Surgical navigation system and method

Abstract

The invention provides a surgical navigation system and method, and the method comprises the steps: determining a target magnetic field correction through a magnetic positioning module according to the obtained structural characteristics of a surgical instrument, correcting magnetic field measurement data obtained by a magnetic field sensor according to the target magnetic field correction, and obtaining target magnetic field data; determining a first coordinate of the magnetic field sensor under a magnetic coordinate system of the magnetic positioning module based on the target magnetic field data, and registering the magnetic coordinate system and an image coordinate system of the target image image by the navigation host based on the first coordinate and an actual relative position relation between the image mark point and the magnetic field sensor, the surgical instrument is navigated based on the registered magnetic coordinate system and image coordinate system and the magnetic positioning data of the surgical instrument provided by the magnetic positioning module, the influence of the surgical instrument on the magnetic field is fully considered, and the target magnetic field correction is determined based on the structural characteristics of the surgical instrument to correct the magnetic field measurement data; the accuracy of registration is improved, and the surgical navigation precision is further improved.

Description

TECHNICAL FIELD

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

[0002] Surgical navigation is a technology that uses computer technology, medical imaging, spatial positioning and real-time tracking technology to help surgeons accurately locate lesions, plan paths and guide instrument operation during surgery.

[0003] In recent years, positioning technology based on magnetic fields has gradually become an important development direction in the field of surgical navigation due to its advantages such as not being affected by line-of-sight obstruction, being able to work in enclosed spaces, and being small in size. Magnetic positioning technology uses alternating magnetic fields or static magnetic fields as signal sources, and through the integration of a micro magnetic sensor at the end of a surgical instrument, the magnetic field strength and direction are detected in real time, and then the position and attitude of the surgical instrument in three-dimensional space are calculated.

[0004] However, existing magnetic positioning technology still faces many challenges, such as not considering the influence of the metal characteristics of surgical instruments on the magnetic field, resulting in low accuracy of the system. Therefore, there is an urgent need for a surgical navigation solution with high positioning accuracy. SUMMARY

[0005] The purpose of the embodiments of the present application is to provide a surgical navigation system and method to solve the above technical problems.

[0006] In one aspect, a surgical navigation system is provided, comprising: including a navigation host, a magnetic positioning module comprising a magnetic field sensor, and a reference frame, the reference frame being fixedly provided with at least three non-collinear image marker points and the magnetic field sensor; The magnetic positioning module is configured to obtain the structural characteristics of a surgical instrument, determine a target magnetic field correction amount based on the structural characteristics, correct the magnetic field measurement data obtained by the magnetic field sensor based on the target magnetic field correction amount to obtain target magnetic field data, and determine a first coordinate of the magnetic field sensor in a magnetic coordinate system of the magnetic positioning module based on the target magnetic field data. The navigation host is configured to register the magnetic coordinate system and an image coordinate system of a target image based on the first coordinate and an actual relative position relationship between the image marker points and the magnetic field sensor, and navigate the surgical instrument based on the registered magnetic coordinate system and image coordinate system, and magnetic positioning data of the surgical instrument provided by the magnetic positioning module; the target image is obtained based on image scanning of an implementation object fixed on the reference frame, and the target image includes the image marker points.

[0007] In one of the embodiments, the magnetic positioning module is configured to determine a target interference source model corresponding to the structural characteristics according to a correspondence between a plurality of preset structural characteristics and a plurality of preset interference source models, and determine a target magnetic field correction amount according to the target interference source model; the structural characteristics include at least one of an instrument material type and an instrument size.

[0008] In one of the embodiments, the target interference source model is a target function fitted based on a test position and a test magnetic field variation amount; the test position is a position within a magnetic field range generated by the magnetic positioning module, and the test magnetic field variation amount is a magnetic field variation amount caused when the surgical instrument is placed at the test position. The magnetic positioning module is configured to estimate an estimated position of the surgical instrument within the magnetic field range, and determine the target magnetic field data according to the estimated position and the target function.

[0009] In one of the embodiments, the surgical navigation system further includes an optical positioning module, and the reference frame is fixedly provided with an optical marker point. The optical positioning module is configured to determine a second coordinate of the optical marker point in an optical coordinate system of the optical positioning module. The navigation host is configured to register the optical coordinate system and the image coordinate system based on the second coordinate and an actual relative position relationship between the image marker point and the optical marker point, and navigate the surgical instrument based on the registered optical coordinate system and image coordinate system and optical positioning data of the surgical instrument provided by the optical positioning module.

[0010] In one of the embodiments, the navigation host is configured to determine a target positioning module with better positioning quality from the magnetic positioning module and the optical positioning module during navigation, and determine the position of the surgical instrument based on positioning data of the surgical instrument provided by the target positioning module.

[0011] In one of the embodiments, the navigation host is configured to determine the magnetic positioning module as the target positioning module when it is determined that an optical occlusion rate of the optical positioning module is greater than a preset occlusion rate threshold, and otherwise, determine the optical positioning module as the target positioning module. Or, The navigation host is configured to determine the magnetic positioning module as the target positioning module when it is determined that a magnetic signal-to-noise ratio of the magnetic positioning module is greater than a preset magnetic signal-to-noise ratio threshold, and otherwise, determine the optical positioning module as the target positioning module.

