Patent Application
20160228055
This application claims the benefit of Japanese Patent Application No. 2015-020899, filed on Feb. 5, 2015. The content of the aforementioned application is incorporated herein by reference in its entirety.
1. Technical Field
The present invention relates to a vaporization heat quantity measuring device and the like which measures the quantity of heat of vaporization.
2. Related Art
The body temperature of a human body is maintained by the heat dissipated from the human body. The metabolism to maintain the body temperature is called basal metabolism. That is, the metabolic rate can be learned by measuring dissipation from the human body. Heat dissipation is generated by the perspiration function, which is a physiological function of the human body. Specifically, the human body perspires through sweat glands in the skin and vaporizes (evaporates) water from the skin surface, thus dissipating heat outside the body as heat of vaporization (evaporative heat loss).
JP-A-2011-120917 discloses a technique of finding physiological information or context information from the wearer's body. For example, the publication discloses a method of acquiring heart rate, pulse rate, respiratory rate, heat flow, oxygen consumption and the like and thus finding the calories burned and basal metabolic rate.
While JP-A-2011-120917 discloses a configuration for detecting the amount of perspiration by measuring the electrical skin resistance, it does not disclose a technique of finding the evaporative heat loss, that is, the quantity of heat of vaporization due to perspiration. Since how much of the perspiration water is evaporated varies depending on the humidity and water vapor pressure in the external environment, there are cases where the quantity of heat of vaporization cannot be accurately measured on the basis of the amount of perspiration alone, for example, at the time of exercise or in hot environment or the like where the person perspires a lot.
This problem is not limited to the case where the measuring target is a human body. The same applies to measuring the quantity of heat of vaporization due to perspiration of other organisms and also to measuring the quantity of heat of vaporization in objects which generate heat of vaporization.
An advantage of some aspects of the invention is that the quantity of heat of vaporization from a measurement target can be measured.
A first aspect of the invention is directed to a vaporization heat quantity measuring device including: a contact thermometer which contacts a surface of a measuring target and measures a temperature of the surface (first temperature); a radiation thermometer which measures a second temperature of the surface of the measuring object; and a computing unit which calculates a quantity of heat of vaporization, using the first temperature and the second temperature.
As water evaporates from the surface of the measuring object, heat of vaporization is taken away and therefore the temperature of the surface drops. However, since the portion which the contact thermometer contacts is not exposed to the external environment, a temperature drop is less likely to happen. Therefore, the second temperature measured of the surface of the measuring target is lower than the first temperature measured in contact with the surface. According to the first aspect of the invention, the quantity of heat of vaporization from the measuring target can be measured, using the first temperature and the second temperature of the surface of the measuring target.
A second aspect of the invention is directed to the vaporization heat quantity measuring device according to the first aspect of the invention, in which the computing unit executes predetermined vaporization heat quantity computing processing in which the first temperature and the second temperature are variables, and thus may calculate the quantity of heat of vaporization.
According to the second aspect of the invention, the quantity of heat of vaporization can be calculated by the computing processing using the first temperature and the second temperature.
A third aspect of the invention is directed to the vaporization heat quantity measuring device according to the second aspect of the invention, in which the computing unit executes computing processing in which the quantity of heat of vaporization is calculated on the basis of a linear sum of the first temperature and the second temperature, as the vaporization heat quantity computing processing.
According to the third aspect of the invention, the quantity of heat of vaporization can be calculated on the basis of the linear sum of the first temperature and the second temperature.
A fourth aspect of the invention is directed to the vaporization heat quantity measuring device according to the second aspect of the invention, in which the computing unit executes computing processing in which the quantity of heat of vaporization is calculated on the basis of a sum of squares of the first temperature and the second temperature, as the vaporization heat quantity computing processing.
According to the fourth aspect of the invention, the quantity of heat of vaporization can be calculated on the basis of the sum of squares of the first temperature and the second temperature.
