WO2009125539A1

WO2009125539A1 - Heat and moisture exchanger, heat and moisture exchanging device, and mask

Info

Publication number: WO2009125539A1
Application number: PCT/JP2009/001047
Authority: WO
Inventors: Akito Ohmura; Kunihisa Eguchi; Katsuyoshi Goto
Original assignee: Furrex Co., Ltd.
Priority date: 2008-04-09
Filing date: 2009-03-09
Publication date: 2009-10-15
Also published as: JP2011516102A; JP5444247B2

Abstract

A respiratory heat and moisture exchanger for adjusting temperature and moisture of gas to be inhaled and having a heat storage carrier material and a moisture absorption and release material, wherein a gradient along a direction of flow of respiration gas that passes through the respiratory heat and moisture exchanger is provided to at least one property selected from the properties of density, surface area, perforation rate, and number of cells of the heat storage carrier material that constitutes the respiratory heat and moisture exchanger, or additive density and moisture absorption and release capability of the moisture absorption and release material added to the respiratory heat and moisture exchanger.

Description

HEAT AND MOISTURE EXCHANGER, HEAT AND MOISTURE EXCHANGING DEVICE, AND MASK

The present invention relates to a respiratory heat and moisture exchanger, heat and moisture exchanging device, and mask, and more particularly, to a respiratory heat and moisture exchanger, heat and moisture exchanging device, and mask for appropriately adjusting the temperature and moisture of a gas such as air for a patient to inhale.

Respiratory heat and moisture exchangers include, in the medical field for example, the members installed in heat and moisture exchanging devices that are used when subjecting patients to anesthesia or to artificial respiration, as well as the members mounted in typical and widely used surgical masks to provide a moisturizing function.

Heat and moisture exchanging devices, also called artificial noses, are heating and moisturizing devices used when subjecting patients to anesthesia or artificial respiration to adjust the temperature and moisture of air or other such gases breathed by the patient in order to prevent the introduction of dry air or other gas into the patient's air passage and lungs.

By providing a heat and moisture exchanging device along the flow path of respiratory air, air for breathing that is closer to the temperature and humidity conditions of the patient's own exhaled breath can be introduced into the patient while the patient is under anesthesia using an anesthesia device or is subjected to artificial respiration using a respirator, thereby reducing the physical burden on the patient.

As is known, a heat and moisture exchanging device does not adjust the temperature and moisture of the air to be inhaled by actively adding heat and moisture as an ordinary humidifier does. Rather, a heat and moisture exchanging device is a passive device that adds heat and moisture by storing the heat and moisture in the patient's exhaled breath in its own internal element and releasing that stored heat and moisture to the air that the patient inhales. A heat and moisture exchanging device provided with an auxiliary moisture and heat storage unit is proposed in Patent Citation 1.

In Patent Citation 2, a mask that not only provides an improved humidifying function using a water-absorbing and water-retaining material but which also actively heats using a heat generator, thus adding heat and moisture, is proposed as a humidifying mask. In addition, a mask having a woven copper cloth for storing heat in an exhaled breath and adding the stored heat to an inhaled breath to warm the same in Patent Citations 3 and 4.
Japanese Patent Application Laid-open Publication No. 2006-136461 Japanese Patent Application Laid-open Publication No. 2000-225205 United States Patent No. 5706802 United States Patent No. 6196221

These heat and moisture exchanging devices does not such functions as raising the temperature of the air to be inhaled and moisture absorption and release capabilities. In the existing heat and moisture exchanging devices, addition of a heater is required to achieve active heating function. Furthermore, in the above-mentioned masks, although heating of a gas to be inhaled is enabled, lack of moisture absorption and release capabilities may result in condense of water inside the mask.

Accordingly, through International Patent Application Publication No. WO2008/044792A1 the applicant has proposed a heat and moisture exchanging device in which the density of material forming a carrier installed in the heat and moisture exchanging device is greater on the patient side of the heat and moisture exchanging device than on the circuit side of the heat and moisture exchanging device as one means of improving the heat regeneration rate.

However, with this heat and moisture exchanging device, the heat storage part of the carrier is located downstream when the patient inhales, and therefore is susceptible to the effects of heat loss due to radiation and the like. Moreover, because the heat of adsorption or the heat of absorption stolen from the exhaled air when moisture in the exhaled air is adsorbed or absorbed by the carrier is present, storage of heat from the exhaled air to the carrier is inadequate. Consequently, in addition to the temperature of the air to be inhaled falling below a required temperature with the loss of heat from the exhaled air, the amount of moisture added to the air that the patient inhales also decreases.

