A method for calculating drinking time includes: drawing a plurality of blood samples within 0 to 120 h upon start of drinking, testing concentrations of alcohol, EtG and EtS in the blood samples, and obtaining an average concentration ratio C.sub.EtG/C.sub.EtS; obtaining a quadratic regression equation by fitting using the average concentration ratio C.sub.EtG/C.sub.EtS as an abscissa and sampling time as an ordinate; and measuring C.sub.EtG/C.sub.EtS of blood samples under test, obtaining a relationship between the drinking time and the C.sub.EtG/C.sub.EtS based on the quadratic regression equation, and calculating the drinking time.

A method for calculating drinking time includes: drawing a plurality of blood samples within 0 to 120 h upon start of drinking, testing concentrations of alcohol, EtG and EtS in the blood samples, and obtaining an average concentration ratio C.sub.EtG/C.sub.EtS; obtaining a quadratic regression equation by fitting using the average concentration ratio C.sub.EtG/C.sub.EtS as an abscissa and sampling time as an ordinate; and measuring C.sub.EtG/C.sub.EtS of blood samples under test, obtaining a relationship between the drinking time and the C.sub.EtG/C.sub.EtS based on the quadratic regression equation, and calculating the drinking time.

A method and system for monitoring a user's intoxication including receiving a set of signals, derived from a set of samples collected from the user at a set of time points; providing a sobriety task to the user proximal to a time point of the set of time points; generating a performance dataset characterizing performance of the sobriety task by the user; receiving a supplementary dataset characterizing a demographic profile of the user and/or a physiological state of the user; determining a set of values of an intoxication metric, derived from the set of signals; generating a predicted temporal profile of the intoxication metric for the user based upon the set of values, the set of time points, and the supplementary dataset; generating an analysis of the user's sobriety based upon the performance dataset and the predicted temporal profile; and providing a notification to the user based upon the analysis.

A method and system for monitoring a user's intoxication including receiving a set of signals, derived from a set of samples collected from the user at a set of time points; providing a sobriety task to the user proximal to a time point of the set of time points; generating a performance dataset characterizing performance of the sobriety task by the user; receiving a supplementary dataset characterizing a demographic profile of the user and/or a physiological state of the user; determining a set of values of an intoxication metric, derived from the set of signals; generating a predicted temporal profile of the intoxication metric for the user based upon the set of values, the set of time points, and the supplementary dataset; generating an analysis of the user's sobriety based upon the performance dataset and the predicted temporal profile; and providing a notification to the user based upon the analysis.

A method and system for monitoring a user's intoxication including receiving a set of signals, derived from a set of samples collected from the user at a set of time points; providing a sobriety task to the user proximal to a time point of the set of time points; generating a performance dataset characterizing performance of the sobriety task by the user; receiving a supplementary dataset characterizing a demographic profile of the user and/or a physiological state of the user; determining a set of values of an intoxication metric, derived from the set of signals; generating a predicted temporal profile of the intoxication metric for the user based upon the set of values, the set of time points, and the supplementary dataset; generating an analysis of the user's sobriety based upon the performance dataset and the predicted temporal profile; and providing a notification to the user based upon the analysis.

A method and system for monitoring a user's intoxication including receiving a set of signals, derived from a set of samples collected from the user at a set of time points; providing a sobriety task to the user proximal to a time point of the set of time points; generating a performance dataset characterizing performance of the sobriety task by the user; receiving a supplementary dataset characterizing a demographic profile of the user and/or a physiological state of the user; determining a set of values of an intoxication metric, derived from the set of signals; generating a predicted temporal profile of the intoxication metric for the user based upon the set of values, the set of time points, and the supplementary dataset; generating an analysis of the user's sobriety based upon the performance dataset and the predicted temporal profile; and providing a notification to the user based upon the analysis.

An apparatus for controlling alcohol interlock includes a sensor that senses an environment of a driver's seat and a camera that obtains a face image of a passenger and an image of exhalation of the passenger. A controller activates a start lock mode of a vehicle and determines whether a condition for detecting components of the exhalation of the passenger is satisfied based on the environment of the driver's seat. The controller determines whether the exhalation of the passenger is exhalation of a driver based on the face image of the passenger and the image of the exhalation of the passenger, and determines whether to detect alcohol concentration in the exhalation of the passenger based on the determination result.

An apparatus for controlling alcohol interlock includes a sensor that senses an environment of a driver's seat and a camera that obtains a face image of a passenger and an image of exhalation of the passenger. A controller activates a start lock mode of a vehicle and determines whether a condition for detecting components of the exhalation of the passenger is satisfied based on the environment of the driver's seat. The controller determines whether the exhalation of the passenger is exhalation of a driver based on the face image of the passenger and the image of the exhalation of the passenger, and determines whether to detect alcohol concentration in the exhalation of the passenger based on the determination result.

The disclosed technology includes device, systems, and methods for detecting an analyte using a biosensor. In some implementations, the biosensor may be a transdermal biosensor including a housing material, a nanocellulose material disposed within the housing material, an enzyme entrapped within the nanocellulose material that produces a chemical or biological product when exposed to a vapor or liquid, and a luminescent material within the nanocellulose material that emits visible light upon a chemical or biological reaction with the chemical or biological product.

The present invention relates to a method and apparatus for measuring breath alcohol concentration of a user. A flow of an expired breath sample is passed through a fuel cell sensor giving an output signal proportional to the amount of alcohol present in the breath sample. By measuring the flow rate, the volume of the breath sample may be calculated, whereas the breath alcohol concentration is calculated based on the fuel cell output signal. Both the sample volume and the breath alcohol concentration values are continually updated by integrating the measured instantaneous flow rate and the fuel cell output signal over time. If the user stops blowing, flow compensation is performed to obtain a compensated fuel cell output signal using a stored calibration volume. Hence, an improved method for accurately measuring the breath alcohol concentration of a test person is achieved, capable of handling varied expired volumes of breath, which obviates the need for a sampling mechanism.