A device and method for measuring phase change recovery temperature of nickel-titanium alloy esophageal stent

Abstract

The present invention discloses a device and method for measuring the phase change recovery temperature of a nickel-titanium alloy esophageal stent, and belongs to the technical field of material phase change recovery temperature measurement. The device includes a force sensor, a test auxiliary, a bearing, a temperature recorder, a container, a heating element, and a data processing system; the bearing is connected to the inner bottom wall of the container through a support column, the test auxiliary is arranged above the bearing, the force sensor is connected to the upper part of the test auxiliary through a first connecting member, the nickel-titanium alloy esophageal stent to be tested is used to be carried on the upper surface of the bearing, and the spacing distance between the test auxiliary and the bearing is less than the diameter of the nickel-titanium alloy esophageal stent to be tested before the phase change; the container is used to hold a heat-conducting liquid; the container is placed on the surface of the heating element; the temperature recorder is used to extend into the heat-conducting liquid; the data processing system is connected to the force sensor signal. The device has a simple structure and is easy to operate, and the measurement method is simple to operate, efficient, and accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of material phase change recovery temperature measurement, and in particular to a device and method for measuring the phase change recovery temperature of a nickel-titanium alloy esophageal stent. Background Art

[0002] Nickel-titanium alloy is a common shape memory material. It has many characteristics such as shape memory, superelasticity and fatigue resistance. In order to ensure the quality control of nickel-titanium alloy materials or their parts, it is necessary to measure the austenite recovery end temperature of nickel-titanium alloy. The current system for measuring the austenite recovery end temperature of shape memory alloy parts is the Af point tester (BFR).

[0003] However, the BFR measuring instrument requires the purchase of many expensive parts, the manufacturing technology is particularly complex, and the measurement efficiency is low.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] One of the purposes of the present invention is to provide a device for measuring the phase change recovery temperature of a nickel-titanium alloy esophageal stent, which has a simple structure, is easy to manufacture and has a low cost.

[0006] The second object of the present invention is to provide a method for measuring the phase change recovery temperature of a nickel-titanium alloy esophageal stent, which has the advantages of simple operation, high efficiency and accurate results.

[0007] This application can be implemented as follows:

[0008] In a first aspect, the present application provides a device for measuring the phase change recovery temperature of a nickel-titanium alloy esophageal stent, including a force sensor, a test auxiliary, a bearing, a temperature recorder, a container, a heating element, and a data processing system;

[0009] In the use state, the bearing member is connected to the inner bottom wall of the container through the support column, the test auxiliary member is arranged above the bearing member at intervals, the force sensor is connected to the upper part of the test auxiliary member through the first connecting member, the nickel-titanium alloy esophageal stent to be tested is used to be carried on the upper surface of the bearing member, and the interval distance between the test auxiliary member and the bearing member is less than the diameter of the nickel-titanium alloy esophageal stent to be tested before the phase change;

[0010] The container contains a heat-conducting liquid; the container is in contact with the surface of the heating element;

[0011] The temperature measuring part of the temperature recorder extends into the area of ​​the container for containing the heat-conducting liquid to record the temperature of the heat-conducting liquid;

[0012] The data processing system is connected with the force sensor signal.

[0013] In an optional embodiment, the measuring device further includes a nickel-titanium alloy esophageal stent to be tested, and the nickel-titanium alloy esophageal stent to be tested is supported on the upper surface of the supporting member.

[0014] In an optional embodiment, two ends of the first connecting member are respectively threadedly connected to the test auxiliary component and the force sensor.

[0015] In an optional embodiment, the number of temperature recorders is not less than 2.

[0016] In an alternative embodiment, a plurality of temperature recorders are spaced apart along the circumference of the container.

[0017] In an optional embodiment, when the number of the temperature recorders is an even number, the even number of temperature recorders are symmetrically arranged with the nickel-titanium alloy esophageal stent to be tested as a symmetry axis.

[0018] In an optional embodiment, the distance between the temperature recorder and the nickel-titanium alloy esophageal stent to be tested is 1-2 cm.

[0019] In an optional embodiment, the heat-conducting liquid is anhydrous ethanol.

[0020] In an optional embodiment, the initial temperature of the heat transfer liquid is not higher than -50°C.

[0021] In an optional embodiment, the measuring device further comprises an agitator, and the agitator is arranged in the area between the inner bottom wall of the container, the lower surface of the carrier and the support column.

