Hemodynamic test system of pulsating ventricular assist deviceTechnical Field
The invention relates to the field of performance testing of ventricular assist devices, in particular to a hemodynamic testing system of a pulsating ventricular assist device.
Background
The pulsating ventricular assist device is a novel catheter pump which can assist in providing pulsating blood flow and is implanted into a patient with cardiogenic shock or high risk PCI (coronary intervention) through femoral artery or axillary artery minimally invasive. The pulsatile blood flow can be helpful for blood perfusion of the tail ends of organs of a patient, improves blood microcirculation, reduces the risk of blood damage existing in the conventional rotary blood pump, improves the postoperative recovery probability of the patient and reduces the complication probability.
Compared with the principle and structure of a rotary blood pump, the structure of the pulse type ventricular assist device has specificity, and the perfusion flow and pressure of the pulse type ventricular assist device are influenced by the preload (left ventricular pressure) and the afterload (aortic pressure) to change. Therefore, in order to evaluate whether the hemodynamic performance of the pulsatile ventricular assist device meets clinical requirements, it is desirable to design a test system that simulates the actual state of patient hemodynamics. By varying the pressures in the left ventricle and the aorta, the sensitivity of the pulsatile ventricular assist device output flow and pressure to fore and aft loading is analyzed, which facilitates optimization of the gas drive controller and device configuration of the pulsatile ventricular assist device.
Disclosure of Invention
It is therefore an object of the present invention to provide a hemodynamic testing system for a pulsatile ventricular assist device that simulates the operation of the ventricular assist device when implanted in a patient.
In order to achieve the above purpose, the invention adopts the following technical scheme:
A hemodynamic testing system of a pulsatile ventricular assist device includes a left atrial chamber, a left ventricular chamber, an aortic chamber, a venous chamber, and a pulsatile flow generator module,
The second interface of the left ventricular cavity is connected with the left atrium cavity, the left atrium cavity is connected with the vein cavity, and the vein cavity is connected with the aorta cavity;
The ventricular assist device consists of a catheter assembly and a membrane pump assembly, wherein the catheter assembly comprises a blunt end, an arterial short tube, a two-way valve and an arterial long tube which are sequentially connected with the blunt end, the catheter assembly sequentially passes through an aortic cavity, an aortic valve module and a left ventricular cavity through a sealing tool of the aortic cavity, and enables the blunt end to be arranged in the left ventricular cavity and the two-way valve to be arranged in the aortic cavity;
the pulsatile flow generator module comprises a piston pump and a compliance cavity, wherein the compliance cavity is communicated with a power source interface at the bottom of the left ventricle cavity;
The left ventricle cavity is internally provided with a left ventricle model which divides the left ventricle cavity into an inner cavity and an outer cavity, and the inner cavity and the outer cavity are not communicated with each other;
The left ventricle model in the left ventricle cavity is extruded through the reciprocating motion of the piston pump, liquid is firstly introduced into the membrane pump assembly from the left ventricle cavity, and the liquid is poured into the aortic cavity through the acting of the membrane pump assembly, so that the flow rule of human blood is simulated.
Further, the left atrium cavity, the left ventricle cavity, the aortic cavity and the venous cavity are all provided with pressure sensor monitoring, and the left ventricle cavity is measured by adopting a disposable invasive pressure sensor.
Further, a first pipeline is connected with the aortic cavity and the venous cavity, a throttle valve is arranged on the first pipeline, a second pipeline is connected with the venous cavity and the left atrium cavity, and an ultrasonic flow sensor is arranged on the second pipeline for measurement.
Further, the left ventricular model has two interfaces, which are respectively connected with the first interface and the second interface of the left ventricular cavity.
Further, the inner cavity of the left ventricle cavity is filled with water or liquid such as glycerin-water mixture, and the outer cavity is filled with distilled water.
Further, the left atrium cavity, the left ventricle cavity, the aorta cavity and the vein cavity are all made of transparent materials, such as acrylic, polycarbonate and the like.
The aortic cavity comprises a liquid storage cylinder, a piston sliding block, a gland plate, a screw rod, a luer tee joint and a sealing ring, wherein the gland plate is connected with the top end of the liquid storage cylinder through bolts, the screw rod penetrates through the gland plate, two ends of the screw rod are respectively connected with the piston sliding block and the luer tee joint, and through holes are formed in the centers of the screw rod and the piston sliding block and used for exhausting functions before experiments.
