Intravascular plasma index measurement system

Abstract

This intravascular plasma index measurement system comprises: a first irradiation means for irradiating a living body with first light; a first light receiving means for receiving the first light illuminated by the first irradiation means and transmitted or reflected by the living body; a first calculation means for calculating a measurement value C with respect to the amplitude of the first light over T1 seconds, which is longer than the heartbeat cycle of the living body, on the basis of the first light received by the first light receiving means; a second calculation means for calculating an average value AV with respect to the amplitude of the first light over T2 seconds, which is longer than the T1 seconds, on the basis of the first light received by the first light receiving means; and a third calculation means for calculating an intravascular plasma index M with respect to plasma in the blood vessels of the living body on the basis of the measurement value C calculated by the first calculation means and the average value CAV calculated by the second calculation means.

Description

Intravascular Plasma Index Measurement System

[0001] The present invention relates to an intravascular plasma index measurement system that can non-invasively, easily, and accurately measure the ratio of plasma to blood in a blood vessel (hereinafter referred to as the plasma ratio), and calculates an intravascular plasma index, which serves as an indicator of dehydration, based on the plasma ratio.

[0002] There have been numerous accidents caused by dehydration for a long time. Replenishing fluids is essential for maintaining human life. Generally, hydration is voluntary, not only in humans, but in all living organisms, based on the subjective symptom of "thirst" caused by a lack of blood plasma and its main component, water, in the bloodstream, resulting in a decrease in the amount of fluid delivered to the body by blood. However, if the organism is in a state of tension or excitement, this awareness may be weakened, which is particularly likely to lead to dehydration accidents in the hot sun. Furthermore, as people age, their sense of lack of fluid becomes duller, and they do not take the voluntary action of replenishing water, leading to frequent accidents caused by dehydration.

[0003] Furthermore, a decrease in fluid in the blood vessels can cause blood clots in the blood vessels, leading to serious symptoms. It is generally said that losing more than 2-3% of body weight in fluid (1.2-1.8 liters for a 60 kg person) can be life-threatening.

[0004] For these reasons, there is a need for a blood moisture content detection device such as that shown in Patent Document 1. Patent Document 1 discloses a blood moisture content detection device that removes noise due to low frequency components caused by fluctuations associated with autonomic nervous activity from a pulse wave detected by a pulse wave detection unit and calculates an index that varies depending on the blood moisture content. Patent Document 2 also discloses a device that measures biological information by irradiating a living body with multiple wavelengths and using the amount of transmitted or reflected light to obtain the moisture content of the skin, etc.

[0005] International Publication No. WO2004 / 006769 Japanese Patent Application Laid-Open No. 2019-130070

[0006] In general, pulse wave waveforms are significantly affected by weight and individual differences. In addition, if there is arrhythmia or if the pulse wave detector detects noise caused by vibrations during walking that occur at roughly the same rhythm as the pulse, it is difficult to remove this noise.

[0007] In particular, in Patent Document 1, the detected pulse wave is differentiated on the time axis, so the high-order frequency components contained in arrhythmia, walking, etc. are calculated as large values, making it impossible to accurately calculate the amount of water and preventing the detection of trends toward dehydration.

[0008] Furthermore, Patent Document 2 only detects the moisture content of the skin, and does not disclose any suggestion of detecting the amount of blood plasma in the blood vessels. Since moisture in the skin does not lead to improvement of dehydration symptoms, there is a problem in that it is not possible to detect the tendency toward dehydration symptoms.

[0009] Therefore, the present invention has been developed to solve the above-mentioned problems, and its purpose is to provide an intravascular plasma index measurement system that can accurately detect the intravascular plasma index, which is an indicator of the lack of water required in the body, even when the pulse wave fluctuates greatly due to the influence of noise caused by disturbances such as arrhythmia or walking, or when there is a lot of water on the skin due to sweating or in cells due to swelling.

[0010] The intravascular plasma index measurement system according to the first invention includes a first irradiating means for irradiating a living body with a first light, a first light receiving means for receiving the first light irradiated by the first irradiating means and transmitted or reflected by the living body, and a T that is longer than the heartbeat period of the living body based on the first light received by the first light receiving means. １ a first calculation means for calculating a measurement value C relating to the amplitude of the first light for a period of time, and a first light receiving means for receiving the first light based on the measurement value C. １ T longer than seconds ２ Average value C for the amplitude of the first light per second ＡＶ a second calculation means for calculating the measured value C calculated by the first calculation means and the average value C calculated by the second calculation means; ＡＶ The present invention is characterized by comprising a third calculation means for calculating an intravascular plasma index M relating to the blood plasma in the blood vessels of the living body based on the above.

[0011] The intravascular plasma index measurement system according to the second invention is characterized in that, in the first invention, the third calculation means calculates the intravascular plasma index M using the following equation (1):

[0012] M = K (C - C ＡＶ ) ｎ +L (1) where K, L, and n are constants.

[0013] The intravascular plasma index measurement system according to the third invention is characterized in that, in the first invention, the intravascular plasma index M is calculated using the following equation (2):

[0014] M = f(C - C ＡＶ ) (2) Here, f(x) is a function such that the differential value obtained by differentiating f(x) with respect to x when x is equal to or greater than the constant g is smaller than the differential value when x is smaller than the constant g.

[0015] The intravascular plasma index measurement system according to a fourth aspect of the present invention is the system of the first aspect of the present invention, wherein the first calculation means calculates an AC value A indicating the amplitude of the first light based on the first light received by the first light receiving means. １ and a DC value D based on the intensity of the first light. １ and the extracted AC value A １ and DC value D １ The measurement value C is calculated based on the above.

[0016] The intravascular plasma index measurement system according to the fifth invention is characterized in that, in the fourth invention, the third calculation means calculates the intravascular plasma index M using the following equation (3):

[0017] M = K (C - C ＡＶ ) ｎ +L (3) where K, L, and n are constants, and C = A １ / D １ Let's say.

[0018] The intravascular plasma index measurement system according to the sixth invention is characterized in that, in the fourth invention, the third calculation means calculates the intravascular plasma index M using the following equation (4):

[0019] M = f(C - CＡＶ ) (4) Here, f(x) is a function such that the differential value obtained by differentiating f(x) with respect to x when x is equal to or greater than the constant g is smaller than the differential value when x is smaller than the constant g.

[0020] The intravascular plasma index measurement system according to the seventh aspect of the present invention includes a first irradiating means for irradiating a living body with a first light, a first light receiving means for receiving the first light irradiated by the first irradiating means and transmitted or reflected by the living body, and an AC value A indicating the amplitude of the first light based on the first light received by the first light receiving means. １ and a DC value D based on the intensity of the first light. １ a second irradiating means for irradiating the living body with second light having a wavelength shorter than that of the first light and having a wavelength at which water has a smaller absorption characteristic than that of the first light; a second light receiving means for receiving the second light irradiated by the second irradiating means and transmitted through or reflected by the living body; and an AC value A indicating the amplitude of the second light based on the second light received by the second light receiving means. ２ and a DC value D based on the intensity of the second light. ２ and a second calculation means for extracting the AC value A calculated by the first calculation means and the second calculation means. １ and AC value A ２ and DC value D １ and DC value D ２ and a third calculation means for calculating an intravascular plasma index M relating to the blood plasma in the blood vessels of the living body based on the above.

[0021] The intravascular plasma index measurement system according to the eighth invention is characterized in that, in the seventh invention, the third calculation means calculates the intravascular plasma index M using the following equations (5) and (6):

[0022] C = (A １ / D １ ) / (A ２ / D ２ ) (5) M=K(C-C ＡＶ ) ｎ +L (6) where K, C ＡＶ , L, and n are constants.

[0023] The intravascular plasma index measurement system according to the ninth invention is characterized in that, in the seventh invention, the third calculation means calculates the intravascular plasma index M using the following equations (7) and (8):

[0024] C = (A １ / D １ ) / (A ２ / D ２ ) (7) M=K(C-C ＡＶ ) ｎ +L (8) where K, L, and n are constants, and C ＡＶ is (A １ / D １ ) / (A ２ / D ２ ) is the average value.

[0025] The intravascular plasma index measurement system according to the tenth invention is characterized in that, in the seventh invention, the third calculation means calculates the intravascular plasma index M using the following equations (9) and (10):

[0026] C = (A １ / D １ ) / (A ２ / D ２ ) (9) M=f(CC ＡＶ ) (10) where f(x) is a function whose differential value when x is equal to or greater than the constant g is smaller than the differential value when x is smaller than the constant g, and C ＡＶ is (A １ / D １ ) / (A ２ / D ２ ) or a constant.

[0027] The intravascular plasma index measurement system according to the eleventh invention is characterized in that, in the first invention, the wavelength of the first light has a wavelength included in any one of 960 nm to 980 nm, 1440 nm to 1460 nm, and 1930 nm to 1950 nm.

[0028] The intravascular plasma index measurement system according to the twelfth invention is the seventh invention, characterized in that the wavelength of the first light is any of 960 nm to 980 nm, 1440 nm to 1460 nm, and 1930 nm to 1950 nm, and the second light has a wavelength of 800 nm or less.

[0029] The intravascular plasma index measurement system according to the thirteenth invention is characterized in that, in the first invention, it further comprises one or more of a display means for displaying the intravascular plasma index M calculated by the third calculation means, a vibration means for generating vibrations based on the intravascular plasma index M calculated by the third calculation means, a communication means for communicating the intravascular plasma index M calculated by the third calculation means to an external device, and a sound means for generating sound based on the intravascular plasma index M calculated by the third calculation means.

[0030] The intravascular plasma index measurement system according to the fourteenth invention is characterized in that, in the first invention, it further comprises an acquisition means for acquiring temperature information relating to temperature, and a determination means for determining abnormality of the living body based on the temperature information acquired by the acquisition means and the intravascular plasma index M calculated by the third calculation means.

[0031] The intravascular plasma index measurement system of the fifteenth invention is characterized in that, in the first invention, it further comprises an acquisition means for acquiring oxygen information relating to the blood saturated oxygen concentration of the living body, and a determination means for determining abnormalities in the living body based on the oxygen information acquired by the acquisition means and the intravascular plasma index M calculated by the third calculation means.

[0032] The intravascular plasma index measurement system according to the 16th invention is characterized in that, in the first invention, the first light receiving means receives a first extraneous light different from the first light, and the first calculation means corrects the measurement value C based on the first extraneous light received by the first light receiving means.

