Surgical navigation system

Abstract

The application discloses a surgical navigation system, comprising: a magnetic field generator for generating an electromagnetic field; a plurality of electromagnetic locators fixed on a target object, the electromagnetic locators for generating induced current or induced voltage under the electromagnetic field; a controller for acquiring a medical image obtained by shooting the target object on which the plurality of electromagnetic locators are fixed, and determining a conversion matrix between an image coordinate system of the medical image and a locator coordinate system of each electromagnetic locator according to a first position coordinate of each electromagnetic locator in the medical image and a pose of each electromagnetic locator when the medical image is shot, the pose of the electromagnetic locator being determined based on the induced current or induced voltage generated by the electromagnetic locator under the electromagnetic field; the controller is further used for acquiring a real-time pose of the electromagnetic locator, fusing the real-time pose with the medical image according to the conversion matrix and displaying a fusion result, and realizing surgical navigation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hand surgery navigation, in particular to a surgery navigation system. BACKGROUND

[0002] Fracture or broken bone refers to complete or partial fracture of bone structure, which is more common in children and the elderly, and also occurs in young and middle-aged people. Knowing the location and specific shape of the fracture or broken bone part, medical personnel can restore the fracture or broken bone part to its original state and perform fixation treatment. Currently, the conventional treatment methods include manual reduction + plaster fixation, manual reduction under fluoroscopy + external fixation support fixation, and open plate rigid fixation. However, the fracture or broken bone part is wrapped by skin, so that the medical personnel cannot accurately locate the specific shape of the fracture or broken bone part by visual observation when using manual reduction treatment. If the intraoperative fluoroscopy method is used to obtain the position of the broken bone, the radiation damage to the doctor and the patient will be increased, and the real-time three-dimensional spatial position of the broken bone cannot be completely understood. If the open surgery method is used, it will increase the additional large incision, increase the pain of the patient, and also increase the risk of infection. SUMMARY

[0003] The present application provides a surgery navigation system to solve the problems in the related art.

[0004] Specifically, the present application is realized by the following technical scheme:

[0005] The present application provides a surgery navigation system, comprising:

[0006] a magnetic field generator for generating an electromagnetic field;

[0007] a plurality of electromagnetic locators fixed on a target object, the electromagnetic locators being used to generate induced current or induced voltage under the electromagnetic field;

[0008] a controller for acquiring a medical image obtained by photographing the target object fixed with the plurality of electromagnetic locators, and determining a conversion matrix between an image coordinate system of the medical image and a locator coordinate system of each electromagnetic locator according to a first position coordinate of each electromagnetic locator in the medical image and a pose of each electromagnetic locator when the medical image is photographed, the pose of the electromagnetic locator being determined based on the induced current or induced voltage generated by the electromagnetic locator under the electromagnetic field;

[0009] The controller is further configured to acquire a real-time pose of the electromagnetic locator, fuse the real-time pose with the medical image according to the conversion matrix, and display a fusion result.

[0010] Optionally, at least part of the electromagnetic locators in the surgery navigation system serve as master electromagnetic locators.

[0011] The main electromagnetic positioner includes:

[0012] A fixation needle, the tip of which is used to be implanted into the target object;

[0013] An electromagnetic coil assembly is fixed to a fixed pin. The electromagnetic coil assembly is used to generate the induced current or induced voltage under the electromagnetic field. The electromagnetic coil assembly is provided with a positioning mark so that the controller can determine the conversion matrix according to the positioning mark.

[0014] Optionally, at least some of the electromagnetic positioners in the surgical navigation system serve as secondary electromagnetic positioners;

[0015] The secondary electromagnetic positioner includes:

[0016] A fixation needle, the tip of which is used to be implanted into the target object;

[0017] An electromagnetic coil assembly is fixed to a pin, and the electromagnetic coil assembly is used to generate the induced current or induced voltage under the electromagnetic field.

