阅读说明：本技术 射频激励响应测量设备及传递函数测量系统 (Radio frequency excitation response measuring equipment and transfer function measuring system ) 是由 姜长青 龙天罡 李路明 于 2019-10-09 设计创作，主要内容包括：本发明公开了一种射频激励响应测量设备及传递函数测量系统,适用于直线构型试件,其中测量设备包括：底座,用于固定安装试件；激励输入部,固定安装在底座上,用于与试件电连接；移动部,安装在底座上且可沿试件长度方向移动,移动部上安装有测量线圈,测量线圈用于套设在试件上；响应输出部,与测量线圈电连接。通过在试件尖端施加射频激励,用测量线圈沿试件测量试件各处的激励响应,以此来计算试件的传递函数。进而可以采用试件例如植入物的传递函数来解耦植入物与人体模型,可以较为准确的对植入物和人体复杂的环境耦合进行模拟计算植入物的射频制热,较为准确的对植入物的射频制热进行评价。(The invention discloses a radio frequency excitation response measuring device and a transfer function measuring system, which are suitable for a linear configuration test piece, wherein the measuring device comprises: the base is used for fixedly mounting a test piece; the excitation input part is fixedly arranged on the base and is used for being electrically connected with the test piece; the moving part is arranged on the base and can move along the length direction of the test piece, and a measuring coil is arranged on the moving part and is used for being sleeved on the test piece; and the response output part is electrically connected with the measuring coil. The transfer function of the specimen is calculated by applying radio frequency excitation at the tip of the specimen and measuring the excitation response at various locations along the specimen with the measurement coils. Furthermore, the transfer function of the test piece such as the implant can be adopted to decouple the implant and the human body model, the coupling of the implant and the complex environment of the human body can be simulated and calculated accurately, and the radio frequency heating of the implant can be evaluated accurately.)

1. A radio frequency excitation response measuring apparatus adapted for use with a linear configuration test piece, comprising:

the base is used for fixedly mounting the test piece;

the excitation input part is fixedly arranged on the base and is used for being electrically connected with the test piece;

the moving part is arranged on the base and can move along the length direction of the test piece, and a measuring coil is arranged on the moving part and is used for being sleeved on the test piece;

a response output electrically connected to the measurement coil.

2. The measurement device of claim 1, further comprising: the measuring coil fixing part is arranged on the moving part, one end of the measuring coil fixing part is provided with a first groove for fixing the measuring coil, and the bottom of the first groove is provided with a through hole which is concentric with the first groove and is suitable for the test piece to pass through;

and the measuring coil fixing part is also provided with a second groove for fixing the response output part, and the second groove is communicated with the first groove.

3. The measurement device of claim 2,

the measuring coil is in interference fit with the first groove and/or the response output part is in interference fit with the second groove.

4. The measurement device of claim 1, further comprising:

one end of the supporting part is movably arranged on the moving part, and the other end of the supporting part is movably supported on one side of the test piece facing the base;

the measuring coil is matched with the supporting part to move.

5. The measurement device according to claim 4, wherein the support portion comprises:

a first support unit, a second support unit and a retractable and extendable extension device connecting the first support unit and the second support unit;

wherein the coil is arranged between the first support element and the second support element, the measuring coil being movable with the first support element and/or the second support element when the extension device is tightened or stretched.

6. The measurement device of claim 1, wherein the base comprises:

the test piece fixing device comprises a first guide rail, wherein two test piece fixing parts are arranged on the first guide rail and are respectively used for fixing two ends of a test piece, and at least one of the two test piece fixing parts can move along the guide rail and can be fastened on the first guide rail through a first fastening part.

7. The measurement device of claim 6, further comprising:

and the excitation connecting part is arranged on one fixing part and comprises a conductor unit and a wrapping unit wrapped outside the conductor unit, and the excitation input part and one end of the test piece are electrically connected on the conductor unit.

8. The measurement device of claim 7, wherein the conductor unit comprises:

a first cavity in interference fit with the excitation input;

and the second cavity is arranged on the outer side of the first cavity and is in interference fit with one end of the test piece.

9. The measurement device of claim 7, wherein the conductor unit comprises:

the protruding structure of the T-shaped gasket is a hollow structure and is in interference fit with the excitation input part;

and one end of the first elastic locking piece is used for locking the protruding structure, and the other end of the first elastic locking piece is used for locking one end of the test piece.

10. The measurement device of claim 7, wherein the conductor unit comprises:

one end of the third cavity is in interference fit with the excitation input part, and the other end of the third cavity is in interference fit with one end of the test piece;

the excitation connecting part further comprises a second elastic locking piece which is fixedly arranged on the inner side of the wrapping unit, and when one end of the test piece is inserted into the third cavity, the second elastic locking piece locks the test piece.

