System for testing valve

Abstract

The invention relates to a system for testing a valve. A chamber assembly for testing a valve includes a proximal chamber portion defining a proximal interior space, a distal chamber portion defining a distal interior space converging with the proximal interior space, and a valve stent disposed between the proximal interior space and the distal interior space. The valve stent is configured to receive the valve in an aperture of the valve stent. The valve stent includes one or more return orifices such that the proximal interior space is in fluid communication with the distal interior space via the one or more return orifices.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority to U.S. Patent Application No. 14 / 306,508, filed on June 17, 2014, and U.S. Patent Application No. 14 / 643,629, filed on March 10, 2015. The entire contents of these applications are incorporated herein by reference. The divisional application of this application, whose parent application number is 201580044324.8, filed on June 17, 2015, and the invention name is "System for Testing a Valve", is directed to the divisional application number 202111107127.X, filed on June 17, 2015, and the invention name is "System for Testing a Valve". Technical Field

[0002] The present invention relates to systems and methods for testing valves. For example, the present invention relates to systems and methods for accelerated life testing of prosthetic heart valves. Background Art

[0003] Accelerated life testing (also called accelerated wear testing or durability testing) is a method of testing an article by subjecting it to conditions that exceed its normal service parameters (e.g., cycle time, stress, strain, temperature, voltage, vibration, pressure, etc.) in order to reveal faults and possible failure modes in a shortened amount of time. Accelerated life testing can be used to study materials, design concepts, design modifications, and durability changes resulting from changes in manufacturing techniques.

[0004] The ISO 5840-3:2013 standard outlines the methods used to qualify the design and manufacture of heart valve prostheses. ISO5840-3:2013 requires that mechanical heart valves be tested for at least 600 million cycles (equivalent to 15 years in vivo) and biological heart valve prostheses be tested for at least 200 million cycles (equivalent to 5 years in vivo) in a pulsatile flow simulator using the range of pressures seen under physiological conditions. The cyclic testing must also meet the following two requirements: 1) the test valve must fully open and close during each cycle, and 2) the pressure difference across the valve (transvalvular ΔP) must be at least a specified pressure (e.g., 100 mmHg for the aortic valve and 120 mmHg for the mitral valve) during at least 5% of each cycle. Summary of the invention

[0005] Provided herein are systems and methods for testing various valves. For example, provided herein are systems and methods for accelerated life testing of prosthetic heart valves. The systems and methods provided herein are very suitable for use with a variety of prosthetic heart valves and biological heart valves. For example, the systems and methods provided herein can be used to test prosthetic heart valves to be deployed at anatomical sites including but not limited to aortic valves, mitral valves, atrioventricular valves, pulmonary valves, etc. In addition, the systems and methods provided herein can be used to perform accelerated life testing on valve types such as but not limited to mechanical valves, tissue (biological) valves, tissue engineering valves, surgical implantable valves, and transcatheter implantable valves. The systems and methods provided herein can also be used for accelerated life testing of non-medical related valves.

[0006] All examples and features mentioned below can be combined in any technically feasible manner. In a specific implementation, a chamber assembly for testing a valve includes a proximal chamber portion defining a proximal interior space, a distal chamber portion defining a distal interior space that merges with the proximal interior space, and a valve support disposed between the proximal interior space and the distal interior space. The valve support is configured to receive a valve in a hole of the valve support. The valve support includes one or more regurgitation orifices so that the proximal interior space is in fluid communication with the distal interior space via the one or more regurgitation orifices.

[0007] Such a chamber assembly may optionally include one or more of the following features. The chamber assembly may be constructed so that when the chamber assembly is connected to an accelerated life test system, and when the valve is contained in the hole of the valve support, the bottom of the valve and the top of the valve can be seen by an observer. The chamber assembly may define a longitudinal axis, and the chamber assembly may be constructed so that when the chamber assembly is connected to an accelerated life test system, the longitudinal axis is tilted at an angle compared to the horizontal position. The angle may be between about 20° and about 70° from the horizontal position. The flow area (open area) of the one or more reflow orifices can be adjusted without removing the valve support from the chamber assembly. The chamber assembly may also include a first pressure sensor configured to measure the liquid pressure in the proximal internal space, and a second pressure sensor configured to measure the liquid pressure in the distal internal space. The chamber assembly may also include one or more lights, which are connected to the chamber assembly and configured to illuminate the valve. The distal chamber portion can be releasably attached to the proximal chamber portion. The valve support can be detachably arranged between the proximal internal space and the distal internal space. The chamber assembly may be configured for accelerated life testing of a valve. The chamber assembly may be configured to contain a liquid. The one or more reflow orifices may be positioned on the valve support so that at least the first reflow orifice of the one or more reflow orifices is located in the upper portion of the chamber, and at least the second reflow orifice of the one or more reflow orifices is located in the lower portion of the chamber. The hole of the valve support may be at least partially defined by a compliant sleeve configured to receive the valve, and the compliant sleeve may be configured to bend (deflect) in response to a pressure difference between the proximal interior space and the distal interior space. Three or more sides of the chamber assembly may be substantially transparent. The flow area of ​​the one or more reflow orifices may be selected based on the size of the valve to be tested.

[0008] In another specific implementation, a system for testing a valve includes a chamber assembly, a fluid displacement member, and an actuator configured to actuate the fluid displacement member. The chamber assembly includes a proximal chamber portion defining a proximal interior space, a distal chamber portion defining a distal interior space that merges with the proximal interior space, and a valve support disposed between the proximal interior space and the distal interior space. The valve support is configured to receive a valve in a hole of the valve support. The valve support includes one or more regurgitation orifices such that the proximal interior space is in fluid communication with the distal interior space via the one or more regurgitation orifices. The fluid displacement member defines a displacement member interior space that merges with the proximal interior space.

[0009] Such a system for testing a valve may optionally include one or more of the following features. When the valve is contained in the hole of the valve support and the valve support is disposed between the proximal chamber and the distal chamber, the bottom of the valve and the top of the valve are both visible to an observer. The chamber assembly defines a longitudinal axis, and when the chamber assembly is coupled to the fluid displacement member, the longitudinal axis is tilted at an angle relative to a vertical position. The system angle may be between about 20° and about 70° from a vertical position. The actuator may include a linear electromagnetic actuator. The system may also include a machine vision system including a camera configured to capture an image of the valve when the valve cycles between an open state and a closed state. The system may also include one or more lights, the one or more lights being coupled to the chamber assembly and configured to illuminate the valve. The system may also include a machine vision system including a camera configured to capture an image of the valve, and a light controller configured to illuminate the one or more lights at a rate associated with the actuation rate of the fluid displacement member. The system may also include a first pressure sensor configured to measure the liquid pressure in the proximal internal space, and a second pressure sensor configured to measure the liquid pressure in the distal internal space. The system may also include a flexible diaphragm disposed between the chamber assembly and the bellows, which separates the proximal internal space from the internal space of the displacement member. The actuator may include a rotary motor. The fluid displacement member may include a bellows. The fluid displacement member may include a rolling diaphragm. The flow area of ​​the one or more reflow orifices may be adjusted without removing the valve support from the chamber assembly. The system may also include an orifice actuator, which is configured to adjust the flow area of ​​the one or more reflow orifices in response to a signal from a control system at least in part. The distal chamber portion may be releasably attached to the proximal chamber portion. The valve support may be detachably disposed between the proximal internal space and the distal internal space. The system may be constructed for accelerated life testing of valves. The system may also include a liquid at least partially disposed within (i) the displacement member interior space, (ii) the proximal interior space, and (iii) the distal interior space. The system may also include an air space within the distal interior space.

