Method and apparatus for magnetoelectrically combined positioning and tracking

Abstract

The present application relates to the field of magnetoelectric combined medical positioning navigation, and particularly relates to a method and device for magnetoelectric combined positioning and tracking, comprising a magnetic field positioning module, an electric field positioning module and a magnetoelectric matching positioning module, the magnetoelectric matching positioning module is configured to obtain magnetic field position data of a magnetic sensor based on the magnetic field positioning module for a positioning space, establish a matching relationship with electric field impedance data obtained by the electric field positioning module, and calibrate electric field positioning through the matching relationship; the specific matching method comprises dividing a cell in the positioning space, recording magnetic field position data and electric field impedance data corresponding to a space point position, calculating the matching relationship of the cell, and finally obtaining a calibrated electric field positioning result through operation by using the matching relationship of the cell; the present application solves the problem of electric field nonlinear positioning and improves the accuracy of electric field positioning.

Description

Technical Field

[0001] This invention relates to the field of magnetic and electric combined medical positioning and navigation, and in particular to a method and apparatus for magnetic and electric combined positioning and tracking. Background Technology

[0002] Current medical positioning and navigation systems include impedance-based positioning systems that consist of one or more pairs of body surface electrodes (e.g., patches) attached outside the patient's body, a reference sensor (e.g., another patch) attached to the patient's body, and one or more sensors (e.g., electrodes) attached to a medical device. Positioning is determined by applying a current to the electrode pairs, measuring the corresponding voltage induced at the device electrodes (i.e., relative to the reference sensor), and processing the measured voltage.

[0003] Magnetic field-based positioning systems typically include one or more magnetic field generators placed near the patient bed or other components of the operating environment, and one or more magnetic field detection coils coupled to a medical device. The generators are coupled to the medical device, and the detection coils may be attached to or placed near components of the operating environment. The generators provide a magnetic field in the anatomical region, the detection coils generate induced signals, and the system processes these signals to generate one or more positioning information associated with the coils. Unlike impedance-based systems, where the coordinate system is relative to the patient with applied body surface electrodes, magnetic field-based systems have a patient-independent coordinate system.

[0004] Both impedance-based and magnetic field-based positioning systems offer advantages. For example, impedance-based systems provide the ability to simultaneously locate a relatively large number of sensors across multiple medical devices. However, because impedance-based systems utilize the flow of electric current in the body, such systems can be susceptible to electrical interference, causing distortion in the geometry and representation of the position measurements relative to the actual image of the examined area. On the other hand, magnetic field-based coordinate systems are independent of the characteristics of the patient's anatomy and generally offer improved accuracy. However, magnetic field-based positioning systems are typically limited to tracking a relatively small number of sensors. Summary of the Invention

[0005] The purpose of this invention is to address the problem of inaccurate position measurement caused by electrical interference in existing electric field-based positioning systems, and to provide a magnetoelectric combined positioning and tracking device and method.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A magnetoelectric positioning and tracking device includes a magnetic field positioning module, an electric field positioning module, and a magnetoelectric matching positioning module.

[0008] The magnetoelectric matching positioning module is configured to divide the positioning space into cells during the phase of establishing magnetoelectric matching relationships. Based on the magnetic field positioning module, magnetic field position data is obtained, and electric field impedance data is obtained from the electric field positioning module to establish matching relationships within each cell. During the electric field calibration phase, the electric field positioning module determines the cell position of the measurement object, and the matching relationship within that cell is used to calibrate its electric field positioning.

[0009] As a preferred embodiment of the present invention, a magnetoelectric combined positioning and tracking method includes:

[0010] Magnetic field positioning, acquiring magnetic field position data, including the spatial position and placement angle of the magnetic sensor;

[0011] Electric field localization, obtaining electric field impedance data;

[0012] Establish matching relationships, divide the positioning space into cells, record the magnetic field position data and electric field impedance data of the spatial points passing through each cell, and calculate the matching relationship of each cell respectively.

[0013] The electric field localization is calibrated by using the matching relationship of cells to calibrate the electric field impedance data collected in the cell, and obtain the calibrated electric field localization result.

[0014] As a preferred embodiment of the present invention, a magnetoelectric combined positioning and tracking method is provided, which uses the Biot-Savart law to obtain the magnetic field position data.

