A fixture and a device for testing the force on a retrieved implant

Abstract

The present invention discloses a fixture, a device and a method for testing the force received during the recovery of an implant. The fixture includes a support portion, and mounting edges and clamping edges provided at both ends of the support portion. The three enclose to form a test cavity for accommodating the implant to be tested. A through stepped hole is provided in the mounting edge. The stepped hole allows the proximal end of the conveying device to extend into and be limited in the test cavity. The proximal end is used to connect the implant to be tested. The clamping edge is located on the opposite side of the mounting edge and can be connected to the first clamping end of the force measuring device. The device for testing the force received during the recovery of the implant includes a force measuring device and a fixture. The testing method is based on this device. The fixture provided by the present invention can be a test platform for subsequently measuring the force between the implant implanted through a catheter and the catheter during recovery, which is convenient to operate and has high accuracy. The device can simulate in vitro the force received by the implant when it is recovered into the delivery system in vivo, facilitating the evaluation of the safety of the implant being recovered into the delivery system and providing a basis for the design and optimization of the delivery system.

Description

Technical Field

[0001] The present invention relates to the technical field of testing devices, and particularly to a device for testing the force on an implant during recovery by a fixture. Background Art

[0002] With the advent of aging, more and more elderly people suffer from structural heart diseases, among which valvular diseases account for a large proportion. Due to factors such as the physical recovery of the elderly, it is difficult for them to withstand major traumatic surgeries. Therefore, transcatheter valve replacement surgeries with less trauma and faster recovery are favored by experts and the medical community. An implant (heart valve) is sent to the diseased location through a delivery system (such as a sheath) via a human blood vessel or the apex of the heart to replace the original valve and play its functional role.

[0003] Currently, a variety of transcatheter valve replacement products have been developed or marketed both at home and abroad, which can be sent to the native valve through a delivery system for implantation. During implantation, doctors mainly rely on preoperative CT evaluation and intraoperative imaging technology for determination. Due to the complexity of the human heart structure, the implantation position or specification of the heart valve often does not meet the expected determination. It is necessary to readjust the position of the heart valve or withdraw the heart valve with an inappropriate specification from the human body and reselect a suitable valve for implantation. Therefore, technical personnel have developed a retrievable heart valve. When the above problems occur, the heart valve is retrieved into the sheath through the delivery system for other corresponding post - processing.

[0004] Most of the frameworks of existing transcatheter heart valves are made of nickel - titanium alloy or cobalt - chromium alloy with shape - memory effect as raw materials, and are processed through a series of processes such as laser cutting, weaving, and heat treatment for shaping, so that they expand in the human body to replace the original valve. After the valve framework made of nickel - titanium alloy or cobalt - chromium alloy expands in the body, it no longer has the condition of being retracted into the loading sheath with the help of a crimping auxiliary tool as in the case of in - vitro loading. It can only be retracted into the loading sheath through the control handle of the delivery system, but this will cause the outflow end of the heart valve to squeeze against the proximal end of the loading sheath, generating a resistance that hinders the heart valve from being retracted into the loading sheath. Once the resistance is too large, it may not only cause the heart valve to fall off and slide into the heart, but also cause the proximal end of the loading sheath to deform or break, making it impossible to withdraw it from the body. If the sheath fragments fall inside the heart, it may also be accompanied by the internal support metal frame of the sheath breaking through the sheath and scratching the internal tissues, which will violate the original intention of choosing transcatheter surgery and require thoracotomy.

[0005] Currently, there is no special device for detecting the force on the valve when it is retracted into the sheath in the expanded state in vitro, which is not conducive to later evaluation and improving the corresponding structure of the delivery system and product material selection problems to ensure the safety of the surgery. Summary of the Invention

[0006] To overcome at least to some extent the problems existing in the related art, one of the purposes of the present application is to provide a fixture, which can provide a simulated environment for in-vivo recovery of an implant and a delivery system, so as to improve the accuracy and reliability of test data;

[0007] Another purpose of the present application is to provide a device for testing the force on an implant during recovery, which can test the force magnitude between the implant and the proximal end of the delivery system when the retrievable implant is retrieved into the delivery system, facilitating the evaluation of the safety of retrieving the implant into the delivery system and providing a basis for the design and optimization of the delivery system.

[0008] Another purpose of the present invention is to provide a method for testing the force on an implant during recovery in vitro using the above device. By using this method, the state changes of the proximal end of the loading sheath tube and the implant during implant recovery can be obtained qualitatively or quantitatively, providing a basis for the design and optimization of the delivery system. The specific technical solutions are as follows:

[0009] According to the first aspect of the embodiments of the present application, a fixture is provided, including a support portion, and a mounting edge and a clamping edge provided at both ends of the support portion. The mounting edge, the support portion, and the clamping edge enclose a test cavity for accommodating the implant to be tested;

[0010] A through stepped hole is provided on the mounting edge, and the proximal end of the delivery device can extend into and be limited in the test cavity through the stepped hole. The proximal end is used to connect the implant to be tested;

[0011] The clamping edge is located on the opposite side of the mounting edge and can be connected to the first clamping end of the force measuring device.

