Membranes, pressure measuring devices, and extracorporeal circulation tubing

Abstract

This invention relates to a diaphragm (12) for a pressure measuring device, comprising a resilient circular diaphragm (120) for sealing one side of the pressure measuring device (10), thereby forming a gap between the interior and exterior of the pressure measuring device; wherein the resilient circular diaphragm (120) is horizontally fixed to the surface of the chamber of the pressure measuring device (10) via a peripheral portion of the diaphragm (12) away from the center; and the resilient circular diaphragm (120) is flat when there is no pressure difference between the pressures acting on the inner surface (121) and the outer surface (122), respectively. The invention also relates to a pressure measuring device and an extracorporeal circulation tubing, which are manufactured using simple and reliable technology, saving materials and manufacturing costs while maintaining accurate pressure measurement.

Description

Technical Field

[0001] This invention relates to a membrane for use in a pressure measuring device, used to measure pressure within a pipeline, particularly in an extracorporeal circulation pipeline. The invention also relates to a pressure measuring device and an extracorporeal circulation pipeline of a corresponding pressure measuring device having such a membrane. Background Technology

[0002] Dialysis is a treatment method, such as hemodialysis (HD) or continuous renal replacement therapy (CRRT), used to remove toxic substances and metabolites that are normally removed by the kidneys and to help regulate fluid and electrolyte balance; it is usually performed using a dialysis machine and dialysate generated online or prepared in advance.

[0003] Taking hemodialysis as an example, during extracorporeal circulation, the pressure within the tubing must be closely monitored to ensure the quality and safety of the entire treatment process. For this purpose, the machines used for treatment are typically equipped with specially designed sensors, which are among the most critical components of the dialysis machine. Clearly, it is necessary to prevent fluid contamination of these sensors, which are designed for reuse, from entering the tubing. Furthermore, extracorporeal circulation is performed using disposable tubing.

[0004] Therefore, it is well known to provide at least one pressure chamber in the circuit, often referred to as a "pressure dome," suitable for providing an interface between the tubing and the pressure sensor. This pressure dome typically consists of a housing with an inlet and an outlet connected to the circuit. Finally, a flexible diaphragm or sheet seals one side of the cavity and serves as contact with the pressure sensor. The flexible diaphragm, with its high elasticity, transmits pressure and changes within the circuit to the sensor.

[0005] Although these pressure domes were invented many years ago and have been widely used, they are not perfect.

[0006] This pressure dome is described in detail in US Patent 7,603,907. Figure 1 An embodiment of this is illustrated in the diagram. One of its main drawbacks is that air can seep between the membrane and the sensor. This can occur, for example, when the sensor is engaged with the pressure dome. Air may remain between the two surfaces that should be in direct contact when positioning the sensor. In this case, the sensor will not be able to adequately measure the chamber pressure or respond reliably to pressure changes.

[0007] Another problem with this pressure dome relates to the manufacturing technology used at the time. The main body 10 of the chamber was made of a molding polymer with sufficient rigidity to be suitable for contact with physiological fluids. The elastomeric membrane 12, on the other hand, was made using a two-component injection molding process, which, in addition to manufacturing the elastomeric membrane itself, also included a retaining ring 14 made of a rigid polymer, for example, used to manufacture the main body. Thus, the elastomeric membrane and the associated retaining ring formed a single component made of two different materials. They were then connected to the main body using screws / threads, snap-fit ​​joints, interference fits, or similar connections. Obviously, manufacturing such a pressure dome involving two-component injection molding required the use of molds with moving parts, which are complex to manufacture and use. Furthermore, the initial cost of these moving part molds was significantly higher than that of conventional molds.

[0008] To overcome the above-mentioned shortcomings, US Patent 9,050,417 describes other pressure domes in detail. Figure 2 An embodiment of it is illustrated.

[0009] like Figure 2 As shown, this type of membrane 12 includes a resilient circular wall 120 for closing one side of the pressure dome 10, thereby forming a partition between the interior and exterior of the pressure dome; a circular edge 124 for connecting to the body 16 of the pressure dome 10; wherein the resilient circular wall 120 has an outwardly convex shape when there is no difference in pressure acting on the inner surface 121 and the outer surface 122 respectively. In other words, the membrane 12 is not planar but has a double curvature. For example, the resilient circular wall 120 has a cap-like shape, wherein the cap forms part of a sphere or other rotating entity.

