Devices and methods for measuring redox potential in vivo, as well as methods for verifying redox potential in vivo.

Abstract

In the formula for the redox potential E based on the Nernst equation, with the temperature set at 37℃ (310K), the redox potential E of hydrogen / hydrogen ions is E = -0.061 × pH + 0.031 × pH² (V). At pH = 7.4, E = -0.451 + 0.031 × pH² (V). The hydrogen index pH² of the test subject is measured, and E is calculated using the above formula. According to the potential verification method of the present invention, by blowing air and air containing hydrogen into phosphate buffer, measuring the potential before and after blowing, performing necessary corrections, and obtaining a linear regression line, the change in potential accompanying the change in hydrogen index pH² can be confirmed. It can be seen that the calculated redox potential is approximately the same as the actual redox potential.

Description

Technical Field

[0001] This invention relates to an apparatus for measuring redox potential in vivo, a method for measuring redox potential in vivo, and a method for verifying redox potential in vivo. Background Technology

[0002] Most metabolic reactions in living organisms are based on redox reactions involving electron transfer. Redox is a compound word combining reduction and oxidation. The redox potential is defined by the ratio of the oxidized to the reduced form (redox pair) at the equilibrium state of a redox reaction involving electron donation and acceptance. The Nernst equation represents the equilibrium electrode potential corresponding to the electrode reaction: E = E0 0 +(RT / nF)ln([Ox] a / [Red] b ):

[0003] [Chemical Formula 1]

[0004]

[0005] (Ox and Red represent the oxidized and reduced forms of the redox system, e- represents electrons, and a, b, and n represent the number of molecules or electrons). E 0 This is the standard electrode potential relative to the standard hydrogen electrode. As shown in Non-Patent Literature 1 below, in 1967, Williamson et al. studied nicotinamide dinucleotide NADH / NAD... + The respective metabolites of glutathione-2 (GSH) and GSSG were determined, and their redox potentials were measured. Additionally, in 2001, Shapiro et al. directly measured the concentrations of glutathione-2 (GSH) and GSSG, thereby determining their redox potentials. As shown in Non-Patent Literature 2 below, in 2002, Jones et al. reported that regarding the biological significance of redox potential, the redox potential of cultured cells is lowest during cell proliferation, median during differentiation (steady state), and increases during cell death, i.e., apoptosis, thus regulating cell function by controlling the redox state.

[0006] As shown in Non-Patent Literature 3 below, in 2019, Hatori observed a correlation between the redox state of intracellular glutathione and various diseases, pointing out that for the scale of redox balance, it is more intuitive and convenient to treat it as redox potential (mV) rather than as the concentration ratio (%) of glutathione. Redox balance and redox state were studied as oxidative stress caused by reactive oxygen species, and the intracellular local presence of glutathione oxidation sensors was explored using GFP fluorescence. Furthermore, it was reported that redox state controls gene transcription or expression, the local presence or synthesis and decomposition of intracellular substances, as well as cell proliferation, differentiation, and cell death.

[0007] The pH level in living organisms is strictly controlled through the regulation of carbon dioxide produced by respiration and metabolism in the kidneys, with a normal range of 7.35–7.45. On the other hand, exhaled hydrogen is hydrogen produced by intestinal bacteria that enters the pulmonary circulation and is then expelled. Devices used to measure the concentration of hydrogen in exhaled breath are Class II medical devices, one of which is the handheld gastrolyser (Bedfont, Kent, UK). It has been noted that the concentration of hydrogen in exhaled breath varies depending on diet or exercise. As shown in Non-Patent Literature 4 below, the hydrogen breath test for diagnosing gastrointestinal diseases is based on the 2017 North American consensus. To eliminate the influence of diet, the test food is ingested after a one-night fast, and the hydrogen concentration in exhaled breath is measured over a period of more than two hours in a resting state. After pulmonary circulation, through gas exchange in the lungs, the hydrogen produced by the digestive tract mixed with venous blood decreases to the alveolar hydrogen partial pressure. This alveolar hydrogen partial pressure is equal to the terminal expiratory hydrogen partial pressure. Hydrogen in the blood is transported from the pulmonary circulation to systemic circulation and diffuses into cells. Hydrogen is an inert gas and is not metabolized; therefore, the partial pressure of hydrogen in tissues is equal to the partial pressure of hydrogen in the final exhalation. The half-saturation time of inert gases (nitrogen) in the body is approximately 30 minutes; therefore, after four times the half-saturation time, or 2 hours, a state of equilibrium is essentially reached (1 - (1 / 2)). 4 =94%).

