A centrifugal heart pump with low hemolysis rate

Abstract

The invention discloses a low hemolysis rate centrifugal heart pump, comprising: a front pump cover, a rear pump cover, an impeller, an inlet pipeline and an outlet pipeline; the front pump cover and the rear pump cover are combined to form a spiral volute extrusion chamber; a spiral flow channel is arranged in the volute extrusion chamber, the inlet pipeline is arranged on the surface of the front pump cover and connected to the volute extrusion chamber, the outlet pipeline is arranged on the side of the rear pump cover and connected to the volute extrusion chamber, and an impeller is arranged in the volute extrusion chamber; a bearing is arranged at the center of the rear pump cover, the shape of the rear pump cover can accommodate the entire impeller, the center of the impeller is connected to the bearing, and the bearing is used to support the impeller to rotate around the bearing. The advantages of the invention are: the stress on the blood inside the pump body is reduced; it is conducive to reducing the vortex flow state similar to the Karman vortex generated by the blood flowing through, so that the flow in the pump body is more uniform; the processing procedures are more simplified, and the processing time of a single product is shortened.

Description

Technical Field

[0001] The invention relates to the technical field of medical devices, and in particular to a low hemolysis rate centrifugal heart pump. Background Art

[0002] Heart failure has been listed as the number one killer of humans, along with cancer. There are more than 10 million heart failure patients in my country, and the prevalence of heart failure is even higher in developed countries. The annual cost of treating heart failure in the United States is as high as 30.7 billion US dollars. For a considerable number of patients, other medical measures such as drugs are ineffective and they are on the verge of death. Heart transplantation or an extracorporeal heart to maintain life characteristics while waiting for the body heart or transplanted heart to gradually recover is the most effective method for treating patients with related heart diseases and major diseases, and is an important achievement and breakthrough made by humans in the process of treating heart disease.

[0003] Internationally, the United States, Japan, Australia and other countries have mature technologies, completed clinical trials, and passed FDA certification for extracorporeal heart pump devices, which have been promoted and applied in major medical centers around the world. In China, the relevant technology is still in the research and development stage, and the prices of mature foreign products entering the Chinese market are relatively high, which puts a huge economic burden on providing necessary services to the vast number of Chinese patients, which directly leads to the lack of extracorporeal heart pump products in China.

[0004] Biomedicine and high-performance medical devices are one of the ten major areas advocated by the State Council in "Made in China 2025". Although extracorporeal heart pumps are widely used in major heart centers abroad, their potential problems cannot be underestimated. Because the unnatural physiological flow state inside them will lead to local high shear stress in the flow channel, which will then cause complications such as hemolysis, thrombosis, and secondary flow immunosuppression. Summary of the invention

[0005] The present invention aims at the defects of the prior art and provides a centrifugal heart pump with low hemolysis rate, thereby solving the defects of the prior art.

[0006] In order to achieve the above invention object, the technical solution adopted by the present invention is as follows:

[0007] A low hemolysis rate centrifugal heart pump comprises: a front pump cover, a rear pump cover, an impeller, an inlet pipeline and an outlet pipeline;

[0008] The front pump cover and the rear pump cover are combined to form a spiral volute extrusion chamber; a spiral flow channel is provided in the volute extrusion chamber, an inlet pipeline is arranged on the surface of the front pump cover and connected to the volute extrusion chamber, an outlet pipeline is arranged on the side of the rear pump cover and connected to the volute extrusion chamber, and an impeller is arranged in the volute extrusion chamber; a bearing is provided in the center of the rear pump cover, the shape of the rear pump cover can accommodate the entire impeller, the center of the impeller is connected to the bearing, and the bearing is used to support the impeller to rotate around the bearing.

[0009] The impeller is a semi-open impeller, which consists of an impeller rear cover, a magnetic drive seat, blades, and a shaft support frame.

