JP2010281698A - Skin gas detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect accurately a concentration of a detection object material in blood from skin gas. <P>SOLUTION: A base value and a saturated value of a concentration of ethanol gas is obtained based on a detection signal from an alcohol sensor 24A by a first sensor output acquisition part 32. A base value and a saturated value of a concentration of carbon dioxide is obtained based on a detection signal from a carbon dioxide sensor 24B by a second sensor output acquisition part 34. The ethanol concentration in blood is calculated based on a variation of the concentration of ethanol gas and a variation of the concentration of carbon dioxide by an in-blood concentration calculation part 36, and displayed on a display 40. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a skin gas detection device, and more particularly to a skin gas detection device that detects gas diffused from the skin of a detection target person and detects the concentration of a detection target substance in blood.

  Conventionally, a detection device that estimates a specific substance in blood from skin gas concentration is known. For example, a skin permeation gas measuring device having a container that stores skin gas permeating gas and has an opening, a blower fan that circulates the skin permeating gas, and a gas measuring device in a gas circulation path is known (Patent Document 1). . In this Patent Document 1, a method of collecting and storing gas that permeates from the skin and quantifying the concentration by gas chromatography or the like is shown, and it is shown that the blood concentration correlates with the skin gas concentration.

JP 2006-234845 A

  However, in the technique described in Patent Document 1 described above, in the diffusion from the blood to the skin tissue, there is a great influence by individual differences and the environment (such as a change in subcutaneous temperature due to the air temperature). Cannot be detected accurately.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a skin gas detection device that can accurately detect the concentration of a detection target substance in blood from skin gas.

  In order to achieve the above object, a skin gas detection device of the present invention comprises a target gas detection means for detecting the concentration of a detection target gas in which a detection target substance in the blood of the detection target diffuses as a gas from the skin, Reference gas detection means for detecting the concentration of a reference gas having a stable concentration and water solubility and diffused from the skin, the concentration of the detection target gas detected by the target gas detection means, and the reference Blood concentration calculation means for calculating the concentration of the detection target substance in the blood based on the concentration of the reference gas detected by the gas detection means.

  According to the skin gas detection device of the present invention, the target gas detection means detects the concentration of the detection target gas in which the detection target substance in the blood of the detection target diffuses as gas from the skin. Further, the reference gas detection means detects the concentration of the reference gas that has a stable blood concentration and is water-soluble and diffuses from the skin.

  Then, the concentration of the detection target substance in the blood is calculated by the blood concentration calculation means based on the concentration of the detection target gas detected by the target gas detection means and the concentration of the reference gas detected by the reference gas detection means. To do.

  Thus, by detecting the concentration of the detection target gas diffused from the skin and the concentration of the reference gas, the concentration of the detection target substance in the blood can be accurately detected from the skin gas.

  The diffusion coefficient indicating the degree of diffusion of the reference gas of the present invention from the blood into the skin is correlated with the diffusion coefficient of the detection target substance. As a result, the influence of changes in the diffusion coefficient can be reduced, and the concentration of the detection target substance in the blood can be detected with high accuracy.

  The skin gas detection device according to the present invention further includes a housing having a placement portion for placing a predetermined part of the detection target person and a storage chamber for storing gas diffused from the skin of the predetermined part. The gas detection means can detect the concentration of the detection target gas in the storage chamber, and the reference gas detection means can detect the concentration of the reference gas in the storage chamber.

  The blood concentration calculation means according to the present invention can calculate the concentration of the detection target substance in the blood according to the following equation.

  Concentration of detection target substance in blood = a × (ΔGas) / (ΔRef)

  However, ΔGas is the amount of change in the concentration of the detection target gas detected by the target gas detection means, ΔRef is the amount of change in the concentration of the reference gas detected by the reference gas detection means, and a is a coefficient.

  The substance to be detected can be either ethanol or acetone.

