JP2011169881A - Apparatus for measuring moisture transpiration amount and body perspiration amount with lapse of time - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small, light-weight and portable device, usable for a long time without obstructing behavior of a subject in measurement of a human body, and measuring a large amount of perspiration in a high humid situation such as in a bathroom or in exercise when measuring the moisture transpiration amount of a surface of an object without using an artificial air flow. <P>SOLUTION: By combining a temperature and humidity sensor and a moisture absorbent (desiccant), the excess moisture after detection is adsorbed to the moisture absorbent, and the humidity in the device is maintained to be low, and the problem is solved. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an apparatus for measuring moisture transpiration on an object surface and sweating of skin over time.

  A sweat meter is an indispensable device for studying the relationship between people and the living environment and clothing environment, and in the industrial field, the amount of transpiration when evaluating the water vapor permeability of sheet materials and the ability to evaporate moisture from the device. Measuring equipment is indispensable.

  In conventional moisture transpiration measurement, a method is used in which a steady air flow is applied to the object to be measured, humidity sensors are placed upstream and downstream of the flow, and the humidity is measured from both sensors. (See “Patent Documents 1 and 2” below.) In principle, measurement is possible with this method, but there are three problems in practice.

  One is that it is difficult to create a steady air flow, the measurement accuracy depends on the continuity, and because mechanical parts such as a pump are necessary, it is difficult to make the device compact and portable. The second problem is that when a large amount of water evaporates like sweat during exercise, the humidity sensor is saturated, resulting in a decrease in measurement accuracy or inability to measure. The third is a mechanism that artificially creates an air flow and takes away water vapor, so it is far from the natural water transpiration phenomenon.

  On the other hand, for a large amount of moisture transpiration, there is a possible countermeasure to heat the humid air with a heater and evaporate it to some extent as in Patent Document 3 below. The problem of rising will also arise.

JP 2001-190502 A

Japanese Patent No. 3711521

  Japanese Patent No. 2600113

Three problems that conventional sweat meter and moisture transpiration meter could not solve,
(1) Long-term unconstrained measurement by eliminating the mechanical parts such as pumps and making them compact, lightweight, and power-saving.
(2) To be able to measure without loss of accuracy even for a large amount of moisture transpiration,
(3) Measure as natural transpiration as possible without using artificial airflow.
To solve.

  First, without using an artificial air flow as in the prior art, a state in which the air is not affected by outside air is created by applying a sealed cup to a measurement object such as skin, and the humidity increase in the cup is monitored by a single humidity sensor.

  However, this alone cannot cope with a large amount of moisture transpiration such as sweating during exercise, and the sensor becomes saturated with water droplets and cannot be measured. Therefore, a method of arranging a moisture absorbent (drying agent) such as silica gel on the upper surface of the cup and absorbing the vapor that has been calibrated by the sensor with the moisture absorbent is conceivable.

  Since there is no mechanical mechanism and it can be constructed around the electronic circuit of the humidity sensor, it is possible to reduce the size and expand the range of use, such as collecting sweat data in everyday life while attached to the body. In addition, it can be manufactured at a lower cost than conventional devices and has a low failure rate because there are no moving parts.

FIG. 1 shows the configuration of the measuring apparatus. FIG. 2 shows changes in humidity obtained by applying the above device to the skin surface of the palm. FIG. 3 shows an example of a method for determining the amount of moisture transpiration from the value of the humidity sensor.

  In order to reduce the size to a size that can be worn in clothes for skin perspiration measurement, and to a size that does not obstruct the function of the measurement target in general industrial measurement, avoid the measurement method using a constant air flow, humidity Realized mainly in sensors.

  Assuming that the measured value is saturated when the amount of moisture transpiration is large, it is possible to measure even a large amount of moisture transpiration by adsorbing the excess water after calibration with a hygroscopic (drying) agent (such as silica gel).

  FIG. 1 shows the simplest embodiment. A moisture absorbing (drying) agent 4, a mesh partition plate 3 for retaining the moisture absorbing agent, and a humidity sensor 6 in an outer box 1 having a plurality of holes 2 for catching moisture transpiration from a measurement object. Are attached to the electric circuit board 5.

  In order to obtain an absolute value of the amount of moisture transpiration, the sensor 6 is a type that can measure absolute humidity, or a type that can calculate absolute humidity by a method such as temperature correction after measuring relative humidity. The electric circuit board 5 is subjected to simple waterproofing.

  When only the sensor and the signal processing circuit are mounted on the electric circuit board 5 of FIG. 1, the lead wire for leading the output signal is drawn out of the outer box 1 and recorded. However, when the microcomputer, the memory, and the battery are mounted on the electric circuit board 5, only the configuration of FIG. This configuration can be realized with a size of 2 × 3 × 2 cm or less.

  FIG. 2 shows an example of palm skin perspiration data obtained using the apparatus of FIG. 1 equipped with a microcomputer, a memory, and a battery. “Sweating amount” in the figure is a simultaneous measurement value by a conventional sweat meter based on the same principle as that of Patent Document 2. Both variations correlate very well, indicating that the apparatus of FIG. 1 is sufficiently practical.

  Normally, the humidity sensor outputs relative humidity. Therefore, it is better to convert the value into absolute humidity by the temperature correction, and further to the conventional moisture transpiration amount, that is, the moisture amount per unit time and per unit area (for example, [g / cm 2 / hr]).

  As a conventional method for obtaining the amount of moisture transpiration using the apparatus of FIG. 1, it is conceivable that one is measured simultaneously with the conventional apparatus as in FIG. 2, and the correlation between the two is measured in advance.

  As another method, there is a method in which the humidity sensor reflects a part of the true value because this device adsorbs moisture to the desiccant, and a theoretical method is built based on this. . As shown in FIG. 3, it is assumed that the moisture amount x obtained by multiplying the humidity sensor output by the effective volume V of the sensor space is obtained as time-lapse data. Here, by adding the bias Δx that could not be detected by the humidity sensor to x, the true water evaporation amount y can be obtained. In order to obtain Δx, first, before and after the measurement time T, the mass of the hygroscopic agent is measured, and the increase W is obtained. Also, the humidity sensor output fluctuation is integrated to obtain an average value S. From this, Δx = W / TS can be obtained.

  In living body measurements, conventional measurements such as long-time outdoor work, physiological examinations during driving of cars and trains and operation of equipment, development of clothes and equipment during exercise with heavy sweating, physiological research during bathing, etc. It can be expected to be used in the field of unconstrained measurement in difficult situations. Therefore, it is possible to provide basic data for all product developments such as health industry, cosmetics, exercise equipment, clothes, bedding, and living environment.

  In medical and dental treatment, it is useful as a patient monitor during surgery and intensive care.

  On the other hand, in the industrial field, the application field is expanded by becoming a small and long-term recorder such as a long-term recording of film moisture permeability and a long-term monitoring of moisture evaporation through a building (wall).

DESCRIPTION OF SYMBOLS 1 Outer box 2 Water vapor | steam inflow hole 3 Reticulated partition plate 4 Hygroscopic agent (silica gel etc.)
5 Electric circuit board 6 Temperature / humidity sensor

Claims (1)

  A humidity sensor, a temperature sensor, and a hygroscopic (drying) agent are placed in a case with one or more holes for introducing water vapor, and an electronic circuit for processing these signals is placed inside or outside the case for processing. A device that saves data and calculates the sweating of the body and the amount of water transpiration on the surface of the object over time, and records the results.

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