Therefore, when regenerating heat from exhaled air into the air to be inhaled by a patient that is sent from an artificial respirator or an anesthetic device to the patient through a heat and moisture exchanging device, further increasing the heat regeneration rate of the respiratory heat and moisture regenerator disposed within the heat and moisture exchanging device is a problem to be solved.

In addition, with respect to the heat and moisture exchanging device described above, it is recognized that, as the capacity to add heat improves, there is room for improvement also in the capacity to add moisture. Further, with the structure proposed above, it has been confirmed that there is an unevenness in the amount of moisture stored in the moisture absorption and release material added to the respiratory heat and moisture exchanger inside the heat and moisture exchanging device.

More specifically, compared to on the circuit side of the heat and moisture exchanging device, where moisture is released, on the patient side the amount of moisture that is stored remains particularly large, thereby possibly causing clogging of the heat and moisture exchanging device due to localized increases in moisture inside the respiratory heat and moisture exchanger.

When the patient inhales, as the air or gas travels from the circuit side to the patient side in the heat and moisture exchanging device, moisture is released into the air to be inhaled, which contains little moisture and is dry (having a temperature of 23 degrees C and a humidity of 5% or less). As a result, the relative humidity on the patient side of the heat and moisture exchanging device increases while the relative humidity on the circuit side decreases, so that, in the same moisture absorption and release material, there is likely to appear an unevenness in distribution of the amount of moisture that is released.

For example, in a case in which calcium chloride (CaCl₂) is used as the moisture absorption and release material, in a case in which the relative humidity is 20% and in a case in which the relative humidity is 80%, in the case in which the relative humidity is 80% the rate of moisture release decreases, and therefore, on the patient side, where the moisture of the air to be inhaled has increased, the rate of moisture release decreases and the amount of moisture stored within the respiratory heat and moisture exchanger becomes excessive.

Accordingly, in the respiratory heat and moisture exchanger inside the heat and moisture exchanging device, limiting the imbalance in the amount of moisture accumulated on the patient side and on the circuit side, suppressing localized increases in moisture, and preventing clogging are problems to be solved.

In order to solve these and other problems, one aspect of the present invention provides a respiratory heat and moisture exchanger for adjusting temperature and moisture of gas to be inhaled and having a heat storage carrier material and a moisture absorption and release material, wherein a value for at least one property selected from the properties of density, surface area, perforation rate, and number of cells of the heat storage carrier material that constitutes the respiratory heat and moisture exchanger is given a gradient along a direction of flow of respiration gas passing through the respiratory heat and moisture exchanger, such that the density is set to increase and the surface area, the perforation rate, or the number of cells is set to decrease on a downstream side of a flow of gas to be inhaled.

Another aspect of the present invention provides a respiratory heat and moisture regenerator for adjusting temperature and moisture of gas to be inhaled and having a heat storage carrier material and a moisture absorption and release material, wherein a value for at least one of a property selected from the properties of additive density and moisture absorption and release capability of the moisture absorption and release material added to the heat storage carrier material that constitutes the respiratory heat and moisture exchanger is given a gradient along a direction of flow of respiration gas passing through the respiratory heat and moisture exchanger, such that the additive density or the moisture absorption capability is set to increase, or the moisture release capability is set to decrease, on an upstream side of a flow of gas to be inhaled.

Further aspect of the present invention is a heat and moisture exchanging device in which any of the above respiratory heat and moisture exchanger is installed.

Yet further aspect of the present invention is a mask with a respiratory heat and moisture exchanging function, comprising a mask body provided at the mouth of a user, and a pair of ear hooks extending from two opposed outer lateral sides of the mask body, wherein the mask body having a respiratory heat and moisture exchanger including a heat storage carrier material carrying a moisture absorption and release material so that gas inhaled and exhaled by the user flows through the respiratory heat and moisture exchanger.

It is to be noted that although a combination of sodium chloride and calcium chloride, for example, can be used for the moisture absorption and release material, the present invention is not limited thereto. Provided the material is harmless and can be made to come into contact with respiratory gases, other and different combinations of compounds may be adopted for the moisture absorption and release material. Alternatively, a single compound such as calcium chloride may be adopted for the moisture absorption and release material.

