JP2017196474A - Dewatering state determination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always determine a dewatering state, without putting a burden on a subject.SOLUTION: A dewatering state determination device comprises blood flow measurement means for measuring a blood flow, by receiving return light of a laser beam radiated to a wrist of a subject, and analyzing the return light. When the subject raises his/her hand and then rests at a certain vertical interval h, following to temporary reduction of the blood flow, then the reverse to increase of the blood flow, and recovery to a constant blood flow, the dewatering state determination device measures a recovery blood flow BFr and a blood flow recovery time Tr since reverse until recovery, then divides the recovery blood flow BFr by the blood flow recovery time Tr, for calculating a blood flow recovery gradient H. The dewatering state determination device determines whether or not a state of the subject is a dewatering state, according to whether or not a water content ratio reduction degree Rm obtained by dividing a reference blood flow recovery gradient Hs calculated following to preliminary measurement during normal state time of the subject, by a blood flow gradient Hp calculated following to measurement in normal time of the same subject, is equal to or more than a prescribed reduction degree threshold, and if it is determined that the state is the dewatering state, outputs voice of a hydration message, for promoting intake of moisture content to the subject.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a dehydration state determination device for determining a dehydration state.

  Dehydration is a condition in which water in the living body decreases, and it often develops on a daily basis.In particular, dehydration is a condition that occurs frequently during exercise or when the temperature is high, when a large amount of water is discharged from the body due to sweating or an increase in body temperature. is there. It is known that dehydration increases the risk of heat stroke, cerebral infarction and myocardial infarction even in the absence of subjective symptoms.

  Conventionally, a dehydration state determination device for easily knowing dehydration symptoms in daily life has been considered. This conventional dehydration state determination device measures the bioelectrical impedance value by applying an alternating current to the body of the measured person, and determines the dehydrated state of the measured person based on the measured bioelectrical impedance value. is there. In this device, in order to ensure that the person to be measured inspects the dehydration state at an appropriate timing without forgetting, the person to be measured urges the person to hold the device body with both hands by sounding a buzzer at a predetermined time. The dehydration state is determined by measuring the bioelectric impedance value (see, for example, Patent Document 1).

JP 2002-034946 A

  In the conventional dehydration state determination device, the measurement subject must measure a bioelectrical impedance value in response to a buzzer that rings at a predesignated time in order to reliably inspect the dehydration state without forgetting it. There was inconvenience.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a dehydration state determination apparatus that can always determine a dehydration state without imposing a burden on the measurement subject. .

  The dehydration state determination apparatus according to the present invention includes a blood flow measuring unit that measures a blood flow of a part of the subject, a position detecting unit that detects a change in the position of the part of the subject, and a position detecting unit. A blood flow recovery measuring means for measuring a recovery state of the blood flow measured by the blood flow measuring means when a change in the position of the measurement subject's part is detected; And a water content determining means for determining whether the dehydrated state is based on the recovered state of the blood flow.

  According to the present invention, it is possible to always determine the dehydration state without imposing a burden on the measurement subject.

The front view which shows the external appearance structure of the wristwatch type dehydration state determination apparatus 10 which concerns on embodiment of the dehydration state determination apparatus of this invention. FIG. 3 is a plan view showing a back configuration of the wrist watch type dehydrated state determining apparatus 10. It is a figure explaining the method to determine a dehydration state by the said dehydration state determination apparatus 10, and shows the change of the blood flow rate of the wrist from after raising a to-be-measured person to after raising a hand. The block diagram which shows the function of each part comprised by the electronic circuit and software containing CPU of the said dehydration state determination apparatus. 3 is a flowchart showing an overall flow of a dehydration state determination process performed by the dehydration state determination apparatus 10; 4 is a flowchart showing a preliminary measurement process SA by the dehydration state determination apparatus 10. 5 is a flowchart showing a normal measurement process SB by the dehydration state determination device 10.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a front view showing an external configuration of a wristwatch-type dehydrated state determining apparatus 10 according to an embodiment of the dehydrated state determining apparatus of the present invention.

