KR102531358B1 - Breath alcohol analyzer - Google Patents

Abstract

The present invention relates to a breathalyzer capable of accurately measuring blood alcohol concentration even when the value of an electrical signal output from an alcohol sensor of the breathalyzer is very small. The present invention includes a sample gas chamber through which exhaled breath flows, a sensing unit disposed inside the sample gas chamber and outputting an electrical signal according to an alcohol concentration included in the exhaled breath, and a controller receiving the electrical signal from the sensing unit. A breathalyzer comprising: a first amplifier for amplifying the electrical signal by a predetermined A-fold; a second amplifying unit that amplifies the electrical signal by a predetermined B times, wherein the B value is greater than the A value; a first integration unit that obtains a first integral value (I _A ), which is an integral value over time of the electrical signal amplified by the first amplifier unit; a second integrator that obtains a second integral value I _B , which is an integral value over time of the electrical signal amplified by the second amplification unit; a comparison unit which compares the first integral value (I _A ) with a predetermined minimum threshold value (V _L ) and compares the second integral value (I _B ) with a predetermined maximum threshold value (V _H ); When the comparator determines that the second integral value (I _B ) exceeds the maximum limit value (V _H ), the alcohol concentration is calculated using the first integral value (I _A ), and the comparator When it is determined that the first integral value (I _B ) is less than the minimum limit value (V _L ), the second integral value (I _B ) A breathalyzer comprising a calculation unit for calculating the alcohol concentration to provide.

Description

Breathalyzer {Breath alcohol analyzer}

The present invention relates to a breathalyzer, and more particularly, to accurately measure the blood alcohol concentration even when the electrical signal value output from the alcohol sensor of the breathalyzer is very small, such as when the blood alcohol concentration is very low or the measurement temperature is very low. It's about a possible breathalyzer.

Breathalyzers measure the concentration of alcohol that is mixed with the air in the breath and exhaled with the breath. Since the alcohol exhaled with exhalation is proportional to the concentration of alcohol in the blood, blood alcohol concentration (BAC) can be calculated by measuring the concentration of alcohol contained in exhaled breath.

Recently, as the drinking control standards have been strengthened, even low blood alcohol concentrations are subject to enforcement. Therefore, even if the concentration of alcohol contained in exhaled breath is low, a breathalyzer that requires accurate measurement is required.

As a conventional low-concentration blood alcohol concentration measurement method, a method of changing a blood alcohol concentration conversion equation according to an electrical signal of an alcohol sensor of a breathalyzer is disclosed.

For example, in Patent Publication No. 1998-081942, experimental data are obtained for low and high blood alcohol concentrations, and based on this, a separate blood alcohol concentration conversion formula is used according to the range of data measured by the breathalyzer. A semiconductor sensor type breathalyzer is disclosed.

However, the breathalyzer disclosed in Patent Publication No. 1998-081942 has a problem in that when the concentration of alcohol contained in exhaled breath is low, the electrical signal generated from the alcohol sensor is too small, resulting in poor accuracy. That is, there is a problem in that using a separate blood alcohol concentration conversion equation according to the range of data of the electric signal of the alcohol sensor of the breathalyzer is meaningful only when the electric signal value of the alcohol sensor at a low concentration is relatively accurate.

In addition, the breathalyzer for the anti-drinking ignition prevention device installed in the vehicle must be used at a cryogenic temperature of about -40 degrees Celsius. there is a problem.

In order to solve this problem, a method of heating the alcohol sensor is used, but in the case of a cryogenic temperature, there is a problem that the user feels very uncomfortable because it takes about 2 to 3 minutes to heat.

In addition, in order to solve these problems, the amplification of the alcohol sensor signal can be increased, but if the amplification is too high, it is advantageous at low concentrations, but at high concentrations, the signal reaches the maximum measurable value, so it is difficult to measure to the maximum measurement range. .

Patent Publication No. 1998-081942 Patent Publication No. 2003-0096147 Registered Patent 10-2030278

The present invention is to improve the above-mentioned problems, and even when the concentration of alcohol contained in exhaled breath is low due to low blood alcohol concentration or when the electrical signal value output from the alcohol sensor is small, such as when measured at a cryogenic temperature, accurate It is an object of the present invention to provide a breathalyzer capable of measuring blood alcohol concentration.