[0018] Optionally, the electromagnetic coil assembly includes:

[0019] An electromagnetic coil unit, wherein the electromagnetic coil unit is provided with an electromagnetic positioning coil, the electromagnetic positioning coil being used to generate induced current or induced voltage under the electromagnetic field;

[0020] The fixing unit includes a first connecting part and a second connecting part, wherein the first connecting part is used to fix the electromagnetic coil unit and the second connecting part is used to fix the fixing pin.

[0021] Optionally, the second connecting part is provided with a collet nut, which is connected to a collet provided on the fixing pin.

[0022] Optionally, the electromagnetic coil assembly further includes:

[0023] A mounting bracket is used to fix the electromagnetic coil unit and the fixing unit, and the mounting bracket is provided with a mounting connector.

[0024] The electromagnetic coil unit is provided with a first through hole that mates with the mounting connector, and the electromagnetic coil unit is fixed to the mounting bracket through the first through hole and the mounting connector.

[0025] Optionally, the end face of the electromagnetic coil unit that contacts the fixing frame is provided with a first anti-slip structure, and the end face of the fixing frame that contacts the electromagnetic coil unit is provided with a second anti-slip structure, with the first anti-slip structure abutting against the second anti-slip structure.

[0026] Optionally, the mounting bracket is provided with an anti-misinsertion structure, which is adapted to the anti-misinsertion structure on the electromagnetic coil unit.

[0027] Optionally, the positioning marker includes at least two marker balls;

[0028] The marker ball is embedded in the receiving groove on the fixed frame, or the marker ball is injection molded onto the fixed frame.

[0029] Optionally, the electromagnetic positioner is made of non-magnetic metal.

[0030] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:

[0031] In this embodiment of the invention, electromagnetic navigation tracking technology is used to track the electromagnetic locator rigidly connected to the fractured bone in real time, achieving real-time tracking of the spatial pose of each fracture segment. The displayed results show no image drift and have high accuracy, which can guide medical staff in surgical repositioning operations. Furthermore, there is no need to take real-time pictures of the patient during the operation, which can reduce the radiation dose to the patient from medical image capture during the operation.

[0032] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0033] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0034] Figure 1 This is a schematic diagram of the structure of a surgical navigation system according to an exemplary embodiment of the present invention;

[0035] Figure 2a This is a schematic diagram of the structure of a secondary electromagnetic positioner shown in an exemplary embodiment of the present invention;

[0036] Figure 2b This is a partial structural schematic diagram of a secondary electromagnetic positioner shown in an exemplary embodiment of the present invention;

[0037] Figure 2c This is a partial structural schematic diagram of another auxiliary electromagnetic positioner shown in an exemplary embodiment of the present invention;

[0038] Figure 2d This is a schematic diagram of the structure of a main electromagnetic positioner shown in an exemplary embodiment of the present invention;

[0039] Figure 2e This is a partial structural schematic diagram of a main electromagnetic positioner shown in an exemplary embodiment of the present invention;

[0040] Figure 3 This is a flowchart illustrating a surgical navigation method according to an exemplary embodiment of the present invention. Detailed Implementation

[0041] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0042] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms “a,” “the,” and “the” used in this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0043] It should be understood that although the terms first, second, third, etc., may be used in this invention to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first information may also be referred to as second information without departing from the scope of this invention, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to a determination."

[0044] Figure 1 This is a schematic diagram illustrating the structure of a surgical navigation system according to an exemplary embodiment of the present invention. The surgical navigation system includes: a magnetic field generator 1, a controller 2, and multiple electromagnetic positioners, wherein a portion of the multiple electromagnetic positioners can be used as auxiliary electromagnetic positioners 3, and another portion as primary electromagnetic positioners 4. The controller 2 is connected to the magnetic field generator 1, the auxiliary electromagnetic positioners 3, and the primary electromagnetic positioners 4 respectively.