[0012] As an implementable manner, a body temperature simulation container is provided in the test cavity.

[0013] As an implementable manner, the delivery device includes a coupling structure and a loading sheath tube sleeved on the proximal end of the coupling structure. The proximal end of the coupling structure is connected to the implant;

[0014] The stepped hole includes a first hole and a second hole arranged in sequence. The first hole is located at the distal end of the stepped hole, and the diameter of the first hole is adapted to the diameter of the loading sheath tube. The diameter of the second hole is smaller than the diameter of the loading sheath tube and is adapted to the diameter of the coupling structure, so that the coupling structure penetrates through the second hole and extends to the first hole to be connected to the implant. When the distal end of the coupling mechanism is stretched, the loading sheath tube is limited in the first hole.

[0015] Preferably, the depth of the first hole is smaller than the length of the loading sheath tube.

[0016] As an implementable manner, the axis of the stepped hole has an included angle α with the mounting edge, and the value range of the included angle α is greater than 40° and less than 140°.

[0017] As an implementable manner, the telecentric end of the coupling structure is connected to the second clamping end of the force measuring device, wherein the second clamping end is disposed opposite to the first clamping end.

[0018] As an implementable manner, a carrier platform is provided on the clamping edge and is received in the test cavity. A connecting portion protruding away from the test cavity is further provided on the clamping edge, and the connecting portion is connected to the first clamping end of the force measuring device;

[0019] Preferably, the carrier platform is used to carry the body temperature simulation container;

[0020] Preferably, the carrier platform is welded or assembled with nuts on the clamping edge;

[0021] Further, the connecting portion is a plate, the first clamping end has a chuck, and the plate can be clamped on the chuck;

[0022] Preferably, the connecting portion is embedded in the first clamping end, a through fixing hole is opened at the free end of the connecting portion, and a connecting pin can be inserted into the fixing hole to be fixed on the first clamping end.

[0023] As an implementable manner, the supporting portion is a pair of columns, and the columns, the mounting edge and the clamping edge enclose to form the test cavity.

[0024] Preferably, the connection manner of the supporting portion with the mounting edge and the clamping edge is one or several of threaded connection, snap-fit connection, welding or adhesive connection.

[0025] Further, the supporting portion is fixedly connected to the mounting edge through a first bolt. The other end of the supporting portion has an axially opened groove, and mounting holes corresponding to each other are opened on both side walls of the groove. After the connecting edge is snap-fitted into the groove, it is fixedly connected to the column through a second bolt.

[0026] Furthermore, the mounting edge can be fixed at different height positions of the supporting portion;

[0027] Still further, a plurality of axially arranged threaded holes are opened on the side surface of one end of the supporting portion, and the mounting edge can be fixed at different height positions of the supporting portion by being installed in the threaded holes at different positions;

[0028] The installation directions of the first bolt and the second bolt on the supporting portion are perpendicular to each other.

[0029] According to a second aspect of the embodiments of the present application, a device for testing the force on a retrieved implant is provided. The device includes:

[0030] A force measuring device, the force measuring device having a force applying unit providing a first clamping end and a second clamping end, and a back-and-forth movement being possible between the first clamping end and the second clamping end;

[0031] The fixture is used to place the implant to be tested connected to the proximal end of the conveying device in the test cavity. The clamping edge of the fixture is connected to the first clamping end, and the distal end of the conveying device is connected to the second clamping end;

[0032] The force measuring device tests the condition of retrieving the implant to be tested into the conveying device through the back-and-forth movement.

[0033] As an implementable manner, the force measuring device further includes a test unit and a calculation and output unit connected by signals. The test unit is installed at the first clamping end / second clamping end, and is used to detect the magnitude of the force and send the detected data to the calculation and output unit. The calculation and output unit is used to display the detected data;

[0034] Preferably, the force measuring device is a tensile testing machine;

[0035] Preferably, the test unit is a sensor;

[0036] Further, the sensor is a force-sensitive element.

[0037] As an implementable manner, the force measuring device is a tensile testing machine.

[0038] Preferably, the test unit is a sensor. Further, the sensor is a force-sensitive element.

[0039] As an implementable manner, the first clamping end further includes a connecting cylinder, and a radially extending through hole is provided at the free end of the connecting cylinder; the connecting portion is a columnar object adapted to the connecting cylinder, and a through fixing hole is provided at the free end of the connecting portion. When the connecting portion is installed in the connecting cylinder, the through hole corresponds to the fixing hole, and the connecting portion is fixed to the first clamping end by a connecting pin passing through the through hole and the fixing hole.

[0040] Another object of the present invention is to provide a method for in vitro testing the force on a retrieved implant using the device, including the following steps:

[0041] Insert the proximal end of the coupling structure into the loading sheath and connect the implant to be tested to form a test part;

[0042] The distal center end of the coupling structure in the test part is sequentially passed through the first hole and the second hole of the fixture and then connected to the second holding end;

[0043] The connecting part of the clamping edge in the fixture is installed on the first clamping end;

[0044] Start the force measuring device to move the second clamping end away from the first clamping end;

[0045] Observe the morphological changes of the proximal center end of the loading sheath and the implant to be tested for qualitative evaluation.

