TWI766640B - Evaluation method and detection device for blood glucose concentration - Google Patents

Abstract

A method for evaluating blood glucose concentration for users to measure in a non-invasive manner, including the steps of breath capture and measurement, and the steps of blood glucose evaluation. The expiratory capture and measurement step is to capture the final expiratory volume of an expiratory gas exhaled by the user in a continuous time interval, and the final expiratory volume is not greater than the total expiratory volume of the expiratory gas 10%, and measure the carbon dioxide concentration of the end expiratory flow to estimate the user's blood sugar concentration. Next, in the blood glucose assessment step, blood glucose assessment is performed by using the carbon dioxide concentration in the final exhalation extracted from the expiratory gas, so that the interference of dead space gas in the expiratory gas can be excluded, thereby improving the accuracy of the assessment. In addition, the present invention also provides a detection device for carrying out the aforementioned evaluation method.

Description

Evaluation method and detection device for blood glucose concentration

The present invention relates to an evaluation method and a detection device for blood glucose concentration, in particular to a non-invasive evaluation method and detection device for blood glucose concentration.

When breathing, the breathed gas will be exchanged with the blood in the alveoli, so the gas exhaled by a person will have a certain degree of correlation with the components in the blood. At present, in laboratory medicine, specific gas analysis is often performed on the exhaled gas of the subject to test whether the subject suffers from related diseases such as lung disease, asthma or liver problems, and thus to evaluate the subject. The health status of the subjects in order to facilitate the subsequent treatment and management of the disease. Among them, since the carbon dioxide (CO ₂ ) concentration in the exhaled gas is positively correlated with the blood glucose concentration, by measuring the carbon dioxide concentration in the exhaled gas of the subject, the blood glucose concentration of the subject can be further inferred, and this Determine whether the subject has blood sugar metabolism, diabetes and other related diseases. Japanese Invention Patent No. JP6352188B2 Approval Announcement No. JP6352188B2 discloses a method for determining the ability of glucose metabolism. After the tester takes glucose labeled with isotope C, the carbon dioxide concentration in the exhaled breath of the tester is measured at different time points. And observe the content of carbon dioxide marked with isotope C in the total carbon dioxide gas to evaluate the ability of the tester to metabolize sugar.

Based on the convenience of non-invasive detection methods and detection procedures, the aforementioned method of measuring exhaled gas to assess blood glucose has been widely studied in related fields. In addition to the gas, it also includes the gas from the oral cavity, respiratory tract and bronchi. Such gas is called dead space gas in medicine, and does not participate in the exchange between breathing gas and blood in the alveoli, so it is invalid. The presence of the cavity gas will cause errors in the detection method of judging the blood glucose concentration by the carbon dioxide concentration, and cause insufficient accuracy in evaluating the blood glucose concentration of a patient or diseases such as diabetes.

Therefore, the purpose of the present invention is to provide a method for evaluating blood glucose concentration, so as to improve the accuracy of evaluating blood glucose concentration.

Therefore, the method for evaluating the blood glucose concentration of the present invention, for a user to evaluate the blood glucose condition in a non-invasive manner, includes a breath capture measurement step and a blood glucose evaluation step.

The breath capturing and measuring step is to capture a final expiratory volume of an expiratory gas exhaled by the user in a continuous time interval T ₀ ~T _n , and measure the carbon dioxide concentration of the final expiratory volume, Among them, T ₀ is an expiratory start time, T _n is an expiratory end time, and the final expiratory volume is captured from the time between an initial capture time T _X1 and an end capture time T _X2 interval, and T ₀ <T _X1 , T _X1 <T _X2 ≦T _n , X1, X2, and n are natural numbers, and the final expiratory volume is not greater than the total expiratory volume in the continuous time interval T ₀ ~T _n 10%.

The blood glucose assessment step is to calculate and estimate the blood glucose concentration of the user by using the carbon dioxide concentration of the final expiratory volume to obtain a blood glucose assessment result.

Another object of the present invention is to provide a detection device suitable for measuring carbon dioxide concentration in a non-invasive manner to obtain blood glucose assessment results.