A fifth aspect of the invention is directed to a biological information measuring device including a plurality of the vaporization heat quantity measuring devices according to any of the first to fourth aspects of the invention which measure the quantity of heat of vaporization at different sites on a living body as the measuring target, in which the biological information measuring device measures biological information including at least a metabolic rate of the living body, using the quantity of heat of vaporization measured at each of the sites.
According to the fifth aspect of the invention, the quantity of heat of vaporization can be measured at a plurality of sites of the living body and the metabolic rate of the living body can be measured on the basis of the quantity of heat of vaporization at each site.
A sixth aspect of the invention is directed to a biological information measuring device including: the vaporization heat quantity measuring device according to any of the first to fourth aspects of the invention which measures the quantity of heat of vaporization from a living body as the measuring target; and a heat flow meter which measures a heat flow generated on a surface of the living body, in which the biological information measuring device measures biological information including at least a metabolic rate of the living body, using the quantity of heat of vaporization measured by the vaporization heat quantity measuring device and the heat flow measured by the heat flow meter.
According to the sixth aspect of the invention, the metabolic rate of the living body can be measured on the basis of the quantity of heat of vaporization from the living body and the heat flow generated on the surface of the living body.
A seventh aspect of the invention is directed to an electronic apparatus mounted on a skin surface at a predetermined site of a user by having a band thereof wound on the site, including: a contact thermometer which contacts the skin surface and measures a first temperature of the skin surface; a radiation thermometer which measures a second temperature of the skin surface; and a computing unit which calculates a quantity of heat of vaporization, using the first temperature and the second temperature.
According to the seventh aspect of the invention, an electronic apparatus having advantageous effects similar to those of the first aspect can be achieved.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
Hereinafter, a form of embodiment for carrying out the vaporization heat quantity measuring device and the like according to the invention will be described. However, the invention is not limited to the embodiment described below and the form of embodiment to which the invention is applicable is not limited to the embodiment below, either. In the drawings, the same parts are denoted by the same reference numbers.
First, as a first embodiment, an electronic apparatus which is mounted on a user and measures the quantity of heat of vaporization due to perspiration (hereinafter also referred to as “quantity of heat of perspiration vaporization”) If the quantity of heat of perspiration vaporization is known, heat dissipation to the outside from the body due to perspiration can be grasped. Heat dissipation from a human body is related to human homeostasis such as thermoregulation, for example. Therefore, knowing this is important for health sciences and medicine.
The electronic apparatus 1 has an operation switch 11 on a lateral side of the main body case 10, as an operation input unit, and has a touch panel 12 which also functions as an image display unit, on a face side of the main body case 10 (the side facing outward when the apparatus is mounted on the user 100). The user 100 can input various operations such as measurement start operation, using these components.
On a lateral side of the main body case 10, a communication device 13 where a wire cable for communicating with an external device can be attached and removed, and a reader/writer 14 which implements reading data from and writing data into a memory card 15. The main body case 10 also contains a rechargeable built-in battery 16, a control board 17, a thermometer unit 30, and a heat flow meter 60.
The communication device 13 can be materialized by a wireless communication module and an antenna, if it is to have a configuration for performing wireless communication with an external device. The memory card 15 is a removable non-volatile memory in which data is rewritable. As the memory card 15, a rewritable non-volatile memory such as a FeRAM (ferroelectric random access memory) or MRAM (magnetoresistive random access memory) as well as flash memory can be used.
The charging method for the built-in battery 16 can be set suitably according to need. For example, an electrical contact may be separately provided on the back side of the main body case 10, and the main body case 10 may be set in a cradle connected to a household power supply so that the built-in battery 16 can be electrified and charged via the electrical contact and the cradle. Alternatively, contactless wireless charging may be used.
The control board 17 is equipped with a CPU (central processing unit) 171 and a storage medium 173 such as an IC (integrated circuit) memory or hard disk. Also, necessary electronic components such as an ASIC (application specific integrated circuit) and various other integrated circuits can be suitably installed according to need. The electronic apparatus 1 implements various functions such as vaporization heat quantity measurement, by causing the CPU 171 to execute a program stored in the storage medium 173.
