Diaphragm pump, ventricular assist device and ventricular assist equipment

Abstract

The invention relates to the technical field of medical instruments, in particular to a diaphragm pump, a ventricular assist device and ventricular assist equipment. The compliance of the first flexible diaphragm in the diaphragm assembly of the diaphragm pump is larger than that of the second flexible diaphragm, the deformable degree of the first flexible diaphragm is larger than that of the second flexible diaphragm, and the first flexible diaphragm with high compliance can respond to the change of the volume of a blood cavity more quickly and has higher elasticity and lower hardness; the second flexible diaphragm can bear higher pressure of the medium cavity, the pressure bearing performance of the diaphragm assembly is guaranteed, the first flexible diaphragm and the second flexible diaphragm are matched, and the problems that an existing diaphragm is slow in response to the volume change of the blood cavity, and the volume change of the blood cavity cannot be affected are solved. And cells in a blood cavity are greatly damaged.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to a diaphragm pump, a ventricular assist device and a ventricular assist equipment. Background Art

[0002] Percutaneous Ventricular Assist Device (pVAD) can help the heart work, or temporarily replace the heart's work when the heart cannot work. The device is usually inserted into the body (femoral artery, etc.) through the skin (percutaneously), and then connected to the heart to help or take over the heart's pumping function, increase blood flow, enhance blood perfusion, and reduce myocardial oxygen consumption. It empties blood from the left ventricle and discharges it into the ascending aorta in sync with the cardiac cycle. It is usually used in emergency situations, such as intraoperative and postoperative short-term cardiac support for high-risk coronary artery intervention (PCI) patients and cardiogenic shock patients. Therefore, the design of pVAD needs to focus more on miniaturization, convenience and minimally invasiveness. Its biggest feature is small size, strong function, easy operation, and rapid intervention in a short time, allowing patients with acute heart failure to quickly establish blood circulation and win precious treatment time.

[0003] Percutaneous ventricular assist devices usually include a catheter, a diaphragm pump and a host, wherein the catheter is used to extend into the heart, and the chamber of the diaphragm pump is divided into a medium chamber and a blood chamber through a diaphragm, wherein the blood chamber is connected to the catheter inserted into the human body to receive the blood pumped by the heart, and the medium chamber is connected to the host to contain the fluid medium for pumping blood. When the heart is in the systolic phase, blood is input into the blood chamber of the diaphragm pump through the catheter, at which time the diaphragm deforms so that the blood occupies the blood chamber to the greatest extent, and there is almost no medium in the fluid medium chamber; when the heart is in the diastolic phase, the host controls the fluid medium to fill the medium chamber, at which time due to the continuous filling of the medium, the diaphragm gradually deforms in the opposite direction, thereby pushing the blood out of the diaphragm pump and flowing into the ascending aorta through the two-way valve at the proximal end of the catheter.

[0004] During the operation of the diaphragm pump, since the diaphragm needs to be able to withstand the pressure of the medium cavity, the current diaphragm has low compliance and responds slowly to the volume changes of the blood cavity, causing significant damage to the cells in the blood cavity. Summary of the invention

[0005] The present application provides a diaphragm pump for improving the problem that the current diaphragm has a slow response to the volume change of the blood cavity and the cells in the blood cavity are severely damaged.

[0006] In addition, the present application also provides a ventricular assist device and a ventricular assist equipment using the above-mentioned diaphragm pump.

[0007] In a first aspect, a diaphragm pump is provided in one embodiment, comprising: a pump housing having a chamber therein; and a diaphragm assembly, wherein the chamber is divided into a blood chamber and a medium chamber by the diaphragm assembly; the pump housing has a blood channel connected to the blood chamber, and the blood channel is used to allow blood to enter and exit the blood chamber; the pump housing also has a medium channel connected to the medium chamber, and the medium channel is used to allow fluid medium to enter and exit the medium chamber; the diaphragm assembly includes at least two layers of flexible diaphragms, wherein one layer of the flexible diaphragms is a first flexible diaphragm, and one layer of the flexible diaphragms is a second flexible diaphragm; one side of the first flexible diaphragm is exposed in the blood chamber, and one side of the second flexible diaphragm is exposed in the medium chamber; The compliance of the first flexible diaphragm is greater than the compliance of the second flexible diaphragm.