[0012] In one of the embodiments, the navigation host is further configured to determine that the magnetic coordinate system, the optical coordinate system and the image coordinate system are re-registered when a preset re-registration condition is met during the navigation, and to navigate the surgical instrument based on the re-registered magnetic coordinate system, optical coordinate system and image coordinate system.

[0013] In one of the embodiments, the navigation host is configured to determine that the preset re-registration condition is met when a positioning difference between the magnetic positioning module and the optical positioning module meets a preset difference condition, according to the magnetic positioning data of the surgical instrument provided by the magnetic positioning module and the optical positioning data of the surgical instrument provided by the optical positioning module during the navigation.

[0014] In one of the embodiments, the navigation host is further configured to determine a moving speed of the surgical instrument during the navigation, to determine a target refresh frame rate corresponding to the moving speed according to a correspondence between preset moving speed intervals and preset refresh frame rates, and to cause the magnetic positioning module to calculate the position of the surgical instrument based on the target refresh frame rate.

[0015] In another aspect, a surgical navigation method is also provided, which is applied to any of the surgical navigation systems described above, and the method comprises: The magnetic positioning module acquires a structural characteristic of the surgical instrument, determines a target magnetic field correction amount according to the structural characteristic, corrects the magnetic field measurement data acquired by the magnetic field sensor according to the target magnetic field correction amount to obtain target magnetic field data, and determines a first coordinate of the magnetic field sensor in a magnetic coordinate system of the magnetic positioning module based on the target magnetic field data. The navigation host registers the magnetic coordinate system and an image coordinate system of a target image based on the first coordinate and an actual relative position relationship between the image marker point and the magnetic field sensor, and navigates the surgical instrument based on the registered magnetic coordinate system and image coordinate system and the magnetic positioning data of the surgical instrument provided by the magnetic positioning module; the target image is obtained based on image scanning of an implementation object fixed on the reference frame, and the target image includes the image marker point.

[0016] The surgical navigation system and method provided by the application, the magnetic positioning module determines the target magnetic field correction amount according to the structural characteristics of the surgical instrument obtained, corrects the magnetic field measurement data obtained by the magnetic field sensor according to the target magnetic field correction amount, obtains target magnetic field data, determines the first coordinate of the magnetic field sensor in the magnetic coordinate system of the magnetic positioning module based on the target magnetic field data, and the navigation host corrects the magnetic coordinate system and the image coordinate system of the target image based on the actual relative position relationship between the first coordinate and the image marker point and the magnetic field sensor, and navigates the surgical instrument based on the registered magnetic coordinate system and image coordinate system and the magnetic positioning data of the surgical instrument provided by the magnetic positioning module. The influence of the surgical instrument on the magnetic field is fully considered, the target magnetic field correction amount is determined based on the structural characteristics of the surgical instrument to correct the magnetic field measurement data, the accuracy of registration is improved, and the surgical navigation precision is improved.

[0017] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be achieved and obtained by the structure particularly pointed out in the written description, claims and drawings. It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiment or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present application, and those skilled in the art can also obtain other drawings according to the provided drawings without creative labor.

[0019] Figure 1 The first mechanism schematic diagram of the surgical navigation system provided by the embodiment of the present application; Figure 2 The second structure schematic diagram of the surgical navigation system provided by the embodiment of the present application; Figure 3 The flowchart of the surgical navigation method provided by the embodiment of the present application. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0021] The embodiment of the present application provides a surgical navigation system, please see Figure 1As shown, the system includes a navigation host 1, a magnetic positioning module 2 including a magnetic field sensor, and a reference frame 3, on which at least three non-collinear image marker points and the magnetic field sensor are fixedly arranged.

[0022] The magnetic positioning module 2 is configured to acquire a structural characteristic of the surgical instrument, determine a target magnetic field correction amount based on the structural characteristic, correct magnetic field measurement data acquired by the magnetic field sensor based on the target magnetic field correction amount, obtain target magnetic field data, and determine a first coordinate of the magnetic field sensor in a magnetic coordinate system of the magnetic positioning module based on the target magnetic field data.

[0023] The navigation host 1 is configured to register the magnetic coordinate system and an image coordinate system of a target image based on the first coordinate and an actual relative positional relationship between the image marker points and the magnetic field sensor, and navigate the surgical instrument based on the registered magnetic coordinate system and image coordinate system and magnetic positioning data of the surgical instrument provided by the magnetic positioning module; the target image is obtained by image scanning of an implementation object fixed on the reference frame, and the target image includes the image marker points.

[0024] The implementation object in the embodiment can be a lesion target of a patient, and the lesion target is fixed on the reference frame 3 so that the relative position of the lesion target and the reference frame 3 is fixed. For example, the patient's bone can be rigidly connected to the reference frame 3, and specifically, a single needle fixing seat can be directly knocked into the patient's bone.

[0025] To facilitate pose measurement, the magnetic field sensor in the embodiment can be a 6-degree-of-freedom electromagnetic sensor, and the image marker points can be spherical marker points.

