JP5154051B2 - Apparatus for measuring environment and measuring method for wound dressing in skin - Google Patents

Description

  The present invention relates to an apparatus for simulating the environment of a minute space between human skin and a wound dressing and a method for measuring the same. In particular, the present invention relates to an apparatus and a measurement method that reproduce and measure temperature and humidity characteristics in a minute space between human skin and a wound dressing material in a wound part or a pressure ulcer part at the time of wound covering.

  Wound treatment methods for skin wounds can be broadly divided into so-called dry dressing that keeps the wound part dry and heals crusts to heal, and creates a moderately moist environment, so that the wound heals quickly. Thus, there is known a wet dressing that has less dry necrosis on the surface of the wound part and also has a wound protective effect.

  In the latter case, it is very important in wound healing to obtain information on a moderate moist environment, that is, the environment of a minute space between a human wound skin and a wound dressing material, particularly temperature and humidity characteristics. However, it is very difficult to measure the temperature and humidity characteristics of human wounds or pressure ulcers, and it is extremely difficult to measure over long periods of time, so it is still difficult to measure the minute space between wound skin and wound dressing in humans. Information on the environment, especially temperature and humidity characteristics, etc. has not been obtained, and there are no reports on them.

On the other hand, there has been no report of making a simulated measurement device that can reproduce conditions close to the microscopic space between the wound skin and the wound dressing material in humans and using it to measure the temperature and humidity characteristics.
For this reason, in examining the wound healing environment, it is possible to measure under conditions close to the minute space between the wound skin and the wound dressing material in humans, without requiring a large facility and measuring samples. It is desired to develop a simulation measuring apparatus and a measuring method that can be easily performed. In developing a wound dressing, a simulation measuring device and a measuring method thereof that can be easily used for evaluating the wound dressing are desired.

  Accordingly, an object of the present invention is to provide an apparatus and method for simulating and measuring the temperature and humidity characteristics in a minute space between human skin and a wound dressing material such as a wound part and a pressure ulcer part at the time of wound covering. It is.

The environment simulation measurement apparatus of the present invention measures and reproduces the temperature and humidity characteristics in a minute space between a wound skin and a wound dressing material in a human .
This device is installed in a constant temperature and humidity chamber that simulates the usage environment of the wound dressing, and heats a container containing moisture to a temperature that mimics the body temperature. “Warming device”, “ Water vapor diffusion adjusting member arranged to cover the opening of the container and adjusting the amount of water vapor permeation” and “Water vapor diffusion adjusting member arranged on the outer surface side of the water vapor diffusion adjusting member , having water vapor permeability, wound “Sample holder holding body imitating skin ” and “Sample of wound dressing held on sample holder so as to form closed space imitating micro space between said sample holder” and “above A sensor for measuring at least one of temperature and humidity in a closed space.

Moreover, the environment simulation measurement method of the present invention is a method for simulating and measuring the temperature and humidity characteristics in a minute space between a wound skin and a wound dressing material in humans , and includes the following steps.
(1) A heating device is placed in a constant temperature and humidity chamber that simulates the usage environment of the wound dressing.
(2) A container containing moisture is heated to a temperature imitating human body temperature by a heating device in a constant temperature and humidity chamber.
(3) arranged on the outer surface side of a water vapor diffusion adjusting member for adjusting the amount of water vapor permeation disposed so as to cover the opening of the container, having a water vapor permeability, on the sample holder imitating wound skin , A sample of the wound dressing is placed so as to form a closed space imitating the minute space between the sample holder and the sample holder.
(4) A sensor is arranged in the closed space between the sample holder and the sample, and at least one of temperature and humidity in the closed space is measured.

  According to the present invention, the environment in the space between the human skin and the wound dressing applied thereon can be simulated and the local environment (temperature and humidity) can be evaluated. Therefore, it is possible to measure for a long time which is difficult when a human body is used as a specimen, and the temperature and humidity characteristics between the skin and the wound dressing can be clarified. This can facilitate the development of better wound dressings suitable for use.

  In addition, when a plurality of containers are arranged on a heating device in a constant temperature and humidity chamber, simultaneous measurement of a plurality of samples can be easily performed.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a temperature and humidity characteristic simulation measurement apparatus according to an embodiment of the present invention. This device measures the temperature and humidity characteristics of the micro space between the wound dressing (or patch) and the skin in a simulated manner.