[0033] The intravascular plasma index measurement system according to a seventeenth aspect of the present invention is the system of the seventh aspect of the present invention, wherein the first light receiving means receives first extraneous light different from the first light, and the first calculation means calculates the AC value A based on the first extraneous light received by the first light receiving means.１ and the DC value D １ and the second light receiving means receives second extraneous light different from the second light, and the second calculation means calculates the AC value A based on the second extraneous light received by the second light receiving means. ２ and the DC value D ２ and

[0034] The intravascular plasma index measurement system according to the eighteenth invention is characterized in that, in the first invention, it further comprises an acquisition means for acquiring pulse information relating to the pulse rate of the living body, and a determination means for determining abnormality of the living body based on the pulse information acquired by the acquisition means and the intravascular plasma index M calculated by the third calculation means.

[0035] The intravascular plasma index measurement system of the 19th invention is characterized in that, in the first invention, it further comprises an acquisition means for acquiring one or more of temperature information related to temperature, oxygen information related to the blood saturated oxygen concentration of the living body, and pulse information related to the pulse rate of the living body, and a determination means for determining the type of water to be prescribed to the living body based on one or more of the temperature information, oxygen information, and pulse information acquired by the acquisition means and the intravascular plasma index M calculated by the third calculation means.

[0036] The intravascular plasma index measurement system according to a twentieth aspect of the present invention is the eighth aspect, wherein the third calculation means acquires attribute information relating to attributes of the living body, and calculates the C based on the acquired attribute information. ＡＶ The feature is that the following is set:

[0037] According to the first to twentieth inventions, the measured value C and the average value or constant C of the measured values ​​C for several minutes or more ＡＶ In a blood pulse with less plasma than normal, the amplitude of the light signal at a wavelength that is absorbed by water, the main component of plasma, decreases, but the amplitude of the light signal at a wavelength that is not absorbed by water in the plasma remains unchanged. For this reason, for example, the measured value C and the average value or constant C ＡＶBy calculating the ratio or difference between the measured value C and the measured value T, it is possible to detect the intravascular plasma index M. １ This makes it possible to detect the intravascular plasma index M with high accuracy even when the pulse wave fluctuates greatly due to the influence of noise caused by disturbances such as arrhythmia or walking.

[0038] According to the first to twentieth inventions, the measured value C and the average value or constant C of C for several minutes or more are ＡＶ Based on this, the intravascular plasma index M is calculated without being affected by the moisture on the skin surface or the moisture in the cells. The intravascular plasma index M is the proportion of plasma in the blood vessels. Water is supplied to every corner of the body mainly from the plasma in the blood, and a state of dehydration is equivalent to a state in which there is a deficiency of plasma in the blood vessels. Therefore, by accurately calculating the intravascular plasma index M, it is possible to more accurately notify the user of the state of dehydration and make it easier to convey dangerous situations.

[0039] In particular, according to the second invention, the intravascular plasma index M is calculated using the formula (1). As a result, the measured value C and the average value C ＡＶ When the difference between the measured value C and the average value C is small, the dehydration symptoms are also slight, so the change in the value of the intravascular plasma index M is small. ＡＶ When the difference between the values ​​is large, the change in the value of the intravascular plasma index M can be increased, making it possible to clearly indicate the characteristics of dehydration symptoms, making it easier to inform the user of the dehydration state more accurately and of the dangerous situation.

[0040] In particular, according to the third invention, the third calculation means calculates the intravascular plasma index M using the formula (2). ＡＶ ) is greater than the predetermined value g, the change in the intravascular plasma index M becomes small, and (C - C ＡＶ ) is smaller than the predetermined value g, the change in the intravascular plasma index M becomes large, so that the dehydration state can be more accurately notified to the user, and it becomes easier to inform the user of the dangerous situation.

[0041] In particular, according to the fourth aspect of the present invention, the AC value A １ and DC value D １ Based on this, the measured value C is calculated. １The value of is determined by the increase or decrease in water, which is the main component of blood plasma, due to pulsation. １ The DC value D also varies depending on the condition of the body surface, individual differences such as melanin and fat present other than blood, and the condition of the light path. １ varies depending on the average amount of water contained in the blood plasma, the state of the body surface, individual differences in melanin, fat other than blood, etc., and the state of the light path. １ DC value D １ By dividing by this, it is possible to obtain a measurement value C, which is a dimensionless change in light intensity. This measurement value C is a value corrected for the amount of plasma that is inherent in the living body and is not affected by pulsation, as well as the influence of the state of the body surface and fat present other than blood, and therefore it is possible to detect the intravascular plasma index M with higher accuracy.

[0042] In particular, according to the fifth aspect of the present invention, the third calculation means calculates the intravascular plasma index M using the formula (3). ＡＶ When the difference between the measured value C and the average value C is small, the dehydration symptoms are also slight, so the change in the intravascular plasma index M is small. ＡＶ When the difference between the two increases, the change in the intravascular plasma index M can be increased, making it possible to clearly indicate the characteristics of dehydration symptoms, making it easier to inform the user of the dehydration state more accurately and of the dangerous situation.

[0043] In particular, according to the sixth aspect of the present invention, the third calculation means calculates the intravascular plasma index M using the formula (4). ＡＶ ) is greater than the predetermined value g, the change in the intravascular plasma index M becomes small, and (C - C ＡＶ ) is smaller than the predetermined value g, the change in the intravascular plasma index M will be large, making it easier to inform the user of the dehydration state more accurately and of the dangerous situation.

[0044] In particular, according to the seventh aspect of the present invention, the AC value A １ and AC value A ２ and DC value D １ and DC value D ２ The intravascular plasma index M is calculated based on the AC value A １The value of is determined by the increase or decrease due to the pulsation of water and hemoglobin, which are the main components in the plasma. １ The DC value D varies depending on the condition of the body surface, melanin, and fat present in addition to blood, as well as individual differences and the condition of the light path. １ The AC value A varies depending on the average amount of water and hemoglobin contained in the blood plasma, the condition of the body surface, melanin, individual differences such as fat present other than blood, and the condition of the light path. ２ The value is determined by the increase or decrease due to the pulsation of water and hemoglobin, which are the main components in plasma, but the influence of absorption by water is １ Also, AC value A ２ The DC value D varies depending on the condition of the body surface, melanin, fat present in addition to blood, and other individual differences, as well as the condition of the light path. ２ The effect of water absorption varies depending on the average value of the water content and hemoglobin in the blood plasma, the condition of the body surface, melanin, and fat present in addition to blood, as well as individual differences and the condition of the light path. １ As a result, by calculating the amplitude ratio between the two wavelengths, the influence of extravascular water and the influence of biological tissue can be accurately eliminated, and the intravascular plasma index M can be accurately calculated.

[0045] In particular, according to the eighth aspect of the present invention, the third calculation means calculates the intravascular plasma index M using the formulas (5) and (6). ＡＶ When the difference between the measured value C and the constant C is small, the dehydration symptoms are also slight, so the change in the value of the intravascular plasma index M is small. ＡＶ When the difference between the values ​​is large, the change in the value of the intravascular plasma index M can be displayed in a larger scale, making it possible to clearly show the characteristics of dehydration symptoms, and thus making it easier to inform the user of the dehydration state more accurately and of the dangerous situation.

[0046] In particular, according to the ninth aspect of the present invention, the third calculation means calculates the intravascular plasma index M using the formulas (7) and (8). １ / D １ ) / (A２ / D ２ ) for a specific organism with a large or small value, ＡＶ in the living body (A １ / D １ ) / (A ２ / D ２ ) is used as the average value, it becomes possible to detect the intravascular plasma index M with higher accuracy.

[0047] In particular, according to the tenth aspect of the present invention, the third calculation means calculates the intravascular plasma index M using the formulas (9) and (10). As a result, when the measured value C is larger than the predetermined value, the change in the intravascular plasma index M becomes small, and (C - C ＡＶ ) is smaller than a predetermined value, the change in the intravascular plasma index M becomes large, so that the dehydration state can be more accurately notified to the user, and it becomes easier to inform the user of the dangerous situation.

[0048] In particular, according to the eleventh aspect of the present invention, the wavelength of the first light is any one of 960 nm to 980 nm, 1440 nm to 1460 nm, and 1930 nm to 1950 nm, whereby the wavelength of the first light is near the peak of the absorption coefficient of water, making it possible to detect the intravascular plasma index M with higher accuracy.

[0049] In particular, according to the twelfth aspect of the present invention, the first light has a wavelength included in any one of 960 nm to 980 nm, 1440 nm to 1460 nm, and 1930 nm to 1950 nm, and the second light has a wavelength of 800 nm or less. This increases the difference between the absorption coefficient of water at the wavelength of the first light and the absorption coefficient of water at the wavelength of the second light, making it possible to detect the intravascular plasma index M with higher accuracy.

[0050] In particular, according to the thirteenth aspect of the present invention, the device is provided with one or more of a display means, a vibration means, a communication means, and a sound means, which makes it possible to notify the living body or the user of an abnormality in the living body by, for example, vibration, sound, or image.

[0051] In particular, according to the fourteenth aspect of the present invention, the determining means determines whether or not there is an abnormality in the living body based on the temperature information and the intravascular plasma index M. This makes it possible to determine whether or not there is an abnormality in the living body, taking into consideration, for example, the body temperature of the living body and the outside air temperature.

[0052] In particular, according to the fifteenth aspect of the present invention, abnormalities in the living body are determined based on oxygen information and the intravascular plasma index M. This makes it possible to determine abnormalities in the living body by taking into account, for example, the blood oxygen saturation concentration of the living body. Therefore, even if the measured value C fluctuates due to an abnormality in the saturated oxygen concentration of hemoglobin caused by, for example, pneumonia, accurate determination is possible.

[0053] In particular, according to the sixteenth aspect of the present invention, the first calculation means corrects the measurement value C based on the first extraneous light, thereby making it possible to correct noise due to the influence of extraneous light when the first light is not irradiated, for example, and therefore to detect the intravascular plasma index M with higher accuracy.

[0054] In particular, according to the seventeenth aspect of the present invention, the first calculation means calculates the AC value A based on the first external light. １ and DC value D １ and the second calculation means corrects one or more of the AC value A based on the second extraneous light. ２ and DC value D ２ This makes it possible to correct noise caused by the influence of extraneous light when the first light and the second light are not irradiated, for example, and therefore makes it possible to detect the intravascular plasma index M with higher accuracy.

[0055] In particular, according to the eighteenth aspect of the present invention, an abnormality in the living body is determined based on pulse information and the intravascular plasma index M. This makes it possible to determine an abnormality in the living body by taking into account, for example, the pulse rate of the living body.

