DE102023202193A1 - Evaluation device, system and method for checking the plausibility of an exhalation sample from a vehicle user - Google Patents

Abstract

Evaluation device for checking the plausibility of an exhaled breath sample from a vehicle user, the evaluation device comprising:
• a first interface to a first sensor for detecting at least one marker substance in the exhaled breath sample of the vehicle user, wherein the evaluation device receives first sensor data about the marker substance via the first interface;
• at least one second interface to at least one second sensor, wherein the second sensor records current properties of the exhaled breath sample comprising air humidity or components of the exhaled breath sample comprising the O ₂ concentration as second sensor data and the evaluation device receives the second sensor data via the second interface;
• wherein the evaluation device checks the plausibility of the first sensor data based on the second sensor data by logically linking the first sensor data and the second sensor data.

Description

The invention relates to an evaluation device and a system for checking the plausibility of an exhalation sample from a vehicle user. The invention also relates to methods for checking the plausibility of an exhalation sample from a vehicle user.

The following definitions apply to the entire disclosure content.

Evaluation devices and methods are already known from the state of the art that measure the _CO2 concentration of an exhaled breath sample to verify its plausibility.

The object of the invention was to provide an improved evaluation device for checking the plausibility of an exhaled breath sample from a vehicle user.

The subject matters of the independent claim and the subordinate claims each solve this problem.

• • eine erste Schnittstelle zu einem ersten Sensor zum Nachweis mindestens einer Markersubstanz in der Ausatemprobe des Fahrzeugnutzers, wobei die Auswerteeinrichtung über die erste Schnittstelle erste Sensordaten über die Markersubstanz erhält;
• • mindestens eine zweite Schnittstelle zu mindestens einem zweiten Sensor, wobei der zweite Sensor momentane Eigenschaften der Ausatemprobe umfassend Luftfeuchtigkeit oder Bestandteile der Ausatemprobe umfassend die O₂-Konzentration als zweite Sensordaten erfasst und die Auswerteeinrichtung über die zweite Schnittstelle die zweiten Sensordaten erhält;
• • wobei die Auswerteeinrichtung durch logische Verknüpfung der ersten Sensordaten und der zweiten Sensordaten die ersten Sensordaten basierend auf den zweiten Sensordaten plausibilisiert.

According to one aspect, the invention provides an evaluation device for checking the plausibility of an exhaled breath sample of a vehicle user, the evaluation device comprising:

• • a first interface to a first sensor for detecting at least one marker substance in the exhaled breath sample of the vehicle user, wherein the evaluation device receives first sensor data about the marker substance via the first interface;
• • at least one second interface to at least one second sensor, wherein the second sensor records current properties of the exhaled breath sample comprising air humidity or components of the exhaled breath sample comprising the O ₂ concentration as second sensor data and the evaluation device receives the second sensor data via the second interface;
• • wherein the evaluation device checks the plausibility of the first sensor data based on the second sensor data by logically linking the first sensor data and the second sensor data.

The exhaled breath sample, which is checked for plausibility by the evaluation device, comes from a vehicle user. A vehicle user can, for example, be a vehicle occupant in the case of a passenger vehicle. A vehicle user can also be a user of an e-scooter, for example. The exhaled breath sample is mixed with the ambient air.

The plausibility check determines whether the exhaled breath sample is a human breath sample or whether it is a fictitious breath sample.

The evaluation unit receives sensor data about at least one marker substance via the first interface. It is also possible for the sensor to detect several marker substances and transmit them to the evaluation unit. The at least one marker substance can be a variety of substances, for example to determine the vehicle user's ability to drive, for example due to alcohol consumption and/or drug consumption and/or tiredness. To detect alcohol consumption, the marker substance can be ethanol. To detect drug consumption, the marker substance can be a breakdown product of tetrahydrocannabinol. To detect tiredness, the marker substance can be isoprene. The detection of certain marker substances can also be used, for example, to detect diseases.

