A calibration frame for medical image registration

Abstract

The utility model provides a kind of calibration frame for medical image registration belongs to medical instrument technical field;The calibration frame for medical image registration includes support and the mark body being set on the support, the support includes connecting frame, first beam, second beam and third beam, the first beam the second beam and the third beam are connected with the connecting frame respectively, the mark body is distributed on the one side of the first beam the second beam and the third beam away from connecting frame, and the mark body is along the beam longitudinal interval arrangement of its place.Simultaneously can guarantee that mark body in image is clearly visible and mutually does not overlap in the above-mentioned scheme, the outline of all mark body can be identified from two images, it is easy to operate, and registration time in operation can be effectively saved.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a calibration frame for medical image registration. Background Technology

[0002] In intraoperative navigation applications, to save time during surgery, preoperative planning using preoperative CT images is typically necessary, such as pre-designing the screw placement path. During surgery, the patient's position differs from the preoperative plan, requiring registration of the preoperative plan to the patient's intraoperative position. Specifically, in pedicle screw placement surgery, a common approach is to first reconstruct a 3D digital model from preoperative CT data, then register the 3D model with two or more 2D images taken during surgery (intraoperative X-rays) to achieve the goal of registering the preoperative plan to the patient's intraoperative position. Two intraoperative X-rays can be used to reconstruct a 3D scene from the two 2D images using a binocular 3D reconstruction algorithm, and then the reconstructed 3D scene is matched with the preoperative 3D model. During binocular 3D reconstruction, a calibration plate is required. Specifically, before taking intraoperative X-rays, the calibration plate is placed near the surgical incision, and two X-ray images are taken at any two angles using a C-arm.

[0003] The principle of a calibration plate is to implant CT-imageable markers, such as steel balls, into CT-transparent material at a specific size. These markers are then clearly identifiable on the X-ray images, serving as feature points to assist the algorithm in camera (C-arm) calibration and binocular 3D reconstruction. Existing calibration plates are typically planar or obtuse-angled. During X-ray imaging in surgery, the plate's position needs to be adjusted to ensure all markers are clearly visible in both images. Otherwise, some markers may be too close to be identified in the 2D images, or even overlap, preventing binocular 3D reconstruction and wasting valuable time in the surgical registration process. Utility Model Content

[0004] This invention provides a calibration frame for medical image registration, which solves the technical problem that existing calibration plates are usually planar or obtuse-angled, requiring adjustment of the calibration plate's position during X-ray imaging in surgery, resulting in a cumbersome operation.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0006] A calibration frame for medical image registration includes a support and markers disposed on the support. The support includes a connecting frame, a first beam, a second beam, and a third beam. The first beam, the second beam, and the third beam are respectively connected to the connecting frame. The markers are distributed on the side of the first beam, the second beam, and the third beam opposite to the connecting frame, and the markers are arranged at intervals along the longitudinal direction of the beam.

[0007] Optionally, the marker body includes labeled spheres and unlabeled spheres, wherein the size of the labeled spheres is different from the size of the unlabeled spheres.

[0008] Optionally, each beam is provided with one labeled sphere and multiple unlabeled spheres, and the order of the labeled spheres on each beam is different.

[0009] Optionally, the numbered spheres on the first beam are ordered as first among the marked bodies on the first beam, the numbered spheres on the second beam are ordered as second among the marked bodies on the second beam, and the numbered spheres on the third beam are ordered as third among the marked bodies on the third beam.

[0010] Optionally, each beam is embedded with four markers, with the markers on the first beam having a spacing ratio of 10:3:7; the markers on the second beam having a spacing ratio of 1:3:1; and the markers on the third beam having a spacing ratio of 6:5:9.

[0011] Optionally, the connecting frame includes a main rod and two support rods perpendicularly connected to the main rod. The two support rods are spaced apart and distributed on both sides of the main rod. The main rod is perpendicularly connected to the second beam, one support rod is perpendicularly connected to the first beam, and the other support rod is perpendicularly connected to the third beam.

[0012] Optionally, both the first beam and the third beam are inclined relative to the second beam, and the inclination angles of the first beam and the third beam are opposite.

[0013] Optionally, the support may be made of plastic or polyetheretherketone (PEEK).

[0014] The beneficial effects of the above-mentioned technical solution of this utility model are as follows:

[0015] In the above scheme, the calibration frame used for medical image registration can take two X-ray images without moving, while ensuring that the markers in the images are clearly visible and do not overlap. The outlines of all markers can be identified from the two images. The operation is simple and can effectively save registration time during surgery. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the calibration frame of this utility model;

[0017] Figure 2 This is a side view of the calibration frame of this utility model.

[0018] [Figure Labels]

[0019] 1. First beam;

[0020] 2. Second beam;

[0021] 3. The third beam;

[0022] 4. Labeled spheres;

[0023] 5. Non-standard spheres;

[0024] 6. Connecting bracket. Detailed Implementation

[0025] To make the technical problems, technical solutions and advantages of this utility model clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0026] like Figures 1-2 As shown, an embodiment of the present invention provides a calibration frame for medical image registration, including a support and markers disposed on the support. The support includes a connecting frame 6, a first beam 1, a second beam 2, and a third beam 3. The first beam 1, the second beam 2, and the third beam 3 are respectively connected to the connecting frame 6. The markers are distributed on the side of the first beam 1, the second beam 2, and the third beam 3 facing away from the connecting frame 6, and the markers are arranged at intervals along the longitudinal direction of the beams they are located.

