Hemodynamics test system of pulsatile ventricular assist device

Abstract

The invention discloses a hemodynamic test system of a pulsating type ventricular assist device. The test system comprises a left atrium cavity, a left ventricular cavity, an aorta cavity, a vein cavity and a pulsating blood flow generator module. Two ends of the aortic valve module are respectively connected with the left ventricular cavity and the aortic cavity; the ventricular auxiliary device sequentially penetrates through an aorta cavity, an aortic valve module and a left ventricular cavity through a sealing tool of the aorta cavity, a blunt end is arranged in the left ventricular cavity, and a two-way valve is arranged in the aorta cavity. The pulsating blood flow generator module is connected with the left ventricular cavity, the left ventricular cavity is filled with liquid, the left ventricular model is extruded through reciprocating motion of a piston, and therefore the flowing rule of human blood is simulated. The test system can be used for simulating the front load and the rear load of the pulsating type ventricular assist device and detecting the hemodynamic performance of the ventricular assist device after the ventricular assist device is implanted into a human body, and structural optimization of the ventricular assist device and design of a controller are facilitated.

Description

Technical Field

[0001] The present invention relates to the field of performance testing of ventricular assist devices, and in particular provides a hemodynamic testing system for a pulsatile ventricular assist device. Background Art

[0002] The pulsatile ventricular assist device is a new type of catheter pump that can assist in providing pulsatile blood flow. It is minimally invasively implanted into patients with cardiogenic shock or high-risk PCI (percutaneous coronary intervention) through the femoral artery or axillary artery. Among them, the pulsatile blood flow can help the blood perfusion of the patient's organs, improve blood microcirculation, and reduce the risk of blood damage in the previous rotary blood pump, thereby improving the patient's postoperative recovery rate and reducing the probability of complications.

[0003] Compared with the principle and structure of a rotary blood pump, the structure of a pulsatile ventricular assist device is special, and its perfusion flow and pressure are affected by preload (pressure in the left ventricle) and afterload (pressure in the aorta). Therefore, in order to evaluate whether the hemodynamic performance of the pulsatile ventricular assist device meets clinical needs, it is necessary to design a test system that can simulate the patient's true hemodynamic state. By changing the pressure in the left ventricle and aorta, the sensitivity of the output flow and pressure of the pulsatile ventricular assist device to the preload and afterload can be analyzed, which helps to optimize the gas drive controller and device structure of the pulsatile ventricular assist device. Summary of the invention

[0004] Therefore, an object of the present invention is to provide a hemodynamic testing system for a pulsatile ventricular assist device, which can simulate the working state of a ventricular assist device implanted in a patient.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions: A hemodynamic test system for a pulsatile ventricular assist device, the test system comprising: a left atrial cavity, a left ventricular cavity, an aortic cavity, a venous cavity and a pulsatile blood flow generator module, The first interface of the left ventricular cavity is connected to the aortic cavity through the aortic valve module; the second interface of the left ventricular cavity is connected to the left atrial cavity, the left atrial cavity is connected to the venous cavity, and the venous cavity is connected to the aortic cavity; The ventricular assist device is composed of a catheter assembly and a membrane pump assembly. The catheter assembly includes a blunt tip and a short arterial tube, a two-way valve and a long arterial tube connected to the blunt tip in sequence. The catheter assembly passes through the aortic cavity, the aortic valve module and the left ventricular cavity in sequence through the sealing tool of the aortic cavity, and the blunt tip is placed in the left ventricular cavity and the two-way valve is placed in the aortic cavity; one end of the membrane pump assembly is connected to the long arterial tube of the catheter assembly, and the other end is connected to the gas drive controller; The pulsating blood flow generator module includes a piston pump and a compliance cavity, and the compliance cavity is connected to the power source interface at the bottom of the left ventricular cavity; A left ventricular model is provided in the left ventricular cavity, and the left ventricular cavity is divided into an inner cavity and an outer cavity, and the inner and outer cavities are not interconnected; the inner cavity is communicated with the aortic cavity, the venous cavity and the left atrium cavity, and is filled with liquid; the outer cavity is communicated with the piston pump and the compliance cavity, and is filled with liquid; The left ventricle model in the left ventricle cavity is squeezed by the reciprocating motion of the piston of the piston pump, and the liquid is first introduced from the left ventricle cavity into the membrane pump assembly, and then the liquid is infused into the aorta cavity through the work of the membrane pump assembly, thereby simulating the flow law of human blood.