<< Device configuration >>
This apparatus includes a constant temperature and humidity chamber 14 that adjusts the external environment, a heat exchanger 12 that is surrounded by a heat insulating material 13 and a constant temperature water tank 10 that supplies warm water to the heat exchanger 12. Prepare. Hot water circulates in the constant temperature water tank 10 and the heat exchanger 12 using the pump 11. The container 1 is detachably mounted on the heat exchanger 12.

  The heat exchanger 12 is preferably an insulated water tank, and the temperature of the heat exchanger 12 can be adjusted by circulating the hot water in the constant temperature water tank 10 installed outside the constant temperature and humidity tank 14 with the pump 11. A preferable temperature of the heat exchanger 12 is 30 ° C. to 40 ° C., and a more preferable temperature is 37 ° C. ± 2 ° C. This mimics the temperature range of general body temperature.

  In the illustrated example, a heat exchanger 12 (and a constant temperature water tank 10 and a pump 11 for circulating hot water therein) are employed as a heating device that warms the container 1 to a temperature simulating human body temperature. However, other appropriate heating devices such as an electric heater can be employed.

  As will be described later, the sample holder 3 (in some cases, a combination of this and the water vapor diffusion adjusting member 4) imitates human skin, and the sample 5 (wound dressing material) is placed thereon. The minute space 6 generated between them is regarded as “the minute space between the human skin and the wound dressing”. And the temperature and humidity of this micro space 6 are measured with a sensor.

  The container 1 placed on the heat exchanger 12 is preferably made of a material having good thermal conductivity, for example, a metal such as stainless steel, aluminum, brass, iron, or copper. A water retention member 2 is installed inside the container 1, the upper opening of the container 1 is covered with the water vapor diffusion adjusting member 4, and the sample holder 3 is disposed on the upper surface thereof.

  The water in the water retention member 2 is heated to a temperature close to the body temperature by the heat exchanger 12 and evaporated to pass through the water vapor diffusion adjusting member 4 and the sample holder 3. That is, it mimics sweating from human skin. Therefore, the vapor diffusion adjusting member 4 and the sample holder 3 need to be made of a material that allows water vapor to pass therethrough.

Non-woven fabric, woven fabric, cellophane, polystyrene film (PS), various membrane filters for filtration, etc. can be used as the water vapor diffusion adjusting member 4, but depending on the simulated conditions of the wound or pressure ulcer covered with the wound dressing The water vapor diffusion adjusting member 4 can be omitted. Various combinations of the water retention member 2 and the water vapor diffusion adjusting member 4 can set various simulated conditions of the environment in the wound or pressure ulcer covered with the wound dressing.
That is, in the case of wet skin where a large amount of exudate is present in the wound or pressure ulcer, the water-retaining member 2 should be made of a material with good water and transpiration properties, and should be sufficiently hydrated. In the container 1, the water vapor diffusion adjusting member 4 may be measured without using it.
On the other hand, in the case of skin having almost no exudate in the wound or pressure ulcer, water is contained in the water retention member 2 having poor water content and transpiration, and the water vapor diffusion control member 4 is made of a material that suppresses water vapor diffusion to some extent. It may be measured using. Furthermore, it is possible to set simulation conditions even in the case of normal skin.

The sample holder 3 is for holding the sample 5 so as to cover the opening of the container 1, and is preferably made of a material having an appropriate strength for that purpose and capable of easily removing the sample after the test. For example, a thin plate made of Teflon (Teflon is a registered trademark), a thin plate coated with silicon, a thin plate coated with fluororesin, or the like can be used. In particular, a thin plate made of Teflon (Teflon is a registered trademark) is preferable.
Since the sample holder 3 is also required to have water vapor permeability, it is manufactured in a mesh shape or provided with an appropriate opening.

The water retention member 2 may be a water retention member, that is, a sponge such as cellulose, polyvinyl alcohol (PVA), urethane, melamine resin, or sponge, and the water content and transpiration amount differ depending on the material. A material that meets the target measurement conditions can be selected. The water-retaining member 2 is sufficiently hydrated by immersing it in water before starting the test, and then installed inside the container 1.
In addition, since it is sufficient for the container 1 to contain moisture therein, it is also possible to put water directly into the container without using the water retention member 2.

  As sample 5, various wound dressings or patches such as poultices, tapes and plasters are used.

