JP2024111279A - Humidifier, breathing aid device - Google Patents

Abstract

To provide a humidifier which can be reduced in size and weight and can quickly and sufficiently humidify without heating whole water to be stored, and a respiration auxiliary device.SOLUTION: A humidifier for humidifying an air supply gas to be supplied to a user comprises: a heat generation part for heating liquid used for humidifying the air supply gas for vaporizing the liquid; a liquid supply part for supplying the liquid to the heat generation part; a power source for supplying energy to the heat generation part; a supplied power measuring part for measuring supplied power supplied from the power source to the heat generation part; a heat generation control part for controlling the supplied power by referring to a temperature in the humidifier or a temperature in a respiration circuit connected to the humidifier; a target supplied power calculation part for calculating target supplied power as a target, on the basis of a target heating and humidifying state about the air supply gas; and a liquid supply control part for controlling a liquid supply amount on the basis of a difference value between the measured supplied power and the target supplied power.SELECTED DRAWING: Figure 1

Description

The present invention relates to a humidifier that humidifies the gas supplied to a user, and a respiratory assistance device equipped with a humidifier.

Automatic ventilation devices designed to connect to the user's airway and regulate or assist ventilation are widely used in medical settings, including respiratory support devices used in CPAP therapy (Continuous Positive Airway Pressure), a treatment for sleep apnea syndrome.

Continuing to deliver dry gas to the airway can cause discomfort to the user and, in some cases, can even lead to damage to the airway. For this reason, respiratory support devices are connected to humidifiers that add moisture to the delivered gas.

Conventionally, most humidifiers used in respiratory assistance devices have used a heating element (heater plate) to heat and evaporate all the water contained in the water tank (see, for example, Patent Document 1).

Figure 9 (A) is a conceptual diagram of a conventional respiratory assistance device 101. The respiratory assistance device 101 is equipped with a humidifier 105 that employs a heating and evaporation method. The humidifier 105 takes in the supply gas sent from the ventilator 110 through the supply gas inlet 115, heats and humidifies it, and sends it out from the supply gas outlet 120 to the inhalation side breathing circuit 127. The supply gas passes through the coiled tube 130 and is sent from the interface 135 to the user U. Exhaled air is released to the outside world through the exhalation side breathing circuit 125.

Fig. 9(B) is an explanatory diagram of a conventional humidifier 105. The humidifier 105 stores liquid (water) 155 inside the housing. The liquid (water) 155 is heated and evaporated by a heating element 150. The heating element 150 has, for example, an electrical resistor (not shown) and is heated by passing a current from a power source 160.

Specifically, the supply gas flowing in from the supply gas inlet 115 contains water vapor that has evaporated from the surface of the liquid (water) 155 in the humidification space 145, and after being humidified, is sent from the supply gas outlet 120 through the breathing circuit to the airway of the user U. At this time, the outlet temperature of the supply gas is measured by the supply gas outlet temperature measuring unit 140, and the power input to the heating element 150 is controlled so that the appropriate temperature and humidity are achieved in the airway of the user U.

Special Publication No. 2009-504277

However, with the technology described in Patent Document 1, a sufficient amount of water vapor cannot be generated unless the temperature of the water in the entire water tank is raised. This results in a large amount of energy consumption, and it takes a long time before humidification is possible. Furthermore, since a large amount of hot water must be stored, it is difficult to reduce the size of the device. Furthermore, since a large amount of hot water must be stored, there is a high risk that hot water will leak if the humidifier is knocked over, resulting in burns to the user. It is thought that respiratory support devices will be used more frequently in home medical care in the future, and in that sense, they are inconvenient for family members other than medical professionals to use.

The present invention was made in consideration of the above problems, and aims to provide a humidifier and respiratory assistance device that can be made small and lightweight and can quickly and sufficiently humidify the stored water without heating the entire water.

(1) The present invention provides a humidifier that humidifies a gas supply to be supplied to a user, comprising: a heat generating unit that heats and vaporizes a liquid used to humidify the gas supply; a liquid supply unit that supplies the liquid to the heat generating unit; a power source that supplies energy to the heat generating unit; an input power measuring unit that measures the input power supplied from the power source to the heat generating unit; a heat generating control unit that controls the input power by referring to the temperature inside the humidifier or the temperature inside a breathing circuit connected to the humidifier; a target input power calculation unit that calculates a target target input power from a target heating and humidification state for the gas supply; and a liquid supply control unit that controls the amount of liquid supplied based on the difference between the measured input power and the target input power.

The invention described in (1) above provides the extremely excellent effect of enabling high-speed heating and humidification control and humidification control with a minimum supply of liquid by independently controlling the input power by referring to the temperature in the breathing circuit connected to the humidification device, calculating the target input power by calculating the target target input power from the target heating and humidification state for the supplied gas, and controlling the amount of liquid supplied based on the difference between the input power and the target input power.

(2) The present invention provides a humidifier as described in (1) above, which includes an outside air temperature measuring unit that measures the outside air temperature, which is the temperature of the environment in which the user is present; an outside humidity measuring unit that measures the outside humidity, which is the humidity of the environment in which the user is present; and an air supply gas outlet temperature measuring unit that is provided near an air supply gas outlet, which is the outlet through which the air supply gas is sent to a breathing circuit, and measures the outlet temperature, which is the temperature of the air supply gas sent to the breathing circuit; the heat generation control unit controls the input power to the heat generation unit based on the difference between the outlet temperature and a preset target temperature; and the target input power calculation unit calculates the target input power based on at least the outside air temperature, the outside humidity, and the outlet temperature.