[0008] Furthermore, in one embodiment, the portion of the first flexible membrane in the chamber is the first portion, the portion of the second flexible membrane in the chamber is the second portion, and the area of ​​the first portion is smaller than the area of ​​the second portion.

[0009] Furthermore, in an embodiment, the range of the ratio a of the area of ​​the first portion to the area of ​​the second portion is: 0.7≤a<1.

[0010] Furthermore, in an embodiment, the range of the ratio a of the area of ​​the first portion to the area of ​​the second portion is: 0.85≤a<1.

[0011] Furthermore, in one embodiment, any adjacent flexible membranes are adsorbed together by vacuum.

[0012] Furthermore, in one embodiment, a lubricating medium is provided between any adjacent flexible membranes, or at least one of the adjacent flexible membranes has a lubricating coating, and at least one of the two opposite sides of the adjacent flexible membranes is a surface of the lubricating coating.

[0013] Furthermore, in one embodiment, the number of the flexible diaphragms is two, or the number of the flexible diaphragms is three or more, and the flexible diaphragm between the first flexible diaphragm and the second flexible diaphragm is an intermediate flexible diaphragm, and the compliance of the intermediate flexible diaphragm is less than or equal to the compliance of the first flexible diaphragm, and greater than or equal to the compliance of the second flexible diaphragm.

[0014] Furthermore, in one embodiment, the hardness of the first flexible diaphragm is in the range of 20-65HA, and the elastic modulus is in the range of 0.3-2.3Mpa, and / or the hardness of the second flexible diaphragm is in the range of 50-85HA, and the elastic modulus is in the range of 11-25Mpa.

[0015] In a second aspect, an embodiment provides a ventricular assist device, including a catheter and a diaphragm pump; Diaphragm pump, including: a pump housing having a chamber therein; and a diaphragm assembly, wherein the chamber is divided into a blood chamber and a medium chamber by the diaphragm assembly; the catheter is used to intervene in a human body and communicate with the blood chamber; the pump housing has a blood channel communicated with the blood chamber, and the blood channel is used to allow blood to enter and exit the blood chamber; the pump housing also has a medium channel communicated with the medium chamber, and the medium channel is used to allow fluid medium to enter and exit the medium chamber; the diaphragm assembly includes at least two layers of flexible diaphragms, wherein one layer of the flexible diaphragms is a first flexible diaphragm, and one layer of the flexible diaphragms is a second flexible diaphragm; one side of the first flexible diaphragm is exposed in the blood chamber, and one side of the second flexible diaphragm is exposed in the medium chamber; The compliance of the first flexible diaphragm is greater than the compliance of the second flexible diaphragm.

[0016] Furthermore, in one embodiment, the portion of the first flexible membrane in the chamber is the first portion, the portion of the second flexible membrane in the chamber is the second portion, and the area of ​​the first portion is smaller than the area of ​​the second portion.

[0017] Furthermore, in an embodiment, the range of the ratio a of the area of ​​the first portion to the area of ​​the second portion is: 0.7≤a<1.

[0018] Furthermore, in an embodiment, the range of the ratio a of the area of ​​the first portion to the area of ​​the second portion is: 0.85≤a<1.

[0019] Furthermore, in one embodiment, any adjacent flexible membranes are adsorbed together by vacuum.

[0020] Furthermore, in one embodiment, a lubricating medium is provided between any adjacent flexible membranes, or at least one of the adjacent flexible membranes has a lubricating coating, and at least one of the two opposite sides of the adjacent flexible membranes is a surface of the lubricating coating.

[0021] Furthermore, in one embodiment, the number of the flexible diaphragms is two, or the number of the flexible diaphragms is three or more, and the flexible diaphragm between the first flexible diaphragm and the second flexible diaphragm is an intermediate flexible diaphragm, and the compliance of the intermediate flexible diaphragm is less than or equal to the compliance of the first flexible diaphragm, and greater than or equal to the compliance of the second flexible diaphragm.

[0022] Furthermore, in one embodiment, the hardness of the first flexible diaphragm is in the range of 20-65HA, and the elastic modulus is in the range of 0.3-2.3Mpa, and / or the hardness of the second flexible diaphragm is in the range of 50-85HA, and the elastic modulus is in the range of 11-25Mpa.