[0010] The magnetic drive seat is in a circular shape, and the inner and outer ring edges of the magnetic drive seat are respectively provided with an outer wall and an inner wall, and a plurality of slots are evenly arranged on the inner side of the outer wall around the outer ring, and magnetic blocks are installed in the slots; the inner surface of the inner wall is fixed with an axle support frame.

[0011] A hemispherical groove is provided at the center of the shaft support frame, and the top of the bearing is a spherical protrusion; the spherical protrusion is inserted into the groove to form a rotation feature; or a spherical protrusion is provided at the center of the shaft support frame, and the top of the bearing is a hemispherical groove; the spherical protrusion is inserted into the groove to form a rotation feature.

[0012] The shaft support frame is composed of three support legs, which divide the inner circle of the magnetic drive seat into three equal parts.

[0013] The impeller rear cover is in a circular shape, and four blades are evenly arranged on the surface of the impeller rear cover. The outer ring of the impeller rear cover matches the outer wall of the magnetic drive seat, and the inner ring matches the inner wall of the magnetic drive seat. The impeller rear cover is used to cover the magnetic drive seat and seal to prevent blood from entering the magnetic drive seat.

[0014] Furthermore, the cross section of the support leg is an airfoil shape, which is beneficial for the blood flow from the impeller rear cover plate to generate as few vortex flows as possible after flowing through the support leg.

[0015] Furthermore, the flow rate of the centrifugal heart pump is 2-6 L / min; the head at the design operating point is 1.63 mH2O.

[0016] Furthermore, the inlet pipe is of a gradually expanding type with an expansion angle of 7 degrees, an inlet diameter of the inlet pipe is 22 mm, and an outlet diameter of the outlet pipe is 17 mm.

[0017] Furthermore, the heart pump has an inlet velocity of 0.405 m / s and an outlet velocity of 0.679 m / s.

[0018] Furthermore, the impeller inlet equivalent diameter is 17 mm, the inlet diameter is 20 mm, the impeller outer diameter is 50 mm; the impeller outlet width is 3 mm.

[0019] Furthermore, the blade outlet angle is 29 degrees; and the blade inlet angle is 34 degrees.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] The stress on the blood cells inside the pump body is reduced; the radial cross-section of the support legs of the impeller shaft support frame is an airfoil, which is beneficial to reduce the vortex flow state similar to the Karman vortex generated by the blood flowing through, making the flow in the pump body more uniform; due to the semi-open impeller, the processing process is simplified and the processing time of a single product is shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of a heart pump according to Embodiment 1 of the present invention;

[0023] Figure 2 is a schematic diagram of the structure of the heart pump in Example 1 of the present invention without the front pump cover and the inlet pipeline;

[0024] Figure 3 is a schematic structural diagram of a rear pump cover according to Embodiment 1 of the present invention;

[0025] Figure 4 is a schematic structural diagram of an impeller in Embodiment 1 of the present invention;

[0026] Figure 5 It is a schematic diagram of the assembly of the rear pump cover and the magnetic drive seat of Example 1 of the present invention;

[0027] Figure 6 1 is a schematic diagram of a supporting frame structure with a groove in the center of Embodiment 1 of the present invention;

[0028] Figure 7 is a schematic diagram of the bearing structure with spherical protrusions according to embodiment 1 of the present invention;

[0029] Figure 8 is a schematic diagram of the support frame structure with spherical protrusions according to embodiment 2 of the present invention;

[0030] Fig. 9 It is a schematic diagram of the bearing structure with grooves according to embodiment 2 of the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples.

