Neck shielded brain pet device and method

Abstract

Neck shielding brain PET device, including support seat (1), PET device (2), shielding device (3). The support seat includes a base (11), a support frame group (12), and a back plate (13); the PET device (2) is installed outside the back plate, and the shielding device is located outside the device; the shielding device includes a fixed shielding group (31) and an adjustable shielding group (32); the fixed shielding group includes a plurality of fixed shielding plates (311) and fastening members (312); the adjustable shielding group includes a shielding support frame group (321), a horizontal guide rail group (322), a fixed buckle group (323), a short guide rail group (324), a left plate (325), and a right plate (326); the fixed buckle group includes four fixed buckles (3231). A detection method is also included, which comprises a preparation step, an adjustment shielding step, a detection step, and a replacement detection or end step.

Description

Technical Field

[0001] This invention relates to the technical field of improved applications of PET equipment, specifically a neck-shielded brain PET device and method. Background Technology

[0002] PET technology is one of the most important clinical medical imaging technologies, and it is widely used in the detection of humans and medical animals.

[0003] Currently, for a given PET scanner, its field of view is relatively fixed, roughly a regular N-prism (or roughly considered a cylinder). For example, the field of view enclosed by ten detection faces is a regular deca-prism, and that enclosed by twelve detection faces is a regular dodecagonal prism. This laterally positioned regular N-prism region is generally considered to have its front-to-back depth as the axial field of view and its vertical height difference as the radial field of view. (See instruction manual) Figure 1 As shown.

[0004] For PET equipment, there are two common scenarios for routine scanning: one is... Figure 2 As shown, this occurs when the scanned object is small and completely within the scanning field of view. In this case, upward or downward gamma rays can be received, while gamma rays to the sides are largely unreceived. However, the received gamma rays are sufficient to obtain a clear image.

[0005] Another scenario is when the device size remains essentially constant. This is used to scan larger, longer objects, because a full-body scan is usually not necessary; only specific areas, such as the brain or abdomen, are needed. In this case, smaller objects are scanned (see [link to original text]). Figure 2 The device shown in the left image can still be used. However, this presents a disadvantage. Because without obstruction / blocking, some gamma rays will be emitted from the body outside the scanning field of view (see...). Figure 2 (Right image). PET detects gamma photon pairs. According to the algorithm of the PET device, after this part of the radiation is received, the main error comes from the detection of a photon from a gamma photon pair outside the field of view and a photon from a gamma photon pair inside / outside the field of view. These photons are mistakenly identified as photons emitted by the annihilation of a positron. Including these photon pairs, which should not be considered in the calculation, will significantly reduce the imaging quality of the PET image.

[0006] Given the inability to eliminate out-of-field radiation during calculations, it is necessary to exclude unwanted radiation, ideally preventing it from being included during scanning. Currently, there is a lack of specific solutions in existing technologies. Existing shielding devices are relatively simple, such as CN104414671A, where the shielding element is merely a ring-shaped structure at the outer edge. "The shielding element 1 of this invention is generally a ring-shaped structure, including: a main body made of cast lead 101, and a support portion made of an aluminum ring (ring portion) 102 and an aluminum plate (plate portion) 103," located at the outer edge of the detection section. CN208243567U also includes an edge-mounted annular baffle, "and also provides two sets of shielding baffles 500, which are ring-shaped structures located at the inner ring of the mounting backplate, covering the crystal arrangement of the detector module." Based on the problems raised in this application, the shielding effect of existing technologies is limited, making it difficult to significantly improve image quality. Summary of the Invention

[0007] The purpose of this invention is to provide a PET device with a comprehensive and appropriate shielding method, so that rays outside the scanning field of view that are not needed for scanning are essentially shielded, thereby maximizing image quality. This is achieved by using a combination of fixed and adjustable shielding. The main improvement of this application compared to existing technologies is that the lead plate of the fixed shield extends vertically, resulting in better basic shielding, whereas existing technologies do not; their basic shielding plate extends radially (laterally) across the PET, as seen in CN104414671A. Figure 5 and CN208243567U Figure 6 Furthermore, the adjustable shielding gate described in this application is not inspired by existing technologies and was independently developed and proposed in this application. It is primarily designed for detecting the brain below the neck in experimental subjects (mainly laboratory animals), achieving good detection results.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a neck shielding brain PET device, characterized in that it includes a support base 1, a PET device 2, and a shielding device 3.