Further, the screw rod is rotated to drive the piston slide block to move up and down, so that the height between the piston slide block and the bottom of the liquid storage barrel is changed, and the function of adjusting the compliance of different aorta is realized.
Further, a film and a compression ring are arranged on the top of the left atrium cavity, wherein the film is arranged between the compression ring and the left atrium cavity and fixed between the compression ring and the left atrium cavity through bolts, and the thickness of the film ranges from 0.2 to 0.5mm.
The aortic valve module comprises an aortic valve, a first clamping plate, a second clamping plate, a first clamping piece and a second clamping piece, wherein the first clamping plate and the first clamping piece are connected through screws to fix one end flange surface of the aortic valve, and the second clamping plate and the second clamping piece are connected through screws to fix the other end flange surface of the aortic valve.
Further, the left ventricle model and the aortic valve are made of transparent silica gel or polyurethane and other elastomer materials, and are processed through 3D printing or compression molding and other modes.
The sealing tool is arranged at the bottom of the aortic cavity and mainly comprises a sealing main body, a conical silica gel pad and a locking cap, wherein the conical silica gel pad is arranged in a conical groove of the sealing main body, the conical silica gel pad and the locking cap are respectively provided with a central through hole, an inner annular surface of the locking cap is propped against the end surface of the conical silica gel pad, an outer annular side surface of the locking cap is in threaded connection with the sealing main body, the conical silica gel pad is extruded downwards through the inner annular surface by rotating the locking cap, and the diameter of the central hole is reduced due to forced deformation of the conical silica gel pad, so that the sealing tool is contacted with a ventricular auxiliary device and forms extrusion sealing.
The invention has the beneficial effects that:
The hemodynamic test system of the pulsatile ventricular assist device comprises a main part of the systemic circulation from the left atrium to the vein, can generate a pulsatile blood flow environment, and can more truly reproduce the hemodynamic characteristics of a patient and the front load and the rear load of the ventricular assist device. This test system can facilitate in vitro performance detection of the pulsatile ventricular assist device, providing guidance for optimizing device architecture and controller performance.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly described below.
Fig. 1 is a general diagram of a ventricular assist device testing system provided by the present invention.
Fig. 2 is a block diagram of a pulsatile ventricular assist device.
Fig. 3 is a top view of the test system of fig. 1.
Fig. 4 is a cross-sectional view of fig. 3 taken along the direction A-A.
Fig. 5 is a schematic illustration of the connection of the left ventricular cavity to the aortic cavity.
Fig. 6 is a block diagram of a left ventricular cavity.
Fig. 7 is an exploded view of the aortic lumen.
Fig. 8 is a block diagram of the left atrial chamber.
Fig. 9 is an exploded view of the aortic valve module.
Fig. 10 is a cross-sectional view of a sealing tool.
Fig. 11 is a schematic perspective view of a sealing tool.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
In the description of the present invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention, and do not indicate a specific location that the device or structure referred to must have, and thus should not be construed as limiting the present invention.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
The embodiment of the invention provides a hemodynamic performance test system of a pulsating ventricular assist device, which can simulate hemodynamic characteristics in a cardiovascular system of a patient and can evaluate the output flow, pressure and other performances of the pulsating ventricular assist device in a real state.
Referring to fig. 1, the present invention proposes a testing system 1 for a pulsatile ventricular assist device for in vitro testing of hemodynamic performance of the pulsatile ventricular assist device 2. The test system 1 comprises a left atrial chamber 11, a left ventricular chamber 12, an aortic chamber 13, a venous chamber 14 and a pulsatile flow generator module 15. The left ventricle cavity 12 is connected with the aortic cavity 13 through the aortic valve module 16, the first pipeline 17 is connected with the aortic cavity 13 and the venous cavity 14, the left ventricle cavity 12 is connected with the venous cavity 14 through the left atrium cavity 11, and the second pipeline 18 is connected with the venous cavity 14 and the left atrium cavity 11.
