Multi-point ultrasonic probe calibration tool

Abstract

The utility model relates to a multi-point ultrasonic probe calibration tool, which is used for calibrating an ultrasonic probe and comprises a calibration tool main body, the markers penetrate through the two sides of the calibration tool main body and play a role in calibration, the markers comprise a plurality of coarse markers distributed at equal intervals and a plurality of groups of fine markers located among the coarse markers, and the numbers of the fine markers in each group are different; the bracket connecting mechanism is connected with the ultrasonic probe and the calibration tool main body; the angle sensor is positioned in the bracket connecting mechanism and is used for feeding back an angle signal; and the rotating shaft penetrates through two sides of the calibration tool main body and is connected with the bracket connecting mechanism and the angle sensor, so that the transmission of a rotating angle is realized. Compared with the prior art, the calibration tool is clear in structure, easy to manufacture and use and rapid to disassemble and assemble, the rotation angle of the calibration tool body can be conveniently adjusted, and calibration can be completed without auxiliary equipment.

Description

Technical Field

[0001] The utility model relates to the technical field of medical equipment, in particular to a multi-point ultrasonic probe calibration tool. Background Art

[0002] In recent years, with the improvement of ultrasound instrument performance and the accumulation of doctors' experience, ultrasound-based puncture technology has become a very important diagnostic technology. In clinical practice, the ultrasound probe image and the ultrasound probe puncture holder can be used to guide the puncture needle into the patient's body for interventional treatment, and the calibration tool is required to calibrate the ultrasound probe before the operation.

[0003] Existing ultrasonic calibration tools usually use N-line templates, and the mold design and production are highly complex. Traditional calibration tools usually require external equipment such as optical or electromagnetic positioning tools to assist in calibration, which is complicated to operate and occupies surgical space. Therefore, it is necessary to develop an ultrasonic probe calibration tool with a clear structure, simple production, detachable, and no need for auxiliary equipment to complete calibration.

[0004] Patent publication number CN115886867A discloses a streamlined ultrasound probe calibration system and method, and designs a model registration tool, which has a sharp needle inserted at one end and a positioning sensor fixed at the other end. Through simple calibration, the model registration tool is transformed into a positioning pen. The calibration model coordinate system is established through the model registration tool without the need for an additional positioning sensor, so that the calibration of the ultrasound probe can be completed through a positioning sensor, reducing the calibration cost. A small and simple octagonal calibration model is designed. The model obtains multiple effective positioning points through one ultrasound imaging, and can obtain more calibration targets with fewer calibration times, thereby improving the efficiency of calibration. However, the ultrasound probe calibration system is improved for the model registration tool, and still requires a position sensor magnetic marker, which occupies a certain surgical space and is complicated to operate. Utility Model Content

[0005] The purpose of the utility model is to overcome the defects of the above-mentioned prior art and to provide a multi-point ultrasonic probe calibration tool with clear structure, simple manufacture and use, quick assembly and disassembly, easy adjustment of the rotation angle of the calibration tool body and the ability to complete the calibration without the assistance of auxiliary equipment.

[0006] The purpose of the utility model can be achieved through the following technical solutions:

[0007] A multi-point ultrasonic probe calibration tool, used for calibrating an ultrasonic probe, comprising:

[0008] Calibration tool body;

[0009] The markers passing through both sides of the calibration tool body and playing a calibration role include a plurality of coarse markers distributed at equal intervals and a plurality of groups of fine markers located between the coarse markers, each group of fine markers having a different number;

[0010] A bracket connecting mechanism connecting the ultrasonic probe and the calibration tool body;

[0011] An angle sensor located inside the bracket connection mechanism and used to feed back an angle signal;

[0012] The rotating shaft passes through both sides of the calibration tool body and is connected to the bracket connecting mechanism and the angle sensor to realize the transmission of the rotation angle.

[0013] Furthermore, one side of the calibration tool body is provided with a connecting through hole adapted to the rotating shaft, and the other side away from the angle sensor is provided with a grooved hole to lock the rotating shaft and the calibration tool body to achieve synchronous rotation of the rotating shaft and the calibration tool body.

[0014] Furthermore, the rotating shaft is cylindrical, and a plurality of protrusions matching the grooved holes are arranged around its middle, and a cross-shaped end face protrusion is arranged on its top.

[0015] Furthermore, the angle sensor comprises:

[0016] Square shell;

[0017] An inner core rotatably connected to the outer shell, wherein the surface of the inner core is a cross-shaped groove adapted to be connected with the end face protrusion at the top end of the rotating shaft;

[0018] A pin is located at the other end of the housing, and the pin is connected to the ultrasound imaging system to achieve data transmission.