[0010] In another embodiment, a method for controlling an accelerated life test system includes (i) receiving, via a computer controller of the system, an indication of an effective flow area of ​​a valve that cycles between an open state and a closed state under the action of the accelerated life test system, the effective flow area corresponding to the open state, wherein the indication of the effective flow area of ​​the valve is received from a machine vision system, the machine vision system including a camera that captures an image of the valve as the valve cycles between the open state and the closed state; (ii) comparing, via the computer controller, the indication of the effective flow area of ​​the valve with a threshold value; and (iii) adjusting, via the computer controller and based on the comparison, an actuator of the accelerated life test system, wherein the adjustment causes a change in the effective flow area of ​​the valve.

[0011] This method for controlling an accelerated life test system may optionally include one or more of the following features. The adjustment may include increasing or decreasing the amplitude of an input waveform to the accelerated life test system, wherein the input waveform is used to control the actuator. The method may also include adjusting the orifice size based on a pressure differential across the valve by a computer controller, wherein adjusting the orifice size causes a change in the pressure differential across the valve. The method may also include illuminating the valve, which may be performed based on the timing of the rate at which the valve cycles between an open state and a closed state.

[0012] In another specific implementation, a system for testing a valve includes a chamber assembly; one or more lights connected to the chamber assembly and configured to illuminate the valve; an oscillating fluid pump that defines an internal pump space that merges with the proximal internal space; an actuator that is configured to actuate the oscillating fluid pump at an actuation rate to adjust the internal pump space; and a control system that is configured to illuminate the one or more lights at a rate associated with the actuation rate. The chamber assembly includes a proximal chamber portion that defines a proximal internal space, a distal chamber portion that defines a distal internal space that merges with the proximal internal space, and a valve support disposed between the proximal internal space and the distal internal space, the valve support being configured to receive the valve in a hole of the valve support.

[0013] This system for testing a valve may optionally include one or more of the following features. The system may also include a camera configured to capture an image of the valve when the valve cycles between an open state and a closed state. The control system may include a machine vision system configured to determine the degree of opening of the valve when the valve is in an open state, and wherein the output from the camera is an input to the machine vision system. The control system may be configured to adjust the system in response to determining that the degree of opening of the valve is below a threshold. The valve stent may include one or more regurgitation orifices defining an open space so that the proximal interior space is fluidically connected to the distal interior space via the open space, and the control system may be configured to adjust the configuration of the open space in response to determining that the degree of opening of the valve is below a threshold. The chamber assembly may be a first chamber assembly, and the system may also include one or more additional chamber assemblies. The one or more additional chamber components each include: a proximal chamber portion defining a proximal interior space, a distal chamber portion defining a distal interior space that merges with the proximal interior space, and a valve support disposed between the proximal interior space and the distal interior space, the valve support being configured to receive a valve in a hole of the valve support. The first chamber assembly and the one or more additional chamber assemblies can each be controlled by a computer system. The valve support can be separated from the chamber assembly. The system can also include a diaphragm disposed between the chamber assembly and the oscillating fluid pump. The diaphragm can be configured to transmit fluid pressure between the chamber assembly and the oscillating fluid pump. A first liquid can be contained in the chamber assembly, and a second liquid different from the first liquid can be contained in the internal pump space. The valve support can be configured to receive a valve in a first orientation and a second orientation, the second orientation being rotated about 180 degrees from the first orientation.

[0014] In another specific implementation, a chamber assembly for testing a valve includes a proximal chamber portion defining a proximal interior space and a distal chamber portion defining a distal interior space. The distal interior space includes a gas space. When a liquid is inserted into the proximal chamber and the distal chamber, an interface between the liquid and the gas exists in the gas space. The valve support is disposed adjacent to the proximal interior space and the distal interior space. The valve support is configured to receive a valve in a hole of the valve support. When located in the hole, the shortest distance between the center of the valve and the interface is at least about 45 mm.

[0015] Embodiments may include one or more of the following features or any combination thereof. The shortest distance between the center of the valve and the interface when located in the hole is at least about 50 mm. The shortest distance between the center of the valve and the interface when located in the hole is at least about 55 mm. The shortest distance between the center of the valve and the interface when located in the hole is at least about 60 mm. The shortest distance between the center of the valve and the interface when located in the hole is at least about 65 mm. The interface area A when the liquid is at rest s(in cm) is set so that the stirred liquid depth D a The agitated liquid depth is the distance (in cm) below the interface reached by the agitated liquid containing bubbles during testing of the valve. The chamber assembly includes one or more baffles located in the distal interior space, at least partially on a first side of the interface and at least partially on a second side of the interface when the liquid is at rest. The one or more baffles reduce reflections of waves in the liquid from the sides of the distal chamber.

[0016] In another embodiment, a system for testing a valve includes a chamber assembly having a proximal chamber portion defining a proximal interior space and a distal chamber portion defining a distal interior space. The distal interior space includes a gas space. When a liquid is inserted into the proximal chamber and the distal chamber, an interface between the liquid and the gas exists in the gas space. A valve support is disposed adjacent to the proximal interior space and the distal interior space. The valve support is configured to receive a valve in a hole of the valve support. The interface area A when the liquid is at rest s (in cm) is set so that the stirred liquid depth D a Not greater than the distance from the interface to the valve top edge, where the agitated liquid depth is the distance (in cm) below the interface that the agitated liquid containing bubbles reaches during testing of the valve.

[0017] Embodiments may include one or any combination of the above and / or following features. s With D a The relationship between them is basically a =-mA s + b, wherein m is in the range of about -0.6 to about -2.2, and b is in the range of about 13.1 to about 20.8. A s With D a The relationship between them is basically a =-1.6A s +18.4.

[0018] In another specific implementation, a system for testing a valve includes a chamber assembly having a proximal chamber portion defining a proximal interior space and a distal chamber portion defining a distal interior space. The distal interior space includes a gas space. When a liquid is inserted into the proximal chamber and the distal chamber, an interface between the liquid and the gas exists in the gas space. One or more baffles are located in the distal interior space, at least partially on a first side of the interface and at least partially on a second side of the interface when the liquid is at rest. The one or more baffles reduce reflections of waves in the liquid from the sides of the distal chamber portion. A valve stent is disposed between the proximal interior space and the distal interior space. The valve stent is configured to receive a valve in a hole of the valve stent.

[0019] Embodiments may include one of the above features or any combination thereof.

[0020] Specific embodiments of the subject matter described herein can be implemented to achieve one or more of the following advantages. First, in some embodiments, the accelerated life test system provided herein can be operated at high speed. For example, in some embodiments, these systems can be operated at a frequency of about 30 Hz or higher. Therefore, compared with systems operating at lower speeds, the duration of the accelerated life test can be shortened. Second, in some embodiments, the test requirement that the transvalve ΔP is at least a specified pressure during at least 5% of the cycle can be met with a minimum ΔP overshoot. This feature can minimize valve overstress during the test. Such overstress can cause extremely harsh test conditions and can result in unrepresentative test results. Third, the pulsating flow system for accelerated life testing provided herein is configured to be convenient to use. For example, in some embodiments, portions of the test equipment can be removed from the pulsating flow system and installed on other test equipment in a user-friendly manner. Fourth, the system provided herein is configured to allow visual observation and analysis of the valve during the test. In some embodiments, this visual analysis can be performed using normal vision or using a camera such as, but not limited to, an automated machine vision system. Fifth, in some embodiments, the system provided herein is constructed to substantially replicate physiological conditions and / or meet ISO test requirements when using a standard sinusoidal input waveform. However, in some embodiments, non-sinusoidal waveforms may be used. Sixth, some aspects of the system (e.g., test chamber) are designed to be adjustable to provide fluid dynamics performance that meets user test requirements. That is, in some embodiments, the fluid dynamics performance of the system can be adjusted to achieve the desired performance by adjusting, for example, the size of the reflux orifice or the size of the air cavity. In addition, in some embodiments, a closed-loop control for automatic system adjustment during the test is included.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those of ordinary skill in the art to which the present invention belongs. Although methods and materials similar or equivalent to those described herein can be used to implement the present invention, suitable methods and materials are described herein. All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety. In the event of a conflict, this specification (including definitions) shall prevail. In addition, materials, methods and examples are merely exemplary and are not intended to be limiting.