[0056] In particular, according to the nineteenth aspect of the present invention, the determining means determines the type of fluid to be prescribed to the living body based on one or more of temperature information, oxygen information, and pulse information, and the intravascular plasma index M. This makes it possible to determine an appropriate oral rehydration solution, etc., depending on the condition of the living body.

[0057] In particular, according to the twentieth aspect of the present invention, the third calculation means calculates, based on the attribute information, ＡＶ This allows for more appropriate C matching the attributes of the living body, such as sex, age, and race. ＡＶTherefore, the intravascular plasma index M can be detected with higher accuracy.

[0058] Fig. 1 is a schematic diagram showing an example of the configuration of an intravascular plasma index measurement system in this embodiment. Fig. 2 is a schematic diagram showing an example of the configuration of a sensor in this embodiment. Fig. 3 is a diagram showing an example of an intravascular plasma index measurement device in this embodiment. Fig. 4 is a diagram showing the function of an intravascular plasma index measurement device incorporating a sensor in this embodiment. Fig. 5 is a flowchart showing an example of the operation of the intravascular plasma index measurement system 100 in this embodiment. Fig. 6(a) shows the DC value D in the first photoelectric data. １ and AC value A １ FIG. 6B is a diagram showing the DC value D ２ and AC value A ２ FIG. 6C is a diagram showing the DC value D in the first photoelectric data when there is a water deficiency. １ and AC value A １ FIG. 6(d) is a diagram showing the DC value D in the second photoelectric data when there is a water deficiency. ２ and AC value A ２ FIG. 7 is a diagram showing the (C-C ＡＶ 8 is a graph showing the intravascular plasma index M versus H ２ 9 is a diagram showing the light absorption coefficient in the blood vessel plasma index measurement system according to the present embodiment. ＡＶ 10 is a flowchart showing the operation after calculating the intravascular plasma index M in the intravascular plasma index measurement system of this embodiment. FIG. 11 is a diagram showing an example of the display unit 12.

[0059] Hereinafter, an example of an intravascular plasma index measurement system according to an embodiment of the present invention will be described with reference to the drawings.

[0060] Figure 1 is a schematic diagram showing an example of the configuration of an intravascular plasma index measurement system 100. For example, as shown in Figure 1, the intravascular plasma index measurement system 100 includes an intravascular plasma index measurement device 2, a server 3, a user terminal 7, and a sensor 1 connected via a public communication network 4. Alternatively, the intravascular plasma index measurement system 100 may include only the intravascular plasma index measurement device 2 with the sensor 1 built in.

[0061] The server 3 is a storage medium that stores various data transmitted from the intravascular plasma index measurement device 2 and the sensor 1. The server 3 also transmits the stored various data as needed to the intravascular plasma index measurement device 2, the sensor 1, and the user terminal 7. The server 3 may have at least some of the functions of the intravascular plasma index measurement device 2, for example, and may perform at least some of the processing instead of the intravascular plasma index measurement device 2, for example.

[0062] The public communication network 4 is, for example, the Internet network to which the intravascular plasma index measurement device 2 is connected via a communication circuit. The public communication network 4 may be configured as a so-called optical fiber communication network. Furthermore, the public communication network 4 may be realized by known communication technologies such as a wired communication network or a wireless communication network. The user terminal 7 is owned, for example, by a user of a service using the intravascular plasma index measurement system 100, and is connected to the intravascular plasma index measurement device 2 via the public communication network 4. The user terminal 7 may represent, for example, an electronic device that generates a database. The user terminal 7 may be, for example, an electronic device such as a personal computer or a tablet terminal. The user terminal 7 may have at least some of the functions of the intravascular plasma index measurement device 2. The user terminal 7 may have a display or speaker (not shown) that can present various information to the user.

[0063] The sensor 1 receives light irradiated onto a living body 6. The sensor 1 is a sensor for obtaining an intravascular plasma index M, which is an index of blood plasma in blood vessels, by pinching, for example, a finger of the living body 6. The sensor 1 has a structure suitable for measurement in which light passes through the living body. As shown in FIG. 2 , the sensor 1 includes an infrared light emitter 31 that emits a first light, which is infrared light, a red light emitter 32 that emits a second light, which is red light, an infrared light receiver 10 that receives the first light, and a red light receiver 11 that receives the second light. The sensor 1 is also arranged so that the infrared light emitter 31 and the red light emitter 32 face the infrared light receiver 10 and the red light receiver 11. The sensor 1 may also be a housing 300 including an upper housing 301 having an infrared light emitter 31 and a red light emitter 32 on its underside, and a lower housing 341 having an infrared light receiver 10 and a red light receiver 11 on its upper side and facing the upper housing 301. The upper housing 301 has an upper recess 302 on its underside, which is recessed upward. The lower housing 341 has a lower recess 342 on its upper side, which is recessed downward. The upper recess 302 and the lower recess 342 are formed so that a finger of the living body 6 can be inserted between them. The upper housing 301 and the lower housing 341 are connected via a shaft 304 and are formed to be rotatable relative to each other. The upper recess 302 and the lower recess 342 are formed so that they open in directions away from each other. A spring (not shown) is provided between the upper housing 301 and the lower housing 341, and applies a negative force in the direction of closing the upper recess 302 and the lower recess 342. The upper housing 301 and the lower housing 341 are formed so that a finger or the like of a living body inserted between the upper recess 302 and the lower recess 342 can be held in a clamped state. The sensor 1 may also be capable of detecting any of temperature information related to the temperature of the environment or the temperature of the living body 6, oxygen information related to the saturated oxygen concentration in the blood of the living body 6, and pulse information related to the pulse rate of the living body 6.

[0064] The intravascular plasma index measurement device 2 is a device that calculates the intravascular plasma index M. The intravascular plasma index measurement device 2 may be, for example, a wristwatch-type device worn on a living body 6 as shown in FIG. 3. The intravascular plasma index measurement device 2 may be, for example, a housing 400 having a display unit 12 such as a monitor on its surface 401a. The intravascular plasma index measurement device 2 may also have, for example, an infrared light emitter 31, a red light emitter 32, an infrared light receiver 10, and a red light receiver 11 on its back surface 401b, and may have a built-in sensor 1. The housing 400 is formed so that the back surface 401b can be attached tightly to the skin of the living body by a wristband 402.

[0065] 4 is a diagram showing the functions of the intravascular plasma index measuring device 2 incorporating the sensor 1. As shown in FIG. 4, the intravascular plasma index measuring device 2 includes a display unit 12, a communication unit 13, a connector 14, a power switch 15, an intravascular plasma index calculation circuit 17, a light emission control circuit 36, an environmental temperature measuring unit 33a, a body temperature calculation circuit 37, a vibration unit 21, a sound generating unit 22, and an SpO ２ The first housing 41 includes a control circuit 18 connected to a measuring unit 23, a battery 19, and a contact sensor 26. The intravascular plasma index measuring device 2 also includes an infrared light receiving unit 10 and a red light receiving unit 11 of the sensor 1 connected to an intravascular plasma index calculation circuit 17. The intravascular plasma index measuring device 2 also includes a red light emitting unit 32 and an infrared light emitting unit 31 of the sensor 1 connected to an emission control circuit 36. The intravascular plasma index measuring device 2 also includes a temperature measuring unit 33 provided with an environmental temperature measuring unit 33a and a differential temperature measuring unit 33b connected to a body temperature calculation circuit 37.

[0066] The infrared light emitter 31 emits the first light, which is infrared light. For example, the infrared light emitter 31 emits infrared light with a wavelength near 970 nm as the first light. The infrared light emitter 31 may also emit light with a wavelength of 1450 nm or 1940 nm, at which the absorption coefficient of water peaks. The infrared light emitter 31 may also emit light with a wavelength included in any of 960 nm to 980 nm, 1440 nm to 1460 nm, and 1930 nm to 1950 nm as the first light. The infrared light emitter 31 may also emit light with a plurality of wavelengths including the above wavelengths.

[0067] The red light emitter 32 emits second light having a wavelength shorter than that of the first light and having a wavelength that is less absorbed by water than that of the first light. The red light emitter 32 emits red light having a wavelength of, for example, 800 nm or less as the second light. The red light emitter 32 emits red light having a wavelength of, for example, around 730 nm as the second light. The red light emitter 32 may also emit light of multiple wavelengths including the above wavelengths.

[0068] Alternatively, the infrared light emitter 31 and the red light emitter 32 may alternately emit the first light and the second light, respectively. The infrared light emitter 31 and the red light emitter 32 may repeatedly emit light for a short period of time, for example, every second.

[0069] The infrared light receiving unit 10 is a light receiving element that receives the first light irradiated from the infrared light emitting unit 31 and transmitted through or reflected by the living body 6, and performs photoelectric conversion. The infrared light receiving unit 10 outputs an electrical signal of the photoelectrically converted first light to the intravascular plasma index calculation circuit 17.

[0070] The red light receiving unit 11 is a light receiving element that receives the second light irradiated from the red light emitting unit 32 and transmitted through or reflected by the living body 6, and performs photoelectric conversion. The red light receiving unit 11 outputs an electrical signal of the photoelectrically converted second light to the intravascular plasma index calculation circuit 17.

[0071] The infrared light receiving unit 10 and the red light receiving unit 11 may be provided with optical filters that receive only light of a specific wavelength. For example, the infrared light receiving unit 10 may be provided with an optical filter that receives only light with a wavelength of 970 nm, and the red light receiving unit 11 may be provided with an optical filter that receives only light with a wavelength of 730 nm. The infrared light receiving unit 10 and the red light receiving unit 11 may also be a single light receiving element that can receive light in the wavelength band of, for example, 400 nm to 1000 nm.

[0072] The display unit 12 is configured with a liquid crystal display, an electronic bulletin board, or the like, and displays various information to the user. The display unit 12 displays, for example, the moisture in vessel index (MOI) of the living body 6, the ambient temperature (Temp.), the body temperature (Body Temp.), the pulse rate (Heart rate), and the saturated oxygen concentration (SpO2) of the living body 6. The types of information displayed by the display unit 12 include various information measured regarding the living body, such as the moisture in vessel index (M), the pulse rate (P), the ambient temperature (Te), and the body temperature (T), but are not limited thereto. The display unit 12 may also display various information such as the current operating status, the remaining battery status (status) of the battery 19, and the communication status. The display unit 12 displays information under the control of the control circuit 18. The display unit 12 is not limited to displaying text, and may also be a single red LED (not shown) that displays a warning when the moisture in vessel index (M) falls below a predetermined value.

