阅读说明：本技术 检测装置 (Detection device ) 是由 山本克行 上田直亚 河野好映 于 2019-01-18 设计创作，主要内容包括：本发明的一方面的检测装置是检测包含热性质的差在规定范围内的、不同种类物质的混合流体的特征的检测装置,所述检测装置具备：一个或多个的加热部,其加热所述混合流体；多个的温度检测部,其检测加热的所述混合流体的温度；流量计算部,其包含所述加热部、所述多个的温度检测部的至少一部分而构成,使用来自所述多个的温度检测部的至少一部分的输出计算所述混合流体的流量；对应关系存储部,其存储在规定流量下的来自所述温度检测部的输出与所述混合流体中的所述物质的混合比的对应关系；混合比计算部,其基于来自所述温度检测部的输出及所述对应关系,计算所述混合流体中的所述物质的混合比。(A detection device according to an aspect of the present invention is a detection device that detects a characteristic of a mixed fluid containing different types of substances having a difference in thermal properties within a predetermined range, the detection device including: one or more heating sections that heat the mixed fluid; a plurality of temperature detection units that detect the temperature of the heated mixed fluid; a flow rate calculation unit configured to include at least a part of the heating unit and the plurality of temperature detection units, and to calculate a flow rate of the mixed fluid using an output from at least a part of the plurality of temperature detection units; a correspondence relation storage unit that stores a correspondence relation between an output from the temperature detection unit and a mixing ratio of the substance in the mixed fluid at a predetermined flow rate; a mixing ratio calculation section that calculates a mixing ratio of the substances in the mixed fluid based on the output from the temperature detection section and the correspondence relationship.)

1. A detection device that detects a characteristic of a mixed fluid containing different types of substances having a difference in thermal properties within a predetermined range, the detection device comprising:

one or more heating sections that heat the mixed fluid;

a plurality of temperature detection units that detect the temperature of the heated mixed fluid;

a flow rate calculation unit configured to include at least a part of the heating unit and the plurality of temperature detection units, and to calculate a flow rate of the mixed fluid using an output from at least a part of the plurality of temperature detection units;

a correspondence relation storage unit that stores a correspondence relation between an output from the temperature detection unit and a mixing ratio of the substance in the mixed fluid at a predetermined flow rate;

a mixing ratio calculation section that calculates a mixing ratio of the substances in the mixed fluid based on the output from the temperature detection section and the correspondence relationship.

2. The detection apparatus of claim 1,

the mixing ratio calculation section calculates the mixing ratio of the substances in the mixed fluid based on the output from the temperature detection section constituting the flow rate calculation section and the correspondence relationship.

3. The detection apparatus of claim 1,

calculating a physical parameter of the mixed fluid using an output from the temperature detection units that are not included in the flow rate calculation unit and are arranged in a direction different from a flow direction of the mixed fluid,

the mixing ratio calculation section calculates the mixing ratio of the substances in the mixed fluid based on the output from the temperature detection section used in the calculation of the physical parameter and the correspondence relationship.

4. The detection apparatus of claim 3,

the flow rate correction unit corrects the flow rate of the mixed fluid based on an output from the temperature detection unit used for calculating the physical parameter.

5. The detecting device according to any one of claims 1 to 4,

the different species are oxygen and nitrogen.

6. The detecting device according to any one of claims 1 to 5,

the respiration detecting unit is also provided.

7. The detection apparatus of claim 6,

the breath detection unit includes a pressure detection device that detects a pressure of the mixed fluid.

8. The detection apparatus of claim 6,

the respiration detection means includes a flow rate fluctuation calculation unit that calculates a fluctuation in the flow rate of the mixed fluid based on the flow rate of the mixed fluid calculated by the flow rate calculation unit.

Technical Field

The present invention relates to a detection device.

Background

For example, in an oxygen concentrator, a mixed gas of oxygen and nitrogen flows through a flow path in the concentrator. Further, when the oxygen concentrator deteriorates with time, the proportion of oxygen in the mixed gas decreases and the proportion of nitrogen increases. That is, if the flow rate of the mixed gas and the concentration of oxygen contained in the mixed gas can be detected, the failure of the oxygen concentrator can be known. Not only the above example, but also the flow rate of the mixed fluid flowing through the flow path and the concentration of the substance contained in the mixed fluid need to be detected. Patent document 1 discloses an invention relating to a thermal flow sensor.

Disclosure of Invention

An aspect of the present invention is made in view of the above circumstances, and an object thereof is to provide a technique for obtaining a flow rate of a mixed fluid and a concentration of a substance contained in the mixed fluid by one detection device, thereby saving costs required for detection.

In order to solve the above problem, the present invention adopts the following configuration.

That is, a detection device according to an aspect of the present invention is a detection device that detects a characteristic of a mixed fluid containing different types of substances having a difference in thermal properties within a predetermined range, the detection device including: one or more heating sections that heat the mixed fluid; a plurality of temperature detection units that detect the temperature of the heated mixed fluid; a flow rate calculation unit configured to include at least a part of the heating unit and the plurality of temperature detection units, and to calculate a flow rate of the mixed fluid using an output from at least a part of the plurality of temperature detection units; a correspondence relation storage unit that stores a correspondence relation between an output from the temperature detection unit and a mixing ratio of the substance in the mixed fluid at a predetermined flow rate; a mixing ratio calculation section that calculates a mixing ratio of the substances in the mixed fluid based on the output from the temperature detection section and the correspondence relationship.