[0022] The details of one or more embodiments of the invention are set forth in the drawings and the description herein. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a perspective view of an exemplary accelerated life testing system according to some embodiments.

[0024] Figure 2A yes Figure 1 Side view of the accelerated life test system.

[0025] Figure 2B yes Figure 1 Front view of the accelerated life test system.

[0026] Figure 3 yes Figure 1 Exploded side view of an accelerated life test system.

[0027] Figure 4A is a front view of an exemplary test chamber for an accelerated life testing system according to some embodiments.

[0028] Figure 4B yes Figure 4A Cross-sectional side view of the test chamber.

[0029] Figure 5 yes Figure 4B Exploded view of the test chamber.

[0030] Fig. 6A is an exploded side view of an exemplary valve support and prosthetic valve subassembly.

[0031] Figure 6B yes Fig. 6A Front view of the valve stent and prosthetic valve subassembly.

[0032] Figure 7 yes Figure 4B Side view of a test chamber shown partially filled with liquid and undergoing visual inspection.

[0033] Figure 8 yes Figure 1 Block diagram of the accelerated life test system.

[0034] Fig.9A is an exemplary input waveform that may be used in an accelerated life testing system according to some embodiments.

[0035] Fig. 9B are exemplary waveforms of test chamber pressure and test chamber pressure differential according to some embodiments.

[0036] Fig.10 is an isometric view of an exemplary portable portion of a test chamber including a valve support.

[0037] Fig.11 is a side view of another exemplary embodiment of a test chamber for an accelerated life testing system in accordance with some embodiments.

[0038] Fig.12 is a side view of another exemplary embodiment of a test chamber for an accelerated life testing system in accordance with some embodiments.

[0039] Fig.13 is a side view of another exemplary embodiment of a test chamber for an accelerated life testing system in accordance with some embodiments.

[0040] Fig.14 is a side view of another exemplary embodiment of a test chamber for an accelerated life testing system in accordance with some embodiments.

[0041] Fig.15 It is available for Fig.14 A perspective view of the baffle of the example shown in FIG. Like reference numerals refer to corresponding parts throughout. DETAILED DESCRIPTION

[0042] Systems and methods for testing various valves are provided herein. For example, systems and methods for accelerated life testing of prosthetic heart valves are provided herein.

[0043] See also Figure 1 , 2A 2B, an exemplary multi-station accelerated life test (ALT) system 100 includes a plurality of chambers 110, a frame 120, and a plurality of bellows 130. The chambers 110 and bellows 130 are mounted to and supported by the frame 120. Each individual chamber 110 is in fluid communication with a corresponding individual bellows 130 located below the individual chamber 110, or in some embodiments, a flexible film diaphragm 121 may be optionally used between the chamber 110 and the bellows 130. The bellows 130 may be axially stretched or compressed, as will be further described below.

[0044] The interior spaces of chamber 110 and bellows 130 may receive a liquid (e.g., saline, water, etc.). Thus, axial extension or compression of bellows 130 will induce corresponding movement of the liquid within bellows 130 and within chamber 110. For embodiments including optional flexible membrane diaphragm 121, such movement of bellows 130 causes a change in the pressure of the liquid contained in bellows 130, which is in communication with the liquid in chamber 110 via flexible membrane diaphragm 121. As will be further described below, a valve (e.g., a prosthetic heart valve) may be mounted within chamber 110. Axial actuation of bellows 130 may thus cause the liquid to flow through the valve, causing the valve to cycle between an open state and a closed state.

[0045] In the exemplary ALT system 100, six stations are included, each station including a separate chamber 110 and a corresponding separate bellows 130. In other system embodiments, fewer or more than six stations may be included. For example, in an alternative embodiment, the ALT system may include a single chamber 110 and a single corresponding bellows 130. In general, the ALT system 100 is scalable such that any practical number of test stations may be included.

[0046] See also Figure 3 , the ALT system 100 (shown in an exploded side view) may also include a linear actuator 140. The bottom end of the linear actuator 140 may be mounted to the frame 120, and the active end of the linear actuator 140 may be attached to the bellows 130. In some embodiments, a single linear actuator 140 may be configured to drive two or more bellows 130.

[0047] In some embodiments, the linear actuator 140 is an electromagnetic actuator that includes one or more stator coils and a flexible suspension element connected to each end of the armature of the actuator 140. The flexible suspension element allows the armature to move frictionlessly in the vertical direction of travel while providing resistance to the movement of other degrees of freedom of the armature (e.g., translation, rotation). During the operation of the electromagnetic actuator 140, the magnetic field from the magnetic assembly having one or more permanent magnets interacts with the magnetic field generated by the current flowing in the stator coil. This interaction causes the armature to move up and down linearly relative to the housing frame 120. In some embodiments, a displacement sensor 141 (e.g., LVDT, etc.) is optionally included to detect and acquire data related to the linear movement of the actuator 140. In some embodiments, the data output from the displacement sensor 141 can be used, for example, for closed-loop control of the actuator 140. In some embodiments, the displacement sensor 141 can be used as an indicator of piston movement, for example, or for indicating the fluid delivery of each cycle based on an established actuator and fluid volume relationship.

[0048] The linear motion of the actuator 140 in turn causes the axial expansion and compression of the bellows 130. The liquid inside the bellows 130 will be withdrawn from or pushed into the chamber 110 to which the bellows 130 is attached. This movement of the liquid can cause the opening and closing of the valve located within the chamber 110. In some embodiments, other types of fluid displacement members can replace the bellows 130 (e.g., a sliding piston or an undulating diaphragm, etc.). In some embodiments, other types of actuator devices can replace the linear electromagnetic actuator 140 (e.g., a rotary motor with a crank mechanism, etc.). Various combinations and sub-combinations of fluid displacement members and actuator devices are contemplated to be within the scope of the present invention.

[0049] See also Figure 4A , 4B and 5, the chamber 110 includes a distal chamber 111, a valve support 114, and a proximal chamber 118. When the chamber 110 is assembled, the valve support 114 is disposed between the distal chamber 111 and the proximal chamber 118. The end 119 of the proximal chamber 118 may be coupled to a bellows (e.g., the bellows 130 of the ALT system 100). In this case, the extension or compression of the bellows may draw or advance a volume of liquid relative to the chamber 110, such that the volume of liquid is transferred between the proximal chamber 111 and the distal chamber 118. In this case, the volume of liquid passes through the valve support 114. To facilitate the passage of liquid, the distal chamber 111 includes a compliant feature (e.g., as described below with reference to Figure 7 The air space 182 described herein, or another type of compliant feature, such as but not limited to a flexible member).

[0050] In some embodiments, the components of chamber 110 are made of polymer materials. For example, in some embodiments, the components of chamber 110 are made of polymer materials such as, but not limited to, polycarbonate (e.g., LEXAN), polyoxymethylene (e.g., DELRIN), acrylic, acetyl, PVC, etc. Such materials can be formed into a desired shape by processing, molding, 3D printing, and / or any other suitable process and combination of processes. In some embodiments, transparent or nearly transparent materials are used for the components of chamber 110 (e.g., at least proximal chamber 111 and distal chamber 118). Therefore, in some embodiments, the interior of chamber 110 can be advantageously visible. In some embodiments, three or more sides of the chamber 110 assembly are substantially transparent.