According to the invention described in (2) above, the power input to the heat generating unit is determined based on the environmental variables of the user's environment, which has the excellent effect of enabling quick and sufficient heating and humidification with a minimum amount of energy and liquid (amount of water).

(3) The present invention relates to a humidifier as described in (1) or (2) above, further comprising a liquid supply amount adjustment unit that adjusts the amount of the liquid supplied by the liquid supply unit, and the liquid supply control unit controls the liquid supply amount adjustment unit.

According to the invention described in (3) above, only the amount of liquid (water) required for heating and humidification can be supplied to the heat generating section, so liquid water does not accumulate, preventing bacterial growth and providing a humidifier that is also excellent in terms of hygiene.

(4) The present invention provides a respiratory assistance device including a humidifier device according to any one of (1) to (3) above.

The invention described in (4) above has the excellent effect of providing a small, lightweight respiratory assistance device equipped with a humidifier that can quickly heat and humidify with a minimum amount of liquid (water) and optimal input power.

(5) The present invention provides a humidifier for humidifying a gas to be sent to a user, the humidifier comprising a heat generating unit for heating and vaporizing a liquid used for humidifying the gas to be sent to the user, a liquid supply unit for supplying the liquid to the heat generating unit, a power source for supplying energy to the heat generating unit, and an input power measuring unit for measuring the input power input from the power source to the heat generating unit, the humidification method comprising a heat generating control step for controlling the input power by referring to a temperature inside the humidifier or a temperature inside a breathing circuit connected to the humidifier, a target input power calculation step for calculating a target target input power from a target heating and humidification state for the gas to be sent, and a liquid supply control step for controlling the amount of liquid supplied based on a difference between the measured input power and the target input power.

The invention described in (5) above provides the extremely excellent effect of enabling high-speed heating and humidification control and humidification control with a minimum supply of liquid by independently controlling the input power by referring to the temperature in the breathing circuit connected to the humidification device, calculating the target input power by calculating the target target input power from the target heating and humidification state for the supplied gas, and controlling the liquid supply unit based on the difference between the input power and the target input power.

(6) The present invention provides the humidification method described in (5) above, characterized in that in the humidifier, which includes an outside air temperature measuring unit that measures the outside air temperature, which is the temperature of the environment in which the user is present, an outside humidity measuring unit that measures the outside humidity, which is the humidity of the environment in which the user is present, and a gas outlet temperature measuring unit that is provided near a gas outlet that is the outlet through which the gas is sent to a breathing circuit and that measures the outlet temperature, which is the temperature of the gas sent to the breathing circuit, the heat generation control step controls the input power to the heat generation unit based on the difference between the outlet temperature and a preset target temperature, and the target input power calculation step calculates the target input power based on at least the outside air temperature, the outside humidity, and the outlet temperature.

According to the invention described in (6) above, the power input to the heat generating unit is determined based on the environmental variables of the user's environment, which has the excellent effect of enabling quick and sufficient heating and humidification with a minimum amount of energy and liquid (amount of water).

(7) The present invention provides the humidification method according to (5) or (6) above, further comprising a liquid supply amount adjustment unit that adjusts the amount of the liquid supplied by the liquid supply unit, and the liquid supply control step controls the liquid supply amount adjustment unit.

According to the invention described in (7) above, liquid (water) can be supplied to the heating element in the amount required for heating and humidification, so liquid water does not accumulate, preventing bacterial growth and providing a humidifier that is also excellent in terms of hygiene.

(8) The present invention provides a respiratory assistance method including the humidification method described in any one of (5) to (7) above.

The invention described in (8) above provides the extremely excellent effect of enabling high-speed heating and humidification control and humidification control with a minimum of liquid supply by independently controlling the input power by referring to the temperature in the breathing circuit connected to the humidification device, calculating the target input power by calculating the target target input power from the target heating and humidification state for the supplied gas, and controlling the liquid supply unit based on the difference between the input power and the target input power.

(9) The present invention provides a humidifier comprising a housing having a humidification space for adding water vapor to the gas to be sent to a user, a heat generating section that generates heat by obtaining electrical energy using electromagnetic induction is disposed in the humidification space, and the humidifier further comprises a coil that transmits energy to the heat generating section by the electromagnetic induction, an insulating section that spatially separates the heat generating section and the coil to prevent electrical contact, and a liquid supply section that supplies liquid to be evaporated into the water vapor to the heat generating section.

According to the invention described in (9) above, it is possible to configure a humidifier in which a humidifying unit that vaporizes liquid (water) into water vapor, specifically a heat generating unit, and an energy supply unit that supplies energy to the heat generating unit, specifically a coil, can be spatially separated. Therefore, it is possible to replace only the humidifying unit, which contains moisture and may cause problems such as bacteria growth, providing the excellent effect of easy maintenance.

(10) The present invention provides the humidifier described in (9) above, characterized in that the liquid supply unit supplies the liquid in a manner that keeps the liquid from accumulating in the vicinity of the heat generating unit.

According to the invention described in (10) above, liquid (water) does not remain inside the humidifier, which has the excellent effect of making it difficult for bacteria to grow and making it easier to maintain good hygienic conditions.

(11) The present invention provides a humidifier as described in (9) or (10) above, characterized in that the heat generating portion is cylindrical and the coil is disposed via the insulating portion.

According to the invention described in (11) above, the coil that applies energy to the heat generating part using electromagnetic induction is electrically insulated from the heat generating part by an insulating part, which has the excellent effect of reducing the possibility of accidents such as short circuits.