[0045] Magnetic field generator 1 can be activated under the control of controller 2 to generate a variable electromagnetic field, causing the electromagnetic locator located in this electromagnetic field to generate an induced current / voltage. The characteristics of the induced current / voltage depend on the position and orientation of the electromagnetic locator and the combination of the strength and phase of the changing magnetic field. Controller 2 can acquire this induced current / voltage and convert it into digital data before sending it to an external controller to calculate the pose of the electromagnetic locator. Alternatively, the controller can calculate the pose of the corresponding electromagnetic locator based on the induced current / voltage to track the pose of the electromagnetic locator in the magnetic field coordinate system in real time. This pose is the pose of the locator's coordinate system relative to the magnetic field coordinate system. The pose includes position parameters and attitude parameters, which can be represented using six degrees of freedom. The position parameters in the six degrees of freedom refer to the spatial coordinates (x, y, z), and the attitude parameters are horizontal rotation angle, pitch angle, and roll angle.

[0046] Figure 2a This is a schematic diagram of the structure of a secondary electromagnetic positioner shown in an exemplary embodiment of the present invention. See also: Figure 2a The auxiliary electromagnetic positioner 3 includes a fixing pin 31 and an electromagnetic coil assembly 32.

[0047] Figure 2b This is a partial structural schematic diagram of a secondary electromagnetic positioner according to an exemplary embodiment of the present invention. The fixing pin 31 in the figure may include a pin head 311, a pin tail 312, and a pin body 313. The pin head 311 and the pin tail 312 are respectively located at both ends of the pin body 313. The fixing pin 31 can be integrally formed. The pin head 311 of the fixing pin 31 can be implanted into the target object, and the electromagnetic coil assembly 32 can be fixed to the pin tail 312 or the pin body 313.

[0048] The fixation pin is made of a material that does not generate or affect a magnetic field and can be clearly distinguished from the bone and tissue in medical images. It can be, but is not limited to, non-magnetic metals such as stainless steel and titanium alloys. The target object can be the tissue or organ of a patient requiring surgery, such as a fractured leg bone.

[0049] See Figure 2aThe electromagnetic coil assembly 32 includes an electromagnetic coil unit 321 and a fixing unit 322. The electromagnetic coil unit is equipped with an electromagnetic positioning coil, which can generate an induced current / voltage under an electromagnetic field. The fixing unit 322 includes a first connecting portion 3221 and a second connecting portion 3222. The first connecting portion 3221 is used to fix the electromagnetic coil unit 321, and the second connecting portion 3222 is used to fix the fixing pin 31. The auxiliary electromagnetic coil assembly may also include a fixing frame 33, through which the electromagnetic coil unit 321 can be fixedly connected to the first connecting portion 3221 of the fixing unit 322. The fixing frame is made of a material that does not generate a magnetic field or affect a magnetic field, and may be, but is not limited to, hard plastics such as POM (polyoxymethylene) or PEEK (polyetheretherketone).

[0050] Figure 2c This is a partial structural schematic diagram of another auxiliary electromagnetic positioner shown in an exemplary embodiment of the present invention. See also: Figure 2c The mounting bracket 33 is provided with a mounting joint 331. The mounting joint 331 is not limited to the raised cylinder shown in the figure, but can also be a raised ring. The electromagnetic coil unit 321 is provided with a first through hole that mates with the mounting joint 331. The electromagnetic coil unit 321 can be sleeved on the mounting joint 331 through the first through hole to achieve fixed installation with the mounting bracket 33.

[0051] It should be noted that the number of mounting joints 331 on the fixation frame 33 is not limited to the one shown in the figure. Multiple mounting joints 331 can be used. Correspondingly, a corresponding number of first through holes need to be provided at the relative positions of the electromagnetic coil units, with each first through hole fitting onto one mounting joint. Providing multiple mounting joints prevents rotational slippage between the fixation frame and the electromagnetic coil unit, preventing positional changes in the fixation frame and electromagnetic coil unit during surgery that could lead to inaccurate positioning and navigation during surgical procedures, thus affecting the operation.

