Valve device for monitoring and controlling pressure, flow and time for breath detection

Abstract

The present invention discloses a valve device for monitoring and controlling pressure, flow and time for breath detection, comprising: a supporting shell, a spring, a valve core and an orifice plate; the orifice plate is arranged at one end of the supporting shell; the valve core is arranged inside the supporting shell; the spring is sleeved on the valve core; the valve core is provided with a valve head at one end close to the orifice plate; a through hole corresponding to the valve head is provided on the orifice plate; the spring is made of semiconductor material. The present invention can directly calculate the flow rate through displacement changes, replace traditional pressure sensors and flow sensors, integrate the pressure, flow and time monitoring and control functions in breath detection, and has a compact and simplified overall design, reduces the dead space volume, reduces costs, and has higher reliability and stability.

Description

Technical Field

[0001] The present invention relates to the technical field of breath detection, and more specifically to a valve device for monitoring and regulating pressure, flow and time for breath detection. Background Art

[0002] Research has shown that there are many components in exhaled breath that can help people gain a deeper understanding of the metabolic process of a certain disease, and can be indicative of certain diseases, or even indicate the presence of pathogens of certain diseases. In research and clinical settings, examples of gases present in exhaled breath include nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide (H2S), hydrogen (H2), methane (CH4), carbon dioxide (CO2), oxygen (O2), and volatile organic compounds (VOCs).

[0003] However, in order to obtain reliable and repeatable measurement results, the exhaled air flow and pressure during sampling must be strictly controlled. For example, the technical standard for exhaled NO determination jointly formulated by the American Thoracic Society (ATS) and the European Respiratory Society (ERS) in 2005 requires that the subjects maintain a constant exhaled air flow of 50 mL / s during sampling at an exhaled air pressure of at least 5 cmH2O, exhale continuously for 10 seconds (adults) or 6 seconds (children), empty the physiological and instrumental dead space air in front, and only test and analyze the exhaled air after the NO concentration reaches a stable state.

[0004] At present, the prior art is usually equipped with a flow sensor, a pressure sensor and a solenoid valve for emptying and testing gas control. For example, the existing patent CN115728477A discloses a breath nitric oxide measuring device, which involves the realization of regulating and controlling multiple flow segments in a flow regulating device. The existing patent CN213147942U discloses an exhaled air flow regulating device, which involves an exhaled air flow regulating device, and can realize the regulation and control of multiple flow segments. The existing patent CN107961042A discloses an intelligent exhaled air sampling method and device, which involves an exhaled air flow regulating device. During exhalation, the airflow is fed back to the control unit through a sensor to control the flow control module to adjust the required flow. The above patent technologies only involve one or one or two technologies such as flow measurement or flow control, use a pressure sensor to convert the flow, monitor the results for flow control, and control the valve according to the emptying time. The pipeline is relatively complicated to implement, which increases the dead space volume of some instruments, affects the accuracy of the test, and hinders the further miniaturization of household instruments.

[0005] Therefore, how to provide a valve device for pressure, flow and time monitoring and control for exhalation detection that can integrate the pressure, flow and time monitoring and control functions into one, simplify the structure, reduce the dead space volume, reduce the cost, and have higher reliability and stability is one of the technical problems that need to be urgently solved in this field. Summary of the invention

[0006] In view of this, the present invention provides a valve device for monitoring and regulating pressure, flow and time for exhalation detection, which can directly calculate the flow through displacement changes, replacing traditional pressure sensors and flow sensors. The valve device integrates pressure monitoring, flow monitoring, resistance control and valve closing time control functions.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A valve device for monitoring and regulating pressure, flow and time for exhalation detection, comprising: a supporting shell, a spring, a valve core and an orifice plate; the orifice plate is arranged at one end of the supporting shell; the valve core is arranged inside the supporting shell; the spring is sleeved on the valve core; the valve core is provided with a valve head near one end of the orifice plate; a through hole corresponding to the valve head is opened on the orifice plate; the spring is made of semiconductor material.