[0008] Existing technical documents

[0009] Non-patent literature

[0010] Non-patent literature 1: Williamson, DH, Lund, P. & Krebs, HA, The redox state of free nicotinamide-adenine dinucleotide in the cytoplasm and mitochondria of rat liver. The Biochemical journal 103, 514-527 (1967);

[0011] Non-patent literature 2: Jones, D. P, Redox potential of GSH / GSSG couple: assay and biological significance. Methods in enzymology 348, 93-112 (2002);

[0012] Non-patent literature 3: Yuta Hatori, Construction of a gastrointestinal inflammation model and application of intracellular redox sensors, YAKUGAKU ZASSHI 139, 1523-1530 (2019);

[0013] Non-patent literature 4: Rezaie, A. et al., Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus. The American Journal of gastroenterology 112, 775-784 (2017). Summary of the Invention

[0014] Redox status is measured by the ratio or concentration of redox pairs within the cell, or by fluorescence as a form of redox potential. Since the oxidized and reduced states of the same substance cannot be distinguished, the NADH / NAD ratio is determined based on the ratio of metabolites. + The ratio of glutathione to redox potential is used to determine the redox potential. Furthermore, since glutathione forms a dimer in oxidized glutathione disulfide, concentration determination is necessary. While this can be performed in cultured cells to measure the ratio or concentration of metabolites in the cytoplasm and to assess fluorescence, it is difficult to measure the redox potential used to evaluate the redox state in organisms. Direct measurement of redox potential in organisms such as humans has always been challenging; therefore, there is a need to measure the redox potential as an indicator of human health.

[0015] Redox potential can be measured when the redox reaction in a living organism is in equilibrium. The equilibrium state of hydrogen gas and hydrogen ions, one of the redox pairs, is as follows:

[0016] [Chemical Formula 2]

[0017] .

[0018] The standard hydrogen electrode is immersed in a standard pressure P 0 A platinum electrode in a solution with a hydrogen ion activity of 1 mol / L, blown with hydrogen gas at (101.3 kPa). The standard electrode potential E at this point. 0 =0V. The Nernst equation is the equilibrium electrode potential E = E0 corresponding to the electrode reaction. 0 +(RT / nF)ln([Ox] a / [Red] b ):

[0019] [Chemical Formula 3]

[0020]

[0021] (Ox and Red represent the oxidizing and reducing bodies of the redox system, e- represents electrons, and a, b, and n represent the number of molecules or electrons). That is, based on the Nernst formula, the redox potential E at a temperature of 37℃ (310K) is E = 0 - (0.061 / 2) × (log[H2] - 2log[H2]). + Hydrogen ion activity [H] + The logarithm of the reciprocal of ] is pH = -log[H] + Hydrogen gas can be produced at standard pressure P. 0 Even when the pressure is below the standard pressure, hydrogen will dissolve in the aqueous solution according to Henry's Law. Therefore, the hydrogen reactivity [H2] is the hydrogen partial pressure / standard pressure P. 0 Therefore, the hydrogen index, pH2, is defined as the logarithm of the reciprocal of hydrogen activity [H2], i.e., pH2 = -log[H2]. The redox potential E of hydrogen / hydrogen ions becomes E = -0.061 × pH + 0.031 × pH2 (V). The redox potential depends on pH and pH2. The ratio of its potential change is 0.061 V / pH and 0.031 V / pH2.

[0022] In this invention, the partial pressure of hydrogen in the terminal exhalation is measured, and the hydrogen index pH2, which is the logarithm of the reciprocal of the hydrogen partial pressure / standard pressure, is displayed by an instrument. The redox potential E is measured using body temperature 37°C (310K), the normal pH value of the organism 7.4, and the hydrogen index pH2, and is calculated using the formula E = -0.451 + 0.031 × pH2 (V).

[0023] The present invention relates to an in vivo oxidation-reduction potential (ORP) measuring device, which measures ORP in vivo through exhaled hydrogen analysis and displays the results as voltage. The method of the present invention measures ORP in vivo through exhaled hydrogen analysis and displays the results as voltage. The ORP (V) in vivo is determined using the ratio of hydrogen to hydrogen ions. ORP is defined as the ratio of oxidized to reduced form (redox pair) in the equilibrium state of a redox reaction involving electron donation and acceptance. Therefore, the potential of the standard hydrogen electrode is calculated using the Nernst formula related to the equilibrium electrode potential as a reference point of 0V.