[0023] In a third aspect, an embodiment provides a ventricular assist device, including a pumping host and a ventricular assist device; Ventricular assist devices include catheters and diaphragm pumps; Diaphragm pumps include: a pump housing having a chamber therein; and a diaphragm assembly, wherein the chamber is divided into a blood chamber and a medium chamber by the diaphragm assembly; the catheter is used to intervene in the human body and communicate with the blood chamber; the pumping host is communicated with the medium chamber to pump or extract fluid medium into the medium chamber; the pumping host includes a pressure sensor for detecting the pressure in the medium chamber; the pump housing has a blood channel communicated with the blood chamber, and the blood channel is used to allow blood to enter and exit the blood chamber; the pump housing also has a medium channel communicated with the medium chamber, and the medium channel is used to allow fluid medium to enter and exit the medium chamber; the diaphragm assembly includes at least two layers of flexible diaphragms, one of which is a first flexible diaphragm and the other is a second flexible diaphragm; one side of the first flexible diaphragm is exposed in the blood chamber, and one side of the second flexible diaphragm is exposed in the medium chamber; The compliance of the first flexible diaphragm is greater than the compliance of the second flexible diaphragm.

[0024] Furthermore, in one embodiment, the portion of the first flexible membrane in the chamber is the first portion, the portion of the second flexible membrane in the chamber is the second portion, and the area of ​​the first portion is smaller than the area of ​​the second portion.

[0025] Furthermore, in an embodiment, the range of the ratio a of the area of ​​the first portion to the area of ​​the second portion is: 0.7≤a<1.

[0026] Furthermore, in an embodiment, the range of the ratio a of the area of ​​the first portion to the area of ​​the second portion is: 0.85≤a<1.

[0027] Furthermore, in one embodiment, any adjacent flexible membranes are adsorbed together by vacuum.

[0028] Furthermore, in one embodiment, a lubricating medium is provided between any adjacent flexible membranes, or at least one of the adjacent flexible membranes has a lubricating coating, and at least one of the two opposite sides of the adjacent flexible membranes is a surface of the lubricating coating.

[0029] Furthermore, in one embodiment, the number of the flexible diaphragms is two, or the number of the flexible diaphragms is three or more, and the flexible diaphragm between the first flexible diaphragm and the second flexible diaphragm is an intermediate flexible diaphragm, and the compliance of the intermediate flexible diaphragm is less than or equal to the compliance of the first flexible diaphragm, and greater than or equal to the compliance of the second flexible diaphragm.

[0030] Furthermore, in one embodiment, the hardness of the first flexible diaphragm is in the range of 20-65HA, and the elastic modulus is in the range of 0.3-2.3Mpa, and / or the hardness of the second flexible diaphragm is in the range of 50-85HA, and the elastic modulus is in the range of 11-25Mpa.

[0031] According to the diaphragm pump of the above embodiment, since the compliance of the first flexible diaphragm in the diaphragm assembly of the diaphragm pump in the present application is greater than the compliance of the second flexible diaphragm, the second flexible diaphragm can withstand a higher pressure in the medium cavity, ensuring the pressure-bearing performance of the diaphragm assembly, the first flexible diaphragm is more deformable than the second flexible diaphragm, and the first flexible diaphragm with high compliance can respond faster to changes in the volume of the blood cavity, improving the problem of the current diaphragm responding slowly to changes in the volume of the blood cavity. Since the first flexible diaphragm with high compliance has higher elasticity and lower hardness, it has better compatibility with blood, can reduce damage to blood cells, and improve the problem of severe damage to cells in the blood cavity.

[0032] Furthermore, the area of ​​the first part is smaller than that of the second part, which increases the area of ​​the second flexible diaphragm in the chamber, so that the second flexible diaphragm can better cooperate with the first flexible diaphragm to quickly respond to changes in the volume of the blood chamber under given physical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram of the structure of a ventricular assist device in an embodiment; Figure 2 A schematic diagram of the structure of a diaphragm pump in an embodiment; Figure 3 is a cross-sectional view of a diaphragm pump in one embodiment; Figure 4 A cross-sectional view of a diaphragm pump when the heart is in systole in one embodiment.