  FIG. 2 is a plan view showing a rear configuration of the wristwatch type dehydrated state determining apparatus 10.

  As shown in FIG. 1, the wristwatch type dehydration state determination device 10 is used by being worn on the wrist of a human body N, for example, and includes a display unit 11 that displays time, blood pressure, dehydration state determination results, and the like.

  Further, as shown in FIG. 2, a light output hole 12a and a light input hole 12b are formed adjacent to each other on the back surface 10B of the wristwatch-type dehydrated state determination device 10, and a laser beam is formed behind the light output hole 12a. Is disposed on the back of the light input hole 12b, and a photodiode for receiving the return light of the irradiated laser light from the human body N is disposed.

  The laser light is scattered while maintaining the frequency by a stationary biological tissue such as skin or subcutaneous tissue. On the other hand, light scattered by blood cells mainly consisting of red blood cells moving in blood vessels undergoes a slight amount of wavelength shift according to the moving speed. The return light is accompanied by a beat caused by interference between the two types of scattered light. In the dehydration state determination apparatus 10, the blood flow is calculated by analyzing the beat component of the return light received by the photodiode.

  Specifically, fast Fourier transform (FFT) is performed on the output signal of the photodiode, the frequency is weighted, and integration is performed in an appropriate frequency range to calculate the first moment. The calculated first moment is multiplied by a proportionality constant, normalized by the total power of the received light signal so as not to depend on the received light intensity of the laser beam, and the blood flow is calculated.

  FIG. 3 is a diagram for explaining a method of determining the dehydration state by the dehydration state determination apparatus 10, and shows a change in the blood flow rate of the wrist from before raising the hand of the measurement subject to after raising the hand.

  When the hand is hung from the body side to a certain height and stopped still, the blood flow rate once decreases, but eventually it rises and recovers. As time further elapses, the blood flow becomes almost constant at a certain point.

  The time from when the blood flow starts to rise until it becomes constant is measured. This is defined as a blood flow recovery time Tr. Next, the difference between the blood flow rate BF1 when the blood flow rate starts to rise and the blood flow rate BF2 when the blood flow rate becomes constant is measured. This is defined as a recovery blood flow rate BFr. Further, a blood flow recovery gradient H is obtained by dividing the recovered blood flow rate BFr by the blood flow recovery time Tr.

  When the measurement subject falls into a dehydrated state, the water ratio in the blood decreases, so that the blood flow rate decreases compared to a normal state, and the recovery rate of the blood flow rate after raising the hand becomes dull.

  Therefore, the blood flow recovery gradient H corresponding to the blood flow volume A in the normal state of the measurement subject is measured and recorded in advance as the reference blood flow recovery gradient Hs, and the recorded reference blood flow recovery gradient Hs is thereafter recorded. When the ratio divided by the blood flow recovery gradient Hp corresponding to the measured blood flow B of the same subject is equal to or greater than a predetermined threshold, it can be determined that the subject is dehydrated.

  Note that when the difference in height h between the wrist before raising and after raising the hand becomes smaller, the blood flow recovery gradient H also becomes smaller. Therefore, in this embodiment, the height difference h0 associated with the measurement in the normal state of the subject and the subsequent height difference h0. Based on the ratio with the height difference h1 associated with the measurement, the blood flow recovery gradient Hp at the time of dehydration determination is corrected.

  FIG. 4 is a block diagram showing the function of each part constituted by an electronic circuit including the CPU of the dehydration state determination apparatus 10 and software.

  The dehydration state determination apparatus 10 includes an optical measurement unit 21, an acceleration measurement unit 22, and a timer unit 23.

  The optical measurement unit 21 includes a laser diode that irradiates laser light to the human body N through the light output hole 12a, a photodiode that receives return light through the light input hole 12b, and an amplification unit that amplifies the light reception signal of the photodiode. And the light reception signal of the return light amplified by the amplification unit is output to the blood flow rate calculation unit 24.