[0046] Preferably, the first clamping end / the second clamping end is further provided with a test unit, and the test unit is signal-connected to a calculation and output unit, and quantitative evaluation can also be performed according to the output data of the calculation and output unit during observation.

[0047] The technical solution provided by the embodiment of the present application has at least the following beneficial effects:

[0048] Based on the setting of the stepped hole, the fixture of the present application can enable the proximal center end of the conveying device to extend into the test cavity, that is, place the implant in the test environment. At the same time, when recovering the implant into the conveying device to test the stress, the stepped hole can play an axial limiting role on the conveying device, so that the proximal center end of the conveying device cannot withdraw from the test cavity and is limited at the stepped hole, so as to smoothly realize the recovery of the implant. The fixture has opposite clamping edges and mounting edges, and can limit the conveying device on the mounting edge during the recovery process. By connecting one end of the conveying device to the force measuring device and connecting the clamping edge to the other end of the conveying device, the tensile force test experiment is completed.

[0049] The device for testing the recovery force of the implant in the present application can be used to provide the magnitude of the force for judging the heart valve to be received into the loading sheath of the conveying device without auxiliary tools in the expanded state. By installing the above fixture on a force measuring device (such as a tensile testing machine) for use, it can simulate the force magnitude of the implant (such as a heart valve) received into the loading sheath in the body in vitro. Since the test cavity is in a through state, it is possible to observe whether there is damage to the implant (such as a heart valve) and the loading sheath of the conveying device during the experiment, so as to judge the safety of the recoverable performance of the heart valve.

[0050] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. Description of the Drawings

[0051] The drawings here are incorporated into the specification and constitute a part of the specification, showing the embodiments in line with the present application, and are used together with the specification to explain the principles of the present application.

[0052] Figure 1 Structural schematic diagram of the fixture provided by an embodiment of the present invention;

[0053] Figure 2 Perspective view of the mounting edge provided by an embodiment of the present invention;

[0054] Figure 3 Cross-sectional view of the mounting edge provided by an embodiment of the present invention;

[0055] Figure 4 Side view of the column provided by an embodiment of the present invention;

[0056] Figure 5 Front view of the column provided by an embodiment of the present invention;

[0057] Figure 6 Structural schematic diagram of the clamping edge provided by an embodiment of the present invention;

[0058] Figure 7 Schematic diagram of the connection relationship of the coupling structure, loading sheath and implant provided by an embodiment of the present invention;

[0059] Figure 8 Schematic diagram of the connection relationship between the fixture, the delivery device and the implant provided by an embodiment of the present invention;

[0060] Figure 9 Schematic diagram of the use state of the device for testing the force received by the retrieval of the test implant provided by an embodiment of the present invention.

[0061] Explanation of reference numerals:

[0062] 100, test chamber;

[0063] 200, mounting edge; 210, stepped hole; 211, first hole; 212, second hole;

[0064] 300, clamping edge; 310, carrier table; 311, body temperature simulation container; 320, connecting part;

[0065] 400, support part; 410, threaded hole; 420, groove;

[0066] 500, delivery device; 510, coupling structure; 520, loading sheath;

[0067] 600, implant;

[0068] 700, force measuring device; 710, force applying unit; 711, first clamping end; 712, second clamping end; 720, testing unit; 730, calculation and output unit.

[0069] Among them, Figure 7The stretching direction of the force measuring device is shown by the double-headed arrow in the middle. Detailed implementation manners

[0070] Here, the exemplary embodiments will be described in detail, and the examples are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present application. On the contrary, they are merely examples of methods consistent with some aspects of the present application as detailed in the appended claims.

[0071] In the related art, when the heart valve implanted in the body needs to be retrieved and re-implanted due to inappropriate position, there is currently no force analysis of the heart valve and the loading sheath during the retrieval process, nor a corresponding device. Based on the premise that a pressing tool cannot be used for in-vivo retrieval, the outflow end of the heart valve and the proximal end of the loading sheath will squeeze each other, generating a resistance that hinders the heart valve from being retracted into the loading sheath. The magnitude of this resistance is not clear, which may cause the heart valve to fall off and slip into the heart, or the proximal end of the loading sheath to deform or break.

[0072] Based on the analysis and discovery of the above problems, the present application is proposed.

[0073] The present application provides a fixture, including:

[0074] A support portion, and mounting edges and clamping edges provided at both ends of the support portion. The mounting edges, the support portion, and the clamping edges enclose a test cavity for providing accommodation for the implant to be tested;

[0075] A through stepped hole is provided on the mounting edge. The stepped hole can allow the proximal end of the delivery device to extend into and be limited in the test cavity. The proximal end is used to connect the implant to be tested;

[0076] The clamping edge can be connected to the first clamping end of the force measuring device.