The predetermined range is a range in which the thermal properties of the entire mixed fluid are substantially equal even when the mixing ratio is changed, and is, for example, a range in which the thermal resistivity of oxygen (49192[ s/m ])²]) And thermal resistivity of nitrogen (49575[ s/m ]²]) The range of convergence of the difference. The predetermined range is, for example, a difference in thermal properties of at least one of thermal resistivity, thermal resistance, thermal conductivity, and thermal diffusivity, and may be a range of 1% or less with respect to the maximum value of the thermal properties of the substance contained in the mixed fluid.

In the above configuration, when the mixed fluid flows, the mixed fluid is heated by the heating unit, whereby the flow rate of the mixed fluid can be calculated. Further, the mixing ratio corresponding to the output from the temperature detection section can be calculated using the correspondence stored in the correspondence storage section. Therefore, the concentration of the substance contained in the mixed fluid can be calculated from the calculated flow rate and the mixing ratio.

In the detection device according to the one aspect, the mixing ratio calculation section may calculate the mixing ratio of the substances in the mixed fluid based on the output from the temperature detection section constituting the flow rate calculation section and the correspondence relationship. According to this configuration, the flow rate of the mixed fluid and the concentration of the substance contained in the mixed fluid can be obtained by one detection device, and cost can be saved.

In the detection device according to the one aspect, the physical parameter of the mixed fluid may be calculated using outputs from the temperature detection units that are provided in a direction different from the flow direction of the mixed fluid and that are not included in the flow rate calculation unit, among the plurality of temperature detection units, and the mixing ratio calculation unit may calculate the mixing ratio of the substances in the mixed fluid based on the outputs from the temperature detection units used in the calculation of the physical parameter and the correspondence relationship.

According to this configuration, the output from the temperature detection units arranged in a direction different from the flow direction of the mixed fluid is not affected by the flow rate. Therefore, the physical parameter and the mixture ratio can be calculated independently of the flow rate. That is, the physical parameters and the mixing ratio can be easily calculated with high accuracy.

In the detection device according to the aspect, the flow rate correction unit may be configured to correct the flow rate of the mixed fluid based on an output from the temperature detection unit used for calculating the physical parameter.

According to this configuration, the flow rate can be corrected based on the physical parameter, and the flow rate close to the flow rate of the mixed fluid flowing in reality can be calculated.

In the detection device of the aspect, the different species may also be oxygen and nitrogen. With this configuration, the flow rate of the mixed fluid and the mixing ratio of oxygen and nitrogen contained in the mixed fluid can be calculated. It is needless to say that the concentration may be calculated from the derived flow rate and the derived mixing ratio. Further, in the case where the mixing ratio calculation section calculates the mixing ratio of the mixed fluid using the output from the temperature detection section constituting the flow rate calculation section, the oxygen concentration in the mixed fluid can be detected by one device.

The detection device according to the one aspect may further include a respiration detection unit. According to this configuration, it is possible to detect not only the flow rate of the mixed fluid and the concentration of the substance contained in the mixed fluid, but also respiration.

In the detection device according to the aspect, the breath detection unit may include a pressure detection device that detects a pressure of the mixed fluid. According to this configuration, it is possible to detect not only the flow rate of the mixed fluid and the concentration of the substance contained in the mixed fluid, but also the pressure of the mixed fluid and perform respiration detection.

In the detection device according to the aspect of the invention, the respiration detection means may include a flow rate fluctuation calculation unit that calculates a fluctuation in the flow rate of the mixed fluid based on the flow rate of the mixed fluid calculated by the flow rate calculation unit.

According to this configuration, the fluctuation of the flow rate of the mixed fluid can be calculated from the calculated flow rate of the mixed fluid, and the respiration detection can be performed. Therefore, it is economical to perform the breath detection without increasing the number of parts.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a technique for obtaining the flow rate of the mixed fluid and the concentration of the substance contained in the mixed fluid by one detection device, thereby saving the cost required for detection.

Drawings

Fig. 1 schematically illustrates an example of a detection device according to an embodiment.

Fig. 2 schematically illustrates an example of an enlarged view of the detection element.

Fig. 3 schematically illustrates an example of a cross section of the detection device of the embodiment.

Fig. 4 schematically illustrates a schematic view of the detection device according to the embodiment when the detection device is provided in a flow tube member.

Fig. 5A schematically illustrates an example of the temperature distribution when the micro-heater is activated in a state where gas does not flow through the flow tube part.

Fig. 5B schematically illustrates an example of the temperature distribution when the micro-heater is activated in a state where the gas flows through the flow tube part.

Fig. 6 schematically illustrates an example of a block diagram showing a functional configuration of the detection device according to the embodiment.

Fig. 7 schematically illustrates an example of the correspondence table.

Fig. 8 schematically illustrates an example of an experimental result in which the mixed gas having the changed mixture ratio is made to flow through the flow tube member and the output of the thermoelectric element on one side is plotted in a graph.

Fig. 9 schematically illustrates an example of a flowchart showing a processing procedure of the detection apparatus of the embodiment.