[0024] Hydrogen analysis includes a device for measuring the partial pressure of hydrogen in the alveoli during the final exhalation at atmospheric pressure. This is achieved by consistently blowing in a standard pressure P using a standard hydrogen electrode. 0 The state of hydrogen is 1, therefore the hydrogen activity [H2] is proportional to the hydrogen partial pressure (Pa) / 101.3 kPa. The results of hydrogen analysis are expressed by defining the hydrogen index pH2 as the logarithm of the reciprocal of [H2] (pH2 = -log[H2]).

[0025] Furthermore, the in vivo redox potential measured using the in vivo redox potential measuring device and method of the present invention is not an actual measured value, but a value obtained by a prescribed formula. Therefore, in a sense, it is only an estimated value. Thus, the in vivo redox potential verification method of the present invention verifies that the estimated value is approximately similar to the actual in vivo redox potential obtained after measurement.

[0026] According to the present invention, an in vivo redox potential measuring device is provided, which comprises:

[0027] The unit that measures the hydrogen index pH2 of a human subject when the hydrogen index pH2 is defined as the logarithm of the reciprocal of the partial pressure of hydrogen (Pa) / 101.3kPa (pH2=-log[partial pressure of hydrogen / 101.3kPa]).

[0028] A storage unit stores a specified arithmetic expression;

[0029] The processing unit calculates the redox potential using the hydrogen index pH2 measured by the aforementioned hydrogen index measuring unit, and the aforementioned prescribed formula stored in the aforementioned storage unit; and

[0030] The display unit displays the redox potential calculated by the aforementioned arithmetic unit.

[0031] A preferred embodiment is as follows: In the biological in vivo redox potential measuring device of the present invention, as the above-mentioned calculation formula, when E is the redox potential and pH2 is the hydrogen index, E = -0.451 + 0.031 × pH2 (V) is used.

[0032] A preferred embodiment is as follows: In the biological in vivo redox potential measuring device of the present invention, as the above-mentioned calculation formula, when E is the redox potential, pH is the hydrogen ion index of the test subject, and pH2 is the hydrogen index, E = -0.061 × pH + 0.031 × pH2 (V) is used.

[0033] A preferred embodiment is that, in the biological redox potential measuring device of the present invention, the pH value is 7.3 to 7.5.

[0034] A preferred embodiment is that, in the biological redox potential measuring device of the present invention, the pH value is 7.4.

[0035] A preferred embodiment is as follows: In the biological in vivo redox potential measuring device of the present invention, the display unit is configured to display the hydrogen index pH2 measured by the unit for measuring the hydrogen index.

[0036] According to the present invention, a method for measuring redox potential in vivo is provided, the method comprising:

[0037] The procedure for measuring the hydrogen index pH2 of a human subject when the hydrogen index pH2 is defined as the logarithm of the reciprocal of the partial pressure of hydrogen (Pa) / 101.3kPa (pH2=-log[partial pressure of hydrogen / 101.3kPa]);

[0038] The steps to read the specified arithmetic expression stored in the specified memory unit;

[0039] The calculation steps involve using the hydrogen index pH2 measured by the aforementioned hydrogen index measuring unit, and calculating the redox potential using the aforementioned prescribed formula read from the aforementioned storage unit; and

[0040] The display steps show the redox potential calculated through the above calculation steps.

[0041] A preferred embodiment is as follows: In the above-described method for measuring redox potential in vivo according to the present invention, as the above-described formula, when E is the redox potential and pH2 is the hydrogen index, E = -0.451 + 0.031 × pH2 (V) is used.

[0042] A preferred embodiment is as follows: In the above-described method for measuring redox potential in vivo according to the present invention, as the above-described formula, when E is the redox potential, pH is the hydrogen ion index of the test subject, and pH2 is the hydrogen index, E = -0.061 × pH + 0.031 × pH2 (V) is used.

[0043] A preferred embodiment is that, in the above-described method for measuring redox potential in vivo according to the present invention, the pH value is 7.3 to 7.5.

[0044] In the present invention described above, a preferred embodiment is to use a pH value of 7.4.

[0045] A preferred embodiment is as follows: In the above-described method for measuring redox potential in vivo according to the present invention, the display step is configured to display the hydrogen index pH2 measured by the above-described step of measuring the hydrogen index.