Therefore, the detection device of the present invention, for a user to detect the blood glucose concentration in a non-invasive manner, includes a gas trapping unit, a converting unit, a sensing unit, and an analyzing unit.

The gas trapping unit includes a hollow tube body with an air inlet for receiving the exhaled gas exhaled by the user, and a discharge port away from the air inlet for discharging the exhaled gas breath.

The conversion unit includes an audio frequency converter, the audio frequency converter is arranged in the hollow tube body and communicated with the air inlet, the exhalation gas introduced from the air inlet can enter the audio frequency converter at the same time, the audio frequency converter The exhaled gas entering at different times can be converted into different sound wave signals according to the gas volume.

The sensing unit is disposed in the hollow tube and includes at least one gas sensor for sensing the carbon dioxide concentration in the exhaled gas.

The analysis unit is respectively connected with the sensing unit and the conversion unit signal, A time-dependent gas volume signal of the expiratory gas can be calculated by using the acoustic wave signals obtained at different times, and the carbon dioxide measured by the sensing unit in a specific time period can be obtained by using the result of the time-dependent gas volume signal concentration.

The effect of the present invention is that: the final expiratory volume is extracted from the expiratory gas through the exhalation extraction step, so as to eliminate the interference of dead space gas from the oral cavity, respiratory tract or bronchus, etc., and can only be based on the measured The obtained carbon dioxide concentration at the end of exhalation can be used to evaluate blood glucose, thereby improving the accuracy of the evaluation.

200: Detection device

2: Gas trapping unit

21: Hollow body

211: Air intake

212: exhaust port

22: Exhaust parts

3: Conversion unit

31: Audio Converter

32: Receiver

4: Sensing unit

41: Gas sensor

5: Analysis unit

60: Pre-assessment step

61: Exhalation capture measurement steps

62: Blood Glucose Assessment Steps

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein: FIG. 1 is a schematic diagram illustrating an embodiment of the detection device of the present invention; FIG. 2 is a flow chart illustrating the present invention A first embodiment of a method for evaluating blood glucose concentration; FIG. 3 is a graph showing the relationship between the exhaled carbon dioxide concentration and the blood glucose concentration value, illustrating the relationship between the carbon dioxide concentration in the user's exhaled air measured by the first embodiment and its own relationship of blood glucose concentration; and FIG. 4 is a flowchart illustrating a second embodiment of the method for evaluating blood glucose concentration of the present invention.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are designated by the same reference numerals.

Referring to FIG. 1 , the method for evaluating the blood glucose concentration of the present invention can use a non-invasive detection device 200 for the user to evaluate the blood glucose concentration in a non-invasive manner.

The detection device 200 includes a gas trapping unit 2 , a converting unit 3 , a sensing unit 4 , and an analyzing unit 5 .

The gas trapping unit 2 includes a hollow tube body 21 and an exhaust member 22. The hollow tube body 21 has an air inlet 211 for receiving the exhaled air exhaled by the user, and an air inlet remote from the air inlet. Port 211 is an exhaust port 212 for discharging the exhaled gas. The exhaust member 22 communicates with the exhaust port 212 for forcibly discharging the exhaled gas entering the hollow tube body 21 to the outside. The flow rate of the exhaust gas is controlled by the exhaust member 22, so that the hollow tube body 21 maintains the state of gas flow during the detection process, so that the exhalation gas is discharged from the exhaust port 212 according to time during the exhalation process. In order to avoid gas accumulation, it can be used to control only the expiratory gas for a specific time interval to be retained in the hollow tube body 21 . In this embodiment, the exhaust member 22 is a fan disposed at the exhaust port 212 as an example, but it is not limited thereto.

The conversion unit 3 includes an audio frequency converter 31 and a receiver 32 . The audio frequency converter 31 is arranged in the hollow tube body 21 and communicates with the air inlet 211 . Exhaled air introduced from the air inlet 211 Gas can enter the audio converter 31 at the same time, the audio converter The converter 31 can convert the exhaled gas into different sound wave signals according to the amount of gas blown in at different times; the receiver 32 is arranged adjacent to the sound frequency converter 31 for receiving the sound wave signals, and can be used for receiving and amplify these acoustic signals. The audio transducer 31 can be selected from whistle sound generators. In this embodiment, the audio converter 31 is a whistle sound generator and the receiver 32 is a microphone as an example, but it is not limited thereto.