The thermometer unit 30 is made up of a contact thermometer 40 and a radiation thermometer 50. The contact thermometer 40 is configured to contact the skin surface and measure its contact temperature and is arranged on the back side of the main body case 10 (the side which contacts the skin surface when the apparatus is mounted on the user 100) in such a way that a sensor surface 401 is exposed. Meanwhile, the radiation thermometer 50 is configured to measure the radiation temperature of the skin surface via the outside air between the skin surface and the radiation thermometer 50 and is arranged in a suitable position inside the main body case 10.
Here, the main body case 10 has a penetration hole 18 vertically penetrating the main body case 10 near the position of arrangement of the radiation thermometer 50 and opening to the external environment, and also has a reflection mirror 19 arranged in the penetration hole 18. The reflection mirror 19 is supported on the inner side of the penetration hole 18 by a support member 191 attached to the sidewall of the penetration hole 18.
Back to
Here, the principle of measuring the quantity of heat of perspiration vaporization using the contact temperature (first temperature) measured by the contact thermometer 40 and the radiation temperature (second temperature) measured by the radiation thermometer 50 will be described. When water evaporates by perspiration from the skin surface 101 of the user 100 as a measuring target, heat of vaporization is taken away and therefore the temperature of the skin surface 101 drops. However, as far as the part of the skin surface 101 in contact with the contact thermometer 40 is concerned, since this part is not in contact with the outside air, water does not evaporate and heat of vaporization is not taken away, and therefore the temperature of the skin surface 101 does not drop. That is, if the contact temperature measured by the contact thermometer 40 is Ts and the radiation temperature measured by the radiation thermometer 50 is Tr, the relation between the contact temperature Ts and the radiation temperature Tr expressed by the following equation (1) holds.
Ts>Tr (1)
The temperature difference between the contact temperature Ts and the radiation temperature Tr is the temperature difference generated as water evaporates and heat of vaporization is taken away from the skin surface 101, and therefore this temperature different is proportionate to the quantity of heat of perspiration vaporization. The relation between the temperature difference and the quantity of heat of perspiration vaporization can be expressed by the following equation (2), where Q [W] is the quantity of heat of perspiration vaporization per unit time and K is a predetermined constant of proportionality.
Q=K(Ts−Tr) (2)
Therefore, the quantity of heat of perspiration vaporization Q can be calculated, that is, measured on the basis of the contact temperature Ts and the radiation temperature Tr, for example, according to the equation (2).
However, the method for measuring the quantity of heat of perspiration vaporization is not limited to this. For example, a true value of the quantity of heat of perspiration vaporization is actually measured by a heat analyzer or the like, and at the same time, the contact temperature and the radiation temperature is measured so as to acquire the relation between the quantity of heat of vaporization, and the contact temperature and the radiation temperature, in advance. When the electronic apparatus 1 is in use, the quantity of heat of perspiration vaporization Q may be calculated by regression analysis based on the contact temperature Ts measured by the contact thermometer 40 and the radiation temperature Tr measured by the radiation thermometer 50. In this case, the quantity of heat of perspiration vaporization Q is calculated on the basis of the linear sum of the contact temperature Ts and the radiation temperature Tr according to the following equation (3), where S and R are predetermined constants of proportionality and D1 is a predetermined constant.
Q=S×Ts+R×Tr+D1 (3)
Alternatively, the quantity of heat of perspiration vaporization Q may be calculated by multiple regression analysis based on the contact temperature Ts measured by the contact thermometer 40 and the radiation temperature Tr measured by the radiation thermometer 50. In this case, the quantity of heat of perspiration vaporization Q is calculated on the basis of the sum of squares of the contact temperature Ts and the radiation temperature Tr according to the following equation (4), where S1, S2, R1 and R2 are predetermined constants of proportionality and D2 is a predetermined constant.