  The acceleration measuring unit 22 includes a triaxial acceleration sensor, and outputs an acceleration value in the triaxial direction detected by the acceleration sensor to the position estimating unit 25.

  The time measuring unit 23 has a time measuring circuit for date and time, and outputs the time measuring signal to a clock processing unit (not shown) and to the blood flow change pattern determining unit 26.

  The blood flow rate calculation unit 24 receives the return light reception signal output from the optical measurement unit 21 and, as described above, calculates the blood flow rate by analyzing the beat component included in the return light. The obtained blood flow is output to the blood flow change pattern determination unit 26.

  The position estimation unit 25 receives the acceleration value output from the acceleration measurement unit 22, integrates the input acceleration value to calculate the position of the apparatus body, and determines the calculated position of the apparatus body as a blood flow change pattern determination. To the unit 26.

  The blood flow change pattern determination unit 26 receives the blood flow output from the blood flow calculation unit 24, the position of the apparatus main body output from the position estimation unit 25, and the time measurement signal output from the time measurement unit 23. The blood flow change pattern is determined by measuring the recovery blood flow rate BFr, the blood flow recovery time Tr, the blood flow recovery gradient H, and the height difference h of the apparatus body. Each measurement data measured by the blood flow change pattern determination unit 26 is selectively output to the blood flow change pattern recording unit 27 and the water content determination unit.

  The blood flow change pattern recording unit 27 calculates the blood flow recovery gradient H measured by the blood flow change pattern determination unit 26 and the height difference h of the apparatus main body in accordance with the preliminary measurement process performed by the measurement subject in a normal state. Record as the reference blood flow recovery gradient Hs and the reference height difference h0. The reference blood flow recovery gradient Hs and the reference height difference h0 recorded by the blood flow change pattern recording unit 27 are output to the water content determination unit 28 along with the normal measurement process of the measurement subject.

  Based on the reference blood flow recovery gradient Hs input from the blood flow change pattern recording unit 27 and the blood flow recovery gradient Hp in the normal measurement process input from the blood flow change pattern determination unit 26, the water amount determination unit 28 The moisture ratio Rm in the inside is calculated, and it is determined whether or not it is in a dehydrated state based on whether or not the calculated moisture ratio Rm is equal to or greater than a predetermined threshold value.

  At this time, the altitude correction index C is calculated by dividing the height difference h1 in the normal measurement process input from the blood flow change pattern determination unit 26 by the reference height difference h0 input from the blood flow change pattern recording unit 27, The corrected blood flow recovery gradient Hc is calculated by dividing the blood flow recovery gradient Hp by the altitude correction index C. Then, the reference blood flow recovery gradient Hs is divided by the corrected blood flow recovery gradient Hc to calculate an accurate water ratio Rm in the blood of the subject, and it is determined whether or not the subject is dehydrated. To do.

  The message creation unit 29 creates a message to be output from the voice output unit 30 according to the determination result of whether or not the measurement subject input from the moisture amount determination unit 28 is in a dehydrated state.

  The voice output unit 30 outputs the message created by the message creation unit 29 to the outside as voice.

  In the dehydration state determination apparatus 10 configured as described above, the CPU controls the operation of each part of the circuit in accordance with various processing instructions described in the control program of the determination apparatus, and the software and hardware cooperate. The various functions described in the following operation explanation are realized.

  Next, the operation of the wristwatch type dehydrated state determining apparatus 10 having the above-described configuration will be described.

  FIG. 5 is a flowchart showing the overall flow of the dehydration state determination process by the dehydration state determination device 10.

  In this dehydration state determination process, first, the preliminary measurement process (step SA) is executed while the measurement subject is in a normal state, and thereafter the normal measurement process (step SB) is always executed.