[0019] Furthermore, the bracket connection mechanism has a rear connection block with a square groove and a rear through hole, the shell is embedded in the square groove, and the pin passes through the rear through hole.

[0020] Furthermore, the bracket connecting mechanism has a middle connecting block with a middle through hole, the rotating shaft passes through the middle through hole, the middle through hole is used to determine the relative position and connect the calibration tool body and the bracket connecting mechanism, and the middle connecting block is parallel to the rear side connecting block.

[0021] Furthermore, the bracket connection mechanism also includes a connecting beam, the upper part of which is connected to the ultrasonic probe without affecting the rotation of the calibration tool body, and the two ends of the lower part of the connecting beam are respectively connected to the rear connecting block and the middle connecting block.

[0022] Furthermore, a plurality of coarse circular through holes arranged equidistantly in the transverse direction are provided on both sides of the main body of the calibration tool, and a plurality of groups of fine circular through holes are distributed between the coarse circular through holes for the markers to pass through.

[0023] Furthermore, the marker includes a coarse marker for its calibration function and a fine marker for determining the sequence number of the coarse marker under ultrasound imaging;

[0024] The coarse markers pass through the coarse circular through holes and are arranged in a horizontally equidistant manner;

[0025] The thin marker passes through the thin circular through hole and is located between the thick markers.

[0026] Furthermore, one form of the marker is a metal wire, which can be a metal material with high hardness and density such as silver and stainless steel.

[0027] Furthermore, the number of each group of fine markers is different. When the number of fine markers in a group is greater than one, they are arranged vertically and perpendicular to the line connecting the coarse markers. The number of fine markers at each location should be different to distinguish the groups of fine markers, so as to facilitate the determination of the sequence number of the coarse marker on the ultrasound image.

[0028] Furthermore, the number of the thin markers is 1 to 8 groups, preferably 2 to 4 groups. The spacing between the markers, the spacing between the markers and the rotating shaft, and the number of the markers can be specified according to usage requirements.

[0029] Compared with the prior art, the utility model has the following technical effects:

[0030] The ultrasonic probe calibration tool provided by the utility model has a simple structure, ingenious design, quick assembly and disassembly, easy use, and a large angle adjustment range. The calibration tool body is equipped with a number of equally spaced coarse markers for calibrating the physical coordinates of the ultrasonic probe. At the same time, fine markers are arranged between the coarse markers. According to the number of fine markers, the serial number of the coarse marker can be determined, thereby facilitating the rapid confirmation of the position of the ultrasonic probe. By rotating the shaft, the calibration tool body is driven to rotate, so that the ultrasonic probe can collect marker images at different rotation angles for calibration; in addition, the cross-shaped end face protrusion on the top of the shaft is matched with the cross-shaped groove on the surface of the inner core of the angle sensor to realize the transmission of rotation angle data, which improves the efficiency and convenience of using the calibration tool to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of the structure of the ultrasonic probe calibration tool shown in Example 1;

[0032] Figure 2 is a schematic structural diagram of the rotating shaft of the ultrasonic probe calibration tool shown in Example 1;

[0033] Figure 3 is a schematic structural diagram of the angle sensor of the ultrasonic probe calibration tool shown in Example 1;

[0034] Figure 4 is a structural schematic diagram of the ultrasonic probe calibration tool support connection mechanism shown in Example 1;

[0035] Figure 5 The ultrasonic probe calibration tool shown in Example 1 Figure 1 Enlarged view of point A in the middle;

[0036] Figure 6 It is a structural schematic diagram of the ultrasonic probe calibration tool body and the marker shown in Example 1.

[0037] Description of the markings in the figure:

[0038] 100-calibration tool body, 101-grooved hole, 102-connecting through hole, 103-coarse circular through hole, 104-thin circular through hole;

[0039] 200-marker, 201-coarse marker, 202-fine marker;

[0040] 300-bracket connecting mechanism, 301-connecting crossbeam, 302-square groove, 303-rear through hole, 304-middle through hole, 305-rear connecting block, 306-middle connecting block;

[0041] 400-angle sensor, 401-housing, 402-core, 403-pin;

[0042] 500-rotating shaft, 501-bump, 502-end face bump. DETAILED DESCRIPTION

[0043] The utility model is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the utility model, and a detailed implementation method and a specific operation process are given, but the protection scope of the utility model is not limited to the following embodiments. In the following implementation methods or embodiments, if there is no special description of the functional components or structures, it means that they are all conventional components or conventional structures used in the field to achieve the corresponding functions.