[0015] As a preferred embodiment of the present invention, a magnetoelectric combined positioning and tracking method is provided, wherein the magnetic field position data calculation formula is as follows:

[0016]

[0017]

[0018]

[0019]

[0020] Vol i =γ*(B (x,i) *cos(α)*cos(β)+B (y,i) *cos(α)*sin(β)+B (z,i) *sin(α))

[0021] Among them, the direction vector of the magnetic field generator (x i ,y i ,z i(x, y, z) represents the three-dimensional spatial position, i ≥ 6; (α, β) represents the three-dimensional spatial position of the magnetic sensor, (α, β) represents the polar angle and azimuth angle of the magnetic sensor, and γ is the gain coefficient; Vol i Generate the signal quantity generated by the magnetic field generated by the i-th magnetic field generator acting on the magnetic sensor.

[0022] As a preferred embodiment of the present invention, a magnetoelectric combined positioning and tracking method employs the LM algorithm to solve for the spatial position and placement angle of the magnetic sensor.

[0023] As a preferred embodiment of the present invention, a magnetoelectric combined positioning and tracking method, wherein electric field positioning further includes the following steps:

[0024] Step S1: Obtain the position information of the electrode plates through the magnetic sensors on the electrode plates, select the optimal electrode plates as common ground electrode plates, and record them in the system. The optimal selection and evaluation method is expressed as follows:

[0025]

[0026] Where f(n) represents the selection of the nth electrode as the common ground electrode, n=1,2,3,4,5,6; α, β, γ, μ are weighting coefficients; The unit vector of the line connecting the k-th electrode and the common-ground electrode. The unit vector connecting the t-th electrode and the common-ground electrode. The dot product result; Dis(n,k) is the distance between the k-th electrode and the common ground electrode; V Ang express and The variance of the set is formed by the included angles between the elements, k∈1,2,3,4,5,6, t∈1,2,3,4,5,6, k≠n, t≠n, k≠t; V Dis This represents the variance of the distance set between the remaining electrode plates and the common ground electrode plate;

[0027] Step S2: Select three electrode plates that are orthogonal to the common ground electrode plate and record them in the system. The selection and evaluation method is expressed as follows:

[0028]

[0029] Where, n best This is the number of the common ground electrode plate. express and The dot product result is given by three orthogonal electrode plates a, b, and c, satisfying a∈1,2,3,4,5,6, b∈1,2,3,4,5,6, c∈1,2,3,4,5,6, and a≠b≠c≠n. best ;

[0030] In step S3, the remaining electrode patches are excited relative to the common ground electrode patch using a frequency division or time division method, and the electric field impedance data of the interventional catheter electrodes relative to the electrode patches are collected.

[0031] As a preferred embodiment of the present invention, a magnetoelectric combined positioning and tracking method includes the following matching relationships:

[0032] A linear matching relationship is established using the electric field impedance data collected by the orthogonal electrode array (a, b, c):

[0033]

[0034] A nonlinear matching relationship is established using the electric field impedance data collected by the orthogonal electrode group (a,b,c):

[0035]

[0036] A linear matching relationship is established using the electric field impedance data at two locations or two times (m, n) collected by the orthogonal electrode array (a, b, c):

[0037]

[0038] A linear matching relationship is established using the electric field impedance data collected under all excitations:

[0039]

[0040] A nonlinear matching relationship is established using the electric field impedance data collected under all excitations:

[0041]

[0042] A linear matching relationship is established using the electric field impedance data collected at two locations or two times (m, n) under all excitations:

[0043]

[0044] As a preferred embodiment of the present invention, a magnetoelectric combined positioning and tracking method directly outputs the electric field positioning result after calibration using a matching relationship, or outputs the electric field positioning result after weighted combination processing. The expression for the weighted combination processing is as follows:

[0045] Out = Coef 1 *Out 1 +Coef 2 *Out 2 +Coef 3 *Out 3 +Coef 4 *Out 4+Coef 5 *Out 5 +Coef 6 *Out 6

[0046] Among them, Out 1 Out 2 Out 3 Out 4 Out 5 Out 6 The electric field localization results after calibration for matching relationships (1), (2), (3), (4), (5), and (6) are respectively; Coef 1 Coef 2 Coef 3 Coef 4 Coef 5 Coef 6 The electric field location results are as follows: Out 1 Out 2 Out 3 Out 4 Out 5 Out 6 The weighting coefficients.

[0047] As a preferred embodiment of the present invention, a magnetoelectric combined positioning and tracking method is provided, wherein the spacing between spatial points within a cell is not less than 0.5 mm.