(12) The present invention provides a humidifier as described in (11) above, characterized in that the insulating part is cylindrical, the insulating part is disposed on the inner periphery of the heat generating part, and the coil is disposed on the inner periphery of the insulating part.

According to the invention described in (12) above, a coil is disposed inside the cylindrical heat generating part, which has the excellent effect of efficiently transferring energy from the coil to the heat generating part by using the electromagnetic induction phenomenon.

(13) The present invention provides a humidifier as described in (12) above, characterized in that the cylindrical central axis of the heat generating portion is arranged to face in a non-vertical direction.

The invention described in (13) above makes it easy to increase the surface area of the heat generating part that comes into contact with the gas to be heated and humidified, which has the excellent effect of providing a small humidifier that is capable of sufficient heating and humidification.

(14) The present invention provides a humidifier according to any one of (9) to (13) above, characterized in that the heat generating portion is a porous metal body that contains metal and is configured to be porous.

The porous metal body has electrical conductivity. According to the invention described in (14) above, a current flows from the coil to the porous metal body due to electromagnetic induction, which generates resistance heating, and has the excellent effect of efficiently vaporizing water.

(15) The present invention provides a humidifier according to any one of (9) to (14) above, characterized in that the coil and the heat generating portion are magnetically coupled by a magnetic material.

According to the invention described in (15) above, the coil and the heat generating part through which current flows by electromagnetic induction are efficiently magnetically coupled, which has the excellent effect of increasing the efficiency of energy transfer from the coil to the heat generating part.

(16) The present invention provides a respiratory assistance device including a humidification device as described in any one of (9) to (15) above.

The invention described in (16) above has the remarkable advantage of making it possible to reduce the size and weight of the humidifier, and to quickly and sufficiently humidify the water without heating the entire water stored in it.

The humidifier and respiratory assistance device according to claims 1 to 8 of the present invention provide the excellent effects of realizing a humidifier that is easy to maintain, hygienic, small, lightweight, and capable of rapid heating and humidification, and a respiratory assistance device equipped with such a humidifier.

1 is a conceptual diagram of a respiratory assistance device according to an embodiment of the present invention. 1A is an explanatory diagram of the inside of a housing of a humidifier in a respiratory assistance device according to an embodiment of the present invention, and FIG. 1A is an explanatory diagram of a humidifier in a respiratory assistance apparatus according to an embodiment of the present invention, and FIG. 1B is an explanatory diagram of a humidifier in a respiratory assistance apparatus according to a first modified embodiment of the present invention. (A) An explanatory diagram showing the operation of separating an energy supply unit and a humidifying unit constituting a humidifying device in a respiratory assistance device according to an embodiment of the present invention. (B) An explanatory diagram showing the operation of separating an energy supply unit and a humidifying unit constituting a humidifying device in a respiratory assistance device according to a first modified embodiment of the present invention. (C) An explanatory diagram showing a mode in which the humidifying space in the housing is opened and only the humidifying unit is separated for maintenance. 13A is an explanatory diagram illustrating the inside of a housing of a humidifier in a respiratory assistance apparatus according to a second modified embodiment of the present invention, and FIG. 4 is a flow chart illustrating an algorithm for controlling the outlet temperature of the insufflated gas in a humidifier in a respiratory assistance device. 11 is a flowchart illustrating an algorithm for calculating and setting a target input power in real time in a humidifier in a respiratory assistance device. 10 is a flowchart illustrating an algorithm for controlling the amount of liquid (water) supplied from the power supply to the heat generating portion. 1A is a schematic diagram of a conventional respiratory assistance device, and FIG. 1B is an explanatory diagram of a conventional humidification device.

The following describes an embodiment of the present invention with reference to the attached drawings.

Figures 1 to 8 show an example of a form for implementing the invention, and in the figures, parts with the same reference numerals represent the same items. Note that in each figure, some components have been omitted as appropriate to simplify the drawings. Additionally, the size, shape, thickness, etc. of components have been exaggerated as appropriate.

Figure 1 is a conceptual diagram of a respiratory assistance device 1 according to an embodiment of the present invention. The respiratory assistance device 1, which assists the breathing of a user U, includes a blower 10 that sends out the supply gas, a medical gas cylinder 13 that supplies medical gas used for medical treatment and other medical purposes, a humidifier 9 that humidifies the supply gas, a breathing circuit 5 that guides the supply gas to the user U, and a respiratory assistance interface 3 that is disposed near the nose and/or mouth of the user U and guides the supply gas.

The blower 10 draws in air from the intake port 40 and delivers it to the humidifier 30. Medical gas supplied from the medical gas cylinder 13 is also delivered to the humidifier 30. In other words, the delivered gas may be a mixture of the air drawn in from the intake port 40 and the medical gas.

The medical gas may be, for example, oxygen gas.

The humidifier 9 has a housing 30, a power source 29, an input power measuring unit 31 that measures the input power input from the power source 29 to the heat generating unit (porous metal) 59 (see FIG. 2(A) described later), a liquid supplying unit 68 that supplies liquid (water) to the heat generating unit (porous metal) 59, an external environmental variable measuring unit 27 that measures the environmental variables of the environment in which the user is located, and a control unit 21 that controls the humidifier 9. In addition, an air supply gas outlet temperature measuring unit 7 that measures the temperature of the air supply gas sent to the breathing circuit 5 is disposed at the air supply gas outlet 35 from which the air supply gas is sent from the housing 30 (see FIG. 2(A) described later).