Referring to fig. 2, the pulsatile ventricular assist device 2 is comprised of a catheter assembly 21 and a membrane pump assembly 22. The catheter assembly 21 includes a blunt tip 211, an arterial short tube 213, a bi-directional valve 212, and an arterial long tube 214, wherein the blunt tip 211 is sequentially connected with the arterial short tube 213, the bi-directional valve 212, and the arterial long tube 214. Catheter assembly 21 is percutaneously implanted in a patient along the femoral or axillary artery such that blunt tip 211 is placed in the left ventricle and bi-directional valve 212 is placed in the aortic arch. As shown in connection with fig. 1 and 2, the membrane pump assembly 22 is connected at one end to the arterial tube 214 of the catheter assembly 21 and at the other end to the gas drive controller. The gas-driven controller causes blood to be periodically drawn from the left ventricle through the blunt tip 211 into the membrane pump assembly 22 by applying cyclical positive and negative pressures to the membrane pump assembly 22, and then to be perfused into the aorta through the bi-directional valve 212 by positive pressure driving of the membrane pump assembly 22. The principle can play a role in reducing the load of the left ventricle, and provides pulsating blood flow perfusion for a patient, so that the probability of complications caused by the continuous flow ventricular assist device is reduced. The test system 1 can evaluate the operating state of the pulsatile ventricular assist device 2 in a real blood flow environment, helping to determine the structural rationality of the bi-directional valve 212 or the membrane pump assembly 22, and also providing a reference for pressure regulation of the gas-driven controller.
Referring to fig. 3, 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 for monitoring the pressure in the left atrial chamber 11, the left ventricular chamber 12, the aortic chamber 13 and the venous chamber 14, respectively. The second sensor 1211 is connected to the luer connector by a disposable invasive pressure sensor, and the disposable invasive pressure sensor and the luer connector are standard purchasing components. A flow sensor 1511 is mounted on the second conduit 18 for monitoring flow changes in the test system, the flow sensor 1511 being an ultrasonic flow sensor. In addition, the flow sensor 1511 may be mounted on the first pipe 17. To adjust the peripheral resistance of the test system, a throttle valve 1611 is mounted on the first line 17. As shown in fig. 1 and 3, the left atrium chamber 11, the left ventricle chamber 12, the aorta chamber 13 and the vein chamber 14 are communicated with each other, and a liquid, which may be water, a glycerin-water mixture, or the like, is poured into the chambers to simulate blood flow.
Referring to fig. 4, the pulsatile ventricular assist device 2 is disposed through the left ventricular chamber 12 and the aortic chamber 13, and blood is introduced into the membrane pump assembly 22 from the left ventricular chamber 12 by the action of the membrane pump assembly 22, and is perfused into the aortic chamber 13 again by the work of the membrane pump assembly 22. The pulsatile flow generator module 15 comprises a piston pump 151 and a compliant cavity 152 and is connected in turn to the bottom of the left ventricular chamber 12 by tubing. As shown in fig. 5, a left ventricle model 121 is disposed in the left ventricle cavity 12, and the left ventricle model 121 is made of an elastomer material such as silica gel or polyurethane, and can be manufactured by 3D printing or compression molding, and the volume range of the left ventricle model 121 is 150-300 mL. A power source interface 125 is provided at the bottom of the left ventricular chamber 12 for connection to the pulsatile flow generator module 15. In addition, the side of the bottom of the aortic cavity 13 is provided with a sealing tool 19.
Referring to fig. 5 and 6, the left ventricular model 121 is fixed in the left ventricular cavity 12 and is connected to a first port 123 and a second port 124, respectively, wherein the first port 123 is in communication with the aortic cavity 13, and the second port 124 is in communication with the left atrial cavity 11. A square cover plate 122 is arranged on the top of the left ventricle cavity 12 and is in sealing connection with the sealing gasket and the left ventricle cavity 12 through bolts. The left ventricle model 121 divides the left ventricle cavity 12 into an outer cavity a and an outer cavity b, the outer cavity b is communicated with the piston pump 151 and the compliance cavity 152 and is filled with distilled water, and the inner cavity a is respectively communicated with the left atrium cavity 11 and the aorta cavity 13. Thus, the left ventricular model 121 separates and does not communicate with the inner and outer chambers a, b. A pressure measuring tube 125 is arranged at the side of the left ventricle model 121, penetrates through the side plate of the left ventricle cavity 12 and extends out, and is used for connecting a luer connector and a disposable invasive pressure sensor.
