Magnetic sensor clusters, magnetic navigation and positioning terminals, and magnetic navigation systems

Abstract

This application relates to the field of medical device technology, specifically a magnetic sensor cluster, a magnetic navigation positioning terminal, and a magnetic navigation system. The magnetic sensor cluster includes multiple magnetic sensor modules, each module comprising a first printed circuit board. This circuit board includes a rigid substrate, and a magnetic sensor and multiple imaging elements disposed on the rigid substrate. The imaging elements are all electronic components within the peripheral circuitry of the magnetic sensor. This invention, by integrating the magnetic sensor and imaging elements on a rigid substrate, ensures the stability of the positional relationship between the magnetic sensor and the imaging elements, improving image registration accuracy. Simultaneously, by utilizing existing peripheral circuit components as imaging elements, it simplifies the structure and reduces costs.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a magnetic sensor cluster, a magnetic navigation and positioning terminal, and a magnetic navigation system. Background Technology

[0002] With the continuous development of medical technology, magnetic navigation technology has been widely used in surgical navigation due to its advantages such as non-radiation and high precision. A magnetic navigation system typically includes components such as a magnetic field generator, magnetic sensors, and a processor. The magnetic sensor is a key component of the system, used to collect magnetic field information and transmit it to the processor for processing. One of the core functions of a magnetic navigation system is image registration, that is, obtaining the spatial transformation relationship between the image coordinate system and the magnetic field coordinate system, thereby organically combining preoperative planning with real-time intraoperative navigation.

[0003] However, existing magnetic sensor clusters still suffer from the following problems in magnetic navigation applications: The extraction of existing coil markers from CT (Computed Tomography) and MRI (Magnetic Resonance Imaging) images is not accurate enough, often requiring manual selection, leading to low recognition and extraction accuracy. Adding additional markers and fixed structures not only increases system complexity and marker volume but also necessitates additional calibration processes, prolonging the error chain and reducing overall accuracy. Furthermore, the relative positional relationship between the coil markers and additional markers is prone to change, resulting in inaccurate coil marker coordinates calculated based on the coordinates of the additional markers, affecting image registration accuracy. Utility Model Content

[0004] Therefore, it is necessary to address the technical problems of existing image registration methods in magnetic navigation applications, such as inaccurate extraction of coil markers and the increased complexity caused by the need for additional markers and fixed structures, by providing a magnetic sensor cluster, a magnetic navigation positioning terminal, and a magnetic navigation system.

[0005] A magnetic sensor cluster is characterized in that it includes multiple magnetic sensor modules, each of the magnetic sensor modules including a first printed circuit board, the first printed circuit board including a rigid substrate, and a magnetic sensor and multiple developing elements disposed on the rigid substrate, wherein the multiple developing elements are electronic components in the peripheral circuit of the magnetic sensor.

[0006] In one embodiment, a plurality of the developing elements are arranged around the periphery of the magnetic sensor, or the plurality of the developing elements are arranged on one side of the magnetic sensor.

[0007] In one embodiment, the number of developing elements is two, with the two developing elements respectively arranged on both sides of the magnetic sensor, and the center of the magnetic sensor located at the midpoint of the line connecting the two developing elements.

[0008] In one embodiment, the developing element is a capacitor.

[0009] In one embodiment, a second printed circuit board is also included, the second printed circuit board including a flexible substrate on which a plurality of the magnetic sensor modules are disposed.

[0010] In one embodiment, the flexible substrate is either straight or curved.

[0011] A magnetic navigation and positioning terminal includes a magnetic sensor cluster as described in any of the above embodiments, and further includes a control unit and a wireless communication unit. The control unit is used to supply power to the magnetic sensors in the magnetic sensor cluster and to acquire magnetic field information collected by the magnetic sensors. The wireless communication unit is used to wirelessly transmit the magnetic field information.

[0012] In one embodiment, the magnetic field information is acquired by the control unit from the magnetic sensor using a preset polling strategy. The preset polling strategy includes: the control unit setting up multiple parallel acquisition channels; the control unit dividing all magnetic sensors into multiple acquisition groups; the control unit starting information acquisition for each acquisition group through multiple parallel acquisition channels; and the control unit acquiring the magnetic field information acquired by the magnetic sensor in the corresponding acquisition group in each parallel acquisition channel according to a preset order.

[0013] A magnetic navigation system includes a processor, a magnetic field generator, and a magnetic navigation positioning terminal as described in the above embodiments; the magnetic field generator is used to generate a magnetic field when placed in a surgical environment; the magnetic navigation positioning terminal is used to be attached to the patient's body surface; the processor is used to be electrically connected to the magnetic field transmitter and the magnetic navigation positioning terminal.

[0014] In one embodiment, the processor is further configured to: acquire medical images of the patient; determine image coordinates of multiple voxel points contained in the target area based on the medical images; acquire state information of the magnetic field generated by the magnetic field generator and magnetic field information collected by the magnetic sensor in the magnetic navigation and positioning terminal; determine the magnetic field coordinates of the magnetic sensor based on the state information and the magnetic field information; and acquire the spatial transformation relationship between the image coordinate system and the magnetic field coordinate system based on the image coordinates and the magnetic field coordinates.