[0073] The communication unit 13 performs wireless communication with external devices and various gateway devices. The communication unit 13 communicates with the server 3 and the user terminal 7, for example, via the public communication network 4, and transmits, for example, the calculated intravascular plasma index M. The communication unit 13 has an antenna mounted therein for transmitting and receiving radio waves. The communication unit 13 may also be mounted with a circuit for converting an electrical signal sent from the control circuit 18 into radio waves, or for converting a radio wave received from an external device into an electrical signal and sending it to the control circuit 18. Information output from the communication unit 13 also includes various information displayed on the display unit 12 described above.

[0074] The connector 14 is an interface circuit for performing wired communication with an external device. A wired cable (not shown) is connected to the connector 14, which receives various information from the external device and outputs it to the control circuit 18. The connector 14 also transmits various information input from the control circuit 18 to the external device via the wired cable (not shown).

[0075] The power switch 15 is composed of a button or the like for starting or stopping the power supply of the intravascular plasma index measurement device 2. When the power switch 15 is pressed, a signal transmitted in response to the pressing of the power switch 15 reaches the control circuit 18. When the control circuit 18 receives the signal transmitted in response to the pressing of the power switch 15, it executes control for starting or stopping the power supply of the intravascular plasma index measurement device 2. In addition, the power switch 15 may be configured to start or stop the power supply of the intravascular plasma index measurement device 2 when the sensor 1 detects a living body 6. The power switch 15 may repeatedly emit light for a short period of time, for example, every second, in the infrared light emitting unit 31 or the red light emitting unit 32, and detect the insertion of a living body 6, for example, a finger, based on an increase or decrease in the amount of received light, thereby controlling the start or stop of the power supply.

[0076] The intravascular plasma index calculation circuit 17 receives a signal based on the first light supplied from the infrared light receiving unit 10 and acquires a signal based on the second light supplied from the red light receiving unit 11. The intravascular plasma index calculation circuit 17 has a memory capable of storing data measured multiple times within at least one pulsation cycle of the living body 6. The intravascular plasma index calculation circuit 17 calculates the intravascular plasma index M based on the acquired signal. The intravascular plasma index calculation circuit 17 also retains the calculation results and is capable of storing average values ​​and the like calculated over a long period of use in the memory.

[0077] The intravascular plasma index calculation circuit 17 calculates the intravascular plasma index M of the living body and the pulse rate based on the subject's pulsation using the signal based on the first light and the signal based on the second light. The intravascular plasma index calculation circuit 17 outputs the measured intravascular plasma index M and pulse rate of the living body to the control circuit 18.

[0078] The control circuit 18 is a so-called central control unit for controlling each component in the intravascular plasma index measurement device 2. The control circuit 18 includes a display unit 12, a communication unit 13, a connector 14, an intravascular plasma index calculation circuit 17, a light emission control circuit 36, a vibration unit 21, a sound generation unit 22, and an SpO ２The control circuit 18 controls the measurement unit 23. The control circuit 18 is equipped with a CPU (Central Processing Unit) and also includes memories connected to the CPU. The memories store tables, programs, etc. required to control the hardware resources of the entire intravascular plasma index measurement device 2. The control circuit 18 may also execute the arithmetic processing of the intravascular plasma index calculation circuit 17.

[0079] The battery 19 is a battery for supplying power to the intravascular plasma index measurement device 2 and may be a commercially available button battery or a dry cell battery, but is not limited thereto and may be a rechargeable battery. The battery 19 is stored in a storage pack (not shown) that can accommodate the positive and negative poles of the battery 19. When the power is turned on by the power switch 15, electricity flows through the positive and negative poles to each component implemented in the intravascular plasma index measurement device 2 via the control circuit 18, enabling operation. Note that the power may also be turned on by photoelectrically detecting the living body 6 as described above, without operating the power switch 15.

[0080] The vibration unit 21 generates vibrations under the control of the control circuit 18 when an abnormality is detected in the intravascular plasma index M or the like, and outputs a warning signal to the living body 6 or the user. The vibration unit 21 may have, for example, a vibration function, and may activate the vibration function as a warning signal.

[0081] The sound output unit 22 outputs a warning sound or a warning voice to the living body 6 or the user when an abnormality is detected in the intravascular plasma index M or the like, under the control of the control circuit 18. The sound output unit 22 may have, for example, a speaker, and may present the warning sound or a warning voice via the speaker.

[0082] SpO ２ The measurement unit, under the control of the control circuit 18 , measures oxygen information relating to the saturated oxygen concentration in the blood of the living body 6 by known means, and outputs the measured oxygen information to the control circuit 18 .

[0083] The temperature measurement unit 33 includes an environmental temperature measurement unit 33a and a differential temperature measurement unit 33b. The environmental temperature measurement unit 33a and the differential temperature measurement unit 33b measure temperature information related to temperature. The environmental temperature measurement unit 33a measures environmental temperature information related to the environmental temperature Te, for example, the temperature of the outside air. The environmental temperature measurement unit 33a measures the environmental temperature information via a built-in thermistor. If the thermistor itself is installed within the intravascular plasma index measurement device 2, the environmental temperature information detected via the thermistor can be considered to be the temperature inside the intravascular plasma index measurement device 2. The environmental temperature measurement unit 33a outputs this detected environmental temperature information to the body temperature calculation circuit 37 and the control circuit 18. The differential temperature measurement unit 33b measures differential temperature information. The differential temperature measurement unit 33b also includes a light-receiving element that receives infrared light emitted from the skin, which is the measurement site of the living body 6. The differential temperature measurement unit 33b measures differential temperature information based on the received infrared light. The differential temperature information is information relating to the difference between the environmental temperature information measured by the environmental temperature measurement unit 33a and the temperature of the measurement site (such as the skin of the living body) of the living body 6. The differential temperature measurement unit 33b outputs the measured differential temperature information to the body temperature calculation circuit 37.

[0084] In addition, the differential temperature measurement unit 33b can be directed toward the floor or ground on which the living body 6 is placed to receive infrared light emitted from the floor or ground, thereby understanding the temperature conditions around the living body 6 and obtaining the intravascular plasma index M, thereby making it possible to determine the level of safety of the living body 6.

[0085] The body temperature calculation circuit 37 receives environmental temperature information detected by the environmental temperature measurement unit 33a and differential temperature information measured by the differential temperature measurement unit 33b. The body temperature calculation circuit 37 calculates the sum of the environmental temperature information and the differential temperature information, and uses this as the temperature of the measurement site of the living body 6, which is the measurement target. The body temperature calculation circuit 37 converts the temperature information including the calculated body temperature information into an armpit body temperature and outputs it to the control circuit 18. The calculation processes of the temperature measurement unit 33 and the body temperature calculation circuit 37 may also be performed by the control circuit 18.

[0086] The light emission control circuit 36 ​​outputs a signal for causing the infrared light emitting unit 31 to emit the first light and a signal for causing the red light emitting unit 32 to emit the second light under the control of the control circuit 18 .

[0087] The contact sensor 26 is configured as a sensor for sensing whether or not the measurement portion of the living body 6 has made contact. When the contact sensor 26 senses contact of the measurement portion of the living body 6, it notifies the control circuit 18 of this fact, and if the contact sensor 26 does not detect a living body even if the power switch 15 is activated, it stops the light emission of the light emission control circuit 36. Furthermore, when the contact sensor 26 detects a living body, the contact sensor 26 is configured to automatically activate the power switch 15.

[0088] The living body 6 is, for example, a human being, but is not limited to this and may be any animal.

[0089] Next, an example of the operation of the intravascular plasma index measurement system 100 in this embodiment will be described. Figure 5 is a flowchart showing an example of the operation of the intravascular plasma index measurement system 100 in this embodiment. Figure 5(a) is a flowchart showing the operation of measuring the intravascular plasma index M using the first light.

[0090] First, in step 301, under the control of the control circuit 18, the infrared light emitter 31 irradiates the first light toward the skin of the living body 6. The wavelength of the first light may be either 1450 nm or 1950 nm, at which point water absorption is at its peak, but 970 nm is preferable because a wavelength of 1000 nm or less can reduce the size of the light receiving element. In step 301, the infrared light emitter 31 emits the first light at a T that is at least longer than the cardiac cycle of the living body 6. １ The first light is emitted toward the skin of the living body 6 for at least 1 second. The infrared light emitter 31 may also emit the first light toward any part of the living body 6 where blood vessels are present, such as an arm, an ear, or a fingertip.

[0091] Next, in step 302, the infrared light receiving unit 10 receives the first light transmitted through or reflected by the living body 6. When this received first light is transmitted through or reflected by the living body 6, it is affected by the blood pulsation. Therefore, when there is a lot of blood and blood plasma flowing, there is a lot of light absorption and a small amount of light due to the influence of water, which is the main component of blood plasma. When there is little blood flow, there is less light absorption and a large amount of light. Also, in step 302, the infrared light receiving unit 10 receives a T that is at least longer than the cardiac cycle of the living body 6. １ In step 302, the infrared light receiving unit 10 photoelectrically converts the received first light into an electrical signal and outputs the photoelectrically converted electrical signal of the first light to the intravascular plasma index calculation circuit 17.

[0092] Next, in step 303, the infrared light emitter 31 turns off the first light, and receives first extraneous light, which is extraneous light from indoors or outdoors that causes signal noise, with the infrared light receiver 10. The infrared light receiver 10 photoelectrically converts the received first extraneous light into an electrical signal and outputs this photoelectrically converted electrical signal of the first extraneous light to the intravascular plasma index calculation circuit 17. The first extraneous light is light different from the first light and does not include the first light irradiated from the infrared light emitter 31. The first extraneous light is, for example, extraneous light received by the infrared light receiver 10 when the infrared light emitter 31 is not irradiating the first light.

[0093] Next, in step 304, first photoelectric data is calculated and stored by subtracting the value obtained by photoelectrically converting the first extraneous light received in step 303 from the value obtained by photoelectrically converting the first light in step 302. These steps from step 301 to step 304 are preferably performed at a sampling rate of about 130 Hz, avoiding integer multiples of 50 Hz and 60 Hz for extraneous light such as fluorescent lamps.