Q=S1×Ts+S2×Ts2+R1×Tr+R2×Tr2+D2 (4)
The thermometer unit 30 has a contact-type temperature measuring element 41, an amplifier 43, and an AD converter 45, as the configuration of the contact thermometer 40, as shown in
The thermometer unit 30 also has an infrared condensing lens 51, a radiation temperature measuring element 53, amplifier 55, and an AD converter 57, as the configuration of the radiation thermometer 50. The infrared condensing lens 51 condenses infrared rays from the skin surface 101 and makes the condensed infrared rays incident on the radiation temperature measuring element 53. Although not illustrated in
The operation unit 71 is materialized by various switches such as a button switch, lever switch and dial switch, and an input device such as a touch panel, and outputs an operation signal corresponding to an operation input to the processing unit 77. For example, the operation switch 11 and the touch panel 12 shown in
The display unit 73 is materialized by a display device such as an LCD (liquid crystal display) or EL (electroluminescence display), and displays various screens based on display signals inputted from the processing unit 77. In
The communication unit 75 is a communication device for transmitting and receiving information used inside the device to and from an external information processing device, under the control of the processing unit 77. The communication device 13 in
The processing unit 77 is a control device and computing device which centrally controls each part of the electronic apparatus 1, and is materialized by a microprocessor such as a CPU (central processing unit) or GPU (graphic processing unit), and an ASIC (application specific integrated (integrated circuit) memory or the like. In
The storage unit 79 is materialized by a storage medium including various IC memories such as a ROM (read only memory), flash ROM, and RAM (random access memory), and a hard disk or the like, and suitably includes a device for reading and writing data according to need. In
In this vaporization heat quantity measurement processing, the vaporization heat quantity calculating unit 771 first acquires the contact temperature Ts from the contact thermometer 40 (Step S11) and acquires the radiation temperature Tr from the radiation thermometer 50 (step S13).
Then, the vaporization heat quantity calculating unit 771 executes computing processing of substituting the contact temperature Ts acquired in Step S11 and the radiation temperature Tr acquired in Step S13 in the equation (2) and thus calculating the quantity of heat of perspiration vaporization Q, as vaporization heat quantity computing processing (Step S15). Computing processing using the equation (3) or the equation (4) or the like to calculate the quantity of heat of perspiration vaporization Q may be executed as vaporization heat quantity computing processing. The quantity of heat of perspiration vaporization Q calculated here is displayed on the display unit 73 according to need.
As described above, according to the first embodiment, the quantity of heat of perspiration vaporization can be calculated using the contact temperature and the radiation temperature measured as the temperature of the skin surface of the user 100, and the quantity of heat of perspiration vaporization from the user 100 can be measured. Thus, even in environments where perspiration occurs, for example, at the time of exercise or in a hot environment or the like, the quantity of heat of perspiration vaporization can be measured accurately.
In the first embodiment, the case where the measuring target is a human body whose quantity of heat of perspiration vaporization is measured is described. However, the technique can similarly applied to the case where the measuring target is other animals than human and where the quantity of heat of vaporization due to perspiration of the animals is measured, or the case where the measuring target is an object which generates heat of vaporization (for example, a vegetable or fruit) and where the quantity of heat of vaporization from the object is measured.
The internal configuration of the thermometer unit 30 is not limited to the configuration shown in
Meanwhile, the measurement of the quantity of heat of perspiration vaporization according to the first embodiment is configured on the assumption that a temperature difference occurs between the contact temperature and the radiation temperature of the skin surface due to perspiration (more specifically, the radiation temperature is lower than the contact temperature). In order to confirm this assumption, an experiment to prove that a temperature difference occurs between the contact temperature and the radiation temperature due to the heat of vaporization being taken away from the surface of a measuring target is carried out. In the experiment, a thermostatic chamber is prepared as a heat source and a nonwoven fabric impregnated with water is used as a measuring target. Specifically, while the nonwoven fabric is heated stepwise (for example, by 2[° C.] each) within the range of 37.0[° C.] to 45.0[° C.] by controlling the temperature of the thermostatic chamber, the contact thermometer is brought in contact with a part of the nonwoven fabric and the contact temperature is thus measured, and at the same time, the surface temperature of the nonwoven fabric is remotely measured as the radiation temperature, using thermography.