[0046] According to the present invention, a method for verifying in vivo redox potential is provided. This method verifies that the in vivo redox potential calculated using the measured hydrogen index pH2 and a prescribed formula approximates the actual in vivo redox potential when the hydrogen index pH2 is defined as the logarithm of the reciprocal of the partial pressure of hydrogen (Pa) / 101.3 kPa (pH2 = -log[partial pressure of hydrogen / 101.3 kPa]). The method comprises the following steps:

[0047] Step 1: Fill the container that constitutes the foaming device with phosphate buffer;

[0048] Step 2: Measure the pH and redox potential (ORP) of the phosphate buffer solution in the container.

[0049] Step 3: Deliver medical air to the above-mentioned bubbling device at a first specified flow rate for a first specified time;

[0050] Step 4: After the gas supply is completed within the specified time, measure the pH and redox potential (ORP) of the phosphate buffer solution in the container again.

[0051] Step 5: Correct the oxidation-reduction potential (ORP) measured after the medical air is supplied using the ORP measured before the medical air is supplied.

[0052] Step 6: Drain the phosphate buffer from the container and fill the container with new phosphate buffer.

[0053] Step 7: Measure the pH and redox potential (ORP) of the new phosphate buffer solution in the container.

[0054] Step 8: For a second specified time, a standard gas containing a specified concentration of hydrogen is supplied to the above-mentioned bubbling device at a second specified flow rate;

[0055] Step 9: After the gas supply is completed at the time specified in step 2 above, measure the pH and redox potential (ORP) of the new phosphate buffer solution in the container again.

[0056] Step 10: Correct the redox potential (ORP) measured after the supply of the standard gas containing the specified concentration of hydrogen using the ORP measured before the supply of the standard gas containing the specified concentration of hydrogen; and

[0057] Step 11: Using the two corrected oxidation-reduction potentials (ORPs) obtained in the above two correction steps, pH2 is set to 6.2 when it is medical air and pH2 is set to 4 when it is a standard gas containing a specified concentration of hydrogen, and the change scheme of the oxidation-reduction potentials (ORPs) relative to the change of pH2 is determined.

[0058] A preferred embodiment is as follows: In the above-described method for verifying redox potential in vivo according to the present invention, steps 1 to 5 are repeated multiple times, and the average value of the multiple measurement results is used. Similarly, steps 6 to 10 are repeated multiple times, and the average value of the multiple measurement results is used.

[0059] Organisms receive signals from the external environment, such as changes in temperature, nutrients, and oxygen. Additionally, they receive endogenous signals, such as relative hypoxia or insufficient glucose as a substrate, based on changes in metabolic requirements, to control cellular function and maintain homeostasis. One such signal is oxidative stress, which includes reactive oxygen species. Organisms possess reduction systems such as glutathione and thioredoxin, which receive energy from NADH or NADPH to maintain homeostasis. This redox state is referred to as the redox state and is measured as the redox potential. The redox potential is defined by its respective redox pairs. Glutathione, one of these pairs, has an intracellular concentration of 3-10 mM and acts as a buffer due to its abundant presence. NADH, on the other hand, has a concentration of 97-168 μM and is constantly reused between the TCA cycle and the electron transport system. Therefore, when these redox pairs are used as indicators, changes in the redox potential are not readily apparent; unless there are significant changes in the metabolic state of cultured cells, such as proliferation, differentiation, or apoptosis, the potential remains unchanged.

[0060] In this invention, the redox potential of hydrogen / hydrogen ions, one of the indicators of redox state, is used to evaluate the redox state in organisms. The hydrogen ion concentration in organisms is 40 nM at pH=7. A hydrogen concentration of 13 ppm in a breath test (6-20 ppm on an empty stomach in the morning) corresponds to a hydrogen solubility of 1282 L × atm / mol in the body, which is approximately 10 nM. That is, less than one part per million of glutathione and less than one part per thousand of NADH. In the cations of blood under acid-base balance, the hydrogen ion concentration is as low as 40 nM, which is one part per million of the sodium ion concentration (130 mEq / L), and its changes are highly sensitive. This suggests that changes in the redox potential based on hydrogen / hydrogen ions, as an indicator of redox balance, are 1000 to 100000 times more sensitive than those based on glutathione or NADH.