[0077] Based on the design of the stepped hole, the fixture of the present application can allow the proximal end of the delivery device to extend into the test cavity. At the same time, when testing the force during the retrieval of the implant into the delivery device, the stepped hole can play an axial limiting role on the delivery device, preventing the proximal end of the delivery device from withdrawing from the test cavity and limiting it at the stepped hole, so as to smoothly realize the retrieval of the implant. The fixture has opposite clamping edges and mounting edges, and can limit the delivery device on the mounting edge during the retrieval process. By connecting one end of the delivery device to the force measuring device and the other end of the delivery device to the clamping edge, it is possible to simulate the force on the implant when it is retrieved into the delivery system at human body temperature, and then improve the structural and material selection problems of the delivery system, ensuring the safety of the operation.

[0078] In some alternative embodiments, the delivery device includes a coupling structure and a loading sheath sleeved on the proximal end of the coupling structure. The proximal end of the coupling structure is connected to the implant. The loading sheath extends into the test chamber through the stepped hole for retrieving the implant. Wherein, the stepped hole includes a first hole and a second hole arranged in sequence. The first hole is located at the distal end of the stepped hole, and the diameter of the first hole is adapted to the diameter of the loading sheath. The diameter of the second hole is smaller than the diameter of the loading sheath and is adapted to the diameter of the coupling structure, so that the coupling structure penetrates through the second hole and extends to the first hole to be connected to the implant. When the distal end of the coupling mechanism is stretched, the loading sheath is limited in the first hole. In these embodiments, the coupling structure functions as a control handle, and the implant can be retrieved into the loading sheath through an external stretching action. Based on the fact that the diameter of the first hole near the test chamber is adapted to the diameter of the loading sheath, the first hole is used to extend the loading sheath, providing a certain radial supporting force for the loading sheath to ensure vertical force. The diameter of the second hole is smaller than the diameter of the loading sheath, so the second hole will have a certain obstructive effect on the distal end of the loading sheath during the retrieval process, facilitating the implant to be received into the loading sheath. Preferably, the depth of the first hole is smaller than the length of the loading sheath. When the depth of the first hole is set to be smaller than the length of the loading sheath, that is, the end of the loading sheath protrudes from the first hole. During the retrieval of the implant, the experimenter can visually observe whether there is damage to the loading sheath and the implant, thereby evaluating the safety of the retrievability of the valve.

[0079] In some alternative embodiments, the axis of the stepped hole has an angle ɑ with the mounting edge, and the value range of the angle ɑ is greater than 40° and less than 140°. In these embodiments, the stepped hole can be directly opened perpendicular to the mounting edge or can be opened obliquely relative to the vertical direction. The value range of the angle ɑ formed by the stepped hole and the mounting edge is between 40° and 140°. In this way, it can be opened according to the actual human situation. For example, during the experiment, a stepped hole that is inclined relative to the vertical direction is formed, so as to accurately simulate the state of the heart valve during retrieval in the human body.

[0080] In some alternative embodiments, the distal end of the coupling structure is connected to the second clamping end of the force measuring device, wherein the second clamping end is arranged opposite to the first clamping end. In these embodiments, the distal end of the coupling structure is connected to the second clamping end, and the clamping edge is connected to the first clamping end. When retrieving the implant, since the distal end of the loading sheath is limited at the second hole of the stepped hole, by pulling the second clamping end of the force measuring device, the implant at the distal end of the coupling structure is driven into the loading sheath, realizing the test of the force magnitude when the implant is received into the delivery device without using auxiliary tools in the expanded state.

[0081] In some alternative embodiments, a stage is provided on the clamping edge and is received in the test cavity. A connecting portion protruding away from the test cavity is further provided on the clamping edge, and the connecting portion is connected to the first clamping end of the force measuring device; preferably, the stage is used to carry the body temperature simulation container; preferably, the stage is welded or assembled with nuts on the clamping edge; in these embodiments, the stage is used to place the body temperature simulation container that provides a simulated human body temperature for the implant, making the test environment closer to the in-vivo environment and improving the accuracy of the test. The welding or nut assembly method can improve the load-bearing stability of the stage.

[0082] Furthermore, the connecting portion is a plate, and the first clamping end has a chuck, and the plate can be clamped on the chuck; even further, the connecting portion is embedded in the first clamping end, and a through fixing hole is provided at the free end of the connecting portion, and a connecting pin can be inserted into the fixing hole to be fixed on the first clamping end. In these embodiments, the form of the connecting portion can be improved differently according to the fixing method of the first clamping end. When the first clamping end is a chuck, the connecting portion can be a plate for easy clamping by the chuck; considering that the first clamping end of the force measuring mechanism on the market has a connection method through a positioning pin, therefore, the connecting portion can be set as a columnar shape adapted to the first clamping end, a radial hole is opened at the free end of the connecting portion, and the connecting edge is connected to the first clamping end of the force measuring device with a connecting pin, which is more stable and reliable.