[0010] The pressure dome with this convex diaphragm reduces the possibility of air entering the pressure sensor junction, which seems to solve the problem. Figure 1 The first drawback of the design shown is that it creates similar manufacturing problems, including the need for precise manufacturing of this particular membrane and the need to precisely maintain the convexity of the membrane after assembly, as this must be achieved through deformation of the edge 164, a technique known as crimping. Therefore, the body 16 also includes a base 162 for stably mounting the membrane 12; this base 162 is specifically formed to receive the flange 124 of the membrane 12. Furthermore, the base 162 is defined by the edge 164 and the inner wall 165. The edge 164 is folded up to abut against the flange 124 of the membrane 12, thereby holding it within the corresponding base 162. Therefore, from a manufacturing perspective, the body 16 of the pressure dome 10 is designed to be more complex than previous bodies. Summary of the Invention

[0011] In view of at least one problem existing in the prior art, the object of the present invention is to overcome at least partially the disadvantages of the prior art described above.

[0012] According to one aspect of the invention, a membrane for a pressure measuring device is provided, comprising an elastic circular diaphragm for closing one side of the pressure measuring device, thereby forming a gap between the interior and exterior of the pressure measuring device; wherein the elastic circular diaphragm is horizontally fixed to the surface of the chamber of the pressure measuring device via a peripheral portion of the membrane away from the center; and the elastic circular diaphragm is flat when there is no pressure difference between the pressures acting on the inner and outer surfaces respectively.

[0013] According to an alternative embodiment of the invention, the resilient circular diaphragm does not have a ring made of a rigid polymer for securing the periphery of the diaphragm; and / or the resilient circular diaphragm is not associated with a ring for securing the periphery of the diaphragm.

[0014] According to an alternative embodiment of the invention, the elastic circular diaphragm does not have a circular flange for engagement with the body of the pressure measuring device.

[0015] According to an optional embodiment of the invention, the membrane is made of thermoplastic elastomer (TPE), preferably thermoplastic polyurethane (TPU).

[0016] According to an alternative embodiment of the invention, the membrane or elastic circular membrane is made of polyvinyl chloride (PVC).

[0017] According to an optional embodiment of the invention, the thickness of the membrane or elastic circular diaphragm is between 0.25 mm and 0.4 mm.

[0018] According to an optional embodiment of the invention, the Shore A hardness of the membrane or elastic circular diaphragm is between 80A and 90A.

[0019] According to an alternative embodiment of the invention, the membrane is welded to the surface of the chamber of the pressure measuring device.

[0020] According to a second aspect of the invention, a pressure measuring device for cooperation with a pressure sensor is provided, comprising a body defining an inlet and an outlet suitable for allowing liquid to be connected to a pipe, wherein the pressure measuring device further comprises the aforementioned membrane.

[0021] According to an alternative embodiment of the invention, the body has a surface for horizontally mounting the membrane, and the body does not have a base for defining the membrane by the edge portion and / or inner wall.

[0022] According to an alternative embodiment of the invention, the body is manufactured by injection molding a polymer that is sufficiently rigid and suitable for contact with physiological fluids.

[0023] According to an optional embodiment of the invention, the polymer is selected from the group consisting of polycarbonate (PC), rigid polyvinyl chloride (PVC), and methyl methacrylate acrylonitrile butadiene styrene (MABS).

[0024] According to an optional embodiment of the invention, the body includes a protrusion and a collar portion; and the periphery of the membrane is welded to a surface between the protrusion and the collar portion.

[0025] According to an optional embodiment of the invention, the outer periphery of the membrane is flat after welding.

[0026] According to an alternative embodiment of the invention, after the periphery of the membrane is welded, the pressure measuring device is sealed as a whole.

[0027] According to an optional embodiment of the invention, the inner surface of the collar portion has an inclined surface extending to the surface between the protrusion and the collar portion.