  FIG. 6 is a flowchart showing the preliminary measurement process SA by the dehydration state determination apparatus 10.

  The measurement subject performs this preliminary measurement process SA in a state where water is sufficiently ingested, for example, within a predetermined time after eating.

  When the preliminary measurement process is started in response to a user operation of the apparatus main body, a voice of a hand lowering request message “Please drop your hand to the body side” created in advance by the message creation unit 29 is output from the voice output unit 30. (Step A1). In response to the hand lowering request message, the person to be measured keeps his / her hand wearing the dehydrated state determination apparatus 10 in a state where it is hung on the body side.

  When it is detected that the apparatus main body is stationary by eliminating the change in the acceleration value measured by the acceleration measuring unit 22 (step A2 (Yes)), the return light from the human body N output by the optical measuring unit 21 Based on the received light signal, measurement (calculation) of the blood flow BF by the blood flow calculation unit 24 is started (step A3).

  Then, the voice output unit 30 outputs a voice of a hand raising request message “Please raise your wrist to the shoulder level and stop” (step A4). When the person to be measured raises his / her hand according to the hand raising request message and stops, the change in the acceleration value measured by the acceleration measuring unit 22 is eliminated, thereby detecting that the apparatus main body is stationary (step A5). (Yes)).

  Here, the blood flow change pattern determination unit 26 calculates the height difference h based on the position of the apparatus main body before and after raising the hand output from the position estimation unit 25, and the blood flow change pattern recording unit as the reference height difference h0. 27 (step A6).

  When the measurement subject's hand is raised, as shown in FIG. 3, the blood flow rate BF temporarily decreases, but eventually the blood flow rate BF starts to increase and the blood flow rate BF starts to recover. As time further elapses, the blood flow BF of the measurement subject becomes almost constant at a certain point.

  When it is determined that the blood flow BF is reversed in the recovery direction based on the change in the blood flow BF output from the blood flow calculation unit 24 (step A7 (Yes)), the time measurement signal output from the time measurement unit 23. Based on the above, the blood flow change pattern determination unit 26 starts measuring the time from the time when the blood flow is reversed (step A8).

  Thereafter, when it is determined that the blood flow BF is substantially constant based on the change in the blood flow BF output from the blood flow calculation unit 24 (step A9 (Yes)), from the time when the blood flow is reversed. Is measured and the elapsed time is recorded as the blood flow recovery time Tr (step A10).

  Then, the difference between the blood flow rate BF1 at the time of inversion of the blood flow rate BF measured (calculated) by the blood flow rate calculation unit 24 and the blood flow rate BF2 at the time when the blood flow rate becomes constant is calculated as the recovery blood flow rate BFr. . Then, the recovered blood flow rate BFr is divided by the blood flow recovery time Tr to calculate a blood flow recovery gradient H, which is recorded in the blood flow change pattern recording unit 27 as a reference blood flow recovery gradient Hs (step A11).

  Then, the voice output unit 30 outputs the voice of the end message “Measurement is finished”.

  As a result, the blood flow change pattern recording unit 27 records the reference blood flow recovery gradient Hs and the reference height difference h0 associated with the preliminary measurement process in a normal state of the measurement subject.

  FIG. 7 is a flowchart showing the normal measurement process SB by the dehydration state determination apparatus 10.

  This normal measurement process SB is always performed daily after the preliminary measurement process SA.

  When it is determined that the apparatus main body is not stationary according to the acceleration value measured by the acceleration measuring unit 22, that is, the movement of the apparatus main body is detected, and the person to be measured is moving while wearing the apparatus main body ( Step B1 (No)), measurement (calculation) of the blood flow BF by the blood flow calculation unit 24 is started based on the received light signal of the return light from the human body N output by the optical measurement unit 21 (Step B2). .

  Further, according to the acceleration value measured by the acceleration measuring unit 22, the moving distance in the vertical direction accompanying the ascent of the apparatus body while the measurement subject moves is calculated (step B3), and the moving distance is a predetermined value. It is determined whether or not the above has been reached (step B4).