[0015] The aforementioned magnetic sensor cluster, magnetic navigation positioning terminal, and magnetic navigation system integrate the magnetic sensor and imaging element onto a rigid PCB (Printed Circuit Board) and optimize their layout design, making the imaging element easier to identify in medical images. This improves the accuracy of magnetic sensor position extraction and reduces manual selection errors. Furthermore, the imaging element is an electronic component in the peripheral circuit of the magnetic sensor that can be clearly displayed in medical images. The imaging element does not require additional setup; instead, it utilizes existing components in the peripheral circuit, thus simplifying and miniaturizing the cluster structure and reducing costs. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a magnetic sensor module in one embodiment of this application;

[0018] Figure 2 This is a schematic diagram of one arrangement of developing elements in an embodiment of this application;

[0019] Figure 3 This is a schematic diagram of another arrangement of the developing element in one embodiment of this application;

[0020] Figure 4 This is a schematic diagram of the structure of a magnetic sensor cluster in one embodiment of this application;

[0021] Figure 5 This is a schematic diagram of the arrangement of multiple magnetic sensor clusters in one embodiment of this application;

[0022] Figure 6 This is a schematic diagram of the structure of a magnetic navigation and positioning terminal in one embodiment of this application;

[0023] Figure 7 This is a schematic diagram of the structure of a magnetic navigation system according to an embodiment of this application.

[0024] Figure label:

[0025] Magnetic sensor module 11, rigid substrate 13, magnetic sensor 14, developing element 15, flexible substrate 17, magnetic sensor cluster 10, control unit 20, wireless communication unit 30, magnetic navigation and positioning terminal 1, processor 2, magnetic field generator 3, magnetic navigation system 100. Detailed Implementation

[0026] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0027] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0028] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0029] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0030] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0031] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0032] One embodiment of this application provides a magnetic sensor cluster 10, which includes multiple magnetic sensor modules 11, see reference. Figure 1 , Figure 1 This is a schematic diagram of the structure of a magnetic sensor module in one embodiment of this application. Each magnetic sensor module 11 includes a first printed circuit board, the first printed circuit board includes a rigid substrate 13, and a magnetic sensor 14 and a plurality of developing elements 15 disposed on the rigid substrate 13. The plurality of developing elements 15 are all electronic components in the peripheral circuit of the magnetic sensor 14.

[0033] In this embodiment, the magnetic sensor cluster 10 is used in a magnetic navigation system. It can be attached to the patient's body surface and collects magnetic field information through the magnetic sensor 14. Combined with medical images, it performs image registration to achieve precise positioning and navigation. The first printed circuit board adopts a rigid PCB design because a rigid PCB has a certain degree of hardness and stability, which can ensure that the relative positional relationship between the magnetic sensor 14 and the imaging element 15 remains unchanged, thereby improving the image registration accuracy.

[0034] The magnetic sensor 14 in the magnetic sensor module 11 is a triaxial magnetic sensor, capable of simultaneously measuring the magnetic field strength in the X, Y, and Z directions. Commonly used magnetic sensor types include Hall effect sensors, magnetoresistive sensors, and fluxgate sensors. In this embodiment, a Hall effect sensor is preferably used, which has advantages such as small size, low power consumption, and high sensitivity, making it suitable for medical navigation scenarios.

[0035] The peripheral circuit of the magnetic sensor 14 refers to the circuit system required to support the normal operation of the magnetic sensor 14, mainly including three parts: power supply circuit, signal conditioning circuit, and data transmission circuit. The power supply circuit is responsible for providing a stable operating voltage to the magnetic sensor 14; if the output of the magnetic sensor 14 is a digital signal, the signal conditioning circuit is responsible for amplifying and filtering the digital signal output by the magnetic sensor 14; if the output of the magnetic sensor 14 is an analog signal, the signal conditioning circuit is responsible for amplifying, filtering, and performing analog-to-digital conversion on the analog signal output by the magnetic sensor 14; the data transmission circuit is responsible for transmitting the processed digital signal to the control unit.

[0036] The electronic components in the peripheral circuit include at least some of the following: resistors, capacitors, inductors, operational amplifiers, analog-to-digital converters, etc. Resistors are mainly used for voltage division, current limiting, and pull-up / pull-down; capacitors are mainly used for filtering, decoupling, and energy storage; inductors are used for filtering and impedance matching; operational amplifiers are used for signal amplification and buffering; and analog-to-digital converters are used to convert analog signals into digital signals.

[0037] In this embodiment, the imaging element 15 refers to an electronic component selected from the peripheral circuit of the magnetic sensor 14 that can be clearly displayed in medical images. These imaging elements 15 do not require additional configuration; instead, they utilize existing components in the peripheral circuit, thereby simplifying and miniaturizing the cluster structure and reducing costs.

[0038] In the PCB design, the magnetic sensor 14 can be located at the center of the PCB, while the imaging components 15 are distributed around the magnetic sensor 14 according to a specific layout. The PCB is fabricated using standard PCB manufacturing processes, including substrate material selection, circuit design, photolithography, etching, drilling, electroplating, solder masking, and surface treatment. The substrate material is FR-4 epoxy resin fiberglass board, which has good mechanical strength, electrical insulation, and thermal stability. Component mounting uses surface mount technology to achieve high-density integration and miniaturized design.