[0083] In some alternative embodiments, the supporting portion is a pair of columns provided for connecting the mounting edge and the clamping edge, and the columns, the mounting edge and the clamping edge enclose to form the test cavity. In these embodiments, the test cavity is composed of the mounting edge, the clamping edge and two columns for connecting the mounting edge and the clamping edge, that is, the fixture forms a frame structure composed of multiple edges instead of being surrounded by a surface. Then, during the test, the visualization degree is high, which is convenient for observing whether the implant and the delivery device are damaged, and further optimizing the implant or the delivery device in combination with the force-bearing situation to improve the safety of the recyclable performance of the implant.

[0084] Preferably, the connection manner between the support part, the mounting edge and the clamping edge is one or more of threaded connection, snap - fit connection, welding or adhesive connection. Further, the support part is fixedly connected to the mounting edge by a first bolt. The other end of the support part has a groove axially formed thereon, and mounting holes corresponding to each other are formed on both side walls of the groove. After the connection edge is snap - fitted into the groove, it is fixedly connected to the support part by a second bolt. The mounting directions of the first bolt and the second bolt on the support part are perpendicular to each other. Furthermore, the mounting edge can be fixed at different height positions of the support part; still further, a plurality of threaded holes arranged axially are formed on the side surface of one end of the support part, and the mounting edge can be fixed at different height positions of the column by being installed in the threaded holes at different positions. In these embodiments, the mounting edge is adjustably mounted on the support part, which is convenient for testing implants of different sizes, such as short valves, long valves, etc.

[0085] The present application also discloses a device for testing the recovered force of an implant, and the device includes:

[0086] A force measuring device, the force measuring device having a force applying unit providing a first clamping end and a second clamping end, and the first clamping end and the second clamping end can move away from each other.

[0087] The fixture is used to place the implant to be tested connected to the proximal end of the conveying device into the test cavity. The clamping edge of the fixture is connected to the first clamping end, and the distal end of the conveying device is connected to the second clamping end;

[0088] The force measuring device tests the condition of the implant to be recovered into the conveying device through the back - ward movement.

[0089] In these embodiments, the device for testing the recovered force of an implant can be used to provide the magnitude of the force for judging the recovery of a heart valve into the loading sheath of the conveying device without auxiliary tools in the expanded state. By installing the above - mentioned fixture on a force measuring device (such as a tensile testing machine) for cooperation, it can simulate the magnitude of the force when an implant (such as a heart valve) is recovered into the sheath at body temperature. Since the test cavity is in a through - state, whether there is damage to the implant (such as a heart valve) and the loading sheath of the conveying device can be observed during the experiment, so as to judge the safety of the recoverable performance of the heart valve.

[0090] In some alternative embodiments, the force measuring device further includes a test unit and a calculation and output unit connected by signal. The test unit is installed on the first clamping end / second clamping end, and is used to detect the magnitude of the force and send the detected data to the calculation and output unit, and the calculation and output unit is used to display the detected data;

[0091] Preferably, the force measuring device is a tensile testing machine; preferably, the testing unit is a sensor; further, the sensor is a force sensitive element.

[0092] In some alternative embodiments, the first clamping end further includes a connecting cylinder, and a radially extending through hole is provided at the free end of the connecting cylinder; the connecting portion is a columnar object adapted to the connecting cylinder, and a through fixing hole is provided at the free end of the connecting portion. When the connecting portion is installed in the connecting cylinder, the through hole corresponds to the fixing hole, and the connecting portion is fixed to the first clamping end by a connecting pin passing through the through hole and the fixing hole.

[0093] A method for in vitro testing the force received by an implant during retrieval using the device includes the following steps:

[0094] Insert the proximal end of the coupling structure into the loading sheath and connect it to the implant to be tested to form a test portion;

[0095] Pass the distal end of the coupling structure in the test portion sequentially through the first hole and the second hole of the fixture and then connect it to the second clamping end;

[0096] Install the connecting portion of the clamping edge in the fixture on the first clamping end;

[0097] Start the force measuring device to move the second clamping end away from the first clamping end;

[0098] Observe the morphological changes of the proximal end of the loading sheath and the implant to be tested for qualitative evaluation.

[0099] Preferably, the first clamping end / the second clamping end is further provided with a testing unit, and the testing unit is signal-connected to a calculation and output unit. During observation, quantitative evaluation can also be performed according to the output data of the calculation and output unit.

[0100] To more clearly understand the fixture and the device for testing the force received by the implant during retrieval provided by the embodiments of the present disclosure, the specific embodiments of the present invention will be described below with reference to the accompanying drawings. In this process, the thickness of the lines or the size of the structural elements shown in the drawings may be exaggerated for the sake of clarity and convenience of illustration.

[0101] Embodiment 1

[0102] In the present application, the proximal end refers to the end close to the implant 600, i.e., the heart valve, and the distal end refers to the end far from the implant 600, i.e., the heart valve. Please refer to Figure 1 and Figures 8-9, the present application provides a fixture for providing a test platform for the implant 600. One end of the fixture is connected to a test end of the force measuring device 700, which plays a role of fixed connection and support. The other end can be placed into the delivery device 500 for retrieving the implant 600 and generates a certain obstructive effect on the delivery device 500. The other test end of the force measuring device 700 provides a retrieval force for the implant 600 through the delivery device 500, so that the implant 600 can enter the delivery device 500 without the aid of other auxiliary tools in the expanded state.