[0006] Furthermore, the left atrial cavity, left ventricular cavity, aortic cavity and venous cavity are all equipped with pressure sensors for monitoring, and the left ventricular cavity is measured by a disposable invasive pressure sensor.

[0007] Furthermore, a first pipeline connects the aortic cavity and the venous cavity, and a throttle valve is provided on the first pipeline; a second pipeline connects the venous cavity and the left atrial cavity, and an ultrasonic flow sensor is installed on the second pipeline for measurement.

[0008] Furthermore, the left ventricle model has two interfaces, respectively connected to a first interface and a second interface of the left ventricle cavity.

[0009] Furthermore, the inner cavity of the left ventricular cavity is filled with liquid such as water or a glycerol-water mixture, and the outer cavity is filled with distilled water.

[0010] Furthermore, the left atrial cavity, left ventricular cavity, aortic cavity and venous cavity are all made of transparent materials, such as acrylic, polycarbonate, etc.

[0011] Furthermore, the aortic cavity includes a liquid storage cylinder, a piston slider, a gland plate, a screw, a Luer tee and a sealing ring; wherein the gland plate is connected to the top of the liquid storage cylinder by bolts, the screw is passed through the gland plate and its two ends are respectively connected to the piston slider and the Luer tee; through holes are provided in the center of the screw and the piston slider for the exhaust function before the test.

[0012] Furthermore, the piston slider is driven to move up and down by rotating the screw rod, thereby changing the height between the piston slider and the bottom of the liquid storage cylinder, thereby achieving the function of adjusting different aortic compliances.

[0013] Furthermore, a film and a pressure ring are installed on the top of the left atrial cavity; wherein a film is placed between the pressure ring and the left atrial cavity, and the three are fixed by bolts; wherein the film has a thickness ranging from 0.2 to 0.5 mm.

[0014] Furthermore, the aortic valve module includes an aortic valve, a first splint, a second splint, a first clip and a second clip; wherein the first splint and the first clip are connected by screws to fix the flange surface at one end of the aortic valve, and the second splint and the second clip are connected by screws to fix the flange surface at the other end of the aortic valve.

[0015] Furthermore, the left ventricle model and the aortic valve are both made of elastomeric materials such as transparent silicone or polyurethane, and are processed by 3D printing or compression molding.

[0016] Furthermore, the sealing tool is installed at the bottom of the aortic cavity, and mainly includes a sealing body, a conical silicone pad and a locking cap; wherein the conical silicone pad is placed in the conical groove of the sealing body, and the sealing body, the conical silicone pad and the locking cap are all provided with a central through hole; the inner annular surface of the locking cap is pressed against the end face of the conical silicone pad, and the outer annular side face of the locking cap is connected to the sealing body by a thread; the locking cap is rotated to squeeze the conical silicone pad downward through the inner annular surface, forcing the conical silicone pad to deform under force, resulting in a reduction in the diameter of the center hole, so that it contacts the ventricular assist device and forms an extrusion seal.

[0017] Beneficial effects of the present invention: The hemodynamic test system of a pulsatile ventricular assist device of the present invention includes the main part of the systemic circulation from the left atrium to the vein, and can generate a pulsatile blood flow environment, and can more realistically reproduce the hemodynamic characteristics of the patient and the front and back loads of the ventricular assist device. This test system can help the in vitro performance test of the pulsatile ventricular assist device and provide guidance for optimizing the device structure and controller performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0019] Figure 1 The figure is a general diagram of the ventricular assist device testing system provided by the present invention.

[0020] Figure 2 This is a diagram of the structure of a pulsatile ventricular assist device.

[0021] Figure 3 yes Figure 1 Top view of the test system.