Fig. 10 schematically illustrates an example of a detection device further including a pressure detection device for detecting the pressure of the mixed fluid.

Fig. 11 schematically illustrates an example of a perspective view of the detection device and the flow tube member in a case where the thermal diffusivity of the mixed gas is taken into consideration when calculating the flow rate.

Fig. 12 schematically illustrates an example of a block diagram showing a functional configuration of the detection device.

Fig. 13 schematically illustrates an example of a relationship between the detection element and the flow of the mixed gas flow.

Fig. 14 schematically illustrates an example in which the flow tube member having two flow path portions, i.e., a main flow path portion and a sub flow path portion, has a detection device.

Fig. 15 schematically illustrates an example of a partially enlarged view of the secondary flow path portion.

Fig. 16 schematically illustrates an example of a cross-sectional view when the detection device is provided in the flow tube member.

Detailed Description

Hereinafter, an embodiment (hereinafter referred to as "the present embodiment") according to one aspect of the present invention will be described with reference to the drawings. However, the present embodiment described below is merely an example of the present invention in all aspects. Of course, various modifications and alterations can be made without departing from the scope of the invention. That is, in the embodiments of the present invention, the specific configurations corresponding to the embodiments can be adopted as appropriate.

Application example § 1

An example of a scenario to which the present invention is applied will be described with reference to fig. 1. Fig. 1 schematically illustrates an example of the detection apparatus 100 of the present embodiment. The detection device 100 includes a detection element 1, a control unit 2, and a circuit board 3 on which the detection element 1 and the control unit 2 are mounted. The mixed fluid flows in the flow tube part 4. Then, one flow path section 5 is formed at the upper part of the flow tube member 4. The detection device 100 is fixed to the flow tube member 4 such that the detection element 1 is positioned in the flow path section 5. The detection element 1 includes a micro heater and a thermoelectric element in the vicinity of the micro heater. The detection element 1 is a so-called thermal flow sensor.

Here, the flow rate of the mixed fluid is calculated as follows. When the mixed fluid flows through the flow tube member 4, if the micro-heater is activated, the vicinity of the micro-heater is heated. Then, a signal regarding the temperature in the vicinity of the micro-heater is output from the thermoelectric element. When the mixed fluid flows, if the micro-heater is used for heating, the heat generated by the micro-heater is biased to be diffused by the influence of the mixed fluid flow. This biased thermal diffusion is measured by a thermoelectric element, and the flow rate of the mixed fluid is calculated.

The concentration of the substance contained in the mixed fluid is calculated as follows. First, the correspondence between the output from one thermoelectric element and the mixing ratio of the mixed fluid at a predetermined flow rate is determined in advance. Then, the mixing ratio is calculated from the flow rate calculated from the difference between the output value from one of the thermoelectric elements and the output value from 2 thermoelectric elements, and the correspondence relationship described above, when the fluid to be measured flows through the flow tube member 4. Then, the concentration of the substance contained in the mixed fluid is calculated based on the mixing ratio and the calculated flow rate.

As described above, in the present embodiment, the flow rate of the mixed fluid and the concentration of the substance contained in the mixed fluid can be detected by one detection device 100. Therefore, the number of parts can be reduced, and the cost required for detection can be saved.

Construction example 2

[ hardware constitution ]

Next, an example of the detection device of the present embodiment will be described. The detection device 100 of the present embodiment detects, for example, the flow rate and the oxygen concentration of a mixed gas of oxygen and nitrogen flowing through the flow tube member 4 in an oxygen concentrator used by a patient suffering from a respiratory disease. As shown in fig. 1, the detection device 100 includes a detection element 1, a control section 2, and a circuit board 3 on which the detection element 1 and the control section 2 are mounted.

Fig. 2 schematically illustrates an example of an enlarged view of the detection element 1 of the present embodiment. The detection element 1 includes a micro-heater 6 and thermoelectric elements 7A and 7B. Here, the micro-heater 6 is an example of the "heating section" of the present invention. The thermoelectric elements 7A and 7B are an example of the "temperature detection unit" of the present invention. The micro-heater 6 is a resistor made of, for example, polysilicon, and is provided in the center of the detection element 1. The thermoelectric elements 7A and 7B are disposed on both sides of the micro-heater 6 so as to sandwich the micro-heater 6.

Fig. 3 schematically illustrates an example of a cross section of the detection apparatus 100. Insulating films 7 are formed on the upper and lower sides of the micro-heater 6 and the thermoelectric elements 7A and 7B. Further, the circuit board 3 below the thermoelectric elements 7A and 7B is provided with a cavity 9. Fig. 4 schematically illustrates a schematic view of the detection device 100 fixed to the flow tube member 4. The detection device 100 is provided such that the detection element 1 is fitted into the central portion of the flow path portion 5. The detection device 100 is provided such that the thermoelectric element 7A is on the upstream side in the flow direction of the mixed gas and the thermoelectric element 7B is on the downstream side.