11. The measurement device of claim 1,

the magnetic core of the measuring coil is an iron-silicon-aluminum magnetic core, and the number of winding turns of the measuring coil is 3-10.

12. A transfer function measurement system adapted for use with a linear configuration test piece, comprising:

a radio frequency excitation response measurement device according to any one of claims 1 to 11;

an analyzer having an excitation port coupled to the excitation input and a response input port coupled to the response output for calculating a transfer function of the implant from the response measured by the measurement device.

Technical Field

The invention relates to the technical field of radio frequency testing, in particular to radio frequency excitation response measuring equipment and a transfer function measuring system.

Background

The radio frequency heating phenomenon of the conductor, especially the conductor in a linear configuration, can occur under the radiation of the radio frequency field, and in some application scenarios, the radio frequency heating phenomenon may have serious consequences. For example, when an implantable medical device, such as a cardiac pacemaker, a defibrillator, a vagus nerve machine, a cerebral pacemaker or a spinal cord stimulator, is installed in a patient, when the patient is scanned by magnetic resonance, the implantable medical device generates a radio frequency heating phenomenon under the action of the magnetic resonance, and particularly, when a conductor implant which has a slender conductive structure and is in contact with human tissues, the radio frequency heating phenomenon is more serious under the radiation of a radio frequency field. Therefore, the evaluation of radio frequency heating is an important ring for studying the magnetic resonance compatibility characteristics of implants.

Due to the fact that the implant and the complex environment of the human body are coupled, the radio frequency heating of the implant is difficult to be directly simulated and calculated, and therefore the radio frequency heating of the implant is difficult to be accurately evaluated.

Disclosure of Invention

In order to evaluate the radio frequency heating of the implant more accurately, the invention provides radio frequency excitation response measuring equipment and a transfer function measuring system.

According to a first aspect, embodiments of the present invention provide a radio frequency excitation response measuring apparatus, suitable for a linear configuration test piece, comprising: the base is used for fixedly mounting a test piece; the excitation input part is fixedly arranged on the base and is used for being electrically connected with the test piece; the moving part is arranged on the base and can move along the length direction of the test piece, and a measuring coil is arranged on the moving part and is used for being sleeved on the test piece; and the response output part is electrically connected with the measuring coil.

Optionally, the radio frequency excitation response measuring apparatus further comprises: the measuring coil fixing part is arranged on the moving part, one end of the measuring coil fixing part is provided with a first groove for fixing the measuring coil, and the bottom of the first groove is provided with a through hole which is concentric with the first groove and is suitable for a test piece to pass through; the measuring coil fixing part is also provided with a second groove for fixing the response output part, and the second groove is communicated with the first groove.

Optionally, the measurement coil is in interference fit with the first recess and/or the response output is in interference fit with the second recess.

Optionally, the radio frequency excitation response measuring apparatus further comprises: one end of the supporting part is movably arranged on the moving part, and the other end of the supporting part is movably supported on one side of the test piece facing the base; the measuring coil is matched with the supporting part to move.

Optionally, the support portion comprises: a first support unit, a second support unit and a retractable and extendable extension device connecting the first support unit and the second support unit; wherein the coil is arranged between the first support unit and the second support unit, and the measuring coil can move along with the first support unit and/or the second support unit when the extension device is tightened or extended.

Optionally, the base comprises: the test device comprises a first guide rail, wherein two test piece fixing parts are arranged on the first guide rail and are respectively used for fixing two ends of a test piece, at least one of the two test piece fixing parts can move along the guide rail and can be fastened on the first guide rail through a first fastening part.

Optionally, the radio frequency excitation response measuring apparatus further comprises: and the excitation connecting part is arranged on one fixing part and comprises a conductor unit and a wrapping unit wrapped outside the conductor unit, and the excitation input part and one end of the test piece are electrically connected on the conductor unit.

Optionally, the conductor unit comprises: a first cavity in interference fit with the excitation input; and the second cavity is arranged outside the first cavity and is in interference fit with one end of the test piece.

Optionally, the conductor unit comprises: the T-shaped gasket is in a hollow structure, and is in interference fit with the excitation input part; one end of the first elastic locking piece is used for locking the protruding structure, and the other end of the first elastic locking piece is used for locking one end of the test piece.

Optionally, the conductor unit comprises: one end of the third cavity is in interference fit with the excitation input part, and the other end of the third cavity is in interference fit with one end of the test piece; the excitation connecting part further comprises a second elastic locking piece which is fixedly arranged on the inner side of the wrapping unit, and the second elastic locking piece locks the test piece when one end of the test piece is inserted into the third cavity.

Optionally, the magnetic core of the measurement coil is a sendust magnetic core, and the number of turns of the winding of the measurement coil is 3-10.