The location of this "outlet" is not particularly limited and may be anywhere downstream of the heat generating portion (porous metal body) 59.

The power input from the power source 29 is the power sent directly to the coil 57, but the above expression is used because the electrical energy is input to the heat generating part (porous metal body) 59 (see FIG. 2(A) described below) through the electromagnetic induction phenomenon. Therefore, the input power measuring unit 31 may measure either the power input to the coil 57 or the energy transmitted to the heat generating part (porous metal body) 59.

The heat generating part 59 is a porous metal body that contains metal and is configured to have many pores. The heat generating part (porous metal body) 59 may have a mesh structure in which metal fibers are compressed.

The control device 21 includes a heat generation control unit 15 that controls the input power by referring to the temperature inside the humidifier 9 or inside the breathing circuit 5 connected to the humidifier 9, a target input power calculation unit 17 that calculates a target input power from a target heating and humidification state for the supplied gas, and a liquid supply control unit 19 that controls the amount of liquid (see FIG. 3 described below) based on the difference between the measured input power and the target input power.

The external environmental variable measuring unit 27 has an external air temperature measuring unit 23 that measures the temperature of the environment in which the respiratory assistance device 1 is installed, and an external humidity measuring unit 25 that measures the humidity of the environment in which the respiratory assistance device 1 is installed. The external air temperature measuring unit 23 may be, for example, a resistance thermometer. The external humidity measuring unit 25 may be, for example, a bimetal type, or a digital type using a moisture-sensitive agent and a comb-shaped electrode.

The control device 21 is composed of a CPU, RAM, ROM, etc., and performs various controls. The CPU is a so-called central processing unit, and executes various programs to realize various functions. The RAM is used as the working area and storage area of the CPU, and the ROM stores the operating system and programs executed by the CPU.

The control device 21 may control the operation of the entire respiratory assistance device 1.

2(A) is an explanatory diagram of the inside of the housing 30 of the humidifier 9 in the respiratory assistance device 1 according to the embodiment of the present invention. The housing 30 includes a gas inlet 47 through which the gas is fed, a gas outlet 35 through which the gas is fed to the breathing circuit 5 (see FIG. 1), a coil 57 that generates a magnetic field, a heat generating part (porous metal) 59, an insulating part 61 that electrically insulates the coil 57 from the heat generating part (porous metal) 59, ferrite 55 that is a magnetic material that increases the efficiency of the magnetic coupling between the coil 57 and the heat generating part (porous metal) 59, and a straightening plate 51 that changes the flow of the gas so that the gas comes into contact with the heat generating part (porous metal) 59 for a sufficiently long time. The gas is heated and humidified by the heated steam generated in the heat generating part (porous metal) 59 flowing into the humidification space 49.

Figure 2 (B) is a cross-sectional view of the humidifier 9. The supply gas is taken into the housing 30 from the supply gas inlet 47, and the flow is changed by the straightening plate 51. For example, the supply gas travels along a path such as the humidification and heating path 50 shown by the dashed line in Figure 2 (B), specifically, along a path including an entrance side path 50A leading from the supply gas inlet 47 to the heat generating part (metallic porous body) 59, a heat generating part side path 50B near the heat generating part (metallic porous body) 59, and an exit side path 50C leading from the heat generating part (metallic porous body) 59 to the supply gas outlet 35. After being heated and humidified in the humidification space 49 by containing the heated steam generated in the heat generating part (metallic porous body) 59, the supply gas is sent out from the supply gas outlet 35 to the breathing circuit 5.

The humidifier 9 includes a housing 30 having a humidifier space 49 in which water vapor is added to the gas sent to the user U, and the humidifier space 49 includes a heat generating section 59, a coil 57, and an insulating section 61. The humidifier 9 further includes a liquid supply section 63 (see FIG. 3 described later) that supplies the heat generating section 59 with liquid to be vaporized into water vapor.

Specifically, the heat generating part (metallic porous body) 59 is cylindrical in shape with a circular cross section, contains metal, and is electrically conductive overall, but has an electrical resistance value that causes heating when a current induced by electromagnetic induction flows from the coil 57. The coil 57 is a metal wire wound in a spiral shape and is disposed along the outer periphery of the ferrite 55. The coil 57 has high electrical conductivity. The insulating part 61 is disposed between the heat generating part (metallic porous body) 59 and the coil 57, electrically insulating them from each other and also serving as an isolation wall that spatially isolates the coil 57 from the liquid (water) supplied from the liquid supply device 68 to the heat generating part (metallic porous body) 59 and the water vapor that evaporates from the liquid. The insulating part 61 may be glass or synthetic resin.

The coil 57 is also arranged on the inner circumference of the heating part 59 via an insulating part 61.

The insulating part 61 is cylindrical, and is arranged on the inner periphery of the heat generating part 59, and the coil 57 is arranged on the inner periphery of the insulating part 61.

It is also possible to arrange the cylindrical central axis of the heating section 59 so that it faces in a non-vertical direction. Here, the basic position is shown as a horizontal central axis, but an advantage of this humidifier is that it can humidify and heat even if the position is changed.

Figure 3 (A) is an explanatory diagram of the humidification device 9 in the respiratory assistance device 1 according to an embodiment of the present invention.

In this modified embodiment, ferrite 55 is provided on the inner circumference side of coil 57 to enhance the magnetic coupling between heat generating portion (porous metal body) 59 and coil 57. Also, part of housing 30 may serve as insulating portion 61 (see FIG. 2(A) above). Housing 30 may be made of a synthetic resin such as ABS resin.