[0028] According to an alternative embodiment of the invention, the protrusion is positioned much lower than the inner wall.

[0029] According to an alternative embodiment of the invention, the body further includes a pressing component for facilitating installation of the pressure measuring device.

[0030] According to an optional embodiment of the invention, the pressing component is either an integrally molded component of the main body or a component separately assembled onto the main body.

[0031] According to a third aspect of the invention, an extracorporeal circulation tubing with a pressure measuring device is provided, wherein the pressure measuring device is used to monitor at least one blood pressure before or after a dialyzer.

[0032] According to the present invention, a membrane and its pressure measuring device are provided that can be manufactured using simple and reliable techniques, while achieving a high quality level comparable to known types of pressure domes. Attached Figure Description

[0033] The invention and its advantages will be further understood by reading the following detailed description of some preferred exemplary embodiments with reference to the accompanying drawings:

[0034] Figure 1 A schematic cross-sectional side view of a pressure dome in the prior art is shown;

[0035] Figure 2 A schematic cross-sectional side view of a pressure dome in another prior art is shown;

[0036] Figure 3 A schematic front view of the pressure measuring device according to the present invention is shown;

[0037] Figure 4a A schematic top view of the main body of the pressure measuring device according to the present invention is shown;

[0038] Figure 4b Showing Figure 4a A cross-sectional side view of the main body of the medium pressure measuring device;

[0039] Figure 5a A schematic top view of the pressure measuring device according to this disclosure is shown;

[0040] Figure 5b Showing Figure 5a A cross-sectional side view of the medium pressure measuring device; and

[0041] Figure 6 A schematic front view of a pressure measuring device with a clamping assembly according to the present invention is shown. Detailed Implementation

[0042] To better understand the basic concepts of the present invention, some exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings.

[0043] For the sake of brevity, this document cites the disclosure of U.S. Patent 9,050,417, and identical or corresponding features marked with the same reference numerals shall not be repeated.

[0044] According to one aspect of the invention, a membrane for a pressure measuring device is first provided herein. Referring to the drawings, 10 generally represents a pressure measuring device, including a membrane 12. Those skilled in the art will appreciate that the pressure measuring device 10 can be manufactured in the form of a pressure dome, but is not limited to that design. Here, "interior" refers to the portion of the pressure measuring unit 10 occupied by physiological fluid during use. Therefore, with respect to the membrane 12, the inner surface 121 refers to the surface wetted by physiological fluid during use, while the outer surface 122 is the surface that contacts the pressure sensor.

[0045] like Figure 3 As shown, the diaphragm 12 for the pressure measuring device includes an elastic circular diaphragm 120 for closing one side of the pressure measuring device 10, thereby forming a gap between the interior and exterior of the pressure measuring device; wherein, through the peripheral portion of the diaphragm 12 away from the center, the elastic circular diaphragm 120 is horizontally fixed to the surface of the chamber of the pressure measuring device 10. It is obvious, as... Figure 4a and Figure 4b As shown, when there is no pressure difference between the pressures acting on the inner surface 121 and the outer surface 122 respectively, the elastic circular diaphragm 120 is flat.

[0046] According to an exemplary embodiment of the present invention, when there is no pressure difference between the pressures acting on the inner surface 121 and the outer surface 122 respectively, the elastic circular diaphragm 120 is a flat diaphragm.

[0047] and Figure 1 Compared to the diaphragm shown, the elastic circular diaphragm 120 of the present invention does not have a rigid polymer retaining ring for fixing the periphery of the membrane 12. Furthermore, the elastic circular diaphragm 120 also does not have any rings associated with fixing the periphery of the membrane 12. The manufacture of this membrane, particularly the elastic circular diaphragm, does not require a two-component injection molding operation, thereby reducing process complexity, making it easy to manufacture, and at a cost comparable to conventional molds.