According to a second aspect, embodiments of the present invention provide a transfer function measurement system, adapted to a linear configuration test piece, including: the radio frequency excitation response measuring device of any one of the above first aspects; an analyzer having an excitation port connected to the excitation input and a response input port connected to the response output for calculating a transfer function of the implant from the response measured by the measurement device.

The invention has the beneficial effects that:

the test piece is arranged on the base and is electrically connected with the excitation input part, the moving part is provided with the measuring coil, the measuring coil is sleeved on the test piece, after excitation is input to the test piece by the excitation input part, all parts of the test piece generate excitation, the moving part drives the measuring coil to stably move relative to the test piece when moving along the length direction of the test piece, the coil induces excitation response of all positions of the test piece in the moving process, the response is output in real time through the response output part, and radio frequency excitation is applied to the tip of the test piece, and the measuring coil is used for measuring the excitation response of all positions of the implant along the test piece, so that the transfer function of the test piece is calculated. Furthermore, the transfer function of the test piece such as the implant can be adopted to decouple the implant and the human body model, the coupling of the implant and the complex environment of the human body can be simulated and calculated accurately, and the radio frequency heating of the implant can be evaluated accurately.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 shows a schematic diagram of a radio frequency excitation response measuring apparatus of the present embodiment;

FIG. 2 is a schematic view showing a specimen fixing portion of the present embodiment;

FIG. 3 is a schematic view showing a specimen fixing hole of the present embodiment;

FIG. 4 shows a schematic view of an excitation connection of the present embodiment;

FIG. 5a shows a schematic view of another excitation connection of the present embodiment;

FIG. 5b shows a schematic view of a wrapping unit of another excitation connection of the present embodiment;

FIG. 5c shows a schematic view of a conductor element of another excitation connection of the present embodiment;

FIGS. 6a to 6d are schematic views showing another excitation connection portion of the present embodiment;

FIGS. 7a to 7c are schematic views showing another excitation connection portion of the present embodiment;

FIGS. 8a and 8b are graphs showing response measurements for the present embodiment;

fig. 9 a-9 c show schematic views of the support part of the present embodiment;

FIGS. 10 a-10 c show schematic views of another support portion of the present embodiment;

fig. 11 shows a schematic view of a measurement coil fixing part of the present embodiment;

fig. 12 is a schematic view showing another measurement coil fixing part of the present embodiment;

FIG. 13 shows a schematic view of a slider of the present embodiment;

FIG. 14 is a schematic view showing the base and the parallel dual rails according to the present embodiment;

fig. 15 shows a schematic diagram of the transfer function measurement system of the present embodiment.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As background art, the radio frequency heating of a conductor with a linear configuration is difficult to perform analog computation in some application scenarios, for example, in an implantable medical device, because the coupling between an implant and a complex environment of a human body is difficult to perform analog computation of the radio frequency heating of the implant directly, the inventors have found through research that a transfer function of the implant can be used to decouple the implant and a human body model, and the coupling between the implant and the complex environment of the human body can be more accurately performed to perform analog computation of the radio frequency heating of the implant. Specifically, the final result of the rf heating can be equivalent to: the electric field state of the implant position when the implant is not arranged is used as an excitation, and the electric field state is applied to the corresponding position of the implant to generate a response at the tip of the implant. The stimulus to which the implant is subjected can be calculated by simulation, and the response of the implant to this stimulus can be verified against each other by simulation calculations and experimental measurements. The overall excitation experienced by the implant can be equivalent to a superposition of an infinite number of small excitations that are end-to-end along the implant direction, where the ratio of the excitation response at each position of the implant to the response it produces at the tip of the implant is defined as the transfer function. Based on the discovery that accurate measurement of the excitation response throughout the implant is the key factor in the evaluation of rf heating, the inventors have developed an rf excitation response measurement device that is suitable for use with a straight configuration trial, such as an elongated straight configuration implant or cable, by applying rf excitation at the tip of the implant and measuring the excitation response throughout the implant along the implant with a toroidal inductor to calculate the transfer function of the implant. In particular, reference may be made to the measurement apparatus shown in fig. 1, which can measure an elongated conductor in a linear configuration, and in this embodiment, it is exemplified that the measurement apparatus measures an implant in a linear configuration, and for the accuracy of the measurement result, the measurement process needs to simulate the human environment, so that the measurement apparatus can be placed in a container (not shown in the figure) containing saline solution, and the measurement apparatus can include:

the base 1 is used for fixedly mounting a test piece 9; the excitation input part 8 is fixedly arranged on the base 1 and is used for being electrically connected with the test piece 9; the moving part 10 is movably arranged on the base 1, the measuring coil 6 is arranged on the moving part 10, and the measuring coil 6 is used for being sleeved on the test piece 9; the response output 7 is electrically connected to the measuring coil 6.