[0022] In an optional embodiment, the data processing system is also connected to the temperature recorder signal.

[0023] In an optional embodiment, the measuring device further comprises a second connecting member, one end of which is connected to the force sensor, and the other end of which is connected to the outside world so that the force sensor is in a vertical state during use.

[0024] In the second aspect, the present application provides a method for measuring the phase change recovery temperature of a nickel-titanium alloy esophageal stent, comprising the following steps: using the measuring device of any of the aforementioned embodiments, turning on the heating element to heat the heat-conducting liquid in the container, so that the volume of the nickel-titanium alloy esophageal stent to be tested gradually expands as the temperature of the heat-conducting liquid increases; when the diameter of the nickel-titanium alloy esophageal stent to be tested after expansion is greater than the distance between the test auxiliary component and the supporting component, the volume of the nickel-titanium alloy esophageal stent to be tested squeezes the test auxiliary component upward during continued expansion and obtains the corresponding force value through a force sensor; when the value of the force sensor does not change with the increase in the temperature of the heat-conducting liquid, the temperature of the heat-conducting liquid at this time is used as the phase change recovery temperature of the nickel-titanium alloy esophageal stent.

[0025] In an optional embodiment, when the value of the force sensor does not change with the increase of the temperature of the heat-conducting liquid, the temperature of the heat-conducting liquid is increased by at least 10°C. If the value of the force sensor does not change, the temperature of the heat-conducting liquid at this time is used as the phase change recovery temperature of the nickel-titanium alloy esophageal stent.

[0026] The beneficial effects of this application include:

[0027] The measuring device for the phase change recovery temperature of the nickel-titanium alloy esophageal stent provided in the present application only needs to be assembled and connected by a low-cost force sensor, a nickel-titanium alloy esophageal stent to be tested, a test auxiliary, a bearing, a temperature recorder, a container, a heating element, etc., and has a simple structure, is easy to manufacture, and has a low cost. The measurement device is used to measure the phase change recovery temperature of the corresponding nickel-titanium alloy esophageal stent, which is easy to operate, efficient, and accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 A schematic diagram of the structure of a device for measuring the phase change recovery temperature of a nickel-titanium alloy esophageal stent provided in the present application.

[0030] Icons: 10-force sensor; 11-first connecting piece; 12-second connecting piece; 13-crossbeam; 14-wall; 20-nitinol esophageal stent to be tested; 30-test accessories; 40-bearing part; 41-support column; 50-temperature recorder; 60-container; 61-heat-conducting liquid; 70-heating element; 80-data processing system; 90-stirrer. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0032] The following is a detailed description of the device and method for measuring the phase change recovery temperature of the nickel-titanium alloy esophageal stent provided in the present application.

[0033] like Figure 1As shown, the present application proposes a device for measuring the phase change recovery temperature of a nickel-titanium alloy esophageal stent, including a force sensor 10, a nickel-titanium alloy esophageal stent 20 to be tested, a test auxiliary component 30, a carrier 40, a temperature recorder 50, a container 60, a heating component 70 and a data processing system 80.

[0034] In the use state, the carrier 40 is connected to the inner bottom wall of the container 60 through the support column 41, the test auxiliary 30 is arranged above the carrier 40, the force sensor 10 is connected to the upper part of the test auxiliary 30 through the first connecting member 11, and the nickel-titanium alloy esophageal stent 20 to be tested is used to be carried (placed) on the upper surface of the carrier 40, and the spacing distance between the test auxiliary 30 and the carrier 40 is less than the diameter of the nickel-titanium alloy esophageal stent 20 to be tested before the phase change;

[0035] The container 60 contains a heat-conducting liquid 61; the container 60 is in contact with the surface of the heating element 70 (eg, directly placed on the surface of the heating element 70);

[0036] The temperature measuring part of the temperature recorder 50 extends into the area of ​​the container 60 for containing the heat-conducting liquid 61 to record the temperature of the heat-conducting liquid 61;

[0037] The data processing system 80 is signal-connected to the force sensor 10 .

[0038] For reference, the carrier 40 may be in the shape of a plate or a block. The carrier 40 is located in the container 60 and above the inner bottom wall of the container 60. Both ends of the support column 41 are connected to the carrier 40 and the inner bottom wall of the container 60, respectively.