[ principle of flow measurement ]

Next, the principle of flow rate detection using the detection element 1 will be explained. Fig. 5A schematically illustrates an example of the temperature distribution when the micro-heater 6 is activated in a state where the gas does not flow through the flow tube member 4. On the other hand, fig. 5B schematically illustrates an example of the temperature distribution when the micro-heater 6 is activated in a state where the gas flows through the flow tube member 4. In the case where the gas does not flow through the flow tube member 4, the heat from the micro-heater 6 is symmetrically diffused centering on the micro-heater 6. Therefore, no difference is generated in the outputs from the thermoelectric elements 7A and 7B. On the other hand, when the gas flows through the flow tube member 4, the heat from the micro-heater 6 is influenced by the gas flow and is not diffused symmetrically about the micro-heater 6 but is further diffused toward the thermoelectric element 7B side in the downstream direction. Therefore, a difference occurs in the outputs from the thermoelectric elements 7A and 7B. Further, the larger the flow rate of the gas, the larger the difference in output. The relationship between the flow rate of the gas and the difference between the outputs from the thermoelectric elements 7A and 7B is expressed by the following expression (1)

Here, Δ V represents the flow rate of the fluid, T_ARepresents an output value, T, from the thermoelectric element 7A_BRepresents the output value measured by the pyroelectric element 7B. In addition, V_fIs the flow rate of the fluid, and a and b are constants. In the present embodiment, the flow rate is calculated according to the above principle.

[ functional constitution ]

Fig. 6 schematically illustrates an example of a block diagram showing a functional configuration of the detection apparatus 100. Here, the control unit 2 includes a flow rate calculation unit 10, and the flow rate calculation unit 10 receives signals output from the thermoelectric elements 7A and 7B, and calculates the flow rate of the fluid based on the received signals. The flow rate calculation unit 10 is an example of the "flow rate calculation unit" of the present invention. Equation (1) is used to calculate the flow rate of the mixed gas from the outputs of the thermoelectric elements 7A and 7B. As shown in equation (1), the control unit 2 obtains the flow rate of the mixed gas based on the difference in output from the thermoelectric elements 7A and 7B.

The detection device 100 further includes a correspondence relation storage unit 12, and the correspondence relation storage unit 12 stores a correspondence relation table 11 in which a correspondence relation between an output from the thermoelectric element 7A and a mixture ratio of the mixed gas at a predetermined flow rate is recorded. Fig. 7 schematically illustrates an example of the correspondence table 11. Here, the correspondence table 11 is an example of "correspondence" of the present invention. The correspondence relation storage unit 12 is an example of the "correspondence relation storage unit" of the present invention. Then, the control unit 2 includes a mixture ratio calculation unit 13, and the mixture ratio calculation unit 13 receives the information of the correspondence table 11 stored in the correspondence storage unit 12, the flow rate information calculated in the flow rate calculation unit 10, and the information on the output from the thermoelectric element 7A, and calculates the mixture ratio of the mixture gas. The mixing ratio calculation section 13 is an example of the "mixing ratio calculation section" of the present invention.

The correspondence table 11 is prepared in advance for each flow rate. The correspondence table 11 is created by flowing a mixed gas of oxygen and nitrogen through the flow tube unit 4 while changing the mixing ratio, and plotting the relationship between the mixing ratio and the output from the thermoelectric element 7A. The flow rate is calculated by substituting the difference between the outputs of the thermoelectric elements 7A and 7B into formula (1).

Fig. 8 schematically illustrates an example of the experimental result in which the mixed gas having the changed mixture ratio is made to flow through the flow tube member 4, and the output of the thermoelectric element on one side (for example, the thermoelectric element 7A) is plotted. As shown in fig. 8, it was confirmed that the output of the thermoelectric element on one side had a correlation with the oxygen concentration. That is, if the output of the thermoelectric element on one side can be obtained, the mixing ratio is uniquely determined.

However, in the case of a general mixed gas, when the mixing ratio of the mixed gas and the mixing ratio of the measurement target gas in the case of making the correspondence table 11 are different, the difference between the outputs from the thermoelectric elements 7A and 7B and the outputs from the thermoelectric elements 7A and 7B is caused even if the mixed gas and the measurement target gas are made to flow at the same flow rate in the case of making the correspondence table 11 and the measurement target gas, and the calculated flow rates of the two calculated from the difference are also caused to be different. That is, in order to obtain the mixing ratio of the measurement target gas, a highly reliable mixing ratio cannot be obtained even if the correspondence table 11 is used.

However, in the mixed gas of the present embodiment, the mixed gas is used as the mixed gasThe thermal resistivity of one example of the thermal properties of the oxygen molecules and the nitrogen molecules contained in (A) is 49192[ s/m ] respectively²]And 49575[ s/m ]²]. In the case of such thermal resistivity, even when the mixture ratio of the mixed gas and the mixture ratio of the gas to be measured are different in the correspondence table 11, when the mixed gas and the gas to be measured are made to flow at the same flow rate in the correspondence table 11 and the gas to be measured, there is no difference in the difference between the outputs from the thermoelectric elements 7A and 7B and the outputs from the thermoelectric elements 7A and 7B, and there is no difference in the calculated flow rates of the two calculated from the difference. That is, even when the mixing ratio at the time of producing the correspondence table 11 is different from the mixing ratio of the measurement target gas, the correspondence table 11 can be used to calculate the mixing ratio of the measurement target fluid.

Action example 3

Next, an operation example of the detection device 100 will be described with reference to fig. 9. Fig. 9 schematically illustrates an example of a flowchart showing a processing procedure of the detection apparatus 100. The processing procedure described below is an example, and each process may be changed as much as possible. In addition, regarding the processing order described below, the steps may be omitted, replaced, and added as appropriate according to the embodiment.

