Diaphragm pressure detection device and blood circuit

Abstract

The utility model discloses a diaphragm pressure detection device and blood circuit belongs to blood purification equipment technical field, including shell, the shell inside has the receiving space, the elastic membrane is installed on the shell, and will the receiving space is divided into by first shell portion covers first receiving space and by second shell portion covers second receiving space, the respective peripheral portion of first shell portion and second shell portion is equipped with the clamping face, and the clamping face is used for clamping the periphery of elastic membrane, the elastic membrane has the detection face, and the detection face is in the tension state and is equipped with one detection datum plane, and the elastic membrane is configured as when the pressure of first receiving space with second receiving space is equal, the elastic membrane detection face with detection datum plane coincides. The utility model makes the elastic membrane under different pressure impact can restore the initial state, and effectively promotes pressure detection precision.

Description

Technical Field

[0001] This utility model relates to the field of blood purification equipment technology, specifically to a diaphragm pressure detection device and a blood circuit. Background Technology

[0002] During blood purification or hemodialysis treatment, real-time pressure monitoring at multiple critical locations is necessary to ensure the safety of the extracorporeal circulation tubing. Currently, mainstream pressure monitoring systems mainly consist of a disposable pressure cartridge integrated into the tubing consumables and a pressure sensor interface on the blood purification equipment. Among these, the pressure cartridge, as the core component for pressure transmission, directly determines the accuracy and reliability of pressure measurement through its structural design.

[0003] Existing pressure chambers typically employ a flexible diaphragm to divide the internal structure into two independent chambers: a fluid chamber and a gas chamber. The fluid chamber is in direct contact with the blood or dialysate; pressure changes generated as the liquid flows through the tubing directly affect the flexible diaphragm. The gas chamber is connected to a pressure sensor on the blood purification device. The flexible diaphragm deforms under fluid pressure, altering the gas pressure within the gas chamber. The pressure sensor detects this pressure change to indirectly calculate the actual fluid pressure in the fluid chamber, achieving non-contact pressure measurement.

[0004] To ensure the airtightness of the pressure chamber and prevent liquid leakage in the fluid chamber or gas loss in the gas chamber, existing flexible diaphragm mounting structures for pressure chambers primarily rely on mechanical compression sealing between the upper and lower shells. This involves creating sealing grooves on the shells, placing the edges of the flexible diaphragm within these grooves, and utilizing the compression force during assembly to deform the diaphragm edges, thereby achieving a seal between the chambers. However, this traditional mechanical compression mounting structure has significant drawbacks in practical applications, leading to the following problems: First, there is measurement bias. Due to the residual deformation of the flexible diaphragm under repeated pressure impacts, the pressure reading fluctuates continuously between the initial value and the calibration value, which cannot stably reflect the actual fluid pressure, seriously reducing the accuracy of pressure measurement and potentially leading to misjudgment of the pipeline pressure status by medical staff. Secondly, the long-term stability is insufficient. Under long-term pressure shock cycles, the resilience of the flexible diaphragm will gradually degrade, and the cumulative effect of residual deformation will intensify, causing significant drift in pressure measurement data. As the usage time increases, the measurement error continues to expand, making it difficult to meet the needs of long-term stable monitoring during blood purification treatment. Third, the measurement repeatability is poor. When multiple measurements are performed under the same pressure conditions, the residual deformation of the flexible diaphragm after each compression is inconsistent, resulting in significant differences in the measurement results. The large dispersion of the measurement data reduces the reliability of the pressure monitoring results and fails to provide stable and reliable data support for treatment safety.