[0052] In another embodiment, fastening screws can be provided on the electromagnetic coil unit, and threaded through holes 332 can be provided at the relative positions of the fixing frame, so that the fixing frame and the electromagnetic coil unit can be installed together and then tightened by fastening screws to prevent rotational slippage between the fixing frame and the electromagnetic coil unit.

[0053] The mounting bracket may also be equipped with an anti-misinsertion structure, which is adapted to the anti-misinsertion structure on the electromagnetic coil unit. In one embodiment, the anti-misinsertion structure on the mounting bracket may be, but is not limited to, an anti-misinsertion pin 333, to mate with an anti-misinsertion hole on the electromagnetic coil unit. In another embodiment, the anti-misinsertion structure on the mounting bracket may be, but is not limited to, an anti-misinsertion hole, to mate with an anti-misinsertion pin on the electromagnetic coil unit.

[0054] The first connecting portion 3221 of the fixing unit may include a connecting body and a bolt. The connecting body has a through hole for the bolt to pass through and connect to the fixing frame. To prevent rotational slippage between the fixing unit and the fixing frame, a first anti-slip structure can be provided on the end face of the first connecting portion that contacts the fixing frame, and a second anti-slip structure can be provided on the end face of the fixing frame that contacts the first connecting portion. After the fixing frame is installed on the fixing unit, the first anti-slip structure of the first connecting portion abuts against the second anti-slip structure of the fixing frame, preventing the electromagnetic coil unit from being affected by changes in the position of the fixing frame during surgery, which could lead to inaccurate navigation and positioning during surgical navigation and affect the surgery. The anti-slip structure may, but is not limited to, use a toothed structure on the end face of the fixing frame that contacts the first connecting portion.

[0055] The second connection of the fixing unit can be a collet nut 3222, see [reference]. Figure 2b The collet nut 3222 can be connected to the collet 314 located on the fixing pin. When installing the fixing unit and the fixing pin, the fixing pin can be directly inserted into the collet, and the collet nut can be rotated to clamp the fixing pin. The installation is convenient.

[0056] Figure 2d This is a schematic diagram of the structure of a main electromagnetic positioner according to an exemplary embodiment of the present invention. Figure 2e This is a partial structural schematic diagram of a main electromagnetic positioner according to an exemplary embodiment of the present invention. See also: Figure 2d and Figure 2e Similar to the auxiliary electromagnetic positioner, the main electromagnetic positioner includes a fixing pin 41 and an electromagnetic coil assembly 42. The specific structure of the fixing pin and the installation method of the fixing pin and the electromagnetic coil assembly are similar to those of the auxiliary electromagnetic positioner, and will not be described in detail here.

[0057] See Figure 2e The difference between the main electromagnetic positioner and the auxiliary electromagnetic positioner is that the main electromagnetic positioner has a positioning mark on its mounting frame for coordinate calibration.

[0058] In one embodiment, a receiving groove can be provided in the mounting joint, and the positioning mark 422 can be embedded in the receiving groove, or the positioning mark can be injection molded into the receiving groove. The positioning mark is not limited to the marking ball shown in the figure; it can also be a cube or a hemisphere, etc. The position of the marking ball is not limited to the receiving groove of the mounting joint; it can be placed at any position on the mounting bracket. The number of marking balls is not limited to the two shown in the figure; it can be three, four, or even more.

[0059] In another embodiment, a marker ball can be directly set at the tail or body of the fixing needle, thus eliminating the need for a fixing bracket, which reduces material costs and simplifies installation.

[0060] In another embodiment, the electromagnetic positioning coil can be directly set inside or on the surface of the fixing pin, thus eliminating the need to install the electromagnetic coil unit, which can reduce material costs and simplify installation.

[0061] The following is combined Figure 1 , Figures 2a-2e The process of surgical navigation is explained in detail.

[0062] Figure 3 This is a flowchart illustrating a surgical navigation method in an exemplary embodiment of the present invention, applied to a controller. See also... Figure 3 The method may include the following steps:

[0063] Step 301: Obtain medical images of a target object with multiple fixed electromagnetic locators.

