High-adaptability detection device for lower limb lymphedema
By designing a lower limb lymphedema detection device with clamping and friction components, the problem of measurement error caused by manual operation is solved, realizing automated and accurate measurement of lower limb lymphedema, and adapting to the detection needs of patients with different body types.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-22
- Publication Date
- 2026-03-10
AI Technical Summary
In existing technologies, the measurement of lower extremity lymphedema relies on manual operation, which leads to inaccurate measurement results and errors, affecting the diagnosis of the condition and the formulation of treatment plans.
A device for detecting lower limb lymphedema was designed, employing a clamping component and a friction component to ensure that the measuring tape is aligned with the patient's lower limb and to control the tape's winding speed, thereby reducing the variability caused by manual operation. Automated measurement is achieved through a displacement sensor and a data processing module.
It improves the accuracy and consistency of measurement results, reduces the workload of testing personnel, shortens measurement time, and ensures consistency among different testing personnel and in different scenarios.
Smart Images
Figure CN121622015A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of lymphedema detection equipment, in particular to a high adaptability detection device for lower limb lymphedema. BACKGROUND
[0002] Lower limb lymphedema is a chronic disease caused by lymphatic system dysfunction, which leads to tissue fluid accumulation and lower limb swelling, commonly seen after infection, surgery, tumor treatment or congenital lymphatic abnormalities, and the main symptoms include lower limb swelling, skin hardening and limited mobility, which requires pressure therapy, physical therapy or surgery to improve circulation, and prevention of infection and skin damage. Lower limb lymphedema measurement is an important method to evaluate the degree of edema, which requires a soft tape to be measured horizontally around the fixed position, and the data of both sides are recorded for comparison.
[0003] In the prior art, when evaluating the degree of lower limb lymphedema of a patient, the patient's lower limb circumference needs to be measured. In the prior art, an inelastic soft tape is generally used as a measuring tool. The soft tape is wrapped horizontally around the measured part of the patient's lower limb, and the tightness of the soft tape is adjusted to the point where a finger can be inserted. Then, the circumference data of the corresponding positions of the patient's legs on both sides are recorded. During each measurement, the leg circumference data of the healthy side and the affected side of the patient's lower limb are recorded simultaneously to facilitate subsequent comparison and analysis of the changes in the degree of edema. However, this measurement process completely relies on the manual operation of the detection personnel, and the operation habits of different detection personnel differ. Even the same detection personnel cannot maintain the same operation intensity at different times, which may result in measurement errors and reduce the accuracy and reliability of the leg circumference measurement data. Inaccurate measurement data cannot provide a true and effective reference for the patient's condition for the doctor, which is not conducive to the doctor's accurate judgment of the patient's condition and has an adverse impact on the subsequent development of the treatment plan and adjustment. SUMMARY
[0004] Therefore, the present application aims to provide a high adaptability detection device for lower limb lymphedema to solve the technical problems in the background art.
[0005] To achieve the above-mentioned purpose, the present application provides the following technical solution: a high adaptability detection device for lower limb lymphedema, comprising a device main body, a soft tape installed on the inner wall of the device main body extending to the outside, one end of the soft tape fixedly connected to the outer wall of the device main body, the other end of the soft tape located inside the device main body and fixedly connected with a winding assembly, the winding assembly comprising a clock spring fixedly connected to one end of the soft tape, and the end of the clock spring fixedly connected with a rotating rod, one side of the winding assembly provided with a clamping assembly for limiting the soft tape, and the other side of the winding assembly provided with a friction assembly for slowing down the winding speed of the soft tape.
[0006] Preferably, the clamping assembly comprises a pressing block slidingly connected to the surface of the device body, the top end of the pressing block extends to the outer wall of the device body, the top end of the pressing block is fixedly sleeved with a first spring, and the top end of the first spring is fixedly connected to the top end of the inner wall of the device body, one side of the pressing block is attached with a moving block, the moving block is slidingly connected to the inner wall of the device body, and the contacting positions of the pressing block and the moving block are both provided with inclined surfaces.
[0007] Preferably, the side surface of the pressing block away from the moving block is provided with a V-shaped groove, the inner wall of the V-shaped groove is fixedly connected with a V-shaped block at the center position, the bottom end of the inner wall of the device body is rotatably connected with a limiting rod, the top end of the limiting rod is fixedly connected with a clamping block, and the clamping block is clamped in the inner wall of the V-shaped groove.