[0034] List of feature names corresponding to the figure marks in the figure: 1. Pumping main unit; 2. Catheter; 21. Window; 22. Two-way valve; 3. Diaphragm pump; 31. Pump housing; 311. First shell; 312. Second shell; 313. Catheter connector; 314. Fluid medium connector; 32. Diaphragm assembly; 321. First flexible diaphragm; 3211. First part; 3212. First clamping part; 322. Second flexible diaphragm; 3221. Second part; 3222. Second clamping part; 33. Chamber; 331. Blood chamber; 332. Medium chamber; 34. Blood channel; 35. Medium channel. DETAILED DESCRIPTION

[0035] The present application is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are intended to enable the present application to be better understood. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, and methods. In some cases, some operations related to the present application are not shown or described in the specification, in order to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0036] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0037] In the description of this document, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features.

[0039] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, abutment, or indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0041] The various embodiments described in the specific implementation manner can be combined in any suitable manner without contradiction. For example, different implementation manners can be formed by combining different embodiments. In order to avoid unnecessary repetition, various possible combinations of the embodiments will not be described separately.

[0042] The diaphragm pump is divided into two chambers by a flexible diaphragm. The two chambers contain two fluids of different properties, blood and fluid medium. Since blood contains blood cells, proteins, inorganic salts and other substances, which have different densities from the fluid medium, the response to the same pressure is also different. Therefore, the traditional flexible diaphragm of a single material is difficult to meet the physical properties of two different fluids. The diaphragm pump only plays the role of transit pumping. The blood entering the blood chamber of the diaphragm pump still needs to return to the patient's body. Therefore, the flexible diaphragm in the diaphragm pump, as a structure that applies pressure to the blood, needs to consider the biocompatibility of the material and minimize damage to easily damaged substances such as blood cells in the blood.

[0043] In view of the fact that the flexible diaphragm in the diaphragm pump must withstand a large pressure from the fluid medium while reducing the need for damage to blood cells, the present application provides a diaphragm assembly comprising at least two layers of flexible diaphragms. The first flexible diaphragm and the second flexible diaphragm in the diaphragm assembly are made of materials with different compliances, so that the first flexible diaphragm is more adaptable to the blood cavity and the second flexible diaphragm is more adaptable to the medium cavity. In this way, the first flexible diaphragm can respond to changes in the blood cavity in a timely manner and reduce damage to blood cells, and the second flexible diaphragm can withstand a large pressure, thereby ensuring the pressure-bearing performance of the diaphragm assembly.

[0044] The ventricular assist device, assist apparatus and diaphragm pump in the present application are described in detail below in conjunction with the accompanying drawings.

[0045] For some examples, please refer to Figures 1 to 4 The ventricular assist device includes a pumping main unit 1 and a ventricular assist device. The ventricular assist device includes a catheter 2 and a diaphragm pump 3. The diaphragm pump 3 includes a pump housing 31 and a diaphragm assembly 32. The pump housing 31 has a chamber 33, and the chamber 33 is divided into a blood chamber 331 and a medium chamber 332 by the diaphragm assembly 32. The catheter 2 is used to intervene in the human body and communicate with the blood chamber 331. The pump housing 31 has a blood channel 34 communicated with the blood chamber 331. The blood channel 34 is used to communicate with the catheter 2 so that blood can enter and exit the blood chamber 331. The pump housing 31 also has a medium channel 35 communicated with the medium chamber 332. The medium chamber 332 is used to communicate with the pumping main unit 1 through the medium channel 35, so that the fluid medium can enter the medium chamber 332 through the medium channel 35. The pumping main unit 1 can both fill the medium chamber 332 with fluid medium and extract the fluid medium from the medium chamber 332.

[0046] During the systole of the heart, the blood chamber 331 can receive the blood pumped out by the heart through the blood channel 34, and the fluid medium in the medium chamber 332 flows out through the medium channel 35. During the diastole of the heart, the pumping host 1 controls the fluid medium to fill the medium chamber 332. Due to the continuous filling of the fluid medium, the diaphragm assembly 32 deforms toward the blood chamber 331, pushing the blood in the blood chamber 331 out of the diaphragm pump 3 and flowing into the ascending aorta through the catheter 2.