In order to achieve the above object, the present invention provides a sample gas chamber through which exhaled breath flows, a sensing unit disposed inside the sample gas chamber and outputting an electrical signal according to the concentration of alcohol contained in the exhaled breath, and A breathalyzer including a controller receiving the electrical signal, the controller comprising: a first amplifying unit that amplifies the electrical signal by a predetermined A-fold; a second amplifying unit that amplifies the electrical signal by a predetermined B times, wherein the B value is greater than the A value; a first integration unit that obtains a first integral value (I _A ), which is an integral value over time of the electrical signal amplified by the first amplifier unit; a second integrator that obtains a second integral value I _B , which is an integral value over time of the electrical signal amplified by the second amplification unit; a comparison unit which compares the first integral value (I _A ) with a predetermined minimum threshold value (V _L ) and compares the second integral value (I _B ) with a predetermined maximum threshold value (V _H ); When the comparator determines that the second integral value (I _B ) exceeds the maximum limit value (V _H ), the alcohol concentration is calculated using the first integral value (I _A ), and the comparator When it is determined that the first integral value (I _B ) is less than the minimum limit value (V _L ), the second integral value (I _B ) A breathalyzer comprising a calculation unit for calculating the alcohol concentration to provide.

In addition, the controller, when the second integral value (I _B ) is less than or equal to the maximum limit value (V _H ) and the first integral value (I _A ) is greater than or equal to the minimum limit value (V _L ), the first integral value (I B ) The breathalyzer further comprises a confirmation unit for confirming the reliability of the controller by comparing two alcohol concentration values calculated using the first integral value (I _A ) and the second integral value (I _B ). to provide.

In addition, the controller amplifies the electric signal of the sensing unit by the first standard gas using the first amplifying unit and integrates using the first integrating unit to obtain a first reference value and a second standard gas. and a memory storing a second reference value obtained by amplifying an electrical signal of the sensing unit by using the second amplifier and integrating it using the second integrator, wherein the operation unit includes the first integral value (I When the alcohol concentration is calculated using _A ), the blood alcohol concentration is calculated based on the first reference value, and when the alcohol concentration is calculated using the second integral value (I _B ), based on the second reference value A breathalyzer characterized in that it calculates the blood alcohol concentration.

In addition, the breathalyzer is characterized in that the first standard gas and the second standard gas are the same gas.

In addition, the breathalyzer is characterized in that the first standard gas is a gas having a lower alcohol concentration than the second standard gas.

The breathalyzer according to the present invention has the advantage of being able to accurately measure the blood alcohol concentration even when the concentration of alcohol contained in exhaled breath is low.

In addition, it has the advantage of being able to accurately measure the blood alcohol concentration even when used at cryogenic temperatures.

1 is a conceptual diagram schematically showing a breathalyzer according to the present invention.
2 is a diagram illustrating an output signal of the sensing unit when the alcohol concentration of the sample gas is low.
3 is a diagram illustrating an output signal of the sensing unit when the alcohol concentration of the sample gas is high.
4 is a block diagram of the controller shown in FIG. 1;

Hereinafter, a preferred embodiment of a breathalyzer according to the present invention will be described in detail based on the accompanying drawings. The embodiments introduced below are provided as examples to sufficiently convey the spirit of the present invention to those skilled in the art. Therefore, the present invention may be embodied in other forms without being limited to the embodiments described below. And in the drawings, the width, length, thickness, etc. of components may be exaggerated for convenience. Like reference numbers indicate like elements throughout the specification.

1 is a conceptual diagram schematically showing a breathalyzer according to the present invention. 1, the breathalyzer according to the present invention includes an exhalation passage 2, a sample gas chamber 3 communicating with the exhalation passage 2, and a suction pump 4 connected to the sample gas chamber 3. .

The exhalation passage 2 has a cylindrical shape with both ends open. The exhalation passage (2) one end of the inlet 23 may be coupled to the buddae (1). The exhaled breath introduced into the exhalation passage 2 through the Buddha stand 1 is discharged to the outside through the outlet 24 at the other end of the exhalation passage 2.