The test piece is arranged on the base and is electrically connected with the excitation input part, the moving part is provided with the measuring coil, the measuring coil is sleeved on the test piece in a non-contact mode, after excitation is input to the test piece by the excitation input part, all parts of the test piece generate excitation, the moving part moves along the length direction of the test piece to drive the measuring coil to move relative to the test piece in a non-contact mode, the coil induces excitation response of all positions of the test piece in the moving process, the response is output in real time through the response output part, radio frequency excitation is applied to the tip of the test piece, and the measuring coil is used for measuring the excitation response of all the positions of the test piece along the test piece, so that the transfer function of the test piece is. Furthermore, the transfer function of the test piece such as the implant can be adopted to decouple the implant and the human body model, the coupling of the implant and the complex environment of the human body can be simulated and calculated accurately, and the radio frequency heating of the implant can be evaluated accurately.

In some exemplary embodiments, the base 1 may be a rectangular plate-shaped base 1, and it should be understood by those skilled in the art that the base 1 may be a base of any shape, as long as the base capable of stabilizing the measuring apparatus is within the protection scope of the present embodiment, and a specimen fixing portion for fixing the specimen 9 may be disposed on the base 1, and in some exemplary embodiments, for example, in the measuring apparatus shown in fig. 1, the specimen fixing portion 2 may include two portions for respectively fixing two ends of the specimen 9 to support the specimen 9 so that the specimen 9 is in a straight state, thereby facilitating measurement. In some optional embodiments, in order to adapt to test pieces 9 with different lengths, as an optional embodiment, as shown in fig. 1, a first guide rail 11 is further installed on the base 1, the first guide rail 11 may be fixedly laid on the base 1 along the length direction of the base 1, and the first guide rail 11 may also be integrally formed with the base 1. The test piece fixing parts 2 can be arranged on the first guide rail 11, at least one of the two test piece fixing parts 2 can move along the guide rail to adjust the distance between the two test piece fixing parts 2, and the test piece fixing part 2 can be fastened on the first guide rail 11 through the first fastening part after the distance between the test piece fixing parts 2 is adjusted.

As shown in fig. 2, the specimen fixing portion 2 may include a specimen fixing hole 21, a specimen fastener mounting hole 22, and a first fastener mounting hole 23, wherein the specimen 9 may pass through the specimen fixing hole 21, and a specimen 9 fastener is mounted through the specimen fastener mounting hole 22 to fix one end of the specimen 9 in the specimen fixing hole 21, in this embodiment, as shown in fig. 3, the specimen fixing hole 21 may be in a drop shape, the specimen 9 fastener may be a bolt, and the first fastener may also be a bolt. Specifically, the fixing process of the test piece 9 may be: the two test piece fixing parts 2 are fixedly arranged on the first guide rail 11 and are respectively positioned at two ends of the test piece 9, and the two ends of the test piece 9 are fixed in the test piece fixing holes 21 through the test piece 9 fasteners. The specimen fixing portion 2 is placed in an appropriate position on the first rail 11 according to the length of the specimen 9, and is fixed with the first rail 11 by the first fastener. In the present embodiment, the specimen-fixing portion 2 may further include a neck portion 24, and the specimen-fixing hole 21 is opened at a tip end of the neck portion 24. As an alternative embodiment, the height of the neck 24 may be adjusted to allow the test piece 9 to be measured at different height positions. In addition, the specimen holder 2 may include a plurality of pairs of necks 24, and the necks 24 of each pair are different in height and are replaced when the specimen 9 needs to be measured at different heights.

In some exemplary embodiments, the excitation input portion 8 may be an excitation cable, and the excitation cable may be a standard semi-rigid cable used in radio frequency testing, and the type is selected according to actual situations. In order to ensure a stable connection to the test piece 9, the excitation input 8 can be fixedly mounted on the base 1. As an alternative embodiment, as shown in fig. 1, the excitation input part 8 may be fixed on the base 1 by an excitation connection part 3, and in this embodiment, the excitation connection part 3 is provided on the base 1 at one end of the test piece 9, so that the excitation input part 8 is fixed on the excitation input part 8 fixing device and is stably electrically connected with one end of the test piece 9.

In some alternative embodiments, as shown in fig. 4, the excitation connecting portion 3 may include an excitation input fixing hole 31, and the excitation input fixing hole 31 may also be shaped as a water drop-shaped hole as shown in fig. 3. And the length of the excitation input portion fixing hole 31 is greater than the length of the specimen fixing hole 21 in the longitudinal direction of the excitation input portion 8, or the longitudinal direction of the specimen 9, in order to fix the excitation input portion 8 better, and also in order to obtain a longer measurement range of the specimen 9. The excitation input is secured within the fastening hole 32 by an excitation input fastener, such as a bolt. The two planes of the bolt, fastening hole 32 fix three degrees of freedom, determining the position of the excitation input 8 in this plane. The excitation input portion 8 can be fixed at two points by passing the excitation input portion 8 through the long excitation connecting portion hole 31, and as shown in fig. 4, the excitation input portion 8 can be fixed by two bolts, and two rotational degrees of freedom of the excitation input portion 8 are restricted. An axial rotational degree of freedom is reserved for the excitation input part 8, and the angle can be adjusted according to actual conditions. The excitation connection 3 provides a good fixation for excitation inputs 8 of a range of diameters. The excitation linkage 3 may be slid into place along the first rail 11 and a third fastener may be installed through the third fastener installation hole 33 to be secured to the first rail 11. As an exemplary embodiment, the excitation connection 3 may employ a standard interface, including but not limited to an N-type connector, an M-type connector, an SMA connector, a BNC connector, etc.