[0022] Figure 4 yes Figure 3 Cross-section along the AA direction.

[0023] Figure 5It is a schematic diagram of the connection between the left ventricular cavity and the aortic cavity.

[0024] Figure 6 It is a structural diagram of the left ventricular cavity.

[0025] Figure 7 This is an exploded view of the aortic cavity.

[0026] Figure 8 It is a structural diagram of the left atrial cavity.

[0027] Fig. 9 is an exploded view of the aortic valve module.

[0028] Fig.10 It is a cross-sectional view of the sealing tooling.

[0029] Fig.11 It is a three-dimensional structural schematic diagram of the sealing tooling. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] In the description of the present invention, it is necessary to understand that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating a specific position that the device or structure referred to must have, and therefore cannot be understood as a limitation on the present invention.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0033] An embodiment of the present invention provides a hemodynamic performance testing system for a pulsatile ventricular assist device, which can simulate the hemodynamic characteristics of a patient's cardiovascular system and can evaluate the output flow, pressure and other performance of the pulsatile ventricular assist device under real conditions.

[0034] See also Figure 1As shown, the present invention proposes a test system 1 for a pulsatile ventricular assist device, which is used for in vitro testing of the hemodynamic performance of a pulsatile ventricular assist device 2. The test system 1 includes a left atrial cavity 11, a left ventricular cavity 12, an aortic cavity 13, a venous cavity 14, and a pulsating blood flow generator module 15. The left ventricular cavity 12 is connected to the aortic cavity 13 through an aortic valve module 16, the first pipeline 17 connects the aortic cavity 13 and the venous cavity 14, the left ventricular cavity 12 is connected to the venous cavity 14 via the left atrial cavity 11, and the second pipeline 18 connects the venous cavity 14 and the left atrial cavity 11.

[0035] See also Figure 2 As shown, the pulsatile ventricular assist device 2 is composed of a catheter assembly 21 and a membrane pump assembly 22. The catheter assembly 21 includes a blunt tip 211, a short arterial tube 213, a two-way valve 212 and a long arterial tube 214, and the blunt tip 211 is sequentially connected to the short arterial tube 213, the two-way valve 212 and the long arterial tube 214. The catheter assembly 21 is percutaneously implanted into the patient's body along the femoral artery or axillary artery, so that the blunt tip 211 is placed in the left ventricle and the two-way valve 212 is placed in the aortic arch. Figure 1 and Figure 2 As shown, one end of the membrane pump assembly 22 is connected to the long arterial tube 214 of the catheter assembly 21, and the other end is connected to the gas drive controller. The gas drive controller applies cyclic positive and negative pressure to the membrane pump assembly 22, so that blood periodically flows from the left ventricle through the blunt tip 211 to the membrane pump assembly 22, and then is driven by the positive pressure of the membrane pump assembly 22 to flow through the two-way valve 212 and perfused into the aorta. This principle can reduce the load on the left ventricle and provide pulsatile blood flow perfusion for patients, thereby reducing the chance of complications caused by the continuous flow ventricular assist device. The test system 1 can evaluate the working state of the pulsatile ventricular assist device 2 in a real blood flow environment, help to judge the rationality of the structure of the two-way valve 212 or the membrane pump assembly 22, and also provide a reference for the pressure regulation of the gas drive controller.

[0036] See also Figure 3As shown, the test system 1 is provided with a plurality of pressure sensors, including a first pressure sensor 1111, a second pressure sensor 1211, a third pressure sensor 1311 and a fourth pressure sensor 1411, which are used to monitor the pressures in the left atrial cavity 11, the left ventricular cavity 12, the aortic cavity 13 and the venous cavity 14, respectively. Among them, the second sensor 1211 is connected to the Luer connector using a disposable invasive pressure sensor, and both the disposable invasive pressure sensor and the Luer connector are standard purchased parts. A flow sensor 1511 is installed on the second pipeline 18 to monitor flow changes in the test system. The flow sensor 1511 is an ultrasonic flow sensor. In addition, the flow sensor 1511 can also be installed on the first pipeline 17. In order to adjust the peripheral resistance of the test system, a throttle valve 1611 is installed on the first pipeline 17. In combination with Figure 1 and Figure 3 As shown, the left atrial cavity 11, the left ventricular cavity 12, the aortic cavity 13 and the venous cavity 14 are interconnected, and liquid is perfused in the cavity to simulate blood flow. The liquid can be water, glycerol-water mixture, etc.