[0094] Next, in step 305, the intravascular plasma index calculation circuit 17 determines whether or not the first photoelectric data of a plurality of pulses has been acquired. In step 305, the intravascular plasma index calculation circuit 17 determines whether or not the first photoelectric data of a plurality of pulses has been acquired. １The circuit 17 then determines whether or not the first photoelectric data for each second has been acquired. Since the human body has a pulsation rate of 50 to 100 beats per minute, for example, if 512 data points can be acquired at a sampling rate of 130 Hz, at least two beats of data can be acquired, and the circuit 17 determines that 512 data points is sufficient. If the acquired data points are insufficient, the process returns to step 301. If the acquired data points are sufficient, the process proceeds to step 306. If the living body 6 can be measured by the measuring device for a long period of time, it is preferable to acquire more data points for a longer period of time in order to obtain more accurate data.

[0095] Next, in step 306, the intravascular plasma index calculation circuit 17 calculates a DC value D based on the intensity of the first light from the first photoelectric data. １ The intravascular plasma index calculation circuit 17 calculates a DC value D, which is an average value (DC component) obtained by removing fluctuation components due to pulsation from the first photoelectric data. １ FIG. 6A shows the DC value D １ and AC value A １ FIG. 6C is a diagram showing the DC value D in the first photoelectric data when there is a water deficiency. １ and AC value A １ 1 is a diagram showing a DC value D １ is a value excluding the AC component, which is the change in plasma volume due to pulsation, as shown in FIG. 6(a). １ may be a constant based on the intensity of the first light calculated from the first photoelectric data. １ may be a value indicating an average intensity of the first light calculated from the first photoelectric data. １ may be, for example, an average value or an effective value of the amplitude of the first light. １ can be obtained by, for example, extracting multiple pulsation values ​​from the acquired first photoelectric data and averaging the values. １ is reduced by absorption of light by water contained in blood vessels and blood plasma of living tissues, and solid components such as melanin. １ decreases due to moisture in the skin caused by sweating. １and T ２ The calculation must be performed over a time that is an integral multiple of the heartbeat period of the living body.

[0096] In step 307, the intravascular plasma index calculation circuit 17 calculates an AC value A representing the amplitude of the first light from the first photoelectric data. １ The intravascular plasma index calculation circuit 17 calculates the fluctuation due to pulsation as an AC component, i.e., an AC value A １ Calculate and store AC value A １ is a value indicating the amplitude of the pulse of the living body 6. １ may be a value indicating the amplitude of the intensity of the first light calculated from the first photoelectric data. １ may be the average value of the amplitudes of multiple pulses. １ is calculated as, for example, the root mean square (RMS) value of the first photoelectric data. １ is the DC value D calculated from the first photoelectric data in step 306 １ The square root of the average value of the squared value within one beat may be calculated. １ is as shown in FIG. 6(a). Also, the AC value A １ The AC value A may be calculated by calculating the difference between the maximum value and the minimum value in one pulsation and averaging the difference between the maximum value and the minimum value for a plurality of measured pulsations. １ may be an amplitude obtained by Fourier transform. １ is affected by fluctuations in plasma volume due to pulsation. １ When the plasma volume decreases, the fluctuation range of the plasma in the pulsation decreases. １ decreases due to absorption of light by blood vessels, plasma in living tissue, melanin, and other solid components. １ is reduced by moisture in the skin due to sweating.

[0097] Next, in step 308, the intravascular plasma index calculation circuit 17 calculates A １ / D １ The intravascular plasma index calculation circuit 17 calculates, for example, A １ / D １is calculated as the measured value C. AC value A １ and DC value D １ The AC value A shown in Fig. 6(a) and Fig. 6(c) is attenuated and reduced at a common rate due to factors other than the reduction in light due to pulsation, i.e., the influence of sweating of nails, bones, and epidermis, which do not pulsate, and the influence of melanin in body tissues and skin. This is shown in Fig. 6(a) and Fig. 6(c). １ and DC value D １ Suppose that the amount of melanin in the skin of the living body 6, which has been measured, increases due to the influence of sunburn, etc. Then, the amount of light received by the infrared light receiving unit 10 decreases due to the influence of melanin, and the AC value A １ decreases, but the DC value D １ Therefore, the AC value A １ DC value D １ By dividing by , the common decreasing factors are canceled out and it becomes a dimensionless number. Also, when the plasma in the blood vessel decreases, the AC value A １ Since only A decreases, １ / D １ Therefore, the measured value C is not affected by the influence of sweating that is unrelated to dehydration, or by melanin in the body tissue or skin, and the influence of noise is removed, resulting in a value that correlates with the blood plasma in the blood vessels. １ / D １ If the value is small, the pulsation of the living body is weak and the AC value A １ The plasma volume is small, and the AC value A １ Here, since it is extremely rare for a living body to be dehydrated from the initial stage of using the casing 400, it is difficult to judge whether the average value C ＡＶ Obtain the measured value C and the average value C ＡＶ The intravascular plasma index M is calculated by comparing the blood pressure with the blood pressure. This will be explained next.

[0098] In step 309, the intravascular plasma index calculation circuit 17 calculates the average value C ＡＶ As A １ / D １ The average value of C is updated by dividing it proportionally based on the past usage time. ＡＶ Is T １ T longer than seconds２ This is a value relating to the average amplitude of the first light per second. ＡＶ For example, T ２ A for seconds １ / D １ The average value C ＡＶ is, for example, A for a period longer than 15 minutes. １ / D １ In step 309, the intravascular plasma index calculation circuit 17 calculates the average of the values ​​of A １ / D １ Based on this, the calculated and accumulated A １ / D １ The average value C ＡＶ Specifically, when the intravascular plasma index measurement device 2 can be attached to the living body 6 for 24 hours like the housing 400, A is updated, for example, once per minute. １ / D １ Measure and continuously １ / D １ Average value C ＡＶ The value of C is measured and constantly updated. ＡＶ It may be possible to reset the average value C to the initial value. ＡＶ When is reset, the average value C ＡＶ The time until the value of T stabilizes (for example, 3 hours) ２ Set it as seconds, T ２ Average value per second C ＡＶ may be used as a predetermined constant.

[0099] Next, in step 310, the intravascular plasma index calculation circuit 17 calculates the measured value C calculated in step 308 and the average value C calculated in step 309. ＡＶ In step 310, the intravascular plasma index calculation circuit 17 calculates the intravascular plasma index M based on the measured value C calculated in step 308 and the average value C calculated in step 309. ＡＶThe intravascular plasma index M is calculated based on the difference or ratio between

[0100] The value of the measured value C varies depending on the individual living body 6, and there are individual differences, especially depending on the amount of capillaries. On the other hand, the living body 6 takes in water by itself unless it is in a particularly excited state, so the amount of intravascular plasma is maintained at an appropriate level most of the time. Therefore, excluding abnormalities in the saturated oxygen concentration of hemoglobin due to pneumonia, etc., the measured value C takes an almost uniform value. Therefore, the measured value C and the average value C ＡＶ By observing the difference between these, it becomes possible to detect a decrease in intravascular plasma of the living body 6.

[0101] In step 310, the intravascular plasma index calculation circuit 17 calculates C−C ＡＶ The value of is raised to the nth power, multiplied by a constant K, and added with a constant L to obtain the intravascular plasma index M. For example, the constant K is 10,000 and the constant L is 100, but they are not limited to these and may be any constant.

[0102] M = K (C - C ＡＶ ) ｎ +L (1) where K, C ＡＶ , L, and n are constants.

[0103] In step 310, the intravascular plasma index calculation circuit 17 calculates C−C ＡＶ The value of is raised to the nth power, multiplied by a constant K, and added with a constant L to obtain the intravascular plasma index M.

[0104] M = K (C - C ＡＶ ) ｎ +L (3) where K, L, and n are constants, and C ＡＶ A １ / D １ The average value of C = A １ / D １ Let's say.

[0105] Here, the constant n in the exponentiation is, for example, 3, and by cubing it, (C - C ＡＶ ) there is a slight change in (C-C ＡＶ ) is small, it is numerically smaller, and (C - C ＡＶ ) has undergone a major change (C-CＡＶ ) is large, it is possible to express the intravascular plasma index M so that it becomes a larger value. Note that it is not limited to the third power, and it is preferable to use an odd power such as the fifth power or the seventh power. Also, since n is an odd power, (C - C ＡＶ Even if the value of (n) is negative, it can be used without changing the negative sign. Furthermore, the constant n does not have to be an integer.

[0106] In addition, since the calculated value is generally difficult to recognize if it is a decimal point, by multiplying it by a constant K, it is possible to make the intravascular plasma index M a numerical value that is easy for people to recognize, for example, a value of -10 to 10. ＡＶ ) ｎ The value obtained by multiplying by the constant K is close to "0" in a normal living body 6, and becomes negative when there is a shortage of plasma. Therefore, by adding a constant L of, for example, 100 to equation (1), a value of 100% or more than 100% is displayed when the intravascular plasma index M is sufficient, and when the intravascular plasma index M is small, a more appealing value such as 90% can be displayed. In addition, in order to reduce the load on the control circuit 18, the variables C and C ＡＶ The intravascular plasma index M may be calculated from a two-dimensional table corresponding to the above.

[0107] On the other hand, (CC ＡＶ ) is near 0, that is, the measured value C and the average value C ＡＶ When C-C are almost equal, there is no problem with dehydration. Also, when the variation between living bodies 6 and the range of fluctuation over time are taken into consideration, there is no need to issue a dehydration alert. Also, when the required amount of water is taken at once, ＡＶ may be on the positive side, but even in situations where the plasma volume is measured to be higher than normal, excluding special accidents, the living body 6 has intentionally taken in water, and so the risk of dehydration is also low.

[0108] However, (C-C ＡＶ ) is a significantly negative value, it indicates dehydration, so the value of the intravascular plasma index M is very important.ＡＶ ) on the vertical axis versus the intravascular plasma index M. Therefore, as shown in FIG. ＡＶ In a first region 550 from the negative side to the positive side of the constant g where g is near 0, the change in the intravascular plasma index M may be small, and in a second region 551 where g deviates significantly from the negative side to the negative side, the change in the intravascular plasma index M may be large. Alternatively, the intravascular plasma index M may be calculated using equation (2).

[0109] M = f(C - C ＡＶ ) (2) Here, f(x) is a function whose gradient is smaller than the differential value obtained by differentiating f(x) with respect to x when x is equal to or greater than a constant g, i.e., when x is smaller than the constant g. Furthermore, the function f(x) may be, for example, a linear function or a quadratic or higher order function whose gradient decreases when x exceeds g. Furthermore, for example, g may be a constant near 0 or -1<g<1.

[0110] This makes it possible to more accurately notify the user of the dehydration state and of the dangerous situation. Note that since it is clear that an abnormal situation exists when the third region 552 is too negative, it is also possible to display the intravascular plasma index M so that it does not fall below a reference value such as 60.