As an exemplary implementation, the excitation connecting portion 3 may also adopt a structure as shown in fig. 5a-c, specifically, the excitation connecting portion includes a conductor unit 35 and a wrapping unit 36 wrapped outside the conductor unit 35; wherein the conductor unit 35 comprises a first cavity 351 for receiving the excitation input 8 and at least one second cavity 352 for receiving an end of the test piece 9. The conductor unit 35 is used for achieving electrical connection of the excitation input portion 8 and the test piece 9, the conductor unit 35 is used for achieving short circuit of a wire core and a shielding layer of the excitation input portion 8, the wrapping unit 36 wraps the conductor unit 35, the wrapping unit is made of insulating materials with certain mechanical strength, fixing of all components is achieved, as an exemplary implementation, the outer materials can be made of acrylic materials, and the wrapping unit 36 arranged outside the conductor unit 35 can effectively achieve signal dissipation of the connection position of the excitation input portion 8 and the test piece 9. As an exemplary embodiment, the first cavity 351 may accommodate a wire core of the excitation input 8, wherein the wire core of the excitation input 8 is in interference fit with the first cavity 351 to ensure that the conductor unit 35 has good contact with the wire core of the excitation input 8, ensuring stability of the signal. As shown in fig. 5a and 5c, the second cavities 352 are disposed at the periphery of the first cavity 351, wherein the second cavities 352 shown in fig. 5a and 5c are a plurality of second cavities 352 formed by plate-shaped structures, the test piece 9 can be placed in any one of the second cavities 352, the size of each second cavity 352 can be the same or different, and the figure exemplarily shows the case of six equally large cavities. In practical applications, the number and size of the second cavities 352 may be selected according to actual conditions to adapt to different test pieces 9. The fixation of the test piece 9 and the second cavity 352 can be realized by interference fit, and can also be realized by adding screws for fixation.

As an exemplary implementation, the excitation connecting portion 3 may also adopt a structure as shown in fig. 6a-d, specifically, the excitation connecting portion includes a conductor unit 35 and a wrapping unit 36 wrapped outside the conductor unit 35; wherein the conductor unit 35 includes: the T-shaped gasket 353 comprises a base 3531 and a protruding structure 3532, wherein the protruding structure 3532 of the T-shaped gasket 353 is a hollow structure and is in interference fit with the excitation input part 8, as can be seen in fig. 6a and 6 b. A first resilient locking member 354, one end of which is adapted to lock with the projecting structure and the other end of which is adapted to lock with an end of the test piece 9, can be seen in particular in fig. 6a and 6 c. Wherein figure 6a shows the situation after the excitation input 8 and the test piece 9 have been mated with the excitation connection. As an exemplary embodiment, the first resilient locking member 354 may be a spring having a radius slightly smaller than the outer diameter of the protruding structure 3532 of the T-shaped gasket 353 to achieve relative locking. The outer diameter of the spring is slightly smaller than one end of the test piece 9, and the spring can be automatically locked when one end of the test piece 9 is inserted into the spring. As shown in FIG. 6d, the wrapping unit comprises an acrylic shell 361 (with certain strength, conductivity 0S/m, dielectric constant 3.7) and a silicone rubber elastic structure 362 (solid, with certain elasticity, conductivity 0S/m, dielectric constant 2-3). The acrylic housing 361 fixes the relative positions of the excitation input part 8, the T-shaped gasket 353 and the silicon rubber elastic structure 362; the silicone rubber elastic structure 362 makes the spring fixed in the radial direction, only has freedom along the axial direction, and only changes the radius when the cable to be tested is inserted.