[0008] Preferably, the side surface of the moving block away from the pressing block is provided with two groups of clamping plates, the soft ruler is inserted between the two groups of clamping plates, one side surface of one group of the clamping plates is fixedly connected with a plurality of insertion rods, the outer wall of the insertion rod is sleeved with a second spring, and the second spring is fixedly connected with the moving block, and the side surface of the moving block is provided with an insertion slot matched with the insertion rod.
[0009] Preferably, the friction assembly comprises a resisting block slidingly connected to the surface of the device body, the bottom end of the resisting block is attached with an inclined block, the inclined block is slidingly connected to the inner wall of the device body, and the contacting positions of the resisting block and the inclined block are both provided with inclined surfaces.
[0010] Preferably, the top end of the winding assembly is fixedly connected with a first taper, one side of the first taper is provided with a second taper block, the surface of the inclined block is provided with a sliding groove, the outer wall of the second taper block is fixedly connected with a connecting rod extending to the inner wall of the sliding groove, the bottom end of the connecting rod is fixedly connected with a compression spring, and the bottom end of the compression spring is fixedly connected to the bottom end of the inner wall of the sliding groove.
[0011] Preferably, the upper surface of the resisting block is fixedly sleeved with an L-shaped extrusion rod, one end of the L-shaped extrusion rod is in contact with the upper surface of the second taper block, the top end of the resisting block extends to the outer wall of the device body, the outer wall of the resisting block is fixedly sleeved with a third spring at a position close to the top end, and the third spring is fixedly connected with the top end of the inner wall of the device body.
[0012] Preferably, the inner wall of the device body is connected with a rack through a torsional spring, the top end of the rack is fixedly connected with an arc-shaped block extending to the outer wall of the device body, the side surface of the resisting block close to the rack is connected with a limiting block through a torsional spring, and the limiting block is engaged with the rack.
[0013] Preferably, the inner wall of the device body is provided with a displacement sensor attached to the surface of the soft ruler on one side of the two groups of clamping plates, a circuit board and a data processing module are installed in the device body, and a display screen is installed on the upper surface of the device body.
[0014] In summary, the present application mainly has the following beneficial effects: 1、The present application realizes the pre-stretching and positioning of the flexible ruler through the clamping assembly, ensures that the flexible ruler is always aligned with the measured part of the lower limb of the patient, avoids the measurement deviation caused by the deviation and inclination of the flexible ruler during manual measurement, secondly, through the cooperative operation of the pressure block, the resistance block, the arc block and other components in the friction assembly, the stable regulation of the winding speed of the flexible ruler is realized, the deviation and inclination of the flexible ruler caused by the too fast shrinkage of the flexible ruler is prevented, the accuracy of the detection result is improved to a certain extent, during the detection process, the flexible ruler does not need to be manually held around the limb, only simple pressing and dialing operations are needed to complete single-point detection, and when multiple marking points are detected, the operation process can be repeated to complete the detection efficiently, which significantly shortens the measurement time and improves the detection efficiency, at the same time, the length of the flexible ruler can be flexibly adjusted according to the measured part, which adapts to the lower limb measurement needs of patients with different body types, has a wide range of applications, and to a certain extent, avoids the inconsistency of measurement caused by the difference in manual operation, not only reduces the working strength of the detection personnel, but also ensures the uniformity of the measurement result under different detection scenes and different detection personnel operations. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 It is a whole structure perspective view of the present application; Figure 2 It is a first perspective view of the internal structure of the main body of the present application; Figure 3 It is a second perspective view of the internal structure of the main body of the present application; Figure 4 It is a whole structure perspective view of the flexible ruler and the clamping assembly of the present application; Figure 5 It is a disassembled structure perspective view of the clamping assembly of the present application; Figure 6 It is a whole structure perspective view of the flexible ruler and the friction assembly of the present application; Figure 7 It is a disassembled structure perspective view of the friction assembly of the present application.