[0026] The surgical navigation system can further include an image scanning module configured to image scan an implementation object fixed on the reference frame 3 to obtain a scan image. In one embodiment, the scan image can be directly used as the target image, and in another embodiment, the scan image can be processed by three-dimensional reconstruction technology to obtain a corresponding three-dimensional reconstruction image, which is used as the target image. The image coordinate system of the target image can be pre-set in the navigation host 1.

[0027] Next, the registration process of the magnetic coordinate system and the image coordinate system of the target image in the surgical navigation system is described in detail.

[0028] When the surgical navigation system includes the magnetic positioning module 2, the magnetic coordinate system of the magnetic positioning module 2 needs to be registered with the image coordinate system of the target image, so as to obtain the conversion relationship between the magnetic coordinate system and the image coordinate system.

[0029] Before the surgery, the navigation host 1 can obtain the reference coordinates of the image marker points in the reference coordinate system, which is a coordinate system established in the real space in advance, such as a coordinate system of the real space based on the reference frame 3. The reference coordinates of the image marker points can be obtained by measurement.

[0030] After the implementation object is fixed on the reference frame 3, the navigation host 1 can obtain the target image based on the scanning result of the image scanning module, so as to obtain the image coordinates of the image marker points in the image coordinate system in the target image.

[0031] The navigation host 1 obtains the first conversion relationship between the reference coordinate system and the image coordinate system according to the reference coordinates of the image marker points and the image coordinates of the image marker points.

[0032] Since the actual relative position relationship between the magnetic field sensor and the image marker point is determined, the navigation host 1 can obtain the reference coordinates of the magnetic field sensor in the reference coordinate system according to the actual relative position relationship and the reference coordinates of the image marker point. The second conversion relationship between the reference coordinate system and the magnetic coordinate system can be obtained according to the reference coordinates of the magnetic field sensor and the first coordinates of the magnetic field sensor in the magnetic coordinate system. The third conversion relationship between the magnetic coordinate system and the image coordinate system can be obtained according to the first conversion relationship and the second conversion relationship, so as to realize the registration of the magnetic coordinate system and the image coordinate system of the target image.

[0033] During the surgical navigation process, the navigation host 1 can fuse the target image obtained based on the scanning during the surgery and the target image obtained based on the scanning before the surgery to obtain the intraoperative target image, and display the intraoperative target image through the display module, so as to realize real-time display during the surgery. At the same time, the magnetic positioning module 2 determines the magnetic positioning data of the surgical instrument in the magnetic coordinate system according to the data obtained by the magnetic field sensor on the surgical instrument. The navigation host 1 determines the third coordinates of the surgical instrument in the image coordinate system based on the third conversion relationship and the magnetic positioning data of the surgical instrument, and realizes real-time navigation. For example, the third coordinates are directly used as the actual position coordinates of the surgical instrument in the corresponding intraoperative target image.

[0034] It can be understood that when the target image before the surgery is fused with the target image during the surgery, image fusion can be realized through image automatic registration technology, so as to realize seamless connection of accurate surgery planning and real-time navigation.

[0035] It should be noted that the preoperative scanning and the intraoperative scanning can be realized by the same device, that is, the image scanning module is composed of one scanning unit, such as an MRI tomographic scanning unit or a CT scanning unit.

[0036] Of course, the intraoperative scanning and the intraoperative scanning can also be realized by different devices, at this time, the image scanning module is composed of two scanning units, such as, the preoperative scanning can be realized by an MRI tomographic scanning unit or a CT scanning unit, and the intraoperative scanning can be realized by a mobile X-ray machine or an intraoperative ultrasonic unit.

[0037] It can be understood that the surgical instrument is usually a metal product, and the metal product will produce eddy current effect and magnetic hysteresis effect in the changing electromagnetic field. The superposition of the two effects will distort the spatial distribution of the original electromagnetic field generated by the transmitter in the magnetic positioning module 2, resulting in deviation of the magnetic field strength, direction and phase detected by the magnetic field sensor from the theoretical value. Moreover, since the influence of different metal products on the original electromagnetic field is also different, a calibration experiment can be performed in advance to obtain the corresponding relationship between a plurality of preset structure characteristics and a plurality of preset interference source models. Then, in actual application, the magnetic positioning module 2 can determine the target interference source model corresponding to the structure characteristics of the surgical instrument according to the corresponding relationship between the plurality of preset structure characteristics and the plurality of preset interference source models, and determine the target magnetic field correction amount according to the target interference source model; the structure characteristics include at least one of the instrument material type and the instrument size. The instrument material type can be the type of metal, and the instrument size can include but is not limited to the length, thickness, shape, etc. of the instrument.

[0038] In an embodiment, the target interference source model is a target function fitted based on a test position and a test magnetic field change amount; the test position is a position within the magnetic field range generated by the magnetic positioning module 2, and the test magnetic field change amount is a magnetic field change amount caused when the surgical instrument is placed at the test position; the magnetic positioning module 2 is used to estimate an estimated position of the surgical instrument within the magnetic field range, and to determine the target magnetic field correction amount according to the estimated position and the target function.

[0039] The calibration experiment process will be described in detail below.