[0027] like Figure 1 As shown, the marking body includes a labeled sphere 4 and a non-labeled sphere 5, the size of the labeled sphere 4 being different from the size of the non-labeled sphere 5.

[0028] Each beam has one labeled sphere 4 and multiple unlabeled spheres 5, and the labeled spheres 4 are arranged differently on each beam to facilitate the determination of the beam number.

[0029] Among them, the numbered sphere 4 on the first beam 1 is ranked first among the markings on the first beam 1, the numbered sphere 4 on the second beam 2 is ranked second among the markings on the second beam 2, and the numbered sphere 4 on the third beam 3 is ranked third among the markings on the third beam 3.

[0030] In this embodiment, each beam is embedded with four markers. The spacing ratio of the markers on the first beam 1 is 10:3:7; the spacing ratio of the markers on the second beam 2 is 1:3:1; and the spacing ratio of the markers on the third beam 3 is 6:5:9. By using the different spacing between the markers, the numbers of all markers can be quickly identified in two two-dimensional images for pairing.

[0031] like Figure 1 As shown, the connecting frame 6 includes a main rod and two support rods perpendicularly connected to the main rod. The two support rods are spaced apart and distributed on both sides of the main rod. One end of the main rod is perpendicularly connected to the second beam 2, one support rod is perpendicularly connected to the first beam 1, and the other support rod is perpendicularly connected to the third beam 3, so that the markers are distributed in three different orientations.

[0032] like Figure 2 As shown, both the first beam 1 and the third beam 3 are inclined relative to the second beam 2, and the inclination angles of the first beam 1 and the third beam 3 are opposite. Taking the upper plane of the second beam 2 as a reference, the first beam 1 and the third beam 3 form angles of +8º and -8º with it, respectively.

[0033] The dimensions of the bracket and the marker can be scaled up or down proportionally according to the actual needs of the application scenario. In this embodiment, the diameter of the labeled sphere 4 is 6mm, and the diameter of the unlabeled sphere 5 is 4mm.

[0034] The support is made of a CT-transparent material. In this embodiment, a polymer material such as plastic or polyetheretherketone is used to reduce the interference of the support on the image registration process, making the marker more prominent in the image and facilitating algorithm detection and recognition.

[0035] In the above scheme, the calibration frame for medical image registration can take two X-ray images without moving, while ensuring that the markers in the images are clearly visible and do not overlap. The outlines of all markers can be identified from the two images. The operation is simple and can effectively save registration time during surgery. By setting numbered spheres at different positions on each beam and the unique spacing design between the markers, the numbers of all markers can be quickly identified in the two two-dimensional images for pairing, so as to ensure the success of the calibration and reconstruction algorithm.

[0036] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A calibration frame for medical image registration, characterized in that, The device includes a support frame and markers disposed on the support frame. The support frame includes a connecting frame, a first beam, a second beam, and a third beam. The first beam, the second beam, and the third beam are respectively connected to the connecting frame. The markers are distributed on the side of the first beam, the second beam, and the third beam that is away from the connecting frame, and the markers are arranged at intervals along the longitudinal direction of the beam.

2. The calibration frame for medical image registration according to claim 1, characterized in that, The marker body includes labeled spheres and unlabeled spheres, the size of the labeled spheres being different from the size of the unlabeled spheres.

3. The calibration frame for medical image registration according to claim 2, characterized in that, Each beam has one labeled sphere and multiple unlabeled spheres, and the order of the labeled spheres is different on each beam.

4. The calibration frame for medical image registration according to claim 3, characterized in that, The numbered spheres on the first beam are ranked first among the markings on the first beam, the numbered spheres on the second beam are ranked second among the markings on the second beam, and the numbered spheres on the third beam are ranked third among the markings on the third beam.

5. The calibration frame for medical image registration according to claim 1, characterized in that, Each beam has four markers embedded in it. The spacing ratio of the markers on the first beam is 10:3:7; the spacing ratio of the markers on the second beam is 1:3:1; and the spacing ratio of the markers on the third beam is 6:5:

9.

6. The calibration frame for medical image registration according to claim 1, characterized in that, The connecting frame includes a main rod and two support rods perpendicularly connected to the main rod. The two support rods are spaced apart and distributed on both sides of the main rod. The main rod is perpendicularly connected to the second beam, one support rod is perpendicularly connected to the first beam, and the other support rod is perpendicularly connected to the third beam.

7. The calibration frame for medical image registration according to claim 6, characterized in that, Both the first beam and the third beam are inclined relative to the second beam, and the inclination angles of the first beam and the third beam are opposite.

8. The calibration frame for medical image registration according to claim 1, characterized in that, The support is made of plastic or polyetheretherketone.

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