With the above-described structure, the heat storage unit, in which the carrier material of the respiratory heat and moisture exchanger is densest, is located upstream when the patient inhales, thereby enabling heat loss due to radiation and the like to be reduced and improving the efficiency with which the heat of the exhaled gas is regenerated.

Further, heat of adsorption or heat of absorption generated when moisture is adsorbed or absorbed can be stored in the dense heat storage unit which is located downstream when the patient exhales, thus improving the efficiency with which the heat of the exhaled gas is regenerated.

Moreover, on the upstream end of the flow of gas to be inhaled of the respiratory heat and moisture exchanger, the density or the moisture absorption capacity is enhanced, or the moisture release capacity is reduced, thereby enabling clogging of the heat and moisture exchanger due to moisture accumulation on the patient side to be prevented.

FIG. 1 is a schematic structural diagram of a measuring device used to confirm the effects of a respiratory heat and moisture exchanger according to one embodiment of the present invention. FIG. 2 is a comparative example (Sample 1) of a heat and moisture exchanger. FIG. 3 is a schematic cross-sectional view of one example (Sample 2) of a heat and moisture exchanger according to Example 1 of the present invention. FIG. 4 is a schematic cross-sectional view of another example (Graded) of a heat and moisture exchanger according to Example 1 of the present invention. FIG. 5 is a schematic cross-sectional view of another and further example (Layered) of a heat and moisture exchanger according to Example 1 of the present invention. FIG. 6 is a diagram showing inhalation air temperature characteristics of a heat and moisture exchanger according to Example 1 of the present invention (Sample 2) and the comparative example (Sample 1). FIG. 7 is a schematic cross-sectional view of a heat and moisture exchanger according to the comparative example (Sample A) of the present invention. FIG. 8 is a schematic cross-sectional view of one example of a heat and moisture exchanger according to a second embodiment (Sample B) of the present invention. FIG. 9 is a schematic cross-sectional view of another example (Variation 1) of a heat and moisture exchanger according to Example 2 of the present invention. FIG. 10 is a schematic cross-sectional view of another and further example (Variation 2) of a heat and moisture exchanger according to Example 2 of the present invention. FIG. 11 is a diagram showing residual water amounts of a heat moisture exchanger according to Example 2 (Sample B) of the present invention and a comparative example (Sample A). FIG. 12 is a diagram showing water loss in a heat and moisture exchanger according to Example 2 (Sample B) of the present invention and the comparative example (Sample A). FIG. 13A is a schematic view of a mask of one example according to Example 3 of the present invention. FIG. 13B is a schematic cross-sectional view of a mask body of one example according to Example 3 of the present invention.

Embodiments of Invention

A description is given below of aspects of the present invention. As an application of the respiratory heat and moisture exchanger, the description proceeds using as an example a heat and moisture exchanging device and a mask.

Heat and moisture exchanging device
Measuring device
The effect that the heat and moisture exchanging device provided with the respiratory heat and moisture exchanger according to the present embodiment has been confirmed experimentally by a measuring device configured using a lung simulator. A schematic structural diagram of the measuring device is shown in FIG. 1.

The measuring device simulates a patient's breathing, and is constituted by a lung simulator 1, a heated humidifier 2, a ventilator 3, a compressor 4, 3-

way valves

5A and 5B, fast-

response thermocouples

6A and 6B, temperature and

humidity sensors

7A and 7B, and a respiration circuit 8.

The lung simulator 1 is a device that simulates the breathing movement of a patient. Two sets of lines are led out from the lung simulator 1, line A as an inhalation air line and line B as an exhalation air line. The inhalation line A is connected to a first port of the 3-way valve 5A through the fast-response thermocouple 6A that measures the temperature of the air that is inhaled. The exhalation line B is connected to the fast-response thermocouple 6B through the heated humidifier 2, and is further connected to a second port of the 3-way valve 5A.

To a third port of the 3-way valve 5A is connected a heat and moisture exchanging device (artificial nose) 9, which in turn is connected to the other 3-way valve 5B.

Two sets of lines are also led out from the ventilator 3 connected to the compressor 4, line A as an inhalation air line and line B as an exhalation air line. The inhalation air line A is connected to a first port of the 3-way valve 5B through the temperature and humidity sensor 7A that measures the temperature and humidity of the air that is inhaled. The exhalation air line B is connected to the temperature and humidity sensor 7B and further to a second port of the 3-way valve 5B.