[0047] Regarding the structure of the diaphragm assembly 32, the diaphragm assembly 32 includes at least two layers of flexible diaphragms, one of which is a first flexible diaphragm 321 and the other is a second flexible diaphragm 322; one side of the first flexible diaphragm 321 is exposed in the blood cavity 331 and can contact blood. One side of the second flexible diaphragm 322 is exposed in the medium cavity 332 and can contact the fluid medium. The compliance of the first flexible diaphragm 321 is greater than the compliance of the second flexible diaphragm 322, and the second flexible diaphragm 322 can withstand a higher pressure in the medium cavity 332, thereby ensuring the pressure-bearing performance of the diaphragm assembly 32. The first flexible diaphragm 321 is more deformable than the second flexible diaphragm 322, and the first flexible diaphragm 321 with high compliance can respond to the volume change of the blood cavity 331 more quickly, thereby improving the problem that the current diaphragm responds slowly to the volume change of the blood cavity 331. Since the first flexible diaphragm 321 with high compliance has higher elasticity and lower hardness, it has better compatibility with blood and reduces damage to blood cells. In addition, the two or more layers of flexible diaphragms in the present application can also reduce the impact caused by diaphragm rupture. When one layer of the flexible diaphragm is damaged and ruptured, the other layers of the flexible diaphragms can prevent the fluid in the medium cavity 332 from entering the blood cavity 331, thereby avoiding secondary damage to the patient. In this way, the present application not only solves the unacceptable clinical risks caused by diaphragm damage, but also improves the problem of the slow response of the diaphragm to the volume change of the blood cavity.

[0048] In some embodiments, the pumping main unit 1 includes a pressure sensor (not shown in the figure), which can detect the pressure in the medium cavity 332. Specifically, the pressure sensor is an air pressure sensor integrated in the pumping main unit 1, located at the front end of the air path output interface in the pumping main unit 1, and can detect the air pressure of the air path connected to the medium cavity 332 and the medium cavity 332. When the medium cavity 332 needs to be filled with medium, the air pressure sensor measures a positive pressure value, and when the medium in the medium cavity 332 needs to be discharged, the air pressure sensor measures a negative pressure value. Therefore, since the pressure sensor can sense the pressure of the medium cavity 332, when one layer of the flexible diaphragm ruptures, an instantaneous pressure change will occur, and during the operation of the remaining flexible diaphragms, the driving force of the pumping main unit 1 on the diaphragm assembly 32 will also change. Based on the change in pressure, the pumping main unit 1 will urgently issue a high-level alarm, which can remind the operator to stop the operation of the membrane pump and replace the membrane pump.

[0049] Specifically, in some embodiments, the material of the flexible membrane can be silicone, such as PDMS, or rubber, such as TPU and TPE. Depending on the process, the compliance of the flexible membrane can be changed to meet the compliance requirements of the flexible membrane.

[0050] For some examples, please refer to Figure 3 and Figure 4In order to make the second flexible diaphragm 322 better adapt to the compliance of the first flexible diaphragm 321, the part of the first flexible diaphragm 321 in the chamber 33 is the first part 3211, and the part of the second flexible diaphragm 322 in the chamber 33 is the second part 3221. The area of ​​the first part 3211 is smaller than the area of ​​the second part 3221. Due to the insufficient elasticity of the second flexible diaphragm 322, under the condition of the same area and the same force, the deformation that can occur is smaller than that of the first flexible diaphragm 321. Compared with the first part 3211 and the second part 3221 having the same area, the area of ​​the first part 3211 is smaller than the area of ​​the second part 3221, which makes it easier to reduce or even eliminate the residual blood in the blood cavity 331 when pushing blood, and it is also easier to make the blood fill the entire cavity 33 when blood flows into the blood cavity 331. In addition, during the cardiac diastole, the second flexible diaphragm 322 in contact with the fluid medium has a lower compliance but a higher hardness and a stronger pressure resistance, and can withstand a relatively higher pressure in the medium cavity 332 , thereby increasing the service life of the diaphragm pump 3 .