[0005] Therefore, there is an urgent need for a diaphragm pressure detection device that can restore the flexible diaphragm to its initial state under different pressure impacts, thereby improving the stability and repeatability of pressure measurement and achieving high-precision pressure detection. Utility Model Content

[0006] To address the problems existing in the prior art, this utility model provides a diaphragm-type pressure detection device and blood circuit, aiming to solve the problems of measurement deviation, insufficient long-term stability, and poor measurement repeatability caused by the residual deformation of the flexible diaphragm due to the mechanical compression sealing structure of the existing diaphragm pressure box. To achieve the above objectives, this utility model provides the following technical solution: A diaphragm pressure detection device, comprising: The housing includes a first housing portion and a second housing portion that fits into the first housing portion, and the housing has an internal receiving space; An elastic membrane is mounted on the outer shell and divides the receiving space into a first receiving space covered by the first outer shell portion and a second receiving space covered by the second outer shell portion; each of the first outer shell portion and the second outer shell portion has a clamping surface at its peripheral edge for clamping the periphery of the elastic membrane. The elastic membrane has a detection surface, which is in a tensioned state and has a detection reference surface. The elastic membrane is configured such that when the pressure of the first receiving space and the second receiving space are equal, the detection surface of the elastic membrane coincides with the detection reference surface.

[0007] Furthermore, the tail end of the second outer shell is provided with a groove, which is used to provide pre-assembly positioning for the elastic membrane, and the inner diameter of the groove is larger than the inner diameter of the elastic membrane to form an interference fit.

[0008] Furthermore, the tensile strength of the elastic membrane detection surface is 0.1% to 100%; the Shore hardness value of the elastic membrane is X HA; the diameter of the elastic membrane detection surface is Y mm; and the value of X / Y ranges from 1 to 5.

[0009] Furthermore, the Shore hardness value of the elastic membrane ranges from 20HA to 50HA; the diameter of the detection surface of the elastic membrane ranges from 2mm to 25mm.

[0010] Furthermore, the tensile strength of the elastic membrane detection surface is 0.1% to 50%, and the X / Y value ranges from 1 to 3.

[0011] Furthermore, the detection reference surface is a plane.

[0012] Furthermore, the elastic membrane has a thickened portion around its periphery, and the thickened portion protrudes from one side of the detection surface.

[0013] Furthermore, it also includes a fixing part for fixing the first outer shell part and the second outer shell part in a mating state; the fixing part includes a stepped bearing end disposed on the periphery of the second outer shell part, and a stepped docking end disposed on the periphery of the first outer shell part and adapted to the stepped bearing end. It also includes a sealing part for sealing the elastic membrane held by the clamping surface at its entire circumference; the sealing part is a sealing cavity, and the first outer shell part and the second outer shell part are each provided with a corresponding half cavity, which are assembled to form a complete sealing cavity; the thickened part of the elastic membrane is located in the sealing cavity.

[0014] Furthermore, the free end of the second outer casing is provided with a Luer connector.

[0015] A blood circuit includes a tubing and at least one diaphragm pressure detection device connected to the tubing and employing the aforementioned method.

[0016] The beneficial effects of this utility model are: The diaphragm pressure detection device and blood circuit provided by this utility model, by setting the elastic membrane detection surface to a tensioned state and through the synergistic effect of the clamping surface and the sealing part, allows the flexible diaphragm to return to its initial state when the pressure in the first receiving space and the second receiving space are equal under repeated pressure impacts in the liquid chamber. This effectively avoids residual deformation of the elastic membrane, significantly improves the accuracy, stability and repeatability of pressure measurement, and is also reliable in sealing and easy to assemble. It is suitable for the pressure monitoring needs of blood circuits and provides reliable protection for pressure monitoring in medical treatment. Attached Figure Description

[0017] Figure 1 A schematic diagram of the overall structure of a diaphragm-type pressure detection device provided by this utility model; Figure 2 A schematic diagram showing the elastic membrane provided by this utility model fitting into the second outer shell. Figure 3 A cross-sectional view of a diaphragm pressure detection device provided by this utility model; Figure 4 A cross-sectional view of the second outer shell portion provided by this utility model; Figure 5 A schematic diagram of the fixing part provided by this utility model; The reference numerals in the attached drawings are: 1, first outer shell; 2, elastic membrane; 3, second outer shell; 4, sealing part; 5, fixing part; 6, groove. Detailed Implementation

[0018] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and are not intended to limit its scope of protection. Those skilled in the art should understand that the present invention can be implemented even without certain specific details. In other embodiments, methods, means, equipment, and steps well-known to those skilled in the art are not described in detail to highlight the essence of the present invention.