The 3-

way valves

5A and 5B switch between the inhalation air line A and the exhalation air line B in synchronism with the simulated breathing movement of the ventilator 3.

The exhaled air expelled from the lung simulator 1 is heated to 37 degrees C and humidified to 100% humidity by passing through the heated humidifier 2 and the heat and moisture contained therein is expelled to the heat and moisture exchanging device 9, thereby simulating the patient's respiratory function.

Ambient environment conditions were set to a temperature of 23 degrees C plus or minus 1 degree C and a relative humidity of 50% plus or minus 20%.

Example 1

Sample 1 consisted of a heat storage carrier material that constitutes the respiratory heat and moisture exchanger having a density or nominal density that was uniform, and Sample 2 consisted of a heat storage carrier material whose density or nominal density was given a density gradient, such that the density was lesser on the patient side and greater on the circuit side.

Each sample used a polyurethane foam to which calcium chloride was added. A nominal volume formed into a substantially cylindrical shape was within a range of 65 cm³ - 200 cm³, with the added amount of the calcium chloride within a range of 0.3 - 1.5 g.

The shape of Sample 1 is one in which the density of the polyurethane foam is made uniform as shown in FIG. 2. The density is 55 kg/m³. The shape of Sample 2 is one in which the density of the polyurethane foam is given a gradient as shown in FIG. 3. The density ranges, in order from the patient side, from 30 to 55 to 70 kg/m³.

As for the rest of the structure, with respect to the density or the nominal density of the heat storage carrier material, the density gradient, in which the density is greatest on the respiratory circuit and the anesthetic circuit side and least on the patient side, an arrangement may be adopted in which the density is slanted so that the density of each layer is changed in steps as shown in FIG. 4, or in which the density is layered so as to vary the thicknesses of the respective portions of different densities as shown in FIG. 5. Here, the surface area, the perforation rate, or the number of cells of the heat storage carrier material may be set relatively smaller at the patient side of the heat and moisture exchanging device.

When Sample 1 and Sample 2 are compared as shown in FIG. 6, even when the heat capacities of the samples are changed, in a case in which the heat capacity is the same the temperature of the air to be inhaled is higher in Sample 2.

From this, with respect to the density or the nominal density of the heat storage carrier material in the heat and moisture exchanging device, it can be confirmed that the efficiency with which the heat of the exhaled air is regenerated into the air to be inhaled that is sent to the patient from the artificial respirator or the anesthetic device through the heat and moisture exchanging device is improved by giving the density a gradient such that the density is greatest on the circuit side and least on the patient side.

Example 2

Next, two types of samples, Sample A and Sample B, were prepared in order to compare the heating and humidifying characteristics of a heat and moisture exchanging device provided with a respiratory heat and moisture exchanger according to a second embodiment of the present invention.

Sample A
Using a heat storage carrier material made of polyurethane foam formed into a substantially cylindrical shape having a nominal volume of 52.3 cm³, the carrier is divided into four layers, a first layer through a fourth layer, in which the density varies, in order from the patient side, from 30 to 55 to 55 to 70 kg/m³, with each layer having a thickness of 5.5 mm. In other words, the heat storage carrier material of Sample A is given a density gradient such that the density increases from the patient side toward the circuit side. The heat storage carrier material is held inside a container provided with openings at two places through which simulated respiratory air passes, and connected to the measuring device through that container. The same arrangement applies for Sample B as well.

Calcium chloride is added to each of the layers of this heat storage carrier material, in amounts ranging, in order from the patient side, from 0.53 to 0.42 to 0.42 to 0.5 g. A schematic side view of Sample A is shown in FIG. 7.

Sample B
In Sample B, sodium chloride is added to heat storage carrier material having the same density gradient as that of Sample A in amounts ranging, from the patient side, from 0 for the first layer, to 1.04 g for the second layer, to 0.42 g for the third layer, to 0.5 g for the 4th layer. A schematic side view of Sample B is shown in FIG. 8.

An amount of water loss for each sample was measured using the measuring device described above and the measurement results compared.

The amount of residual water remaining inside each of the samples using the heat and moisture exchanging devices according to Samples A and B described above was evaluated through measuring an integrated value of the water amount in the exhaled breath from each sample and the residual water amount remained in each sample, and based on the total amount of the both calculating the water loss amount under simulated breathing conditions of 500 ml of displaced air per breath and 15 breaths per minute for 20 minutes continuously. Results of measurements of the amount of residual water in each layer of polyurethane foam are shown in FIG. 11, with results of a comparison of water loss amount for each sample, shown in FIG. 12.