The power supplied to the coil 57 is applied from the power source 29 through the power line 69, and the power source 29 is controlled by the heat generation control unit 15. The value of the supplied power is measured in real time by the supplied power measurement unit.

The liquid (water) is supplied from the liquid supply device 68 to the heat generating part (porous metal body) 59. Specifically, the liquid is supplied from the liquid storage part 67 to the heat generating part (porous metal body) 59 through the liquid supply part 63. The liquid (water) is supplied little by little from the end of the liquid supply part 63 to the inner peripheral surface of the heat generating part (porous metal body) 59. The liquid supply part 63 is tubular, and it is desirable that the end of the liquid supply part 63 is arranged along the inner peripheral surface of the heat generating part (porous metal body) 59. The amount of liquid (water) supplied is adjusted by the liquid amount adjustment part 65, which may be, for example, a piezoelectric pump. The liquid amount adjustment part 65 is controlled by the liquid supply control part 19 (see FIG. 1).

The liquid supply unit 19 supplies liquid so as to maintain a state in which liquid does not accumulate near the heat generating unit 59. In other words, the liquid is supplied in an amount that does not exceed the maximum amount of liquid that the heat generating unit (porous metal) 59 can vaporize.

Figure 4 (A) is an explanatory diagram showing the operation of separating the energy supply unit 73 and the humidification unit 71 constituting the humidification device 9 in the respiratory assistance device 1 according to an embodiment of the present invention. In the state of performing heating and humidification, the energy supply unit 73 including the ferrite 55 and the coil 57 is placed in a recess of the housing 30 in which the heat generating unit (metallic porous body) 59 is disposed, and the coil 57 and the heat generating unit (metallic porous body) 59 form a magnetic circuit, enabling the heat generating unit (metallic porous body) 59 to be heated by electromagnetic induction (see the left diagram of Figure 4 (A)). When performing maintenance, specifically when replacing the humidification unit 71 having the heat generating unit (metallic porous body) 59, the energy supply unit 73 and the humidification unit 71 can be spatially separated (see the right diagram of Figure 4 (A)).

Figure 4(C) is an explanatory diagram showing the operation of opening the humidification space 49 in the housing 30 and isolating only the humidification unit 71 (heat generating unit (porous metal) 59). The humidification device 30 comprises a main body 30A and a lid 30B, and during maintenance, specifically when replacing the heat generating unit (porous metal) 59, the heat generating unit (porous metal) 59 can be easily removed and replaced by opening the lid 30B (see the right diagram in Figure 4(C)).

Figure 3 (B) is an explanatory diagram of the humidification device 9 in the respiratory assistance device 1 according to the first modified embodiment of the present invention.

In this modified embodiment, a U-shaped ferrite 55 is provided to close the magnetic circuit between the heat generating portion (porous metal) 59 and the coil 57 as much as possible to enhance magnetic coupling. Also, a part of the housing 30 may serve as the insulating portion 61 (see FIG. 2(A) above). The housing 30 may be made of a synthetic resin such as ABS resin.

The power supplied to the coil 57 is applied from the power source 29 through the power line 69, which is controlled by the heat generation control unit 15. The value of the supplied power is measured in real time by the supplied power measurement unit.

The liquid (water) is supplied to the heat generating part (porous metal body) 59 from the liquid storage part 67 through the liquid supply part 63. The amount of liquid (water) supplied is controlled by the liquid amount adjustment part 65, which may be, for example, a piezoelectric pump. The liquid amount adjustment part 65 is controlled by the liquid supply control part 19 (see FIG. 1).

The liquid supply unit 19 supplies liquid so as to maintain a state in which liquid does not accumulate near the heat generating unit 59. The supply of liquid to the heat generating unit (porous metal body) 59 is the same as in FIG. 3(A), so a description thereof is omitted.

FIG. 4(B) is an explanatory diagram showing the operation of separating the energy supply unit 73 and the humidifier unit 71 constituting the humidifier 9 in the respiratory assistance device 1 according to the first modified embodiment of the present invention.
In the state where heating and humidification is performed, the energy supply unit 73 including the ferrite 55 and the coil 57 is disposed in a recess of the housing 30 in which the heat generating unit (porous metal) 59 is disposed, and the coil 57 and the heat generating unit (porous metal) 59 form a magnetic circuit, enabling heating of the heat generating unit (porous metal) 59 by electromagnetic induction (see the left diagram in FIG. 4(B)). When performing maintenance, specifically when replacing the humidifying unit 71 having the heat generating unit (porous metal) 59, the energy supply unit 73 and the humidifying unit 71 can be spatially separated (see the right diagram in FIG. 4(B)).

Since liquid (water) is supplied to the humidifier 71, bacteria may grow, so it is advisable to replace it periodically. Since the housing 30 can be easily separated into the energy supply unit 73 and the humidifier 71, maintenance is simplified as only the humidifier 71 can be replaced with a new one.

Figure 5 (A) is an explanatory diagram illustrating the inside of the housing 30 of the humidifier 9 in the respiratory assistance device 1 according to a second modified embodiment of the present invention. This modified embodiment includes a heating section 75 having a heat generating section (porous metal) 59, and a humidifier section 77 similarly having a heat generating section (porous metal) 59. The supply gas taken in from the supply gas inlet 47 is heated by the heating section 75 to which no liquid is supplied, humidified by the humidifier section 77 to which liquid is supplied, and then sent out from the supply gas outlet 35 to the breathing circuit 5 (see Figure 1). The supply of liquid in the humidifier section 77 is the same as in the embodiment of the present invention, so a detailed description will be omitted.