(step S101)

First, using the oxygen concentrator, the micro-heater 6 is activated when the mixed gas of oxygen and nitrogen flows into the flow tube part 4. After the micro heater 6 is activated, the vicinity of the micro heater 6 is heated.

(step S102)

In step S102, an output corresponding to the temperature near the thermoelectric elements is output from the thermoelectric elements 7A and 7B. The signals relating to the temperatures output from the thermoelectric elements 7A and 7B are sent to the flow rate calculating unit 10. When the micro heater 6 is used to heat the vicinity of the micro heater 6, the output results from the thermoelectric elements 7A and 7B differ due to the influence of the fluid flowing in the flow tube member 4.

(step S103)

In step S103, the flow rate calculation unit 10 receives signals regarding the temperatures output from the thermoelectric elements 7A and 7B, and calculates the flow rate of the mixed gas flowing through the flow pipe member 4 using equation (1). From the above steps, the flow rate of the mixed gas flowing through the flow tube member 4 is calculated. In the following procedure, the mixing ratio calculation unit 13 calculates the oxygen concentration of the mixed gas using the output from the thermoelectric element 7A, the calculated flow rate of the mixed gas, and the correspondence table 11 stored in the correspondence storage unit 12.

(step S104)

In step S104, a mixing ratio corresponding to the calculated flow rate and the output value from the thermoelectric element 7A is selected from the correspondence table 11. Here, when the mixture ratio is selected from the correspondence table 11, the mixture ratio corresponding to the 2 values before and after the closest of the calculated flow rate and the output value from the thermoelectric element 7A is selected from the correspondence table 11, and a value obtained by proportionally distributing these 2 mixture ratios may be used as the mixture ratio of the mixed gas.

(step S105)

As described above, the mixing ratio is determined using the output value from the thermoelectric element 7A and the flow rate calculated from the difference between the thermoelectric elements 7A and 7B and the correspondence table 11. Then, the oxygen concentration is calculated from the calculated flow rate and the mixture ratio. By performing the above steps, the flow rate and the oxygen concentration of the mixed gas flowing through the flow pipe member 4 can be obtained.

In the present embodiment, the mixing ratio of the mixed gas is calculated based on the output from the thermoelectric element 7A as shown in the correspondence table 11 and the like, but the mixing ratio may be performed based on the output from the thermoelectric element 7B. Further, the outputs of the thermoelectric elements 7A and 7B may be combined to calculate the mixing ratio. In the case of combining the outputs of the thermoelectric elements 7A and 7B, more accurate mixing ratio calculation can be performed from the viewpoint of the amount of information. The correspondence table 11 is prepared in advance as appropriate.

[ Effect, Effect ]

As described above, in the present embodiment, the flow rate of the mixed gas of oxygen and nitrogen flowing through the flow tube member 4 of the oxygen concentrator can be calculated by the detection device 100. Further, based on the calculated flow rate and the output from the thermoelectric element 7A, the oxygen concentration in the mixed gas can be determined. The oxygen concentrator increases the concentration of nitrogen contained in the mixed gas due to the deterioration with time, but if the detection device 100 of the present embodiment is used, the deterioration with time can be detected. The calculation of the flow rate and the oxygen concentration is performed by one detection device 100. Therefore, the cost required for detection can be reduced.

Modification example 4

The embodiments of the present invention have been described in detail, but the above description is merely illustrative of the present invention in all aspects. Of course, various modifications and alterations can be made without departing from the scope of the invention. For example, the following modifications may be made. Hereinafter, the same reference numerals are used for the same components as those of the above embodiment, and the description thereof will not be repeated. The following modifications can be combined as appropriate.

＜4.1＞

For example, fig. 10 schematically illustrates an example of a detection device 102 further including a pressure detection device 101 that detects the pressure of the mixed fluid. Here, the pressure detection device 101 is an example of the "breathing detection unit" of the present invention. The detection device 102 can be used, for example, to detect the concentration of oxygen contained in the mixed gas flowing through the flow tube in the oxygen concentrator 500 and the pressure of the mixed gas flowing through the flow tube. The oxygen concentrator 500 is used by a patient suffering from a respiratory disease, for example. The oxygen concentrator 500 includes a compressor 501 that compresses, for example, air taken in from the outside of the system; a sieve bed (シーブベッド)502 that pressurizes or depressurizes the air compressed in the compressor 501, thereby generating oxygen of high concentration. The oxygen concentrator 500 includes an oxygen tank 503 for storing the generated high-concentration oxygen, and a flow rate control solenoid valve 504 for controlling the flow rate of a mixed gas containing the high-concentration oxygen delivered from the oxygen tank 503 to the patient.

Here, the circuit board 3 on which the detection element 1 and the control unit 2 are mounted is provided on the flow tube member 4A in the oxygen tank 503 of the oxygen concentrator 500. The detection device 102 detects the oxygen flow rate and the oxygen concentration in the flow tube member 4A of the oxygen concentrator 500. The pressure detection device 101 is provided on the way of the flow tube member 4A extending from the flow rate control solenoid valve 504 to the mouth of the patient. Then, the pressure of the mixed gas of oxygen and nitrogen passing through the flow tube member 4A is detected. Therefore, for example, when a patient suffering from a respiratory disease inhales oxygen from an oxygen concentrator, it is possible to judge whether the patient breathes normally, the intensity of inhalation of the patient, and the like.