[0103] Please refer to Figures 7-9 , in this embodiment, the implant 600 takes a heart valve as an example; the delivery device 500 for retrieving the heart valve includes a coupling structure 510 and a loading sheath 520 sleeved on the proximal end of the coupling structure 510. The proximal end of the coupling structure 510 is connected to the implant 600, and the loading sheath 520 is used to retrieve and accommodate the implant 600. As is well known, the working principle of the force measuring device 700 is that one end is fixedly connected to the object to be tested, and the other end provides a pulling force for the object to be tested. In this embodiment, the force measuring device 700 is a tensile machine, which has opposite first clamping ends 711 and second clamping ends 712. The first clamping end 711 is used to fix the object to be tested, and the second clamping end 712 can be freely stretched. During the test, the proximal end of the coupling structure 510 can be connected to the implant 600, and the distal end of the coupling structure 510 can be connected to the second clamping end 712 of the force measuring device 700.

[0104] Among them, please continue to refer to Figure 1 and Figure 8 , the fixture includes a mounting edge 200, a clamping edge 300, and a support portion 400 for connecting the mounting edge 200 and the clamping edge 300. In this embodiment, the support portion is composed of two oppositely arranged columns, and the two columns are respectively arranged at both ends of the mounting edge 200 / clamping edge 300. The mounting edge 200, the clamping edge 300, and the two columns enclose a test chamber 100, and the test chamber 100 is provided with a body temperature simulation container 311 for accommodating the heart valve.

[0105] Please refer to Figures 4-5, the connection mode of the column with the mounting edge 200 and the clamping edge 300 is one or several of threaded connection, snap-fit connection, welding or adhesive connection. In this embodiment, the column is fixedly connected to the mounting edge 200 by a first bolt. The mounting edge 200 can be fixed at different height positions of the column. Specifically, a plurality of axially arranged threaded holes 410 are formed on the side surface of one end of the column, and the mounting edge 200 can be fixed at different height positions of the column by being installed in the threaded holes 410 at different positions. The other end of the column has a groove 420 axially formed. Mounting holes corresponding to each other are formed on the two side walls of the groove 420. After the connecting edge is snap-fitted into the groove 420, it is fixedly connected to the column by a second bolt. The installation directions of the first bolt and the second bolt on the column are perpendicular to each other.

[0106] Please refer to Figures 2-3 , the mounting edge 200 is arranged on one side of the test chamber 100 and can be specifically a plate-shaped object. A through stepped hole 210 is formed on the mounting edge 200. The stepped hole 210 includes a first hole 211 and a second hole 212 that sequentially extend towards the test chamber 100. The diameter of the first hole 211 is adapted to the diameter of the loading sheath 520, and the diameter of the second hole 212 is smaller than the diameter of the loading sheath 520. Based on the fact that the diameter of the first hole 211 close to the test chamber 100 is adapted to the diameter of the loading sheath 520, the first hole 211 is used to insert the loading sheath 520 and provide a certain radial supporting force for the loading sheath 520 to ensure vertical force. Since the diameter of the second hole 212 is smaller than the diameter of the loading sheath 520, during the recovery process, by pulling the coupling structure 510 with the second clamping end 712 of the stretching machine, the heart valve will push the loading sheath 520. Due to the existence of the second hole 212, it will generate a certain obstructive effect on the distal end of the loading sheath 520, so that the heart valve can be retracted into the loading sheath 520 without the action of other auxiliary devices. In this embodiment, the depth of the first hole 211 is smaller than the length of the loading sheath 520, that is, the end of the loading sheath 520 protrudes from the first hole 211. During the recovery process of the heart valve, the experimenter can directly observe whether the loading sheath 520 and the heart valve are damaged, so as to evaluate the safety of the recoverable performance of the heart valve. In addition, the stepped hole 210 can be directly formed perpendicular to the mounting edge 200 or can be formed obliquely relative to the vertical direction. The value range of the included angle ɑ formed by the stepped hole 210 and the mounting edge 200 is between 40° and 140°. In this way, it can be formed according to the actual human situation. For example, during the experiment, a stepped hole 210 that is inclined relative to the vertical direction is formed, so as to accurately simulate the state of the heart valve during recovery in the human body.

[0107] Please refer to Figure 6, the clamping edge 300 is located on the opposite side of the mounting edge 200 and can also be in the shape of a plate. The clamping edge 300 can be used to connect to the first clamping end 711 of the stretching machine. Specifically, a loading platform 310 protruding into the test chamber 100 is provided on the clamping edge 300. The loading platform 310 is welded or assembled with nuts on the clamping edge 300 and is used to support the body temperature simulation container 311. A solution such as hot water close to body temperature can be placed in the body temperature simulation container 311. A connecting portion 320 protruding away from the test chamber 100 is also provided on the clamping edge 300. The connecting portion 320 is connected to the first clamping end 711 of the force measuring device 700. The form of the connecting portion 320 can be improved differently according to the fixing method of the first clamping end 711. When the first clamping end 711 is a chuck, the connecting portion 320 can be a plate for easy clamping by the chuck. Considering that the first clamping end 711 of the stretching machine on the market has a connection method through a positioning pin, that is, the connecting portion 320 of the first clamping end 711 is a connecting cylinder, and a radially extending through hole is provided at the free end of the connecting cylinder. Therefore, the connecting portion 320 of the clamping edge 300 can be set as a column adapted to the connecting cylinder, and a radial hole is opened at the free end of the connecting portion 320, and the connecting edge is connected to the first clamping end 711 of the force measuring device 700 with a connecting pin, which is more stable and reliable.