[0009] The support includes a base 11, a support frame 12, and a back plate 13.

[0010] The PET unit 2 is installed on the outside of the back panel, and the shielding device is located on the outside of the PET unit.

[0011] The shielding device includes a fixed shielding group 31 and an adjustable shielding group 32. The fixed shielding group is installed on both sides of the detection chamber of the PET device, and the adjustable shielding group is installed vertically on one side of the detection bed. The fixed shielding assembly includes a plurality of fixed shielding plates 311 and a plurality of fastening elements 312; the plurality of fixed shielding plates are fixed to both sides of the detection cavity of the PET device by the plurality of fastening elements, each forming a vertical ring.

[0012] The adjustable shielding assembly includes a shielding bracket assembly 321, a transverse guide rail assembly 322, a fixing buckle assembly 323, a short guide rail assembly 324, a left plate 325, and a right plate 326. The left bracket 3211 and right bracket 3212 of the shielding bracket assembly are fixed to both sides of the base and stand upright. The upper guide rail 3221 and lower guide rail 3222 of the transverse guide rail assembly are horizontally fixed to the upper and lower sides of the shielding bracket assembly, respectively. Each of the left and right plates has an inward-facing semi-circular or semi-elliptical groove.

[0013] The fixing buckle assembly includes four fixing buckles 3231. Two upper fixing buckles are electrically and slidably mounted on the upper guide rail, and two lower fixing buckles are electrically and slidably mounted on the lower guide rail. Each of the four fixing buckles is equipped with a short guide rail. The left plate is electrically and slidably mounted on the two short guide rails on the left side, and the right plate is electrically and slidably mounted on the two short guide rails on the right side.

[0014] The neck shielding PET device described above is characterized in that it further comprises a plurality of L-shaped fixing strips, which are fixedly connected between the shielding support assembly and the back plate.

[0015] It also has a testing bed assembly 4, which includes a bed body 41, a fixed end 42 and a sliding bed base 43. One end of the bed body is fixed to the fixed end, and the fixed end is slidably fixed to the sliding bed base.

[0016] The first electrical control device controls the left and right movement of the four fixed buckles. The second electrical control device controls the forward and backward movement of the left and right panels. The third electrical control device controls the forward and backward movement of the bed frame.

[0017] A neck shielded brain PET detection method, which is implemented using the neck shielded brain PET device as described above, is characterized by including the following steps: (1) Preparation step: Place the test subject on the bed and fix it, power on the PET device for self-test, confirm that the control movement of the first, second and third electrical control devices is normal, and move the left plate and right plate to the outside.

[0018] (2) Adjusting the shielding procedure: Move the bed into the detection chamber of the PET device until it reaches the detection position, confirm the position of the neck of the object being detected, and adjust the front and rear positions of the left and right plates through the second electronic control device to align them with the neck position. Then, control the left and right plates to move horizontally inward through the first electronic control device until they clamp the neck.

[0019] (3) Detection steps: Start the PET device, perform PET scanning, collect detection data, calculate and form detection images.

[0020] (4) Change or end the test: If the test task is completed, then end the test. If there are still untested objects, then do the following: move both the left and right plates to the outside, move the bed outward, change the test object, return to step 2, and continue the test.

[0021] The neck-shielded PET scan method described above is characterized in that: in step 1, the subject to be scanned is placed on the bed and fixed, specifically by using two clamps to fix the subject to be scanned at a predetermined position on the bed.

[0022] The alignment with the neck position mentioned in step 2 means that each groove is aligned with the neck position. The clamping of the neck mentioned in step 2 means that the neck is clamped after each groove is closed.