[0019] Unless otherwise specified, in this utility model, terms such as "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," "x-direction," "y-direction," and "z-direction" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe orientation or positional relationships in this utility model are for illustrative purposes only and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood in conjunction with the accompanying drawings and according to the specific circumstances.

[0020] In at least one embodiment, see Appendix Figures 1-5 This embodiment provides a diaphragm pressure detection device, including a housing and an elastic diaphragm 2, the specific structures of each part are as follows: The outer shell includes a first outer shell portion 1 and a second outer shell portion 3, which are sized to fit each other and can be injection molded from medical-grade ABS material. The first outer shell portion 1 and the second outer shell portion 3 are mated together at their periphery, forming an internal receiving space after mating. Each periphery of the first outer shell portion 1 and the second outer shell portion 3 is machined with an annular clamping surface, which can be used to stably clamp the periphery of the elastic membrane 2. The tail end, i.e., the periphery of the second outer shell portion 3, is provided with an annular groove 6, which is used for pre-assembly positioning of the elastic membrane 2. Each periphery of the first outer shell portion 1 and the second outer shell portion 3 is provided with a fixing portion 5, which is used to fix the first outer shell portion 1 and the second outer shell portion 3 when they are mated. For example, the periphery of the second outer shell portion 3 is provided with a stepped bearing end, and the periphery of the first outer shell portion 1 is provided with a stepped mating end that matches the stepped bearing end. The outer shell also includes a sealing portion 4, which is actually a sealing cavity in this application, wherein each of the first outer shell portion 1 and the second outer shell portion 3 is provided with a corresponding semi-cavity, which forms a complete sealing cavity after assembly. The thickened portion with raised edges of the elastic membrane 2 is located in the sealing cavity. The thickened portion facilitates installation and can be squeezed to fill the sealing cavity during the assembly of the first outer shell 1 and the second outer shell 3. At the same time, glue can be placed in the sealing cavity to fix and seal all components of the entire detection device.

[0021] The elastic membrane 2 can be made of medical-grade silicone rubber material, manufactured through an integral injection molding process, and meets biocompatibility standards. The elastic membrane 2 is circular in shape, and its detection surface is a circular plane. A thickened portion is provided around the periphery of the elastic membrane 2, protruding from one side of the detection surface. This thickened portion facilitates installation and also serves to fill the gap when the first outer shell 1 and the second outer shell 3 are assembled. The inner diameter of the groove 6 is larger than the inner diameter of the elastic membrane 2 to form an interference fit. During assembly, after the edge of the elastic membrane 2 is embedded in the groove 6, the interference fit generates uniform pretension, naturally keeping the detection surface taut. The detection reference surface of the elastic membrane 2 is set as a plane adapted to the detection surface. When the pressure of the first receiving space and the second receiving space are equal, the detection surface of the elastic membrane 2 coincides with the detection reference surface. The first receiving space is in contact with the fluid, and the second receiving space is connected to the sensor.

[0022] During assembly, the second outer shell 3 and the elastic membrane 2 installed on the second outer shell 3 form a whole, and then are welded to the first outer shell 1; the first outer shell 1 and the second outer shell 3 form an assembly structure that clamps and fixes the elastic membrane 2 from the top and bottom. With the help of ultrasonic welding, the elastic membrane 2 finally forms a separate seal for the first outer shell 1 and the second outer shell 3. The free end of the second outer shell 3 is also provided with a Luer connector, which allows for standardized, rapid, and sealed connection of the detection device to external components such as pressure sensor connection pipes, gas ducts, etc.