[0009] Preferably, the flow rate is calculated by the following formula:

[0010]

[0011]

[0012] Where Q is the flow rate; F1 is the force applied by the spring; K s is the sensitivity coefficient; K f is the spring stiffness (N / m); ΔR is the change in resistance; A is the effective area of ​​the valve core opening; ρ is the fluid density; P is the pressure; and C1 is the flow coefficient.

[0013] Preferably, the valve head opening shape is a parabola shape, so that the relationship between fluid flow and displacement is linearized, flow calculation is simplified, and the conversion relationship between flow and opening height is obtained by combining the fluid continuity equation and the Bernoulli equation:

[0014]

[0015] Among them, F2 is the pressure; x is the horizontal position of the opening; a is the opening width coefficient of the parabola, which determines the degree of opening of the parabola; (m,n) are the vertex coordinates of the parabola; x1 and x2 are the left and right boundaries of the opening; S is the area of ​​the through hole (241); and d is the displacement.

[0016] Compared with the prior art, the present invention has achieved the following technical effects:

[0017] 1) The present invention can directly calculate the flow rate through displacement changes, replacing traditional pressure sensors and flow sensors, integrating pressure monitoring, flow measurement, resistance control and valve closing time control functions into one, with a compact and simplified overall design, reducing dead space volume, reducing costs, and having higher reliability and stability.

[0018] 2) The present invention can effectively replace traditional pressure sensors through innovative displacement measurement and valve core design to achieve more efficient flow monitoring and control. This technology has broad application prospects and can be promoted and applied in the field of breath detection, with significant market value and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of a valve device for monitoring and controlling pressure, flow rate and time for breath detection in an initial state and a closed state according to the present invention;

[0020] Figure 2 It is a schematic diagram of a valve device for monitoring and controlling pressure, flow rate and time for exhalation detection in the exhalation state according to the present invention;

[0021] Figure 3 Schematic diagram of the correlation between the CeNO (50 ml / s) measurement results of the prototype of the present invention and the breath analyzer Sunvou-CA2122;

[0022] Figure 4 Schematic diagram of consistency between the CeNO (50 ml / s) measurement results of the prototype of the present invention and the breath analyzer Sunvou-CA2122;

[0023] In the figure: 210, support shell; 220, spring; 230, valve core; 231, valve head; 240, orifice plate; 241, through hole. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example

[0026] Reference Figure 1-4As shown, the present invention discloses a valve device for monitoring and regulating pressure, flow and time for exhalation detection, comprising: a supporting shell 210, a spring 220, a valve core 230 and an orifice plate 240; the orifice plate 240 is arranged at one end of the supporting shell 210; the valve core 230 is arranged inside the supporting shell 210; the spring 220 is sleeved on the valve core 230; a valve head 231 is provided at one end of the valve core 230 close to the orifice plate 240; a through hole 241 corresponding to the valve head 231 is opened on the orifice plate 240; the spring 220 is made of semiconductor material, has high sensitivity to external pressure and displacement changes, and is convenient for displacement measurement; when in use, as the valve core 230 reciprocates, it penetrates into the through hole 241 to achieve a change in the aperture.

[0027] In this embodiment, the spring 220 is made of semiconductor materials for displacement measurement. These materials are highly sensitive to external pressure and displacement changes. The semiconductor materials that can be selected are silicon-based semiconductor materials, indium tin oxide, etc. By measuring the resistance, inductance, current or magnetic flux changes of semiconductor materials, the displacement deformation is accurately calculated, thereby achieving accurate measurement of flow. It can maintain good elasticity and deformation characteristics under different environmental conditions, ensuring the stability of the valve under high-frequency operation.

[0028] The working process of this integrated valve is:

[0029] Initial state: See Figure 1 , the valve core 230 is in the initial state. At this time, the valve core 230 is affected by the compression force of the spring 220 and stays in the initial position on the right. At this time, the displacement of the spring 220 is d0. The starting pressure value P0 is set. According to the following formula, the valve is in the closed state. At this time, the flow rate is 0 and the resistance is 0.