[0039] Specifically, one end of the support column 41 can be threadedly connected, clamped or bonded to the carrier 40 by way of example but not limitation. When the support column 41 is threadedly connected to the carrier 40, the carrier 40 is correspondingly provided with an internal threaded hole, and the outer wall of the support column 41 has an external thread that matches the internal threaded hole. When the support column 41 is clamped with the carrier 40, the outer wall of the support column 41 is provided with a clamping block, and the carrier 40 is provided with a clamping groove that matches the clamping block. One end of the support column 41 used for connecting to the inner bottom wall of the container 60 is preferably bonded to the inner bottom wall of the container 60. When the support column 41 is bonded to the inner bottom wall of the carrier 40 or the container 60, the adhesive used is an adhesive that is insoluble in the heat-conducting solution.

[0040] Preferably, the number of support columns 41 can be 4, which are respectively connected to the four corners of the carrier 40, which improves the support and stabilization effect of the carrier 40. The height of the support column 41 is preferably 5-10 cm, which is convenient for operation on the one hand, and can prevent the stirrer 90 from affecting the carrier 40 during stirring on the other hand.

[0041] For reference, the carrier 40 can be made of POM material. On the one hand, the carrier 40 made of this material has a relatively smooth surface and will not cause damage to the surface of the nickel-titanium alloy esophageal stent 20 to be tested; on the other hand, this material will not generate too much buoyancy in the heat-conducting solution, reducing the possibility of the buoyancy generated by the carrier 40 causing adverse effects on the test results.

[0042] The test auxiliary component 30 can be in the shape of a plate or a block, and can be understood as a baffle-like object. Similarly, the test auxiliary component 30 can also be made of POM material.

[0043] In the present application, the spacing distance between the test auxiliary component 30 and the supporting component 40 is smaller than the diameter of the nickel-titanium alloy esophageal stent 20 to be tested before the phase change, so as to ensure that the nickel-titanium alloy esophageal stent 20 to be tested can contact the test auxiliary component 30 during the expansion process and generate an upward force on the test auxiliary component 30, so that the force sensor 10 can sense the corresponding force.

[0044] In some optional embodiments, the cross-sectional dimensions of the carrier 40 are not less than the length and diameter of the nickel-titanium alloy esophageal stent 20 to be tested. That is, the nickel-titanium alloy esophageal stent 20 to be tested after placement is completely located on the upper surface of the carrier 40, without any part extending out of the carrier 40. Preferably, the cross-sectional dimensions of the test auxiliary 30 are also not less than the length and diameter of the nickel-titanium alloy esophageal stent 20 to be tested, that is, the test auxiliary 30 can cover the projection of the nickel-titanium alloy esophageal stent 20 to be tested on the plane where its cross section is located.

[0045] In some specific embodiments, the nickel-titanium alloy esophageal stent 20 to be tested is tubular, with an outer diameter of 22 mm and a length of 140 mm. Accordingly, the dimensions of the support member 40 and the test auxiliary member 30 are both: 200 mm in length, 50 mm in width, and 5 mm in thickness. In other embodiments, the dimensions of the support member 40 and the test auxiliary member 30 can be adjusted accordingly according to the specific dimensions of the nickel-titanium alloy esophageal stent 20 to be tested.

[0046] Preferably, the position of the nickel-titanium alloy esophageal stent 20 to be tested on the supporting member 40 corresponds to the central area of ​​the water tank, and the measurement result of this position is more accurate.

[0047] The first connecting member 11 can be a connecting rod, and the connection between it and the test auxiliary component 30 and the force sensor 10 can be exemplarily but not limitatively a threaded connection, a clamping connection or an adhesive connection. When the first connecting member 11 and the test auxiliary component 30 are threadedly connected, the test auxiliary component 30 is correspondingly provided with an internal threaded hole, and the outer wall of the first connecting member 11 has an external thread that matches the above-mentioned internal threaded hole. When the first connecting member 11 is clamped with the test auxiliary component 30, the outer wall of the first connecting member 11 is provided with a clamping block, and the test auxiliary component 30 is provided with a clamping groove that matches the clamping block. The same is true for the end of the first connecting member 11 used for connection with the force sensor 10.

[0048] For reference, the force sensor 10 is made of metal, and the accuracy of the force sensor 10 is preferably not less than ±0.05N.

[0049] In the present application, the container 60 can be a water tank or other forms of container 60, and its material can be acrylic material. The interior is used to hold the heat-conducting liquid 61, preferably anhydrous ethanol with a temperature not higher than -50°C, and can also be other liquid substances with the above temperature.