Figure 5 (B) is a cross-sectional view of the housing of the humidifier 9. The heating unit 75 includes a heating coil 79 and a heating heat generating unit 83. The humidifier 77 includes a humidifier coil 81 and a humidifier heat generating unit 85. The heating unit 75 may be controlled according to the algorithm shown in Figure 6, which will be described later, and the humidifier 77 may be controlled according to the algorithms shown in Figures 7 and 8, which will be described later.

This modified embodiment has the advantage of being able to control temperature and humidity independently.

In this modified embodiment, the heating unit 75 is located upstream of the air supply and the humidifying unit 77 is located downstream, but the humidifying unit 77 may be located upstream of the air supply and the heating unit 75 may be located downstream.

Liquid may also be supplied to the heating section 75 as well as the humidifying section 77, so that the heating section 75 heats and humidifies the supply gas at the same time as the humidifying section 77.

In general, in the respiratory assistance device 1, it is desirable for the gas delivered to the nose and mouth of the user U to have values predetermined by a doctor, such as a temperature of 37°C and a relative humidity of 100%. However, if the above-mentioned predetermined values are present at the gas delivery outlet 35 of the humidifier 9, heat will be lost as the gas is delivered through the respiratory circuit 5, causing the temperature of the gas to drop and the relative humidity to drop. The degree of this heat loss will vary depending on the ambient temperature.

Therefore, it is necessary to calculate the target temperature and target humidity (target absolute humidity) of the supply gas at the supply gas outlet 35 taking into account the environmental variables of the environment in which the respiratory assistance device 1 is placed, i.e., the outside temperature and humidity, and the degree of heat loss in the breathing circuit 5, and then determine the input power from the power source 29 and the amount of liquid (water) supplied so as to achieve these.

In the humidifier 9 in the respiratory assistance device 1 according to an embodiment of the present invention, when the water required to achieve the target absolute humidity is supplied, the target input power calculation unit 17 calculates the target input power taking into account the power required for vaporization in the heat generating unit (metallic porous body) 59.

Specifically, the humidifier 9 in the respiratory assistance device 1 according to this embodiment is a humidifier that humidifies the supply gas to be supplied to the user U, and includes a heat generating unit 59 that heats and vaporizes the liquid used to humidify the supply gas, a liquid supply unit 63 that supplies the liquid to the heat generating unit 59, a power source 29 that supplies energy to the heat generating unit 59, an input power measuring unit 31 that measures the input power supplied from the power source 29 to the heat generating unit 59, a heat generating control unit 15 that controls the input power by referring to the temperature inside the humidifier 9 or the breathing circuit 5 connected to the humidifier 9, a target input power calculation unit 17 that calculates a target target input power from a target heating and humidification state for the supply gas, and a liquid supply control unit 19 that controls the amount of liquid supplied based on the difference between the measured input power and the target input power.

The humidifier 9 in the respiratory assistance device 1 according to this embodiment includes an outside air temperature measuring unit 23 that measures the outside air temperature, which is the temperature of the environment in which the user U is located, an outside humidity measuring unit 25 that measures the outside humidity, which is the humidity of the environment in which the user U is located, and an air gas outlet temperature measuring unit 7 that is provided near the air gas outlet 35, which is the outlet through which the air gas is sent to the breathing circuit 5 (see FIG. 1), and measures the air gas outlet temperature, which is the temperature of the air gas sent to the breathing circuit 5. The heat generation control unit 15 controls the power input to the heat generation unit 59 based on the difference between the outlet temperature and a preset target temperature, and the target power input calculation unit 17 calculates the target power input based on the values of the outside air temperature, the outside humidity, and the outlet temperature.

Furthermore, in the humidifier 9 of the respiratory assistance device 1 according to this embodiment, the liquid supply control unit 19 controls the amount of the liquid supplied to the heat generating unit 59 by the liquid supply amount control unit 65, which changes the amount of the liquid supplied.

Figure 6 is a flowchart explaining the algorithm for controlling the outlet temperature of the supply gas in the humidifier 9 of the respiratory assistance device 1.

First, the air supply gas outlet temperature (hereinafter referred to as outlet temperature) measured by the air supply gas outlet temperature measuring unit 7 (see FIG. 1) arranged in the air supply gas outlet 35 of the humidifier 9 is measured (step S1). It is determined whether there is a difference between the outlet temperature and the target temperature calculated and set in advance (step S2). If there is no difference, the heat control unit 15 (see FIG. 1) controls to maintain the input power measured by the input power measuring unit 31 (see FIG. 1) (step S6). If there is a difference, it is determined whether the outlet temperature is higher than the target temperature calculated and set in advance (step S3). If it is higher, the heat control unit 15 controls to lower the input power (step S4). If it is lower, the heat control unit 15 controls to increase the input power (step S5). After completing the above-mentioned steps S4, S5, and S6, the process returns to step S1.

By using the above feedback control, the input power is always controlled so that the gas outlet temperature is stabilized at the target temperature.

The control of the input power by the heat control unit 15 may be, for example, PID control that controls the current value. It is also preferable that the specific power control is PWM control.

Figure 7 is a flowchart explaining an algorithm for calculating and setting the current target input power in real time in a humidifier in a respiratory assistance device.