The sensing unit 4 is disposed in the hollow tube body 21 and includes at least one gas sensor 41 for sensing the carbon dioxide concentration in the exhaled gas. In this embodiment, the sensing unit 4 is provided with a gas sensor 41 for measuring the concentration of carbon dioxide, and the gas sensor 41 is disposed in the hollow tube at a position adjacent to the exhaust port 212 As an example, however, in actual implementation, the number and installation positions of the gas sensors 41 are not limited to the aforementioned implementations.

In some embodiments, the sensing unit 4 may have two gas sensors 41 for measuring the carbon dioxide concentration and the oxygen concentration in the exhaled gas respectively, so as to simultaneously measure and obtain the carbon dioxide concentration in the exhaled gas, and oxygen concentration.

The analysis unit 5 is respectively connected to the sensing unit 4 and the conversion unit 3 for signals, and can receive the carbon dioxide concentration sensing results of the sensing unit 4 at different times to obtain a time-dependent concentration signal; the analysis unit 5 uses the receiving The conversion unit 3 obtains a time-dependent gas volume signal of the expiratory gas by calculating the sound wave signals obtained at different times, and can use the time-dependent gas volume signal to calculate and obtain the total expiratory volume and final expiratory volume , and the end expiratory time interval corresponding to the end expiratory volume to further obtain the sense of The carbon dioxide concentration measured by the measuring unit 4 in the time interval corresponding to the final exhalation. Specifically, the analysis unit 5 obtains the total expiratory volume of the expiratory gas through the integral calculation of the time-dependent gas volume signal and time, and then obtains the final expiratory volume through the calculation of the total expiratory volume, and obtains correspondingly. The measurement time interval of the final expiratory volume, and then, by comparing the time-dependent concentration signal of the carbon dioxide, the carbon dioxide concentration of the expired gas in the measurement time interval of the final expiratory volume can be obtained.

Referring to FIGS. 1 and 2 , a first embodiment of the method for evaluating blood glucose concentration of the present invention is for the user to use the aforementioned detection device 200 to detect the carbon dioxide concentration of exhaled gas, and to evaluate his own blood glucose concentration accordingly. . The first embodiment includes a breath capture measurement step 61 and a blood glucose assessment step 62 .

The breath capture and measurement step 61 is to capture the final expiratory volume of the expiratory gas exhaled by the user in a continuous time interval T ₀ -T _n , and to measure the carbon dioxide in the final expiratory volume. concentration. Among them, T ₀ is an expiratory start time, T _n is an expiratory end time, and n is a natural number. The final expiratory volume is obtained from a final expiratory time interval, and the final expiratory time interval is between a start capture time T _X1 and an end capture time T _X2 , T ₀ <T _X1 , T _X1 <T _X2 ≦T _n , X1, X2, and n are natural numbers, and the final expiratory volume Not more than 10% of the total expiratory volume in the continuous time interval T ₀ ~T _n . That is to say, the final expiratory volume is the expiratory volume obtained from a time interval before the expiration time (ie, the final expiratory time interval).

The blood glucose assessment step 62 is to use the carbon dioxide concentration of the end expiratory volume The calculation estimates the blood glucose concentration of the user.

More specifically, the breath capture and measurement step 61 is to make the user exhale through the air inlet 211 of the hollow tube 21, and let the exhaled gas pass through the air inlet 211, the audio frequency conversion The device 31 is introduced into the hollow tubular body 21 . The sensing unit 4 continuously senses the carbon dioxide concentration in the exhaled gas entering the hollow tube 21 to obtain a time-dependent change in carbon dioxide concentration corresponding to the continuous time interval T ₀ -T _n . At the same time, the exhaled gas entering the hollow tube body 21 can generate sound wave signals with different intensities and frequencies through the audio frequency converter 31, and because the sound wave signals with different frequencies and intensities correspond to different gas volumes, it can be The analysis unit 5 converts the acoustic wave signals into the time-dependent gas volume signal, and utilizes the integral calculation of the time-dependent gas volume signal and time to obtain the expiratory gas corresponding to the continuous time interval T ₀ ~T _n The total expiratory volume and/or the gas volume in a specific time period (equivalent to the time-dependent gas volume of the expiratory gas), then the final expiratory volume can be calculated using the total expiratory volume, and Accordingly, the start capture time T _X1 and the end capture time T _X2 of the final expiratory time interval are defined. Afterwards, the carbon dioxide concentration in the exhaled air of the user in the final exhalation time interval can be obtained by using the time-dependent concentration change result of carbon dioxide.