A sampling hole 21 is formed in the exhalation passage 2 to supply a part of the exhaled breath flowing into the exhalation passage 2 to the sample gas chamber 3 . Most of the exhaled breath introduced into the exhalation passage 2 is directly discharged to the outside through the outlet 24, and a portion is supplied to the sample gas chamber 3 through the collection hole 21. Among the exhaled breath flowing through the exhalation passage 2, the exhaled breath supplied through the collection hole 21 is referred to as sample gas.

The sample gas chamber 3 is connected to the sampling hole 21 of the exhalation passage 2 through the sample gas inlet pipe 31 . A sensing unit 5 is installed inside the sample gas chamber 3 . The sensing unit 5 outputs an electrical signal that changes according to the alcohol concentration of the sample gas. An electrochemical reaction cell may be used as the sensing unit 5 .

2 is a diagram illustrating an output signal of the sensing unit when the alcohol concentration of the sample gas is low, and FIG. 3 is a diagram illustrating an output signal of the sensing unit when the alcohol concentration of the sample gas is high. For example, FIG. 2 may show an output signal when the alcohol concentration of the sample gas is 0.01 BAC%, and FIG. 3 may show an output signal when the alcohol concentration is 0.05 BAC%.

The electrochemical reaction cell includes a sensing electrode, a counter electrode, and an electrolyte interposed between the sensing electrode and the counter electrode. Alcohol adsorbed on the sensing electrode and decomposed into ions moves to the counter electrode after passing through the electrolyte.

As shown in FIGS. 2 and 3 , the value of the electrical signal generated at this time changes with time t, and the higher the alcohol concentration, the greater the maximum value of the electrical signal V.

By integrating the change graph of the electric signal value over time, a detection signal value proportional to the amount of alcohol absorbed and decomposed by the sensing electrode can be obtained, and the blood alcohol concentration can be determined using this value.

The integral value is proportional to the amount of alcohol adsorbed on the sensing electrode, the amount of alcohol adsorbed is proportional to the alcohol concentration in the sample gas, and the alcohol concentration in the sample gas is proportional to the blood alcohol concentration.

The suction pump 4 serves to introduce a fixed amount of the sample gas blown in by the user through the fire stage 1 into the sample gas chamber 3 and discharge it from the sample gas chamber 3 again. The suction pump 4 is connected to the sample gas chamber 3 through a connection pipe 34.

Since the suction pump 4 has a closed structure, gas hardly flows into the sample gas chamber 3 when the suction pump 4 does not operate.

The suction pump 4 operates instantaneously after a certain time elapses after the user starts exhaling, and introduces a fixed amount of sample gas into the sample gas chamber 3, and then immediately passes the sample gas through the sample gas inlet pipe 31. discharged from the chamber (3). Whether or not the user has started to exhale can be checked, for example, using a microphone (not shown) or a pressure sensor (not shown) installed in the exhalation passage 2 .

A solenoid pump may be used as the suction pump 4 . The solenoid pump includes a housing 41 in which a bobbin (not shown) on which an induction coil is wound is installed, and a plunger 42 installed in the hollow of the housing 41 so as to move up and down. The plunger 42 is connected to the folds 43 that can be stretched.

When power is momentarily applied to the induction coil, the plunger 42 retreats a certain distance and returns by a return spring (not shown) in the housing 41. In the process of retracting the plunger 42, the sample gas flows into the sample gas chamber 2 as the corrugated part 43 expands, and in the process of returning the plunger 42, the corrugated part 43 contracts and the sample gas enters the sample gas chamber. The sample gas in (32) is discharged through the sample gas inlet pipe (31). By limiting the movement distance of the plunger 42, a fixed amount of sample gas can be collected and a fixed amount of sample gas can be discharged. While the sample gas is introduced into and discharged from the sample gas chamber 3 , the sample gas is adsorbed to the electrochemical reaction cell of the detector 5 disposed in the sample gas chamber 3 . An electrical signal is output from the electrochemical reaction cell by the adsorbed sample gas.

The controller 6 serves to transmit a control signal for operating the suction pump 4 to the suction pump 4. In addition, the controller 6 serves to calculate the blood alcohol concentration value according to the electrical signal value received from the sensor 5 .

As shown in FIG. 4, the controller 6 includes a first amplifier 61, a second amplifier 62, a first integrator 63, a second integrator 64, and a comparison unit 65. , a memory 66, an arithmetic unit 67 and a confirmation unit 68. Although not shown, the controller 6 may further include a control signal generating unit and a control signal transmitting unit for controlling the suction pump 4 .