[0048] like Figure 2 As shown, the cross-section of the circular flange 124 in the prior art is significantly thicker than the cross-section of the elastic circular diaphragm 120, for example, more than three times thicker than the diaphragm wall 120. The relative rigidity of the circular flange 124 is necessary for effectively and stably fixing the membrane 12 to the body 16 of the pressure dome 10. Figure 2 Compared to the diaphragm 120 shown, the elastic circular diaphragm 120 of the present invention does not have a circular flange for connecting to the body 16 of the pressure measuring device 10, which is evident from... Figure 5b As can be clearly seen, the elastic circular diaphragm 120 of membrane 12 is perfectly flat. In this way, the plane of the pressure sensor can ideally rest on the plane of the elastic circular diaphragm 120; thus enabling the pressure measuring device and the coupling sensor to couple more effectively and perform their functions more accurately.

[0049] According to an exemplary embodiment of the present invention, such as Figure 5a As shown, membrane 12 is preferably integrally molded. In other words, it is preferably injection molded from a single material. For example, membrane 12 of the present invention can be made of thermoplastic elastomer (TPE), preferably thermoplastic polyurethane (TPU), or other elastomers suitable for contact with physiological fluids. Membrane 12, in particular, the elastic circular diaphragm 120, is preferably made of polyvinyl chloride (PVC).

[0050] According to an exemplary embodiment of the present invention, the membrane 12 has a specific thickness to ensure its mechanical properties, such as... Figure 5a and 5b As shown, in particular, the thickness of the elastic circular diaphragm 120 is between 0.25 mm and 0.4 mm, preferably between 0.25 mm and 0.35 mm, and more preferably between 0.26 mm and 0.33 mm.

[0051] According to an exemplary embodiment of the present invention, the elastic circular diaphragm 120 is made of a membrane 12 with a Shore A hardness between 80A and 90A, preferably between 82A and 88A, and more preferably between 84A and 86A.

[0052] It will be apparent to those skilled in the art that the membrane 12 provided according to the present invention does not require two-component injection molding. Furthermore, the membrane does not require the fabrication of specialized molds for manufacturing and can be produced using simple and reliable techniques, while still ensuring the high quality and reliability associated with known types of pressure domes. Therefore, this membrane can be produced rapidly, thereby accelerating the manufacturing process.

[0053] According to another aspect of the invention, such as Figure 3 As shown, it provides a pressure measuring device 10 that cooperates with a pressure sensor 22. According to an exemplary embodiment, the pressure measuring device 10 includes a body 16 defining an inlet 160 and an outlet 161 adapted to allow liquid connection to a pipe, wherein the pressure measuring device 10 also includes a diaphragm 12 as described above, which fails to... Figure 3 The pressure measuring device is shown in the front view.

[0054] like Figure 4a and 4b As shown, the main body 16 of the pressure measuring device 10 has a protrusion 265 and a collar portion 266; it also includes a surface for horizontally mounting the membrane 12, and this surface area is located between the protrusion 265 and the collar portion 266. The main body 16 provided by the present invention obviously does not have a base 162 defining the membrane 12 by an edge portion 164 and / or an inner wall 165. As... Figure 2 The edge portion 164 shown is used to fix the membrane 12 inside the base 162 by rolling the edge, and these components and structures are obviously not included in the design provided by the present invention.

[0055] According to an exemplary embodiment of the present invention, such as Figure 5b As shown, the inner surface of the collar portion 266 has an extending inclined surface that extends from the upper edge or top of the collar portion 266 to the surface between the protrusion 265 and the collar portion 266. This design allows for a certain degree of horizontal movement when the pressure measuring unit is coupled to the pressure sensor, thereby facilitating easier and more reliable positioning between the two. Furthermore, the protrusion 265 may also have an extending inclined surface that extends from the top of the protrusion 265 to the surface between the protrusion 265 and the collar portion 266; this also facilitates self-positioning when coupled to the pressure sensor.

[0056] The cavity enclosed by the inner wall of the collar portion 266 is used to house the sensor. The vertical distance from the top of the collar 266 to the surface between the protrusion 265 and the collar portion 266, i.e., the depth of the cavity, depends primarily on the size of the pressure sensor. Those skilled in the art will understand that as the sensor becomes thinner, the depth of the cavity or the height of the collar portion 266 can be optimized accordingly to further reduce the amount of material used. Furthermore, reducing the overall size of the pressure measurement unit allows for more space to be made for other components on the extracorporeal blood circulation module (EBM).