Next, a second embodiment will be described. In the second embodiment, the metabolic rate due to perspiration of the user 100 is measured, using the quantity of heat of perspiration vaporization found in the first embodiment. In the description below, the same components as in the configuration of the first embodiment are denoted by the same reference numbers.
If the quantity of heat of perspiration vaporization is expressed by Qsw, the metabolic rate due to perspiration Csw can be found by multiplying the quantity of heat of perspiration vaporization Qsw by a predetermined constant of proportionality Ka, as expressed by the following equation (5).
Csw=Ka×Qsw (5)
The constant of proportionality Ka varies depending on the site for measuring the quantity of heat of perspiration vaporization and its surface area, and also depending on the measuring conditions such as the weight, height, age and gender of the user 100. The degree of perspiration (quantity of perspiration) varies from one part to another of the entire body and also changes according to the weight or the like of the user 100. Thus, parent sets in which the measuring conditions such as weight are different are selected, for example. Then, the quantity of heat of perspiration vaporization is measured by the method according to the first embodiment, for example, and at the same time, the true value of the metabolic rate is actually measured by a respiratory gas analyzer. Based on this statistical value, the constant of proportionality Ka is found for each parent set. Thus, the constant of proportionality Ka corresponding to the measuring conditions is set in advance. When an electronic apparatus 1b (see
In the second embodiment, the processing unit 77b includes a vaporization heat quantity calculating unit 771, and a metabolic rate calculating unit 772b which calculates the metabolic rate due to perspiration, using the quantity of heat of perspiration vaporization. In the storage unit 79b, a second measurement program 791b for causing the processing unit 77b to function as the vaporization heat quantity calculating unit 771 and the metabolic rate calculating unit 772b and execute metabolic rate measurement processing is stored.
In this metabolic rate measurement processing, following Step S15, the metabolic rate calculating unit 772b substitutes the quantity of heat of perspiration vaporization Q calculated in Step S15 as Qsw in the equation (5) and thus calculates the metabolic rate due to perspiration Csw (Step S17). The metabolic rate due to perspiration Csw calculated here is displayed on the display unit 73 together with the quantity of heat of perspiration vaporization Q (Qsw) according to need.
As described above, according to the second embodiment, the metabolic rate due to perspiration of the user 100 can be measured, using the quantity of heat of perspiration vaporization found by measuring the contact temperature and the radiation temperature of the skin surface of the user 100.
Next, a third embodiment will be described. In the description below, the same components as in the configuration according to the second embodiment are denoted by the same reference numbers.
In the second embodiment, the metabolic rate due to perspiration is found on the basis of the quantity of heat of perspiration vaporization measured at one measuring site. However, if the quantity of heat of perspiration vaporization is measured at different measuring sites on the user 100, the metabolic rate due to perspiration can be measured with higher accuracy. The metabolic rate due to perspiration Csw in this case is expressed by the following equation (6).
Csw=Kb1×Qsw1+Kb2×Qsw2+ . . . +Kbn×Qswn (6)
Here, in the equation (6), Qsw1, Qsw2, . . . , Qswn represent the quantities of heat of perspiration vaporization Qsw at the measuring sites identified by the added numbers 1, 2, . . . , n. Also, Kb1, Kb2, . . . , Kbn represent predetermined constants of proportionality set in advance for the respective measuring sites identified by the added numbers 1, 2, . . . , n. The reason for setting the constants of proportionality Kb1, Kb2, . . . , Kbn for the respective measuring sites is that the degree of perspiration varies from one site to another on the entire body and also changes according to the surface area or the like of the measuring site. For example, the quantity of heat of perspiration vaporization is measured at each measuring site by the method according to the first embodiment, and at the same time, the true value of the metabolic rate is actually measured by a respiratory gas analyzer. Then, multivariate analysis such as multiple regression analysis is performed, thus finding and setting the constants of proportionality Kb1, Kb2, . . . , Kbn.