  If it is determined that the moving distance that accompanies the rise of the apparatus main body is equal to or greater than a predetermined value and the hand is raised above a preset height difference (step B4 (Yes)), then the acceleration measuring unit 22 It is determined whether there is no change in the measured acceleration value and the apparatus main body is stationary (step B5).

  If it is determined that the main body of the apparatus is stationary (step B5 (Yes)), the height difference h1 in the normal measurement process SB, the recovery blood flow BFr, and the blood flow are similar to the operation in the preliminary measurement process SA. The recovery time Tr is measured (calculated) (steps B6 to B10).

  Then, the measured recovery blood flow BFr of the measured person is divided by the blood flow recovery time Tr to calculate a blood flow recovery gradient Hp (step B11), and the reference height difference recorded with the preliminary measurement process SA is calculated. Correction processing of the blood flow recovery gradient Hp based on h0 and the current height difference h1 is executed (step BH).

  In the correction process BH, first, the altitude correction index C is calculated by dividing the height difference h1 associated with the current normal measurement process SB by the reference height difference h0 associated with the preliminary measurement process SA (step BH1).

  Then, the blood flow recovery gradient Hp associated with the current normal measurement process SB is divided by the altitude correction index C to calculate a corrected blood flow recovery gradient Hc (step BH2).

  Then, in the water content determination unit 28, the reference blood flow recovery gradient Hs recorded in the blood flow change pattern recording unit 27 is divided by the corrected blood flow recovery gradient Hc, and the current water ratio decrease degree Rm of the measurement subject is obtained. Is calculated (step B12).

  Then, it is determined whether or not the dehydration state is present based on whether or not the moisture ratio decrease degree Rm is equal to or greater than a predetermined decrease degree threshold (step B13). If it is determined that the dehydration state is present (step B13). (Yes)), a hydration message for prompting the subject to take water is created by the message creation unit 29, and is output as voice from the voice output unit 30 (step B14).

  Specifically, for example, when the height difference h1 associated with the current normal measurement process SB is 30 cm and the height difference h0 associated with the preliminary measurement process SA is 60 cm, the height correction index C = h1 / h0 = 0.5 Become. If the blood flow recovery gradient Hp associated with the normal measurement process SB is “0.7”, the corrected blood flow recovery gradient Hc divided by the altitude correction index C = 0.5 is Hc = Hp / C = 1.4. If the reference blood flow recovery gradient Hs accompanying the preliminary measurement process SA is “2”, the water ratio reduction degree Rm = Hs / Hc = 2 / 1.4 = 1.43. When the moisture ratio reduction degree Rm = 1.43 is greater than or equal to a predetermined reduction degree threshold value, the moisture supply message is output.

  On the other hand, when it is determined that the moisture ratio lowering degree Rm is not dehydrated because it is less than a predetermined lowering degree threshold (step B13 (No)), the normal measurement process SB is repeatedly executed, Without being aware of the person, it is always determined whether or not it is in a dehydrated state (steps B13 → B1 to B13). And when it determines with it being a dehydration state, the said hydration message is output immediately (step B13 (Yes))-> B14).

  Therefore, according to the wristwatch-type dehydrated state determination device 10 having the above-described configuration, the blood flow measuring means for receiving the return light of the laser light irradiated on the wrist of the person to be measured and measuring the blood flow by analyzing the return light. When the person to be measured stands still with his hand raised at a certain height difference h, the blood flow decreases temporarily, reverses to increase, and recovers to a constant level. The blood flow recovery time Tr is measured, and the blood flow recovery gradient H is calculated by dividing the recovered blood flow rate BFr by the blood flow recovery time Tr. The water ratio decrease degree Rm obtained by dividing the reference blood flow recovery gradient Hs calculated with the measurement subject's normal preliminary measurement by the blood flow recovery gradient Hp calculated with the measurement subject's normal measurement, It is determined whether or not it is in a dehydrated state depending on whether or not it is equal to or greater than a predetermined decrease degree threshold value. If it is determined that it is in a dehydrated state, a hydration message is output as a voice to encourage water intake.