The evaluation device receives second sensor data via at least the second interface. The current properties and/or the components of the exhaled breath sample characterize a state of the physical system of the exhaled breath sample. The state is characterized, for example, by the O ₂ concentration, since the O ₂ concentration is a characteristic plausibility value for an exhaled breath sample and this cannot be faked with little effort.

The evaluation device checks the plausibility of the first sensor data based on the second sensor data by logically linking the first sensor data and the second sensor data. This makes it possible to determine whether the exhalation sample comes from a human vehicle user or whether the exhalation sample was possibly faked. As expected, the O ₂ concentration of a human exhalation sample is 1 to 5%, preferably 4 to 5%, lower than the O ₂ concentration in the ambient air.

The humidity of an exhaled breath sample is expected to be 100% relative humidity.

The result of the evaluation device can then be forwarded, for example, to an alcohol interlock system, called an alcolock for short, in the vehicle. An alcolock is an immobilizer that includes locking options and/or actuators that can restrict or prevent the vehicle from starting and/or continuing to drive. Examples of such immobilizers are ignition locks, mechanical and/or electronic handbrakes, brakes, gearbox lock, eMotor lock. In one aspect, the immobilizer is an electronic immobilizer.

The evaluation device can, for example, be integrated into a vehicle. A vehicle can, for example, be a passenger vehicle, commercial vehicle, e-scooter, e-bike, motorcycle or a construction machine such as an excavator or a tractor.

• • eine Auswerteeinrichtung;
• • einen ersten Sensor, wobei der erste Sensor mittels einer ersten Schnittstelle mit der Auswerteeinheit verbunden ist;
• • mindestens einen zweiten Sensor, wobei der mindestens zweite Sensor mittels einer mindestens zweiten Schnittstelle mit der Auswerteeinheit verbunden ist;
• • wobei das System durch logische Verknüpfung der ersten Sensordaten und der weiteren Sensordaten die ersten Sensordaten basierend auf den weiteren Sensordaten plausibiliert.

According to a further aspect, the invention provides a system for checking the plausibility of an exhaled breath sample of a vehicle user, the system comprising:

• • an evaluation device;
• • a first sensor, wherein the first sensor is connected to the evaluation unit by means of a first interface;
• • at least one second sensor, wherein the at least second sensor is connected to the evaluation unit by means of at least one second interface;
• • whereby the system checks the plausibility of the first sensor data based on the further sensor data by logically linking the first sensor data and the further sensor data.

The first sensor can, for example, be a sensor that works on the principle of infrared spectroscopy. The sensor can be connected to the evaluation unit wirelessly, for example via radio, in particular WLAN, or Bluetooth, or by wire.

The second sensor can, for example, be an electrochemical or ultrasound-based sensor to measure the O2 concentration.

If other state variables are considered for plausibility, the second sensor can also be a piezo-resistive sensor, for example for measuring air pressure. However, it can also be a bi-metal thermocouple or a resistance temperature sensor, for example for measuring temperature.

The second sensor can also be connected to the evaluation unit wirelessly, for example via radio, in particular WLAN, or Bluetooth, or by wire. However, other first and/or second sensors are also possible.

By logically linking the first sensor data and the second sensor data, the system checks the plausibility of the first sensor data based on the second sensor data in order to detect possible manipulation of exhaled breath samples by the system.

The system can, for example, be integrated into a vehicle. A vehicle can, for example, be a passenger vehicle, commercial vehicle, e-scooter, e-bike, motorcycle or a construction machine such as an excavator or a tractor.

• • Erfassung von ersten Sensordaten zum Nachweis einer Markersubstanz in der Ausatemprobe des Fahrzeugnutzers;
• • Erfassung von mindestens zweiten Sensordaten zum Bestimmen eines Zustandes der Ausatemprobe, wobei der Zustand Eigenschaften und/oder Bestandteile der Ausatemprobe kennzeichnet;
• • Plausibilisierung der ersten Sensordaten mittels der weiteren Sensordaten durch logische Verknüpfung der ersten und der weiteren Sensordaten.