As an exemplary embodiment, the excitation connecting portion 3 may also adopt a structure as shown in fig. 7a-c, specifically, the excitation connecting portion includes a conductor unit 35 and a wrapping unit 36 wrapped outside the conductor unit 35; wherein the conductor unit 35 includes: and one end of the third cavity is in interference fit with the excitation input part 8, and the other end of the third cavity is in interference fit with one end of the test piece 9. In this embodiment, the conductor unit 32 may be a hollow conductor tube with one end inserted into the excitation input portion 8 and one end inserted into one end of the test piece 9. In order to fasten the test piece 9, in this embodiment, the excitation connecting part further includes a second elastic locking piece 363 fixedly disposed inside the wrapping unit, and the second elastic locking piece 363 locks the test piece 9 when one end of the test piece 9 is inserted into the third cavity. The second elastic locking piece 363 can be an elastic sheet fixed on the inner side of one end of the wrapping unit 36, and after the cable to be tested is inserted, the elastic sheet is compressed, compresses the cable to be tested, and fixes the position of the cable to be tested. The number of the resilient pieces is selected according to actual requirements, and three resilient pieces are exemplarily shown in fig. 7 a-c. Reference may be made to fig. 7b, which shows the state of the second elastic locking member 363 before the insertion of the test piece 9, and fig. 7c, which shows the state of the second elastic locking member 363 after the insertion of the test piece 9.

In the present embodiment, a comparative test is performed on the connection condition of the test piece 9 and the excitation input section 8 including the structure and volume of the excitation connection section. The influence of various conditions at the excitation position is evaluated in a simulation calculation mode, and the test results are shown in fig. 8a and 8b, which correspond to the radius (0.365mm-0.73mm) of the excitation cable of different excitation input parts 8, the exposed contact length (2mm, 5mm and 10mm) of different excitation ends, the wrapping type excitation and the wrapping type excitation end made of acrylic materials. From the calculation results of the upper graph, it can be found that the increase of the wire diameter of the excitation cable increases the energy dissipation and reduces the signal intensity entering the cable to be measured, and the wrapped excitation has a similar phenomenon due to a slightly larger radius, but the influence is relatively insignificant. Wrapped-around excitation wrapped with acrylic material restores the signal strength into the cable to normal levels. The provision of the wrapping unit 36 outside the conductor unit 35 allows for a more efficient excitation of signal dissipation at the connection of the input 8 and the test piece 9.

The movable part 10 is movably arranged on the base 1, the measuring coil 6 is arranged on the movable part 10, and the measuring coil 6 is used for being sleeved on the test piece 9. The moving part 10 can move relatively to the test piece 9 along the length direction of the test piece 9 to drive the measuring coil 6 to move relative to the test piece 9, so as to conveniently measure the excitation response of each position of the test piece 9. As an alternative embodiment, the movement of the moving portion 10 may be driven by a driving mechanism, and the driving mechanism may specifically be a driving mechanism that drives the moving portion 10 to reciprocate along the length direction of the test piece 9 by a screw transmission, a pulley transmission, a rack-and-pinion transmission, or the like. Of course, the moving part 10 may also be moved by means of artificial waves. This embodiment is not limited.

In order to ensure that the measuring result is stable and accurate, the angle change amplitude and/or the position change amplitude between the measuring coil 6 and the test piece 9 are/is within a preset range during the movement of the measuring coil 6. In the present embodiment, the angle between the measuring coil 6 and the test piece 9 may be an angle between a plane in which a vertical cross section of the measuring coil 6 is located and the test piece 9. The position between the measurement coil 6 and the test piece 9 may be a distance from the test piece 9 to the measurement coil 6, and in the moving process of the measurement coil 6, the measurement coil 6 needs to be kept moving stably, and both the angle change and the position change are in small changes, for example, the angle change does not exceed 5 degrees, and the position change does not exceed 2mm, so as to ensure the stability and accuracy of the measurement. In some exemplary embodiments, during the movement of the measuring coil 6 along the length of the test piece 9, it is necessary to ensure that the measuring point on the test piece 9 is at the center of the measuring coil 6 and the test piece 9 is perpendicular to the plane of the measuring coil 6. The measuring coil 6 can be a circular coil, and the test piece 9 is concentric with the measuring coil 6, i.e. the measured point of the test piece 9 is located on the center of the measuring coil 6.

Since the test piece may be a flexible structure with a long length, in order to achieve that the angle change amplitude and/or the position change amplitude between the measurement coil 6 and the test piece 9 are/is within a preset range in the moving process of the measurement coil 6, as an exemplary embodiment, a support point needs to be added to the middle part of the test piece to ensure the linear configuration of the test piece on the premise that the stress in the test piece is proper. The currently used measuring coil is of an annular structure, and the measuring coil needs to be adjusted to a certain extent when passing through a supporting point, so that the measuring complexity is increased, and potential influence on a test result is brought. Therefore, as shown in fig. 7a and 8a, the measuring apparatus may further include a support portion 14, one end of which is movably disposed on the moving portion (not shown in the figure), and the other end of which is movably supported on a side of the test piece 9 facing the base; the measuring coil 6 moves in cooperation with the support 14, the support 14 can move along with the measuring coil 6, and the support points 144 can be added when measuring the middle part of the test piece 9 to ensure the straight configuration of the test piece 9.