  As described above, according to the present invention, the concentration of the detection target substance in the blood can be accurately detected from the skin gas by detecting the concentration of the detection target gas diffused from the skin and the concentration of the reference gas. The effect of being able to be obtained is obtained.

It is a perspective view which shows the structure of the ethanol concentration detection apparatus of the 1st Embodiment of this invention. It is the schematic which shows the structure of the ethanol concentration detection apparatus of the 1st Embodiment of this invention. (A) The graph which shows the change of the sensor output of an alcohol sensor, (B) The graph which shows the change of the sensor output of a carbon dioxide sensor. It is a block diagram which shows the structure of the ethanol concentration detection apparatus of the 1st Embodiment of this invention. It is an image figure which shows a mode that it diffuses from the skin through the subcutaneous tissue from the skin to the exterior. It is a graph which shows the relationship between a skin gas measured value and blood concentration. It is a flowchart which shows the content of the ethanol concentration detection processing routine in the computer of the ethanol concentration detection apparatus of the 1st Embodiment of this invention. It is the schematic which shows the structure of the ethanol concentration detection apparatus of the 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, an ethanol concentration detection device that detects the gas diffused from the skin of the palm of the detection subject and detects the blood concentration of ethanol, which is a kind of alcohol as the detection target substance, A case where the present invention is applied will be described as an example.

  As shown in FIGS. 1 and 2, the ethanol concentration detection device 10 according to the first embodiment includes a housing 12 that is open at the center of the upper surface, and the housing 12 is opened by the opening. A storage chamber 14 for storing gas is formed in the recess. The peripheral portion of the opening of the housing 12 is used as a placement portion for placing the palm of the person to be detected.

  A sensor group 24 is attached to the bottom of the storage chamber 14 of the housing 12. The sensor group 24 includes an alcohol sensor 24A and a carbon dioxide sensor 24B attached so as to detect the gas in the storage chamber 14.

  The alcohol sensor 24A is a sensor that detects ethanol gas contained in the gas in the storage chamber 14, and has high sensitivity to ethanol gas. For example, an electrochemical alcohol sensor can be used as the alcohol sensor 24A.

  The carbon dioxide sensor 24B is a sensor that detects carbon dioxide contained in the gas in the storage chamber 14, and has sensitivity to carbon dioxide. As the carbon dioxide sensor 24B, for example, a solid electrolyte carbon dioxide sensor can be used.

  According to this embodiment, when the person to be detected places the palm on the upper surface (mounting portion) of the housing 12, the gas diffused from the skin of the palm is stored in the storage chamber 14. At this time, the alcohol sensor 24A outputs a detection signal corresponding to the concentration of the ethanol gas component in the gas in the storage chamber 14, and an output as shown in FIG. 3A is obtained as a sensor response. The carbon dioxide sensor 24B outputs a detection signal corresponding to the concentration of carbon dioxide in the gas in the storage chamber 14, and a sensor output as shown in FIG. 3B is obtained as a sensor response.

  Detection signals output from the alcohol sensor 24A and the carbon dioxide sensor 24B are input to a computer 26 described later, and the ethanol concentration in the blood of the detection target person is detected based on the input detection signals. Note that the detection signals output from the alcohol sensor 24A and the carbon dioxide sensor 24B are simultaneously captured by the computer 26 at regular intervals.

  As shown in FIG. 4, the ethanol concentration detection device 10 is connected to the alcohol sensor 24A and the carbon dioxide sensor 24B, and detects the ethanol concentration in the blood of the detection subject and displays it on the display device 40. It has.