[0057] According to an exemplary embodiment of the invention, the body 16 of the pressure measuring device 10 is manufactured by injection molding of a polymer that has sufficient rigidity and is suitable for contact with physiological fluids. Polymers suitable for this application are preferably polycarbonate (PC), rigid polyvinyl chloride (PVC), or methyl methacrylate acrylonitrile butadiene styrene (MABS).

[0058] like Figure 5a and 5b As shown, the outer periphery of the diaphragm 12 is disposed on the surface between the protrusion 265 and the collar portion 266, and then fixed to this surface by welding; that is, the elastic circular diaphragm 120 is welded to the surface of the chamber of the pressure measuring device 10. Therefore, as Figure 5a As shown, after the outer periphery of the membrane 12 is welded, the pressure measuring device 10 is sealed as a whole. Figure 5b As shown, the welding area 264 of the membrane 12 can be pressed and its periphery stretched and extended by a thermal welding module or similar means to keep it as flat as possible, thereby flattening the periphery of the membrane 12 after welding. Due to existing mature welding technology, flattening the welding area 264 is simple and easy, requiring no complex assembly machines.

[0059] According to an exemplary embodiment of the present invention, the height of the protrusion 265 relative to the welding area is approximately 0.7 mm, while... Figure 2 In the illustrated embodiment, the height of the inner wall 165 relative to the base 162 is approximately between 2.5 mm and 3 mm. Therefore, due to the flat membrane, body structure, and / or welding manufacturing process provided by the present invention, the protrusion 265 can be set much lower than / much smaller than the height of the inner wall 165. Furthermore, although the height of the collar portion 266 can be... Figure 2The second outer edge 166 in the exemplary embodiment has the same height, but because it adopts a relatively vertical structure instead of an arcuate structure, the collar portion 266 uses less material. Therefore, the exemplary embodiment of the present invention further reduces material usage and manufacturing costs in addition to the simplified manufacturing and assembly process described above. Those skilled in the art will recognize that the height of the collar portion, or even the entire height of the pressure measurement unit body, has a relatively small impact on test accuracy and reliability compared to the characteristics of the membrane disclosed herein; therefore, those skilled in the art can select appropriate collar portion height and / or pressure measurement unit body height to meet specific requirements in practical applications.

[0060] According to another exemplary embodiment of the invention, the pressure measuring device may further include a pressing member 267, which is configured to face the operator when the pressure measuring device is manually, automatically, or semi-automatically installed onto the machine. Figure 6 As shown, to facilitate the installation of the pressure measuring device 10, the pressing member 267 can be configured as an integral part of the main body 16 or a component separately assembled onto the main body 16. Furthermore, those skilled in the art will understand that the pressing member itself can also be one or more separate components, which can be mounted on the main body in known ways, such as by assembly, bonding, welding, or other suitable manufacturing processes. Therefore, the pressing assembly can be made of the same or different materials as the main body 16. Moreover, there are no particular limitations on the shape, thickness, or size of the pressing member, as long as it is suitable for pressing the pressure measuring unit. In this way, the pressure measuring device can be easily installed on the medical device with relatively low pressure during treatment preparation.

[0061] According to another aspect of the invention, an extracorporeal circulation tubing is further provided, including the aforementioned pressure measuring device for monitoring at least one blood pressure before or after the dialyzer. This extracorporeal circulation tubing can be a conduit or tubing used for dialysis treatment in HD, hemofiltration (HF), hemodiafiltration (HDF), and CRRT therapies.

[0062] Based on the above description, those skilled in the art can clearly see that, according to the present invention, the membrane 12 and the pressure measuring device 10 are at least partially able to overcome the disadvantages mentioned in the prior art and maintain the accuracy of pressure measurement.

[0063] While certain embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the invention. Those skilled in the art can modify and / or replace the elements with equivalents in relation to the above embodiments of the membrane, pressure measuring device, and extracorporeal circulation tubing without departing from the scope of the appended claims to meet specific requirements.