[0040] The target of the correction is to estimate as accurately as possible the interference ΔB (target magnetic field correction amount) caused to the receiver position (the position of the magnetic field sensor on the reference frame 3) when the surgical instrument is placed within the magnetic field range of the magnetic positioning module 2, and then subtract the interference ΔB from the actual magnetic field measurement data measured by the receiver, so as to obtain the target magnetic field data under the condition close to no interference, and based on which the correct pose can be calculated. Therefore, the influence of the surgical instrument with various structure characteristics on the magnetic field data measurement of the magnetic field sensor on the reference frame 3 in the magnetic positioning module 2 can be determined by means of calibration.

[0041] Firstly, the surgical instruments can be classified according to different thicknesses, different lengths and different brands of stainless steel materials, so as to obtain different types of surgical instruments, i.e. surgical instruments with different structure characteristics.

[0042] Then, an initial interference source model of the surgical instrument in the surgical area is established according to the structural characteristics of the surgical instrument.

[0043] Finally, the above various initial interference source models are tested. For example, a surgical instrument with a certain structural characteristic is placed at different test positions within the magnetic field range of the magnetic positioning module 2, and the magnetic field change (i.e., the test magnetic field change) relative to the magnetic field range without the surgical instrument is recorded. According to the different test positions and the corresponding test magnetic field change, a function relationship between the position of the surgical instrument with the structural characteristic in the magnetic field range and the interference can be fitted, and the function relationship is stored in the navigation host 1 as a preset interference source model.

[0044] It should be noted that in actual application, when the surgical instrument is placed in the magnetic field range of the magnetic positioning module 2, the estimated position of the surgical instrument in the magnetic field range can be estimated according to the state parameters of the transmitter, such as the current and frequency of the transmitter, and then the target magnetic field correction amount corresponding to the estimated position is determined according to the estimated position and the target function. Then, the magnetic field measurement data obtained by the magnetic field sensor is corrected based on the target magnetic field correction amount to obtain target magnetic field data, and the first coordinate of the magnetic field sensor in the magnetic coordinate system is determined according to the target magnetic field data. In this embodiment, by calibrating the corresponding magnetic field correction amount for each test position, the accuracy of the registration can be improved.

[0045] It can be understood that in some other embodiments, the average of the test magnetic field change at each of the above-mentioned test positions can be used as a fixed interference value corresponding to the surgical instrument with the structural characteristic, and at this time the above-mentioned function relationship is equivalent to a constant function. The constant function is stored in the navigation host 1 as a preset interference source model. At this time, in actual application, there is no need to estimate the position, and the corresponding target magnetic field correction amount can be matched directly according to the structural characteristics of the surgical instrument, which can improve the calculation efficiency to a certain extent.

[0046] In an embodiment, as shown in Figure 2 The surgical navigation system can further include an optical positioning module 4, and at least three optical markers are fixedly arranged on the reference frame 3. The optical markers in this embodiment can be active light-emitting balls, and the relative positions of the image markers, the optical markers, and the magnetic field sensor on the reference frame 3 are fixed.

[0047] The optical positioning module 4 is used to determine the second coordinates of the optical markers in the optical coordinate system of the optical positioning module 4. The navigation host 1 is used to register the optical coordinate system and the image coordinate system based on the second coordinates and the actual relative position relationship between the image markers and the optical markers, and to navigate the surgical instrument based on the registered optical coordinate system and image coordinate system and the optical positioning data of the surgical instrument provided by the optical positioning module 4.

[0048] The registration process of the optical coordinate system and the image coordinate system in the surgical navigation system will be described in detail below.

[0049] The registration process of the optical coordinate system and the image coordinate system is essentially to determine the conversion relationship between the optical coordinate system and the image coordinate system.

[0050] Through the above introduction, the reference coordinates of the image marker points and the first conversion relationship between the reference coordinate system and the image coordinate system can be obtained. Since the actual relative position relationship between the optical marker points and the image marker points is determined, the navigation host 1 can obtain the reference coordinates of the optical marker points in the reference coordinate system according to the actual relative position relationship and the reference coordinates of the image marker points, and can obtain the fourth conversion relationship between the reference coordinate system and the optical coordinate system according to the reference coordinates of the optical marker points and the second coordinates of the optical marker points in the optical coordinate system. The fifth conversion relationship between the optical coordinate system and the image coordinate system can be obtained according to the first conversion relationship and the fourth conversion relationship, thereby realizing the registration of the optical coordinate system and the image coordinate system of the target image.

[0051] In the surgical navigation process, the optical positioning module 4 can determine the optical positioning data of the surgical instrument in the optical coordinate system according to the optical marker points on the surgical instrument. The navigation host 1 determines the fourth coordinates of the surgical instrument in the image coordinate system based on the fifth conversion relationship and the optical positioning data of the surgical instrument, and determines the actual position coordinates of the surgical instrument in the corresponding intraoperative target image according to the fourth coordinates and the corresponding third coordinates at this time. For example, the actual position coordinates of the surgical instrument in the corresponding intraoperative target image can be calculated according to the third coordinates and the corresponding weight values, the fourth coordinates and the corresponding weight values.

[0052] It should be noted that when the surgical navigation system simultaneously includes the magnetic positioning module 2 and the optical positioning module 4, the navigation host 1 can determine the target positioning module with better positioning quality from the magnetic positioning module 2 and the optical positioning module 4 in the navigation process, and determine the position of the surgical instrument mainly based on the positioning data of the surgical instrument provided by the target positioning module.