  The computer 26 includes a CPU, a ROM that stores a program for realizing an ethanol concentration detection processing routine that will be described later, a RAM that temporarily stores data, and a storage device such as an HDD. When the computer 26 is represented by functional blocks according to the ethanol concentration detection processing routine described below, the base value and saturation value of the concentration of ethanol gas are acquired based on the detection signal from the alcohol sensor 24A as shown in FIG. Based on the detection signal from the first sensor output acquisition unit 32 and the carbon dioxide sensor 24B, the second sensor output acquisition unit 34 that acquires the base value and saturation value of the concentration of carbon dioxide, and the amount of change in the concentration of ethanol gas And a blood concentration calculation unit 36 that calculates the ethanol concentration in the blood based on the amount of change in the concentration of carbon dioxide and outputs it to the display device 40.

  Next, the principle of calculating blood ethanol concentration in the present embodiment will be described.

  First, as shown in FIG. 5, a volatile substance such as ethanol diffuses from the blood to the subcutaneous tissue (tissue fluid), and a part thereof is released from the skin to the outside of the body. The degree of diffusion from the blood into the skin through the subcutaneous tissue is represented by a diffusion coefficient α, which is determined according to the molecular weight. When the ethanol concentration in the blood is X%, the ethanol gas concentration in the gas diffused into the skin through the subcutaneous tissue is αX%.

  In addition, as shown in FIG. 6, there is a proportional relationship between the blood concentration and the gas concentration released as skin gas if an individual is specified. Thus, the blood concentration cannot be accurately estimated. This is because the degree of diffusion from the blood through the subcutaneous tissue and skin changes because the subcutaneous fat and skin stratum corneum differ from person to person and the skin temperature changes depending on the environmental temperature.

  Therefore, in the present embodiment, attention is paid to the fact that carbon dioxide and oxygen in blood and subcutaneous tissue exist at a stable concentration, and these are water-soluble and diffuse from the skin, and are subcutaneously applied. Since it is affected by fat and skin temperature in the same manner as ethanol (diffusion coefficient is close to that of ethanol), this is used as a reference gas to take a ratio with the gas concentration of the detection target substance. Thereby, the influence by the above-mentioned individual difference and the change of environmental temperature, and the influence by the change of a diffusion coefficient can be reduced significantly.

The general formula for calculating the ethanol concentration in blood is represented by the following formula (1).
f (EtOH) _blood = a × f (EtOH) _skin / (CO ₂ ) _skin
... (1)

However, (EtOH) _blood is the ethanol concentration in blood, (EtOH) _skin is the concentration of ethanol gas in skin gas, and (CO ₂ ) _skin is the carbon dioxide concentration in skin gas, a is a coefficient determined in advance.

The blood concentration calculation unit 36 calculates the blood ethanol concentration according to the following equation (2) as a calculation example using the equation (1).
(EtOH) _blood = a × (ΔEtOH) _skin / (ΔCO ₂ ) _skin
= A x {(EtOH) _sat- (EtOH) _base }
/ {(CO ₂ ) _sat − (CO ₂ ) _base }
... (2)

However, (EtOH) _sat is a saturated value of ethanol gas concentration (alcohol concentration when storing skin gas), and (EtOH) _base is a base value of ethanol gas concentration (ethanol gas concentration in the atmosphere). Further, (CO ₂ ) _sat is a saturation value of carbon dioxide concentration (carbon dioxide concentration at the time of storing skin gas), and (CO ₂ ) _base is a base value of carbon dioxide concentration (carbon dioxide concentration in the atmosphere). Yes, a is a coefficient obtained in advance. In addition, what is necessary is just to use the average value or the minimum value of the arbitrary sections before skin gas input as each base value of ethanol gas concentration and carbon dioxide concentration, for example.

  As shown in the above equation (2), the ethanol concentration in the blood is calculated by multiplying the ratio between the change in the concentration of ethanol gas and the change in the concentration of carbon dioxide by a predetermined coefficient. Is done.

Next, the operation of the ethanol concentration detection apparatus 10 according to the first embodiment will be described.
When the main switch (not shown) of the ethanol concentration detection device 10 is turned on, the ethanol concentration detection processing routine shown in FIG. 7 is executed in the computer 26 of the ethanol concentration detection device 10.