Referring to fig. 7, the aortic chamber 13 includes a reservoir 131, a piston slider 132, a gland plate 133, a screw 134, a luer tee 135, and a sealing ring 136. As shown in fig. 5 and 7, the piston slider 132 is tightly matched with the inner wall of the liquid storage barrel 131 through a sealing ring 136, and the cover plate 133 is installed on the top of the liquid storage barrel 131 and is fixedly connected through bolts. The screw rod 134 penetrates through the center of the gland plate 133 and is fixedly connected with the piston block 132, wherein the screw rod 134 is in threaded transmission with the gland plate 133. Through holes are formed in the centers of the piston slide block 132 and the screw rod 134, the piston slide block 132 and the screw rod 134 are communicated with each other, and the luer tee 135 is connected to the top end of the screw rod 134. By changing the height H between the piston slider 132 and the bottom of the reservoir, the function of regulating aortic compliance is achieved. Increasing the height H may increase aortic compliance, whereas decreasing aortic compliance. In order to improve the tightness between the piston slide 132 and the liquid storage cylinder 132, at least two sealing rings 136 are selected for superposition.
Before the test system is used, the luer 135 is opened so that the main artery lumen 13 is vented to atmosphere, and after the test system is filled with fluid, the luer 135 is closed.
Referring to fig. 8, the left atrium chamber 11 includes a chamber body 111, a pressure ring 112, and a membrane 113. The film 113 can be made of polymer elastomer such as silica gel or polyurethane, and has a thickness of 0.2-0.5 mm. The pressure ring 112 secures the membrane 113 to the top of the chamber body 111 by bolts, sealing the top of the left atrium chamber 11. This approach simulates the faint pulsatile effect of the left atrium, thereby approximating the reality of the patient. The bottom side of the left atrial chamber 11 is provided with a port 1112 and a protrusion 1114 for connecting to the second port 124 of the left ventricular chamber 12, and a gasket is used therebetween to prevent fluid leakage. In addition, the bottom of the left atrial chamber 11 is provided with an interface 1113 for mounting the first pressure sensor 1111.
Referring to fig. 9, the aortic valve module includes an aortic valve 161, a first clamping plate 162, a second clamping plate 163, a first clamping plate 164, and a second clamping plate 165. The aortic valve 161 is made of an elastomer material such as silicone or polyurethane in the same manner as the left ventricle model 121, and is manufactured by 3D printing or compression molding. The aortic valve 161 is provided with a first flange surface 1611 and a first flange surface 1612 at both ends, and a plurality of through holes are provided on the flange surface. The first clamping piece 164 presses the first flange surface 1611 into the groove of the first clamping plate 162 and is connected by screws, and the second flange surface 1612 is fixed between the second clamping plate 163 and the second clamping piece 165 in the same manner.
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 and the like. Therefore, the liquid flowing condition in the test system can be conveniently observed, and whether the bubbles are mixed in the circulation loop or not can be monitored. When the first pipeline 17 and the second pipeline 18 are respectively connected with the cavity, a pagoda joint connection mode is adopted.
Referring to fig. 5, 10 and 11, a sealing tool 19 is mounted at the bottom of the aortic cavity 13 for facilitating implantation of the ventricular assist device 2 and preventing leakage of fluid from the implantation site. The sealing tool 19 comprises a sealing main body 191, a conical silica gel pad 192 and a locking cap 193, and through holes are formed in the centers of the three parts. The conical silica gel pad 192 is disposed in the conical groove of the sealing body 191, the inner circular surface 1931 of the locking cap 193 abuts against the upper end surface of the conical silica gel pad 192, and the outer circular surface 1932 is connected with the outer surface of the sealing body 191 through threads. By rotating the locking cap handle 1933, the locking cap 193 moves downward along the axial direction of the sealing tool 19, and further continuously presses the conical silica gel pad 192, forcing the central hole of the conical silica gel pad 192 to be continuously pressed smaller, and finally forming a pressing seal with the catheter assembly of the ventricular assist device 2.
The foregoing is a description of the preferred embodiments of the present invention and the technical principles applied thereto, and it will be apparent to those skilled in the art that any modifications, equivalent changes, simple substitutions and the like based on the technical scheme of the present invention can be made without departing from the spirit and scope of the present invention.