To achieve that the middle portion of the test piece 9 always has the supporting point 144, as an exemplary embodiment, as shown in fig. 9b and 9c and fig. 10b and 10c, the supporting portion 14 may include: a first supporting unit 141, a second supporting unit 142, and a retractable and extendable extension device 143 connecting the first supporting unit 141 and the second supporting unit 142; wherein the coil is arranged between the first support element 141 and the second support element 142, the measuring coil 6 can follow the first support element 141 and/or the second support element 142 when the extension means 143 is tightened or extended.

Specifically, a supporting point 144 is provided between the first supporting unit 141 and the second supporting unit 142, the support point 144 may be coupled to both the first support element 141 and the second support element 142. as an exemplary embodiment, the support point 144 may be fixed to the test piece 9, wherein the first supporting unit 141 can stretch the extending device 143 towards a first direction, the second supporting unit 142 can stretch the extending device 143 towards a second direction, the first direction is opposite to the second direction, the supporting units for supporting are different when the measuring coil 6 is on different sides of the supporting point 144, for example, as shown in fig. 7b and 8b, when the measuring coil 6 is at the side of the supporting point 144 close to the first supporting unit 141, at this time, the measuring coil 6 moves along with the first supporting unit 141, the second supporting unit 142 is fixed, and the second supporting unit 142 is combined with the supporting point 144 to play a supporting role; when the measuring coil 6 approaches the second supporting unit 142 at the supporting point 144 as shown in fig. 9c and 10c, the measuring coil 6 follows the second supporting unit 142 to move, and the first supporting unit 141 is fixed and follows the second supporting unit 142 to move.

The operation of the support 14 will be described in an exemplary manner with reference to fig. 9b and 9c and fig. 10b and 10 c:

in this embodiment, the measuring coil 6 may be translated in a path along the test piece 9 using an automatic translation system or manually. When measuring the left side of the supporting point 144, the first supporting unit 141 and the left side extending device 143 of the supporting point 144 move together with the measuring coil 6 on the left side to realize the measurement, and the length of the right side extending device 143 serving as a support for the right side supporting element at the position of the supporting point 144 is changed continuously. When the vicinity of the supporting point 144 is measured, the extending devices 143 on both sides of the supporting point 144 are tightened and move together with the ring probe. When the first supporting unit 141 moves to the supporting point 144, the first supporting unit 141 is fixed (which can be realized by the relation with the moving part), the left extending device 143 is stretched, and the right extending device 143 is tightened and runs to the right together with the second supporting unit 142 and the measuring coil 6, so that the parameters of the right test piece 9 of the supporting point 144 are measured.

As an exemplary embodiment, the extension device 143 may be implemented by a mechanical structure, and may also be implemented by an elastically deformable material. Mechanisms include, but are not limited to, folding structures such as shown in fig. 10a-c, roller shade structures such as shown in fig. 10a-c, and the like that serve a similar purpose.

The measuring coil 6 generates excitation response by inducing excitation on the test piece 9 in the process of moving along the length direction of the test piece 9 under the driving of the moving part 10, and outputs the excitation response to the outside through the response output part 7 electrically connected. In some embodiments, the response output 7 may be a rigid cable electrically connected to the measurement coil 6, and in some exemplary embodiments, the response output 7 and the measurement coil 6 may be fixedly connected, e.g., may be soldered or glued together.

The measurement coil 6 outputs the induced response, i.e. the induced voltage, through the response output portion 7, in order to increase the amplitude of the output voltage, a person skilled in the art generally uses a coil with a large number of turns, because the more the number of turns of the coil, the larger the voltage generated by induction, however, the inventor has found through research that when the measurement coil 6 uses a high number of turns, the output response signal is very stray and discontinuous, resulting in inaccurate measurement result. Experiments show that when the number of turns of the winding of the measurement coil 6 is small, a response signal which is smooth and has a high signal amplitude can be obtained, in a preferred embodiment, the magnetic core material of the measurement coil 6 is sendust, and the number of turns of the winding is 3-10 turns, as shown in a response measurement result curve effect diagram shown in fig. 8a and 8b, the response measurement result curve effect diagram is a measurement result obtained when the magnetic core material is sendust and the number of turns of the winding is 5 turns. The measuring coil with less winding turns is adopted, stray influence can be reduced, impedance is reduced, influence among the coils is small, but in order to ensure the amplitude of a response signal, the number of the winding turns is not too small, and therefore, the coil with 3-10 winding turns is adopted in the embodiment.