The plurality of thermometer units 30 (301, 2, . . . , n) are mounted at different measuring sites on the user 100 and measure the contact temperature Ts and the radiation temperature Tr on the skin surface. The configuration of each individual thermometer unit 30 can be formed similarly to the configuration described in the first embodiment. As a specific method for materialization, for example, apart from the electronic apparatus 1c having one thermometer unit 30 similarly to the apparatus shown in
The processing unit 77c includes a vaporization heat quantity calculating unit 771c and a metabolic rate calculating unit 772c. In the storage unit 79c, a third measurement program 791c is stored.
In the metabolic rate measurement processing according to the third embodiment, first, the vaporization heat quantity calculating unit 771c acquires the contact temperature Ts measured by each contact thermometer 40 at each measuring site (Step S201) and also acquires the radiation temperature Tr measured by each radiation thermometer 50 at each measuring site (Step S203).
Subsequently, the vaporization heat quantity calculating unit 771c executes processing of loop B, sequentially taking the measuring sites where the respective thermometer units 30 are installed, as processing target sites (Step S205 to Step S209). That is, in the loop B, the vaporization heat quantity calculating unit 771c calculates the quantity of heat of perspiration vaporization Q at the processing target site, for example, according to the equation (2) using the contact temperature Ts and the radiation temperature Tr acquired from the contact thermometer 40 and the radiation thermometer 50 at the processing target site in Step S201 and Step S203 (Step S207).
Then, after the quantities of heat of perspiration vaporization Q at all the measuring sites are calculated, the metabolic rate calculating unit 772c substitutes the quantity of heat of perspiration vaporization Q at each measuring site calculated in Step S207, as Qsw1, Qsw2, . . . , Qswn in the equation (6) and thus calculates the metabolic rate due to perspiration Csw (Step S211). The metabolic rate due to perspiration Csw calculated here is displayed on the display unit 73 together with the quantity of heat of perspiration vaporization Q (Qsw1, Qsw2, . . . , Qswn) at each measuring site according to need.
As described above, according to the third embodiment, the quantity of heat of perspiration vaporization is measured at different measuring sites on the user 100, and the metabolic rate to due perspiration can be calculated from the quantity of heat of perspiration vaporization at each measuring site. Therefore, the accuracy of measurement of the metabolic rate due to perspiration of the user 100 is improved.
Next, a fourth embodiment will be described. In the fourth embodiment, the metabolic rate due to heat flow is calculated apart from the metabolic rate due to perspiration, and the total metabolic rate of the user 100 is measured. In the description below, the same components as in the configuration according to the third embodiment are denoted by the same reference numbers.
Heat dissipation from a human body includes heat dissipation generated by the perspiration function (evaporative heat loss) and heat dissipation due to heat transfer (convection), radiation of electromagnetic waves, and the like (non-evaporative heat loss). Therefore, the metabolic rate can be measured with higher accuracy by taking both into account.
The heat dissipation from a human body due to heat transfer and the like can be measured as a heat flow generated on the skin surface of the user 100. For example, in the case of measuring the heat flow at a plurality of measuring sites, the metabolic rate due to heat flow Cc can be found by the following equation (7).
Cc=L1×Qc1+L2×Qc2+ . . . +Ln×Qcn (7)
Here, in the equation (7), Qc1, Qct, . . . , Qcn represent the heat flows Qc identified by the added numbers 1, 2, . . . , n. L1, L2, . . . , Ln represent constants of proportionality set in advance for the respective measuring sites identified by the added numbers 1, 2, . . . , n. The reason for setting the constants of proportionality L1, L2, . . . , Ln for the respective measuring sites is that the heat dissipation from the human body due to heat transfer is not uniform at each site on the entire body and also varies depending on the area of the measuring site and the like. For example, the true value of the metabolic rate is actually measured by a respiratory gas analyzer, and at the same time, the heat flow at each measuring site is measured. Then, multivariate analysis such as multiple regression analysis is performed. The constants of proportionality L1, L2, . . . , Ln are thus found and set.