[0032] Example 1

[0033] like Figures 1 to 3 As shown, a low hemolysis rate centrifugal heart pump comprises: a front pump cover 1, a rear pump cover 2, an impeller 3, an inlet pipeline 4 and an outlet pipeline 5;

[0034] The front pump cover 1 and the rear pump cover 2 are combined to form a spiral volute extrusion chamber; a spiral flow channel is provided in the volute extrusion chamber, an inlet pipeline 4 is arranged on the surface of the front pump cover 1 and connected to the volute extrusion chamber, an outlet pipeline 5 is arranged on the side of the rear pump cover 2 and connected to the volute extrusion chamber, and an impeller 3 is arranged in the volute extrusion chamber; a bearing 6 is provided at the center of the rear pump cover 2, and the shape of the rear pump cover 2 can accommodate the entire impeller 3, the center of the impeller 3 is connected to the bearing 6, and the bearing 6 is used to support the impeller 3 to rotate around the bearing 6.

[0035] like Figure 4 and5 As shown, the impeller 3 is a semi-open impeller, which is composed of an impeller rear cover plate 7, a magnetic drive seat 8, blades 9, and a shaft support frame 10.

[0036] The magnetic drive seat 8 is in a circular shape, and the inner and outer ring edges of the magnetic drive seat 8 are respectively provided with an outer wall and an inner wall, and a plurality of slots 11 are evenly arranged on the inner side of the outer wall around the outer ring, and magnetic blocks are installed in the slots 11; the inner surface of the inner wall is fixed with an axis support frame 10. The center of the axis support frame 10 is connected to the bearing 6. The axis support frame 10 is formed of three support legs, and the three support legs divide the inner circle of the magnetic drive seat 8 into three equal parts.

[0037] The impeller rear cover plate 7 is in a circular shape, and four blades 9 are evenly arranged on the surface of the impeller rear cover plate 7. The outer ring of the impeller rear cover plate 7 matches the outer wall of the magnetic drive seat 8, and the inner ring matches the inner wall of the magnetic drive seat 8, which is used to cover the magnetic drive seat 8 and seal to prevent blood from entering the magnetic drive seat 8.

[0038] like Figure 6 and 7 As shown, a hemispherical groove 12 is provided at the center of the shaft support frame 10, and a spherical protrusion 13 is provided at the top of the bearing 6; the spherical protrusion 13 is inserted into the groove 12 to form a rotation feature.

[0039] The centrifugal heart pump has a flow rate of 5 L / min under design conditions and a head of 1.63 mH2O;

[0040] Centrifugal heart pump specific speed

[0041]

[0042] Then, we adopt the design of increasing the flow rate. Then, we use the corrected coefficients and various factors to design a more reasonable combination of flow and geometric parameters, which can be expressed as:

[0043] n s '=k2×n s

[0044] Q'=k1×Q

[0045] The inlet pipe 4 is of a gradually expanding type with an expansion angle of 7 degrees in order to prevent the generation of vortex flow due to drastic geometric changes.

[0046] Inlet pipe inlet diameter:

[0047]

[0048] (D s Take 22mm)

[0049] Outlet pipe outlet diameter

[0050]

[0051] Pump inlet speed

[0052]

[0053] Pump outlet speed

[0054]

[0055] Efficiency determination

[0056] Volumetric efficiency

[0057]

[0058] Disk loss efficiency

[0059]

[0060] Mechanical efficiency

[0061] η m =η m '-0.02 = 0.845

[0062] Hydraulic efficiency

[0063]

[0064] Total efficiency

[0065] η=η h η m η v

[0066] η=0.802×0.845×0.956=0.648

[0067] Determine power

[0068] Shaft power:

[0069]

[0070]

[0071] Motor power:

[0072]

[0073] Take P g =4.97×10 -3 kW, or select according to actual situation after calculation;

[0074] Torque:

[0075]

[0076] Minimum shaft diameter:

[0077]

[0078] Impeller main dimensions

[0079] Inlet equivalent diameter:

[0080]

[0081] Inlet diameter

[0082] Take D j =20mm;

[0083] Impeller outer diameter (selected here based on the results of similarity conversion and speed coefficient method)

[0084] After two precise calculations, the outer diameter of the impeller is selected as D2 = 50 mm;

[0085] Exit Width

[0086]

[0087]

[0088] Take b2=2.2*1.2=2.6mm and directly take 3mm (the outlet width of the semi-open impeller is 1.1-1.2 times b2); (k b2 Take 1.3)

[0089] The blade outlet angle (selected here by referring to the results of similarity conversion and velocity coefficient method) is 29 degrees; the blade inlet angle is 34 degrees.