[0111] This completes the operation of measuring the intravascular plasma index M using the first light. Using a pulse wave of one or more beats in this manner eliminates the possibility of high harmonics due to vibrations such as arrhythmia or walking being observed, resulting in noise measurement, which is a concern when differentiating and analyzing one cycle of pulsation. This makes it possible to calculate the correct intravascular plasma ratio, thereby enabling a more accurate intravascular plasma index M to be obtained. Furthermore, detecting AC and DC components makes it possible to eliminate the influence of the average water content, individual differences in the body surface condition, melanin, fat present other than blood, and the light path, thereby enabling a more accurate intravascular plasma index M to be obtained. Furthermore, using light enables measurement to be performed non-invasively and easily on the living body 6. Non-contact measurement is also possible.

[0112] Next, an example of the operation of calculating the intravascular plasma index M using the first light and the second light in the intravascular plasma index measurement system 100 of this embodiment will be described. Fig. 5(b) is a flowchart showing the operation of measuring the intravascular plasma index M using the first light and the second light. Furthermore, since steps 401 to 404 are the same as steps 301 to 304 described above, a description thereof will be omitted.

[0113] In step 405, under the control of the control circuit 18, the red light emitter 32 irradiates the second light toward the skin of the living body 6. In addition, the red light emitter 32 irradiates substantially the same area as the area irradiated with the first light by the infrared light emitter 31 in step 301.

[0114] It is also preferable that the wavelength of the second light is shorter than that of the first light, and that the difference in the absorption coefficient of light by water is small. ２ 5A and 5B are diagrams showing the absorption coefficients of light in water, such as water. When infrared light of 970 nm, indicated by the first dashed line 501, is irradiated as the first light, it is preferable to use a wavelength of 800 nm or less, indicated by the second dashed line 502, so that the wavelength of the second light has a sufficiently low absorption coefficient of water. In this case, the difference in the absorption coefficient of light is the difference between the first point 511, which is the absorption coefficient on the first dashed line 501 at 970 nm, and the point 512, which is the absorption coefficient on the second dashed line 502 at a wavelength of 800 nm, which is approximately 10 times the difference. Furthermore, if the wavelength of the light emitted from the red light emitter 32 is near 660 nm, indicated by the third dashed line 503, the absorption coefficient of the light is lowered, thereby increasing the difference in the absorption coefficient with the first light emitted from the infrared light emitter 31, and improving the accuracy of the calculated value against noise. In this case, the difference in light absorption is the difference between the first point 511, which is the absorption coefficient at a wavelength of 970 nm, and the third point 513, which is the absorption coefficient at a wavelength of 660 nm, resulting in a large difference of about 100 times. On the other hand, since the light absorption coefficient of reduced hemoglobin shown in the Hb curve is large at wavelengths of 700 nm or less, in order to eliminate this effect, the influence of absorption by reduced hemoglobin may also be taken into consideration, and the value of intravascular plasma volume may be corrected using this measurement value. This configuration is possible by incorporating SpO ２This is effective when the device also has a built-in measurement function for measuring hemoglobin absorption. Furthermore, to perform accurate measurements without being significantly affected by hemoglobin absorption, a wavelength of approximately 730 nm, as indicated by the fourth dashed line 504, is preferable. In this case, the difference between the first point 511, which is the absorption coefficient at 970 nm, and the fourth point 514, which is the absorption coefficient at 730 nm, is approximately 20 times. Furthermore, as shown in the melanin absorption curve indicated by the dashed line in FIG. 8, the shorter the wavelength of the light source, the greater the light absorption by melanin. However, since melanin is primarily present in skin and is not affected by pulsation, it affects both the AC and DC components at any wavelength. Therefore, as described in step 308, the influence of the AC component can be offset by dividing the DC component by the AC component.

[0115] Next, in step 406, the red light receiving unit 11 receives the second light transmitted through or reflected by the living body 6. Here, since the second light is less absorbed by water than the first light, the received second light is less absorbed by water due to blood pulsation than the first light, and the reduction in light intensity is less than that of the first light. On the other hand, the influence of absorption of the second light by melanin, etc. is greater than that of the first light, and the light intensity of the second light is reduced compared to that of the first light.

[0116] Next, in step 407, the red light emitter 32 turns off the second light, and the red light receiver 11 receives second extraneous light, which is extraneous light from inside or outside the room that causes signal noise. The second extraneous light is light different from the second light and does not include the second light emitted from the red light emitter 32. The second extraneous light is extraneous light that is received by the red light receiver 11 when, for example, the red light emitter 32 is not emitting the second light.

[0117] Next, in step 408, second photoelectric data is calculated and stored by subtracting the value obtained by photoelectrically converting the second extraneous light received in step 407 from the value obtained by photoelectrically converting the second light in step 406. These steps from step 405 to step 408 are preferably performed at a sampling rate of about 130 Hz, avoiding integer multiples of 50 Hz and 60 Hz for extraneous light such as fluorescent lamps.

[0118] Next, in step 409, the intravascular plasma index calculation circuit 17 determines whether or not second photoelectric data of multiple pulsations have been acquired, similarly to step 305. If the acquired second photoelectric data is insufficient, the process returns to step 401;

[0119] Next, in step 410, similarly to step 306, the intravascular plasma index calculation circuit 17 calculates a DC value D based on the intensity of the first light from the first photoelectric data. １ Calculate the DC value D １ The values ​​are as shown in FIG.

[0120] Next, in step 411, similarly to step 307, the intravascular plasma index calculation circuit 17 calculates an AC value A １ Calculate AC value A １ may be the average value of the amplitude of a plurality of pulses. １ For example, the effective value (RMS) of the first photoelectric data may be used, and the value is as shown in FIG. 6(a).

[0121] Next, in step 412, similarly to step 306, the intravascular plasma index calculation circuit 17 calculates a DC value D based on the intensity of the second light from the second photoelectric data. ２ Calculate the DC value D ２ is the DC value D １ This value is less affected by absorption by water contained in plasma compared to the value above.

[0122] Next, in step 413, similarly to step 307, the intravascular plasma index calculation circuit 17 calculates an AC value A ２ Calculate AC value A ２ is the AC value A １ This value is less affected by absorption by water contained in plasma compared to the DC value D ２ and AC value A ２ FIG. 6(d) is a diagram showing the DC value D in the second photoelectric data when there is a water deficiency. ２ and AC value A ２ 1 is a diagram illustrating an AC value A of the first light. １ and DC value D１ This value shows no absorption due to moisture compared to AC value A. ２ and DC value D ２ Since the influence of water is small, even if the blood plasma in the blood vessels decreases, there is no significant effect, and as shown in Figure 6(d), there is no significant difference from Figure 6(b). Also, even if the melanin in the skin changes due to sunburn or the like and the waveform of Figure 6(d) changes, the AC value A １ and DC value D １ Similarly, the AC value A ２ and DC value D ２ Since both are affected by melanin, as will be described later, the AC value A ２ DC value D ２ By dividing by this, it is possible to offset the effects of changes in melanin, etc.

[0123] In step 405, when the red light emitting unit 32 emits a wavelength of 660 nm, which is easily affected by hemoglobin, the AC value A ２ and DC value D ２ may be affected by hemoglobin. In particular, this effect is ２ The DC value D ２ For example, when the saturated oxygen concentration is low, that is, when the proportion of oxygenated hemoglobin in the blood is judged to be low, the proportion of reduced hemoglobin, which has a high absorption coefficient at a wavelength of 660 nm, may be higher than that of oxygenated hemoglobin, which has a low absorption coefficient at a wavelength of 660 nm. ２ Therefore, in step 413, SpO ２ The measurement unit 23 measures the oxygen information and calculates the AC value A based on the measured oxygen information. ２ The value of SpO may be corrected. ２ The measurement unit 23 measures, for example, the blood saturated oxygen concentration (SpO ２ ) so that the AC value A ２ The value of may be corrected.

[0124] Next, in step 414, the intravascular plasma index calculation circuit 17 calculates (A１ / D １ ) / (A ２ / D ２ ) is calculated, and (A １ / D １ ) / (A ２ / D ２ ) is the measured value C. DC value D １ As shown in FIG. 6(c), there is a decrease due to the influence of factors other than pulsation, and the AC value A １ The AC value A １ DC value D １ By dividing by, the common decreasing factors are canceled out, resulting in a value that is highly correlated with intravascular plasma. ２ is the AC value A １ Compared to the DC value D, it is less susceptible to the absorption of water and is therefore less susceptible to the decrease in light intensity due to a decrease in plasma. １ Therefore, the change in blood plasma due to the increase or decrease in blood plasma (A ２ / D ２ ) changes as follows: (A １ / D １ ) is tiny compared to

[0125] Here, the AC value A measured with the first light, which has a large absorption coefficient of water, is most affected by the decrease in intravascular plasma. １ Therefore, the measured value C is calculated as a smaller value as the amount of plasma in the blood vessels decreases. Note that the AC value A varies depending on the individual differences in the amount of capillaries and the strength of the pulsation. １ The change in the DC value D １ However, in this case, the change in AC value A ２ and DC value D ２ The same is true for AC value A ２ The change in the DC value D ２ This means that the change in (A １ / D １ ) to (A ２ / D ２ ) makes it possible to measure a stable value without variation between individuals of the living organism 6.

[0126] Next, in step 415, the intravascular plasma index calculation circuit 17 calculates the average value C ＡＶ Here, as in step 309, the intravascular plasma index calculation circuit 17 sets the average value C ＡＶ The measured value C is expressed as (A １ / D １ ) / (A ２ / D ２ ) is updated based on the past usage time. In addition, when two different wavelengths of the first light and the second light are used, the average value C ＡＶ Therefore, when a plurality of living bodies 6 alternately use the intravascular plasma index measurement system 100, the intravascular plasma index calculation circuit 17 prioritizes convenience and sets C ＡＶ may be set as a constant. The intravascular plasma index calculation circuit 17 always calculates the average value C ＡＶ = 1.35 in advance, and step 415 may be omitted.

[0127] Furthermore, when comparing adult men and women, the proportion of plasma is sometimes greater in adult women. This is thought to be because women have less hemoglobin in their blood than men, and are closer to a state of anemia. The proportion of plasma also differs depending on the attributes of the living body 6, such as age. For this reason, for example, in step 415, attribute information relating to the attributes of the living body 6 is acquired, and the average value C ＡＶ The attribute information may be information such as the sex, age, race, nationality, and chronic illness of the living body 6. FIG. 9 shows the average value C ＡＶ In this case, the intravascular plasma index calculation circuit 17 operates in accordance with the flowchart shown in FIG.