[0050] It should be noted that the initial temperature of the heat-conducting liquid 61 in the present application needs to be set at no higher than -50°C. The reason is that the formation of martensite needs to be ensured before the phase transition temperature is measured. The formation of martensite requires a certain cooling rate or deep supercooling. Compared with the cooling rate, -50°C is a relatively easy test condition. During the measurement process, the heat-conducting liquid 61 needs to cover the nickel-titanium alloy esophageal stent 20 to be tested, that is, the nickel-titanium alloy esophageal stent 20 to be tested needs to be immersed in the heat-conducting liquid 61.

[0051] The heating element 70 may be a temperature heating platform, which may be made of metal and equipped with a software control system. During measurement, the container 60 is directly placed on the surface of the heating element 70 , and the temperature heating platform can directly heat the container 60 , thereby conducting heat to the heat-conducting liquid 61 in the container 60 .

[0052] In an optional embodiment, in the present application, the number of the temperature recorders 50 is not less than 2, such as 2, 3, 4 or more. Preferably, all the temperature recorders 50 are arranged at intervals along the circumference of the container 60, and more preferably at equal intervals.

[0053] When the number of the temperature recorders 50 is an even number, the even number of temperature recorders 50 are preferably symmetrically arranged with the nickel-titanium alloy esophageal stent 20 to be tested as the symmetry axis. For example, when the number of the temperature recorders 50 is 2, the two temperature recorders 50 can be symmetrically arranged on the left and right sides or the front and back sides of the nickel-titanium alloy esophageal stent 20 to be tested; when the number of the temperature recorders 50 is 4, the four temperature recorders 50 can be symmetrically arranged on the left and right sides or the front and back sides of the nickel-titanium alloy esophageal stent 20 to be tested.

[0054] The final measurement result is based on the average value of the values ​​measured by all temperature recorders 50. By arranging multiple temperature recorders 50 and arranging them in symmetrical positions, the accuracy of the measurement result can be improved.

[0055] Preferably, the distance between the portion of the temperature recorder 50 extending into the heat-conducting liquid 61 and the nickel-titanium alloy esophageal stent 20 to be tested is 1-2 cm. Since the actual temperature of the heat-conducting liquid 61 at different positions in the container 60 may be different, the temperature recorder 50 is set at a position 20-2 cm away from the nickel-titanium alloy esophageal stent to be tested, so that the result can be closer to the actual temperature of the nickel-titanium alloy esophageal stent 20 to be tested. If the temperature recorder 50 is less than 1 cm away from the nickel-titanium alloy esophageal stent 20 to be tested, the value thereof is easily fluctuated due to the stirring action of the stirrer 90.

[0056] The temperature recorder 50 may be, for example, a Precision RC-4 temperature recorder 50 .

[0057] Furthermore, the measuring device further comprises an agitator 90 , which is disposed in a region between the inner bottom wall of the container 60 , the lower surface of the carrier 40 and the support column 41 .

[0058] By providing the stirrer 90 , the heat-conducting liquid 61 in the container 60 can be stirred, thereby improving the uniformity of the temperature of each position of the heat-conducting liquid 61 .

[0059] For reference, the data processing system 80 of the present application may be a software program.

[0060] In a preferred embodiment, the data processing system 80 is also connected to the temperature recorder 50 by signal.

[0061] Furthermore, the measuring device further comprises a second connecting member 12, one end of the second connecting member 12 is connected to the force sensor 10, and the other end is connected to the outside to keep the force sensor 10 in a vertical state during use.

[0062] For reference, the second connecting member 12 and the force sensor 10 can be threadedly connected, the second connecting member 12 and the first connecting member 11 are colinear, the other end of the second connecting member 12 can be connected to the beam 13, and the beam 13 can be fixed to the wall 14.