[0039] Image registration is a crucial step in magnetic navigation systems, aiming to establish a spatial transformation relationship between the image coordinate system and the magnetic field coordinate system. The image coordinate system refers to the three-dimensional image coordinate system established using medical images such as CT or MRI, while the magnetic field coordinate system is the three-dimensional spatial coordinate system defined by the magnetic field generator. Through image registration, positional information from the magnetic field coordinate system can be mapped to the image coordinate system, thereby achieving real-time navigation and positioning.

[0040] During image registration, for cases where the medical image does not contain the magnetic sensor cluster 10, a spatial transformation relationship between the image coordinate system and the magnetic field coordinate system is established based on the image coordinates of multiple voxel points contained in the patient area of ​​the medical image, and the coordinates of the magnetic sensor 14 in the magnetic field coordinate system calculated based on the magnetic field information collected by the magnetic sensor 14, thereby completing image registration. For cases where the image contains the magnetic sensor cluster 10, a spatial transformation relationship between the image coordinate system and the magnetic field coordinate system is established based on the coordinates of the magnetic sensor 14 in the image coordinate system calculated based on the position of the imaging element 15 in the medical image, and the coordinates of the magnetic sensor 14 in the magnetic field coordinate system calculated based on the magnetic field information collected by the magnetic sensor 14, thereby completing image registration.

[0041] The aforementioned magnetic sensor cluster 10 integrates the magnetic sensor 14 and the imaging element 15 onto a rigid PCB and optimizes their layout design, making the imaging element 15 easier to identify in medical images. This improves the accuracy of magnetic sensor 14 position extraction and reduces manual selection errors. Furthermore, the imaging element 15 is an electronic component in the peripheral circuit of the magnetic sensor 14 that can be clearly displayed in medical images. The imaging element 15 does not require additional configuration; instead, it utilizes existing components in the peripheral circuit, thereby simplifying and miniaturizing the cluster structure and reducing costs.

[0042] Based on any of the above embodiments, see Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of one arrangement of the developing elements in one embodiment of this application. Figure 3 This is a schematic diagram of another arrangement of the developing element in one embodiment of this application, such as... Figure 2 and Figure 3 As shown, a plurality of developing elements 15 are arranged around the periphery of the magnetic sensor 14, or a plurality of developing elements 15 are arranged on one side of the magnetic sensor 14.

[0043] The arrangement of the developing elements 15 is crucial for accurately determining the position of the magnetic sensor 14. Multiple developing elements 15 are necessary because a single developing element 15 can only provide distance information and cannot determine orientation information. In this embodiment, the number of developing elements 15 is at least two to determine the orientation of the magnetic sensor 14 relative to the developing elements 15. Within a certain range, the more developing elements 15 there are, the greater the redundancy. For example, if the spatial position of a developing element 15 is inaccurate or malfunctions, the information from other developing elements 15 can be used to locate the position of the magnetic sensor 14, reducing risk and improving the signal-to-noise ratio. Typically, when the number of developing elements 15 is increased to three or four, it can provide not only position information but also attitude information, i.e., it can provide local 6DoF information. Thus, attitude information is added during image registration, which helps improve registration accuracy.

[0044] There are two main ways to arrange the developing elements 15: surrounding arrangement and one-sided arrangement. Surround arrangement means that the developing elements 15 are distributed on different sides of the magnetic sensor 14, forming a surrounding pattern; one-sided arrangement means that the developing elements 15 are concentrated on one side of the magnetic sensor 14.

[0045] When using a surrounding arrangement, such as Figure 2 As shown in (a), if there are two developing elements 15, they can be arranged on the left and right sides of the magnetic sensor 14 respectively; Figure 2 As shown in (b), if there are 3 developing elements 15, they can be arranged on the left, right, and top sides respectively to form a triangular layout. If there are 4 developing elements 15, they can be arranged on the left, right, top, and bottom sides respectively to form a rectangular layout. If there are 8 developing elements 15, they can be evenly distributed around the magnetic sensor 14 to form an octagonal layout.

[0046] When using a one-sided layout, such as Figure 3 As shown, if there are 3 developing elements 15, they can all be arranged on the left side of the magnetic sensor 14, forming a triangle. If there are 4 developing elements 15, they can all be arranged on the right side of the magnetic sensor 14, forming a rectangle.

[0047] Different calculation methods are used to determine the coordinates of the magnetic sensor 14 depending on its arrangement. For a surrounding arrangement, the coordinates of the magnetic sensor 14 can be estimated by a weighted average of the coordinates of the developing elements 15. For a one-sided arrangement, the coordinates of the magnetic sensor 14 need to be calculated based on the arrangement direction of the developing elements 15 and the pre-calibrated relative distance. For example, a coordinate system can be established based on the positions of the developing elements 15, and then the position of the magnetic sensor 14 in that coordinate system can be pre-calibrated. It is important that the arrangement of the developing elements 15 has directional specificity; otherwise, singularities will occur when establishing the coordinates.

[0048] The coordinates of an element typically refer to the coordinates of its center point. In medical imaging, the outline of the imaging element 15 can be automatically identified using image processing algorithms, and then its center point coordinates can be calculated. For elements with regular shapes, such as circles or rectangles, their geometric center can be calculated directly; for elements with irregular shapes, their centroid or the center of their bounding box can be calculated.

[0049] Based on any of the above embodiments, such as Figure 2 As shown in (a), there are two developing elements 15, which are arranged on both sides of the magnetic sensor 14, and the center of the magnetic sensor 14 is located at the midpoint of the line connecting the two developing elements 15.