First, the outside air temperature is measured by the outside air temperature measuring unit 23 (see FIG. 1), and the outside humidity is measured by the outside air humidity measuring unit 25 (see FIG. 1). Then, the target absolute humidity at the gas supply outlet 35 is determined based on the outside air temperature, outside humidity, the flow rate of the gas supply, heat loss in the breathing circuit, etc. (step U1). Next, the amount of water required to achieve this absolute humidity is calculated, and the target input power to be input from the power source 29 to the heating unit (porous metal body) 59 is calculated to raise the temperature of the water and vaporize it, and to raise the temperature of the flowing gas supply (step U2). The calculated value is then set as the current target input power (step U3). This current target input power is used in the algorithm shown in FIG. 8, which will be described later.

By constantly repeating the above operations, it is possible to calculate and set the optimal target input power in real time.

Figure 8 is a flowchart that explains the algorithm for controlling the amount of liquid (water) supplied from the power source 29 to the heating element 59.

First, the input power measurement unit 31 measures the input power to the heat generating unit (metallic porous body) 59 (step T1). Next, it is determined whether there is a difference between the current input power and the current target input power (step T2). If there is no difference, the liquid supply control unit 19 controls the liquid amount adjustment unit 65 (see FIG. 3) to maintain the amount of liquid supplied (step T6). If there is a difference, it is determined whether the value of the current input power is greater than the current target input power calculated and set in advance (step T3). If it is greater, the liquid supply control unit 19 controls the liquid amount adjustment unit 65 to decrease the amount of liquid supplied (step T4). If it is smaller, the liquid supply control unit 19 controls the liquid amount adjustment unit 65 to increase the amount of liquid supplied (step T5). After completing the above-mentioned steps T4, T5, and T6, the process returns to step T1.

By controlling the amount of liquid supplied in this way as a feedback, the input power is controlled to be stable at the target input power.

In the humidifier 9 of the respiratory assistance device 1 according to this embodiment, the control shown in FIG. 6 and the control shown in FIG. 8 are controlled independently.

In the control of the humidifier 9 in the respiratory assistance device 1 according to the present invention shown in Figures 6 to 8, the input power of the power source 29 is determined solely by temperature control based on the outlet temperature of the air supply gas at the air supply gas outlet 35. Therefore, the input power is controlled to compensate for the drop in outlet temperature that occurs when liquid (water) is supplied. Meanwhile, the target input power is updated in real time based on the external environment, the flow rate of the air supply gas, the outlet temperature, etc., and the amount of liquid supplied is controlled so that the actual input power becomes the actual target input power. In other words, it is characterized by the fact that it is not an algorithm that directly controls the input power for humidification.

According to the humidifier 9 in the respiratory assistance device 1 according to the embodiment of the present invention, the humidifier 9 can be configured in which the humidifier 71, which vaporizes liquid (water) into water vapor, specifically the heat generating unit 59, and the energy supply unit 73, which supplies energy to the heat generating unit 59, specifically the coil 57, can be spatially separated. Therefore, it is possible to replace only the humidifier 71, which contains moisture and may cause problems such as bacteria growth, providing the excellent effect of easy maintenance.

The humidifier 9 in the respiratory assistance device 1 according to the embodiment of the present invention has the excellent effect of preventing bacteria from multiplying and making it easier to maintain good hygienic conditions, since liquid (water) does not remain inside the humidifier 9.

The humidifier 9 in the respiratory assistance device 1 according to the embodiment of the present invention has the excellent effect of reducing the possibility of accidents such as short circuits because the coil 57, which uses electromagnetic induction to apply energy to the heat generating unit 59, is electrically insulated from the heat generating unit 59 by the insulating unit 61.

The humidifier 9 in the respiratory assistance device 1 according to the embodiment of the present invention has a coil 57 disposed inside the cylindrical heat generating part 59, which has the excellent effect of efficiently transferring energy from the coil 57 to the heat generating part 59 using the electromagnetic induction phenomenon.

The humidifier 9 in the respiratory assistance device 1 according to the embodiment of the present invention makes it easy to increase the surface area of the heat generating section 59 that comes into contact with the gas to be heated and humidified, which has the excellent effect of providing a small humidifier 9 that is capable of sufficient heating and humidification.

The porous metal body has electrical conductivity. According to the humidifier 9 in the respiratory assistance device 1 according to the embodiment of the present invention, a current flows from the coil 57 to the porous metal body 59 due to the electromagnetic induction phenomenon, which generates resistive heating, thereby providing the excellent effect of efficiently vaporizing water.

The humidifier 9 in the respiratory assistance device 1 according to the embodiment of the present invention efficiently magnetically couples the coil to the heat generating unit 59 through which current flows by electromagnetic induction, providing the excellent effect of increasing the efficiency of energy transfer from the coil 57 to the heat generating unit 59.

The humidifier 9 in the respiratory assistance device 1 according to the embodiment of the present invention has the remarkable advantage that it is possible to reduce the size and weight of the humidifier, and that it is possible to humidify the water quickly and sufficiently without heating the entire water stored in it.

The humidifier 9 in the respiratory assistance device 1 according to the embodiment of the present invention independently controls the input power by referring to the temperature in the breathing circuit 5 connected to the humidifier 9, calculates the target input power by calculating the target input power from the target heating and humidification state of the supplied gas, and controls the liquid amount adjustment unit 65 based on the difference between the input power and the target input power, thereby achieving the extremely excellent effect of enabling high-speed heating and humidification control and humidification control with a minimum supply of liquid.