[0064] Before surgery, electromagnetic locators need to be fixed to the target object. Taking a fractured tibia as an example, to enable positioning and navigation of each segment of the tibia during surgery, at least one electromagnetic locator can be fixed to each segment. For example, if the tibia fracture results in three segments, a fixation pin can be implanted in each segment, and an electromagnetic coil assembly can be installed on each pin. The multiple electromagnetic locators fixed to the target object can be partially primary and partially secondary; for example, two of the three electromagnetic locators on the three segments can be primary and one secondary. Alternatively, all electromagnetic locators can be primary, such as installing one primary electromagnetic locator on each of the three segments.

[0065] If both primary and secondary electromagnetic locators are fixed to the target object, the number of primary electromagnetic locators can be one or more. The number of primary electromagnetic locators is related to the number of marker balls on each locator. It is necessary to ensure that the total number of marker balls on the multiple electromagnetic locators fixed to the target object is not less than four to achieve accurate registration with the image coordinate system. For example, if a primary electromagnetic locator has four marker balls, only one primary electromagnetic locator needs to be fixed to the target object; if a primary electromagnetic locator has two marker balls, two primary electromagnetic locators need to be fixed to the target object.

[0066] When the main electromagnetic locator is fixed to the patient's shinbone, the electromagnetic coil assembly is located outside the patient's body. The electromagnetic coil assembly is equipped with positioning marks for coordinate system calibration. With the help of the electromagnetic coil assembly, it is possible to avoid making a large surgical incision on the patient.

[0067] After the electromagnetic positioner is secured, medical personnel can use an external fixator to initially stabilize the shinbone to avoid secondary trauma. Then, a three-dimensional medical image is obtained by capturing images of the target object. The imaging equipment can be, but is not limited to, CT (computed tomography), PET (positron emission tomography), and MR (magnetic resonance) equipment. The controller can acquire the medical image of the target object from the imaging equipment. The medical image displays not only the scan information of the target object but also information about the electromagnetic positioner.

[0068] Before attaching the electromagnetic locators, a medical image (not containing information about the electromagnetic locators) can be taken of the target object to facilitate preliminary diagnosis by medical personnel. This medical image can then be used to determine the number of broken bone segments on the target object, allowing for the attachment of the appropriate number of electromagnetic locators. This medical image can be, but is not limited to, X-ray images, CT images, PET images, MR images, etc.

[0069] It should be noted that when taking medical images, the fixation frame can be installed on the fixation needle without installing the electromagnetic coil unit. After the medical image is taken and coordinate calibration is required, the electromagnetic coil unit can be installed on the fixation frame for coordinate calibration.

[0070] Step 302: Determine the first transformation matrix between the image coordinate system of the medical image and the locator coordinate system of each electromagnetic locator based on the first position coordinates of each electromagnetic locator in the medical image and the pose of each electromagnetic locator when the medical image was captured.

[0071] The pose of the electromagnetic positioner is determined based on the induced current / voltage generated by the electromagnetic positioner under the electromagnetic field.

[0072] Determining the first transformation matrix between the image coordinate system and the locator coordinate system specifically includes the following steps:

[0073] S1. Based on the pose of the electromagnetic locator when capturing medical images, convert the second position coordinates of the electromagnetic locator in the locator coordinate system into the third position coordinates in the magnetic field coordinate system of the electromagnetic field.

[0074] The controller can acquire the induced current / voltage generated by each electromagnetic locator under the electromagnetic field, and calculate the pose of each electromagnetic locator in the magnetic field coordinate system based on the induced current / voltage. The pose of each electromagnetic locator is represented as {A1,A2,...,Ai,...,An}, where n represents the number of electromagnetic locators fixed on the target object, and the pose Ai represents the pose of the locator coordinate system of the i-th electromagnetic locator relative to the magnetic field coordinate system.