  First, in step 100, a detection signal is acquired from each of the alcohol sensor 24A and the carbon dioxide sensor 24B and stored in a memory (not shown). In step 102, from the change in the detection signal from the carbon dioxide sensor 24B, the skin is detected. It is determined whether or not gas has been input into the storage chamber 14. If the carbon dioxide concentration obtained from the detection signal of the carbon dioxide sensor 24B is less than the threshold value, it is determined that the palm is not placed on the top surface of the housing 12 and skin gas is not input, and the process returns to step 100 above. . On the other hand, when the carbon dioxide concentration obtained from the detection signal of the carbon dioxide sensor 24B is equal to or higher than the threshold value, it is determined that the palm is placed on the upper surface of the housing 12 and skin gas is input, and the process proceeds to step 104.

  In step 104, based on the detection signals of the alcohol sensor 24A and the carbon dioxide sensor 24B acquired in step 100, it is determined whether or not both sensor outputs have reached saturation values. If at least one sensor output of the alcohol sensor 24A and the carbon dioxide sensor 24B has not reached the saturation value, the process returns to step 100. On the other hand, the sensor outputs of both the alcohol sensor 24A and the carbon dioxide sensor 24B are saturated. If the value is reached, go to step 106.

  In step 106, based on the time-series data of the detection signals of the alcohol sensor 24A and the carbon dioxide sensor 24B stored in step 100, ethanol is detected from the detection signal before the time when it is determined that skin gas is input. The base value of the gas concentration and the base value of the carbon dioxide concentration are acquired. Further, the saturation value of the ethanol gas concentration and the saturation value of the carbon dioxide concentration are acquired from the detection signal when the sensor output is saturated.

  In the next step 108, based on the base value and saturation value of the ethanol concentration and the base value and saturation value of the carbon dioxide concentration obtained in step 106, according to the above equation (2), Calculate the ethanol concentration.

  In step 110, the ethanol concentration in blood calculated in step 108 is displayed on the display device 40, and the ethanol concentration detection processing routine is terminated.

  As described above, according to the ethanol concentration detection apparatus according to the first embodiment, individual differences, etc., based on the ratio of the change in the concentration of ethanol gas diffused from the skin and the change in the concentration of carbon dioxide. The concentration of ethanol in blood can be accurately detected from skin gas.

  In addition, by adopting carbon dioxide having a diffusion coefficient close to that of ethanol as a reference gas, the influence of changes in the diffusion coefficient can be reduced and the concentration of ethanol in blood can be detected with high accuracy.

  In addition, the person to be detected puts the skin of the palm on the storage chamber of the housing so that simultaneous measurement is performed by the alcohol sensor and the carbon dioxide sensor in the storage chamber, and the detection value by the alcohol sensor is detected by the carbon dioxide sensor. In this way, the influence of individual differences can be reduced and the ethanol concentration in the blood can be accurately detected. In addition, it is possible to determine the drinking level by a simple operation.

  In the above embodiment, the case where the concentration of ethanol gas is detected using an electrochemical alcohol sensor is described as an example. However, the present invention is not limited to this, and an oxide semiconductor alcohol sensor is used. May be.

  Next, an ethanol concentration detection apparatus according to the second embodiment will be described. In addition, about the part which becomes the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The second embodiment is mainly different from the first embodiment in that the concentration of ethanol gas and the concentration of carbon dioxide are detected using a light absorption type sensor.