[0061] According to the present invention, short-term changes in metabolic state can be obtained more sensitively. Until now, only long-term changes such as cell proliferation, differentiation, and cell death could be obtained. With a sensitive, repeatable indicator, changes in external environmental or endogenous metabolic requirements can be obtained. For example, changes can be observed in hydrogen breath tests based on fasting versus diet and rest versus exercise. Furthermore, since the partial pressure of hydrogen in the body reaches equilibrium in approximately 2 hours, the redox potential in the body can be used as an indicator to measure the effects of diseases or therapeutic agents. Therefore, it is believed that if redox potential can be measured, it can be applied not only to the evaluation of environmental or metabolic states but also to the evaluation of diseases or the development of treatment methods. Attached Figure Description

[0062] [ Figure 1 This is a block diagram showing a preferred embodiment of the bio-oxidation-reduction potential measuring device of the present invention.

[0063] [ Figure 2 [ ] is a block diagram showing a preferred embodiment of the system used for verifying redox potential in vivo according to the present invention.

[0064] [ Figure 3 [ ] is a graph used to illustrate the in vivo redox potential verification method of the present invention. Detailed Implementation

[0065] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0066] Figure 1 This is a block diagram illustrating a preferred embodiment of the bio-based redox potential measuring device of the present invention. A preferred embodiment of the bio-based redox potential measuring method of the present invention is also described below. Figure 1 Please provide an explanation.

[0067] In this invention, although the redox potential of a human being being tested is measured, it is difficult to directly measure the redox potential in organisms such as blood, internal organs, or muscles due to resistance. Therefore, the exhaled breath of the test subject is used in this invention. The pH2 measuring unit 10 measures the hydrogen index pH2 in the exhaled breath by the subject exhaling. As the pH2 measuring unit 10, a semiconductor hydrogen concentration meter can be used, that is, an instrument that detects the change in resistance value generated when a heated metal oxide semiconductor comes into contact with hydrogen gas as the hydrogen concentration, such as the SG8541 from Riken Keiki Co., Ltd. The output signal of the pH2 measuring unit 10, representing the measured hydrogen index pH2, is transmitted to the calculation / control unit 14. A predetermined calculation formula is pre-stored in the storage unit 16, and the calculation result in the calculation / control unit 14 is stored as needed. The input unit 12 is used to give an instruction to the calculation / control unit 14 to start the calculation, or to set the value of the hydrogen ion index pH, which will be described later, in the calculation / control unit 14.

[0068] The redox potential within the organism, calculated by the arithmetic / control unit 14, is transmitted to the display unit 18 and displayed as a numerical value. It should be noted that the input unit 12, arithmetic / control unit 14, storage unit 16, and display unit 18 can also be composed of a personal computer's keyboard and mouse, central processing unit (CPU), memory (RAM, ROM), and display. In this case, in order to supply the output signal of the pH2 measuring unit 10 to the personal computer's USB input unit in an appropriate form, an interface (not shown) is used as needed. In addition to displaying the redox potential within the organism, the display unit 18 also displays the measured hydrogen index pH2. It should be noted that, in addition to the above calculations, the arithmetic / control unit 14 can also control the storage unit 16 or the display unit 18 according to instructions from the device operator input through the input unit 12.

[0069] The storage unit 16 stores a formula for calculating the redox potential E in a biological organism. The basic formula is E = -0.061 × pH + 0.031 × pH² (V). Here, as mentioned above, the pH is 7.35 to 7.45, so an appropriate value within this range can be input to the calculation unit via the input unit 12. On the other hand, since the pH range is only 7.35 to 7.45, it can also be fixed at, for example, 7.4. Therefore, 7.4 can be input as pH via the input unit 12, or 7.4 can be pre-stored in the storage unit 16 for use. However, since 7.4 has been programmed as pH, the basic formula can be simplified to E = -0.451 + 0.031 × pH² (V). Therefore, when the pH is fixed at 7.4, the simplified formula E = -0.451 + 0.031 × pH² (V) can be pre-stored in the storage unit 16 instead of the basic formula. It should be noted that the basic and simplified arithmetic expressions mentioned above can also be pre-stored in the storage unit 16, and either arithmetic expression can be read out and provided to the arithmetic unit 14 as needed, according to the instructions from the input unit 12.

[0070] Next, several practical examples of redox potentials measured using the simplified formula described above are given.

[0071] Measurement conditions and subjects, etc.

[0072] Measurement date and time: September 26, 2018, 8:00 AM to 9:00 AM;

[0073] Case 1: 23-year-old female, had eaten breakfast, hydrogen partial pressure 0.1 Pa, hydrogen index pH2=6.0, redox potential E=-0.265V.