[0075] The second position coordinates, also known as the position coordinates of the positioning markers in their respective locator coordinate systems, can be characterized by the known position coordinates of the marker ball in its respective locator coordinate system. Because the electromagnetic positioning coil is mounted on the fixed frame, and the marker ball is embedded in the fixed frame, the electromagnetic positioning coil and the marker ball have a fixed relative positional relationship. This relative positional relationship can be preset or obtained in advance and is used to characterize the second position coordinates.

[0076] If the arrangement of the marker balls on each master electromagnetic locator is the same, then each master electromagnetic locator has the same second position coordinates. Taking a target object with two fixed master electromagnetic locators and two marker balls on each master electromagnetic locator as an example, the second position coordinates of the marker balls on the master electromagnetic locator can be represented as Ball{Ball1, Ball2}, where Ball1 and Ball2 represent the position coordinates of the two marker balls in their respective locator coordinate systems. Therefore, Q1 = A1*Ball1, Q2 = A1*Ball2, Q3 = A2*Ball1, Q4 = A2*Ball2, and the position coordinates of the four marker balls in the magnetic field coordinate system can be calculated, denoted as Q{Q1, Q2, Q3, Q4}.

[0077] S2. Determine the second transformation matrix between the image coordinate system and the magnetic field coordinate system based on the first position coordinate and the third position coordinate.

[0078] Identifying the marker sphere of the main electromagnetic device in a medical image allows us to determine the coordinates of the sphere's center within the image, denoted as P{P1,P2,P3,P4}. By registering three-dimensional points between P{P1,P2,P3,P4} and Q{Q1,Q2,Q3,Q4}, we can fit the second transformation matrix T2 between the image coordinate system and the magnetic field coordinate system. The optimal T2 can be fitted using, but is not limited to, the least squares method.

[0079] S3. Determine the first transformation matrix based on the pose of the electromagnetic locator and the second transformation matrix when capturing medical images.

[0080] The pose Ai represents the pose of the locator coordinate system of the i-th electromagnetic locator relative to the magnetic field coordinate system. -1 This represents the transformation matrix between the magnetic field coordinate system and the locator coordinate system of the i-th electromagnetic locator.

[0081] Therefore, according to T1 i =Ai -1 *T2 calculates the first transformation matrix T1 between each image coordinate system and the locator coordinate system of each electromagnetic locator. For example, the transformation matrix from the image coordinate system to the locator coordinate system of the first electromagnetic locator is T11 = A1. -1*T2, the transformation matrix from the image coordinate system to the locator coordinate system of the second electromagnetic locator is T12=A2 -1 *T2, in sequence, has now completed the calibration between the coordinate systems of each locator and the image coordinate system. T1 can be used to unify the real-time pose of each electromagnetic locator and the position information of the target object in the medical image to the same coordinate system, thus achieving linkage registration.

[0082] Step 303: Obtain the real-time pose of each electromagnetic locator, and fuse the real-time pose of each electromagnetic locator with the medical image according to the first transformation matrix and display the fusion result.

[0083] Therefore, navigation and positioning of each fracture segment can be performed based on the real-time pose of each electromagnetic locator {A1',A2',...,Ai',...,An'}, via B 磁场 =Ai'*T1*B ct Calculate B 磁场 B ct B provides the location data of each broken bone segment in medical images. 磁场 The position data of each segment in the electromagnetic field coordinate system is used to unify the real-time pose of each electromagnetic locator and the position information of the target object in the medical image into the magnetic field coordinate system, and render and display the fracture pose in real time (on the monitor) to guide medical personnel to perform surgical repositioning operations based on the currently displayed real-time fracture pose, thereby realizing the visual navigation of the operation.

[0084] In this embodiment, electromagnetic navigation tracking technology is used to track the electromagnetic locator rigidly connected to the fractured bone in real time, achieving real-time tracking of the spatial pose of each fracture segment. The displayed results show no image drift and have high accuracy, which can guide medical staff in surgical repositioning operations. Furthermore, there is no need to take real-time pictures of the patient during the operation, which can reduce the radiation dose to the patient from medical imaging during the operation.