As for the amount of residual water in each layer of the heat storage carrier material shown in FIG. 11, in Sample A, to which calcium chloride alone was added, localized accumulation of water is particularly acute and the first layer of the patient side. However, in Sample B to which was added sodium chloride in place of calcium chloride, water accumulation is more or less uniform, indicating that localized increases of water have been prevented.

In addition, with respect to the water loss shown in FIG. 12, such water loss is less for Sample B, which employed sodium chloride as an additive, thus confirming that overall moisture release characteristics have been improved as well.

From these facts, it can be confirmed that a heat and moisture exchanging device having a structure in which sodium chloride is used on the patient side and calcium chloride is used on the circuit side can not only prevent the localized accumulation of moisture internally and prevent clogging but can also improve moisture release efficiency.

It is to be noted that, as configurations other than those illustrated in Samples A and B, so long as sodium chloride is provided on the patient side the thickness of the heat storage carrier material provided with calcium chloride and sodium chloride can be varied as shown in FIG. 9 or FIG. 10.

Moreover, as the moisture absorption and release material a combination of sodium chloride and calcium chloride may be used, in which the relative proportions of two chemicals are varied depending on the position of the heat storage carrier material. The relative proportions should be such that there is more sodium chloride on the patient side and more calcium chloride on the circuit side.

Finally, a description is given of the effect of the present embodiment. Comparing the moisture absorption and release characteristics of sodium chloride and calcium chloride, it can be seen that calcium chloride has the greater moisture absorption capability and absorbs more moisture than the sodium chloride does. By contrast, sodium chloride which releases moisture when the relative humidity is 75% or less, has greater moisture release capabilities than calcium chloride does, which continues to absorb moisture even when the relative humidity is 50%.

Utilizing these differences in moisture absorption and release between sodium chloride and calcium chloride, and providing a carrier on the patient side with sodium chloride which has not been used at all as a moisture absorption and release material for conventional heat and moisture exchanging devices, makes it possible to improve the moisture release capabilities at that portion and to prevent clogging due to water accumulation.

Example 3

Masks
Here, a mask according to one embodiment of the present invention will be described with reference to Figs. 13A and 13B. Fig. 13A shows a schematic view of an exemplary mask according to Example 3 of the present invention. Fig. 13B shows a schematic cross-sectional view of the mask body 101 in FIG. 13A.

A mask 100 of the present embodiment includes a mask body 101 to be placed adjacent a wearer's mouth or nasal apertures, the wearer's breath passing the mask body 101 in the direction of its thickness, and a pair of ear hooks 104 extending from each lateral side portion of the mask body 101 to be hung behind the wearer's ears. Each of the ear hooks 104 consists of an elastic cord member made of any suitable material.

The mask body 101 is a generally plane-shaped part, formed by encompassing a plate-like heat and moisture exchanger 102 with an exterior material 103 such as cotton cloth. The heat and moisture exchanger 102 is made up of for example a polyurethane foam as heat storage carrier material and calcium chloride as moisture absorption and releasing material carried in the polyurethane foam. The heat and moisture exchanger 102 is shaped into a rectangular plate having elasticity in general. When the heat and moisture exchanger 102 is formed with such material as can be directly applied to the wearer's mouth into an appropriate shape, it may not be necessary to provide the exterior material 103.

According to the above construction, heat in the exhaled breath is stored in the polyurethane foam as the heat storage carrier material and moisture in the exhaled breath is adsorbed or absorbed by calcium chloride as the moisture absorption and releasing material. Thus, both retaining of the heat in the exhaled breath and condensation inside the mask body 101 are prevented. Moreover, since the heat and the moisture captured from the exhaled breath are released into a gas to be inhaled when inhaling, an effect of warming and moistening of the gas can be achieved.

Further, if, as the moisture and heat exchanger 102, a respiratory heat and moisture exchanger in which a value for at least one property selected from the properties of density, surface area, perforation rate, and number of cells of the heat storage carrier material that constitutes the respiratory heat and moisture exchanger is given a gradient along a direction of flow of respiration air passing through the respiratory heat and moisture exchanger, such that the density is set to increase and the surface area, the perforation rate, or the number of cells is set to decrease, on a downstream side of a flow of air to be inhaled is employed, regeneration efficiency of the heat in the exhaled breath is improved as described above regarding the heat and moisture exchanging device.