According to a further aspect, the invention provides a method for checking the plausibility of an exhaled breath sample of a vehicle user, the method comprising the following steps:

• • Collection of initial sensor data to detect a marker substance in the vehicle user’s exhaled breath sample;
• • Acquiring at least second sensor data to determine a state of the exhaled breath sample, the state characterizing properties and/or components of the exhaled breath sample;
• • Plausibility check of the first sensor data using the additional sensor data by logically linking the first and additional sensor data.

The step of collecting initial sensor data to detect a marker substance in the vehicle user's exhaled breath sample includes the detection of a marker substance and the transmission of the detected data to an evaluation unit.

The step of collecting the second sensor data to determine a state of the exhaled breath sample includes the detection of a state and the transmission of the detected data to the evaluation unit.

Because the method checks the plausibility of the first sensor data based on the second sensor data by logically linking the first sensor data and the second sensor data, possible manipulation of exhaled breath samples can be detected without a supervisor having to monitor the process. The logical link can be an if/else control structure, for example. The plausibility check can also be carried out using artificial intelligence. For example, a machine learning model, such as an artificial neural network or another data-driven model or a combination of these can be trained and/or linked to detect real and fictitious breaths.

For example, the O ₂ concentration can be used as a state variable to check plausibility. As expected, the O ₂ concentration of a human exhaled breath sample is, as already described above, 1 to 5%, preferably 4 to 5%, lower than the O ₂ concentration in the ambient air.

According to a further aspect, the invention provides for the use of an evaluation device in a vehicle, wherein the evaluation device is integrated into the vehicle and the vehicle is a passenger vehicle, commercial vehicle, e-scooter, e-bike, motorcycle or construction machine.

In a passenger vehicle, for example, the evaluation device can be integrated into the on-board network.

Further developments and advantageous embodiments emerge from the subclaims, the drawings and the description of preferred embodiments.

According to one aspect, the invention provides an evaluation device, wherein the second sensor detects current properties of the exhaled breath sample, including air humidity, and components of the exhaled breath sample, including the O ₂ concentration. Other components of the exhaled breath sample can be, for example, volatile organic compounds, such as carbon monoxide, acetone, isoprene, ammonia, 2-pentanone, 2-butanone, acetaldehyde.

According to a further aspect, the invention provides an evaluation device, wherein the second sensor detects current properties of the exhaled breath sample comprising air temperature and/or air pressure and/or exhaled breath flow.

By recording the air temperature and/or the air pressure and/or the exhalation flow, it is also possible to obtain information as to whether the exhalation sample is real or fictitious. All of these variables are characteristic of an exhalation sample. The exhalation flow is typically measured in l/s.

Air pressure here is understood to be a dynamic pressure that is measured at the sensor inlet, for example via a piezo-resistive differential pressure sensor, and from which the flow velocity of the exhaled breath sample and thus, with a known inlet cross-section, the supplied exhaled breath flow in l/s can be determined.

An exhaled breath sample is expected to have an air temperature of about 34 °C.

According to a further aspect, the invention provides an evaluation device, wherein the second sensor detects components of the exhaled breath sample comprising the CO ₂ concentration.

The _CO2 concentration of an exhaled breath sample is expected to be about 4%.

According to a further aspect, the invention provides an evaluation device, wherein the at least one marker substance is a volatile organic compound. Human exhaled air contains several hundred volatile organic compounds, also called Volatile Organic Compounds (VOCs), the concentration of which reflects normal and pathological metabolic processes and physiological processes in the body.

Examples of such organic compounds are ethanol, tetrahydrocannabinol and isoprene. As described above, alcohol consumption can be detected through ethanol, drug consumption through tetrahydrocannabinol and its breakdown products, and fatigue through isoprene.