Claims

1. A diaphragm (12) for a pressure measuring device, comprising: An elastic circular diaphragm (120) is used to close one side of the pressure measuring device (10), thereby forming a gap between the inside and outside of the pressure measuring device; The elastic circular diaphragm (120) is horizontally fixed to the surface of the chamber of the pressure measuring device (10) via its peripheral portion away from the center. When there is no pressure difference between the pressures acting on the inner surface (121) and the outer surface (122) respectively, the elastic circular diaphragm (120) is flat.

2. The film (12) according to claim 1, wherein The elastic circular diaphragm (120) does not have a ring made of rigid polymer for fixing the periphery of the diaphragm (12); and / or The elastic circular diaphragm (120) is not associated with the ring used to fix the outer periphery of the diaphragm (12).

3. The film (12) according to claim 1 or 2, wherein The elastic circular diaphragm (120) does not have a circular flange for engaging with the body (16) of the pressure measuring device (10).

4. The film (12) according to any one of the preceding claims, wherein The membrane (12) is made of thermoplastic elastomer (TPE), preferably thermoplastic polyurethane (TPU).

5. The film (12) according to any one of the preceding claims, wherein The membrane (12) or the elastic circular membrane (120) is made of polyvinyl chloride (PVC).

6. The film (12) according to any one of the preceding claims, wherein The thickness of the membrane (12) or the elastic circular membrane (120) is between 0.25 mm and 0.4 mm.

7. The film (12) according to any one of the preceding claims, wherein The Shore A hardness of the membrane (12) or the elastic circular membrane (120) is between 80A and 90A.

8. The film (12) according to any one of the preceding claims, wherein The membrane (12) is welded to the surface of the chamber of the pressure measuring device (10).

9. A pressure measuring device (10) for cooperation with a pressure sensor (22), comprising a main body (16) defining an inlet (160) and an outlet (161) adapted to allow connection of a liquid to a pipe, wherein, The pressure measuring device (10) further includes the membrane (12) as described in any one of the preceding claims.

10. The pressure measuring device (10) according to claim 9, wherein The body (16) has a surface for horizontally placing the membrane (12), and The body (16) does not have a base (162) that defines the membrane (12) by the edge portion (164) and / or the inner wall (165).

11. The pressure measuring device (10) according to claim 9 or 10, wherein The body (16) is manufactured by injection molding a polymer that is sufficiently rigid and suitable for contact with physiological fluids.

12. The pressure measuring device (10) according to any one of claims 9 to 11, wherein The polymer is selected from the group consisting of polycarbonate (PC), rigid polyvinyl chloride (PVC), and methyl methacrylate acrylonitrile butadiene styrene (MABS).

13. The pressure measuring device (10) according to any one of claims 9 to 12, wherein The main body (16) includes a protrusion (265) and a collar (266); and The outer periphery of the membrane (12) is welded to the surface between the protrusion (265) and the collar (266).

14. The pressure measuring device (10) according to any one of claims 9 to 13, wherein, The outer periphery of the membrane (12) is flat after being welded.

15. The pressure measuring device (10) according to any one of claims 9 to 14, wherein, After the outer periphery of the membrane (12) is welded, the pressure measuring device (10) is sealed as a whole.

16. The pressure measuring device (10) according to any one of claims 9 to 15, wherein, The inner surface of the collar portion (266) has an inclined surface extending to the surface between the protrusion (265) and the collar portion (266).

17. The pressure measuring device (10) according to any one of claims 9 to 16, wherein, The protrusion (265) is much lower than the inner wall (165).

18. The pressure measuring device (10) according to any one of claims 9 to 17, wherein, The main body (16) further includes a pressing component (267) for facilitating the installation of the pressure measuring device (10).

19. The pressure measuring device (10) according to any one of claims 9 to 18, wherein, The pressing component (267) is either an integrally formed component of the main body (16) or a component separately assembled onto the main body (16).

20. An extracorporeal circulation line having a pressure measuring device (10) as described in any one of claims 9 to 19, wherein, The pressure measuring device (10) is used to monitor at least one blood pressure before or after the dialyzer.

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