[0053] In an embodiment, the navigation host 1 is configured to determine the magnetic positioning module 2 as the target positioning module when it is determined that the optical occlusion rate of the optical positioning module 4 is greater than a preset occlusion rate threshold, and otherwise, determine the optical positioning module 4 as the target positioning module; or, the navigation host 1 is configured to determine the magnetic positioning module 2 as the target positioning module when it is determined that the magnetic signal-to-noise ratio of the magnetic positioning module 2 is greater than a preset magnetic signal-to-noise ratio threshold, and otherwise, determine the optical positioning module 4 as the target positioning module.

[0054] It should be noted that in order to realize optical positioning of the surgical instrument, at least 3 optical marker points should be arranged on the surgical instrument, for example, 4 optical marker points can be arranged.

[0055] For example, the optical occlusion rate can be measured by the number of optical marker points on the surgical instrument that are occluded, or the ratio of the number of optical marker points on the surgical instrument that are occluded to the total number of optical marker points on the surgical instrument.

[0056] For example, the optical occlusion rate can also be measured by the maximum angle between the optical plane formed by the optical marker points on the surgical instrument and the plane of the camera lens of the optical positioning module 4. The reason is that if the maximum angle is greater than a preset angle threshold (i.e., a preset occlusion rate threshold), it means that when the angle of the optical plane formed by the optical marker points changes, the distance between some of the optical marker points recognized by the optical camera will be shortened, which will affect the accuracy of optical positioning. In particular, when the angle between the optical plane formed by the optical marker points and the plane of the camera lens is 90°, all the optical marker points recognized by the optical camera are on a line.

[0057] The magnetic signal-to-noise ratio is the ratio between the effective magnetic field signal strength and the background magnetic noise strength in the magnetic positioning module 2. For example, the ratio between the magnetic field measurement data measured by the magnetic field sensor on the surgical instrument during navigation and the target magnetic field data obtained during the last registration process can be used as the current magnetic signal-to-noise ratio of the magnetic positioning module 2.

[0058] The optical occlusion rate during surgical navigation reflects the positioning quality of the optical positioning module 4, while the magnetic signal-to-noise ratio reflects the positioning quality of the magnetic positioning module 2 during surgical navigation. The navigation host 1 in this embodiment flexibly selects the target positioning module according to the acquired optical occlusion rate or magnetic signal-to-noise ratio during surgical navigation, thereby improving the flexibility and accuracy of navigation positioning.

[0059] It should be noted that the specific values of the preset occlusion rate threshold and the preset magnetic signal-to-noise ratio threshold in this embodiment can be flexibly set by the developer.

[0060] Determining the position of the surgical instrument based on the positioning data of the surgical instrument provided by the target positioning module means that the positioning data of the surgical instrument provided by the target positioning module is used as the main positioning data, and the actual position coordinates of the surgical instrument in the corresponding intraoperative target image are determined based on the main positioning data.

[0061] For example, if the optical positioning module 4 is determined as the target positioning module, a fifth coordinate of the surgical instrument in the image coordinate system can be determined according to the current optical positioning data of the surgical instrument provided by the optical positioning module 4 and the fifth conversion relationship obtained through the registration, and the fifth coordinate can be directly taken as the actual position coordinate of the surgical instrument in the corresponding intraoperative target image. Of course, a sixth coordinate of the surgical instrument in the image coordinate system can also be determined according to the current magnetic positioning data of the surgical instrument provided by the magnetic positioning module 2 and the third conversion relationship obtained through the registration, and the actual position coordinate of the surgical instrument in the corresponding intraoperative target image can be determined according to the product of the fifth coordinate and the first weight value and the product of the sixth coordinate and the second weight value, where the first weight value is greater than the second weight value.

[0062] To improve the registration accuracy of each real-time scene, in an embodiment, the navigation host 1 is further configured to, during the navigation, determine that the magnetic coordinate system, the optical coordinate system and the image coordinate system meet a preset re-registration condition, and perform navigation on the surgical instrument based on the re-registered magnetic coordinate system, optical coordinate system and image coordinate system.

[0063] The re-registration process is similar to the registration process described above. When the re-registration is triggered, the image scanning can be performed again by the image scanning module to obtain a new target image, and then the new first conversion relationship between the reference coordinate system and the image coordinate system can be determined according to the reference coordinates of the latest obtained image markers in the reference coordinate system and the image coordinates of the image markers in the new target image data.

[0064] Then, the new third conversion relationship between the magnetic coordinate system and the image coordinate system and the new fifth conversion relationship between the optical coordinate system and the image coordinate system can be obtained by referring to the similar processes described above, and the specific processes are not described herein.

[0065] It can be understood that the re-registration condition can be flexibly set by the developer. For example, the navigation host 1 is configured to determine that the preset re-registration condition is met when the positioning difference between the magnetic positioning module 2 and the optical positioning module 4 meets a preset difference condition, according to the magnetic positioning data of the surgical instrument provided by the magnetic positioning module 2 and the optical positioning data of the surgical instrument provided by the optical positioning module 4 during the navigation.