[0023] Compared to existing technologies, this application has several non-obvious advantages: First, existing technologies lack such a targeted shielding device. Existing technologies only involve setting a static shielding ring / ring within the PET detection cavity, which is noticeably less effective than the airtight shielding setup of this application. Second, the implementation method of this application for the fixed shielding portion is significantly superior to existing technologies, such as CN104414671A. While CN104414671A has an outer shielding ring, this ring itself is coaxial with the detection cavity and extends both internally and externally. The base shielding plate extends radially (laterally) along the PET. (See CN104414671A). Figure 5 and CN208243567U Figure 6 Furthermore, the fixed shielding in this application extends perpendicular to the axis of the detection cavity, resulting in better shielding performance from the fixed shielding section. This aspect is not found in existing technologies. Third, to achieve better shielding, this application specifically improves the shielding method. Combined with the adjustable shielding section, it effectively shields most signals from the body, eliminating interference with the acquired signal at the source. Existing technologies do not offer such a suitable shielding method. Fourth, the adjustable shielding section of this application has a stable and adjustable structure, achieving a minimalist fixing method while also allowing for front-to-back and left-to-right adjustment, meeting the needs of detection objects of different lengths and sizes. This is also not found in existing technologies. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the two-way field of view of a typical PET device.

[0025] Figure 2 This is a schematic diagram illustrating the principle of image quality degradation for longer detection objects.

[0026] Figure 3This is a front view of the device of this application at a 45-degree angle.

[0027] Figure 4 This is a side view of the device in this application.

[0028] Figure 5 This is a schematic diagram of the device of this application at a 70-degree angle.

[0029] Figure 6 This is a photograph of the device in this application without any objects being tested.

[0030] Figure 7 The image shows a photograph of the object being tested for the device in this application.

[0031] Figure 8 This is a schematic diagram illustrating the four coincidence events in actual PET testing.

[0032] Reference numerals: 91. Axial field of view; 92. Radial field of view; 93. Smaller object to be tested; 94. Larger object to be tested; Support 1; PET device 2; Shielding device 3; Base 11; Support assembly 12; Back plate 13; Fixed shielding assembly 31; Adjustable shielding assembly 32; Fixed shielding plate 311; Fastener 312; Shielding bracket assembly 321; Transverse guide rail assembly 322; Fixing buckle assembly 323; Short guide rail assembly 324; Left plate 325; Right plate 326; Left bracket 3211; Right bracket 3212; Upper guide rail 3221; Lower guide rail 3222; Fixing buckle 3231; L-shaped fixing strip 327; Detection bed assembly 4; Bed body 41; Fixed end 42; Sliding bed seat 43; 81. True coincidence event; 82. Scattered coincidence event; 83. Random coincidence event; 84. Multiple coincidence event. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. This application is groundbreaking in the shielding of external noise signals of general PET devices. Examples, such as specific numerical values ​​of device size, should not be considered as necessary limitations on this application.

[0034] Example 1

[0035] A neck-shielded brain PET device is characterized by comprising a support base 1, a PET device 2, and a shielding device 3. The shielding device of this application is a significantly separate structure compared to existing technologies, especially the adjustable portion, which is not disclosed or illustrated in existing technologies. Although the fixed shielding portion is similar in position to existing technologies, this application extends the shielding in a vertical plane, resulting in a significantly better effect. The adjustable portion is a separate device component, which facilitates installation and adjustment, and also allows for easy removal when not in use, for example, considering detection speed and ignoring the adverse effects on image quality, enabling more efficient detection.

[0036] The support includes a base 11, a support frame 12, and a back plate 13. The base is a large and heavy seat that can provide sufficient support. The support frame is reinforced with diagonal supports on the outside, so that the back plate is securely fixed to meet the fixing effect of the PET device.

[0037] The PET device 2 is mounted on the outside of the backplate, and the shielding device is located on the outside of the PET device. The PET device is fixed, and the stable backplate is the base for installation. Viewed from the side, the PET device can also be mounted at a position covering half the radial dimension on both the inner and outer sides of the backplate. The PET detector unit can be fixed to the required position on the backplate by various fixing bolts, fixing plates, or L-shaped fasteners. There can be multiple or more sets of fixing components of the same or similar shape along the circumference of the PET, such as various fixing bolts, fixing plates, or L-shaped fasteners, and the fixing method is, for example, bolt fastening.

[0038] The shielding device includes a fixed shielding group 31 and an adjustable shielding group 32. The fixed shielding group is installed on both sides of the detection cavity of the PET device, while the adjustable shielding group is installed vertically on one side of the detection bed. As the names suggest, it consists of fixed shielding and adjustable shielding. The shielding material here is, for example, lead plate, or other metallic materials capable of shielding gamma rays.