[0063] Correspondingly, the present application also provides a method for measuring the phase change recovery temperature of a nickel-titanium alloy esophageal stent, which mainly includes the following steps: using the above-mentioned measuring device, turning on the heating element 70 to heat the heat-conducting liquid 61 in the container 60, so that the volume of the nickel-titanium alloy esophageal stent 20 to be tested gradually expands as the temperature of the heat-conducting liquid 61 increases (that is, the nickel-titanium alloy esophageal stent 20 to be tested will continuously recover its shape before compression as the temperature continues to increase). When the diameter of the nickel-titanium alloy esophageal stent 20 to be tested after expansion is greater than the distance between the test auxiliary component 30 and the supporting component 40, the volume of the nickel-titanium alloy esophageal stent 20 to be tested squeezes the test auxiliary component 30 upward during the continued expansion process and obtains the corresponding force value through the force sensor 10. When the value of the force sensor 10 does not change with the increase in the temperature of the heat-conducting liquid 61, the temperature of the heat-conducting liquid 61 at this time is used as the phase change recovery temperature of the nickel-titanium alloy esophageal stent.

[0064] In a preferred embodiment, when the value of the force sensor 10 does not change with the increase in the temperature of the heat-conducting liquid 61, the temperature of the heat-conducting liquid 61 is increased by at least 10°C at the same heating rate. If the value of the force sensor 10 does not change, the temperature of the heat-conducting liquid 61 at this time is used as the phase change recovery temperature of the nickel-titanium alloy esophageal stent.

[0065] It can be understood that: if the value of the force sensor 10 does not change with the increase of the temperature of the heat-conducting liquid 61 for the first time, the temperature of the heat-conducting liquid 61 is increased by at least 10°C on this basis. If the value of the force sensor 10 changes again after the increase, the test is continued until the value of the force sensor 10 does not change with the increase of the temperature of the heat-conducting liquid 61 for the second time. On this basis, the temperature of the heat-conducting liquid 61 is increased by at least 10°C. If the value of the force sensor 10 does not change again after the increase, the measurement can be terminated.

[0066] Preferably, the result can be intuitively presented through a force-temperature curve diagram. For reference, the abscissa may correspond to the stress value, and the ordinate may correspond to the temperature.

[0067] During the above measurement process, the heating rate of the heat-conducting liquid 61 does not exceed 4°C / min, such as 0.5°C / min, 1°C / min, 1.5°C / min, 2°C / min, 2.5°C / min, 3°C / min, 3.5°C / min or 4°C / min. If the heating rate is too fast, it will easily cause uneven heating of the heat-conducting liquid 61.

[0068] Preferably, in order to improve the accuracy of the measurement results of the present application, before the test, the buoyancy of the support member 40 and the test auxiliary member 30 when the nickel-titanium alloy esophageal stent 20 to be tested is not placed is cleared to avoid errors in the results caused by the buoyancy of the support member 40 and the test auxiliary member 30 themselves.

[0069] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0070] Example 1

[0071] The present embodiment provides a device for measuring the phase change recovery temperature of a nickel-titanium alloy esophageal stent, which includes a force sensor 10, a nickel-titanium alloy esophageal stent 20 to be tested, a test auxiliary component 30, a carrier 40, a temperature recorder 50, a container 60, a heating component 70, an agitator 90 and a data processing system 80.

[0072] The carrier 40 is a carrier plate made of POM material. When in use, the carrier plate is located in the container 60 and above the inner bottom wall of the container 60. There are four support columns 41, each of which is 10 cm in height. The four support columns 41 are respectively threadedly connected to the four corners of the carrier plate. The four corners of the carrier plate are respectively provided with internal thread holes, and the outer wall of each support column 41 has an external thread that matches the internal thread hole one by one. The other end of each support column 41 is bonded to the inner bottom wall of the container 60.

[0073] The test auxiliary component 30 is a baffle made of POM material, which is spaced above the carrying plate.

[0074] The nickel-titanium alloy esophageal stent 20 to be tested is placed on the upper surface of the support plate at a position corresponding to the central area of ​​the water tank, and the spacing distance between the baffle and the support plate is smaller than the diameter of the nickel-titanium alloy esophageal stent 20 to be tested before phase change (95% of the nominal value of the measurement position).

[0075] After placement, the nickel-titanium alloy esophageal stent 20 to be tested is completely located on the upper surface of the support plate, without any part extending out of the support plate; the baffle is on the plane where its cross section is located, and can cover the projection of the nickel-titanium alloy esophageal stent 20 to be tested on the plane. Specifically, the nickel-titanium alloy esophageal stent 20 to be tested is tubular, with an outer diameter of 22 mm and a length of 140 mm. Correspondingly, the dimensions of the support plate and the baffle are: 200 mm long, 50 mm wide, and 5 mm thick.