  As shown in FIG. 8, the ethanol concentration detection apparatus 210 according to the first embodiment includes an absorption spectrum (wavelength 9.5 μm) due to ethanol CO stretching vibration at the bottom of the storage chamber 14 of the housing 12. An optical filter 222A composed of a band-pass filter that transmits infrared rays in a predetermined wavelength band (for example, a wavelength band of 9 μm to 10 μm having an absorption spectrum due to CO stretching vibration of ethanol as a center wavelength) and the optical filter 222A are transmitted. And an ethanol photoelectric conversion element 224A configured by a bolometer, an SOI diode, a thermopile, or the like that converts the infrared ray into an electrical signal and outputs an electrical signal corresponding to the amount of transmitted light. Further, infrared rays in a predetermined wavelength band (for example, a predetermined wavelength band of 14 μm to 16 μm having a central wavelength of 15 μm) including an absorption spectrum due to CO stretching vibration of carbon dioxide are transmitted to the bottom of the storage chamber 14 of the housing 12. An optical filter 222B for carbon dioxide and a photoelectric conversion element 224B for carbon dioxide configured by a bolometer, an SOI diode, a thermopile, or the like that converts infrared light transmitted through the optical filter 222B into an electrical signal are provided. The optical filter 222A and the ethanol photoelectric conversion element 224A are examples of target gas detection means. The optical filter 222B and the carbon dioxide photoelectric conversion element 224B are examples of the reference gas detection unit.

  A computer 26 is connected to the ethanol photoelectric conversion element 224A and the carbon dioxide photoelectric conversion element 224B.

  The wavelength band of infrared rays emitted from human skin is about 2 μm to 100 μm at a temperature of 300 ° K. Moreover, since the direction of the infrared rays emitted from the skin of the palm placed on the upper surface of the housing 12 is the same as the diffusion direction of the gas diffused from the skin, the ethanol gas in the storage chamber 14 and the skin The emitted infrared rays interact between the palm skin and the ethanol concentration detection device 210.

  Therefore, according to the ethanol concentration detection device 210 of the present embodiment, due to the interaction of the infrared rays emitted from the skin of the palm of the detection subject and the ethanol gas in the storage chamber 14, due to the C—O stretching vibration of ethanol. An absorption spectrum is generated, and the intensity of infrared rays in a predetermined wavelength band including the absorption spectrum is reduced.

  The intensity Te of the electrical signal output from the ethanol photoelectric conversion element 224A, that is, the amount of transmitted infrared light transmitted through the optical filter 222A is expressed by the following equation (3).

    Te = ToEXP (−ne · ke · L) (3)

Where To is the light amount of the palm as a light source, ne is the concentration of ethanol gas, ke is the absorption coefficient of ethanol gas, and L is the interaction length between the gas and light (the distance from the optical filter 222A to the palm placed) EXP represents an exponential function.

  From the above equation (3), the concentration of ethanol gas (EtOH) in the storage chamber 14 is expressed by the following equation (4).

(EtOH) = ne = −ln (Te / To) / ke · L (4)
Here, ln represents a natural logarithm.

  Therefore, the first sensor output acquisition unit 32 of the computer 26 calculates the ethanol gas concentration (EtOH) in the storage chamber 14 according to the above equation (4), and acquires the base value and saturation value of the ethanol gas concentration.

  Further, the concentration of carbon dioxide (CO2) in the storage chamber 14 is expressed by the following equation (5).

    (CO2) = − ln (Tc / To) / kc · L (5)

However, Tc is the amount of transmitted light obtained from the electrical signal output from the carbon dioxide photoelectric conversion element 224B, and kc is the absorption coefficient of carbon dioxide.

  The second sensor output acquisition unit 34 of the computer 26 calculates the concentration (CO2) of carbon dioxide in the storage chamber 14 according to the above equation (5), and acquires the base value and saturation value of the concentration of carbon dioxide.

  In addition, about the other structure and effect | action of the ethanol concentration detection apparatus 210 which concern on 2nd Embodiment, since it is the same as that of 1st Embodiment, description is abbreviate | omitted.

  Next, an ethanol concentration detection apparatus according to a third embodiment will be described.

  The ethanol concentration detection apparatus according to the third embodiment includes an elongated cylindrical skin gas introduction tube having a placement portion for placing the palm on the tip, and is provided in the middle of the skin gas introduction tube. A sensor group 24 is attached inside the unit. The alcohol sensor 24A and the carbon dioxide sensor 24B of the sensor group 24 are attached so as to face the inside of the intermediate part of the skin gas introduction pipe.