[0016] In the figure: 1, main body of the device; 2, flexible ruler; 3, winding assembly; 31, rotating rod; 41, pressure block; 42, V-shaped groove; 43, limiting rod; 431, clamping block; 44, moving block; 45, clamping plate; 46, insertion rod; 51, first tapered; 52, second tapered block; 521, compression spring; 53, inclined block; 54, resistance block; 541, L-shaped extrusion rod; 55, limiting block; 56, rack; 57, arc block; 6, displacement sensor. DETAILED DESCRIPTION
[0017] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.
[0018] The embodiments of the present application will be described below according to the overall structure of the present application.
[0019] A lower limb lymphedema high adaptability detection device, as shown in Figure 1 - Figure 7 The device body 1 is provided with a soft ruler 2 installed on the inner wall and extending to the outside, one end of the soft ruler 2 is fixedly connected to the outer wall of the device body 1, the other end of the soft ruler 2 is located in the inside of the device body 1 and is fixedly connected with a winding assembly 3, the winding assembly 3 comprises a clock spring fixedly connected to one end of the soft ruler 2, and the end of the clock spring is fixedly connected with a rotating rod 31, the patient's leg circumference can be detected by winding the soft ruler 2 on the part to be measured of the lower limb of the patient and then winding the soft ruler 2 by the winding assembly 3, a clamping assembly for limiting the soft ruler 2 is arranged on one side of the winding assembly 3, and a friction assembly for slowing down the winding speed of the soft ruler 2 is arranged on the other side of the winding assembly 3.
[0020] As shown in Figures 2-5 The clamping assembly comprises a pressing block 41 slidably connected to the surface of the device body 1, the top end of the pressing block 41 extends to the outer wall of the device body 1, a first spring is fixedly sleeved on the top end of the pressing block 41, and the top end of the first spring is fixedly connected to the top end of the inner wall of the device body 1, the elastic force of the first spring can drive the pressing block 41 to reset, a moving block 44 is attached to one side of the pressing block 41, the moving block 44 is slidably connected to the inner wall of the device body 1, and inclined surfaces are arranged at the positions where the pressing block 41 and the moving block 44 are in contact, so that the vertical force of the pressing block 41 can be converted into parallel force under the action of the inclined surfaces when the pressing block 41 moves downward, thereby facilitating the displacement of the moving block 44 by the pressing block 41.
[0021] As shown in Figure 5 The surface of the side of the pressing block 41 away from the moving block 44 is provided with a V-shaped groove 42, the movement range path of the clamping block 431 can be limited by the V-shaped groove 42, a V-shaped block is fixedly connected to the inner wall of the V-shaped groove 42 at the center position, a limiting rod 43 is rotatably connected to the bottom end of the inner wall of the device body 1, the top end of the limiting rod 43 is fixedly connected with a clamping block 431, and the clamping block 431 is clamped to the inner wall of the V-shaped groove 42, so that the pressing block 41 can be limited by the limiting rod 43 and the clamping block 431 through the V-shaped block.
[0022] As shown in Figure 4 and Figure 5It can be known that the two groups of clamping plates 45 are arranged on the side surface of the moving block 44 away from the pressing block 41, the soft ruler 2 is inserted between the two groups of clamping plates 45, and the length of the soft ruler 2 is fixed by moving one group of clamping plates 45 and cooperating with the other group of clamping plates 45. A plurality of insertion rods 46 are fixedly connected to one side surface of one group of clamping plates 45, a second spring is sleeved on the outer wall of the insertion rod 46, the second spring is fixedly connected with the moving block 44, a insertion slot matched with the insertion rod 46 is arranged on one side surface of the moving block 44, when one group of clamping plates 45 is pressed by the moving block 44, the insertion rod 46 is inserted into the inner wall of the insertion slot, at this time, the second spring is pressed, and then the length of the soft ruler 2 can be fixed, when the pressing block 41 resets and the pushing force on the moving block 44 is cancelled, the moving block 44 and one group of clamping plates 45 can reset under the elastic action of the second spring.
[0023] Referring to Figure 7 It can be known that the friction assembly comprises a resisting block 54 slidably connected to the surface of the device body 1, the bottom end of the resisting block 54 is attached with an inclined block 53, the inclined block 53 is slidably connected to the inner wall of the device body 1, and the contacting positions of the resisting block 54 and the inclined block 53 are all provided with inclined surfaces. When the resisting block 54 moves downward, the vertical downward force of the resisting block 54 can be converted into a force for driving the parallel movement of the inclined block 53 under the action of the inclined surfaces.