[0037] See also Figure 4 As shown, the pulsatile ventricular assist device 2 is installed in the left ventricular cavity 12 and the aortic cavity 13. Through the action of the membrane pump assembly 22, blood is first introduced from the left ventricular cavity 12 into the membrane pump assembly 22, and then the blood is perfused into the aortic cavity 13 through the work of the membrane pump assembly 22. The pulsatile blood flow generator module 15 includes a piston pump 151 and a compliance cavity 152, which are sequentially connected to the bottom of the left ventricular cavity 12 through pipelines. Figure 5 As shown, a left ventricle model 121 is set in the left ventricle cavity 12. The left ventricle model 121 is made of elastic materials such as silicone or polyurethane, and can be made by 3D printing or molding, and its volume range is between 150-300 mL. A power source interface 125 is provided at the bottom of the left ventricle cavity 12 for connecting the pulsating blood flow generator module 15. In addition, a sealing tool 19 is provided on the bottom side of the aortic cavity 13.

[0038] Combination Figure 5 and Figure 6As shown, the left ventricle model 121 is fixed in the left ventricle cavity 12, and is connected to the first interface 123 and the second interface 124 respectively; wherein the first interface 123 is connected to the aortic cavity 13, and the second interface 124 is connected to the left atrium cavity 11. A square cover plate 122 is installed on the top of the left ventricle cavity 12, and is sealed and connected to the sealing gasket and the left ventricle cavity 12 by bolts. The left ventricle model 121 divides the left ventricle cavity 12 into an inner cavity a and an outer cavity b, and the outer cavity b is connected to the piston pump 151 and the compliance cavity 152, and is filled with distilled water; the inner cavity a is connected to the left atrium cavity 11 and the aortic cavity 13 respectively. Therefore, the left ventricle model 121 separates the inner cavity a and the outer cavity b and does not communicate with each other. A pressure measuring tube 125 is provided on the side of the left ventricle model 121, which passes through the side plate of the left ventricle cavity 12 and extends out, and is used to connect the Luer connector and the disposable invasive pressure sensor.

[0039] See also Figure 7 As shown, the aortic cavity 13 includes a liquid storage cylinder 131, a piston slider 132, a gland plate 133, a screw rod 134, a Luer tee 135 and a sealing ring 136. Figure 5 and Figure 7 As shown, the piston slider 132 is tightly matched with the inner wall of the liquid storage cylinder 131 through the sealing ring 136, and the pressure cover plate 133 is installed on the top of the liquid storage cylinder 131 and fixed by bolt connection. The screw rod 134 is arranged in the center of the pressure cover plate 133 and is fixed to the piston block 132; wherein, the screw rod 134 and the pressure cover plate 133 are threadedly transmitted. Through holes are provided in the center of the piston slider 132 and the screw rod 134, and the two are mutually connected, and the Luer tee 135 is connected to the top of the screw rod 134. The function of adjusting the compliance of the aorta is realized by changing the height H between the piston slider 132 and the bottom of the liquid storage cylinder. The increase of the height H can improve the compliance of the aorta, and vice versa, the compliance of the aorta is weakened. In order to improve the airtightness between the piston slider 132 and the liquid storage cylinder 132, at least two sealing rings 136 are selected to be superimposed and used.

[0040] Before the test system is used, the Luer Tee 135 needs to be opened to allow the aortic cavity 13 to communicate with the atmosphere. After the test system is injected with liquid, the Luer Tee 135 is closed.