  The alcohol sensor 24A detects ethanol gas contained in the gas flowing through the skin gas introduction tube. The carbon dioxide sensor 24B detects carbon dioxide contained in the gas flowing through the skin gas introduction pipe.

  Further, a suction fan that is driven to suck skin gas from the suction port is provided inside the skin gas introduction pipe and closer to the suction port than the alcohol sensor 24A and the carbon dioxide sensor 24B.

  In addition, since it is the same as that of 1st Embodiment about the other structure and effect | action of the ethanol concentration detection apparatus 210 which concern on 3rd Embodiment, description is abbreviate | omitted.

  In the first to third embodiments, the case where the detected ethanol concentration in blood is displayed has been described as an example. However, the present invention is not limited to this. Compare the ethanol concentration in the blood with a predetermined threshold value, and if the detected ethanol concentration in the blood is equal to or greater than the threshold value, determine that the ethanol concentration is high and prevent the engine from starting up. You may make it control to.

  Next, a fourth embodiment will be described. In the fourth embodiment, a case where the present invention is applied to an acetone concentration detection device that detects the concentration of acetone as a detection target substance in blood will be described as an example. In addition, about the part which becomes the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The acetone concentration detection apparatus according to the fourth embodiment includes a housing 12 in which a storage chamber 14 is formed, and is attached to the bottom of the storage chamber 14 so as to detect gas in the storage chamber 14. It consists of an acetone sensor and a carbon dioxide sensor 24B.

  The acetone sensor is a sensor that detects acetone gas contained in the gas in the storage chamber 14, and has high sensitivity to the acetone gas.

  In the computer 26 connected to the acetone sensor and the carbon dioxide sensor 24B, the first sensor output acquisition unit 32 acquires the base value and saturation value of the concentration of acetone gas based on the detection signal from the acetone sensor.

  Further, in the present embodiment, attention is paid to the fact that carbon dioxide and oxygen in blood and subcutaneous tissue are present at a stable concentration, and these are water-soluble, diffuse from the skin, and subcutaneously. As it is affected by fat and skin temperature in the same way as acetone (diffusion coefficient is close to acetone), taking this as a reference gas and taking a ratio with the concentration of acetone gas, the effect of individual differences and changes in environmental temperature In addition, the influence of changes in the diffusion coefficient is greatly reduced.

The blood concentration calculation unit 36 calculates the blood acetone concentration according to the following equation (6).
(C ₃ H ₆ O) _blood = a × (ΔC ₃ H ₆ O) _skin / (ΔCO ₂ ) _{skin
= A × {(C 3 H} 6 O) sat - (C 3 H 6 O) base}
/ {(CO ₂ ) _sat − (CO ₂ ) _base }
... (6)

However, (C ₃ H ₆ O) _sat is a saturated value of acetone gas concentration (acetone gas concentration during skin gas storage), and (C ₃ H ₆ O) _base is a base value of acetone gas concentration (in the atmosphere) A) is a coefficient determined in advance.

  As shown in the above equation (6), the acetone concentration in the blood is calculated based on the ratio between the change amount of the acetone gas concentration and the change amount of the carbon dioxide concentration.

  In addition, about the other structure and effect | action of an acetone concentration detection apparatus based on 4th Embodiment, since it is the same as that of 1st Embodiment, description is abbreviate | omitted.

  As described above, according to the acetone concentration detection device according to the fourth embodiment, based on the ratio of the change in the concentration of acetone gas diffused from the skin and the change in the concentration of carbon dioxide, individual differences, etc. The concentration of acetone in blood can be accurately detected from skin gas. In addition, the physical condition can be determined by a simple operation.

  In the above embodiment, the contents described in the second embodiment and the contents described in the third embodiment may be applied.