[0024] Referring to Figure 2 , Figure 3 , Figure 6 , Figure 7 It can be known that the top end of the winding assembly 3 is fixedly connected with a first taper 51, one side of the first taper 51 is provided with a second taper block 52, when the overlapping area of the first taper block 51 and the second taper block 52 is larger, the resistance of the winding assembly 3 is larger, the speed of the test paper is slower, the surface of the inclined block 53 is provided with a sliding groove, the outer wall of the second taper block 52 is fixedly connected with a connecting rod extending to the inner wall of the sliding groove, and the bottom end of the connecting rod is fixedly connected with a compression spring 521, the bottom end of the compression spring 521 is fixedly connected to the bottom end of the inner wall of the sliding groove, and the compression spring 521 can drive the second taper block 52 to reset.
[0025] Referring to Figure 6 and Figure 7 It can be known that the upper surface of the resisting block 54 is fixedly sleeved with an L-shaped extrusion rod 541, one end of the L-shaped extrusion rod 541 is in contact with the upper surface of the second taper block 52, through the arrangement of the L-shaped extrusion rod 541, when the resisting block 54 moves downward, the L-shaped extrusion rod 541 can drive the second taper block 52 to move downward through the L-shaped extrusion rod 541. The top end of the resisting block 54 extends to the outer wall of the device body 1, the outer wall of the resisting block 54 is fixedly sleeved with a third spring at an upper position, and the third spring is fixedly connected with the top end of the inner wall of the device body 1. The elastic force of the third spring can drive the resisting block 54 to reset.
[0026] Referring to Figure 6 and Figure 7It can be known that the inner wall of the device body 1 is connected with the rack 56 through the torsion spring, the top end of the rack 56 is fixedly connected with the arc-shaped block 57 extending to the outer wall of the device body 1, the side surface of the abutting block 54 close to the rack 56 is connected with the limiting block 55 through the torsion spring, the limiting block 55 is engaged with the rack 56, the position of the abutting block 54 can be limited through the mutual cooperation of the limiting block 55 and the rack 56, when the abutting block 54 needs to be reset, the arc-shaped block 57 is pressed, the arc-shaped block 57 drives the rack 56 to rotate, the rack 56 is separated from the limiting block 55, and the limiting of the limiting block 55 and the rack 56 can be cancelled.
[0027] Referring to Figure 1 and Figure 4 It can be known that the inner wall of the device body 1 is connected with the rack 56 through the torsion spring, the top end of the rack 56 is fixedly connected with the arc-shaped block 57 extending to the outer wall of the device body 1, the side surface of the abutting block 54 close to the rack 56 is connected with the limiting block 55 through the torsion spring, the limiting block 55 is engaged with the rack 56, the position of the abutting block 54 can be limited through the mutual cooperation of the limiting block 55 and the rack 56, when the abutting block 54 needs to be reset, the arc-shaped block 57 is pressed, the arc-shaped block 57 drives the rack 56 to rotate, the rack 56 is separated from the limiting block 55, and the limiting of the limiting block 55 and the rack 56 can be cancelled.