The first amplifying unit 61 serves to amplify the electrical signal output from the sensing unit 5 by a predetermined A-fold. Since the electrical signal output from the sensing unit 5 is very small, it is amplified and used. The first amplifier 61 may be an operational amplifier (OP-AMP). A value may be, for example, 1800.

The second amplifying unit 62 serves to amplify the electrical signal output from the sensing unit 5 by a predetermined B-fold. Like the first amplification unit 61, the second amplification unit 62 may be an operational amplifier (OP-AMP). The value of B is greater than the value of A. For example, the B value may be 6000.

The first integrator 63 serves to obtain a first integral value I _A , which is an integral value over time of the electrical signal amplified by the first amplification unit 61 .

The second integrator 64 serves to obtain a second integral value I _B , which is an integral value over time of the electrical signal amplified by the second amplification unit 62 .

Since the first integral value (I _A ) and the second integral value (I _B ) are proportional to the amount of alcohol adsorbed to the sensing electrode of the sensing unit 5 and decomposed, the blood alcohol concentration can be determined using these values.

The comparison unit 65 serves to compare the first integral value (I _A ) with a predetermined minimum limit value (V _L ) and compare the second integral value (I _B ) with a predetermined maximum limit value (V _H ). do

If the integral value exceeds the maximum limit value (V _H ), it cannot be accurately measured because the maximum value of the signal that can be processed by the controller 6 is reached. In addition, even if the integral value is less than the minimum limit value (V _L ), it is difficult to accurately measure it.

The operation unit 67 serves to calculate the alcohol concentration using the first integral value I _A and the second integral value I _B . When the comparator 65 determines that the second integral value (I _B ) exceeds the maximum limit value (V _H ), the alcohol concentration is calculated using the first integral value (I _A ). Since the fact that the second integral value (I _B ) exceeds the maximum limit value (V _H ) indicates that the alcohol concentration of the sample gas is high, the first integral value obtained without greatly amplifying the electrical signal of the sensor 5 Even using (I _A ), the alcohol concentration can be accurately calculated.

And, when the comparator 65 determines that the first integral value (I _A ) is less than the minimum limit value (V _L ), the alcohol concentration is calculated using the second integral value (I _B ). Since the fact that the first integral value (I _A ) is less than the minimum limit value (V _L ) indicates that the alcohol concentration of the sample gas is very low, the second integral value ( I _B ) must be used to accurately calculate the alcohol concentration.

The calculation unit 67 calculates the blood alcohol concentration based on the first reference value when calculating the alcohol concentration using the first integral value I _A . When the alcohol concentration is calculated using the second integral value I _B , the blood alcohol concentration is calculated based on the second reference value.

The first reference value and the second reference value are reference values obtained in a calibration process of the manufactured breathalyzer. The first reference value is obtained by amplifying the electrical signal of the sensing unit 5 by the first standard gas using the first amplifying unit 61 and integrating using the first integrating unit 63 ( 6) is the intrinsic calibration value. The first standard gas may be a standard gas having a high alcohol concentration. For example, the first standard gas may be a standard gas corresponding to 0.05 BAC% (blood-alcohol concentration %).

The second reference value is obtained by amplifying the electrical signal of the sensing unit 5 by the second standard gas using the second amplifying unit 62 and integrating using the second integrating unit 64. 6) is the intrinsic calibration value. The second standard gas may be a standard gas having a low alcohol concentration. For example, the second standard gas may be a standard gas corresponding to 0.01 BAC%.

In addition, the same gas may be used as the first standard gas and the second standard gas. One suitable concentration, so that valid signals are obtained for both amplifications. For example, a gas corresponding to 0.03 BAC% may be used as the first standard gas and the second standard gas.

The first reference value and the second reference value are stored in the memory 66 . The memory 66 may be, for example, a non-volatile memory such as Electrically Erasable Programmable Read-Only Memory (EEPROM).

The calculation unit 67 calculates the blood alcohol concentration by comparing the value obtained by integrating the electric signal value received from the sensor 5 over time with the first reference value or the second reference value stored in the memory 64 .