[0051] Since the diaphragm assembly 32 needs to change its shape back and forth in the two cavities with the heart rate cycle, when the first part 3211 and the second part 3221 have the same area, the second flexible diaphragm 322 needs to deform more to match the deformation of the first flexible diaphragm 321. The second flexible diaphragm 322 will be more prone to fatigue and damage during the continuous back and forth pulling, which increases the risk of using the diaphragm pump 3. This problem can be improved by making the area of ​​the second part 3221 larger than the area of ​​the first part 3211, which can reduce the deformation of the second flexible diaphragm 322 and make it less likely to be damaged.

[0052] It should be noted that the portion of the first flexible diaphragm 321 located in the chamber 33, i.e., the first portion 3211, refers to the portion separating the chamber 33, and the portion used to mount the first flexible diaphragm 321 on the pump housing 31 (such as the first clamping portion 3212 bonded to or clamped on the pump housing 31) should not belong to the first portion 3211. Similarly, the portion of the second flexible diaphragm 322 located in the chamber 33, i.e., the second portion 3221, refers to the portion separating the chamber 33, and the portion used to mount the second flexible diaphragm 322 on the pump housing 31 (such as the second clamping portion 3222 bonded to or clamped on the pump housing) should not belong to the second portion 3221.

[0053] Regarding the area ratio of the first portion 3211 to the second portion 3221, in some embodiments, the range of the area ratio a of the first portion 3211 to the second portion 3221 is: 0.7≤a<1. Further, in some embodiments, the range of the area ratio a of the first portion 3211 to the second portion 3221 is: 0.85≤a<1. Specifically, the value of a can be 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, etc. Of course, in some other embodiments, the value of a can also be 1, that is, the area of ​​the first portion is equal to the area of ​​the second portion.

[0054] In order to make the diaphragm assembly 32 operate more stably, in some embodiments, any adjacent flexible diaphragms are adsorbed together by vacuum. By removing the air between two adjacent flexible diaphragms, a vacuum state is formed between the adjacent flexible diaphragms. Under the action of external pressure, when the diaphragm assembly 32 is in operation, the two adjacent flexible diaphragms can still be tightly attached together and will not separate due to push-pull movement.

[0055] In some embodiments, since the area of ​​the second portion 3221 is larger than the area of ​​the first portion 3211, after the vacuum is drawn between the second portion 3221 and the first portion 3211, the second portion 3221 and the first portion 3211 present different states based on the compliance difference between the second portion 3221 and the first portion 3211: For example, in some embodiments, when the compliance difference between the second part 3221 and the first part 3211 is large, that is, the second part 3221 is harder and the first part 3211 is softer, the first part 3211 is deformed by pressing against the second part 3221 and is recessed into the medium cavity 332 or the blood cavity 331 together with the second part 3221.

[0056] For another example, in one embodiment, when the difference in compliance between the second part 3221 and the first part 3211 is small, and the area of ​​the second part 3221 is relatively large compared to the first part 3211, the second part 3221 is slightly harder than the medium compliance, and the first part 3211 is slightly softer than the medium compliance, the second part 3221 may be wrinkled. In some embodiments, in order to reduce the friction between adjacent flexible membranes and avoid damage caused by relative sliding of adjacent flexible membranes, lubrication is performed between adjacent flexible membranes. Specific treatment methods include: in some embodiments, a lubricating medium (not shown in the figure) is provided between any adjacent flexible membranes, and the specific lubricating medium may be physiological saline or glucose solution (about 5%). In some other embodiments, at least one of the adjacent flexible membranes has a lubricating coating, and at least one of the two opposite sides of the adjacent flexible membranes is the surface of the lubricating coating. Specifically, the lubricating coating may be a silicone oil coating, a hydrophilic coating: PVP (polyvinyl pyrrolidone), a zwitterionic polymer (sulfobetaine SBMA, carboxymethyl chitosan CMC). Lubrication can reduce the friction between diaphragms and the risk of diaphragm rupture.

[0057] Regarding the number of flexible diaphragms in the diaphragm assembly 32, in one embodiment, the number of flexible diaphragms is two. Such a diaphragm assembly 32 has a simple structure.