[0108] The fixture provided in this embodiment is used as a test platform for subsequent measurement of the force between the retrievable transcatheter heart valve and the loading sheath 520 during retrieval. It is convenient to operate and can simulate the environment when the implant 600 is retrieved in the human body, which can improve the accuracy of subsequent tests.

[0109] Embodiment 2

[0110] Please refer to Figure 9 , this embodiment provides a device for testing the retrieval force of the implant 600. The device includes a force measuring device 700 and a fixture. The force measuring device 700 has a force applying unit 710, a testing unit 720, and a calculation and output unit 730 that are signal-connected. The force applying unit 710 includes a first clamping end 711 and a second clamping end 712; the testing unit 720 is installed on the first clamping end 711 / the second clamping end 712 and is used to detect the magnitude of the force and send the detection data to the calculation and output unit 730. The calculation and output unit 730 is used to display the detection data; the fixture is used to place the implant 600 to be tested in the body temperature simulation container 311 through the conveying device 500. The clamping edge 300 of the fixture is connected to the first clamping end 711, and the distal end of the conveying device 500 is connected to the second clamping end 712. The implant 600 to be tested can be retrieved into the conveying device 500 as the force applying unit 710 operates.

[0111] Embodiment 3

[0112] This embodiment provides a method for in vitro testing of the recovery force of an implant using the device described in Embodiment 2, including the following steps:

[0113] Set up the test section. Please refer to Figure 7 , insert the proximal end of the coupling structure 510 into the loading sheath 520 and connect it to the implant to be tested, i.e., the heart valve, to form the test section; that is, pass the distal end of the coupling structure 510 through the loading sheath 520 and then through the stepped hole 210, and connect the proximal end of the coupling structure 510 to the heart valve.

[0114] Assemble the fixture. Please refer to Figure 8 , fixedly connect the mounting edge 200 to the upper part of the column through the threaded hole 410 on the column using screws; the groove 420 at the lower part of the column is clamped to the upper end of the clamping edge 300, and a nut is passed through the lower end of the column and fixed to the clamping edge 300; a loading platform 310 is fixed on the upper plane of the clamping edge 300, and a body temperature simulation container 311 is placed on the loading platform 310. Subsequently, hot water at 37 - 40 °C can be added to the body temperature simulation container 311, and the heart valve is immersed in the hot water and is in an expanded and enlarged state.

[0115] Install the fixture on the test device. Figure 9 As a schematic diagram of the combined use of the fixture equipped with the test device and the tensile machine, clamp the connecting part 320 of the clamping edge 300 to the chuck of the first clamping end 711 in the tensile machine; the distal end of the coupling structure 510 passes through the stepped hole 210 on the mounting edge 200 and is clamped to the chuck of the second clamping end 712 in the tensile machine. Slightly adjust the chuck of the second clamping end 712 in the tensile machine to move it upward, so that the loading sheath 520 and the second hole 212 of the stepped hole 210 generate a squeezing force; put hot water at 37 - 40 °C into the body temperature simulation container 311 so that the heart valve immersed in the hot water can maintain a fully expanded state.

[0116] Test analysis step: Start the tensile machine. The chuck of the second clamping end 712 in the tensile machine slowly rises, driving the distal end of the coupling structure 510 to move upward together. The heart valve connected to the proximal end of the coupling structure 510 is compressed into the loading sheath 520 under the action of the tensile force. Due to the hindrance of the stepped part to the distal end of the loading sheath 520, the heart valve will enter from the proximal end of the loading sheath 520. During this process, a large squeezing deformation will occur between the heart valve and the proximal end of the loading sheath 520. Observe and record the magnitude of the force during the recovery process, and whether there are phenomena such as unhooking and damage or failure of the loading sheath 520, and conduct a qualitative assessment of the retrievability of the heart valve.

[0117] Of course, a test unit 720 and a calculation and output unit 730 with signal connection can also be arranged on the force measuring device. The test unit 720 is installed at the first clamping end 711 / the second clamping end 712 and is used to detect the magnitude of the force and send the detected data to the calculation and output unit 730. The calculation and output unit 730 is used to display the detected data, and the experimenter can make a quantitative evaluation according to the output data of the calculation and output unit.