  The temperature and humidity in the minute space 6 formed between the sample holder 3 and the sample 5 are measured by a temperature and humidity sensor. Although an individual temperature sensor and humidity sensor may be used, it is preferable to use a temperature / humidity sensor capable of measuring both. For the convenience of measurement, a small and thin sensor is desirable.

It is preferable that the constant temperature and humidity chamber 14 for adjusting the external environment can be adjusted in a range of 20 ° C. to 40 ° C. and a humidity of 25% to 99% RH, and the air volume can be changed. This is to mimic the environment in which the wound dressing is used, and to reproduce the normal indoor environment and the environment in the futon (bedding).
As preferable conditions of the external environment, the temperature is 20 ° C. to 40 ° C., the humidity is 30% RH to 80% RH, more preferably the temperature is 25 ° C. to 35 ° C., and the humidity is 40% RH to 60% RH. is there.

≪Measurement method≫
The measuring method according to the present invention is as follows.
A heat exchanger 12 is installed inside the constant temperature and humidity chamber 14, and hot water is circulated by the pump 11 from the constant temperature water tank 10 installed outside, so that the heat exchanger 12 is preliminarily adjusted to a temperature corresponding to the local body temperature. Warm up. At this time, the container 1 installed on the heat exchanger 12 is also preheated simultaneously (the sample 5 is not yet placed on the sample holder 3).

After preliminary heating, the weights of “Sample 5” and “Container 1 without Sample 5” are measured (Measurement 1). After installing the thin temperature / humidity sensor 7 on the sample holder 3 of the container 1 and placing the sample 5 thereon, the periphery of the container 1 is sealed with sealing tape 9 so that water vapor does not leak, Install on heat exchanger 12.
The temperature / humidity sensor 7 is installed in a minute space 6 formed between the sample holder 3 and the sample 5, and is connected to a measuring device (not shown) disposed outside the thermostatic chamber 14 via the lead wire 8. Connected and outputs temperature and humidity measurements over time.
If a plurality of containers 1 are installed on the heat exchanger 12, a plurality of types of samples 5 can be measured simultaneously.

  While measuring the temperature and humidity in the minute space 6 with the temperature and humidity sensor 7, the total weight of the container 1 (including the sample 5 on it) is also measured with time (measurement). 2). This measurement can be performed, for example, by placing a weighing device (not shown) in the constant temperature and humidity chamber 14.

  By subtracting the total weight of the container 1 measured in “Measurement 2” from the total weight of “Sample 5” measured in the above “Measurement 1” and “Container 1 without the sample 5”, the inside of the container 1 The amount of water transpiration can also be measured over time (measurement 3).

  After the test is completed, the weight of the sample 5 alone is measured, and the water absorption amount of the sample 5 itself can be calculated by subtracting the weight of the sample 5 obtained in the above “Measurement 1”. By subtracting the calculated water absorption amount from the final transpiration amount obtained in the above “Measurement 3”, the amount of steam that has passed through the sample 5 can be obtained. Furthermore, by dividing this by the test time, “moisture permeability per hour of sample 5” can be calculated.

Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In each Example, the following wound dressing material marketed for treating pressure ulcers was used as Sample 5.
Commercial product A (component: hydrocolloid material)
Commercial product B (component: polyurethane film material)
Commercial product C (component: hydrogel material)
Commercial product D (component: polyurethane film material)

Using the wound dressings of commercial products A and B as sample 5, humidity, which is one of the external environmental factors, was examined.
The water retention member 2 and the water vapor diffusion adjusting member 4 were previously installed in the heat exchanger 12 installed in the constant temperature and humidity chamber 14 (Tokyo Science Instruments: EYELA constant temperature and humidity chamber KCL-2000W) with adjustable external environment. Container 1 was placed and preheated.
After preliminary warming, a sample 5 (commercial wound dressing) and a thermohygrometer 7 (manufactured by Shinei: Digifull thermohygrometer TRH-CA) were installed in the container 1. The external environment was set to 35 ° C. assuming the temperature in the bedding, and the humidity was set to 40% RH, 50% RH, and 60% RH, and the humidity and temperature of the microspace 6 were examined over time. The measurement results are shown in Tables 1 and 2.
After 60 minutes from the start of measurement, both the commercial products A and B had almost no difference in the temperature and humidity in the microspace 6 under the condition that there was exudate in the pressure ulcer (wet state). On the other hand, under conditions where there was no exudate in the pressure ulcer (dry state), there was almost no difference in the temperature in the micro space 6, but the humidity in the micro space increased with increasing humidity in the external environment.