[0066] For example, if the sixth coordinate of the surgical instrument in the image coordinate system is (x1, y1, z1) according to the magnetic positioning data of the surgical instrument and the third conversion relationship, and the fifth coordinate of the surgical instrument in the image coordinate system is (x2, y2, z2) according to the optical positioning data of the surgical instrument and the fifth conversion relationship, the positioning difference between the magnetic positioning module and the optical positioning module can be determined according to the difference between the sixth coordinate and the fifth coordinate to determine whether the positioning difference meets the preset difference condition.

[0067] For example, if |x1-x2| is greater than a first threshold value, |y1-y2| is greater than a second threshold value, and |z1-z2| is greater than a third threshold value, it is determined that the positioning difference between the magnetic positioning module and the optical positioning module meets the preset difference condition, otherwise it does not meet.

[0068] For example, if |x1-x2| is greater than a first threshold value, |y1-y2| is greater than a second threshold value, and |z1-z2| is greater than a third threshold value, it is determined that the positioning difference between the magnetic positioning module and the optical positioning module meets the preset difference condition, otherwise it does not meet. For example, if |x1-x2| is greater than a first threshold value, |y1-y2| is greater than a second threshold value, and |z1-z2| is greater than a third threshold value, it is determined that the positioning difference between the magnetic positioning module and the optical positioning module meets the preset difference condition, otherwise it does not meet.

[0069] For example, if it is determined that the difference between the magnetic positioning data and the optical positioning data in the continuous N sampling periods is greater than the preset difference threshold value, it is determined that the positioning difference between the magnetic positioning module and the optical positioning module meets the preset difference threshold value, otherwise it does not meet. The specific value of N can be flexibly set by the developer, for example, it can be 5.

[0070] Considering that the magnetic positioning module 2 needs to correct the magnetic field measurement data, the required computing resources are relatively large, in an embodiment, the navigation host 1 is also used to determine the moving speed of the surgical instrument during navigation, determine the target refresh frame rate corresponding to the moving speed of the surgical instrument according to the corresponding relationship between the preset moving speed interval and the preset refresh frame rate, and supply the magnetic positioning module 2 with the target refresh frame rate for calculating the position of the surgical instrument.

[0071] In this embodiment, the navigation host 1 is provided with a corresponding relationship between a plurality of preset moving speed intervals and a plurality of preset refresh frame rates. For example, the corresponding relationship can be as shown in Table 1:

[0072] It should be noted that the larger the preset moving speed interval, the higher the corresponding preset refresh frame rate, that is, f2 is greater than f1. In this embodiment, different refresh frame rates are set for different moving speeds of the surgical instrument, which enhances the environmental adaptability of the magnetic positioning module 2.

[0073] By setting a higher refresh frame rate for a higher moving speed interval, the consumption of computing resources is reduced as much as possible on the basis of ensuring the timeliness and accuracy of positioning when the surgical instrument moves at a low speed, and the timely refresh of positioning is ensured when the surgical instrument moves at a high speed.

[0074] The surgical navigation system provided in this embodiment can realize automatic registration without human intervention, and has short registration time and high registration accuracy. The surgical preparation time is greatly shortened, and the navigation accuracy is improved.

[0075] Furthermore, through dual-module complementary positioning technology, it boasts strong anti-interference capabilities, integrating the high-precision spatial positioning of optical navigation with the anti-interference dynamic tracking of electromagnetic navigation. This reduces intraoperative image drift and achieves sub-millimeter-level positioning accuracy. The appropriate positioning module can be selected in real-time, minimizing operational interruptions and eliminating the need for frequent equipment calibration due to environmental interference, thus improving surgical smoothness.

[0076] Based on the same inventive concept, in one embodiment, a surgical navigation method based on any of the surgical navigation systems described above is provided. Please refer to [link to relevant documentation]. Figure 3 As shown, it includes: S11: The magnetic positioning module acquires the structural characteristics of the surgical instrument, determines the target magnetic field correction amount based on the structural characteristics, corrects the magnetic field measurement data acquired by the magnetic field sensor based on the target magnetic field correction amount, obtains the target magnetic field data, and determines the first coordinate of the magnetic field sensor in the magnetic coordinate system of the magnetic positioning module based on the target magnetic field data.

[0077] S12: The navigation host registers the magnetic coordinate system with the image coordinate system of the target image based on the first coordinate and the actual relative position relationship between the image marker and the magnetic field sensor. Based on the registered magnetic coordinate system and image coordinate system, as well as the magnetic positioning data of the surgical instruments provided by the magnetic positioning module, the navigation host navigates the surgical instruments. The target image is obtained by scanning the object fixed on the reference frame, and the target image includes the image marker.

[0078] In one embodiment, the magnetic positioning module determines the target magnetic field correction amount based on the structural characteristics of the surgical instrument, including: The magnetic positioning module determines the target interference source model corresponding to the structural characteristics of the surgical instrument based on the correspondence between multiple preset structural characteristics and multiple preset interference source models, and determines the target magnetic field correction amount based on the target interference source model; the structural characteristics include at least one of instrument material type and instrument size.

[0079] In one embodiment, the target interference source model is a target function obtained by fitting the test position and the test magnetic field change; the test position is a position within the magnetic field range generated by the magnetic positioning module, and the test magnetic field change is the change in magnetic field caused when the surgical instrument is placed at the test position; The step of determining the target magnetic field correction amount based on the target interference source model includes: The magnetic positioning module estimates the estimated position of the surgical instrument within the magnetic field range, and determines the target magnetic field correction amount based on the estimated position and the objective function.