[0118] It can be understood that the same or similar parts in the above embodiments can be referred to each other, and the content not described in detail in some embodiments can be found in the same or similar content of other embodiments. It should be noted that the terms in the description of the present application are defined in consideration of their functions in the present invention and may vary according to the intentions or conventions of the users. Therefore, the definitions of such terms should be based on the overall content of this specification.

[0119] For example, the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation on the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0120] In the description of this specification, unless otherwise clearly specified and defined, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

[0121] The description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0122] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A fixture, characterized in that, It includes a support portion, and mounting edges and clamping edges provided at both ends of the support portion. The mounting edges, the support portion, and the clamping edges enclose a test cavity for accommodating the implant to be tested. A through stepped hole is provided on the mounting edge. The stepped hole allows the proximal end of the delivery device to extend into and be limited in the test cavity. The proximal end is used to connect the implant to be tested. The clamping edge can be connected to the first clamping end of the force measuring device. The delivery device includes a coupling structure and a loading sheath tube sleeved on the proximal end of the coupling structure. The proximal end of the coupling structure is connected to the implant. The stepped hole includes a first hole and a second hole. The first hole is located at the distal end of the stepped hole, and the diameter of the first hole is adapted to the diameter of the loading sheath tube. The diameter of the second hole is smaller than the diameter of the loading sheath tube and is adapted to the diameter of the coupling structure. The depth of the first hole is less than the length of the loading sheath tube.

2. The fixture according to claim 1, wherein, The axis of the stepped hole has an angle ɑ with the mounting edge, and the value range of the angle ɑ is greater than 40° and less than 140°.

3. The fixture according to claim 1, wherein A loading platform is provided on the clamping edge and is accommodated in the test cavity. A connecting portion protruding away from the test cavity is further provided on the clamping edge, and the connecting portion is connected to the first clamping end of the force measuring device.

4. The fixture according to claim 3, wherein the loading platform is used to carry the body temperature simulation container; the connecting portion is a plate, the first clamping end has a chuck, and the plate can be clamped on the chuck; the connecting portion is embedded in the first clamping end, and a through fixing hole is provided at the free end of the connecting portion. A connecting pin can be inserted into the fixing hole to be fixed on the first clamping end.

5. The jig according to claim 1, wherein The connection manner of the support portion with the mounting edge and the clamping edge is one or several of threaded connection, snap-fit connection, welding, or adhesive connection; The support portion is fixedly connected to the mounting edge by a first bolt.

6. The fixture according to claim 5, wherein the mounting edge can be fixed at different height positions of the support portion; Further, a plurality of axially arranged threaded holes are provided on the side surface of one end of the support portion. The mounting edge can be fixed at different height positions of the support portion by being installed in the threaded holes at different positions.

7. The fixture according to claim 5, wherein The other end of the support portion has an axially opened groove, and mounting holes corresponding to each other are provided on both side walls of the groove. After the connecting edge is snap-fitted into the groove, it is fixedly connected to the support portion by a second bolt.

8. A device for testing the force on the retrieval of an implant, characterized in that, The device includes: A force measuring device. The force measuring device has a force applying unit providing a first clamping end and a second clamping end. A backward movement can be performed between the first clamping end and the second clamping end. The fixture according to any one of claims 1-7, which is used to place the implant to be tested connected to the proximal end of the delivery device in the test cavity. The clamping edge of the fixture is connected to the first clamping end, and the distal end of the delivery device is connected to the second clamping end; The force measuring device tests the condition of recovering the implant to be tested into the delivery device through the backward movement.

9. The device according to claim 8, characterized in that, The force measuring device further includes a test unit and a calculation and output unit that are signal-connected. The test unit is installed at the first clamping end / the second clamping end, and is used to detect the magnitude of the force and send the detected data to the calculation and output unit. The calculation and output unit is used to display the detected data.

10. The device according to claim 9, wherein the force measuring device is a tensile testing machine; the test unit is a sensor; the sensor is a force-sensitive element.

11. The device according to claim 8, wherein The first clamping end further includes a connecting cylinder, and a radially extending through hole is provided at the free end of the connecting cylinder; the connecting portion is a columnar object adapted to the connecting cylinder, and a through fixing hole is provided at the free end of the connecting portion. When the connecting portion is installed in the connecting cylinder, the through hole corresponds to the fixing hole, and the connecting portion is fixed to the first clamping end by a connecting pin passing through the through hole and the fixing hole.

12. A method for in vitro testing the force received by an implant during retrieval using the device according to any one of claims 8-11, comprising the following steps: Insert the proximal end of the coupling structure into the loading sheath and connect it to the implant to be tested to form a test portion; Pass the distal end of the coupling structure in the test portion sequentially through the first hole and the second hole of the fixture and then connect it to the second holding end; Install the connecting portion of the clamping edge in the fixture on the first clamping end; Start the force measuring device to move the second clamping end away from the first clamping end; Observe the morphological changes of the proximal end of the loading sheath and the implant to be tested for qualitative evaluation.

13. The method according to claim 12, wherein The first clamping end / the second clamping end is further provided with a test unit, and the test unit is signal-connected to a calculation and output unit. During observation, quantitative evaluation can also be performed according to the output data of the calculation and output unit.

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