[0028] The working principle of the present application is as follows: when it is necessary to detect the leg circumference of a patient, first, mark 1 cm above the most protruding part of the patient's medial malleolus, 10 cm below the lower edge of the patella (below the knee), and 15 cm above the upper edge of the patella (above the knee), then pull out the flexible ruler 2 from the inside of the device body 1, apply axial pressure to the pressing block 41, the pressing block 41 moves downward along the axial direction of the device body 1 under the action of the pressure, and then extrudes the first spring to cause elastic deformation, at this time, the clamping block 431 on the limiting rod 43 moves from the bottom end of the V-shaped groove 42 to the top end of one side, after the pressure on the pressing block 41 is cancelled, the clamping block 431 is clamped to the top end center position of the V-shaped block on the inner wall of the V-shaped groove 42, under the action of the inclined surface of the moving block 44 and the pressing block 41, the moving block 44 moves to one side under the pushing of the pressing block 41, at this time, the insertion rod 46 is inserted into the preset insertion groove in the inner wall of the moving block 44, and the second spring is extruded, the moving block 44 pushes a group of clamping plates 45 to move close to another group of fixedly arranged clamping plates 45 through transmission, and the flexible ruler 2 is clamped and fixed. Then, the soft ruler 2 with a pre-stretched length is set on the part of the patient's lower limb to be measured, and the soft ruler 2 is adjusted to the pre-set mark. Then, axial pressure is applied to the abutting block 54, the abutting block 54 moves axially downward along the main body 1 of the device and extrudes the third spring to cause elastic deformation, and at the same time, the L-shaped extrusion rod 541 drives the second conical block 52 to move downward synchronously. At this time, the compression spring 521 is compressed and deformed under the pressure of the second conical block 52, and at the same time, the axial pressure of the abutting block 54 is converted into the horizontal lateral force of the inclined block 53 by the inclined surface transmission of the inclined block 53 and the abutting block 54, which drives the second conical block 52 to translate to the first conical block 51 while moving downward, ensuring that the second conical block 52 is always in close contact with the outer surface of the first conical block 51 during movement, increasing the frictional resistance of the first conical block 51 when rotating. By cooperating with the rotating rod 31 and the clockwork spring, the speed of winding the soft ruler 2 is slowed down, so as to fine-tune the fitting position of the soft ruler 2 during the contraction process, and ensure that the soft ruler 2 is in close contact with the marked position of the patient's leg. After the position of the soft ruler 2 is adjusted, axial pressure is applied to the pressing block 41 again, so that the clamping block 431 slides to the other end of the V-shaped groove 42. Then, the pressure applied to the pressing block 41 is removed, and the pressing block 41 moves upward along the axis under the elastic restoring force of the first spring to reset. At this time, the clamping block 431 is reset to the bottom end of the V-shaped groove 42, realizing the axial positioning of the pressing block 41. After the pressing block 41 is reset, the pushing force on the moving block 44 is removed, and a set of clamping plates 45 move reversely and reset under the elastic restoring force of the second spring, releasing the clamping and fixing state of the soft ruler 2. At this time, the soft ruler 2 is pre-set in the rotating rod 31 inside the main body 1 of the device, and the clockwork spring is activated under the elastic restoring force. When the soft ruler 2 is in close contact with the marked position of the patient's leg and reaches the pre-set fitting pressure, the extension length data of the soft ruler 2 is collected by the displacement sensor 6 built-in the main body 1 of the device, and after being converted by the data processing module, the actual measurement length of the soft ruler 2 is displayed in real time on the display screen provided on the surface of the main body 1 of the device, completing the leg circumference detection of a single marked point. When another marked point of the patient needs to be detected, the arc-shaped block 57 is rotated by being pulled, driving the rack 56 to rotate synchronously, canceling the limitation of the rack 56 on the limiting block 55. At this time, the abutting block 54 is reset under the elastic restoring force of the third spring, the second conical block 52 is separated from the first conical block 51, and the soft ruler 2 is restored to a free moving state. The soft ruler 2 is pulled out from the main body 1 of the device to a pre-set length, and the above detection operation process is repeated, so as to complete the leg circumference detection of another marked point. When the pre-set marked point detection is completed, the whole process of measuring the leg circumference of the patient's lower limb is completed, and manual measurement by the detection personnel is not needed, effectively avoiding the measurement error caused by the difference in manual operation, and significantly improving the accuracy and reliability of the detection result. The contents not described in detail in the present description belong to the existing technology known to those skilled in the art.
[0029] Although the embodiments of the present application have been shown and described, the present embodiments are merely illustrative of the present application, and are not intended to limit the present application, and the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner, and those skilled in the art can make modifications, replacements and variations of the embodiments without creative contribution after reading the present specification, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.
Claims
1. A lower extremity lymphedema high adaptability detection device, comprising a device main body (1), characterized in that: The device body (1) inner wall is provided with a soft ruler (2) extending to its outside, one end of the soft ruler (2) is fixedly connected with the device body (1) outer wall, the other end of the soft ruler (2) is located in the device body (1) inside, and a winding assembly (3) is fixedly connected, the winding assembly (3) includes a clock spring fixedly connected with one end of the soft ruler (2), and the end of the clock spring is fixedly connected with a rotating rod (31), one side of the winding assembly (3) is provided with a clamping assembly for limiting the soft ruler (2), and the other side of the winding assembly (3) is provided with a friction assembly for slowing down the winding speed of the soft ruler (2).