[0080] In one embodiment, the surgical navigation system further includes an optical positioning module, and optical markers are fixedly disposed on the reference frame; the method further includes: The optical positioning module determines the second coordinates of the optical marker point in the optical coordinate system of the optical positioning module; The navigation host registers the optical coordinate system with the image coordinate system based on the second coordinates and the actual relative positional relationship between the image marker and the optical marker. Based on the registered optical coordinate system and the image coordinate system, as well as the optical positioning data of the surgical instrument provided by the optical positioning module, the navigation host navigates the surgical instrument.

[0081] In one embodiment, the method further includes: During navigation, the navigation host determines the position of the surgical instrument based on the positioning data of the surgical instrument provided by the target positioning module, which has better positioning quality than the magnetic positioning module and the optical positioning module.

[0082] In one embodiment, the navigation host determines a target positioning module with better positioning quality from the magnetic positioning module and the optical positioning module during navigation, including: When the navigation host determines that the optical occlusion rate of the optical positioning module is greater than a preset occlusion rate threshold, it determines that the magnetic positioning module is the target positioning module; otherwise, it determines that the optical positioning module is the target positioning module. or, When the navigation host determines that the magnetic signal-to-noise ratio of the magnetic positioning module is less than a preset magnetic signal-to-noise ratio threshold, it determines that the magnetic positioning module is the target positioning module; otherwise, it determines that the optical positioning module is the target positioning module.

[0083] In one embodiment, the method further includes: When the navigation host determines that the preset reregistration conditions are met during the navigation process, it reregisters the magnetic coordinate system, the optical coordinate system, and the image coordinate system, and navigates the surgical instrument based on the reregistered magnetic coordinate system, optical coordinate system, and image coordinate system.

[0084] In one embodiment, the navigation host determines during navigation that preset reregistration conditions are met, including: During navigation, the navigation host determines that the preset re-registration condition is met when the positioning difference between the magnetic positioning module and the optical positioning module meets the preset difference condition based on the magnetic positioning data of the surgical instrument provided by the magnetic positioning module and the optical positioning data of the surgical instrument provided by the optical positioning module.

[0085] In one embodiment, the method further includes: During navigation, the navigation host determines the moving speed of the surgical instrument and determines the target refresh frame rate corresponding to the moving speed based on the correspondence between the preset moving speed range and the preset refresh frame rate, so that the magnetic positioning module can calculate the position of the surgical instrument based on the target refresh frame rate.

[0086] It should be understood that, for the sake of brevity, the content described in the above embodiments will not be repeated in this embodiment.

[0087] It should be understood that although the steps in the flowchart above are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart above may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0088] Those skilled in the art will understand that Figure 1 and Figure 2 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the application of the present application. A specific surgical navigation system may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0089] Based on the same inventive concept, embodiments of this application also provide a computer program product, including a computer program that, when executed by a processor, implements any of the methods described above.

[0090] The program code for executing the computer program product of this application can be written in any combination of one or more programming languages. The program code can be executed entirely on the user device, partially on the user device, as a standalone software package, partially on the user device and partially on a remote device, or entirely on a remote device.

[0091] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, etc.) containing computer-usable program code.

[0092] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer-readable storage media according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, as well as combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0093] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0094] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of user-operated steps to be executed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0095] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this application. Therefore, the drawings only show components relevant to this application and are not drawn according to the actual number, shape, and size of components in implementation. In actual implementation, the shape, quantity, and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex. The structures, proportions, sizes, etc., shown in the accompanying drawings are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modification to the structure, change in the proportional relationship, or adjustment of the size, without affecting the effect and purpose that this application can produce, should still fall within the scope of the technical content disclosed in this application. At the same time, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are only for clarity of description and are not intended to limit the scope of implementation of this application. Changes or adjustments in their relative relationships, without substantially changing the technical content, should also be considered within the scope of implementation of this application.

[0096] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the document does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0097] As illustrated herein, unless the context clearly indicates otherwise, the words “a,” “an,” “an,” and / or “the” do not specifically refer to the singular and may also include the plural. Generally speaking, the terms “comprising” and “including” only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0098] The definitions used herein, such as the terms “having,” “may have,” “comprising,” or “may include,” indicate the presence of the corresponding function, operation, element, etc., and do not limit the presence of one or more other functions, operations, elements, etc. Furthermore, it should be understood that the terms “comprising” or “having” as used herein indicate the presence of the features, figures, steps, operations, elements, components, or combinations thereof described in the specification, without excluding the presence or addition of one or more other features, figures, steps, operations, elements, components, or combinations thereof.

[0099] The prefixes such as "first" and "second" used in this application embodiment are merely for distinguishing different descriptive objects and do not limit the position, order, priority, quantity, or content of the described objects. The use of ordinal numbers and other prefixes used to distinguish descriptive objects in this application embodiment does not constitute a limitation on the described objects. For statements regarding the described objects, please refer to the claims or the context of the embodiments. The use of such prefixes should not constitute unnecessary limitations. Furthermore, in the description of this embodiment, unless otherwise stated, "multiple" means two or more.