[0030] Exhalation state: When gas enters the valve head 231 at the front end of the valve core 230, the spring 220 will be deformed and compressed as the gas flow increases, and the displacement change is d1. According to the change in displacement and the change in the resistance value of the spring 220, the pressure and flow value at this time are calculated. In this process, the elastic compression force of the spring 220 can ensure that the resistance in the entire ventilation process is kept within a certain range, thereby realizing the monitoring of the exhalation pressure and flow, and the control of the resistance in the valve, see Figure 2 .

[0031] Reset state: When ventilation is completed, the spring 220 returns to its original state and closes the valve. Figure 1 .

[0032] In this example, the displacement is calculated by measuring the change in resistance of the semiconductor material:

[0033] d=K s ΔR

[0034] F1=K f ·d=K s K f ΔR

[0035] Where d is the displacement; F1 is the force applied by the spring; K s is the sensitivity coefficient; K f is the spring stiffness (N / m); ΔR is the change in resistance.

[0036] In this embodiment, the relationship between the flow rate Q and the displacement d is expressed by the following formula:

[0037] Q=A·v d

[0038] Where Q is the flow rate; A is the effective area of ​​the valve core opening; v d is the fluid velocity related to the displacement.

[0039] In this embodiment, according to fluid dynamics and Bernoulli's equation, the pressure can be calculated by the following formula:

[0040]

[0041] Among them, ρ is the fluid density; P is the pressure; P1 is the static pressure at the valve inlet; P0 is the static pressure at the valve outlet; C1 is the flow coefficient.

[0042] In this embodiment, the above formulas can be combined to obtain:

[0043]

[0044] In this embodiment, the opening shape of the valve head 231 is a parabola shape, so that the relationship between fluid flow and displacement is linearized, simplifying flow calculation.

[0045] In this embodiment, the fluid flow path is optimized, the flow resistance is reduced, and the flow efficiency is improved through precise opening design.

[0046] In this embodiment, in the design of the opening shape of the valve head 231, the shape of the parabolic opening is described by the following standard equation:

[0047] y=a(xm) 2 +n

[0048] Among them, y is the height of the opening (vertical direction); x is the horizontal position of the opening; a is the opening width coefficient of the parabola, which determines the degree of opening of the parabola; (m,n) are the vertex coordinates of the parabola.

[0049] In this embodiment, the effective area A of the parabola opening can be obtained by integral calculation:

[0050]

[0051] Wherein, x1 and x2 are the left and right boundaries of the opening; S is the area of ​​the through hole (241).

[0052] Substituting the parabola equation into this equation, we get:

[0053]

[0054] After integration, the specific expression of the effective area can be obtained.

[0055] The conversion relationship between flow rate and opening height is obtained by combining the continuity equation of the fluid and the Bernoulli equation:

[0056]

[0057] The flow value Q and pressure value F2 can be obtained through the above formula.

[0058] The valve device for monitoring and controlling pressure, flow and time for breath detection provided by the present invention integrates the pressure, flow and time monitoring and controlling functions in breath detection into one, and the overall design is compact and simplified, which reduces the dead space volume, reduces the cost, and has higher reliability and stability.

[0059] The parabolic opening design can effectively control the fluid flow rate. The parabolic equation can be used to accurately calculate the geometric characteristics of the opening. Combined with the basic principles of fluid dynamics, the conversion relationship between the flow rate and the valve core opening height can be established to achieve precise control of the flow rate.