[0041] See also Figure 8As shown, the left atrial cavity 11 includes a cavity body 111, a pressure ring 112 and a film 113. The film 113 can be made of a polymer elastomer such as silicone or polyurethane, and the thickness is between 0.2-0.5 mm. The pressure ring 112 fixes the film 113 to the top of the cavity body 111 by bolts, and seals the top of the left atrial cavity 11. This method can simulate the weak pulsation effect of the left atrium, thereby approaching the actual situation of the patient. An interface 1112 and a protrusion 1114 are provided on the side of the bottom of the left atrial cavity 11, which are used to connect the second interface 124 of the left ventricular cavity 12, and a sealing gasket is used between the two to prevent liquid leakage. In addition, an interface 1113 is provided at the bottom of the left atrial cavity 11 for installing a first pressure sensor 1111.

[0042] See also Fig. 9 As shown, the aortic valve module includes an aortic valve 161, a first clamp 162, a second clamp 163, a first clip 164 and a second clip 165. The aortic valve 161 is made of the same material and processing method as the left ventricle model 121, and is made of elastomeric materials such as silicone or polyurethane, and is made by 3D printing or compression molding. A first flange surface 1611 and a first flange surface 1612 are provided at both ends of the aortic valve 161, and a plurality of through holes are provided on the flange surface. The first clip 164 presses the first flange surface 1611 into the groove of the first clamp 162 and is connected by screws; and the second flange surface 1612 is fixed between the second clamp 163 and the second clip 165 in the same way.

[0043] The left atrium cavity 11, the left ventricle cavity 12, the aorta cavity 13 and the vein cavity 14 are all made of transparent materials, such as acrylic, polycarbonate, etc. This makes it easy to observe the flow of liquid in the test system and monitor whether there are bubbles mixed in the circulation loop. When the first pipeline 17 and the second pipeline 18 are connected to the cavities respectively, they are both connected by pagoda joints.

[0044] See also Figure 5 , Fig.10 and Fig.11As shown, the sealing tool 19 is installed at the bottom of the aortic cavity 13 to facilitate the implantation of the ventricular assist device 2 and prevent liquid from leaking from the implantation position. The sealing tool 19 includes a sealing body 191, a conical silicone pad 192 and a locking cap 193, and through holes are set at the centers of these three parts. The conical silicone pad 192 is placed in the conical groove of the sealing body 191, and the inner annular surface 1931 of the locking cap 193 abuts against the upper end surface of the conical silicone pad 192, and the outer annular surface 1932 is connected to the outer surface of the sealing body 191 by a thread. By rotating the locking cap handle 1933, the locking cap 193 moves downward along the axial direction of the sealing tool 19, thereby continuously squeezing the conical silicone pad 192, forcing the central hole of the conical silicone pad 192 to be continuously compressed and reduced, and finally forming an extrusion seal with the catheter assembly of the ventricular assist device 2.

[0045] The above are preferred embodiments of the present invention and the technical principles used therein. For those skilled in the art, any obvious changes such as equivalent transformations, simple replacements, etc. based on the technical solution of the present invention, without departing from the spirit and scope of the present invention, are within the scope of protection of the present invention.

Claims

1. A hemodynamic test system for a pulsatile ventricular assist device, the test system comprising: The left atrial cavity, the left ventricular cavity, the aortic cavity, the venous cavity and the pulsatile blood flow generator module, The first interface of the left ventricular cavity is connected to the aortic cavity through the aortic valve module; the second interface of the left ventricular cavity is connected to the left atrial cavity, the left atrial cavity is connected to the venous cavity, and the venous cavity is connected to the aortic cavity; The ventricular assist device is composed of a catheter assembly and a membrane pump assembly. The catheter assembly includes a blunt tip and a short arterial tube, a two-way valve and a long arterial tube connected to the blunt tip in sequence. The catheter assembly passes through the aortic cavity, the aortic valve module and the left ventricular cavity in sequence through the sealing tool of the aortic cavity, and the blunt tip is placed in the left ventricular cavity and the two-way valve is placed in the aortic cavity; one end of the membrane pump assembly is connected to the long arterial tube of the catheter assembly, and the other end is connected to the gas drive controller; The pulsating blood flow generator module includes a piston pump and a compliance cavity, and the compliance cavity is connected to the power source interface at the bottom of the left ventricular cavity; A left ventricular model is provided in the left ventricular cavity, and the left ventricular cavity is divided into an inner cavity and an outer cavity, and the inner and outer cavities are not interconnected; the inner cavity is communicated with the aortic cavity, the venous cavity and the left atrium cavity, and is filled with liquid; the outer cavity is communicated with the piston pump and the compliance cavity, and is filled with liquid; The left ventricle model in the left ventricle cavity is squeezed by the reciprocating motion of the piston of the piston pump, and the liquid is first introduced from the left ventricle cavity into the membrane pump assembly, and then the liquid is infused into the aorta cavity through the work of the membrane pump assembly, thereby simulating the flow law of human blood.