[0085] It should be noted that although several units / modules or sub-units / modules of the electronic device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of the present invention, the features and functions of two or more units / modules described above can be embodied in one unit / module. Conversely, the features and functions of one unit / module described above can be further divided and embodied by multiple units / modules.

[0086] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A surgical navigation system, characterized in that, include: A magnetic field generator is used to generate electromagnetic fields. Multiple electromagnetic locators are fixed to a target object, wherein the multiple electromagnetic locators are respectively fixed to each fracture segment of the target object, and at least one electromagnetic locator is fixed to each fracture segment. The electromagnetic locators are used to generate induced current or induced voltage under the electromagnetic field. The controller is used to acquire medical images of a target object with multiple fixed electromagnetic locators, and to determine the transformation matrix between the image coordinate system of the medical image and the locator coordinate system of each electromagnetic locator based on the first position coordinates of each electromagnetic locator in the medical image and the pose of each electromagnetic locator when the medical image was captured. The pose of the electromagnetic locator is determined based on the induced current or induced voltage generated by the electromagnetic locator under the electromagnetic field. The controller is also used to acquire the real-time pose of the electromagnetic locator, fuse the real-time pose with the medical image according to the transformation matrix, and display the fusion result.

2. The surgical navigation system according to claim 1, characterized in that, At least some of the electromagnetic locators in the surgical navigation system serve as the main electromagnetic locator. The main electromagnetic positioner includes: A fixation needle, the tip of which is used to be implanted into the target object; An electromagnetic coil assembly is fixed to a fixed pin. The electromagnetic coil assembly is used to generate the induced current or induced voltage under the electromagnetic field. The electromagnetic coil assembly is provided with a positioning mark so that the controller can determine the conversion matrix according to the positioning mark.

3. The surgical navigation system according to claim 1, characterized in that, At least some of the electromagnetic positioners in the surgical navigation system serve as secondary electromagnetic positioners. The secondary electromagnetic positioner includes: A fixation needle, the tip of which is used to be implanted into the target object; An electromagnetic coil assembly is fixed to a pin, and the electromagnetic coil assembly is used to generate the induced current or induced voltage under the electromagnetic field.

4. The surgical navigation system according to claim 2 or 3, characterized in that, The electromagnetic coil assembly includes: An electromagnetic coil unit, wherein the electromagnetic coil unit is provided with an electromagnetic positioning coil, the electromagnetic positioning coil being used to generate induced current or induced voltage under the electromagnetic field; The fixing unit includes a first connecting part and a second connecting part, wherein the first connecting part is used to fix the electromagnetic coil unit and the second connecting part is used to fix the fixing pin.

5. The surgical navigation system according to claim 4, characterized in that, The second connecting part is provided with a collet nut, which is connected to a collet provided on the fixing pin.

6. The surgical navigation system according to claim 4, characterized in that, The electromagnetic coil assembly also includes: A mounting bracket is used to fix the electromagnetic coil unit and the fixing unit, and the mounting bracket is provided with a mounting connector. The electromagnetic coil unit is provided with a first through hole that mates with the mounting connector, and the electromagnetic coil unit is fixed to the mounting bracket through the first through hole and the mounting connector.

7. The surgical navigation system according to claim 6, characterized in that, The end face of the electromagnetic coil unit that contacts the fixing frame is provided with a first anti-slip structure, and the end face of the fixing frame that contacts the electromagnetic coil unit is provided with a second anti-slip structure, with the first anti-slip structure abutting against the second anti-slip structure.

8. The surgical navigation system according to claim 6, characterized in that, The mounting bracket is equipped with an anti-misinsertion structure, which is compatible with the anti-misinsertion structure on the electromagnetic coil unit.

9. The surgical navigation system according to claim 6, characterized in that, The positioning marker contains at least two marker balls; The marker ball is embedded in the receiving groove on the fixed frame, or the marker ball is injection molded onto the fixed frame.

10. The surgical navigation system according to claim 6, characterized in that, The electromagnetic locator is made of non-magnetic metal.

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