According to a further aspect, the invention provides an evaluation device, wherein the at least one marker substance is ethanol.

In order to obtain an indication of alcohol consumption by a vehicle user, especially the driver, the detection of ethanol plays an important role.

According to a further aspect, the invention provides an evaluation device, wherein the second sensor data comprise an amplitude level and/or a variance and/or at least one gradient and/or a maximum deviation from at least one expected nominal value and/or at least one time of a rise and/or fall and/or a ratio of at least two state variables of the exhaled breath sample.

The second sensor data plays an important role in the plausibility of the exhalation sample. The amplitude level includes information on the signal values of the sensors, for example a concentration. In relation to the O ₂ concentration, the amplitude level can, for example, relate to the oscillation width of the second sensor data: With periodic inhalation and exhalation, the O ₂ concentration measured with the second sensor shows a periodic course; with inhalation there is an increase to 21% and with exhalation there is a decrease to 16%. The amplitude level here is approximately 5% in each case. The variance is an average deviation from the amplitude level within this time interval.

The gradient can, for example, provide information about the temporal change of the amplitude height.

The maximum deviation from at least one expected nominal value may, for example, reflect the maximum permissible deviation of the O ₂ concentration in order to evaluate an exhaled breath sample as non-fictitious.

The time course of an exhaled breath sample shows, for example, a point in time where the CO ₂ concentration increases and decreases. It can also be a time period within which the value, for example the CO ₂ concentration, increases and/or decreases. Between these points in time or time periods, the expected course of the CO ₂ concentration is almost constant. This time interval can be referred to as the evaluation range.

It was found that the ratio of at least two state variables of the exhaled breath sample can also provide important information for the plausibility of the exhaled breath sample.

In a further embodiment of the method, an evaluation device according to the invention or a system according to the invention is used to carry out the method.

• 1 ein Beispiel eines Ausatemzyklus-Diagrammes,
• 2 ein Beispiel eines Atemprofils einer Ausatemprobe,
• 3 ein Flussdiagramm eines erfindungsgemäßen Verfahrens.

The invention is explained by way of example using the following embodiments. They show:

• 1 an example of an exhalation cycle diagram,
• 2 an example of a breathing profile of an exhaled breath sample,
• 3 a flow chart of a method according to the invention.

In the figures, identical reference symbols refer to identical or functionally similar objects. In order to avoid repetition, only the relevant objects are identified by reference symbols in the figures.

The 1 The example of an exhalation cycle diagram shown shows the amplitude level 100 on the y-axis of first and several second sensor data, here as an example the CO ₂ - 103 and ethanol characteristics 102 in the temporal course 101 (x-axis) of an exhalation cycle. The 1 The time 1 T1 shown represents an example of a time at which a threshold value of the increase in the CO ₂ concentration is reached. The increase lasts until the time 3 T3. The interval between the times 1 T1 and 3 T3 represents a rise region 104. After the rise region 104, the amplitude level is relatively constant. This time interval is referred to as the evaluation region 105. During this time interval, for example, the 1 The ethanol concentration shown (amplitude level 100) is determined by means of a first sensor and the CO ₂ concentration (amplitude level 100) is determined by means of a second sensor and transmitted to an evaluation unit according to the invention. After this time interval, the amplitude level 100 drops again. The time 2 T2 shown represents the time at which the amplitude level 100, i.e. the CO ₂ concentration, has reached the same threshold value as during the increase at time 1 T1. According to the 1 In the diagram shown, time 1 T1 represents the time of increase and time 4 T4 represents the time of decrease. The 1 The area shown between times T4 and T2 is the decay area 106. In this area the concentration decreases again.