  For this reason, after performing the preliminary measurement when the measurement subject is normal, the water content in the blood can be constantly monitored and the hydration can be appropriately promoted without imposing a burden on the measurement subject. This can prevent heat stroke. Moreover, since the blood viscosity can be maintained appropriately, risks such as economy syndrome and circulatory system disorder during sleep can be reduced.

  Further, according to the wristwatch-type dehydration state determination apparatus 10 having the above-described configuration, the wrist height difference h accompanying the preliminary measurement when the measurement subject is normal is recorded as the reference height difference h0, and the reference height difference h0 is normally recorded. The altitude correction index C divided by the height difference h1 is calculated. The normal blood flow recovery gradient Hp is divided by the altitude correction index C to obtain a corrected blood flow recovery gradient Hc, and the reference blood flow recovery gradient Hs is divided by the corrected blood flow recovery gradient Hc to obtain high accuracy. A water content ratio reduction degree Rm is calculated.

  For this reason, the person to be measured can receive a determination as to whether or not the dehydration state is more accurately than usual without any awareness.

  In the above-described embodiment, an optical sensor in which a laser diode and a photodiode are arranged is used for blood flow measurement, but blood flow measurement may be performed using an ultrasonic sensor instead of the optical sensor.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention when it is practiced. Further, each of the embodiments includes inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent elements are deleted from all the constituent elements shown in each embodiment or some constituent elements are combined in different forms, the problems described in the column of the problem to be solved by the invention If the effects described in the column “Effects of the Invention” can be obtained, a configuration in which these constituent requirements are deleted or combined can be extracted as an invention.

  Hereinafter, the invention described in the scope of claims of the present application will be appended.

[1]
A blood flow measuring means for measuring the blood flow of the measurement subject's site;
Position detecting means for detecting a change in the position of the measurement subject's part; and
A blood flow recovery measuring means for measuring a recovery state of the blood flow measured by the blood flow measuring means when a change in the position of the measurement subject's part is detected by the position detecting means;
A water content determination means for determining whether or not the dehydration state based on the recovery state of the blood flow measured by the blood flow recovery measurement means;
A dehydration state determination device comprising:

[2]
The blood flow measurement means is attached to the wrist of the measurement subject, measures the blood flow of the wrist,
The position detecting means detects a change in which the position of the wrist of the person to be measured is raised above a predetermined height difference;
The blood flow recovery measuring means measures the blood flow measured by the blood flow measuring means when the position detecting means detects a change in which the position of the wrist of the person to be measured is raised above a predetermined height difference. Measure the recovery blood flow and recovery time until it recovers to a certain level after it starts to rise after it decreases.
The water content determination means determines whether or not it is dehydrated based on a blood flow recovery gradient calculated from the recovery blood flow measured by the blood flow recovery measurement means and the recovery time,
The dehydration state determination device according to [1], wherein

[3]
The water content determination means includes a reference blood flow recovery gradient calculated from a recovery blood flow and a recovery time measured in advance by the blood flow recovery measurement means, and a blood flow calculated from the recovery blood flow and the recovery time measured this time. Determining the degree of water loss in the blood based on the ratio to the recovery gradient,
The dehydration state determination device according to [2], wherein

[4]
Comprising a height difference measuring means for measuring a height difference in the position of the wrist of the measurement subject detected by the position detecting means,
The water content determination means includes correction index calculation means for calculating a correction index based on the height difference measured in advance by the height difference measurement means and the height difference measured this time, and the reference blood flow recovery gradient Determining the degree of water reduction in the blood based on the ratio with the current blood flow recovery gradient corrected by the correction index calculated by the correction index calculation means,
The dehydration state determination device according to [3], wherein