The total metabolic rate C can be found by the following equation (8) based on the metabolic rate due to perspiration Csw and the metabolic rate due to heat flow Cc. In the equation (8), Asw and Ac are predetermined constants of proportionality.
C=AswCsw+AcCc (8)
The plurality of thermometer units 30 (30-1, 2, . . . , n) measure the contact temperature Ts and the radiation temperature Tr of the skin surface at different measuring sites on the user 100. Meanwhile, the plurality of heat flow meters 60 (60-1, 2, . . . , n) measure the heat flows Qc1, Qc2, . . . , Qcn generated on the skin surface at different measuring sites on the user 100. As a specific method for implementation, for example, the electronic apparatus 1d having one thermometer unit 30 as in the configuration described in
The processing unit 77d includes a vaporization heat quantity calculating unit 771c and a metabolic rate calculating unit 772d. The metabolic rate calculating unit 772d includes a first metabolic rate calculating unit 773d which calculates the metabolic rate due to perspiration, and a second metabolic rate calculating unit 774d which calculates the metabolic rate to heat flow, using the heat flows Qc1, Qc2, . . . , Qcn inputted from the heat flow meters 60 at the respective measuring sites. The metabolic rate calculating unit 772d thus calculates the total metabolic rate based on the metabolic rate due to perspiration and the metabolic rate due to heat flow. In the storage unit 79d, a fourth measurement program 791d is stored.
In the metabolic rate calculation processing according to the fourth embodiment, after Step S203, the metabolic rate calculating unit 772d acquires the heat flows Qc1, Qc2, . . . , Qcn from the plurality of heat flow meters 60 (step S204).
After the processing of loop B, the first metabolic rate calculating unit 773d calculates the metabolic rate due to perspiration Csw according to the equation (6) (Step S211). Subsequently, the second metabolic rate calculating unit 774d substitutes the heat flows Qc1, Qc2, . . . , Qcn at the respective measuring sites acquired in Step S204, in the equation (7), and thus calculates the metabolic rate due to heat flow Cc (step S213). Then, the metabolic rate calculating unit 772d substitutes the metabolic rate due to perspiration Csw calculated in Step S211 and the metabolic rate due to heat flow Cc calculated in Step S213, in the equation (8), and thus calculates the total metabolic rate C (Step S215). The total metabolic rate C calculated here is displayed on the display unit 73 together with the quantities of heat of perspiration vaporization Q (Qsw1, Qsw2, . . . , Qswn) at the respective measuring sites calculated in Step S207, the metabolic rate due to perspiration Csw and the metabolic rate due to heat flow Cc, according to need.
As described above, according to the fourth embodiment, the heat flow generated in the skin surface is measured at different measuring sites on the user 100, and the metabolic rate due to heat flow of the user 100 can be calculated. Then, the total metabolic rate can be calculated on the basis of the metabolic rate due to perspiration and the metabolic rate due to heat flow. Thus, the total metabolic rate can be found, taking into account not only the heat dissipated as heat of vaporization from the skin surface due to perspiration but also the heat dissipated from the skin surface due to heat transfer or the like. Therefore, the metabolic rate of the user 100 can be measured with higher accuracy.
While the case of measuring the quantity of heat of perspiration vaporization and the heat flow at a plurality of measuring sites is described in the fourth embodiment, a single measuring site may be used. That is, the metabolic rate due to perspiration may be found on the basis of the quantity of heat of perspiration vaporization measured at a single measuring site, and the metabolic rate due to heat flow may be found on the basis of the heat flow measured at a single measuring site, so as to calculate the total metabolic rate.
In the embodiments, the measurement of the quantity of heat of perspiration vaporization, and the measurement of the metabolic rate using the quantity of heat of perspiration vaporization and the heat flow are described. However, it is also possible to measure biological information other than metabolic rate, for example, to find the calories burned, using the quantity of heat of perspiration vaporization and the heat flow, or to measure the functions of autonomic nerves of the human body.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-020899 | Feb 2015 | JP | national |