[0051] The distal chamber 111 is releasably coupled to the proximal chamber 118. In some embodiments, one or more latches, clamps, pins, hinges, threaded connections, bayonet-type connections, circumferential clamps, and / or other types of quick-release connection mechanisms are used to releasably couple the distal chamber 111 to the proximal chamber 118 in a convenient manner. Such a user-friendly mechanism for assembling and disassembling the chamber 110 may be desirable because at some time during valve durability testing, the chamber 110 may need to be disassembled so that other types of testing or inspections can be performed on the valve.

[0052] In the illustrated embodiment, the lens 112 is attached to the distal chamber 111. The lens 112 may be a transparent member, such as polycarbonate, tempered glass, etc. The lens 112 may provide a direct view of the valve located within the valve support 114. Although in the illustrated embodiment, the lens 112 is a separate component attached to the distal chamber 111, in other embodiments, the lens 112 may be integrally formed in the wall of the distal chamber 111.

[0053] In order to make the chamber 110 a liquid-tight closure, seals may be included at the interfaces between the components of the chamber 110. For example, seal 117 is located at the interface between the distal chamber 111 and the proximal chamber 118. In addition, seal 113 is located at the interface between the distal chamber 111 and the lens 112. One or more seals 116a and 116b may also be located around the periphery of the valve support 114. Seals 116a and 116b may inhibit paravalvular leakage between the distal chamber 111 and the proximal chamber 118. In some embodiments, one or more seals may also be located at the interface between the end 119 of the proximal chamber 118 and the bellows. The seal may be configured as an O-ring, a D-ring, a gasket, a washer, or the like, and may be made of materials such as, but not limited to, ethylene propylene diene monomer (EPDM), nitrile, silicone, fluorocarbon, polyurethane, neoprene, fluorinated ethylene propylene (FEP), or the like.

[0054] One or more ports 111p may be included in the distal chamber 111. Similarly, one or more ports 118p may be included in the proximal chamber 118. Such ports 111p and 118p may be used to access the interior open space defined by the chambers 111 and 118, respectively. The ports 111p and 118p may be used for various purposes, such as, but not limited to, draining fluid from the chambers 111 and 118, installing one or more sensors in the chambers 111 and 118, attaching a compliance chamber to the proximal chamber 118 and / or the distal chamber 111, and installing one or more lights to illuminate the interior of the chambers 111 and 118. For example, in some cases, the ports 111p and 118p may be used to install a pressure sensor that is used to monitor the pressure of the fluid in the chambers 111 and 118. Additionally, in some cases, the ports 111p and 118p may be used to install a light (e.g., an LED) that may be used to enhance viewing of the valve being tested. For example, as will be described further below, in some embodiments such a light may be used as a timing light so that high speed operation of a valve being tested may be viewed as if the valve were operating at a slower speed.

[0055] The proximal chamber 118 includes an inlet channel 118i. The inlet channel 118i transmits liquid between the bellows and the chambers 111 and 118. In some embodiments, the inlet channel 118i is configured to transmit a jet of liquid from the bellows to the proximal chamber 118, which flows substantially coaxially with the central axis of the valve support 114. In the illustrated embodiment, to achieve substantially coaxial flow, the radius and position of the inlet channel 118i are set so that the outer radius of the inlet channel 118i is roughly aligned with the axis of the central axis of the valve support 114. In some embodiments, other configurations of the inlet channel 118i associated with the valve support 114 can be used.

[0056] The valve support 114 includes a central hole 114b lined with a removable sleeve 115. The inner diameter of the sleeve 115 is configured to receive the valve body therein. The interface between the inner diameter of the sleeve 115 and the outer diameter of the valve body is intended to be substantially liquid-tight to avoid leakage around the valve during testing. Therefore, the sleeve 115 can be made of a compliant material. For example, in some embodiments, the sleeve 115 can be made of materials such as but not limited to silicone, neoprene and other suitable elastomers. In some embodiments, the inner diameter of the sleeve 115 may include circumferential grooves or other such surface features to facilitate the installation of the valve to be tested therein. In a specific embodiment, the inner diameter of the sleeve 115 can be designed to simulate the geometry (physiology) of the valve implantation site. In some embodiments, the sleeve 115 is compliant so that if the valve ΔP reaches an overpeak condition, the compliance can reduce the impact of this condition. That is, in some embodiments, the sleeve 115 is configured to flex in response to a high ΔP between the proximal and distal interior spaces of the chamber 110 .

[0057] See also Fig. 6A and 6B , the valve support 114 can receive an exemplary prosthetic heart valve 150 in the central hole 114b of the valve support 114. The valve 150 is a one-way valve. That is, liquid flowing in one direction relative to the valve 150 will open the valve 150 so that the liquid can flow therethrough (see, for example, Figure 4A and 4B , when the liquid flows from the proximal chamber 118 toward the distal chamber 111, the valve 150 will open). However, when the liquid begins to flow in the opposite direction relative to the valve 150, the valve 150 will close, so that the liquid will be prevented from flowing therethrough. Alternatively, in some embodiments, the valve 150 is installed in the opposite direction, so that the valve 150 will close when the liquid is transferred from the proximal chamber 118 to the distal chamber 111, and the valve 150 will be forced to open when the liquid is transferred from the distal chamber 111 to the proximal chamber 118.

[0058] In order to facilitate the liquid to flow through the valve support 114 in the direction that causes the valve 150 to close, the valve support 114 includes one or more reflow orifices 114ou and 114ol. In the illustrated embodiment, the reflow orifice 114ou is an upper orifice, and the reflow orifice 114ol is a lower orifice. In some embodiments, it may be advantageous to have an upper orifice 114ou and a lower orifice 114ol. For example, when some air (e.g., bubbles) is trapped in the proximal chamber 118, the upper orifice 114ou may facilitate the air flow to pass through it (e.g., as will be further described below, some trapped air may be better accommodated in the distal chamber 111). In addition, the lower orifice 114ol may facilitate the fluid to flow through it to facilitate the discharge of liquid from chambers 118 and 111 under the action of gravity. Therefore, in some embodiments, one or more regurgitation orifices are positioned on the valve support 114 so that at least the first regurgitation orifice of the one or more regurgitation orifices 114ou and 114ol is located in the upper portion of chambers 111 and 118, and at least the second regurgitation orifice of the one or more regurgitation orifices 114ou and 114ol is located in the lower portion of chambers 111 and 118.

[0059] Although the illustrated embodiment includes two regurgitant orifices 114ou and 114ol, in some embodiments, a single orifice or more than two orifices are included. For example, in some embodiments, the valve support 114 may include three, four, five, six, seven, eight, nine, ten or more than ten orifices.

[0060] In the illustrated embodiment, an interchangeable valve stent end plate 114p is included. In some embodiments, one purpose of the valve stent end plate 114p is to construct the valve stent 114 with a desired number of regurgitation orifices. In addition, in some embodiments, another purpose of the valve stent end plate 114p may be to construct the size of the one or more regurgitation orifices. Although in the illustrated embodiment, the regurgitation orifices 114ou and 114ol are located in the valve stent 114, it should be understood that in addition to or as an alternative, in some embodiments, the regurgitation orifice may be located in other structures of the chamber 110. For example, in some embodiments, the regurgitation path may be connected between ports 118p and 111p.

[0061] It should be understood that the number and size of the one or more return orifices (e.g., orifices 114ou and 114ol) affect the pressure differential between the proximal chamber 118 and the distal chamber 111 (see Figure 4A and 4B ). This pressure differential is also the pressure to which the valve 150 is exposed when the valve 150 is closed.