In the same manner as in Example 1, the wound dressings of the commercial products A and B were used as the sample 5, and various water retention members 2 and water vapor diffusion adjusting members 4 were examined. The external environment was a temperature of 35 ° C. and a humidity of 40% RH. The results are shown in Table 3.
It was found that the humidity in the minute space 6 can be adjusted by combining the various water retention members 2 and the water vapor diffusion adjusting member 4, and the presence or absence of exudate in the pressure ulcer can be simulated.

In the same manner as in Example 1, using commercially available wound dressings A, B, C, and D as sample 5, changes in humidity and temperature in micro space 6 in a short time were measured over time. The external environment was a temperature of 35 ° C. and a humidity of 40% RH. The results are shown in Table 4.
Under conditions where there is exudate in the pressure ulcer part, the temperature and humidity in the microspace 6 were almost the same for the four types of commercial products, but under conditions where there was almost no exudate, the commercial products B and D tended to have a slightly lower humidity in the minute space 6. This was thought to be due to the difference in the composition of the commercial products.

In the same manner as in Example 1, using commercially available wound dressings A, B, C, and D as sample 5, changes in humidity and temperature in the minute space 6 over time were measured over time. The external environment was a temperature of 35 ° C. and a humidity of 40% RH. The results are shown in Table 5.
Under the conditions of each pressure ulcer part, the humidity in the microspace 6 in all commercially available products was kept at 95% RH to 99% RH until 24 hours after the start of measurement, and the temperature was constant at around 35 ° C. .

As can be seen from the results of the above examples, it is important for wound healing by using this environment simulation measuring device that reproduces and measures the environment of the minute space between the human skin and the wound dressing. It has become possible to obtain information on a moderate moist environment, which is a factor, that is, the environment of a minute space between a wound skin and a wound dressing material in humans, particularly temperature and humidity characteristics over a long period of time.
This environmental simulation measuring device is very useful for the development of new wound dressings in addition to the evaluation of existing wound dressings.

Schematic explaining the apparatus which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Container 2 Water retention member 3 Sample holding body 4 Water vapor | steam diffusion adjustment member 5 Sample (wound dressing material)
6 Microspace 7 Temperature / humidity sensor 8 Lead wire 9 Sealing tape 10 Constant temperature water tank 11 Pump 12 Heat exchanger 13 Heat insulating material 14 Constant temperature and humidity chamber

Claims (5)

A device that reproduces and measures temperature and humidity characteristics in a micro space between a wound skin and a wound dressing in humans ,
A constant temperature and humidity chamber (14) that simulates the usage environment of the wound dressing;
A heating device (12) that is installed in a constant temperature and humidity chamber (14) and that heats the container (1) containing moisture to a temperature simulating body temperature;
A water vapor diffusion adjusting member (4) disposed so as to cover the opening of the container (1) and adjusting the amount of water vapor permeated;
A sample holder (3) disposed on the outer surface side of the water vapor diffusion adjusting member (4), having water vapor permeability and imitating wound skin ;
A wound dressing sample (5) held on the sample holder (3) so as to form a closed space (6) imitating the minute space with the sample holder (3);
An environmental simulation measurement device comprising: a sensor (7) for measuring at least one of temperature and humidity in the closed space (6).
The environmental simulation measuring device according to claim 1, wherein the container (1) contains a water retaining member (2) containing water.
The environment simulation measuring device according to claim 1, wherein a plurality of said containers (1) are installed.
The environment simulation measuring apparatus according to claim 1, wherein the sensor is a temperature / humidity sensor capable of measuring temperature and humidity.
A method for reproducing the temperature and humidity characteristics in a minute space between a wound skin and a wound dressing material in humans ,
In the constant temperature and humidity chamber (14) that simulates the use environment of the wound dressing, the heating device (12) is arranged,
The container (1) containing moisture is heated to a temperature imitating human body temperature by a heating device (12) in a constant temperature and humidity chamber (14),
A sample holder that is disposed on the outer surface side of the water vapor diffusion adjusting member (4) that adjusts the amount of water vapor permeated to cover the opening of the container (1), has water vapor permeability, and simulates wound skin ( 3) The sample (5) of the wound dressing is placed on the sample holder so as to form a closed space (6) that imitates the micro space,
An environmental simulation measurement method, comprising: arranging a sensor (7) in the closed space (6), and measuring at least one of temperature and humidity in the closed space (6).

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