The 2 The example shown of a breathing profile of an exhaled breath sample shows the temporal course 101 of different measured values. 2 shows a clear change in the amplitude level 100 in the course of the CO ₂ characteristic curve 103. This curve is an example of a non-simulated exhalation sample. The course of the 2 In contrast to the CO ₂ characteristic curve 103, the ethanol characteristic curve 102, H ₂ O characteristic curve 107 and ethanol + H ₂ O characteristic curve 108 shown show hardly any change in the amplitude level 100 over time 101.

The 3 The flow chart of a method according to the invention shown comprises a step 200 of recording first sensor data for detecting a marker substance in the exhaled breath sample of the vehicle user. Furthermore, the method comprises a step 201 of recording second sensor data for determining a state of the exhaled breath sample and a step 202 of checking the plausibility of the first sensor data using the second sensor data by logically linking the first and second sensor data.

Reference symbols

100

Amplitude height

101

Timeline

102

Ethanol characteristic curve

103

CO2 characteristic curve

104

Rise range

105

Evaluation area

106

Waste area

107

H2O characteristic curve

108

Ethanol + H2O characteristic curve

T1

Time 1

T2

Time 2

T3

Time 3

T4

Time 4

200-202

Process steps

Claims (11)

Evaluation device for checking the plausibility of an exhalation sample from a vehicle user, the evaluation device comprising: • a first interface to a first sensor for detecting at least one marker substance in the exhalation sample from the vehicle user, wherein the evaluation device receives first sensor data about the marker substance via the first interface; • at least one second interface to at least one second sensor, wherein the second sensor records current properties of the exhalation sample comprising air humidity or components of the exhalation sample comprising the O ₂ concentration as second sensor data and the evaluation device receives the second sensor data via the second interface; • wherein the evaluation device checks the plausibility of the first sensor data based on the second sensor data by logically linking the first sensor data and the second sensor data. Evaluation device according to Claim 1 , wherein the second sensor detects instantaneous properties of the exhaled breath sample including humidity and components of the exhaled breath sample including O ₂ concentration. Evaluation device according to Claim 1 or 2 , wherein the second sensor detects instantaneous properties of the exhaled breath sample comprising air temperature and/or air pressure and/or exhaled breath flow. Evaluation device according to Claim 1 or 2 , wherein the second sensor detects components of the exhaled breath sample including the CO ₂ concentration. Evaluation device according to one of the preceding claims, wherein the at least one marker substance is a volatile organic compound. Evaluation device according to one of the preceding claims, wherein the at least one marker substance is ethanol. Evaluation device according to one of the preceding claims, wherein the second sensor data comprise an amplitude level (100) and/or a variance and/or at least one gradient and/or a maximum deviation from at least one expected nominal value and/or at least one time of a rise and/or fall and/or a ratio of at least two state variables of the exhaled breath sample. System for checking the plausibility of an exhaled breath sample from a vehicle user, the system comprising: • an evaluation device according to one of the preceding claims; • a first sensor, wherein the first sensor is connected to the evaluation unit by means of a first interface; • at least one second sensor, wherein the at least second sensor is connected to the evaluation unit by means of at least a second interface; • wherein the system checks the plausibility of the first sensor data based on the further sensor data by logically linking the first sensor data and the further sensor data. Method for checking the plausibility of an exhalation sample of a vehicle user, the method comprising the following steps: • Acquisition of first sensor data for detecting a marker substance in the exhalation sample of the vehicle user (200); • Acquisition of at least second sensor data for determining a state of the exhalation sample (201), wherein the state characterizes properties and/or components of the exhalation sample; • Checking the plausibility of the first sensor data using the further sensor data by logically linking the first and the further sensor data (202). Procedure according to Claim 9 , whereby to carry out the method an evaluation device according to Claim 1 until 7 or a system according to Claim 8 is used. Use of an evaluation device according to Claim 1 until 7 in a vehicle, whereby the evaluation device is integrated into the vehicle and the vehicle is a passenger vehicle, commercial vehicle, e-scooter, e-bike, motorcycle or construction machine.

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