[0060] The specific implementation of this device:

[0061] Based on the principle of fluid mechanics and the simulation results of the fluid model, the opening shape of the valve head 231 at the front end of the valve core 230 adopts a parabolic shape, so that the relationship between fluid flow and displacement is linearized, simplifying the flow calculation. When the exhalation flow rate is 50mL / s, the valve head 231 adopts a conical shape. When the maximum diameter is designed to be 5mm, the diameter of the valve core 230 is 13mm, the tanθ of the cone half angle is approximately 1 / 12, the length is designed to be 20mm, and the diameter of the through hole 241 on the orifice plate 240 is designed to be 14mm. During the exhalation process of the device, when the valve head 231 moves forward to the maximum opening and closing of the valve, the resistance is 10cmH2O, and when the valve head 231 retreats to the minimum opening and closing of the valve, the resistance is 5cmH2O, ensuring that the exhalation resistance can be controlled at 5-10cmH2O during the entire exhalation process. Through precise opening design, the fluid flow path is optimized, the flow resistance is reduced, and the flow efficiency is improved.

[0062] According to the technical solution of the present invention, a prototype of the present invention is designed and manufactured. The valve device of the present invention omits the pressure sensor, flow sensor and solenoid valve, making the structure more compact and the appearance more exquisite, and the cost is less than 20% of the breath analyzer Sunvou-CA2122.

[0063] A crowd simulation test was conducted, and the prototype of the present invention was compared with the breath analyzer Sunvou-CA2122 for experience. The experience data can be seen in Table 1.

[0064] Table 1 Actual experience ratings of the subjects

[0065]

[0066]

[0067] Figure 3 20 volunteers were tested using the prototype of the present invention and the breath analyzer Sunvou-CA2122. NO The results of the (50ml / s) test were compared (each method was measured 3 times, and the average was taken for comparison). The consistency of the two results is shown in the figure. The linear correlation analysis is good, and the Pearson correlation is 0.9991 (P<0.001). The two are strongly correlated. The Bland-Altman plot is compared ( Figure 4 ), the measurement differences between the two groups were within the 95% confidence interval, and clinically the results of the two measurement methods can be considered consistent.

[0068] From the experience results, the prototype of the present invention has a significant improvement over the breath analyzer Sunvou-CA2122, and all subjects were able to successfully take samples at one time. The consistency with the exhaled nitric oxide measurement results of the breath analyzer Sunvou-CA2122 meets the clinical indicator requirements.

[0069] In some other embodiments, a displacement resistor or a spring strain gauge may be used to link the valve core, and the pressure and flow rate may be calculated through the displacement change of the valve core.

[0070] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A valve device for monitoring and controlling pressure, flow and time for breath detection, characterized in that: include: A support shell (210), a spring (220), a valve core (230) and an orifice plate (240); the orifice plate (240) is arranged at one end of the support shell (210); the valve core (230) is arranged inside the support shell (210); the spring (220) is sleeved on the valve core (230); a valve head (231) is provided at one end of the valve core (230) close to the orifice plate (240); a through hole (241) corresponding to the valve head (231) is opened on the orifice plate (240); the spring (220) is made of semiconductor material.

2. A valve device for monitoring and controlling pressure, flow and time for breath detection according to claim 1, characterized in that: The flow rate is calculated using the following formula: Where Q is the flow rate; F1 is the force applied by the spring; K s is the sensitivity coefficient; K f is the spring stiffness; ΔR is the change in resistance; A is the effective area of ​​the valve core opening; ρ is the fluid density; P is the pressure; C1 is the flow coefficient.

3. A valve device for monitoring and controlling pressure, flow and time for breath detection according to claim 1, characterized in that: The opening shape of the valve head (231) is a parabola shape, so that the relationship between fluid flow and displacement is linearized, flow calculation is simplified, and the conversion relationship between flow and opening height is obtained by combining the fluid continuity equation and the Bernoulli equation: Among them, F2 is the pressure; x is the horizontal position of the opening; a is the opening width coefficient of the parabola, which determines the degree of opening of the parabola; (m,n) are the vertex coordinates of the parabola; x1 and x2 are the left and right boundaries of the opening; S is the area of ​​the through hole (241); and d is the displacement.

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