2. The test system according to claim 1, characterized in that: The left atrial cavity, left ventricular cavity, aortic cavity and venous cavity are all equipped with pressure sensors for monitoring, and the left ventricular cavity is measured by a disposable invasive pressure sensor.

3. The test system according to claim 1, characterized in that: The first pipeline connects the aortic cavity and the venous cavity, and a throttle valve is arranged on the first pipeline; the second pipeline connects the venous cavity and the left atrial cavity, and an ultrasonic flow sensor is arranged on the second pipeline for measurement.

4. The left ventricular cavity according to claim 1, characterized in that: The left ventricle model has two interfaces, which are respectively connected to a first interface and a second interface of the left ventricle cavity.

5. The left ventricular cavity according to claim 1, characterized in that: The inner cavity of the left ventricular cavity is filled with water or a glycerol-water mixture; and the outer cavity of the left ventricular cavity is filled with distilled water.

6. The test system according to claim 1, characterized in that: The left atrial cavity, the left ventricular cavity, the aortic cavity and the venous cavity are all made of transparent acrylic or polycarbonate.

7. The test system according to claim 1, characterized in that: The aortic cavity includes a liquid storage cylinder, a piston slider, a gland plate, a screw, a Luer tee and a sealing ring; wherein the gland plate is connected to the top of the liquid storage cylinder by bolts, the screw is passed through the gland plate and the two ends are respectively connected to the piston slider and the Luer tee; through holes are provided in the center of the screw and the piston slider for the exhaust function before the test.

8. The aortic cavity according to claim 7, characterized in that: The piston slider is driven to move up and down by rotating the screw rod, thereby changing the height between the piston slider and the bottom of the liquid storage cylinder, thereby achieving the function of adjusting different aortic compliances.

9. The test system according to claim 1, characterized in that: A film and a pressure ring are installed on the top of the left atrial cavity; wherein a film is placed between the pressure ring and the left atrial cavity, and the three are fixed by bolts; wherein the thickness of the film ranges from 0.2 to 0.5 mm.

10. The test system according to claim 1, characterized in that: The aortic valve module includes an aortic valve, a first splint, a second splint, a first clip and a second clip; wherein the first splint and the first clip are connected by screws to fix the flange surface at one end of the aortic valve, and the second splint and the second clip are connected by screws to fix the flange surface at the other end of the aortic valve.

11. The left ventricle model and aortic valve according to claim 1 or 10, characterized in that: The left ventricle model and the aortic valve are both made of elastomeric materials such as transparent silicone or polyurethane and are processed by 3D printing or compression molding.

12. The test system according to claim 1, characterized in that: The sealing tool is installed at the bottom of the aortic cavity, and mainly includes a sealing body, a conical silicone pad and a locking cap; wherein the conical silicone pad is placed in the conical groove of the sealing body, and the sealing body, the conical silicone pad and the locking cap are all provided with a central through hole; the inner annular surface of the locking cap is pressed against the end surface of the conical silicone pad, and the outer annular side surface of the locking cap is connected to the sealing body by a thread; the locking cap is rotated to squeeze the conical silicone pad downward through the inner annular surface, forcing the conical silicone pad to deform under force, resulting in a reduction in the diameter of the central through hole, so that it contacts the ventricular assist device and forms an extrusion seal.

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