[0062] Briefly, the effect of the number and size of the one or more regurgitant orifices on the pressure differential is explained as follows. When the bellows 130 is compressed, a certain amount of fluid will be transferred across the open valve 150 (see, e.g., Figure 1 –3). Generally speaking, the ALT system will be constructed so that the amount of fluid to be transferred will be the amount required to fully open the valve. The aforementioned amount will need to return through the regurgitant orifices within a specific time period (the time the bellows 130 is extended). Therefore, a small total area of ​​the regurgitant orifices will produce a higher pressure differential, while a large total area of ​​the regurgitant orifice size will produce a lower pressure differential. In this way, the selection of the number and / or size of the regurgitant orifices can affect the pressure to which the valve 150 is exposed when the valve 150 is closed. In some embodiments, the flow area of ​​the one or more regurgitant orifices is selected based on the size of the valve 150 to be tested.

[0063] In some embodiments, the total area of ​​the return orifices can be adjusted without disassembling chamber 110 (see Figure 4A and 4B ). For example, in some embodiments, one or more regurgitant orifices may be configured as valve-like devices (e.g., gate valves, ball valves, needle valves, etc.) that can be adjusted outside of chamber 110. In some embodiments, the adjustment can be made manually, including while the test system is operating. In specific embodiments, the adjustment can be made automatically. In some such embodiments, a valve actuator and a control device may be included so that the total area of ​​the regurgitant orifices can be automatically adjusted to control toward a target operating parameter, such as (but not limited to): a pressure differential characteristic across valve 150 when valve 150 is closed (e.g., a peak pressure differential across valve 150 when valve 150 is closed).

[0064] See also Figure 7 In some embodiments, chamber 110 may be filled with liquid 180 and air space 182. Air space 182 is located in distal chamber 111 and in direct contact with liquid 180. Liquid 180 may be a liquid such as, but not limited to, water, saline, culture medium, etc. Air space 182 may be filled with a gas such as air, CO2, etc. While the volume of liquid 180 is substantially incompressible, the volume of air space 182 is compressible.

[0065] During operation of chamber 110, air space 182 is cyclically compressed and decompressed in sync with the cyclic action of bellows 130 (see Figure 4A and 4B). The cyclic compression and decompression of the air space 182 occurs as follows. As the bellows 130 compresses, some of the liquid 180 from the bellows 130 is expelled into the proximal chamber 118. The liquid 180 expelled into the proximal chamber 118 in turn causes the same amount of liquid 180 to flow through the valve 150 and the return orifice into the distal chamber 111. This flow of liquid 180 causes the valve 150 to open. The volume of the air space 182 is reduced by an equal amount due to the amount of liquid 180 flowing into the distal chamber 111. The above action continues until the bellows 130 ends its compression phase.

[0066] After the compression phase of the bellows 130, the bellows 130 begins to expand. As the bellows 130 expands, a certain amount of liquid 180 is drawn out of the chamber 110. In general, the same amount of liquid 180 that was displaced from the bellows 130 during its compression phase will be drawn out of the chamber 110 and back into the bellows 130 during the expansion phase of the bellows 130. This displacement of liquid 180 from the chamber 110 will result in an equal increase in the volume of the air space 182.

[0067] Based on the above description related to the liquid 180 and the air space 182, it should be understood that in some embodiments, the air space 182 functions like a gas spring. That is, the air space 182 is compressed during one part of the test cycle and expanded during another part of the test cycle.

[0068] It should also be understood that the nominal volume of the air space 182 will affect the force required by the bellows 130 to drive the liquid 180 during the compression phase of the bellows 130. For example, when the air space 182 is large, the bellows 130 will require less work to compress the air space 182 than when the air space 182 is small. This is so because, according to the ideal gas law, compressing a large air space 182 by the same volume results in a smaller increase in pressure in the air space 182 than compressing a small air space 182 by the same volume. The compressed air space 182 can also facilitate the flow of liquid 180 from the distal chamber 111 to the proximal chamber 118 via the return orifices 114ou and 114ol during the expansion of the bellows 130 (see Figure 6B ). The negative pressure gradient across the valve 150 during and after closure of the valve 150 is desired for functional testing of the valve 150. The positive pressure within the air space 182 and the negative pressure created by the expansion of the bellows 130 contribute to the negative pressure across the valve 150. In some cases, this can have the effect of reducing the amount of vacuum drawn by the bellows 130 during testing.

[0069] Using the above principles related to the air space 182, the volume of the air space 182 can be selected (as a factor) to provide the desired pressure operating range of the test system 100. For example, the maximum pressure that the liquid 180 will reach (at the end of compression of the bellows 130) is affected by the nominal size of the air space 182. The maximum pressure is at least partially defined by the change in volume of the air space 182 relative to the nominal size of the air space 182 throughout the compression stroke of the bellows 130 (e.g., a 1 ml volume change of a 2 ml air space 182 produces a greater pressure than a 2 ml volume change of a 20 ml air space 182). In some embodiments, the size of the air space 182 is set so that the maximum pressure of the liquid 180 is relatively consistent with the maximum pressure to which the valve being tested will be exposed in the expected use scenario. For example, the maximum pressure to which the aortic heart valve will be exposed is the systolic pressure (e.g., nominally about 120 mmHg to about 160 mmHg). Thus, in one example, the volume size of the air space 182 can be selected so that the maximum pressure of the liquid 180 during the contraction phase is about 150 mmHg. In other examples, other pressure levels can be designed by selecting the appropriate volume size of the air space 182.

[0070] In some embodiments, one or more heating elements (not shown) and one or more temperature sensors (not shown) are included to provide the ability to control and measure the liquid 180. Such heating elements and temperature sensors may be located in various locations, such as, but not limited to, near the interface between the end 119 of the proximal chamber 118 and the bellows. The heating elements and temperature sensors may also be positioned in other locations so that the temperature of the liquid 180 can be measured and / or controlled as desired.

[0071] Still see Figure 7 In the illustrated embodiment, the longitudinal axis 155 of the chamber 110 is inclined at an angle of about 35° from the horizontal position. In other embodiments, angles of about 0° to about 20°, or about 15° to about 35°, or about 30° to about 50°, or about 45° to about 65°, or about 60° to about 80°, or about 75° to about 90° may be used.

[0072] In some embodiments, the tilt of the longitudinal axis 155 provides some beneficial effects. For example, if any air is accidentally trapped in the liquid 180, the air tends to rise toward the air space 182 because the air space 182 is at the highest height in the chamber 110. If the accidentally trapped air is retained in the air space 182 rather than elsewhere in the chamber 110, the accidentally trapped air tends to have less negative impact on the test. For another example, the tilt of the longitudinal axis 155 allows both the top and bottom of the valve 150 to be observed. That is, as represented by the eye symbol 170, the bottom of the valve 150 can be observed through the end wall of the proximal chamber 118. In addition, the ergonomics associated with the viewing of the valve 150 benefit from the tilt of the longitudinal axis 155. In addition, as represented by the camera 160, the top of the valve 150 can be observed through the end wall of the distal chamber 118.

[0073] During testing, camera 160 can be used to view the operation of valve 150. Camera 160 can be a still frame camera or a video camera. In some embodiments, camera 160 is a high-speed camera. As previously described, in some embodiments, one or more lights are included for illuminating the interior of chambers 111 and 118 and valve 150. For example, in some embodiments, such lights can be used as timing lights so that high-speed operation of valve 150 when viewed by camera 160 appears as if the valve is operating at a slower speed.