In the above modification, the detection device 102 includes the pressure detection device 101 and detects the breathing of the patient by the pressure detection device 101, but may include a flow rate fluctuation calculation unit that calculates the flow rate fluctuation of the mixed fluid based on the flow rate of the mixed fluid calculated by the flow rate calculation unit 10 instead of the pressure detection device 101. Here, the flow rate fluctuation calculation unit is an example of the "breathing detection unit" of the present invention. In the detection device 102, the respiration can be detected from the fluctuation of the flow rate calculated by the flow rate fluctuation calculation unit. In addition, since the breath detection can be performed without increasing the number of components, it is economical.

＜4.2＞

In addition, when the flow rate of the mixed gas is calculated in the flow rate calculating unit 10, thermal properties such as thermal diffusivity of the mixed gas may be considered. According to such a calculation method, a flow rate close to the actual mixed gas flow rate can be calculated. Fig. 11 schematically illustrates an example of a perspective view of the detection device 100A and the flow tube member 4B in a case where the thermal diffusivity of the mixed gas is taken into consideration when calculating the flow rate. As shown in fig. 11, the detection apparatus 100A includes a detection element 14 for detecting the thermal diffusivity of the mixed gas, in addition to the detection element 1 and the control section 2 for measuring the flow rate and the oxygen concentration of the mixed gas. Although not shown, the flow pipe member 4B has a flow path along the flow of the mixed gas like the flow path portion 5 of the flow pipe member 4, and the detection element 1 and the detection element 14 are arranged in the one flow path in the direction blocking the flow of the gas. The detection element 14 is a thermal flow sensor of the same type as the detection element 1, and includes a micro heater 6A and thermoelectric elements 7C and 7D as the detection element 1.

Fig. 12 schematically illustrates an example of a block diagram showing a functional configuration of the detection apparatus 100A. The control unit 2A of the detection device 100A includes a flow rate correction unit 15 in addition to the configuration of the control unit 2, and the flow rate correction unit 15 receives the detection results from the thermoelectric elements 7C and 7D of the detection element 14 and corrects the flow rate of the mixed fluid. The flow rate correction unit 15 is an example of the "flow rate correction unit" of the present invention. Further, the mixture ratio calculation section 13 calculates the mixture ratio based on the output from the thermoelectric element 7C and the correspondence table 11 stored in the correspondence storage section 12. Then, the oxygen concentration of the mixed gas is calculated from the calculated mixture ratio and the flow rate corrected by the flow rate correction unit 15. Here, the correspondence table 11 shows the relationship between the mixing ratio and the output from the thermoelectric element 7C, in which the mixed gas of oxygen and nitrogen is caused to flow into the flow tube member 4B while the mixing ratio is changed.

Fig. 13 schematically illustrates an example of the relationship between the detection element 14 and the flow of the mixed gas. The detection element 14 is provided in a flow path provided in the flow tube unit 4B such that the micro-heater 6A and the thermoelectric elements 7C and 7D are arranged in a direction blocking the flow of the mixed gas. The thermal diffusivity of the mixed gas can be calculated from the outputs from the thermoelectric elements 7C and 7D by heating the space in the vicinity by the micro-heater 6A. In addition, as shown in fig. 13, when the micro-heater 6A and the thermoelectric elements 7C and 7D are arranged in a direction of blocking the flow of the mixed gas, the heat from the micro-heater 6A is diffused symmetrically in both directions of the thermoelectric elements 7C and 7D with the micro-heater 6A as the center. In addition, the diffusion to the thermoelectric elements 7C and 7D is independent of the flow rate. Therefore, the detection element 14 can calculate the thermal diffusivity independent of the flow rate based on the outputs from the thermoelectric elements 7C and 7D before and after heating. Further, the calculated thermal diffusivities of the two are averaged, and a thermal diffusivity in which the output variation from the thermoelectric element is reduced can be calculated.

Then, by multiplying the value relating to the thermal diffusivity calculated as described above by the flow rate of the mixed gas calculated by the flow rate calculation unit 10, the flow rate calculated by the flow rate calculation unit 10 can be corrected to a flow rate close to the actual flow rate of the mixed gas. Therefore, a value close to the flow rate of the mixed fluid flowing in reality can be calculated.

In the present modification, the mixing ratio can be calculated from the output from the thermoelectric element 7C and the correspondence table 11. Then, from the calculated mixture ratio and flow rate, the oxygen concentration can be calculated. Here, since the micro-heater 6A and the thermoelectric element 7C are arranged in a direction blocking the flow of the mixed gas, the output of the thermoelectric element 7C does not depend on the flow rate. That is, the correspondence table 11 does not need to be created for each flow rate, and flow rate information is not needed when calculating the mixing ratio. That is, since the mixing ratio that is not affected by the flow rate can be calculated, the calculated mixing ratio is a value with high accuracy.