[0044] It should be noted that in the description of the present invention, the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0045] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the following embodiments, the ultrasonic probe model is 75L38, purchased from Shenzhen Mindray Corporation; the ultrasonic imaging system model is DC-8, purchased from Shenzhen Mindray Corporation; the angle sensor is a 3362P potentiometer purchased from Xincheng Huachuang Electronics Co., Ltd., and the resistance value of the potentiometer is different according to the corresponding angle of rotation, and the resistance value and the angle have a corresponding relationship.

[0047] Example 1

[0048] like Figure 1 As shown, a multi-point ultrasonic probe calibration tool is connected to the ultrasonic probe, comprising:

[0049] Calibration tool body 100;

[0050] The markers 200 passing through both sides of the calibration tool body 100 and playing a calibration role include a plurality of coarse markers 201 distributed at equal intervals, and a plurality of groups of fine markers 202 located between the coarse markers 201, and each group of fine markers 202 has a different number;

[0051] A support connection mechanism 300 connecting the ultrasonic probe and the calibration tool body 100;

[0052] An angle sensor 400 located inside the bracket connection mechanism 300 and used to feed back an angle signal;

[0053] The rotating shaft 500 passes through both sides of the calibration tool body 100 and is connected to the bracket connection mechanism 300 and the angle sensor 400 to realize the transmission of the rotation angle.

[0054] In this embodiment, the calibration tool body 100 is square and hollow inside. A connecting through hole 102 adapted to the rotating shaft 500 is provided on one side of the calibration tool body 100, and a groove hole 101 is provided on the other side away from the angle sensor 400 to lock the rotating shaft 500 and the calibration tool body 100, so as to realize the synchronous rotation of the rotating shaft 500 and the calibration tool body 100.

[0055] In this embodiment, if Figure 2 As shown, the rotating shaft 500 is cylindrical, and four protrusions 501 adapted to the grooved hole 101 are arranged around its middle, and the four protrusions 501 are distributed at equal intervals, and a cross-shaped end face protrusion 502 is arranged on the top.

[0056] In this embodiment, if Figure 3 As shown, the angle sensor 400 includes:

[0057] A square housing 401;

[0058] An inner core 402 rotatably connected to the outer shell 401, wherein the surface of the inner core 402 is a cross-shaped groove adapted to be connected to the end face protrusion 502 at the top of the rotating shaft 500;

[0059] A pin 403 is located at the other end of the housing 401 and is connected to an ultrasonic imaging system to achieve data transmission.

[0060] In this embodiment, if Figure 4 and Figure 5 As shown, the bracket connection mechanism 300 has a rear connection block 305 with a square groove 302 and a rear through hole 303, the housing 401 is embedded in the square groove 302, and the pin 403 passes through the rear through hole 303. The bracket connection mechanism 300 has a middle connection block 306 with a middle through hole 304, the shaft 500 passes through the middle through hole 304, the middle through hole 304 is used to determine the relative position and connect the calibration tool body 100 and the bracket connection mechanism 300, the middle connection block 306 is parallel to the rear connection block 305, and the middle connection block 306 is located inside the calibration tool body 100. The support connection mechanism 300 further includes a connecting crossbeam 301, the upper portion of which is connected to the ultrasonic probe without affecting the rotation of the calibration tool body 100, and the two ends of the lower portion of the connecting crossbeam 301 are respectively connected to the rear connecting block 305 and the middle connecting block 306. A plurality of coarse circular through holes 103 are arranged equidistantly in the horizontal direction on both sides of the calibration tool body 100, and a plurality of groups of fine circular through holes 104 are distributed between the coarse circular through holes 103 for the marker 200 to pass through.

[0061] In this embodiment, if Figure 6 As shown, the marker 200 includes a coarse marker 201 for calibration, and a fine marker 202 for determining the serial number of the coarse marker 201 under ultrasound imaging, so as to prevent the serial number of the coarse marker 201 from being determined when all the coarse markers 201 are not displayed; the coarse markers 201 pass through the coarse circular through holes 103 and are arranged equidistantly in the horizontal direction; the fine markers 202 pass through the fine circular through holes 104 and are located between the coarse markers 201. The material of the marker 200 is stainless steel. There are 14 coarse markers 201, and the coarse marker 201 closest to the rotating shaft 500 is marked with serial number 1, and the serial numbers are marked sequentially to 14. There are 3 groups of fine markers 202, and the first group of fine markers 202 has 1, which is located in the middle of the second coarse marker 201 and the third coarse marker 201, and is on the same horizontal line as the coarse marker 201. The second group of thin markers 202 has two thin markers, located in the middle of the sixth and seventh thick markers 201, and the two thin markers 202 are on the same longitudinal line and are equidistant from the horizontal line where the thick markers 201 are located. The third group of thin markers 202 has three thin markers, located in the middle of the tenth and eleventh thick markers 201, and the three thin markers 202 are on the same longitudinal line and are arranged at equal distances.