[0050] This embodiment employs a surrounding arrangement of two developing elements 15, with the two developing elements 15 located on the left and right sides of the magnetic sensor 14, respectively, and the center of the magnetic sensor 14 precisely located at the midpoint of the line connecting the two developing elements 15. This arrangement has the advantages of simple structure and convenient calculation.

[0051] In this arrangement, the coordinate calculation of the magnetic sensor 14 is very intuitive: assuming the coordinates of the two developing elements 15 are (x1, y1, z1) and (x2, y2, z2) respectively, then the coordinates of the magnetic sensor 14 are ((x1+x2) / 2, (y1+y2) / 2, (z1+z2) / 2), which is the arithmetic mean of the coordinates of the two points.

[0052] Compared to other layout schemes, this symmetrical layout has the following advantages: First, it is simple to calculate and does not require complex geometric transformations; second, the error distribution is uniform and there is no systematic deviation in a certain direction; third, the structure is compact and occupies little space; and finally, it has fewer components, lower cost, and higher reliability.

[0053] In practical applications, the two imaging elements 15 are usually selected from the same type of components, such as two capacitors or resistors of the same specification, to ensure that their display effect in medical images is consistent and facilitates identification and positioning. The distance between the two imaging elements 15 and the magnetic sensor 14 should be moderate, neither too close to avoid mutual interference, nor too far to avoid increasing the size of the PCB board.

[0054] Based on any of the above embodiments, the developing element 15 is a capacitor.

[0055] In this embodiment, the developing element 15 is a capacitor. Capacitors are commonly used electronic components in the peripheral circuit of the magnetic sensor 14, primarily for filtering, decoupling, and energy storage. The peripheral circuit also includes resistors, inductors, operational amplifiers, analog-to-digital converters, and other components, which can also serve as the developing element 15, but capacitors offer some unique advantages.

[0056] The main advantages of using a capacitor as a imaging element 15 include: First, capacitors have good imaging effects in both CT and MR images, especially ceramic and tantalum capacitors, whose metal parts can form obvious high-density areas in the images; second, capacitors have regular shapes, usually rectangular or cylindrical, which facilitates identification and positioning in the images; third, capacitors are of moderate size, neither too large to affect the miniaturization design of the PCB board, nor too small to make them difficult to identify in the images; finally, capacitors are an essential component in the peripheral circuit of the magnetic sensor 14, and choosing a capacitor as an imaging element 15 does not require the addition of additional components, which conforms to the principles of simplified design and reduced costs.

[0057] Based on any of the above embodiments, see Figure 4 , Figure 4 This is a schematic diagram of the structure of a magnetic sensor cluster in one embodiment of this application, as shown below. Figure 4 As shown, the magnetic sensor cluster 10 also includes a second printed circuit board, which includes a flexible substrate 17 on which multiple magnetic sensor modules 11 are disposed.

[0058] The magnetic sensor cluster 10 in this embodiment adopts a rigid-flexible design, including a rigid first printed circuit board and a flexible second printed circuit board. The second printed circuit board uses a flexible substrate material 17, such as polyimide, polyethylene terephthalate, or liquid crystal polymer, which has good flexibility and bendability, allowing it to conform to the curves of the patient's body surface and improve wearing comfort and stability. In one embodiment, the magnetic sensor cluster 10 also includes a fixing component connected to the second printed circuit board for fixing the second printed circuit board to the patient's body surface. The fixing component can be a biocompatible adhesive layer disposed on the bottom surface of the flexible substrate 17 of the second printed circuit board, and can be made of acrylic medical pressure-sensitive adhesive to achieve stable adhesion to the patient's body surface.

[0059] Multiple magnetic sensor modules 11 are mounted on the flexible substrate 17. These modules are implemented via a first printed circuit board, meaning each magnetic sensor module 11 is an independent rigid PCB. The connection methods between the rigid PCB and the flexible substrate 17 are mainly as follows: Soldering connection: Solder pads are pre-reserved on the flexible substrate 17, and the rigid PCB is soldered to the flexible substrate 17 by reflow soldering or manual soldering. Adhesive connection: The rigid PCB is adhered to the flexible substrate 17 using conductive or non-conductive adhesive. Press-fit connection: Press-fit points are designed on both the rigid PCB and the flexible substrate 17, and the connection is achieved by pressing them together using a special clamp or clip. Plug-in connection: Pins are designed on the rigid PCB, and sockets are designed on the flexible substrate 17, achieving connection through plugging and unplugging.

[0060] Based on any of the above embodiments, the thickness of the rigid substrate 13 ranges from 0.8 mm to 2.0 mm, and / or the size of the developing element 15 ranges from 0.5 mm × 0.25 mm to 3.2 mm × 1.6 mm.

[0061] In this embodiment, the rigid substrate 13 is made of FR-4 epoxy resin fiberglass board. Considering that the rigid substrate 13 needs sufficient hardness and stability to ensure that the relative positional relationship between the magnetic sensor 14 and the imaging element 15 is not easily deformed, and considering miniaturization and patient wearing comfort, its thickness is set to a range of 0.8mm to 2.0mm. Furthermore, considering the limitations of PCB manufacturing processes, setting the thickness of the rigid substrate 13 to several commonly used thicknesses such as 0.8mm, 1.0mm, 1.2mm, 1.6mm, and 2.0mm can reduce manufacturing costs and improve production efficiency.