Finally, the carbon dioxide concentration (average value) in the final expiratory time interval can be used to compare with a standard value of blood glucose level to obtain the blood glucose evaluation result. For example, if the total expiratory volume calculated by the user after exhalation is 2L, the final expiratory volume of the user is not more than 200ml (not more than 10% of the total expiratory volume). From the time gas volume signal, the start capture time T _X1 and the end capture time T _X2 corresponding to the final expiratory volume can be obtained. Then, the carbon dioxide concentration in the last exhalation time interval of the user can be obtained by comparing the initial capture time T _X1 and the end capture time T _X2 with the time-dependent concentration change results of carbon dioxide. The blood glucose assessment result can be obtained by comparing the carbon dioxide concentration result with the corresponding standard blood glucose concentration value.

Since the measurement of the overall carbon dioxide concentration of the user's exhaled gas is used as the basis for evaluating the blood glucose concentration, the first exhaled gas of the user also contains dead space gas from the oral cavity, respiratory tract and bronchi, and the dead space gas Because there is no respiratory exchange between the lungs and the blood, the accuracy of carbon dioxide concentration measurement will be affected. Therefore, the present invention only measures the carbon dioxide concentration of the user's expiratory volume at the end of the exhalation process. The expiratory volume is the gas that the user exhales at the end of the entire exhalation process, so it can avoid the interference of the dead space gas on the carbon dioxide concentration measurement, and can improve the accuracy of the carbon dioxide concentration measurement to improve the blood sugar assessment. accuracy. It should be noted that the total expiratory volume (equivalent to vital capacity) will vary according to different ages, physiological conditions, etc., and the final expiratory volume is based on the fact that the essence is not greater than 10% of the total expiratory volume.

The aforementioned first embodiment utilizes the time-dependent concentration result of continuously measuring the carbon dioxide in the user's exhaled breath during the exhalation process, and then uses the captured carbon dioxide concentration in the final exhalation time interval to evaluate the blood glucose level. Of course, in actual implementation, it is not necessary to continuously measure the concentration of carbon dioxide in the exhaled breath, but can be based on the data before the measurement. According to the evaluation result, only measuring the concentration of carbon dioxide in the end exhalation time interval of the user can also achieve the purpose of the present invention. This method will be illustrated in the following second embodiment.

Referring to FIG. 1 and FIG. 4 , the second embodiment of the blood glucose concentration assessment method of the present invention includes a pre-assessment step 60 , the breath capture measurement step 61 , and the blood glucose assessment step 62 .

In the pre-evaluation step 60, the detection device 200 is used to capture the exhaled gas exhaled by the user in a previous continuous time interval T ₀ -T _n , and the analysis unit 5 performs time integration calculation to obtain the usage The total expiratory volume and/or the time-dependent gas flow in the continuous time interval T ₀ ~T _n , calculate the final expiratory volume through the total expiratory volume, and use the final expiratory volume to obtain a corresponding A final expiratory time interval is obtained, and a preset start acquisition time and a preset end acquisition time of the final expiratory time interval are obtained.

Next, the expiratory capture measurement step 61 is performed. The difference from the first embodiment is that the pre-evaluation step 60 has already estimated the preset start capture of the end exhalation time interval of the user. time and the preset end capture time, therefore, the gas capture measurement step 61 of the second embodiment uses the preset start capture time and the preset end time defined from the pre-evaluation step 60 The capture time is taken as the start capture time T _X1 and the end capture time T _X2 of the final expiratory volume of the current measurement, and only the user needs to measure the entire exhalation process of the current time , the carbon dioxide concentration in the time interval from T _X1 to T _X2 is sufficient, and it is not necessary to continuously measure the carbon dioxide concentration of the user's exhalation during the entire exhalation process. Finally, through the blood glucose evaluation step 62, the measured carbon dioxide concentration in the final expiratory time interval can be compared with the corresponding standard blood glucose value to obtain a blood glucose evaluation result.