[0058] In one embodiment, when the number of flexible membranes is more than three, the flexible membrane between the first flexible membrane 321 and the second flexible membrane 322 is an intermediate flexible membrane, and the compliance of the intermediate flexible membrane is less than or equal to the compliance of the first flexible membrane 321, and greater than or equal to the compliance of the second flexible membrane 322. The number of intermediate flexible membranes can be one or more. For example, in some embodiments, the number of flexible membranes is three, the number of intermediate flexible membranes is one, and the compliance of the intermediate flexible membrane can be less than the compliance of the first flexible membrane 321 and greater than the compliance of the second flexible membrane 322. Of course, the compliance of the intermediate flexible membrane can also be equal to the compliance of the first flexible membrane 321, and can also be equal to the compliance of the second flexible membrane 322. Of course, in addition to the number of flexible membranes being three, it can also be four, five, six or seven as needed.

[0059] The first flexible diaphragm 321 and the second flexible diaphragm 322 are respectively made of two materials with different compliances. In some embodiments, the compliance can be specified by two values: Shore A hardness and elastic modulus. Shore A is used to describe the hardness of softer materials. The larger the value, the greater the hardness. The elastic modulus is used to describe the stress of a material under unidirectional stress divided by the deformation in that direction. The larger the value, the greater the rigidity of the material. In some embodiments, the hardness of the first flexible diaphragm 321 ranges from 20-65HA and the elastic modulus ranges from 0.3-2.3Mpa. In some embodiments, the hardness of the second flexible diaphragm 322 ranges from 50-85HA and the elastic modulus ranges from 11-25Mpa.

[0060] Regarding the structure of the pump housing 31, in some embodiments, please refer to Figures 1 to 4 The pump housing 31 includes a first housing 311 and a second housing 312. The first housing 311 and the second housing 312 are joined to form a cavity, and the diaphragm assembly 32 is clamped between the first housing 311 and the second housing 312. The first clamping portion 3212 of the first flexible diaphragm 321 and the second clamping portion 3222 of the second flexible diaphragm 322 are clamped between the first housing 311 and the second housing 312. Specifically, in some embodiments, the pump housing 31 is a semicircular transparent housing.

[0061] For some examples, please refer to Figures 1 to 4 The pump housing 31 includes a catheter connector 313 and a fluid medium connector 314 , the medium channel 35 is located in the fluid medium connector 314 , the blood channel 34 is located in the catheter connector 313 , and the catheter 2 is connected to the catheter connector 313 .

[0062] Regarding the structure of the catheter 2, in some embodiments, please refer to Figure 1 A window 21 is provided at the front end of the catheter 2, and a two-way valve 22 is provided at the rear side of the window 21. The two-way valve 22 is used to open only when the diaphragm pump 3 pushes blood into the catheter 2, thereby establishing a passage between the inside of the catheter 2 and the ascending aorta.

[0063] For some examples, please refer to Figures 1 to 4 The operating steps of a ventricular assist device are: For patients who need ventricular assist, the femoral artery is punctured and the catheter 2 with a two-way valve 22 is guided into the patient's aorta by a guide wire. The front end window 21 of the catheter 2 is located in the left ventricle, and the two-way valve section is located in the ascending aorta outside the heart. When the blood fills the catheter 2, the catheter 2, the external diaphragm pump 3 and the external pumping host 1 are connected, and the pumping host 1 pushes the fluid medium in accordance with the heart rate, thereby pumping blood.

[0064] Specifically, during the systole of the heart, the pumping host 1 draws the medium in the medium cavity 332, and the blood in the heart enters the catheter 2 through the opening window at the front end of the catheter 2, and enters the blood cavity 331 of the diaphragm pump 3. Under the negative pressure of the medium cavity 332, the diaphragm assembly 32 deforms toward the medium cavity 332. During the diastole of the heart, the pumping host 1 pumps the medium into the medium cavity 332 of the diaphragm pump 3. At this time, the fluid medium (which can be liquid or gas) gradually fills the medium cavity 332, and the diaphragm assembly 32 is also pushed to deform, pushing the blood in the blood cavity 331 into the catheter 2, and the pushed blood flows into the ascending aorta from the two-way valve 22. The diaphragm pump 3 pumps back and forth once for each heart beat. The pumping host 1 controls the pushing of the medium according to the heart beat frequency of different patients, thereby realizing the function of assisting the ventricle to pump blood.