The humidifier 9 in the respiratory assistance device 1 according to the embodiment of the present invention determines the power input to the heat generating unit 59 based on the environmental variables of the environment in which the user U is located, which provides the excellent effect of enabling quick and sufficient heating and humidification with a minimum amount of energy and liquid (amount of water).

The humidifier 9 in the respiratory assistance device 1 according to the embodiment of the present invention can supply liquid (water) to the heat generating section 59 in the amount required for heating and humidification, which prevents liquid water from accumulating and inhibits bacterial growth, providing an excellent humidifier that is also hygienic.

The respiratory assistance device 1 according to the embodiment of the present invention has the excellent effect of providing a small, lightweight respiratory assistance device equipped with a humidifier 9 that can perform quick heating and humidification with a minimum amount of liquid (water) and optimal input power.

The humidifier and respiratory assistance device according to the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

LIST OF SYMBOLS 1 Respiratory support device 3 Interface 5 Respiratory circuit 7 Gas supply outlet temperature measuring unit 9 Humidifier 10 Blower 13 Medical gas cylinder 15 Heat generation control unit 17 Target input power calculation unit 19 Liquid supply control unit 21 Control device 23 Outside air temperature measuring unit 25 Outside humidity measuring unit 27 External environmental variable measuring unit 29 Power supply 30 Housing 31 Input power measuring unit 35 Gas supply outlet unit 40 Intake port 47 Gas supply inlet unit 49 Humidification space 50 Humidification and heating path 51 Straightening plate 55 Ferrite 57 Coil 59 Heat generation unit (metallic porous body)
61 Insulation section 63 Liquid supply section 65 Liquid amount adjustment section 67 Liquid storage section 68 Liquid supply device 69 Power supply line 71 Humidification section 73 Energy supply section 75 Heating section 77 Humidification section 79 Heating coil 81 Humidification coil 83 Heating heat generating section 85 Humidification heat generating section 101 Respiratory support storage 105 Humidification device 110 Ventilator 115 Breathing gas inlet section 120 Breathing gas outlet section 125 Exhalation side breathing circuit 127 Inhalation side breathing circuit 130 Corrugated tube 135 Interface 140 Breathing gas outlet temperature measuring section 145 Humidification space 150 Heating element 155 Liquid (water)
160 Power supply U User

Claims (8)

A humidifier for humidifying a gas to be sent to a user, comprising:
A heating unit that heats and vaporizes a liquid used to humidify the gas supplied;
a liquid supply unit that supplies the liquid to the heat generating unit;
A power source that supplies energy to the heat generating portion;
an input power measuring unit that measures an input power input from the power source to the heat generating unit;
a heat generation control unit that controls the input power by referring to a temperature in the humidifier or a temperature in a breathing circuit connected to the humidifier;
a target input power calculation unit that calculates a target input power based on a target heating and humidifying state of the gas to be supplied;
A humidifier comprising: a liquid supply control unit that controls an amount of liquid supplied based on a difference between the measured input power and the target input power. An outside air temperature measuring unit for measuring an outside air temperature, which is the temperature of the environment in which the user is present;
An external humidity measuring unit for measuring external humidity, which is the humidity of the environment in which the user is present;
a gas outlet temperature measuring unit that is provided near a gas outlet through which the gas is sent to a breathing circuit and that measures an outlet temperature, which is the temperature of the gas sent to the breathing circuit;
the heat generation control unit controls the power input to the heat generation unit based on a difference between the outlet temperature and a preset target temperature,
The humidifier according to claim 1 , wherein the target input power calculation unit calculates the target input power based on at least values of the outside air temperature, the outside humidity, and the outlet temperature. The humidifier according to claim 1 or 2, further comprising a liquid supply amount adjustment unit that adjusts the amount of the liquid supplied by the liquid supply unit, and the liquid supply control unit controls the liquid supply amount adjustment unit. A respiratory assistance device comprising a humidifier according to any one of claims 1 to 3. A heating unit that heats and vaporizes a liquid used to humidify the gas sent to the user;
a liquid supply unit that supplies the liquid to the heat generating unit;
A power source that supplies energy to the heat generating portion;
an input power measuring unit that measures an input power input from the power source to the heat generating unit;
In the humidifier for humidifying the supply gas,
a heat generation control step of controlling the input power by referring to a temperature in the humidifier or a temperature in a breathing circuit connected to the humidifier;
A target input power calculation step of calculating a target input power from a target heating and humidifying state of the gas to be supplied;
A humidification method comprising: a liquid supply control step of controlling an amount of liquid supplied based on a difference value between the measured input power and the target input power. An outside air temperature measuring unit for measuring an outside air temperature, which is the temperature of the environment in which the user is present;
An external humidity measuring unit for measuring external humidity, which is the humidity of the environment in which the user is present;
a gas outlet temperature measuring unit that is provided near a gas outlet through which the gas is sent to a breathing circuit and that measures an outlet temperature, which is the temperature of the gas sent to the breathing circuit;
the heat generation control step controls an input power to the heat generation unit based on a difference between the outlet temperature and a preset target temperature;
6. The humidification method according to claim 5, wherein the target input power calculation step calculates the target input power based on values of the outside air temperature, the outside humidity, and the outlet temperature. The humidifier according to claim 5 or 6, further comprising a liquid supply amount adjustment unit that adjusts the amount of the liquid supplied by the liquid supply unit, and the liquid supply control step controls the liquid supply amount adjustment unit. A respiratory assistance method including the humidification method according to any one of claims 5 to 7.

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