[0076] The lower end of the force sensor 10 is connected to the upper surface of the baffle through the first connecting member 11 (first connecting rod), one end of the first connecting rod is threadedly connected to the baffle (the baffle is provided with an internal threaded hole, and the outer wall of the first connecting rod has an external thread that matches the internal threaded hole), and the other end is also threadedly connected to the force sensor 10. The force sensor 10 is made of metal, and the accuracy of the force sensor 10 is preferably not less than ±0.05N.

[0077] The upper end of the force sensor 10 is threadedly connected to a second connecting member 12 (second connecting rod), one end of the second connecting rod away from the force sensor 10 is connected to a beam 13 fixed to a wall 14, and the second connecting rod is collinear with the first connecting rod in the vertical direction.

[0078] The container 60 is an acrylic water tank, which contains a heat-conducting liquid 61 (anhydrous ethanol) with an initial temperature of -50°C, and the heat-conducting liquid 61 immerses the nickel-titanium alloy esophageal stent 20 to be tested. The heating element 70 is a temperature heating platform made of metal and equipped with a software control system, and the container 60 is placed on the surface of the heating element 70.

[0079] The temperature recorders 50 are two Precision RC-4 temperature recorders 50, which are symmetrically arranged on the left and right sides of the nickel-titanium alloy esophageal stent 20 to be tested. Each temperature recorder 50 is inserted into the heat-conducting liquid 61, and the distance between the inserted part and the nickel-titanium alloy esophageal stent 20 to be tested is 1 cm.

[0080] The magnetic stirrer 90 is disposed in a region between the inner bottom wall of the container 60 , the lower surface of the carrier 40 , and the support column 41 .

[0081] The data processing system 80 (software program) is signal-connected to both the force sensor 10 and the temperature recorder 50 .

[0082] Example 2

[0083] The present embodiment provides a device for measuring the phase change recovery temperature of a nickel-titanium alloy esophageal stent, which includes a force sensor 10, a nickel-titanium alloy esophageal stent 20 to be tested, a test auxiliary component 30, a carrier 40, a temperature recorder 50, a container 60, a heating component 70, an agitator 90 and a data processing system 80.

[0084] The carrier 40 is a carrier plate made of POM material. When in use, the carrier plate is located inside the container 60 and above the inner bottom wall of the container 60. There are four support columns 41, each of which is 5 cm in height. The four support columns 41 are respectively connected to the four corners of the carrier plate. The four corners of the carrier plate are respectively provided with a card slot, and the outer wall of each support column 41 has a card block that matches the above card slot one by one. The other end of each support column 41 is bonded to the inner bottom wall of the container 60.

[0085] The test auxiliary component 30 is a baffle made of POM material, which is spaced above the carrying plate.

[0086] The nickel-titanium alloy esophageal stent 20 to be tested is placed on the upper surface of the support plate at a position corresponding to the central area of ​​the water tank, and the spacing distance between the baffle and the support plate is smaller than the diameter of the nickel-titanium alloy esophageal stent 20 to be tested before phase change (50% of the nominal value of the measurement position).

[0087] After placement, the nickel-titanium alloy esophageal stent 20 to be tested is completely located on the upper surface of the support plate, without any part extending out of the support plate; the baffle is on the plane where its cross section is located, and can cover the projection of the nickel-titanium alloy esophageal stent 20 to be tested on the plane. Specifically, the nickel-titanium alloy esophageal stent 20 to be tested is tubular, with an outer diameter of 18 mm and a length of 120 mm. Accordingly, the dimensions of the support plate and the baffle are: 180 mm long, 40 mm wide, and 5 mm thick.

[0088] The lower end of the force sensor 10 is connected to the upper surface of the baffle through the first connecting member 11 (first connecting rod), one end of the first connecting rod is clamped with the baffle (the baffle is provided with a clamping groove, and the outer wall of the first connecting rod has a clamping block that cooperates with the above-mentioned clamping groove), and the other end is clamped with the force sensor 10. The force sensor 10 is made of metal, and the accuracy of the force sensor 10 is preferably not less than ±0.05N.

[0089] A second connecting member 12 (second connecting rod) is clamped on the upper end of the force sensor 10. One end of the second connecting rod away from the force sensor 10 is connected to a beam 13 fixed to a wall 14. The second connecting rod and the first connecting rod are collinear in the vertical direction.