[0074] Case 2: A 44-year-old male who had not eaten breakfast, with a hydrogen partial pressure of 1.9 Pa, a hydrogen index pH of 4.72, and a redox potential E of -0.305 V.

[0075] Case 3: A 34-year-old female who ate breakfast, with a hydrogen partial pressure of 4.6 Pa, a hydrogen index pH of 4.34, and a redox potential E of -0.317 V.

[0076] The table below shows the test results for a total of 10 cases, including cases 1-3 mentioned above.

[0077] [Table 1]

[0078]

[0079] Next, a preferred embodiment of the system used for verifying redox potential in vivo according to the present invention will be described.

[0080] Figure 2 This is a block diagram illustrating a preferred embodiment of the system used for verifying the in vivo redox potential of the present invention. The system includes: a medical air source 20, a hydrogen source 22, two flow meters 24 and 26, a switching valve 28, a bubbling device 30, a pH and redox potential measuring device 36 disposed within a container 31 constituting the bubbling device 30, an interface 40, a display unit 42, and a storage unit 44. The bubbling device 30 utilizes a device typically used as an air humidifier to introduce externally supplied gas into the container 31 via a conduit 32, causing the introduced gas to bubble (aerate) in the liquid within the container 31, and then discharging it to the outside from the upper space of the container 31 via a discharge pipe 34.

[0081] Medical air source 20 delivers medical air after depressurizing it to 200 kPa. Hydrogen source 22 delivers air (standard gas) containing 10 Pa of hydrogen. The depressurized medical air from medical air source 20 and the hydrogen-containing air from hydrogen source 22 are supplied to the bubbling device 30 via flow meters 24 and 26, respectively, selected by switching valve 28. The bubbling device 30 is a device typically used as an air humidifier, and phosphate buffer (10 mM, pH 7.1) 46 can be added to its container 31. For example, PBS (-) manufactured by Fujifilm and Koujun Pharmaceutical Co., Ltd. can be used as the phosphate buffer. Figure 2 A preferred embodiment of the method for verifying redox potential in vivo according to the present invention will be described.

[0082] Phosphate buffer (10 mM, pH 7.1) 46 is placed in container 31, which constitutes the bubbling device 30. The pH and ORP of the phosphate buffer in container 31 are measured using pH and ORP measuring device 36. For example, pH6600 and ORP-6600S manufactured by CUSTOM Corporation can be used as pH and ORP measuring devices 36. The output signal of pH and ORP measuring device 36 is provided to display unit 42 and storage unit 44 via signal transmission path 38 and interface 40. If the pH and ORP are measured and stored in storage unit 44, switching valve 28 is operated to supply medical air to bubbling device 30 at a first predetermined flow rate for a first predetermined time. Here, the first predetermined flow rate is set to 0.5 L / min, and the first predetermined time is set to 1 hour. For example, medical air manufactured by AIR WATER Corporation (containing 0.6 ppm hydrogen, the same as atmospheric air) can be used as medical air.

[0083] After the first predetermined air supply period ends, the pH and ORP of the phosphate buffer solution in container 31 are measured again using pH and ORP measuring device 36, and the measured potentials are stored in storage unit 44. Next, the ORP measured after the medical air supply is corrected using the ORP measured before the medical air supply. For example, if the ORP measured before the medical air supply is 230 mV, this potential is used as a reference of 0 mV. That is, if the ORP measured after the medical air supply is 243 mV, 230 mV is subtracted from this value, correcting 243 mV to 13 mV.

[0084] The phosphate buffer in container 31 is drained, and fresh phosphate buffer is added to container 31. The pH and redox potential (ORP) of the fresh phosphate buffer in container 31 are measured in the same manner as described above. After the measurement and storage of the measured values, a standard gas containing a specified concentration of hydrogen is supplied to the bubbling device 30 at a specified flow rate for a second specified time. Here, the second specified flow rate is set to 0.5 L / min, and the second specified time is set to 1 hour. Furthermore, the specified concentration is, for example, 100 ppm, and a standard gas manufactured by AIR WATER Corporation can be used, for example.

[0085] After the second specified time of gas delivery, the pH and ORP of the new phosphate buffer solution in container 31 are measured again using pH and ORP measuring device 36 and stored. The ORP measured after the delivery of the standard gas containing the specified concentration of hydrogen is corrected using the ORP measured before delivery of the standard gas containing the specified concentration of hydrogen. Here, if the measured potential is 174 mV, then 230 mV is subtracted as described above, and the corrected potential is -56 mV.