In some embodiments, in the pre-evaluation step 60, the preset start acquisition time and the preset start acquisition time and the The preset end capture time, wherein the preset value of total expiratory volume and the preset value of expiratory time are set according to one of the user's age, gender or other physiological characteristics, or an existing database .

The detection method in this case can evaluate the user's blood sugar status by observing the overall change trend of the end-expiratory carbon dioxide concentration measured by the user at different time points. The carbon dioxide concentration in the final exhalation continued to increase with time, and there was no sign of decrease after about 2 hours, indicating that the user's blood sugar concentration was very high, and there may be a problem of insufficient glucose metabolism.

Referring to FIG. 3 , the relationship between the carbon dioxide concentration and the blood glucose concentration value in the final exhalation can be obtained by allowing the user to perform an Oral glucose tolerance test (OGTT). First, make the user take 75 grams of glucose on an empty stomach; then, within 120 minutes, let the user use the detection device 200 to measure the carbon dioxide concentration of the final exhalation every 30 minutes, At the same time, the blood glucose concentration value of the user was measured (see Table 1). Figure 3 shows the user's Glucose tolerance test was performed, and the carbon dioxide concentration (solid line) and the blood glucose concentration (dotted line) were measured at different time points before and after eating glucose. It can be found from FIG. 3 that the carbon dioxide concentration and the blood glucose concentration in the end expiratory time interval are positively correlated. Therefore, through the measurement results of the carbon dioxide concentration in the final exhalation and the blood glucose concentration of the user, a relationship curve between the carbon dioxide concentration in the final exhalation and the blood glucose concentration can be established. Subsequently, the carbon dioxide concentration measured by the detection method of the present invention can obtain the corresponding blood sugar concentration value through the interpolation method, and finally, the blood sugar concentration value is compared with a standard blood sugar concentration value, and the blood sugar evaluation result can be obtained, For example, after about 120 minutes of eating, the standard blood glucose concentration should be no more than 200 mg/dL. If about 120 minutes after the user eats, the blood glucose concentration calculated from the carbon dioxide concentration in the final exhalation measured by the present invention is 210 mg/dL, which is exceeded after comparing with the standard blood glucose concentration, indicating that the user is using The patient may have the problem of insufficient glucose metabolism, and should go to a medical institution for medical examination as soon as possible. In addition, it should be noted that the corresponding relationship between the carbon dioxide concentration and the blood glucose concentration value may also be obtained from an existing database.

To sum up, the method for evaluating blood glucose concentration of the present invention uses the breath capture In step 61, the final exhalation is extracted from the exhaled gas to measure the carbon dioxide concentration for blood glucose assessment, and the interference from the dead space gas such as the oral cavity, respiratory tract or bronchus is excluded, thereby improving the accuracy of the blood glucose concentration assessment. In addition, the detection device 200 can be used for the user to perform blood glucose assessment in a non-invasive manner, and the detection process is simple, which is more conducive to the blood glucose assessment, and thus can indeed achieve the purpose of the present invention.

However, the above are only examples of the present invention, and should not limit the scope of implementation of the present invention. Any simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the contents of the patent specification are still included in the scope of the present invention. within the scope of the invention patent.