[0062] The dimensions of electronic components range from 0.5mm × 0.25mm to 3.2mm × 1.6mm. Components mounted using surface mount technology typically include sizes such as 0201 (0.6mm × 0.3mm), 0402 (1.0mm × 0.5mm), 0603 (1.6mm × 0.8mm), 0805 (2.0mm × 1.25mm), and 1206 (3.2mm × 1.6mm). The selection of the size of the imaging element 15 needs to balance clear visibility in medical images with a limited size. Therefore, capacitors in 0603 or 0805 packages are preferred for the imaging element 15, as these sizes provide good imaging performance in medical images without excessively increasing the PCB board size.

[0063] Based on any of the above embodiments, the flexible substrate 17 has a straight or arc shape.

[0064] In this embodiment, the flexible substrate 17 of the second printed circuit board can be designed in various shapes to adapt to different clinical application scenarios and patient body shapes. The main shapes include two categories: straight lines and arcs.

[0065] Figure 5 Image (a) shows multiple magnetic sensor clusters 10, each cluster having a linear flexible substrate 17. The linear flexible substrate is elongated and suitable for attachment to relatively flat areas of the patient's body surface, such as the chest, abdomen, or back. The linear design is simple, the manufacturing process is mature, and the cost is low. The length of the linear flexible substrate is typically 10cm to 30cm, and the width is 1cm to 3cm, which can be adjusted according to specific application requirements.

[0066] Figure 5(b) shows multiple magnetic sensor clusters 10, each cluster having a curved flexible substrate 17. The curved flexible substrate can be a simple curve, such as a semicircle or crescent shape, or a complex curve, such as an S-shape or spiral shape. The curved design is suitable for attachment to areas of the patient's body surface with high curvature, such as the head, neck, or joints. The curved flexible substrate can better conform to the patient's body surface curvature, improving wearing stability and comfort. On the curved flexible substrate, without affecting the fit with the patient's skin, magnetic sensors 14 can be arranged more densely in areas with many physiological features, such as areas with high curvature.

[0067] Figure 5 (c) shows multiple magnetic sensor clusters 10, with some clusters having a straight flexible substrate 17 and others having an arc-shaped flexible substrate 17.

[0068] In addition to straight and curved shapes, the flexible substrate 17 can also be designed into irregular structures, such as T-shaped, Y-shaped, or ring-shaped, to meet specific clinical needs. For example, a T-shaped design can cover two intersecting anatomical planes simultaneously; a Y-shaped design can extend from a point in three different directions to cover a wider area; and a ring-shaped design can surround an anatomical structure, such as a limb or neck.

[0069] Different combinations of magnetic sensor clusters 10 can be used to suit different patients and surgical procedures. For example, in spinal surgery, a linear cluster can be placed along the spine, and two arc-shaped clusters can be placed on either side of the rib area; in cranial surgery, multiple arc-shaped clusters can be used to form a hemispherical shape to cover the head; in joint surgery, a ring-shaped cluster can be used to surround the joint, and a linear cluster can be used to extend along the limb. This flexible combination method can better adapt to the differences in body shape among different patients and the special needs of different surgeries, improving the applicability and accuracy of the system.

[0070] Based on any of the above embodiments, see Figure 6 , Figure 6 This is a schematic diagram of the structure of a magnetic navigation and positioning terminal in one embodiment of this application, as shown below. Figure 6 As shown, this embodiment provides a magnetic navigation and positioning terminal 1, which includes multiple magnetic sensor clusters 10 as described in any of the above embodiments, and also includes a control unit 20 and a wireless communication unit 30. The control unit 20 is used to supply power to the magnetic sensors 14 in the magnetic sensor cluster 10 and to acquire the magnetic field information collected by the magnetic sensors 14. The wireless communication unit 30 is used to wirelessly transmit the magnetic field information.

[0071] The magnetic navigation positioning terminal 1 in this embodiment is a complete portable device. In addition to containing multiple magnetic sensor clusters 10, it also includes a control unit 20 and a wireless communication unit 30, forming an independently operating system. This terminal can be attached to the patient's body surface to collect magnetic field information in real time and wirelessly transmit the information to an external processing device for magnetic navigation positioning.

[0072] The control unit 20 is the core of the entire terminal, responsible for system power management, data acquisition, and preliminary processing. The control unit 20 is wired to all magnetic sensor clusters 10, with electrical connections achieved via dedicated cables or flexible circuit boards. The control unit 20 can be located in the following positions:

[0073] Centralized setup: The control unit 20 is centrally located in a small, independent box and connected to each magnetic sensor cluster 10 via flexible connecting cables. This setup facilitates heat dissipation and maintenance.

[0074] Distributed setup: The control unit 20 is decomposed into multiple functional modules, distributed across different magnetic sensor clusters 10, and communicates via a bus. This setup reduces the length and complexity of the connecting cables.

[0075] Integrated configuration: The control unit 20 is directly integrated onto the flexible substrate 17 of a magnetic sensor cluster 10 to form a master control cluster, with other clusters connected to the master control cluster as subordinate clusters. This configuration method has a compact structure.

[0076] In this embodiment, an integrated configuration is preferred, with the control unit 20 integrated onto a larger flexible substrate 17, which also supports part of the magnetic sensor module 11. This design ensures both system compactness and ease of connection with other magnetic sensor clusters 10. The control unit 20 is typically positioned in a relatively flat and less active area of ​​the patient's body, such as the chest or back, to ensure stable connection and reduce motion interference.