[0090] The container 60 is an acrylic water tank, which contains a heat-conducting liquid 61 (anhydrous ethanol) with an initial temperature of -60°C, and the heat-conducting liquid 61 immerses the nickel-titanium alloy esophageal stent 20 to be tested. The heating element 70 is a temperature heating platform made of metal and equipped with a software control system, and the container 60 is placed on the surface of the heating element 70.

[0091] The temperature recorders 50 are four Precision RC-4 temperature recorders 50, which are symmetrically arranged on the left and right front and back sides of the nickel-titanium alloy esophageal stent to be tested 20. Each temperature recorder 50 extends into the heat-conducting liquid 61, and the distance between the extending part and the nickel-titanium alloy esophageal stent to be tested 20 is 2 cm.

[0092] The magnetic stirrer 90 is disposed in a region between the inner bottom wall of the container 60 , the lower surface of the carrier 40 , and the support column 41 .

[0093] The data processing system 80 (software program) is signal-connected to both the force sensor 10 and the temperature recorder 50 .

[0094] Example 3

[0095] This embodiment provides a method for measuring the phase change recovery temperature of a nickel-titanium alloy esophageal stent, which comprises the following steps:

[0096] The measuring device provided in the above-mentioned embodiment 1 or embodiment 2 is used, the heating element 70 is turned on to heat the heat-conducting liquid 61 in the container 60, and the agitator 90 is turned on at the same time, and the buoyancy of the supporting element 40 and the test auxiliary element 30 when the nickel-titanium alloy esophageal stent 20 to be tested is reset to zero, and then the nickel-titanium alloy esophageal stent 20 to be tested is placed, and the volume of the nickel-titanium alloy esophageal stent 20 to be tested is gradually expanded as the temperature of the heat-conducting liquid 61 increases (that is, the nickel-titanium alloy esophageal stent 20 to be tested will continue to restore its shape before compression as the temperature continues to increase). The heating rate of the heat-conducting liquid 61 is 2°C / min. When the nickel-titanium alloy esophageal stent 20 to be tested expands, the volume of the nickel-titanium alloy esophageal stent 20 to be tested gradually expands as the temperature of the heat-conducting liquid 61 increases. When the diameter is larger than the distance between the test aid 30 and the supporting member 40, the volume of the nickel-titanium alloy esophageal stent 20 to be tested squeezes the test aid 30 upwards during the continued expansion process and obtains the corresponding force value through the force sensor 10. This process can correspond to a curve graph of the force values ​​corresponding to different times (the horizontal axis corresponds to the force value, and the vertical axis corresponds to the temperature). When the value of the force sensor 10 does not change with the increase in the temperature of the heat-conducting liquid 61 for the first time, the temperature of the heat-conducting liquid 61 is increased by at least 10°C. If the value of the force sensor 10 no longer changes, the measurement is terminated, and the temperature of the heat-conducting liquid 61 at this time is used as the phase change recovery temperature of the nickel-titanium alloy esophageal stent.

[0097] Test Example 1

[0098] After measuring with the measuring device provided in Example 1 according to the measuring method provided in Example 3, the result is: the phase change recovery temperature of the nickel-titanium alloy esophageal stent 20 to be measured in Example 1 is 17.1°C.

[0099] After measuring with the measuring device provided in Example 2 according to the measuring method provided in Example 3, the result is: the phase change recovery temperature of the nickel-titanium alloy esophageal stent 20 to be measured in Example 2 is 15.3°C.

[0100] According to the measurement method in the prior art, the phase change recovery temperature of the nickel-titanium alloy esophageal stent 20 to be tested provided in Example 1 and Example 2 was measured using an Af point tester, and the results showed that the phase change recovery temperature of the nickel-titanium alloy esophageal stent 20 to be tested in Example 1 was 17.2°C, and the phase change recovery temperature of the nickel-titanium alloy esophageal stent 20 to be tested in Example 2 was 15.3°C.

[0101] It can be seen that the phase change recovery temperature of the nickel-titanium alloy esophageal stent 20 to be tested obtained by the measurement method provided in the present application has no significant difference from the result obtained in the prior art, which proves that the measurement method provided in the present application is feasible.

[0102] Test Example 2

[0103] A nickel-titanium alloy esophageal stent with a known phase change recovery temperature was used as a test sample, and measurements were performed according to the method provided in Example 3 (refer to Example 1 for the specific device) and the method of measuring using an Af point tester in the prior art. The results showed that the phase change recovery temperature measured by the method provided in the present application is closer to the actual phase change recovery temperature of the nickel-titanium alloy esophageal stent than that measured by the method provided by the prior art.