[0048] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows: by dividing the positioning space into cells, collecting electric field impedance data and magnetic field position data, calculating the matching relationship between the electric field impedance data and magnetic field position data in each cell, and then correcting the electric field positioning in the corresponding cell, the accuracy of electric field positioning is effectively improved. At the same time, using the matching relationship in each cell to calibrate the electric field positioning in the corresponding cell also improves the accuracy of electric field positioning calibration. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the system device of the present invention.

[0050] Figure 2 This is a schematic diagram of a magnetic field generator.

[0051] Figure 3 This is a schematic diagram of magnetic sensor positioning.

[0052] Figure 4 This is a schematic diagram of electric field positioning.

[0053] Figure 5This is a schematic diagram of the matching relationship between the magnetic field and the electric field.

[0054] Icons: 101-Patient; 102-Electrode pad; 103-Interventional catheter; 104-Control handle; 105-Magnetic field drive device; 106-Magnetic field generator; 107-Electric field drive device; 108-Hub; 109-Magnetic field positioning solution module; 110-Positioning box; 111-Electric field positioning solution module; 112-Magnetic-electric matching positioning module; 104-Control handle; 104-Control handle; 104-Control handle; 104-Control handle; 104-Control handle; 104-Control handle; 104-Control handle. Detailed Implementation

[0055] The present invention will now be described in detail with reference to the accompanying drawings.

[0056] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0057] Example 1

[0058] like Figure 1 As shown, a magnetoelectric combined positioning and tracking device includes a magnetic field positioning module, an electric field positioning module, and a magnetoelectric matching positioning module 112. 100 is a schematic diagram of the system, which is equipped with an interventional catheter 103. A magnetic sensor and an electric sensor are installed at the distal end of the interventional catheter 103. 104 is the control handle of the interventional catheter 103, and 101 is the patient. The positioning box 110 can be connected to multiple magnetic field information acquisition sensors or electric field information acquisition sensors.

[0059] The magnetoelectric matching positioning module 112 is configured to divide the positioning space into cells during the stage of establishing magnetoelectric matching relationship, obtain magnetic field position data based on the magnetic field positioning module, obtain electric field impedance data with the electric field positioning module, and establish matching relationship within each cell; during the electric field calibration stage, determine the cell position of the measurement object through the electric field positioning module, and calibrate its electric field positioning using the matching relationship within the cell.

[0060] The magnetic field positioning module includes a magnetic field driving device 105, a magnetic field generator 106, and a magnetic field positioning solution module 109. The magnetic field driving device 105 is connected to the magnetic field generator 106 and drives the magnetic field generator 106 to generate a magnetic field. The magnetic field positioning solution module 109 is used to obtain the magnetic field position data of the magnetic sensor.

[0061] Specifically, the magnetic field generator 106 includes at least six magnetic field generators, which can be arranged in groups or distributed. For example... Figure 2The diagram shows the group arrangement of the magnetic field generators. Groups 202A, 202B, 202C, and 202D are magnetic field generator groups. Each group includes three magnetic field generators. For example, group 202A includes three magnetic field generators: 205, 206, and 207. Their positions are approximately orthogonal to each other.

[0062] The electric field positioning module includes an electrode sheet 102, an electric field driving device 107, and an electric field positioning solution module 111, such as... Figure 4 As shown, electrode 102, including 401, 402, 403, 404, 405, and 406, is applied to the body surface of the intervention object 101 to apply an excitation electrical signal. Electrode 102 is connected to electric field driving device 107 via hub 108. Electric field driving device 107 applies a constant current or constant voltage electrical signal to the electrode 101 for excitation. Electric field positioning solution module 111 is used to obtain electric field impedance data.

[0063] A method for positioning and tracking using a combination of magnetoelectric and electromagnetic methods includes:

[0064] Magnetic field positioning: The magnetic field driving device 105 drives the magnetic field generator 106 to generate an alternating magnetic field, which acts on the magnetic sensor. The magnetic field position data, including the spatial position and placement angle of the magnetic sensor, is obtained by the magnetic field positioning solution module 109.

[0065] The magnetic sensor is installed at the distal end of the interventional catheter 103. This magnetic sensor is placed inside the patient's body. Common devices with magnetic sensors in the medical field include catheters, guidewires, guides, probes, etc., and their applications include cardiac interventional therapy navigation, pulmonary bronchial positioning navigation, and renal artery ablation navigation.