[0077] The working principle of the control unit 20 and the peripheral circuit of the magnetic sensor 14 is as follows:

[0078] Power supply: The control unit 20 includes a power management module responsible for converting battery power into the operating voltage required by the magnetic sensor 14, and supplying power to each magnetic sensor module 11 via a power cable. The peripheral circuitry of the magnetic sensor 14 includes a power supply circuit to ensure that the magnetic sensor 14 receives a stable operating voltage.

[0079] Data Acquisition: The control unit 20 includes a data acquisition module, which is connected to each magnetic sensor module 11 via a data cable. The peripheral circuit of the magnetic sensor 14 includes a data transmission circuit, which transmits the digital signal output by the magnetic sensor 14 to the control unit 20.

[0080] The wireless communication unit 30 is responsible for wirelessly transmitting the magnetic field information collected by the control unit 20 to an external processing device, such as a computer or a dedicated navigation workstation. The wireless communication unit 30 can be located in the following positions:

[0081] Integration with control unit 20: The wireless communication unit 30 is directly integrated into the control unit to form a complete control and communication module. This configuration method has a simple structure.

[0082] Independent configuration: The wireless communication unit 30 is housed in a separate small module and connected to the control unit 20 via a short wire. This configuration facilitates heat dissipation and antenna layout.

[0083] External configuration: The wireless communication unit 30 is housed in a detachable external module and connected to the control unit 20 via a standard interface. This configuration facilitates upgrades and maintenance.

[0084] In this embodiment, it is preferable to adopt an integrated configuration with the control unit 20, in which the wireless communication unit 30 is directly integrated into the control unit 20 to form a compact control and communication center.

[0085] Based on any of the above embodiments, this embodiment further refines the internal structure of the control unit 20 and the wireless communication unit 30 to achieve more efficient system control and data transmission.

[0086] The control unit 20 includes the following main modules: a main controller, employing a low-power microcontroller such as an ARM Cortex-M series or STM32 series, responsible for the control and coordination of the entire system; a power management module, responsible for the system's power supply and management, including circuits such as a lithium battery charging controller, a DC-DC converter, and a low-dropout linear regulator; a data acquisition module, responsible for acquiring magnetic field information from multiple magnetic sensor modules 11, including a multi-channel analog-to-digital converter, a multiplexer, and signal conditioning circuitry; and a storage module, used to store system configuration, calibration parameters, and temporary data, including flash memory and random access memory.

[0087] The wireless communication unit 30 includes the following main modules: a wireless transceiver, responsible for transmitting and receiving wireless signals, employing low-power wireless communication technologies such as Bluetooth Low Energy, ZigBee, or Wi-Fi; an antenna, responsible for radiating and receiving wireless signals, which can be a PCB antenna, a ceramic antenna, or an external antenna; and a communication protocol processor, responsible for implementing the wireless communication protocol stack, such as a Bluetooth protocol stack, a ZigBee protocol stack, or a TCP / IP protocol stack. The communication protocol processor can be a separate chip or integrated into the main controller.

[0088] Based on any of the above embodiments, this embodiment describes the acquisition of magnetic field information. The magnetic field information is acquired by the control unit 20 from the magnetic sensor 14 using a preset polling strategy. The preset polling strategy includes:

[0089] The control unit 20 is equipped with multiple parallel acquisition channels; the control unit 20 divides all magnetic sensors 14 into multiple acquisition groups; the control unit 20 starts the information acquisition of each acquisition group through multiple parallel acquisition channels; in each parallel acquisition channel, the control unit 20 sequentially acquires the magnetic field information collected by the magnetic sensors 14 in the corresponding acquisition group in a preset order.

[0090] In this embodiment, the control unit 20 employs a preset polling strategy to acquire magnetic field information from multiple magnetic sensors 14, thereby achieving efficient data acquisition and processing. The polling strategy is a resource scheduling method that achieves resource sharing and efficient utilization by accessing various devices in a specific order.

[0091] In the magnetic navigation system, due to the large number of magnetic sensors 14, this embodiment adopts a parallel polling strategy. By setting up multiple parallel acquisition channels, the magnetic sensors 14 are divided into multiple acquisition groups to achieve parallel acquisition and processing. The specific polling strategy includes the following steps:

[0092] The control unit 20 is equipped with multiple parallel acquisition channels: Internally, the control unit 20 has multiple physically isolated data acquisition channels, each containing an independent analog-to-digital converter (ADC), signal conditioning circuitry, and data buffer. Physical isolation means that these channels do not share hardware resources and can operate simultaneously without interfering with each other. The number of parallel acquisition channels is typically between two and eight, depending on the hardware resources of the control unit 20 and system requirements.

[0093] The control unit 20 divides all magnetic sensors 14 into multiple acquisition groups: based on the number of parallel acquisition channels, all magnetic sensors 14 are evenly distributed into different acquisition groups. Even distribution means that each acquisition group contains approximately the same number of magnetic sensors 14 to balance the workload of each channel. For example, if the system has 24 magnetic sensors 14 and 4 parallel acquisition channels, then each acquisition group contains 6 magnetic sensors 14.