[0065] In this process, the first flexible diaphragm 321 with higher compliance contacts the blood, and the second flexible diaphragm 322 with lower compliance contacts the fluid medium. Since the area of ​​the second part 3221 is larger than the area of ​​the first part 3211, the first flexible diaphragm 321 and the second flexible diaphragm 322 are vacuumed, so when the diaphragm pump 3 is not running, the first flexible diaphragm 321 and the second flexible diaphragm 322 are tightly attached together. During the cardiac systole, the first flexible diaphragm 321 in contact with the blood can respond to the change in the volume of the blood cavity 331 more quickly and deform more quickly because of its higher compliance; while the second flexible diaphragm 322 has a lower compliance, that is, a higher hardness, so it has a stronger pressure resistance. Although the second flexible diaphragm 322 has a lower deformation capacity, because the area of ​​the second part 3221 on the second flexible diaphragm 322 is larger, it can satisfy the blood filling into the entire diaphragm pump 3. During the diastole period, the second flexible diaphragm 322 can withstand a relatively higher pressure in the medium chamber 332 due to its lower compliance but higher hardness, thereby increasing the service life of the diaphragm pump 3 and reducing the risk of diaphragm damage.

[0066] The above specific examples are used to illustrate the present application, which is only used to help understand the present application and is not intended to limit the present application. For technicians in the technical field to which the present application belongs, they can also make some simple deductions, deformations or substitutions based on the ideas of the present application.

Claims

1. A diaphragm pump, characterized in that: include: a pump housing having a chamber therein; and a diaphragm assembly, wherein the chamber is divided into a blood chamber and a medium chamber by the diaphragm assembly; The pump housing has a blood channel communicating with the blood chamber, and the blood channel is used to allow blood to enter and exit the blood chamber; The pump housing also has a medium channel connected to the medium cavity, and the medium channel is used to allow the fluid medium to enter and exit the medium cavity; The diaphragm assembly comprises at least two layers of flexible diaphragms, one of which is a first flexible diaphragm and the other is a second flexible diaphragm; one side of the first flexible diaphragm is exposed in the blood cavity, and one side of the second flexible diaphragm is exposed in the medium cavity; The compliance of the first flexible diaphragm is greater than the compliance of the second flexible diaphragm.

2. The diaphragm pump according to claim 1, characterized in that The portion of the first flexible membrane in the chamber is a first portion, and the portion of the second flexible membrane in the chamber is a second portion. An area of ​​the first portion is smaller than an area of ​​the second portion.

3. The diaphragm pump according to claim 2, characterized in that The range of the ratio a of the area of ​​the first part to the area of ​​the second part is: 0.7≤a<1.

4. The diaphragm pump according to claim 3, characterized in that: The range of the ratio a of the area of ​​the first part to the area of ​​the second part is: 0.85≤a<1.

5. The diaphragm pump according to claim 1, characterized in that: Any adjacent flexible membranes are adsorbed together by vacuum.

6. The diaphragm pump according to any one of claims 1 to 5, characterized in that: A lubricating medium is provided between any adjacent flexible membranes, or at least one of the adjacent flexible membranes has a lubricating coating, and at least one of the two opposite side surfaces of the adjacent flexible membranes is a surface of the lubricating coating.

7. The diaphragm pump according to any one of claims 1 to 5, characterized in that: The number of the flexible diaphragms is two, or the number of the flexible diaphragms is three or more, and the flexible diaphragm between the first flexible diaphragm and the second flexible diaphragm is an intermediate flexible diaphragm, and the compliance of the intermediate flexible diaphragm is less than or equal to the compliance of the first flexible diaphragm, and greater than or equal to the compliance of the second flexible diaphragm.

8. The diaphragm pump according to any one of claims 1 to 5, characterized in that: The first flexible membrane has a hardness ranging from 20-65 HA and an elastic modulus ranging from 0.3-2.3 MPa, and / or the second flexible membrane has a hardness ranging from 50-85 HA and an elastic modulus ranging from 11-25 MPa.

9. A ventricular assist device, characterized in that: It comprises a catheter and a diaphragm pump as described in any one of claims 1 to 8; the catheter is used for intervention in the human body and is connected with the blood cavity.

10. A ventricular assist device, characterized in that: It comprises a pumping host and a ventricular assist device as described in claim 9; the pumping host is connected to the medium chamber to pump or extract fluid medium into the medium chamber; the pumping host comprises a pressure sensor for detecting the pressure in the medium chamber.

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