As some exemplary embodiments, the moving part 10 may include a second guide rail 12 disposed opposite to the first guide rail 11, for example, the measuring apparatus shown in fig. 1, two ribs 13 may be disposed on both sides of the base 1, the first guide rail 11 is laid on the base 1, and the second guide rail 12 may be erected on the two ribs 13. As shown in fig. 1 and 14, the second guide rail 12 is arranged in parallel with the first guide rail 11. As an exemplary embodiment, as shown in fig. 1, a slide block 4 may be disposed on the second guide rail 12, and the slide block 4 may be movably disposed on the guide rail, specifically, the slide block 4 may be driven by the driving mechanism exemplified in the above embodiments to move on the second guide rail 12, or may be moved on the second guide rail 12 by manual toggling. As an alternative embodiment, the response output 7 is fixedly arranged on the slide 4, and the measuring coil 6 is fixedly connected to the response output 7. The support 7 may also be arranged on the second rail and may be fixed to the second rail by fastening means.

As another alternative embodiment, as shown in fig. 1, the moving part 10 further includes: and a measuring coil fixing part 5 provided on the slider 4. Fig. 11 shows a schematic diagram of the measuring coil fixing part 5, one end of which is provided with a first groove 51 for fixing the measuring coil 6, the measuring coil fixing part 5 is further provided with a second groove 52 for fixing the response output part 7, and the second groove 52 is communicated with the first groove 51. As shown in fig. 12, after the measurement coil 6 and the response output portion 7 are connected, they are placed in the first recess 51 of the measurement coil fixing portion 5, and the response output portion 7 is placed in the second recess 52, so that the measurement coil 6 and the first recess 51 and the response output portion 7 and the second recess 52 are in interference fit. The first recess 51 and the second recess 52 limit five degrees of freedom of the combination of the measuring coil 6 and the response output 7, and the interference fit ensures that the only remaining degree of freedom in the direction of the second guide rail 12 is well limited when the mechanical load is small.

Some measured test pieces 9 may be flexible test pieces 9, the flexible test pieces 9 are long in length, even if tension exists, the straight line configuration of the test pieces 9 is difficult to ensure, and in an alternative embodiment, as shown in fig. 9, the bottom of the first groove 51 is provided with a through hole 53 which is concentric with the first groove 51 and is suitable for the test pieces 9 to pass through; the through hole 53 can play a role in supporting the third point on the test piece 9, so that the linear configuration of the flexible test piece 9 can be better ensured.

For better mounting of the measuring coil fixing part 5, as shown in fig. 13, the slider 4 may include a first square hole 41, which is engaged with the second guide rail 12, so that the slider 4 can move freely on the second guide rail 12; and a second square hole 42 arranged perpendicular to the first square hole 41, through which the measuring coil fixing part 5 passes, is movable relative to the slider 4 to adjust the relative position of the measuring coil 6 and the test piece 9, and is mountable on a second fastener mounting hole 43 by a second fastener to fasten the measuring coil fixing part 5 on the slider 4. Wherein, the second fastener can also be a bolt.

Specifically, the two specimen fixing portions 2 of the specimen 9 are identical and are both located at the midpoint position in the width direction of the first guide rail 11, and the centers of the first grooves 51 of the specimen 9 and the measuring coil fixing portion 5 are collinear along the length direction of the specimen 9 through the specimen fixing portions 2. The slider 4 is used for limiting the measuring coil fixing part 5 through the second square hole 42, and the measuring coil 6 is ensured to be positioned at the middle point of the width direction of the first guide rail 11. According to the height of the test piece 9, after the measuring coil 6 is adjusted to a proper height by adjusting the height of the measuring coil fixing part 5, the second fastening device is fastened to fix the measuring coil fixing part 5 on the sliding block 4. During the measurement, the test piece 9 is to be centered in the measuring coil 6. For the flexible test piece 9, there is a curve over the entire path. In order to ensure that the flexible test piece 9 is also positioned at the midpoint of the measuring coil 6, through holes with different diameters are arranged in the first groove 51 of the measuring coil fixing part 5 according to the diameter of the test piece 9, so as to ensure the relative position of the test piece 9 and the measuring coil 6 to be stable during movement.

An embodiment of the present invention provides a transfer function measurement system, which is suitable for a linear configuration test piece, and as shown in fig. 15, the measurement system may include: the radio frequency excitation response measuring apparatus 100 as described in the above embodiments; an analyzer 200 having an excitation port 201 and a response input port 202, the excitation port 201 being connected to the excitation input 8 and the response input port 202 being connected to the response output 7 for calculating the transfer function of the implant from the responses measured by the measurement device 100.

The analyzer calculates the transfer function of the specimen by applying radio frequency excitation at the specimen tip, measuring the excitation response at various locations along the specimen with the measurement coil, and receiving the response. Furthermore, the transfer function of the test piece such as the implant can be adopted to decouple the implant and the human body model, the coupling of the implant and the complex environment of the human body can be simulated and calculated accurately, and the radio frequency heating of the implant can be evaluated accurately.

Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations fall within the scope defined by the appended claims.