[5]
The position detection unit includes an acceleration sensor, and detects a change in the position of the measurement subject's part based on an acceleration value output from the acceleration sensor.
The dehydration state determination device according to any one of [1] to [4], wherein

[6]
The blood flow measurement means has an optical sensor, and measures the blood flow of the measurement subject's part based on an output signal from the optical sensor.
The dehydration state determination device according to any one of [1] to [5], wherein

DESCRIPTION OF SYMBOLS 10 ... Watch-type dehydration state determination apparatus N ... Human body 10B ... Apparatus back surface 11 ... Display part 12a ... Light output hole 12b ... Light input hole 21 ... Optical measurement part 22 ... Acceleration measurement part 23 ... Time measurement part 24 ... Blood flow rate calculation part 25 ... Position estimation unit 26 ... Blood flow change pattern determination unit 27 ... Blood flow change pattern recording unit 28 ... Water content determination unit 29 ... Message creation unit 30 ... Voice output unit

The dehydration state determination apparatus according to the present invention is
And blood Nagarehaka constant means for measuring the blood flow region of the subject,
Position detecting means for detecting a change in the position of the measurement subject's part; and
When the change in position of the portion of the measured person is detected by the position detecting means, a blood flow change measuring means for measuring changes in blood flow as measured by the blood Nagarehaka constant means,
And water content determination means for determining whether the dehydration condition based on the change in blood flow as measured by the blood flow change measurement unit,
It is provided with.

Claims (6)

A blood flow measuring means for measuring the blood flow of the measurement subject's site;
Position detecting means for detecting a change in the position of the measurement subject's part; and
A blood flow recovery measuring means for measuring a recovery state of the blood flow measured by the blood flow measuring means when a change in the position of the measurement subject's part is detected by the position detecting means;
A water content determination means for determining whether or not the dehydration state based on the recovery state of the blood flow measured by the blood flow recovery measurement means;
A dehydration state determination device comprising: The blood flow measurement means is attached to the wrist of the measurement subject, measures the blood flow of the wrist,
The position detecting means detects a change in which the position of the wrist of the person to be measured is raised above a predetermined height difference;
The blood flow recovery measuring means measures the blood flow measured by the blood flow measuring means when the position detecting means detects a change in which the position of the wrist of the person to be measured is raised above a predetermined height difference. Measure the recovery blood flow and recovery time until it recovers to a certain level after it starts to rise after it decreases.
The water content determination means determines whether or not it is dehydrated based on a blood flow recovery gradient calculated from the recovery blood flow measured by the blood flow recovery measurement means and the recovery time,
The dehydration state determination device according to claim 1. The water content determination means includes a reference blood flow recovery gradient calculated from a recovery blood flow and a recovery time measured in advance by the blood flow recovery measurement means, and a blood flow calculated from the recovery blood flow and the recovery time measured this time. Determining the degree of water loss in the blood based on the ratio to the recovery gradient,
The dehydration state determination apparatus according to claim 2. Comprising a height difference measuring means for measuring a height difference in the position of the wrist of the measurement subject detected by the position detecting means,
The water content determination means includes correction index calculation means for calculating a correction index based on the height difference measured in advance by the height difference measurement means and the height difference measured this time, and the reference blood flow recovery gradient Determining the degree of water reduction in the blood based on the ratio with the current blood flow recovery gradient corrected by the correction index calculated by the correction index calculation means,
The dehydration state determination apparatus according to claim 3. The position detection unit includes an acceleration sensor, and detects a change in the position of the measurement subject's part based on an acceleration value output from the acceleration sensor.
The dehydration state determination device according to any one of claims 1 to 4, wherein the dehydration state determination device is provided. The blood flow measurement means has an optical sensor, and measures the blood flow of the measurement subject's part based on an output signal from the optical sensor.
The dehydration state determination apparatus according to any one of claims 1 to 5, wherein