[0023] Its working process is as follows: When this device is used for blood circuit pressure monitoring, the first receiving space is connected to the blood circuit tubing via an interface, and the second receiving space is connected to the pressure sensor via an air tube. As blood flows through the tubing, fluid pressure acts on one side of the elastic diaphragm 2, i.e., the first receiving space side, causing the detection surface of the elastic diaphragm 2 to deform and deviate from the detection reference surface. This deformation of the elastic diaphragm 2 results in a change in air pressure within the second receiving space. The pressure sensor detects this pressure change and converts it into an electrical signal, which is transmitted to the control system. When the pressure in the tubing decreases or returns to its initial state, the elastic diaphragm 2 resets under pre-tension and its own elasticity, and the detection surface re-aligns with the detection reference surface, ensuring consistency in the initial state for the next measurement.

[0024] In at least one embodiment, the diameter of the detection surface of the elastic membrane 2 is stretched to 100.1% to 200% of its initial state, i.e., the stretching rate is 0.1% to 100%; the Shore hardness value of the elastic membrane 2 is X HA, the diameter of the detection surface of the elastic membrane 2 is Y mm, and the value of X / Y ranges from 1 to 5; preferably, the stretching rate of the detection surface of the elastic membrane 2 is 0.1% to 50%, and the value of X / Y ranges from 1 to 3; the Shore hardness value of the elastic membrane 2 ranges from 20 HA to 50 HA, preferably, the Shore hardness of the elastic membrane 2 is 30 HA; the diameter of the detection surface of the elastic membrane 2 ranges from 2 mm to 25 mm. Preferably, the natural frequency f0 of the diaphragm must be higher than the frequency of the pressure being measured. For example, if measuring a 100 Hz pulsating pressure, f0 needs to be > 500 Hz, otherwise the dynamic error will be > 1%.

[0025] The present invention was compared with existing technologies in a test. Items 2-12 all adopted the mounting structure and diaphragm structure of the present invention, while item 1 adopted a conventional mounting structure and diaphragm structure in existing technologies, where the elastic diaphragm 2 has a thicker edge and a thinner detection area. The X / Y values ​​and elongation rate were taken from the data in Table 1. Pressure testing was then performed on a pressure testing device. The meter display shows the pressure value given by the test, while the machine display shows the pressure values ​​detected by items 1-12. Each test group underwent 5-10 tests, and the average value was taken.

[0026] Table 1 Summary of Test Data

[0027] The test results from numbers 2-8 show that when the X / Y value ranges from 1 to 5 and the elongation rate is 0.1%-100%, the measurement deviation is small and the stability is high, with strong measurement repeatability. The overall measured pressure value meets the requirements and has high accuracy. The test results from numbers 1 and 2-8 show that tensioning the elastic membrane 2 significantly improves the overall pressure detection accuracy and stability. The elongation rate in number 1 is 0, equivalent to the fixed structure of the elastic membrane 2 in the prior art. In this structure, the edge of the elastic membrane 2 is thick while the detection area is thin. This causes the edge of the elastic membrane 2 to stretch inwards and outwards after being pressed by the first outer shell 1 and the second outer shell 3, resulting in a relaxed detection area that bounces back and forth on the detection reference surface. This leads to severe data drift in number 1, and under the same pressure conditions, multiple measurements are inconsistent with huge measurement deviations, failing to meet the pressure detection requirements.