[0039] The fixed shielding assembly includes a plurality of fixed shielding plates 311 and a plurality of fastening elements 312. The plurality of fixed shielding plates are fixed to both sides of the detection cavity of the PET device by the plurality of fastening elements, each forming a vertical ring. The fixed shielding forms the first barrier, creating a vertical ring of a certain thickness from the outermost edge of the PET detection cavity, thus ensuring that at least a portion of the signal from the torso is not transmitted. This fixed shielding exists on both the inner and outer sides.

[0040] The adjustable shielding assembly includes a shielding bracket assembly 321, a transverse guide rail assembly 322, a fixing buckle assembly 323, a short guide rail assembly 324, a left plate 325, and a right plate 326. The left bracket 3211 and right bracket 3212 of the shielding bracket assembly are fixed to both sides of the base and stand upright. The upper guide rail 3221 and lower guide rail 3222 of the transverse guide rail assembly are horizontally fixed to the upper and lower sides of the shielding bracket assembly, respectively. Each of the left and right plates has an inward-facing semi-circular or semi-elliptical groove. This design allows both the left and right plates to move forward and backward, and left and right. Regardless of the specific length of the object being tested, these two pairs of semi-circular or semi-elliptical grooves can be tightened at the neck of the object, with virtually no gaps or very small gaps, to minimize the detection of radiation from the body.

[0041] The fixing buckle assembly includes four fixing buckles 3231. Two upper fixing buckles are electrically and slidably mounted on the upper guide rail, and two lower fixing buckles are electrically and slidably mounted on the lower guide rail. Each of the four fixing buckles is mounted on a short guide rail. The left plate is electrically and slidably mounted on the two left-side short guide rails, and the right plate is electrically and slidably mounted on the two right-side short guide rails. Generally, the four fixing buckles are symmetrically separated or closed on the upper and lower guide rails to open and close the left and right plates. The left and right plates on the four short guide rails slide synchronously back and forth to control their forward and backward positions, corresponding to the neck position of the object being detected.

[0042] The aforementioned neck-shielded brain PET device is characterized by further comprising a plurality of L-shaped fixing strips, which are fixedly connected between the shielding support assembly and the backplate. Considering that simply mounting the shielding support assembly on the base is not sufficiently stable, a plurality of L-shaped fixing strips are required. The fixing strips are typically connected to and fixed to the backplate.

[0043] It also includes a testing bed assembly 4, which comprises a bed body 41, a fixed end 42, and a sliding bed base 43. One end of the bed body is fixed to the fixed end, and the fixed end is slidably fixed to the sliding bed base. The portion of the bed body that extends into the testing cavity is generally made of a radiation-free material.

[0044] The first electronic control unit controls the left and right movement of the four fixed latches. The second electronic control unit controls the forward and backward movement of the left and right panels. The third electronic control unit controls the forward and backward movement of the bed frame. The electronic control units, drives, and receivers can be wired for cost savings, or, for enhanced safety, a battery-powered wireless connection can be used to avoid interference from complex wiring.

[0045] Example 2

[0046] A neck shielded brain PET detection method, which is implemented using the neck shielded brain PET device as described above, is characterized by including the following steps: (1) Preparation step: Place the test subject on the bed and fix it, power on the PET device for self-test, confirm that the control movement of the first, second and third electrical control devices is normal, and move the left plate and right plate to the outside.

[0047] At this point, there's a standard for moving the left and right panels to the outside, for example, leaving a gap of at least 30-50cm in the middle to ensure that the head of the object being tested can enter the PET detection chamber. This is secured, for example, by using clamping openings (facing upwards) on both sides of the bed. After placing the object, use the clamps from both sides to secure it and prevent it from falling off.

[0048] (2) Adjusting the shielding procedure: Move the bed into the detection chamber of the PET device until it reaches the detection position. Confirm the position of the neck of the object being detected. Adjust the front and rear positions of the left and right plates using the second electronic control device to align them with the neck position. Then, control the left and right plates to move horizontally inward using the first electronic control device until they clamp the neck. This clamping of the neck may involve leaving a gap of about 1 cm or 2-5 cm, for example.