In the present modification, the mixing ratio is calculated using the output from the thermoelectric element 7C, but the mixing ratio may be calculated using the output from the thermoelectric element 7D. At this time, a correspondence table 11 of the output from the thermoelectric element 7D and the mixing ratio is prepared in advance. Further, the mixing ratio calculation section 13 receives an output from the thermoelectric element 7D. The mixing ratio may be calculated using an average value of outputs from the thermoelectric element 7C and the thermoelectric element 7D. At this time, correspondence table 11 of the average output values and the mixture ratios from thermoelectric element 7C and thermoelectric element 7D is prepared in advance. At this time, mixing ratio calculation unit 13 receives outputs from thermoelectric element 7C and thermoelectric element 7D, averages these values, and uses them for calculating the mixing ratio. As described above, when the mixing ratio is calculated using the average value of the outputs of the thermoelectric element 7C and the thermoelectric element 7D, the influence of the deviation of the outputs from the thermoelectric elements is reduced, so that the accuracy of the calculated mixing ratio is improved.

＜4.3＞

In the modification < 4.2 >, the detection element 1 and the detection element 14 are provided in a flow path of the flow tube member 4B, but the detection element 1 and the detection element 14 may be provided in different flow paths. Fig. 14 schematically illustrates an example in which the detection device 100B is provided in the flow tube member 4C including two flow path sections, i.e., the main flow path section 16 and the sub flow path section 17.

Here, the detection device 100B includes a disk-shaped circuit board 19, a cover 19 covering an outer surface of the circuit board 19, and a sealing member 20 bonding the circuit board 19 and the flow tube member 4C. The flow tube member 4C includes two flow path portions, i.e., a main flow path portion 16 and a sub flow path portion 17. The main flow path portion 16 is a tubular member. The sub-channel 17 is located on the side of the main channel 16, and forms a sub-channel therein. Fig. 15 schematically illustrates an example of a partially enlarged view of the secondary flow path portion 17. The main flow path portion 16 and the sub flow path portion 17 communicate with each other via an inflow circuit 21 and an outflow circuit 22. The sub flow path portion 17 includes: a flow rate detection flow path 23 for detecting the flow rate of the mixed gas branches from the inflow flow path 21, and a physical parameter detection flow path 24 for detecting the thermal diffusivity of the mixed gas branches from the inflow flow path 21 in the same manner. The flow rate detection channel 23 and the physical parameter detection channel 24 branching from the inflow channel 21 merge into the outflow channel 22.

The flow rate detection flow channel 23 is a substantially コ -shaped flow channel. The flow rate detection flow path 23 includes a detection element arrangement portion 25A, and the detection element arrangement portion 25A is provided with the detection element 1 for detecting the flow rate of the mixed gas in the middle of the longitudinal direction (the direction parallel to the main flow path portion 16).

The physical parameter detection channel 24 is also a channel in a substantially コ shape, similar to the flow rate detection channel 23. The physical parameter detection flow path 24 has a detection element arrangement portion 25B in which the detection element 14 for measuring the thermal diffusivity of the mixed gas is provided midway in the longitudinal direction (the direction parallel to the main flow path portion 16). Here, the micro-heater and the pyroelectric element of the detection element 14 are arranged in a direction of blocking the flow of the mixed gas, although not shown.

In the present modification, the length of the main channel portion 16 in the axial direction is about 50mm, the diameter of the inner peripheral surface (the inner diameter of the main channel portion 16) is about 20mm, and the outer diameter of the main channel portion 16 is about 24 mm.

The flow tube member 4C of the detection apparatus 100B is fixed as follows. First, the sub-channel 17 and the circuit board 19 are bonded to each other by the sealing material 20. Then, the surface of the circuit substrate 19 is covered with the cover 19. By such a fixing method, airtightness of the inside of the sub-flow path portion 17 is ensured. Therefore, the outside air of the flow tube member 4C does not intrude into the sub-flow path portion 17, and does not affect the detection of the flow rate or the physical parameter.

Fig. 16 schematically illustrates an example of a cross-sectional view when the detection device 100B is provided in the flow tube member 4C. The flow tube member 4C has a resistor 26 in the vicinity of the secondary flow path portion 17. When the mixed gas flows into the main flow path portion 16, a part of the mixed gas is blocked by the resistor 26 and flows into the sub flow path portion 17 through the inflow flow path 21. Then, the mixed gas having the same conditions such as temperature and concentration flows into the flow rate detection circuit 23 and the physical parameter detection circuit 24 branched from the secondary flow path portion 17. Therefore, the thermal diffusivity of the fluid having conditions such as temperature and concentration equal to those of the mixed gas detected from the detection element 1 can be calculated using the detection element 14. Therefore, the flow rate of the mixed gas can be corrected according to the thermal diffusivity of the fluid having the same conditions such as temperature and concentration, and the measurement accuracy of the detection device 100B can be improved.

In the detection device 100B, the flow rates of the gases branched to the flow rate detection flow path 23 and the physical parameter detection flow path 24 can be individually controlled by adjusting the widths of the respective flow paths. Therefore, the flow rate of the gas flowing through the flow rate detection circuit 23 is controlled in accordance with the detection range of the detection element 1, and the flow rate of the gas flowing through the physical parameter detection circuit 24 is controlled in accordance with the detection range of the detection element 14.