[0074] In some embodiments, the camera 160 may be part of a machine vision system. In some such embodiments, the camera 160 and the machine vision system may be used to determine the extent to which the valve 150 is open during testing (e.g., the number of pixels corresponding to the flow area of ​​the valve 150 may be quantified). The extent of opening of the valve 150 (also referred to herein as the effective flow area) may be a parameter that needs to be verified during the execution of some durability testing protocols. In addition, by connecting the camera 160 and the machine vision system to the control system of the test system 100, closed-loop control using the machine vision system may be performed in some embodiments. For example, in some embodiments, the control system of the test system 100 may automatically adjust the operation of the test system 100 to reach a threshold level of the flow area of ​​the valve 150. In addition, it should be understood that such a machine vision system can be used to detect valve failure through user interaction or automatically through closed-loop control.

[0075] See also Figure 8, a control system 200 for an ALT system provided herein may include a computerized controller 210, a signal conditioner 220, a power supply 230 (which may include an amplifier stage in some embodiments), and an actuator and chamber assembly 240. The components of the control system 200 are in electrical communication with each other. That is, the components of the control system 200 may provide various outputs and receive various inputs from each other so that the overall control system 200 functions as desired. The components shown here, their connections and relationships, and their functions are intended to be exemplary only and are not intended to limit the embodiments of the invention described and / or claimed herein.

[0076] The control system 200 includes a computerized controller 210. The computerized controller 210 can be a digital computer in various forms, such as a laptop computer, a desktop computer, a workstation, a PLC, a server, a mainframe, a microcontroller, and other suitable computers and combinations of computers or computer components. The computerized controller 210 may include one or more processors, various formats of memory (volatile, non-volatile, hard disk, etc.), a GUI, various interfaces and communication devices and ports, etc. Such devices can be interconnected using various buses and can be installed on a common motherboard or installed in other ways as appropriate. The one or more processors can process instructions for execution within the computerized controller 210, including executable instructions stored in the memory.

[0077] The one or more processors of the computerized controller 210 can communicate with the user through a control interface and a display interface connected to a display device. The display device can be, for example, a TFT (thin film transistor liquid crystal display) display or an OLED (organic light emitting diode) display or other appropriate display technology. The display interface may include appropriate circuits for driving the display to present graphics and other information to the user. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and the input from the user can be received in any form, including sound input, voice input, or tactile input. The control interface can receive commands from the user and convert these commands for submission to the one or more processors. In addition, an external interface can provide communication with the one or more processors to enable the computerized controller 210 to communicate with other devices in the vicinity. The external interface can, for example, provide wired communication in some specific implementations, or provide wireless communication in other specific implementations, and multiple interfaces can also be used.

[0078] The control system 200 also includes a signal conditioner 220. The signal conditioner 220 can be configured to receive signals from a plurality of sensors (e.g., pressure or temperature sensors) and manipulate the signals for receipt by the computerized controller 210. For example, in some embodiments, the signal conditioner 220 can convert an analog signal input into a digital signal to be received by the computerized controller 210. Additionally, the signal conditioner 220 can perform other signal conversion activities, such as amplification, filtering, isolation, etc. Furthermore, in some embodiments, the signal conditioner 220 can receive input from the computerized controller 210 and then convert it for receipt by another device, such as a power supply 230 (which can include a power amplifier in some embodiments).

[0079] The control system 200 also includes a power supply 230. The power supply 230 provides electrical energy to the actuator and chamber assembly 240 to drive the actuator (e.g., Figure 3 For example, the power supply 230 may receive an input signal from the signal conditioner 220, and the power supply 230 may then amplify the signal and send it to the actuator and chamber assembly 240. In some embodiments, the signal may be a waveform (e.g., a sine wave or another shape). In some embodiments, the power supply 230 may also provide power to a liquid heater located in the actuator and chamber assembly 240.

[0080] The control system 200 also includes an actuator and chamber assembly 240. In some embodiments, for example, the actuator and chamber assembly 240 can be exemplified as the system 100 described above (see Figure 1 –3). The actuator and chamber assembly 240 may receive the above-mentioned inputs from the power supply 230 and may provide one or more outputs to the signal conditioner 220. For example, such outputs may include, but are not limited to, one or more of the following (see Figure 1 –7): pressure in the proximal chamber 118, pressure in the distal chamber 111, temperature of the liquid 180, displacement of the electromagnetic actuator 140, output from the camera 160 and the machine vision system indicating the degree of opening of the valve 150, etc. Such output signals can be received by the signal conditioner 220, converted if necessary, and passed to the computerized controller 210. The computerized controller 210 can use the output signals as parameters in the control algorithm run by the controller 210. The control algorithm can then generate an updated control signal, which can be output to the signal conditioner 220 as described above. In this way, the control system 200 can operate the ALT system in a controlled manner as needed. In some embodiments, each test chamber has its own microcontroller (as a slave system) for monitoring and controlling test parameters, and the microcontroller is connected to a master system (e.g., a laptop computer, etc.) that monitors the microcontroller at least periodically.

[0081] See also Fig.9A, an actuator displacement versus time graph 220 may illustrate an exemplary input waveform 222 that may be used with the system 100. The exemplary waveform 222 is substantially a sine wave. However, in some embodiments, other shapes of input waveforms 222 may be used. Furthermore, the cycle rates shown are examples only, and faster and slower cycle rates are contemplated to be within the scope of the present invention. Additionally, it should be understood that the amplitude, peak-to-valley values, and average values ​​of the wave signal are flexible and may be adjusted to achieve the desired pressure and volume flow conditions for the test.

[0082] Input waveform 222 indicates the movement of electromagnetic actuator 140, bellows 130, and flow of liquid 180 (see Figure 1-7 ). Now see Fig.9A and 9B As can be seen, the input waveform 222 causes corresponding fluctuations in the distal pressure curve 242, the proximal pressure curve 244, and the differential pressure curve 246. The distal pressure curve 242 represents the pressure of the liquid 180 in the distal chamber 111. The proximal pressure curve 244 represents the pressure of the liquid 180 in the proximal chamber 118. The differential pressure curve 246 represents the difference between the pressure 242 of the distal chamber 111 and the pressure 244 of the proximal chamber 118.

[0083] The fluctuations of pressure curves 242 and 244 can be briefly described as follows (see also Figure 1-7 ). The pressure curves 242 and 244 rise as the bellows 130 contracts axially. The axial compression of the bellows 130 forces a certain amount of liquid 180 to be discharged from the bellows 130 into the chamber 110. The flow of the liquid 180 in the direction from the proximal chamber 118 to the distal chamber 111 causes the valve 150 to open. Since the valve 150 is a relatively large opening, the pressure curves 242 and 244 rise substantially along the same curve, and the pressure difference curve 246 approaches zero. When the bellows 130 reverses and begins to expand axially, a certain amount of liquid 180 begins to be drawn back from the chamber 110 into the bellows 130. After the valve 150 is closed, the liquid 180 must flow through the one or more return orifices 114ou and 114ol. The one or more return orifices 114ou and 114ol are relatively small, so that when the liquid 180 flows through the one or more return orifices 114ou and 114ol, a significant pressure drop occurs in the proximal chamber 118. Therefore, the proximal pressure curve 244 (proximal chamber 118) drops below the distal pressure curve 242 (distal chamber 111), and the pressure difference curve 246 rises accordingly. The pressure difference curve 246 is the pressure on both sides of the valve 150 that changes with time.