[0028] In at least one embodiment, this embodiment also provides a blood circuit, including a tubing and at least one diaphragm-type pressure detection device connected to the tubing. Specifically, the blood circuit includes a main tubing, branch tubing, and the diaphragm-type pressure detection device as described in any of the above embodiments. The main tubing can be made of medical-grade PVC material. One end of the branch tubing is connected to the tee port of the main tubing, and the other end is connected to the first receiving space inlet of the diaphragm-type pressure detection device via a quick-connect coupling. A shut-off valve is provided on the branch tubing to control whether pressure detection is connected according to monitoring needs. In this blood circuit, a diaphragm-type pressure detection device can be connected to the inlet end of the main tubing, the rear end of the pump, and the dialyzer inlet end, respectively, to achieve multi-point synchronous pressure monitoring. The detection data from each device is transmitted in real time to the display screen of the blood purification equipment, facilitating medical personnel to monitor the tubing pressure status in real time and handle abnormal situations promptly.

[0029] The above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications and substitutions should be covered within the scope of the claims of this utility model. Technologies, shapes, and structural parts not described in detail in this utility model are all known technologies.

Claims

1. A diaphragm-type pressure detection device, characterized in that, include: The outer casing includes a first outer casing portion (1) and a second outer casing portion (3) that matches the first outer casing portion (1), and the interior of the outer casing has a receiving space; An elastic membrane (2) is mounted on the outer shell and divides the receiving space into a first receiving space covered by the first outer shell portion (1) and a second receiving space covered by the second outer shell portion (3); each of the first outer shell portion (1) and the second outer shell portion (3) has a clamping surface at its periphery, which is used to clamp the periphery of the elastic membrane (2); The elastic membrane (2) has a detection surface, which is in a tensioned state and has a detection reference surface. The elastic membrane (2) is configured such that when the pressure of the first receiving space and the second receiving space are equal, the detection surface of the elastic membrane (2) coincides with the detection reference surface.

2. The diaphragm pressure detection device according to claim 1, characterized in that, The tail end of the second outer shell (3) is provided with a groove (6), which is used to provide pre-assembly positioning for the elastic membrane (2), and the inner diameter of the groove (6) is larger than the inner diameter of the elastic membrane (2) to form an interference fit.

3. The diaphragm pressure detection device according to claim 1, characterized in that, The tensile strength of the detection surface of the elastic membrane (2) is 0.1% to 100%; the Shore hardness of the elastic membrane (2) is X HA; the diameter of the detection surface of the elastic membrane (2) is Y mm; and the value of X / Y is 1 to 5.

4. The diaphragm pressure detection device according to any one of claims 1-3, characterized in that, The Shore hardness value of the elastic membrane (2) ranges from 20HA to 50HA; the diameter of the detection surface of the elastic membrane (2) ranges from 2mm to 25mm.

5. The diaphragm pressure detection device according to claim 3, characterized in that, The stretching ratio of the detection surface of the elastic membrane (2) is 0.1% to 50%, and the X / Y value ranges from 1 to 3.

6. The diaphragm pressure detection device according to any one of claims 1-3 or 5, characterized in that, The detection reference surface is a plane.

7. The diaphragm pressure detection device according to any one of claims 1-3 or 5, characterized in that, The elastic membrane (2) has a thickened portion around its periphery, and the thickened portion protrudes from one side of the detection surface.

8. The diaphragm pressure detection device according to claim 7, characterized in that, It also includes a fixing part (5) for fixing the first outer shell part (1) and the second outer shell part (3) in a mating state; the fixing part (5) includes a stepped bearing end provided on the periphery of the second outer shell part (3) and a stepped docking end provided on the periphery of the first outer shell part (1) and adapted to the stepped bearing end; It also includes a sealing part (4) for sealing the elastic membrane (2) held by the clamping surface at its entire periphery; the sealing part (4) is a sealing cavity, and the first outer shell part (1) and the second outer shell part (3) are each provided with a half cavity, which are assembled to form a complete sealing cavity; the thickened part of the elastic membrane (2) is located in the sealing cavity.

9. The diaphragm pressure detection device according to any one of claims 1-3, 5 or 8, characterized in that, The second outer casing (3) has a Luer connector at its free end.

10. A blood circuit, characterized in that, It includes a pipeline and at least one diaphragm pressure detection device connected to the pipeline and employing any one of claims 1 to 9.

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