  Moreover, in said 1st Embodiment-4th Embodiment, although the case where the density | concentration of a carbon dioxide was detected as a reference gas was demonstrated to the example, it is not limited to this, The blood concentration The concentration of oxygen that is stable, has a diffusion coefficient close to that of ethanol or acetone, has water solubility, and is diffused from the skin may be detected. In this case, it is configured using a solid electrolyte type or Clark electrode type oxygen sensor, and using the ratio of the change in the concentration of ethanol gas or acetone gas to the change in the concentration of oxygen, ethanol in the blood is used. What is necessary is just to calculate a density | concentration and acetone density | concentration.

  In addition, a case where the saturation value is obtained together with the base value of the ethanol gas concentration or the acetone gas concentration, and the blood ethanol concentration or the acetone concentration is calculated using the change amount of the ethanol gas concentration or the acetone gas concentration is described as an example. However, the present invention is not limited to this, and the peak value of the ethanol gas concentration or the acetone gas concentration may be acquired to obtain the change amount of the ethanol gas concentration or the acetone gas concentration. In this case, the peak value of the carbon dioxide concentration is obtained, the amount of change in the carbon dioxide concentration is obtained, and the ethanol concentration or acetone concentration in the blood may be calculated from the ratio of these changes. Also, the ethanol gas concentration or acetone gas concentration change rate is obtained, and the blood ethanol concentration or acetone concentration is calculated from the ratio of the ethanol gas concentration or acetone gas concentration change rate and the carbon dioxide concentration change rate. You may do it.

  Moreover, although the case where the skin gas diffused from the skin of the palm of the detection target is detected has been described as an example, the present invention is not limited to this, and the skin gas diffused from the skin of other parts of the detection target May be detected. For example, you may make it detect the skin gas diffused from the skin of a finger | toe of a detection subject.

DESCRIPTION OF SYMBOLS 10 Ethanol concentration detection apparatus 12 Case 14 Storage chamber 24A Alcohol sensor 24B Carbon dioxide sensor 26 Computer 32 1st sensor output acquisition part 34 2nd sensor output acquisition part 36 Blood concentration calculation part 210 Ethanol concentration detection apparatus 222A Optical filter 222B Carbon dioxide Optical filter for carbon 224A Photoelectric conversion element for ethanol 224B Photoelectric conversion element for carbon dioxide

Claims (5)

Target gas detection means for detecting the concentration of the detection target gas in which the detection target substance in the blood of the detection target diffuses as a gas from the skin; and
A reference gas detection means for detecting a concentration of a reference gas having a stable blood concentration and having water solubility and diffusing from the skin;
Based on the concentration of the detection target gas detected by the target gas detection means and the concentration of the reference gas detected by the reference gas detection means, the blood concentration for calculating the concentration of the detection target substance in the blood A calculation means;
A skin gas detection device including:   The skin gas detection device according to claim 1, wherein a diffusion coefficient indicating a degree of diffusion of the reference gas from blood into skin is correlated with a diffusion coefficient of the detection target substance. It further includes a housing part for placing a predetermined part of the detection subject and a storage chamber for storing gas diffused from the skin of the predetermined part,
The target gas detection means detects the concentration of the detection target gas in the storage chamber,
The skin gas detection device according to claim 1 or 2, wherein the reference gas detection means detects a concentration of the reference gas in the storage chamber. The skin gas detection device according to any one of claims 1 to 3, wherein the blood concentration calculation means calculates the concentration of the detection target substance in blood according to the following equation.
Concentration of the detection target substance in blood = a × (ΔGas) / (ΔRef)
Where ΔGas is the amount of change in the concentration of the detection target gas detected by the target gas detection means, ΔRef is the amount of change in the concentration of the reference gas detected by the reference gas detection means, and a is a coefficient.   The skin gas detection device according to any one of claims 1 to 4, wherein the detection target substance is one of ethanol and acetone.

Images