[0084] According to the foregoing description, it should be understood that the pressure on both sides of the valve 150 is affected by the pressure drop of the liquid 180 when it flows through the one or more return orifices 114ou and 114ol. In addition, as described above, the pressure drop of the liquid 180 when it flows through the one or more return orifices 114ou and 114ol is affected by the size and number of the one or more return orifices 114ou and 114ol. Therefore, it is considered that the pressure on both sides of the valve 150 is affected by the size and number of the one or more return orifices 114ou and 114ol. In some specific implementations of the system 100, it is hoped that the physiological conditions in which the valve 150 will be used are basically replicated. Therefore, for the prosthetic heart valve 150, the size and number of the one or more return orifices 114ou and 114ol can be selected to establish a pressure difference curve 246 substantially as shown in the figure (when the valve 150 is open, the pressure on both sides of the valve 150 is substantially 0 mmHg, and when the valve 150 is closed, it is at least 100 mmHg for part of the time).

[0085] As described in the "Background Art", 5840-3:2013 requires that the pressure difference across the valve must be at least a specified pressure (eg, 100 mmHg for the aortic valve) during at least 5% of each cycle. Fig. 9B The enlarged portion of shows an example of how the pressure differential curve 246 relates to this requirement. In other words, during time period t1, the pressure differential curve 246 is at or above 100 mmHg (using the specified pressure of the aortic valve as an example), where time period t1 is at least 5% of each cycle time T. In some cases, during t1, the pressure differential curve 246 may exceed 100 mmHg, up to a maximum pressure differential p1. Generally speaking, it is desirable to have a pressure differential curve 246 where p1 is not significantly greater than 100 mmHg. This is so because when p1 is significantly greater than 100 mmHg, the stress to which the valve 150 is subjected exceeds the required value of ISO 5840:2005 (or as required by other applicable standards or related test conditions).

[0086] In some embodiments, the system 100 can be adjusted to produce a pressure differential curve 246 that (i) meets the requirement that the pressure differential across the valve must be at least a specified pressure (e.g., 100 mmHg for the aortic valve) during at least 5% of each cycle, and (ii) has a p1 that is not significantly greater than the specified pressure. This adjustment can be performed by selecting an appropriate combination of factors such as, but not limited to, the size and number of the one or more regurgitant orifices 114ou and 114ol, the cycle speed, the shape of the input waveform 222, the shape of the chamber 110, the volume of liquid 180 transferred during the cycle, the size and pressure of the air space 182, and positioning the one or more regurgitant orifices 114ou and 114ol between the distal chamber 118 and the proximal chamber 111 so that a short regurgitant path exists therebetween.

[0087] See also Fig.10 , the portable test chamber assembly 300 may include a distal chamber 111, a valve support 114, and a chamber cover 250. The portable test chamber assembly 300 may provide a convenient way to transport the valve and test chamber structure between various test stations (e.g., between a durability test device and a pulse repetition test device). In addition, the portable test chamber assembly 300 may allow the user to assemble the valve with the valve support 114 and with the distal chamber 111, and then store the assembly by attaching the chamber cover 250. In some cases, liquid may be added so that the valve can be immersed in the liquid during transportation or storage. By using the portable test chamber assembly 300, more efficient establishment and management of the overall testing process can be obtained. In some embodiments, the chamber assembly 300 can be used for static cultivation of valves seeded with cells until the cells / structure are in a state where the tissue can withstand a certain mechanical load. In some embodiments, the chamber assembly 300 can be used to allow simulation of surgical implantation of, for example, a transcatheter valve or similar valve.

[0088] See also Fig.11 , an exemplary cylindrical test chamber 400 embodiment may include a base 402, a proximal chamber 410, a distal chamber 420, a valve support 430, and an air space 440. The cylindrical test chamber 400 is configured to be compatible with other related components of the system 100 such as the frame 120, the bellows 130, and the actuator 140 (see Figure 3 ). The cylindrical test chamber 400 has a cylindrical chamber shape (whereas the chamber 110 has a three-dimensional rectangular shape). Although in the illustrated embodiment, the cylindrical test chamber 400 is arranged vertically, in some embodiments, the cylindrical test chamber 400 may be tilted as described above for the chamber 110. The cylindrical test chamber 400 may also include one or more of the other features described above for the chamber 110.

[0089] See also Fig.12, an exemplary hexagonal test chamber 500 embodiment may include a base 502, a proximal chamber 510, a distal chamber 520, and a valve support 530 (when the hexagonal test chamber 500 contains a liquid, the distal chamber 520 may include an air space). The hexagonal test chamber 500 is configured to be compatible with other related components of the system 100 such as the frame 120, the bellows 130, and the actuator 140 (see Figure 3 ). Hexagonal test chamber 500 has a three-dimensional hexagonal chamber shape (whereas chamber 110 has a three-dimensional rectangular shape). In the illustrated embodiment, hexagonal test chamber 500 is tilted as described above for chamber 110. Hexagonal test chamber 500 may also include one or more of the other features described above for chamber 110.

[0090] Go to Fig.13 , the exemplary test chamber 600 includes a proximal chamber portion 610 defining a proximal interior space and a distal chamber portion 620 defining a distal interior space. A valve support 630 is disposed between and adjacent to the proximal interior space and the distal interior space. The valve support 630 is configured to receive a valve 635 in a hole of the valve support. When the chambers 610 and 620 contain liquid, the distal interior space of the distal chamber 620 includes an air or gas space 640. An interface 650 between the liquid and the gas exists in the gas space. When located in the hole, the shortest distance 660 between the center of the valve 635 and the interface 650 is at least about 45 mm. For another example, when located in the hole, the shortest distance 660 between the center of the valve 635 and the interface 650 is at least about 50 mm. For another example, when located in the hole, the shortest distance 660 between the center of the valve 635 and the interface 650 is at least about 55 mm. In yet another example, when located in the hole, the shortest distance 660 between the center of the valve 635 and the interface 650 is at least about 60 mm. In yet another example, when located in the hole, the shortest distance 660 between the center of the valve 635 and the interface 650 is at least about 65 mm.

[0091] The area A of the interface 650 when the liquid is at rest s (in cm 2 The meter) is set so that the stirred liquid depth D a No greater than the distance 670 from the interface to the top edge of the valve 635. The stirred liquid depth D a A is the distance (in cm) that the stirred liquid containing bubbles reaches below the interface during the test of the valve. s With D a The relationship between them is basically a =-mA s + b (linear formula), wherein m is in the range of about -0.6 to about -2.2, and b is in the range of about 13.1 to about 20.8. In a specific example, As With D a The relationship between them is basically a =-1.6A s +18.4. The test chamber 600 is configured to be compatible with other related components of the system 100 such as the frame 120, bellows 130, and actuator 140 (see Figure 3 ) are used together. Test chamber 500 may also include one or more of the other features described above for chamber 110.

[0092] During testing, the liquid / gas surface / interface can become highly agitated. One cause of this is surface waves that reflect around the test chamber. While these waves should not affect the net velocity of the surface (assuming the liquid is incompressible and the chamber walls are rigid), this does increase the normal velocity of the surface at multiple locations. Placing walls (baffles) in the area of ​​the liquid / gas interface reduces the ability of these waves to reflect and also minimizes sloshing.

[0093] Go to Fig.14 , the exemplary test chamber 700 includes a proximal chamber portion 710 defining a proximal interior space and a distal chamber portion 720 defining a distal interior space. A valve support 730 is disposed between the proximal interior space and the distal interior space. The valve support 730 is configured to receive a valve in a hole of the valve support. When chambers 710 and 720 contain a liquid 745, an air or gas space 740 is included in the distal interior space. An interface 750 between the liquid 745 and the gas exists in the gas space 740. At least one baffle 760 is located in the distal interior space, at least partially on a first side of the interface when the liquid 745 is in a static state and at least partially on a second side of the interface. The baffle reduces reflections of waves in the liquid 745 from the sides of the distal chamber portion 720.