[0128] First, in step 801, the intravascular plasma index calculation circuit 17 acquires attribute information including whether the living body 6 to be measured is male or female and information on the living body's age. The intravascular plasma index calculation circuit 17 may acquire this information by any method. The information on age may be information on the current age or date of birth.

[0129] Next, in step 802, the intravascular plasma index calculation circuit 17 determines whether the living body 6 is "male, aged 15 to under 70" based on the information acquired in step 801. If the living body 6 is "male, aged 15 to under 70", the intravascular plasma index calculation circuit 17 proceeds to step 803. Also, in step 802, if the living body 6 is not "male, aged 15 to under 70", the intravascular plasma index calculation circuit 17 proceeds to step 804. In step 804, the intravascular plasma index calculation circuit 17 determines whether the living body 6 is "female, aged 12 to under 60". If the living body 6 is "female, aged 12 to under 60", the intravascular plasma index calculation circuit 17 proceeds to step 805, and if not, the intravascular plasma index calculation circuit 17 proceeds to step 806.

[0130] In step 803, the intravascular plasma index calculation circuit 17 calculates the average value C ＡＶ In step 805, the intravascular plasma index calculation circuit 17 calculates the average value C ＡＶ In step 806, the intravascular plasma index calculation circuit 17 sets the average value C ＡＶ = 1.35. This average value C ＡＶ The setting of the average value C may be performed at any timing. For example, it may be set in advance before using the intravascular plasma index measurement system 100, or may be set in step 415. ＡＶ The value may be set in finer increments, for example, in increments of 0.01.

[0131] In addition, for example, when the housings 300 for men, women, children, and the elderly are prepared in advance and the housing 300 for men is used, the average value C ＡＶ = 1.35, and when the female housing 300 is used, the average value C ＡＶ = 1.4, and when using the housings 300 for children and elderly people, the average value C ＡＶ You can also set it to =1.35.

[0132] Next, in step 416, the intravascular plasma index calculation circuit 17 calculates the intravascular plasma index M in the same manner as in step 310. In step 416, the intravascular plasma index calculation circuit 17 calculates C-C ＡＶ The value of is raised to the nth power, multiplied by a constant K, and added with a constant L to obtain the intravascular plasma index M.

[0133] C = (A １ / D １ ) / (A ２ / D ２ ) (5) M=K(C-C ＡＶ ) ｎ +L (6) where K, C ＡＶ , L, and n are constants.

[0134] In step 416, the intravascular plasma index calculation circuit 17 calculates C−C ＡＶ The value of is raised to the nth power, multiplied by a constant K, and added with a constant L to obtain the intravascular plasma index M.

[0135] C = (A １ / D １ ) / (A ２ / D ２ ) (7) M=K(C-C ＡＶ ) ｎ +L (8) where K, L, and n are constants, and C ＡＶ is (A １ / D １ ) / (A ２ / D ２ ) is the average value.

[0136] In addition, in step 416, the intravascular plasma index calculation circuit 17 may calculate the intravascular plasma index M using, for example, equations (9) and (10).

[0137] C = (A １ / D １ ) / (A ２ / D ２ ) (9) M=f(CC ＡＶ) (10) where f(x) is a function whose gradient is smaller than the differential value obtained by differentiating f(x) with respect to x when x is equal to or greater than the constant g, compared to the differential value when x is smaller than the constant g. The function f(x) may be a linear function or a quadratic or higher order function whose gradient becomes smaller when x exceeds g.

[0138] This completes the operation of measuring the intravascular plasma index M using the first light and the second light. As a result, a noise-removed intravascular plasma index (A １ / D １ ) / (A ２ / D ２ ) can be used to calculate the intravascular plasma index M with high accuracy. Furthermore, compared to the case where the intravascular plasma index M is measured using only the first light, the influence of individual differences between living bodies 6 is reduced, so there is little influence even if multiple living bodies 6 use the same intravascular plasma index measuring device 2.

[0139] Next, an example of the operation after calculating the intravascular plasma index M in the intravascular plasma index measurement system 100 of this embodiment will be described. Figure 10 is a diagram showing a flowchart of the operation after calculating the intravascular plasma index M in the intravascular plasma index measurement system 100 of this embodiment. After calculating the intravascular plasma index M in step 310 or step 416, the intravascular plasma index calculation circuit 17 proceeds to step 601.

[0140] First, in step 601, the environmental temperature measurement unit 33a acquires the environmental temperature information Te.

[0141] Next, in step 602, the differential temperature measurement unit 33b measures the differential temperature between the measurement site of the living body 6 (such as the skin of the living body) and the environment, and adds the differential temperature to the environmental temperature information measured in step 601 to calculate temperature information including the body temperature T of the living body 6. The temperature information is information related to temperature, and includes, for example, the body temperature T of the living body, differential temperature information, environmental temperature information, etc.

[0142] Next, in step 603, SpO ２The measurement unit 23 acquires oxygen information. In this case, when measurement is performed using a known method of acquiring oxygen information using infrared rays, the wavelength of the infrared rays can be set to 1000 nm or less, thereby making it possible to miniaturize the light receiving element, and therefore the overall size of the intravascular plasma index measurement device 2 can be reduced.

[0143] Next, in step 604, the intravascular plasma index calculation circuit 17 acquires pulse information relating to the pulse rate P of the living body 6. The intravascular plasma index calculation circuit 17 may calculate the heart rate P per minute based on the photoelectric data acquired in the above-mentioned step 409, for example, and use the calculated heart rate P as pulse information.

[0144] Next, in step 605, the control circuit 18 determines whether there is an abnormality in the living body 6 based on the oxygen information. ２ If the value of is equal to or less than a predetermined value, that is, if the saturated oxygen concentration in the blood has decreased and it is determined that the living body 6 is in danger, the process proceeds to step 616 and an emergency response is taken. ２ If the value of is greater than the predetermined value, the process proceeds to step 606. Furthermore, the abnormality of the living body 6 is, for example, heat stroke or dehydration, but is not limited to these and may be a tendency of any symptom.

[0145] Next, in step 606, the control circuit 18 determines whether or not there is an abnormality in the living body 6 based on the intravascular plasma index M. In step 606, the control circuit 18 determines, for example, whether the intravascular plasma index M is smaller than a predetermined value. If the intravascular plasma index M is smaller than the predetermined value, the control circuit 18 determines that there is a lack of water in the blood vessels and proceeds to step 608. If the intravascular plasma index M is equal to or greater than the predetermined value, the control circuit 18 proceeds to step 607.

[0146] 11 is a diagram showing an example of the display unit 12. Next, in step 607, the display unit 12 displays, for example, as shown in FIG. 11(a), the intravascular plasma index (blood plasma) M, the ambient temperature (Temp.) Te, the body temperature (Body Temp.) T, the heart rate (Heart rate) P, the saturated oxygen concentration in the blood (SpO2) SpO ２The intravascular plasma index measurement system 100 may also proceed to step 301, step 401, or step 601 again.

[0147] Next, in step 608, the control circuit 18 determines whether there is an abnormality in the living body 6 based on the temperature information. In step 608, the control circuit 18 determines, for example, whether the environmental temperature Te is higher than a predetermined value. If the environmental temperature Te is higher than the predetermined value, the control circuit 18 determines that the living body 6 is in danger because the intravascular plasma index M of the living body is low, indicating the possibility of dehydration, and the environmental temperature is high, and proceeds to step 612. If the environmental temperature Te is below the predetermined value, the control circuit 18 determines that there is little risk of a rapid decrease in plasma moisture due to sweating or the like and therefore does not pose a significant danger, and proceeds to step 609. Note that as dehydration progresses, the heart rate increases by approximately 4 to 6 bpm for every 1% loss in body weight. Heart rate also increases due to exercise, but if there is a tendency for dehydration and the heart rate P obtained in step 604 is higher than normal, the control circuit 18 may proceed to step 602 and issue a loud warning because there is a high risk of dehydration.

[0148] Next, in step 609, the vibration unit 21 generates vibrations to warn the living body 6. This makes it possible to notify the living body 6 of the possibility of dehydration and the danger of neglecting to drink water, even when the living body 6 is concentrating on an event or the like.

[0149] Next, in step 610, the sound generator 22 generates a sound or voice to warn of danger, thereby making it possible to notify the living body 6 and nearby third parties of the danger.

[0150] Next, in step 611, the display unit 12 displays the intravascular plasma index M, the environmental temperature Te, the body temperature T, the heart rate P, and the SpO2, as shown in FIG. 11(b), for example. ２The display unit 12 may display the value and a message to prompt the user to drink water, as shown in FIG. 11(b), when the living body 6 needs to drink water. The display unit 12 may also display a plastic bottle along with the word "Water" as shown in FIG. 11(b). The intravascular plasma index measurement system 100 may also proceed to step 301, step 401, or step 601 again.

[0151] Furthermore, if a person drinks a large amount of fluid due to thirst, the proportion of plasma in the blood temporarily increases. This increase in the proportion of plasma in the blood is not usually a problem and is known to return to normal over time, but in some cases it may have a negative effect on the living body 6. For example, if the proportion of plasma in the blood increases, the amount of water, which is the main component of plasma, increases, which also increases intraocular pressure. This high intraocular pressure can cause, for example, glaucoma. In response to this, the display unit 12 may issue a warning to a person with a high intraocular pressure when the proportion of plasma is high, advising not to drink more fluid, and encouraging the person to drink fluids slowly after the warning disappears.

[0152] Next, in step 612, the control circuit 18 determines whether the body temperature T is higher than a predetermined value. If the body temperature T is higher than the predetermined value, the control circuit 18 determines that the living body 6 is in danger because the body temperature may not be regulated by sweating and the environmental temperature Te is also high, and proceeds to step 616. If the body temperature T is equal to or lower than the predetermined value, the control circuit 18 proceeds to step 613.

[0153] Next, in step 613, the intravascular plasma index of the living body is low and the environmental temperature is high, so the living body is in a state where it is at greater risk of dehydration than in the state of step 609. Therefore, the vibration unit 21 generates vibrations to warn the living body 6. This makes it possible to notify the living body 6 of the danger even when the living body 6 is concentrating on an event or the like.

[0154] Next, in step 614, the sound output unit 22 generates a sound or voice to notify the living body 6 of the danger. In step 614, the sound output unit 22 may generate a sound or voice that is louder than that generated in step 610. This makes it possible to notify the living body 6 and nearby third parties of the danger.