Therefore, the detection device 100B can detect the flow rate and the characteristics of the gas at the optimum flow rate corresponding to the detection range specific to each detection element. Therefore, the detection elements 1, 14 can measure the flow rate and the characteristics of the gas with high accuracy.

It goes without saying that the oxygen concentration may be calculated from the obtained flow rate, as in the modification < 4.2 >.

The detection device 100A and the detection device 100B use the thermal diffusivity for correcting the flow rate, but the thermal diffusivity is not limited thereto, and a physical parameter indicating the thermal property of the mixed gas may be measured and the flow rate may be corrected using the physical parameter.

In the above embodiment, the correspondence table 11 depicts the relationship between the output from the thermoelectric element and the mixture ratio of the mixed gas, but the relationship between the physical quantity related to the output from the thermoelectric element and the mixed gas may be plotted and used for the mixture ratio calculation. In the detection devices 100A and 100B, the substances contained in the mixed gas are oxygen and nitrogen, but the substances contained in the mixed gas are not limited to oxygen and nitrogen, and may not be close to thermal properties. Since the mixture ratio calculation unit 13 is not affected by the flow rate, if it is a self-explanatory mixture gas, the mixture ratio can be estimated using the correspondence table independent of the flow rate, and the flow rate can be corrected based on the estimation result. The detection target is not limited to a gas, and may be a fluid substance such as a liquid.

In the detection devices 100A and 100B, the flow rate is corrected by the flow rate correction unit 15, but the flow rate may not be corrected.

The embodiments and the modifications disclosed above may be combined separately.

In order to make it possible to compare the constituent elements of the present invention with those of the embodiments, the constituent elements of the present invention are described below in the form of reference numerals of the drawings.

< invention 1 >)

A detection device (100) for detecting a characteristic of a mixed fluid containing different kinds of substances having a difference in thermal properties within a predetermined range, the detection device comprising

One or more heating portions (6) that heat the mixed fluid;

a plurality of temperature detection units (7A, 7B, 7C, 7D) that detect the temperature of the heated mixed fluid;

a flow rate calculation unit (10) that includes the heating unit (6) and at least a part of the plurality of temperature detection units (7A, 7B, 7C, 7D), and that calculates a flow rate of the mixed fluid using outputs from at least a part of the plurality of temperature detection units (7A, 7B, 7C, 7D);

a correspondence relation storage unit 12 that stores a correspondence relation between outputs from the temperature detection units (7A, 7B, 7C, 7D) and a mixing ratio of the substances in the mixed fluid at a predetermined flow rate;

and a mixing ratio calculation unit (13) that calculates the mixing ratio of the substances in the mixed fluid based on the output from the temperature detection units (7A, 7B, 7C, 7D) and the correspondence relationship.

< invention 2 >

In the detection device (100) according to claim 1, the mixing ratio calculation unit (13) calculates the mixing ratio of the substances in the mixed fluid based on the outputs from the temperature detection units (7A, 7B) constituting the flow rate calculation unit (10) and the correspondence relationship.

< invention 3 >)

In the detection devices (100A, 100B) according to invention 1, the physical parameter of the mixed fluid is calculated using the outputs of the temperature detection units (7C, 7D) that do not constitute the flow rate calculation unit (10) and are arranged in a direction different from the flow direction of the mixed fluid, among the plurality of temperature detection units (7A, 7B, 7C, 7D),

the mixing ratio calculation unit (13) calculates the mixing ratio of the substances in the mixed fluid based on the outputs from the temperature detection units (7C, 7D) used in the calculation of the physical parameter and the correspondence relationship.

< invention 4 >

The detection devices (100A, 100B) according to claim 3 further comprise a flow rate correction unit (15) that corrects the flow rate of the mixed fluid based on an output from the temperature detection units (7C, 7D) used for calculating the physical parameter.

< invention 5 >

In the detection device (100, 100A, 100B) according to any one of inventions 1 to 4, the different species are oxygen and nitrogen.

< invention 6 >

The detection device (102) according to any one of claims 1 to 5, further comprising a respiration detection means.

< invention 7 >

In the detection device (102) according to invention 6, the breath detection unit includes a pressure detection device (101) for detecting a pressure of the mixed fluid.

< invention 8 >

In the detection device (102) according to claim 6, the respiration detection means includes a flow rate fluctuation calculation unit that calculates a flow rate fluctuation of the mixed fluid based on the flow rate of the mixed fluid calculated by the flow rate calculation unit (10).

Description of the symbols

1. 14: detection element

2. 2A: control unit

3. 18: circuit board

4. 4A, 4B, 4C: flow tube component

5: flow path part

6. 6A: micro heater

7. 7A, 7B, 7C, 7D: thermoelectric element

8: insulating film

9: hollow cavity

10: flow rate calculating part

11: corresponding relation table

12: correspondence relation storage unit

13: mixing ratio calculation section

15: flow correction unit

16: main flow path part

17: sub flow path part

19: cover

20: sealing element

21: inflow flow path

22: outflow channel

23: flow path for flow rate detection

24: flow path for detecting physical parameters

25A: detecting element arranging part

25B: detecting element arranging part

26: resistor body

100. 100A, 100B, 102: detection device

101: pressure detection device

500: oxygen concentrator

501: compressor with a compressor housing having a plurality of compressor blades

502: sieve bed

503: oxygen tank

504: flow control solenoid valve