[0086] Using the corrected two redox potentials (ORPs) obtained through this operation, with a pH of 6.2 for medical air and a pH of 4 for a standard gas containing a specified concentration of hydrogen, the scheme for determining the change in ORP relative to pH2 is established. That is, as follows... Figure 3 As shown in the curve, since the redox potential (ORP) is -56 mV at pH 2 (4) and 13 mV at pH 2 (6.2), a line segment connecting these points is used to construct... Figure 3 The curves show the pH changes: 0.007 ± 0.021 when air is bubbled and 0.060 ± 0.008 with standard hydrogen gas (10 Pa). Additionally, the redox potential changes: 13.3 ± 17.6 mV after air is bubbled and -56.0 ± 13.5 mV with standard hydrogen gas.

[0087] Based on the above measurements Figure 3 The graph was created based on a single measurement. To reduce measurement error, it is preferable to measure the potential multiple times (e.g., more than three times) and take the average value of the measurement results. Figure 3 In the curves, the upper and lower extensions of the line segments representing the potentials at pH 2 of 4 and pH 2 of 6.2 represent the standard deviations, respectively. The linear regression line is significant (y = -180.8 + 32.2 × pH 2, r). 2 =0.83, p=0.011). Since it is a phosphate buffer, the pH is 7.1 and the change after foaming is less than 0.1, but the redox potential (ORP) changes by 32 mV / pH² due to the partial pressure of hydrogen in the foaming air, consistent with the Nernst equation. Therefore, when the pH is constant, the redox potential is proportional to the pH² of the partial pressure of hydrogen in the foaming air.

[0088] If we explore this point further, then in the formula for y above, r 2 The coefficient of determination is used to evaluate the degree of consistency among the values ​​obtained through regression. The coefficient of determination r... 2 Typically, the value is taken in the range of 0 to 1; a larger value better reflects the data. Next, consider the probability (irrelevant) that the regression coefficient (slope of the line) is 0. The probability of a zero regression coefficient is represented by p. Since this p is less than the significance level of 0.05, it indicates that the change in potential is proportional to the hydrogen index pH2. The coefficient of determination r... 2 The value indicates how well the regression line matches the data, and p represents the probability that the regression coefficient is 0. Since it is less than the significance level of 5%, it is judged to be statistically significant.

[0089] Industrial practicality

[0090] According to the apparatus and method for measuring in vivo redox potential of the present invention, the hydrogen index pH2 of human exhaled breath can be measured, and the measured value can be used to infer the in vivo redox potential, which is difficult to measure directly. Therefore, the health status of visiting patients, hospitalized patients, and other people undergoing health diagnosis can be easily assessed. This method can be applied not only to the evaluation of environmental or metabolic states but also to the evaluation of diseases and the development of treatment methods. Therefore, it can be used in the diagnostic / therapeutic industry for health diagnosis and the treatment of various diseases. Furthermore, according to the method for verifying in vivo redox potential of the present invention, using standard gases and phosphate buffer, the redox potential measured by the apparatus and method described above can be easily verified to be approximately similar to the actual potential. Therefore, it can also be used in the diagnostic / therapeutic industry.

Claims

1. An in vivo redox potential measuring apparatus, comprising: a unit that measures a hydrogen index pH2 of a subject of a person to be measured, the hydrogen index pH2 being defined as a logarithm of a reciprocal of a hydrogen partial pressure / 101.3 kPa, i.e., pH2 = -log [hydrogen partial pressure / 101.3 kPa]; a storage unit that stores a prescribed operation formula; an operation unit that operates a redox potential by the prescribed operation formula stored in the storage unit using the hydrogen index pH2 measured by the unit that measures the hydrogen index; and a display unit that displays the redox potential operated by the operation unit, the unit of the hydrogen partial pressure being Pa. As the operation formula, E = -0.451 + 0.031 x pH2 is used when E is the redox potential and pH2 is the hydrogen index, the unit of E being V. As the operation formula, E = -0.061 x pH + 0.031 x pH2 is used when E is the redox potential, pH is the hydrogen ion index of the subject, and pH2 is the hydrogen index, the unit of E being V.

2. The in vivo oxidation-reduction potential measuring apparatus according to claim 1, characterized by: As the pH, a value of 7.3 to 7.5 is used.

3. The in vivo oxidation-reduction potential measuring apparatus according to claim 1, wherein: As the pH, a value of 7.4 is used.