[0094] The control unit 20 initiates information acquisition for each acquisition group through multiple parallel acquisition channels: the control unit 20 simultaneously activates all parallel acquisition channels, initiating the data acquisition process for each acquisition group. Simultaneous activation means that all channels begin working at the same time, achieving true parallel acquisition. This parallel acquisition method can significantly improve the system's sampling rate and real-time performance.

[0095] Within each parallel acquisition channel, the control unit 20 sequentially acquires the magnetic field information collected by the magnetic sensors 14 in the corresponding acquisition group according to a preset order. Within each parallel acquisition channel, the control unit 20 accesses each magnetic sensor 14 in that acquisition group in a preset order to acquire its acquired magnetic field information. The preset order can be a fixed order, such as according to the numerical order of the magnetic sensors 14; or it can be a dynamically adjusted order, such as prioritizing the magnetic sensors 14 based on their importance or data change rate.

[0096] In addition to the basic polling strategy mentioned above, the following optimization strategies can also be adopted:

[0097] Time-division multiplexing strategy: Within each acquisition cycle, time is divided into multiple time slots, and different magnetic sensors 14 operate in different time slots, avoiding the inability to acquire data from many sensors simultaneously. This strategy is suitable for situations where there are a large number of magnetic sensors 14.

[0098] Priority strategy: Based on the importance of the magnetic sensor 14 or the rate of data change, different priorities are assigned to different magnetic sensors 14. Magnetic sensors 14 with higher priorities receive more sampling opportunities or higher sampling rates. This strategy is suitable when there are critical magnetic sensors 14 in the system.

[0099] Adaptive strategy: The polling order and sampling rate are dynamically adjusted according to changes in system state and environment to adapt to different working conditions. For example, the sampling rate of the magnetic sensor 14 in different areas can be adjusted at different stages of surgery to meet different accuracy requirements.

[0100] In magnetic navigation surgery scenarios, these polling strategies offer the following advantages: Improved real-time performance: Through parallel acquisition and efficient scheduling, data acquisition from all 14 magnetic sensors can be completed in a short time, meeting the real-time requirements of surgical navigation. Improved accuracy: A reasonable sampling strategy can increase the sampling rate and accuracy in critical areas or at critical moments, improving navigation accuracy. Reduced power consumption: By optimizing the sampling strategy and avoiding unnecessary data acquisition, system power consumption is reduced, extending battery life. Improved reliability: Through multi-channel parallel acquisition, even if one channel fails, other channels can still operate normally, improving system reliability and fault tolerance.

[0101] Based on any of the above embodiments, see Figure 7 , Figure 7 This is a schematic diagram of the structure of a magnetic navigation system in one embodiment of this application, as shown below. Figure 7As shown, this embodiment provides a magnetic navigation system 100, including a processor 2, a magnetic field generator 3, and a magnetic navigation positioning terminal 1 as described in any of the above embodiments; the magnetic field generator 3 is used to generate a magnetic field when placed in the surgical environment; the magnetic navigation positioning terminal 1 is used to be attached to the patient's body surface; the processor 2 is used to be electrically connected to the magnetic field generator 3 and the magnetic navigation positioning terminal 1.

[0102] The magnetic navigation system 100 in this embodiment is a complete medical navigation system, including three main parts: processor 2, magnetic field generator 3, and magnetic navigation positioning terminal 1, which is used to provide accurate spatial positioning and navigation functions during surgery.

[0103] Processor 2 is the computing and control center of the entire system, typically a high-performance computer or a dedicated navigation workstation. Processor 2 includes a powerful central processing unit, graphics processing unit, large-capacity memory and storage devices, runs dedicated navigation software, and is responsible for data processing, image reconstruction, registration calculation, and navigation display. Magnetic field generator 3 is a device that generates a spatial magnetic field. It typically consists of multiple coils, generating a known magnetic field distribution in the surgical area by controlling the current in the coils, or it consists of rotatable permanent magnets, generating a known magnetic field distribution in the surgical area by rotating the permanent magnets. Magnetic field generator 3 can be fixed, installed on the ceiling or wall of the operating room; or it can be mobile, placed next to the operating table or under the patient. Magnetic navigation positioning terminal 1 is a device attached to the patient's body surface, containing multiple magnetic sensor clusters 10 for collecting magnetic field information. Magnetic navigation positioning terminal 1 wirelessly transmits the collected magnetic field information to processor 2 for calculating the position and orientation of the magnetic sensors 14 in the magnetic field.

[0104] Based on any of the above embodiments, the processor 2 is further configured to: acquire medical images of a patient with the magnetic navigation positioning terminal 1 attached, and determine the image coordinates of multiple voxel points included in the target area based on the medical images; acquire the state information of the magnetic field generated by the magnetic field generator 3 and the magnetic field information collected by the magnetic sensor 14, and determine the magnetic field coordinates of the magnetic sensor 14 based on the state information and the magnetic field information; and acquire the spatial transformation relationship between the image coordinate system and the magnetic field coordinate system based on the image coordinates and the magnetic field coordinates.

[0105] Specifically, the entire magnetic navigation system 100 operates as follows:

[0106] System initialization: Power on processor 2, magnetic field generator 3 and magnetic navigation and positioning terminal 1, establish communication connection between the three, and perform system self-test and calibration.