[0155] Next, in step 615, the display unit 12 displays the intravascular plasma index M, the environmental temperature Te, the body temperature T, and the SpO2 as shown in FIG. 11(c). ２ In addition to displaying the value, because the condition is more urgent, a message is displayed urging the patient to obtain oral rehydration water supplemented with various minerals rather than just water, thereby encouraging the patient to obtain the necessary water and minerals. Furthermore, when the living body 6 needs oral rehydration solution, the display unit 12 may display the name of the oral rehydration solution (ORS) along with a plastic bottle of oral rehydration solution, as shown in FIG. 11( c). Alternatively, the intravascular plasma index measurement system 100 may proceed again to step 301, step 401, or step 601.

[0156] Next, in step 616, since the intravascular plasma index M is low, and the environmental temperature Te and body temperature T are high, which indicates an extremely dangerous situation for the living body 6, the vibration unit 21 generates strong vibrations to warn the living body 6. This makes it possible to notify the living body 6 of a great danger even in a situation where the living body 6's thinking has partially stopped.

[0157] Next, in step 617, the sound output unit 22 generates a sound or voice to notify of danger. In step 617, the sound output unit 22 may generate a louder sound or voice than in step 614. This makes it possible to notify the living body 6 and nearby third parties that there is a great danger.

[0158] Next, in step 618, the display unit 12 displays the SpO ２ , the intravascular plasma index M, the environmental temperature Te, the body temperature T, and the heart rate P, and also indicates that the condition is critical. Furthermore, if it is determined that the life of the living body 6 is in danger, the display unit 12 may display "CRITICALLY ILL" as shown in FIG. 11(d).

[0159] Next, in step 619, the communication unit 13 notifies a medical institution and prompts them to take measures to ensure the safety of the living body 6. In addition, the intravascular plasma index measurement system 100 may proceed to step 301, step 401, or step 601 again.

[0160] Although the embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as defined in the claims.

[0161] 1: Sensor 2: Vascular plasma index measuring device 3: Server 4: Public communication network 6: Living body 7: User terminal 10: Infrared light receiving unit 11: Red light receiving unit 12: Display unit 13: Communication unit 14: Connector 15: Power switch 17: Vascular plasma index calculation circuit 18: Control circuit 19: Battery 21: Vibration unit 22: Sounding unit 23: SpO ２ Measurement unit 26: Contact sensor 31: Infrared light emitter 32: Red light emitter 33: Temperature measurement unit 33a: Environmental temperature measurement unit 33b: Differential temperature measurement unit 36: Light emission control circuit 37: Body temperature calculation circuit 41: First housing 100: Intravascular plasma index measurement system 300: Housing 301: Upper housing 302: Upper recess 304: Shaft 341: Lower housing 342: Lower recess 400: Housing 401a: Surface 401b: Back surface 402: Wristband 501: First dashed line 502: Second dashed line 503: Third dashed line 504: Fourth dashed line 511: First point 512: Second point 513: Third point 514: Fourth point 550: First area 551: Second area 552: Third area

Claims

1. A first irradiating means for irradiating a living body with a first light; a first light receiving means for receiving the first light irradiated by the first irradiating means and transmitted or reflected by the living body; and a T longer than a heartbeat period of the living body based on the first light received by the first light receiving means. １ a first calculation means for calculating a measurement value C relating to the amplitude of the first light for a period of time T seconds based on the first light received by the first light receiving means; １ T longer than 2 seconds ２ The average value C of the amplitude of the first light for seconds ＡＶ a second calculation means for calculating the measured value C calculated by the first calculation means and an average value C calculated by the second calculation means; ＡＶ and a third calculation means for calculating an intravascular plasma index M relating to the plasma in the blood vessel of the living body based on the above.

2. The intravascular plasma index measurement system according to claim 1, wherein the third calculation means calculates the intravascular plasma index M using the following formula (1). M = K(C - C ＡＶ ) ｎ + L (1) Here, K, L, and n are constants.

3. The intravascular plasma index measurement system according to claim 1, wherein the third calculation means calculates the intravascular plasma index M using the following formula (2). M = f(C - C ＡＶ ) (2) Here, f(x) is a function such that the derivative of f(x) with respect to x when x is greater than or equal to a constant g is smaller than the derivative when x is smaller than the constant g.

4. The first calculation means calculates the measurement value C based on the alternating current value A indicating the amplitude of the first light and the direct current value D based on the intensity of the first light, which are received by the first light receiving means. １ and the direct current value D based on the intensity of the first light １ and extracts the extracted alternating current value A １ and the direct current value D １ The intravascular plasma index measurement system according to claim 1, characterized in that the measurement value C is calculated based on the above.

5. The intravascular plasma index measurement system according to claim 4, wherein the third calculation means calculates the intravascular plasma index M using the following formula (3). M = K(C - C ＡＶ ) ｎ + L (3) Here, K, L, and n are constants, and C = A １ / D １ is set as such.

6. The intravascular plasma index measurement system according to claim 4, wherein the third calculation means calculates the intravascular plasma index M using the following formula (4). M = f(C - C ＡＶ ) (4) Here, f(x) is a function such that the derivative of f(x) with respect to x when x is greater than or equal to a constant g is smaller than the derivative when x is smaller than the constant g, and C = A １ / D １ .

7. A first irradiation means for irradiating a living body with a first light, a first light receiving means for receiving the first light that has been irradiated by the first irradiation means and transmitted or reflected by the living body, and an alternating current value A indicating the amplitude of the first light based on the first light received by the first light receiving means １ and a direct current value D based on the intensity of the first light １ and a first calculation means for extracting them; a second irradiation means for irradiating the living body with a second light having a wavelength shorter than that of the first light and a water absorption characteristic smaller than that of the first light, a second light receiving means for receiving the second light that has been irradiated by the second irradiation means and transmitted or reflected by the living body, and an alternating current value A indicating the amplitude of the second light based on the second light received by the second light receiving means ２ and a direct current value D based on the intensity of the second light ２ and a second calculation means for extracting them; an alternating current value A calculated by the first calculation means and the second calculation means １ and an alternating current value A ２ and a direct current value D １ and a direct current value D ２ and a third calculation means for calculating an intravascular plasma index M regarding plasma in blood vessels of the living body based on them. An intravascular plasma index measurement system characterized by comprising the above 8. The intravascular plasma index measurement system according to claim 7, wherein the third calculation means calculates the intravascular plasma index M using the following equations (5) and (6). C = (A １ / D １ ) / (A ２ / D ２ ) (5) M = K(C - C ＡＶ ) ｎ + L (6) Here, K, C ＡＶ , L, and n are constants.

9. The said 3rd calculation means calculates the intravascular plasma index M by using the following formulas (7) and (8), and is characterized by the intravascular plasma index measurement system according to Claim 7. C = (A １ / D １ )(A ２ / D ２ )(7) M = K(C - C ＡＶ )(8) Here, K, L, and n are constants, and C ｎ is the average value of (A ＡＶ / D １ )(A １ / D ２ / D ２ ).

10. The intravascular plasma index measuring system according to claim 7, wherein the third calculating means calculates the intravascular plasma index M using the following formulas (9) and (10). C = (A １ / D １ ) / (A ２ / D ２ ) (9) M = f(C - C ＡＶ ) (10) Here, f(x) is a function such that the derivative of f(x) with respect to x when x is greater than or equal to a constant g is smaller than the derivative when x is smaller than the constant g, and C ＡＶ is the average value or a constant of (A １ / D １ ) / (A ２ / D ２ ).

11. The intravascular plasma index measurement system according to claim 1, wherein the wavelength of the first light has a wavelength included in any one of 960 nm to 980 nm, 1440 nm to 1460 nm, and 1930 nm to 1950 nm.

12. The intravascular plasma index measurement system according to claim 7, wherein the wavelength of the first light has a wavelength included in any one of 960 nm to 980 nm, 1440 nm to 1460 nm, and 1930 nm to 1950 nm, and the second light has a wavelength of 800 nm or less.

13. The intravascular plasma index measurement system according to claim 1, further comprising any one or more of a display means for displaying the intravascular plasma index M calculated by the third calculation means, a vibration means for generating vibration based on the intravascular plasma index M calculated by the third calculation means, a communication means for communicating the intravascular plasma index M calculated by the third calculation means to an external device, and a sound means for generating sound based on the intravascular plasma index M calculated by the third calculation means.

14. The intravascular plasma index measurement system according to claim 1, further comprising an acquisition means for acquiring temperature information regarding temperature, and a determination means for determining an abnormality of the living body based on the temperature information acquired by the acquisition means and the intravascular plasma index M calculated by the third calculation means.

15. The intravascular plasma index measurement system according to claim 1, further comprising an acquisition means for acquiring oxygen information regarding the blood saturation oxygen concentration of the living body, and a determination means for determining an abnormality of the living body based on the oxygen information acquired by the acquisition means and the intravascular plasma index M calculated by the third calculation means.

16. The intravascular plasma index measurement system according to claim 1, wherein the first light receiving means receives a first external light different from the first light, and the first calculation means corrects the measurement value C based on the first external light received by the first light receiving means.

17. The first light receiving means receives first external light different from the first light, and the first calculating means corrects any one or more of the alternating current value A １ and the direct current value D １ based on the first external light received by the first light receiving means. The second light receiving means receives second external light different from the second light, and the second calculating means corrects any one or more of the alternating current value A ２ and the direct current value D ２ based on the second external light received by the second light receiving means. The intravascular plasma index measurement system according to claim 7, characterized in that.

18. The intravascular plasma index measurement system according to claim 1, further comprising an acquisition means for acquiring pulse information regarding the pulse rate of the living body, and a determination means for determining an abnormality of the living body based on the pulse information acquired by the acquisition means and the intravascular plasma index M calculated by the third calculation means.

19. Acquisition means for acquiring any one or more of temperature information regarding temperature, oxygen information regarding the blood oxygen saturation concentration of the living body, and pulse information regarding the pulse rate of the living body; and based on any one or more of the temperature information, oxygen information, and pulse information acquired by the acquisition means and the intravascular plasma index M calculated by the third calculation means, determination means for determining the type of moisture to be prescribed to the living body. The intravascular plasma index measurement system according to claim 1, further comprising the above.

20. The third calculation means acquires attribute information regarding the attributes of the living body, and based on the acquired attribute information, sets the C ＡＶ The intravascular plasma index measurement system according to claim 8, characterized by the above.

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