4. The in vivo oxidation-reduction potential measuring apparatus according to claim 3, wherein: The display unit is configured to display the hydrogen index pH2 measured by the unit that measures the hydrogen index.

5. The in vivo oxidation-reduction potential measurement device of claim 4, wherein:

7. An in vivo redox potential measuring method, comprising:

6. The in vivo oxidation-reduction potential measuring apparatus according to claim 1, wherein: a step of measuring a hydrogen index pH2 of a subject of a person to be measured, the hydrogen index pH2 being defined as a logarithm of a reciprocal of a hydrogen partial pressure / 101.3 kPa, i.e., pH2 = -log [hydrogen partial pressure / 101.3 kPa]; a step of reading out a prescribed operation formula stored in a prescribed storage unit; an operation step of operating a redox potential by the prescribed operation formula read out from the storage unit using the hydrogen index pH2 measured by the step of measuring the hydrogen index; and a display step of displaying the redox potential operated by the operation step, the unit of the hydrogen partial pressure being Pa. As the operation formula, E = -0.451 + 0.031 x pH2 is used when E is the redox potential and pH2 is the hydrogen index, the unit of E being V. As the operation formula, E = -0.061 x pH + 0.031 x pH2 is used when E is the redox potential, pH is the hydrogen ion index of the subject, and pH2 is the hydrogen index, the unit of E being V. As the pH, a value of 7.3 to 7.5 is used.

8. The method for measuring the oxidation-reduction potential in a living organism according to claim 7, characterized by: As the pH, a value of 7.4 is used.

9. The method according to claim 7, wherein the biological ORP is measured in vivo. The display step is configured to display the hydrogen index pH2 measured by the step of measuring the hydrogen index.

10. The method for measuring the oxidation-reduction potential in a living organism according to claim 9, characterized by: ​ 11. The method for measuring the oxidation-reduction potential in a living organism according to claim 10, characterized by: ​ 12. The method according to claim 7, wherein the biological ORP measurement method is characterized by: ​ 13. A method for verifying an in-vivo oxidation-reduction potential, which is a method for verifying that an in-vivo oxidation-reduction potential calculated from a measured hydrogen gas index pH2 and a prescribed calculation formula is approximate to an actual in-vivo oxidation-reduction potential when the hydrogen gas index pH2 is defined as a logarithm of an inverse of a hydrogen partial pressure / 101.3 kPa, i.e., pH2 = -log [hydrogen partial pressure / 101.3 kPa], comprising the following steps: Step 1, charging a phosphoric acid buffer into a container constituting a bubbling device; Step 2, measuring a pH and an oxidation-reduction potential ORP of the phosphoric acid buffer in the container; Step 3, supplying medical air at a first prescribed flow rate to the bubbling device for a first prescribed time; Step 4, measuring again the pH and the oxidation-reduction potential ORP of the phosphoric acid buffer in the container after the supply of the medical air for the prescribed time; Step 5, correcting the oxidation-reduction potential ORP measured after the supply of the medical air using the oxidation-reduction potential ORP measured before the supply of the medical air; Step 6, discharging the phosphoric acid buffer in the container and charging a new phosphoric acid buffer into the container; Step 7, measuring the pH and the oxidation-reduction potential ORP of the new phosphoric acid buffer in the container; Step 8, supplying a standard gas containing a prescribed concentration of hydrogen at a second prescribed flow rate to the bubbling device for a second prescribed time; Step 9, measuring again the pH and the oxidation-reduction potential ORP of the new phosphoric acid buffer in the container after the supply of the standard gas containing the prescribed concentration of hydrogen for the second prescribed time; Step 10, correcting the oxidation-reduction potential ORP measured after the supply of the standard gas containing the prescribed concentration of hydrogen using the oxidation-reduction potential ORP measured before the supply of the standard gas containing the prescribed concentration of hydrogen; and Step 11, grasping a change pattern of the oxidation-reduction potential ORP with respect to a change in pH2, when the pH2 is set to 6.2 for the medical air and when the pH2 is set to 4 for the standard gas containing the prescribed concentration of hydrogen, using the corrected oxidation-reduction potentials ORP obtained in the two correction steps. The unit of the hydrogen partial pressure is Pa. The steps 1 to 5 are repeated a plurality of times, and an average of the measured results is used. The steps 6 to 10 are also repeated a plurality of times, and an average of the measured results is used. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 14. The method of claim 13, wherein the method is used in vivo. ​

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