurring at successive points in time in the plateau stage of a suitable exhalation phase and including a point having a predetermined temporal relationship to the concluding portion of the plateau stage; sampling the respiratory gases of the subject during the exhalation phase at at least one point in time to obtain a CO2 concentration measurement; comparing the CO2 concentration measurement obtained from the respiratory gases to a predetermined CO2 concentration threshold value to determine whether CO2 concentration measurement is greater or less than the predetermined CO2 concentration value; detecting from the measurements of alcohol concentration obtained from the sampling at successive points in time, the existence of a plateau stage in the exhalation phase being sampled; if the existence of a plateau stage is detected and if the CO2 concentration measurement is less than the predetermined threshold value, producing, as reliable, a blood alcohol concentration value output using the alcohol concentration value measurement obtained at the point having the predetermined temporal relationship to the concluding portion of the plateau stage; and if at least one of the conditions comprising the existence of a plateau stage and the CO2 concentration measurement being less than the predetermined threshold value is not present, providing an output differing from that produced when the conditions are present. - View Dependent Claims (27)
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28. A method for obtaining a reliable blood alcohol concentration value from respiratory gases of a subject undergoing examination, the subject respiring gases in a respiratory cycle having an exhalation phase with exhalation stages, a respiratory cycle exhalation phase suitable for providing a reliable blood alcohol concentration value having a plateau stage, the plateau stage having a beginning and a concluding portion, respiratory gases of the subject exhaled in the plateau stage comprising alveolar gas of the subject, said method comprising the steps of:
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sampling the respiratory gases of the subject during the exhalation phase to obtain at least one CO2 concentration measurement; sampling the respiratory gases of the subject during the exhalation phase at at least one point in time having a predetermined temporal relationship to the concluding portion of the plateau stage to obtain an alcohol concentration measurement; comparing the CO2 concentration measurement obtained from the respiratory gases to a predetermined CO2 concentration threshold value to determine whether CO2 concentration measurement is greater or less than the predetermined CO2 concentration value; detecting from the measurement of exhaled volume or exhalation phase duration, the existence of a plateau stage in the exhalation phase being sampled; if the existence of a plateau stage is detected and if the CO2 concentration measurement is less than the predetermined threshold value, producing, as reliable, a blood alcohol concentration value output using the alcohol concentration value measurement; and if at least one of the conditions comprising the existence of a plateau stage and the CO2 concentration measurements being less than the predetermined threshold value is not present, providing an output differing from that produced when the conditions are present.
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45. Apparatus for obtaining a reliable blood alcohol concentration value from respiratory gases of a subject undergoing examination, the subject respiring gases in a respiratory cycle having an exhalation phase with exhalation stages, a respiratory cycle exhalation phase suitable for providing a reliable blood alcohol concentration value having a plateau stage, the plateau stage having a beginning and a concluding portion, respiratory gases of the subject exhaled in the plateau stage comprising alveolar gas of the subject, said apparatus comprising:
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sensor means (1) for sampling the respiratory gases of the subject during the exhalation phase, including the plateau stage of a suitable exhalation phase, to obtain CO2 concentration measurement data and alcohol concentration measurement data, said data having at least one alcohol concentration measurement obtained at a point in time having a predetermined temporal relationship to the concluding portion of the plateau stage; first memory means (M3) coupled to said sensor means for storing at least one of alcohol concentration measurement data and CO2 concentration measurement data; first comparing means (C2) coupled to said first memory means for comparing a given alcohol concentration measurement or carbon dioxide concentration measurement with an earlier measurement of the respective quantity to detect the exhalation phase plateau stage (F3) from a difference between the given and earlier concentration measurements; second memory means (M1) for storing at least one predetermined CO2 concentration threshold value; second comparing means (C1) coupled to said sensor means and said second memory means for a comparing CO2 measurement to said threshold value and producing an indicative comparison result signifying that the relationship of the CO2 concentration measurement to the threshold value is such that a respiratory gas alcohol concentration measurement is capable of accurately indicating blood alcohol concentration; and output means (2) coupled to said sensor means, said first comparing means, and said second comparing means and responsive to the detection of the existence of a plateau stage and the indicative comparison result of said second comparing element for producing, as reliable, a blood alcohol concentration value output using the at least one alcohol concentration measurement, and in the absence of at least one of the plateau stage detection and indicative comparison result, providing an output differing from that produced when such conditions are present. - View Dependent Claims (46, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65)
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47. Apparatus for obtaining a reliable blood alcohol concentration value from respiratory gases of a subject undergoing examination, the subject respiring gases in a respiratory cycle having an exhalation phase with exhalation stages, a respiratory cycle exhalation phase suitable for providing a reliable blood alcohol concentration value having a plateau stage, the plateau stage having a beginning and a concluding portion, respiratory gases of the subject exhaled in the plateau stage comprising alveolar gas of the subject, said apparatus comprising:
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sensor means (1) for sampling the respiratory gases of the subject in the exhalation phase, including the plateau stage of a suitable exhalation phase, to obtain at least one CO2 concentration measurement and at least one alcohol concentration measurement obtained at a point in time having a predetermined temporal relationship to the concluding portion of the plateau stage; measuring means for measuring at least one of the volume of exhaled respiratory gases or the duration of the exhalation phase; first memory means (M5) for storing a reference value for the quantity measured by said measuring means; first comparing means (L3) coupled to said measuring means and said first memory means for comparing the measured quantity with the reference value to detect an exhalation phase plateau stage (F3); second memory means (M1) for storing at least one predetermined CO2 concentration threshold value; second comparing means (C1) coupled to said sensor means and said second memory means for comparing a CO2 measurement to said threshold value and producing an indicative comparison result signifying that the relationship of the CO2 concentration measurement to the threshold value is such that a respiratory gas alcohol concentration measurement is capable of accurately indicating blood alcohol concentration; and output means (2) coupled to said sensor means, said first comparing means, and said second comparing means and responsive to the detection of the existence of the plateau stage and the indicative comparison result of said second comparing element for producing, as reliable, a blood alcohol concentration value output using the at least one alcohol concentration measurement, and in the absence of at least one of the plateau stage detection and indicative comparison result, providing an output differing from that produced when such conditions are present.
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Specification