61: Exhalation capture measurement steps

62: Blood Glucose Assessment Steps

Claims (10)

A method for evaluating blood glucose concentration for a user to detect blood glucose concentration in a non-invasive manner, comprising: a breath capture and measurement step, capturing a breath exhaled by the user in a continuous time interval T ₀ ~T _n The final expiratory volume of the gas is measured, and the carbon dioxide concentration of the final expiratory volume is measured, wherein T ₀ is an expiratory start time, T _n is an expiratory end time, and the final expiratory volume captures Taken from a time interval between a start capture time T _X1 and an end capture time T _X2 , and T ₀ < T _X1 , T _X1 <T _X2 ≦T _n , X1, X2, and n are natural numbers, and The final expiratory volume is not greater than 10% of the total expiratory volume in the continuous time interval T ₀ ~T _n ; and a blood glucose assessment step, using the carbon dioxide concentration of the final expiratory volume to calculate and estimate the user's blood glucose concentration to obtain blood glucose assessment results. The method for assessing blood glucose concentration according to claim 1, wherein the blood glucose assessment step is to compare the blood glucose concentration estimated from the carbon dioxide concentration of the final expiratory volume with a standard blood glucose concentration value to obtain The results of the blood glucose assessment. The method for evaluating blood glucose concentration according to claim 1, wherein the expiratory capture and measurement step is to obtain the time-dependent gas flow results and total expiratory volume of the expiratory gas of the user in the continuous time interval, and the time-dependent concentration change result of the carbon dioxide in the expiratory gas in the continuous time interval, and determine the initial capture time T _X1 and the end capture time T _X2 of the final expiratory volume according to the total expiratory volume . The method for evaluating blood glucose concentration according to claim 1, further comprising a pre-evaluation step, wherein the pre-evaluation step is to obtain a preset start acquisition time and a preset end acquisition time for the user, In the expiratory capture measurement step, the preset start capture time and the preset end capture time are used as the start capture time T _X1 of the final expiratory volume, and the end capture time T _X2 , and only captures and measures the carbon dioxide concentration of the user in the final expiratory volume. The method for evaluating blood glucose concentration according to claim 4, wherein the pre-evaluation step is to measure the exhaled gas exhaled by the user in a previous continuous time interval to obtain the total amount of the user in the continuous time interval. expiratory volume, and use the total expiratory volume to obtain the preset start capture time and the preset end capture time of the final expiratory volume, and the expiratory capture measurement step starts from the preset The start capture time and the preset end capture time are taken as the start capture time T _X1 and the end capture time T _X2 of the final expiratory volume of the expiratory gas exhaled by the user at the current time . The method for evaluating blood glucose concentration according to claim 4, wherein the pre-evaluation step is obtained by calculating a preset value of total expiratory volume and a preset value of expiratory time related to the preset value of total expiratory volume The preset start capture time and the preset end capture time, and the breath capture measurement step uses the preset start capture time and the preset end capture time as the user's current capture time The start capture time T _X1 and the end capture time T _X2 of the final expiratory volume of the exhaled expiratory gas. The method for evaluating blood glucose concentration according to claim 6, wherein the preset value of total expiratory volume and the preset value of expiratory time are set according to one of the user's age, gender or other physiological characteristics. A detection device for a user to detect blood glucose concentration in a non-invasive manner, comprising: A gas trapping unit, including a hollow tube body, the hollow tube body has an air inlet for receiving the exhaled gas exhaled by the user, and an air inlet away from the air inlet for discharging the exhaled gas exhaust vent; A conversion unit, including an audio frequency converter, the audio frequency converter is arranged in the hollow tube body and communicated with the air inlet, the exhalation gas introduced from the air inlet can enter the audio frequency converter at the same time, the audio frequency conversion The device can convert the expiratory gas entering at different times into different sound wave signals according to the gas volume; a sensing unit disposed in the hollow tube and comprising at least one gas sensor for sensing the carbon dioxide concentration in the exhaled gas; and an analysis unit, which is connected to the sensing unit and the conversion unit respectively, and calculates a time-dependent gas volume signal of the expiratory gas by using the sound wave signals obtained at different times, and can use the result of the time-dependent gas volume signal The carbon dioxide concentration measured by the sensing unit in a specific time period is obtained. The detection device of claim 8, wherein the audio converter is a whistle sound generator, and the conversion unit further includes a receiver, which is disposed adjacent to the audio converter and used to receive the sound wave signal. The detection device according to claim 8, further comprising an exhaust member, the exhaust member communicates with the exhaust port of the hollow tube body and is used to forcibly discharge the exhaled gas entering the hollow tube body to the outside .

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