[0049] (3) Detection steps: Start the PET device, perform PET scanning, collect detection data, calculate and form detection images. Perform detection after confirming the location of the object to be detected, and acquire data normally.

[0050] When necessary, a comparison can be made between shielding and not shielding. Through comparison, the shielding device of this application can very effectively improve image quality.

[0051] (4) Change or end the test: If the test task is completed, then end the test. If there are still untested objects, then do the following: move both the left and right plates to the outside, move the bed outward, change the test object, return to step 2, and continue the test.

[0052] In step 1, the object to be tested is placed on the bed and fixed in place, specifically by using two clamps to fix the object to be tested in the predetermined position on the bed.

[0053] Step 2, "aligning with the neck position," means that each groove is aligned with the neck position. Step 2, "clamping the neck," means that the grooves are closed and clamped to the neck. Optionally, the groove edges may have a resin or rubber cushioning layer. Furthermore, to ensure the closed grooves are indeed small, the left and right plates can be staggered, allowing for overlap and forming a smaller closing hole.

[0054] Example 3

[0055] The basic implementation method of this embodiment is the same as that of Embodiment 1. The difference is that, in order to enhance the fixing strength of the shielding bracket assembly, instead of directly mounting the two horizontal guide rail assemblies on the vertical left and right supports, the upper and lower supports are first installed so that the shielding bracket assembly itself forms an "U"-shaped structure, which enhances the structural stability. Then, the two horizontal guide rail assemblies are respectively installed on the upper and lower supports. Other settings and operation methods are the same as in Embodiment 1.

[0056] Example 4

[0057] This embodiment is basically the same as embodiment 2, except that the inward semi-circular or semi-elliptical groove on the left and right plates is replaced with a curved groove adapted to the object being detected, which is more suitable for monkeys or other animals. The edge shape of the groove can be a Bayesian curve or other curves, or a combination of multiple curves.

[0058] Example 5

[0059] The principles of this application will be explained below with reference to the accompanying drawings. As you can see, Figure 1 The image shows an overall view of the PET device according to this application. Rotation is required here; that is, the frame securing the entire device is designed to allow for overall rotation. For fixing the backplate, those skilled in the art can use common methods. The lateral and longitudinal fields of view of the detection cavity are clearly visible.

[0060] Figure 2 The image shows the scanning process for objects of different sizes. It can be seen that for larger objects, when only the head is scanned without shielding, radiation from the body parts is unavoidable. This inevitably leads to insufficient image clarity because some rays that should not be included are also received by the detector.

[0061] Figure 3 The middle view is a 45-degree oblique view of this application, which clearly shows the basic structure of the support base 1, the PET device 2, and the adjustable shielding assembly 32. The fixed shielding assembly is obscured and is shown in other figures. It can be seen that the left and right plates are closed together and partially overlapped, forming a hole that can accommodate the neck, which represents the preferred effect of this application.

[0062] Figure 4A side view of this application is shown, which more clearly shows the positional relationships of the application. The support frame is at the innermost side, followed by the PET device, and the shielding device is on the outer side. The fixed shielding part is blocked by the left bracket here, but the structure of the adjustable shielding device can be clearly seen. The short guide rail slides horizontally on the transverse guide rail, and the fixing buckle can slide on the short guide rail to adjust the left and right plates. Because the figure of this application does not show the detection cavity viewed from the reverse side, it can be seen that there is also a fixed shielding ring on that side, with the same form as the one on the side closer to the detection bed.

[0063] Figure 5 This is a 70-degree oblique angle view. In this view, the position and installation of the fixed shielding part can be seen more clearly. It can be seen how it works together with the adjustable shielding part. The two work together to provide gamma rays with complete external shielding.

[0064] Figure 6 and Figure 7 These are actual photographs of the device described in this application. Compared to the previous schematic diagrams, the bed section is shown more clearly, and the application method of this application can also be clearly seen, achieving a better shielding effect.