[0107] Image acquisition: The patient is scanned using medical imaging equipment such as CT or MR to obtain three-dimensional medical image data. Of course, in other embodiments, the magnetic navigation positioning terminal 1 can be attached to an appropriate position on the patient's body surface first, ensuring that the magnetic sensor 14 can cover the surgical area, and then the patient with the magnetic navigation positioning terminal 1 attached is scanned.

[0108] Image Registration: For images that do not contain the magnetic navigation positioning terminal 1, the processor 2 calculates the coordinates of the magnetic sensor 14 in the magnetic field coordinate system based on the image coordinates of multiple voxel points within the patient's location in the medical image, and then calculates the coordinates of the magnetic sensor 14 in the magnetic field coordinate system based on the magnetic field information collected by the magnetic sensor 14. Finally, it establishes a spatial transformation relationship between the image coordinate system and the magnetic field coordinate system. For images that contain the magnetic navigation positioning terminal 1, the processor 2 calculates the coordinates of the magnetic sensor 14 in the image coordinate system based on the position of the imaging element 15 in the medical image, and then calculates the coordinates of the magnetic sensor 14 in the magnetic field coordinate system based on the magnetic field information collected by the magnetic sensor 14. Finally, it establishes a spatial transformation relationship between the image coordinate system and the magnetic field coordinate system.

[0109] Surgical navigation: During the operation, the magnetic navigation and positioning terminal 1 collects magnetic field information in real time. The processor 2 calculates the position and orientation of the magnetic sensor 14 based on this information, and then maps this position information onto the medical image through spatial transformation relationship to achieve real-time navigation and positioning.

[0110] During surgical navigation, processor 2 can display multiple views, such as axial, sagittal, coronal, and 3D reconstructed views, to help surgeons understand the positional relationship of surgical instruments relative to the patient's anatomy. Processor 2 can also provide functions such as path planning, safety zone marking, and warning prompts, improving the safety and precision of the surgery.

[0111] In summary, the magnetic sensor cluster, magnetic navigation positioning terminal, and magnetic navigation system, by integrating the magnetic sensors and imaging elements onto a rigid PCB and optimizing their layout design, make the imaging elements easier to identify in CT / MR images, thereby improving the accuracy of sensor position extraction and reducing manual selection errors. The use of wireless communication avoids problems such as marker displacement, patch detachment, or cable breakage caused by cable entanglement, improving registration accuracy and operational convenience. The system uses a control unit to control and acquire data from the sensor cluster, offering greater scalability and theoretically allowing connection of clusters containing countless sensors without hardware modifications. Placing the sensor modules on a flexible FPCB creates a flexible sensor cluster that can adapt to more object surfaces without obstruction, further improving registration accuracy. By designing cluster templates of different types and specifications, doctors can select clusters of different sizes based on different body parts and patient characteristics to achieve optimal registration results. The symmetrical device arrangement structure facilitates the formation of fixed patterns, which is beneficial for human visual recognition and also facilitates training machine learning methods for automatic recognition.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A magnetic sensor cluster (10), characterized by It includes multiple magnetic sensor modules (11), each of the magnetic sensor modules (11) includes a first printed circuit board, the first printed circuit board includes a rigid substrate (13), and a magnetic sensor (14) and multiple developing elements (15) disposed on the rigid substrate (13), the multiple developing elements (15) being electronic components in the peripheral circuit of the magnetic sensor (14).

2. The magnetic sensor cluster (10) of claim 1, characterized in that The plurality of developing elements (15) are arranged around the periphery of the magnetic sensor (14), or the plurality of developing elements (15) are arranged on one side of the magnetic sensor (14).

3. The magnetic sensor cluster (10) of claim 2, characterized in that The number of developing elements (15) is two, and the two developing elements (15) are respectively arranged on both sides of the magnetic sensor (14), and the center of the magnetic sensor (14) is located at the midpoint of the line connecting the two developing elements (15).

4. The magnetic sensor cluster (10) of claim 2, characterized in that The developing element (15) is a capacitor.

5. The magnetic sensor cluster (10) of claim 1, characterized in that It also includes a second printed circuit board, which includes a flexible substrate (17) on which a plurality of the magnetic sensor modules (11) are disposed.

6. The magnetic sensor cluster (10) of claim 5, characterized in that The flexible substrate (17) has a straight or arc shape.

7. The magnetic sensor cluster (10) of claim 5, characterized in that The rigid substrate (13) is made of epoxy resin glass fiber, and / or the flexible substrate (17) is made of polyimide.

8. The magnetic sensor cluster (10) of claim 5, characterized in that It also includes a fixing component connected to the second printed circuit board for fixing the second printed circuit board to the patient's body surface.

9. A magnetic navigation positioning terminal (1), characterized by The magnetic sensor cluster (10) includes any one of claims 1-8, and further includes a control unit (20) and a wireless communication unit (30). The control unit (20) is used to supply power to the magnetic sensors (14) in the magnetic sensor cluster (10) and to acquire the magnetic field information collected by the magnetic sensors (14). The wireless communication unit (30) is used to wirelessly transmit the magnetic field information.

10. A magnetic navigation system (100), characterized by It includes a processor (2), a magnetic field generator (3), and the magnetic navigation and positioning terminal (1) as described in claim 9; The magnetic field generator (3) is used to generate a magnetic field in the surgical environment; The magnetic navigation positioning terminal (1) is used to be attached to the patient's body surface; The processor (2) is used to be electrically connected to the magnetic field transmitter and the magnetic navigation and positioning terminal (1).

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