[0104] This shows that the method provided by the present application has higher accuracy than the prior art.

[0105] In summary, the device for measuring the phase change recovery temperature of the nickel-titanium alloy esophageal stent provided in the present application has a simple structure, is easy to manufacture, and has a low cost. The corresponding measurement method is easy to operate, highly efficient, and produces accurate results.

[0106] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A device for measuring the phase change recovery temperature of a nickel-titanium alloy esophageal stent, characterized in that: Including force sensor, test accessories, load-bearing parts, temperature recorder, container, heating element and data processing system; In the use state, the support member is connected to the inner bottom wall of the container through a support column, the test auxiliary member is spaced above the support member, the force sensor is connected to the top of the test auxiliary member through a first connecting member, the nickel-titanium alloy esophageal stent to be tested is used to be carried on the upper surface of the support member, and the spacing distance between the test auxiliary member and the support member is smaller than the diameter of the nickel-titanium alloy esophageal stent to be tested before the phase change, so as to ensure that the nickel-titanium alloy esophageal stent to be tested can contact the test auxiliary member during the expansion process and generate an upward force on the test auxiliary member, so that the force sensor can sense the corresponding force; The container is filled with a heat-conducting liquid, and during the measurement process, the heat-conducting liquid covers the nickel-titanium alloy esophageal stent to be tested; the container is in contact with the surface of the heating element and the container is placed on the upper surface of the heating element; The temperature measuring part of the temperature recorder extends into the area of ​​the container for containing the heat-conducting liquid to record the temperature of the heat-conducting liquid; The data processing system is connected to the force sensor signal.

2. The measuring device according to claim 1, characterized in that The measuring device also includes a nickel-titanium alloy esophageal stent to be tested, and the nickel-titanium alloy esophageal stent to be tested is carried on the upper surface of the carrying member.

3. The measuring device according to claim 1, characterized in that The number of the temperature recorders is not less than 2.

4. The measuring device according to claim 3, characterized in that A plurality of temperature recorders are arranged at intervals along the circumference of the container.

5. The measuring device according to claim 3, characterized in that When the number of the temperature recorders is an even number, the even number of temperature recorders are symmetrically arranged with the nickel-titanium alloy esophageal stent to be tested as a symmetry axis.

6. The measuring device according to claim 1, characterized in that The distance between the temperature recorder and the nickel-titanium alloy esophageal stent to be tested is 1-2 cm.

7. The measuring device according to claim 1, characterized in that The heat-conducting liquid is anhydrous ethanol.

8. The measuring device according to claim 7, characterized in that The initial temperature of the heat-conducting liquid is not higher than -50°C.

9. The measuring device according to claim 1, characterized in that The measuring device further comprises a stirrer, which is arranged in a region between the inner bottom wall of the container, the lower surface of the bearing member and the support column.

10. The measuring device according to claim 1, characterized in that The data processing system is also connected to the temperature recorder by signal.

11. The measuring device according to claim 1, characterized in that The measuring device further comprises a second connecting member, one end of which is connected to the force sensor, and the other end of which is connected to the outside world so that the force sensor is in a vertical state during use.

12. A method for measuring the phase change recovery temperature of a nickel-titanium alloy esophageal stent, characterized in that: The method comprises the following steps: using the measuring device described in any one of claims 1 to 11, turning on the heating element to heat the heat-conducting liquid in the container, so that the volume of the nickel-titanium alloy esophageal stent to be tested gradually expands as the temperature of the heat-conducting liquid increases, and when the diameter of the nickel-titanium alloy esophageal stent to be tested after expansion is greater than the distance between the test auxiliary component and the supporting component, the volume of the nickel-titanium alloy esophageal stent to be tested presses the test auxiliary component upward during continued expansion and obtains a corresponding force value through the force sensor, and when the value of the force sensor does not change as the temperature of the heat-conducting liquid increases, the temperature of the heat-conducting liquid at this time is used as the phase change recovery temperature of the nickel-titanium alloy esophageal stent.

13. The measuring method according to claim 12, characterized in that: When the value of the force sensor does not change with the increase of the temperature of the heat-conducting liquid, the temperature of the heat-conducting liquid is increased by at least 10°C. If the value of the force sensor does not change, the temperature of the heat-conducting liquid at this time is used as the phase change recovery temperature of the nickel-titanium alloy esophageal stent.

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