2. The highly adaptable detection device for lower extremity lymphedema according to claim 1, wherein: The clamping assembly includes a pressing block (41) slidingly connected to the surface of the device body (1), the top end of the pressing block (41) extends to the outer wall of the device body (1), a first spring is fixedly sleeved at the top end of the pressing block (41), and the top end of the first spring is fixedly connected to the top end of the inner wall of the device body (1), a moving block (44) is attached to one side of the pressing block (41), the moving block (44) is slidingly connected to the inner wall of the device body (1), and the pressing block (41) and the moving block (44) are provided with inclined surfaces at the contact positions.
3. The highly adaptable detection device for lower extremity lymphedema according to claim 2, characterized in that: A V-shaped groove (42) is formed on one side surface of the pressing block (41) away from the moving block (44), a V-shaped block is fixedly connected to the inner wall of the V-shaped groove (42), a limiting rod (43) is rotatably connected to the bottom end of the inner wall of the device body (1), a clamping block (431) is fixedly connected to the top end of the limiting rod (43), and the clamping block (431) is clamped to the inner wall of the V-shaped groove (42).
4. The highly adaptable detection device for lower extremity lymphedema according to claim 3, characterized in that: Two groups of clamping plates (45) are arranged on one side surface of the moving block (44) away from the pressing block (41), the soft ruler (2) penetrates between the two groups of clamping plates (45), a plurality of insertion rods (46) are fixedly connected to one side surface of one group of clamping plates (45), a second spring is sleeved on the outer wall of the insertion rod (46), and the second spring is fixedly connected with the moving block (44), and an insertion groove matched with the insertion rod (46) is formed on one side surface of the moving block (44).
5. The highly adaptable detection device for lower extremity lymphedema according to claim 1, wherein: The friction assembly includes a resisting block (54) slidingly connected to the surface of the device body (1), an inclined block (53) is attached to the bottom end of the resisting block (54), the inclined block (53) is slidingly connected to the inner wall of the device body (1), and the resisting block (54) and the inclined block (53) are provided with inclined surfaces at the contact positions.
6. The highly adaptable detection device for lower extremity lymphedema according to claim 5, wherein: A first taper (51) is fixedly connected to the top end of the winding assembly (3), a second taper block (52) is arranged on one side of the first taper (51), a sliding groove is formed on the surface of the inclined block (53), a connecting rod extending to the inner wall of the sliding groove is fixedly connected to the outer wall of the second taper block (52), a compression spring (521) is fixedly connected to the bottom end of the connecting rod, and the bottom end of the compression spring (521) is fixedly connected to the bottom end of the inner wall of the sliding groove.
7. The highly adaptable detection device for lower extremity lymphedema according to claim 6, wherein: The upper surface of the resisting block (54) is fixedly sleeved with an L-shaped extruding rod (541), one end of the L-shaped extruding rod (541) is in contact with the upper surface of the second conical block (52), the top end of the resisting block (54) extends to the outer wall of the device body (1), a third spring is fixedly sleeved at the position close to the upper surface of the outer wall of the resisting block (54), and the third spring is fixedly connected with the top end of the inner wall of the device body (1).
8. The highly adaptable detection device for lower extremity lymphedema according to claim 7, characterized in that: The inner wall of the device body (1) is connected with a rack (56) through a torsion spring, the top end of the rack (56) is fixedly connected with an arc-shaped block (57) extending to the outer wall of the device body (1), the surface of the side of the resisting block (54) close to the rack (56) is connected with a limiting block (55) through a torsion spring, and the limiting block (55) is engaged with the rack (56).
9. The highly adaptable detection device for lower extremity lymphedema according to claim 7, wherein: The inner wall of the device body (1) is provided with a displacement sensor (6) attached to the surface of the flexible ruler (2) on one side of the two groups of clamping plates (45), the device body (1) is internally provided with a circuit board and a data processing module, and the upper surface of the device body (1) is provided with a display screen.