[0094] Fig.15 760 is shown in greater detail. In this example, the baffle is in the form of a honeycomb having an array of through holes that communicate liquid 745 and gas with each other. Of course, the baffle 760 may take other forms, such as curved walls or straight walls. A set of six tabs 770 protrude from the top surface of the baffle 760, away from the substantially horizontal top surface (or top) 780 of the distal chamber portion (see Fig.14 ) a smaller distance.

[0095] Although this specification contains many specific implementation details, it should not be understood as a limitation on the scope of any invention or the scope that may be claimed, but rather as a description of features that may be unique to a specific embodiment of a specific invention. Certain features described in this specification in the context of a separate embodiment may also be implemented in combination in a single embodiment. Conversely, the various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable sub-combination. In addition, although features may be described herein as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination may be deleted from the combination in some cases, and the claimed combination may be directed to a sub-combination or a variation of a sub-combination.

[0096] Similarly, although the operations are depicted in a particular order in the accompanying drawings, this should not be understood as requiring the operations to be performed in the particular order shown or in a sequential order, or requiring the execution of all the operations shown to achieve the desired results. In some cases, multitasking and parallel processing may be advantageous. In addition, the separation of various system modules and components in the embodiments described herein should not be understood as requiring this separation in all embodiments, and it should be understood that the program components and systems described can generally be integrated together in a single product or packaged into multiple products.

[0097] Specific embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. For example, the actions described in the claims can be performed in a different order and still achieve the desired results. As an example, the processes depicted in the accompanying drawings do not necessarily require the specific order shown, or sequential order, to achieve the desired results. As another example, test parameters can be controlled by selecting any monitored parameter (e.g., actuator displacement 222, proximal pressure 244, distal pressure 242, pressure gradient 246, air space 182, and others) as an independent parameter and adjusting the remaining dependent parameters accordingly. In certain implementations, multitasking and parallel processing may be advantageous.

Claims

1. A method for controlling an accelerated life test system, the method comprising: receiving, by a computer controller of the system, an indication of an effective flow area of ​​a valve cycled between an open state and a closed state under the accelerated life testing system, the effective flow area corresponding to the open state, wherein the indication of the effective flow area of ​​the valve is received from a machine vision system, the machine vision system including a camera that captures an image of the valve as the valve cycles between the open state and the closed state; comparing, by the computer controller, the indication of the effective flow area of ​​the valve to a threshold value; as well as An actuator of the accelerated life testing system is adjusted, by the computer controller, based on the comparison, wherein the adjustment causes a change in the effective flow area of ​​the valve. 2 . The method of claim 1 , wherein the adjusting comprises increasing or decreasing the amplitude of an input waveform to the accelerated life testing system, wherein the input waveform is used to control the actuator.

3. The method of claim 1 , further comprising adjusting an orifice size by the computer controller based on a pressure differential across the valve, wherein the adjusting the orifice size causes a change in the pressure differential across the valve. The method of claim 1 , further comprising illuminating the valve. 5 . The method of claim 4 , wherein the illumination of the valve is performed at a timing based on a rate at which the valve cycles between the open state and the closed state.

6. A chamber assembly for testing a valve, the chamber assembly comprising: a proximal chamber portion defining a proximal interior space; a distal chamber portion defining a distal interior space, the distal interior space including a gas space, wherein when a liquid is inserted into the proximal chamber and the distal chamber, an interface between the liquid and the gas exists in the gas space; as well as A valve support is arranged adjacent to the proximal internal space and the distal internal space, and the valve support is constructed to receive the valve in the hole of the valve support, wherein when located in the hole, the shortest distance between the center of the valve and the interface is at least 45mm.

7. The chamber assembly of claim 6, wherein the shortest distance between the center of the valve and the interface when located in the aperture is at least 50 mm.

8. The chamber assembly of claim 6, wherein the shortest distance between the center of the valve and the interface when located in the aperture is at least 55 mm.

9. The chamber assembly of claim 6, wherein the shortest distance between the center of the valve and the interface when located in the aperture is at least 60 mm.

10. The chamber assembly of claim 6, wherein the shortest distance between the center of the valve and the interface when located in the aperture is at least 65 mm.

11. The chamber assembly of claim 6, wherein the area A of the interface in cm when the liquid is at rest s is set so that the stirred liquid depth D a Not greater than the distance from the interface to the top edge of the valve, wherein the agitated liquid depth is the distance in cm that the agitated liquid containing bubbles reaches below the interface during testing of the valve.

12. The chamber assembly of claim 11 further comprising one or more baffles positioned in the distal interior space, at least partially on the first side of the interface and at least partially on the second side of the interface when the liquid is at rest, the one or more baffles reducing reflections of waves in the liquid from the sides of the distal chamber.

13. The chamber assembly according to claim 6 further includes one or more baffles, which are located in the distal interior space and at least partially on the first side of the interface and at least partially on the second side of the interface when the liquid is in a static state, and the one or more baffles reduce the reflection of waves in the liquid from the sides of the distal chamber portion.

14. A system for testing a valve, the system comprising: A chamber assembly, the chamber assembly comprising: a proximal chamber portion defining a proximal interior space; a distal chamber portion defining a distal interior space, the distal interior space including a gas space, wherein when a liquid is inserted into the proximal chamber and the distal chamber, an interface between the liquid and the gas exists in the gas space; and A valve support disposed adjacent to the proximal interior space and the distal interior space, the valve support being configured to receive the valve in a hole of the valve support, wherein the area A of the interface in cm when the liquid is at rest s is set so that the stirred liquid depth D a Not greater than the distance from the interface to the top edge of the valve, wherein the agitated liquid depth is the distance in cm that the agitated liquid containing bubbles reaches below the interface during testing of the valve.

15. The system of claim 14, wherein the shortest distance between the center of the valve and the interface when located in the hole is at least 50 mm.

16. The system of claim 14, wherein the shortest distance between the center of the valve and the interface when located in the aperture is at least 55 mm.

17. The system of claim 14, wherein the shortest distance between the center of the valve and the interface when located in the hole is at least 60 mm.

18. The system of claim 14, wherein the shortest distance between the center of the valve and the interface when located in the aperture is at least 65 mm.

19. The system according to claim 14 further includes one or more baffles, which are located in the distal interior space and at least partially on the first side of the interface and at least partially on the second side of the interface when the liquid is in a static state, and the one or more baffles reduce the reflection of waves in the liquid from the sides of the distal chamber portion.

20. The system of claim 14, wherein A s With D a The relationship between them is basically D a =-mA s +b, wherein m is in the range of -0.6 to -2.2, and b is in the range of 13.1 to 20.

8.

21. The system of claim 20, wherein A s With D a The relationship between them is basically D a =-1.6A s +18.

4.

22. A system for testing a valve, the system comprising: A chamber assembly, the chamber assembly comprising: a proximal chamber portion defining a proximal interior space; a distal chamber portion defining a distal interior space, the distal interior space including a gas space, wherein when a liquid is inserted into the proximal chamber and the distal chamber, an interface between the liquid and the gas exists in the gas space; one or more baffles located in the distal interior space, at least partially on a first side of the interface and at least partially on a second side of the interface when the liquid is at rest, the one or more baffles reducing reflections of waves in the liquid from sides of the distal chamber portion; and A valve support is disposed between the proximal interior space and the distal interior space, and the valve support is configured to receive the valve in a hole of the valve support.

23. The chamber assembly of claim 22, wherein the shortest distance between the center of the valve and the interface when located in the aperture is at least 50 mm.

24. The chamber assembly of claim 22, wherein the shortest distance between a center of the valve and the interface when located in the aperture is at least 55 mm.

25. The chamber assembly of claim 22, wherein the shortest distance between a center of the valve and the interface when located in the aperture is at least 60 mm.

26. The chamber assembly of claim 22, wherein the shortest distance between a center of the valve and the interface when located in the aperture is at least 65 mm.

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