[0062] The working principle of this ultrasonic probe calibration tool is:

[0063] The ultrasonic probe is connected through the bracket connecting mechanism 300, and the positions of the bracket connecting mechanism 300 and the ultrasonic probe remain unchanged. The calibration tool body 100 is rotated around the rotating shaft 500. Since the shell 401 of the angle sensor 400 is connected to the bracket connecting mechanism 300, the rotating shaft 500 is connected to the inner core 402 of the angle sensor 400, and the shell 401 and the inner core 402 have a relative rotation angle, the rotation angle data of the calibration tool body 100 can be transmitted to the angle sensor 400, so as to realize the transmission of the rotation angle data from the calibration tool body 100 to the rotating shaft 500 and then to the angle sensor 400. The pin 403 of the angle sensor 400 is connected to the ultrasonic imaging system. Therefore, the ultrasonic images of the calibration tool at different angles can be obtained, which improves the efficiency and convenience of using the calibration tool to a certain extent.

[0064] The serial number of the coarse marker 201 is determined by the number of the fine markers 202. Since the coarse markers 201 are equidistant, the distance between the coarse marker 201 and the rotating shaft 500 can be quickly obtained. Combined with the rotation angle data obtained by the angle sensor 400, the coordinates of the coarse marker 201 in different ultrasound images can be obtained, thereby quickly confirming the position of the ultrasound probe.

[0065] Ultrasound probe calibration is the process of determining the spatial transformation relationship between the ultrasound image and the ultrasound probe, which is mainly divided into the following three steps:

[0066] (1) Obtaining the physical coordinates of the coarse marker 201

[0067] Taking the rotating shaft 500 as the origin of the ultrasound probe coordinate system, since the interval between each coarse marker 201 is fixed and the distance between the coarse marker 201 closest to the rotating shaft 500 and the rotating shaft 500 is determined, the distance ρ between each coarse marker 201 and the rotating shaft 500 can be deduced. i By rotating the rotating shaft 500, the calibration tool body 100 rotates around the rotating shaft 500, and at the same time drives the marker 200 attached thereto to make the same movement. At the same time, the rotating shaft 500 will rotate by an angle θ i The coordinates of the coarse marker 201 at different rotation angles are transmitted to the angle sensor 400, that is, the physical coordinates (ρ i ,θ i ), the serial numbers of the coarse markers 201 and the rotating shaft 500 are determined from near to far in order of 1-14, and the subscript is determined accordingly. The fine markers 202 are located between the coarse markers 2 and 3, 6 and 7, and 10 and 11, respectively.

[0068] (2) Obtaining the pixel coordinates of the coarse marker 201

[0069] The collected ultrasound images are Gaussian filtered and binarized, and all connected domains are traversed using an adaptive threshold until all regions of interest (ROI) in each image are found. The centroid coordinates of each region are obtained and recorded as (u i , v i ), the coordinates of these points are the pixel coordinates of the coarse marker 201 on the ultrasound image. First, determine the serial numbers of the coarse markers 201 on the left and right of the fine marker 202, and then deduce the serial numbers of all the coarse markers 201 in the ultrasound image in sequence, so that they are consistent with the real object coordinates (ρ i ,θ i ) correspond one to one.

[0070] (3) Solving the calibration matrix

[0071] Assume that the coordinate set of the coarse marker 201 entity in the ultrasound probe coordinate system is A, and the set of pixel coordinate points of the coarse marker 201 in the ultrasound image coordinate system is B. The number of elements in the two sets A and B is the same and one-to-one corresponding. To find the relationship between the two point sets, the following formula can be used to model: B = R*A+T. The SVD method is used to solve the coordinate transformation matrix between the ultrasound image coordinate system and the ultrasound probe coordinate system, that is, the rotation matrix R and the transfer matrix T need to be solved. First, the center point μ of the A and B sets is calculated respectively. A , μ B Then, to calculate the optimal rotation matrix R, it is necessary to eliminate the influence of the transfer matrix T, so the point set is re-centered to generate new point sets A' and B'. Then the covariance matrix H between the new point sets is calculated, and then the matrices U, S, and V are calculated by the SVD method formula [U, S, V] = SVD (H), and then the formula R = V*U T The required rotation matrix R is calculated, and finally the formula T = -R*μ is used A +μ B The transfer matrix T is obtained. In this way, the transformation matrix is ​​calibrated, and the relationship between the coordinate set A of the coarse marker 201 entity and the pixel coordinate point set B of the coarse marker 201 in the ultrasound image coordinate system is obtained, and the probe calibration is completed.