Alternatively, if, as the moisture and heat exchanger 102, a respiratory heat and moisture exchanger having a heat storage carrier material and a moisture absorption and release material wherein a value for at least one of a property selected from the properties of additive density and moisture absorption and release capability of the moisture absorption and release material added to the heat storage carrier material that constitutes the respiratory heat and moisture exchanger is given a gradient along a direction of flow of respiration air passing through the respiratory heat and moisture exchanger, such that the additive density or the moisture absorption capability is set to increase, or the moisture release capability is set to decrease, on an upstream side of a flow of air to be inhaled, is employed, clogging due to water accumulation is prevented.

The heat and moisture exchanger 102 may be provided with an intermediate member to be applied to the skin around the wearer's mouth and nose on the surface thereof. According to this construction, the heat and moisture exchanger 102 does not directly touch the wearer's skin and the wearer feels more comfortable when wearing the mask 100. A coarse cotton cloth as gauze and other suitable material may be applied to the intermediate member. In option, the exterior material 103 may be also used as the intermediate member.

It is to be noted that although the present invention is described in terms of embodiments thereof with reference to the accompanying drawings, the present invention is not limited to these embodiments. In addition, the present invention encompasses all variations and equivalents within the scope of the invention.

Claims

A respiratory heat and moisture exchanger for adjusting temperature and moisture of gas to be inhaled and having a heat storage carrier material and a moisture absorption and release material,
wherein a value for at least one property selected from the properties of density, surface area, perforation rate, and number of cells of the heat storage carrier material that constitutes the respiratory heat and moisture exchanger is given a gradient along a direction of flow of respiration gas passing through the respiratory heat and moisture exchanger, such that the density is set to increase and the surface area, the perforation rate, or the number of cells is set to decrease, on a downstream side of a flow of gas to be inhaled.
A respiratory heat and moisture exchanger for adjusting temperature and moisture of gas to be inhaled and having a heat storage carrier material and a moisture absorption and release material,
wherein a value for at least one of a property selected from the properties of additive density and moisture absorption and release capability of the moisture absorption and release material added to the heat storage carrier material that constitutes the respiratory heat and moisture exchanger is given a gradient along a direction of flow of respiration gas passing through the respiratory heat and moisture exchanger, such that the additive density or the moisture absorption capability is set to increase, or the moisture release capability is set to decrease, on an upstream side of a flow of gas to be inhaled.
The heat and moisture exchanger according to claim 2, wherein the moisture absorption and release material includes sodium chloride.
A heat and moisture exchanging device provided with the heat and moisture exchanger according to anyone of claims 1 to 3 inside housing that has a first connecting portion to which is connected a tube communicating with a patient's air passage and a second connecting portion coupled to a source for supplying gas to be inhaled by the patient and a line for expelling gas exhaled by the patient.
A mask with a respiratory heat and moisture exchanging function, comprising:
a mask body provided at the mouth of a user; and
a pair of ear hooks extending from two opposed outer lateral sides of the mask body,
wherein the mask body having a respiratory heat and moisture exchanger including a heat storage carrier material carrying a moisture absorption and release material so that gas inhaled and exhaled by the user flows through the respiratory heat and moisture exchanger.
A mask with a respiratory heat and moisture exchanging function, comprising:
a mask body provided at the mouth of a user; and
a pair of ear hooks extending from two opposed outer lateral sides of the mask body,
wherein the respiratory heat and moisture exchanger of anyone of claims 1 to 3 is disposed within the mask body so that gas inhaled and exhaled by the user flows along the gradient provided to the value for the properties.
The heat and moisture exchanging device according to claim 4, wherein the heat storage carrier material includes polyurethane having a density within a range of 1 - 150 kg/m³.
The heat and moisture exchanging device according to claim 4, wherein the moisture absorption and release material includes calcium chloride and sodium chloride, and sodium chloride is added to the respiratory heat and moisture exchanging device on the first connecting portion side thereof and calcium chloride is added on the second connecting portion side thereof.
The mask according to claim 5 or 6, wherein the heat storage carrier material includes a polyurethane foam.
The mask according to claim 5 or 6, wherein the moisture absorption and release material includes calcium chloride or sodium chloride.
The mask according to claim 5 or 6, wherein a contact-preventing member is provided on a user side of the mask body so that the respiratory heat and moisture exchanger and the skin of the user do not come into contact with each other.