[0100] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0101] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A surgical navigation system, characterized in that, It includes a navigation host, a magnetic positioning module containing a magnetic field sensor, and a reference frame, wherein at least three non-collinear image markers and the magnetic field sensor are fixedly mounted on the reference frame; The magnetic positioning module is used to acquire the structural characteristics of the surgical instrument, determine the target magnetic field correction amount based on the structural characteristics, correct the magnetic field measurement data acquired by the magnetic field sensor based on the target magnetic field correction amount to obtain the target magnetic field data, and determine the first coordinate of the magnetic field sensor in the magnetic coordinate system of the magnetic positioning module based on the target magnetic field data. The navigation host is used to register the magnetic coordinate system with the image coordinate system of the target image based on the first coordinates and the actual relative positional relationship between the image marker and the magnetic field sensor, and to navigate the surgical instrument based on the registered magnetic coordinate system and the image coordinate system, as well as the magnetic positioning data of the surgical instrument provided by the magnetic positioning module; the target image is obtained by scanning the object fixed on the reference frame, and the target image includes the image marker.

2. The surgical navigation system according to claim 1, characterized in that, The magnetic positioning module is used to determine the target interference source model corresponding to the structural characteristics based on the correspondence between multiple preset structural characteristics and multiple preset interference source models, and to determine the target magnetic field correction amount based on the target interference source model; the structural characteristics include at least one of instrument material type and instrument size.

3. The surgical navigation system according to claim 2, characterized in that, The target interference source model is a target function obtained by fitting the test position and the change in the test magnetic field; the test position is the position within the magnetic field range generated by the magnetic positioning module, and the change in the test magnetic field is the change in the magnetic field caused when the surgical instrument is placed at the test position; The magnetic positioning module is used to estimate the position of the surgical instrument within the magnetic field range, and to determine the target magnetic field correction amount based on the estimated position and the objective function.

4. The surgical navigation system according to any one of claims 1-3, characterized in that, The surgical navigation system also includes an optical positioning module, and optical markers are fixedly set on the reference frame; The optical positioning module is used to determine the second coordinates of the optical marker point in the optical coordinate system of the optical positioning module; The navigation host is used to register the optical coordinate system with the image coordinate system based on the second coordinates and the actual relative positional relationship between the image marker and the optical marker, and to navigate the surgical instrument based on the registered optical coordinate system and the image coordinate system, as well as the optical positioning data of the surgical instrument provided by the optical positioning module.

5. The surgical navigation system according to claim 4, characterized in that, The navigation host is used to determine the target positioning module with better positioning quality from the magnetic positioning module and the optical positioning module during navigation, and to determine the position of the surgical instrument based on the positioning data of the surgical instrument provided by the target positioning module.

6. The surgical navigation system according to claim 5, characterized in that, The navigation host is used to determine the magnetic positioning module as the target positioning module when the optical occlusion rate of the optical positioning module is greater than a preset occlusion rate threshold; otherwise, it determines the optical positioning module as the target positioning module. or, The navigation host is used to determine the magnetic positioning module as the target positioning module when the magnetic signal-to-noise ratio of the magnetic positioning module is greater than a preset magnetic signal-to-noise ratio threshold; otherwise, it determines the optical positioning module as the target positioning module.

7. The surgical navigation system according to claim 4, characterized in that, The navigation host is also used to re-register the magnetic coordinate system, the optical coordinate system and the image coordinate system when a preset re-registration condition is met during the navigation process, and to navigate the surgical instrument based on the re-registered magnetic coordinate system, optical coordinate system and image coordinate system.

8. The surgical navigation system according to claim 7, characterized in that, The navigation host is used to determine, during navigation, that a preset re-registration condition is met when the positioning difference between the magnetic positioning module and the optical positioning module meets a preset difference condition, based on the magnetic positioning data of the surgical instrument provided by the magnetic positioning module and the optical positioning data of the surgical instrument provided by the optical positioning module.

9. The surgical navigation system according to any one of claims 1-3, characterized in that, The navigation host is also used to determine the moving speed of the surgical instrument during navigation, and to determine the target refresh frame rate corresponding to the moving speed according to the correspondence between the preset moving speed range and the preset refresh frame rate, so that the magnetic positioning module can calculate the position of the surgical instrument based on the target refresh frame rate.

10. A surgical navigation method, characterized in that, The method, applied to the surgical navigation system as described in any one of claims 1-9, comprises: The magnetic positioning module acquires the structural characteristics of the surgical instrument, determines the target magnetic field correction amount based on the structural characteristics, corrects the magnetic field measurement data acquired by the magnetic field sensor based on the target magnetic field correction amount to obtain the target magnetic field data, and determines the first coordinate of the magnetic field sensor in the magnetic coordinate system of the magnetic positioning module based on the target magnetic field data. The navigation host registers the magnetic coordinate system with the image coordinate system of the target image based on the first coordinates and the actual relative positional relationship between the image markers and the magnetic field sensor. Based on the registered magnetic coordinate system and the image coordinate system, as well as the magnetic positioning data of the surgical instrument provided by the magnetic positioning module, the navigation host navigates the surgical instrument. The target image is obtained by scanning the object fixed on the reference frame, and the target image includes the image markers.

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