[0072] It should be pointed out that the above disclosure is only the preferred embodiment of the utility model, which does not limit the patent scope of the utility model, but is only used to help explain the utility model. The preferred embodiment does not describe all the details in detail, nor does it limit the utility model to only a specific implementation method. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and describes these embodiments in detail in order to better explain the principles and practical applications of the utility model, so that technicians in the relevant technical field can understand and use the utility model well. All equivalent structures or equivalent process changes made according to the contents of the utility model specification and drawings, or directly or indirectly used in other related technical fields, are similarly included in the patent protection scope of the utility model.

Claims

1. A multi-point ultrasonic probe calibration tool, characterized in that: Used for calibration of ultrasound probes, including: Calibration tool body (100); The markers (200) passing through both sides of the calibration tool body (100) and playing a calibration role include a plurality of coarse markers (201) distributed at equal intervals, and a plurality of groups of fine markers (202) located between the coarse markers (201), each group of fine markers (202) having a different number of markers; A support connection mechanism (300) connecting the ultrasonic probe and the calibration tool body (100); An angle sensor (400) located inside the bracket connection mechanism (300) and used to feed back an angle signal; A rotating shaft (500) passes through both sides of the calibration tool body (100) and is connected to the bracket connection mechanism (300) and the angle sensor (400) to achieve the transmission of the rotation angle.

2. A multi-point ultrasonic probe calibration tool according to claim 1, characterized in that: One side of the calibration tool body (100) is provided with a connecting through hole (102) adapted to the rotating shaft (500), and the other side away from the angle sensor (400) is provided with a grooved hole (101) to lock the rotating shaft (500) and the calibration tool body (100), thereby achieving synchronous rotation of the rotating shaft (500) and the calibration tool body (100).

3. A multi-point ultrasonic probe calibration tool according to claim 2, characterized in that: The rotating shaft (500) is cylindrical, with a plurality of protrusions (501) adapted to the grooved hole (101) arranged around its middle, and a cross-shaped end face protrusion (502) arranged on its top.

4. A multi-point ultrasonic probe calibration tool according to claim 3, characterized in that: The angle sensor (400) comprises: A square housing (401); An inner core (402) rotatably connected to the outer shell (401), the surface of the inner core (402) being a cross-shaped groove adapted to be connected to the end face protrusion (502) at the top end of the rotating shaft (500); A pin (403) is located at the other end of the housing (401), and the pin (403) is connected to an ultrasonic imaging system to achieve data transmission.

5. A multi-point ultrasonic probe calibration tool according to claim 4, characterized in that: The bracket connection mechanism (300) has a rear connection block (305) with a square groove (302) and a rear through hole (303), the housing (401) is embedded in the square groove (302), and the pin (403) passes through the rear through hole (303).

6. A multi-point ultrasonic probe calibration tool according to claim 5, characterized in that: The support connection mechanism (300) has a middle connection block (306) with a middle through hole (304), the rotating shaft (500) passes through the middle through hole (304) to connect the calibration tool body (100) and the support connection mechanism (300), and the middle connection block (306) is parallel to the rear side connection block (305).

7. A multi-point ultrasonic probe calibration tool according to claim 6, characterized in that: The support connection mechanism (300) further comprises a connecting crossbeam (301), the upper portion of which is connected to the ultrasonic probe without affecting the rotation of the calibration tool body (100), and the two ends of the lower portion of the connecting crossbeam (301) are respectively connected to the rear connecting block (305) and the middle connecting block (306).

8. The multi-point ultrasonic probe calibration tool according to claim 1, characterized in that: A plurality of coarse circular through holes (103) arranged equidistantly in the transverse direction are provided on both sides of the calibration tool body (100), and a plurality of groups of fine circular through holes (104) are distributed between the coarse circular through holes (103) for the marker (200) to pass through.

9. The multi-point ultrasonic probe calibration tool according to claim 8, characterized in that: The marker (200) includes a coarse marker (201) for its calibration function, and a fine marker (202) for determining the sequence number of the coarse marker (201); The coarse markers (201) pass through the coarse circular through holes (103) and are arranged in a horizontally equidistant manner; The thin marker (202) passes through the thin circular through hole (104) and is located between the thick markers (201).

10. The multi-point ultrasonic probe calibration tool according to claim 9, characterized in that: The number of thin markers (202) in each group is different. When the number of thin markers (202) in a group is greater than one, they are arranged vertically.

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