When the alcohol concentration is calculated using the first integral value (I _A ), the blood alcohol concentration is calculated based on the first reference value, and when the alcohol concentration is calculated using the second integral value (I _B ), the second reference value Calculate blood alcohol concentration based on

For example, when the first reference value obtained by using the first standard gas corresponding to 0.05BAC% is a and the first integral value (I _A ) is 0.5a, the blood alcohol concentration is 0.5×0.05BAC% It can be calculated as 0.025 BAC% of phosphorus.

In the same way, when the second reference value obtained by using the second standard gas corresponding to 0.01BAC% is b and the second integral value (I _B ) is 0.5b, the blood alcohol concentration is 0.5×0.01BAC% It can be calculated as 0.005 BAC% of phosphorus.

The blood alcohol concentration value calculated by the calculation unit 67 is displayed on the display unit 7 .

The confirmation unit 68 serves to confirm the reliability of the controller 6.

The confirmation unit 68 determines that the blood alcohol concentration is not very high or low, so that the second integral value (I _B ) is less than or equal to the maximum limit value (V _H ), and the first integral value (I _A ) is the minimum limit value (V _L ) or more, the two alcohol concentration values calculated using the first integral value (I _A ) and the second integral value (I _B ) are compared.

And based on this, the reliability of the controller 6 is confirmed. For example, if the difference between the two alcohol concentration values is 10% or more, it can be determined that the controller 6 has a problem.

The embodiments described above are merely those of the preferred embodiments of the present invention, and the scope of the present invention is not limited to the described embodiments, and within the technical spirit and claims of the present invention, those skilled in the art Various changes, modifications or substitutions will be possible by, and it should be understood that such embodiments fall within the scope of the present invention.

1: fire stand
2: exhalation passage
3: sample gas chamber
31: sample gas inlet pipe
34: connector
4: suction pump
5: sensing unit
6: Controller
7: display

Claims (5)

Drinking comprising a sample gas chamber through which exhaled breath flows, a sensor disposed inside the sample gas chamber and outputting an electrical signal according to the concentration of alcohol contained in the exhaled breath, and a controller receiving the electrical signal from the sensor. In the meter,
The controller,
a first amplifier for amplifying the electrical signal by a predetermined A-fold;
a second amplifying unit that amplifies the electrical signal by a predetermined B times, wherein the B value is greater than the A value;
A first integration unit for obtaining a first integral value (I _A ), which is an integral value over time of the electrical signal amplified by the first amplifier unit;
a second integrator for obtaining a second integral value I _B , which is an integral value over time of the electrical signal amplified by the second amplification unit;
A comparator for comparing the first integral value (I _A ) with a predetermined minimum limit value (V _L ) and comparing the second integral value (I _B ) with a predetermined maximum limit value (V _H );
When the comparator determines that the second integral value (I _B ) exceeds the maximum limit value (V _H ), the alcohol concentration is calculated using the first integral value (I _A ), and the comparator And a calculation unit for calculating the alcohol concentration using the second integral value (I _B ) when it is determined that the first integral value (I _B ) is less than the minimum limit value (V _L ) Breathalyzer. According to claim 1,
The controller,
When the second integral value I _B is less than or equal to the maximum limit value V _H and the first integral value I _A is greater than or equal to the minimum limit value V _L , the first integral value I _A ) and the second integral value (I _B ) by comparing the two alcohol concentration values calculated respectively using the second integral value (I B ) to check the reliability of the controller further comprising a checker. According to claim 1,
The controller,
A first reference value obtained by amplifying the electric signal of the sensing unit by the first standard gas by using the first amplifying unit and integrating the electrical signal of the sensing unit by using the first integrating unit, and the electrical signal of the sensing unit by the second standard gas A memory storing a second reference value obtained by amplifying by using the second amplifier and integrating by using the second integrating unit;
The calculation unit,
When the alcohol concentration is calculated using the first integral value (I _A ), the blood alcohol concentration is calculated based on the first reference value, and when the alcohol concentration is calculated using the second integral value (I _B ), the A breathalyzer that calculates the blood alcohol concentration based on the second reference value. According to claim 3,
Breathalyzer, characterized in that the first standard gas and the second standard gas are the same gas. According to claim 3,
Breathalyzer, characterized in that the first standard gas is a gas having a higher alcohol concentration than the second standard gas.

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