[0090] Impeller outlet speed

[0091] Exit axial speed:

[0092]

[0093] Outlet circumferential speed:

[0094]

[0095] Outlet circumferential speed:

[0096]

[0097] Infinite number of blades outlet circular velocity

[0098]

[0099] Example 2

[0100] This embodiment only describes the differences from Embodiment 1, and the similarities are not described again;

[0101] like Figure 8 and 9 As shown, a spherical protrusion 14 is provided at the center of the shaft support frame 10, and a hemispherical groove 15 is provided at the top of the bearing 6; the spherical protrusion 14 is inserted into the groove 15 to form a rotation feature.

[0102] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the implementation methods of the present invention, and should be understood that the protection scope of the present invention is not limited to such special statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A low hemolysis rate centrifugal heart pump, characterized in that: include: Front pump cover, rear pump cover, impeller, inlet pipe and outlet pipe; The front pump cover and the rear pump cover are combined to form a spiral volute extrusion chamber; A spiral flow channel is arranged in the volute extrusion chamber, an inlet pipeline is arranged on the surface of the front pump cover and connected to the volute extrusion chamber, an outlet pipeline is arranged on the side of the rear pump cover and connected to the volute extrusion chamber, and an impeller is arranged in the volute extrusion chamber; a bearing is arranged at the center of the rear pump cover, the shape of the rear pump cover can accommodate the entire impeller, the center of the impeller is connected to the bearing, and the bearing is used to support the impeller to rotate around the bearing; The impeller is a semi-open impeller, which consists of an impeller rear cover, a magnetic drive seat, blades, and a shaft support frame; The magnetic drive seat is in a circular shape, and the edges of the inner ring and outer ring of the magnetic drive seat are respectively provided with an outer wall and an inner wall, and a plurality of slots are evenly arranged on the inner side of the outer wall around the outer ring, and the magnetic blocks are installed in the slots; the inner surface of the inner wall is fixed with the shaft support frame; The center of the shaft support frame is provided with a hemispherical groove, and the top of the bearing is a spherical protrusion; the spherical protrusion is inserted into the groove to form a rotating feature; or the center of the shaft support frame is provided with a spherical protrusion, and the top of the bearing is a hemispherical groove; The shaft support frame is formed by three support legs, which divide the inner circle of the magnetic drive seat into three equal parts; The impeller rear cover is in a circular shape, and four blades are evenly arranged on the surface of the impeller rear cover. The outer ring of the impeller front cover matches the outer wall of the magnetic drive seat, and the inner ring matches the inner wall of the magnetic drive seat. The impeller front cover is used to cover the magnetic drive seat and seal to prevent blood from entering the magnetic drive seat. The centrifugal heart pump has a flow rate of 2-6 L / min and a head at the design operating point of 1.63 mH2O; The inlet pipe is of a gradually expanding type with an expansion angle of 7 degrees, an inlet diameter of the inlet pipe is 22 mm, and an outlet diameter of the outlet pipe is 17 mm; The heart pump has an inlet velocity of 0.405 m / s and an outlet velocity of 0.679 m / s; The impeller has an equivalent inlet diameter of 17 mm, an inlet diameter of 20 mm, an outer diameter of 50 mm, and an outlet width of 3 mm. The blade outlet angle is 29 degrees; the blade inlet angle is 34 degrees.

2. A low hemolysis rate centrifugal heart pump according to claim 1, characterized in that: The cross section of the support leg is an airfoil shape, which is beneficial for the blood to flow back from the gap between the impeller rear cover plate and the rear pump casing and to generate as few vortex flows as possible after flowing through the support leg.

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