[0065] Figure 8 The paper supplements the schematic diagram of PET acquisition coincidence events. It can be seen that only true coincidence events are needed to generate images. However, in actual operation, the number of scattering, random and multiple coincidence events is very large. When the detection object is only the head and the torso cannot be separated, the latter three types of coincidence events are generated more often. Through the operation of this application, the latter three types of false coincidence events can be reduced very effectively, and the image quality can be greatly improved.

[0066] The PET device of this application is fixed, so reinforcement can be considered at various points in the device, and the resulting accessories are also within the scope of the inventive concept of this application.

[0067] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics of the solutions is not described in detail here. It will be apparent to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the present invention is defined by the appended claims rather than the foregoing description. Therefore, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A neck-shielded brain PET device, characterized in that: Includes support base (1), PET device (2), and shielding device (3); The support includes a base (11), a support frame (12), and a back plate (13); The PET unit (2) is installed on the outside of the backplate, and the shielding device is located on the outside of the PET unit; The shielding device includes a fixed shielding group (31) and an adjustable shielding group (32); the fixed shielding group is installed on both sides of the detection cavity of the PET device, and the adjustable shielding group is installed vertically on one side of the detection bed; The fixed shielding assembly includes a plurality of fixed shielding plates (311) and a plurality of fastening elements (312); the plurality of fixed shielding plates are fixed to both sides of the detection cavity of the PET device by the plurality of fastening elements, each forming a vertical ring; The adjustable shielding assembly includes a shielding bracket assembly (321), a transverse guide rail assembly (322), a fixing buckle assembly (323), a short guide rail assembly (324), a left plate (325), and a right plate (326). The left bracket (3211) and right bracket (3212) of the shielding bracket assembly are fixed on both sides of the base and stand upright. The upper guide rail (3221) and lower guide rail (3222) of the transverse guide rail assembly are fixed transversely on the upper and lower sides of the shielding bracket assembly. Each of the left and right plates has an inward semi-circular or semi-elliptical groove. The fixing buckle assembly includes four fixing buckles (3231). Two upper fixing buckles are electrically and slidably mounted on the upper guide rail, and two lower fixing buckles are electrically and slidably mounted on the lower guide rail. Each of the four fixing buckles is equipped with a short guide rail. The left plate is electrically and slidably mounted on the two short guide rails on the left side, and the right plate is electrically and slidably mounted on the two short guide rails on the right side.

2. The neck-shielded brain PET device as described in claim 1, characterized in that: It also has multiple L-shaped fixing strips, which are fixedly connected between the shielding bracket assembly and the back plate; It also has a testing bed assembly (4), which includes a bed body (41), a fixed end (42) and a sliding bed seat (43). One end of the bed body is fixed on the fixed end, and the fixed end is slidably fixed on the sliding bed seat. The first electronic control device is used to control the left and right movement of the four fixed buckles; the second electronic control device is used to control the forward and backward movement of the left and right plates. The third electrical control device is used to control the forward and backward movement of the bed.

3. A neck-shielded brain PET scan method, implemented using the neck-shielded brain PET device as described in claim 2, characterized in that, Includes the following steps: 1) Preparation steps: Place the object to be tested on the bed and fix it. Power on the PET device for self-testing to confirm that the control and movement of the first, second and third electrical control devices are normal. Move both the left and right plates to the outside. 2) Adjusting the shielding procedure: Move the bed into the detection chamber of the PET device until it reaches the detection position, confirm the position of the neck of the object being detected, and adjust the front and rear positions of the left and right plates through the second electronic control device to align them with the neck position; The left and right plates will be controlled by the first electronic control device to move horizontally inward until they clamp the neck. 3) Detection steps: Start the PET device, perform PET scanning, collect detection data, calculate and generate detection images; 4) Change or end the inspection step: If the inspection task is completed, then end. If there are still uninspected objects, then do the following: move both the left and right panels to the outside, pull the bed outward, change the inspection object, return to step 2, and continue the inspection.

4. The neck-shielded brain PET detection method as described in claim 3, characterized in that: In step 1, the object to be tested is placed on the bed and fixed in place, specifically by using two clamps to fix the object to be tested in the predetermined position on the bed. The alignment with the neck position mentioned in step 2 means that each groove is aligned with the neck position. The clamping of the neck mentioned in step 2 means that the neck is clamped after each groove is closed.

Images