[0066] Specifically, the magnetic field driving device 105 drives the magnetic field generator in two ways: one is frequency division driving, in which the magnetic field driving device 105 modulates signals of different frequencies for each magnetic field generator to generate an alternating magnetic field. The alternating magnetic field acts on the magnetic sensor to generate an induced current, and the induced voltage is obtained through the magnetic field information acquisition sensor. The induced voltage is demodulated to obtain the voltage of each magnetic field generator acting on the magnetic sensor. The other is time division driving, in which the magnetic field driving device 105 drives each magnetic field generator in a time-division manner, and the corresponding induced voltage on the magnetic sensor is acquired through the magnetic field information acquisition sensor.

[0067] Furthermore, after obtaining the induced voltage generated by each magnetic field generator acting on the magnetic sensor, the spatial position and placement angle P(x,y,z,α,β) of the magnetic sensor can be solved according to the magnetic dipole model.

[0068] Figure 3This is a schematic diagram of the magnetic field positioning and tracking principle. Similarly, 302A, 302B, 302C, and 302D are magnetic field generator groups, each group consisting of 3 magnetic field generators. The position and placement angle P(x) of one of the magnetic field generators are known. i ,y i ,z i ,α i ,β i ), 304 is a magnetic sensor installed at the distal end of interventional catheter 103.

[0069] Because the distance between the magnetic field generator and the magnetic sensor is much larger than the size of the magnetic field generator itself, they can be considered as magnetic dipoles. According to the Biot-Savart law, based on the position of the magnetic field generator 302 and its placement angle P(x)... i ,y i ,z i ,α i ,β i This yields the normalized magnetic field generator direction vector.

[0070] Dir (x,i) =cos(α) i )*cos(β i (1)

[0071] Dir (y,i) =cos(α) i )*sin(β i (2)

[0072] Dir (z,i) =sin(α) i (3)

[0073]

[0074] Among them, (x i ,y i ,z i (α) represents the three-dimensional spatial position of the magnetic field generator 302. i ,β i α represents the placement angle of the magnetic field generator 302, i.e., the pitch angle. i and rotation angle β i , i≥6.

[0075] The distance from the magnetic sensor to the magnetic field generator 302 is:

[0076]

[0077] The i-th magnetic field generator generates a magnetic field that acts on the magnetic sensor, producing a signal quantity Vol. iThe demodulation output result corresponding to electrode 405:

[0078]

[0079]

[0080]

[0081]

[0082] Vol i =γ*(B (x,i) *cos(α)*cos(β)+B (y,i) *cos(α)*sin(β)+B (z,i) *sin(α)) (10)

[0084] Where (x,y,z) represents the three-dimensional spatial position of the magnetic sensor, (α,β) represents the pitch and rotation angles of the magnetic sensor, and γ represents the gain coefficient; since the spatial position and placement angle P(x,y,z,α,β,γ) of the magnetic sensor contain 6 unknowns, and 12 magnetic field generators are set, 12 equations containing 6 unknowns are obtained, which are combined to form an overdetermined system of equations:

[0085]

[0086] To solve overdetermined systems of equations, some or all of the equations can be selected and solved simultaneously according to certain screening criteria. The number of equations in the system should be greater than or equal to six. A commonly used solution method is the Levenberg-Marquardt (LM) algorithm or its improved versions. This patent uses an improved version, which can achieve convergence in approximately 10 iterations. The problem is solved based on a nonlinear model.

[0087] Electric field positioning: The electric field driving device 107 applies an electrical signal to the electrode plate 102 for excitation, and the electric field positioning solution module 111 obtains the electric field impedance data of the electrode of the interventional catheter 103 relative to the electrode plate 102.

[0088] Specifically, such as Figure 4 The diagram shows the electric field localization method. 401, 402, 403, 404, 405, and 406 are patches applied to the surface of the interventional object 101 to apply excitation electrical signals. The electric field localization module includes solving for the optimal excitation delivery method, excitation delivery, and impedance acquisition. The optimal excitation delivery method solution includes solving for the optimal common-ground patch and solving for the approximately most orthogonal patch combination. The method steps are as follows:

[0089] Step S1, optimal common-ground patch solution, aims to select the optimal excitation common-ground electrode patch. The selection principle is to maximize the distance between the other surface patches and the common-ground surface patch, maximize the angle between the lines connecting the two surface patches and the common-ground patch, minimize the difference in distance, and minimize the difference in angle. The position information of the electrode patch is obtained through the magnetic sensor on the electrode patch, and the optimal electrode patch is selected as the common-ground electrode patch, such as... Figure 4 The optimal screening and evaluation method for the common ground electrode 402 is expressed as follows:

[0090]

[0091] Where n = 1, 2, 3, 4, 5, 6, it indicates that the nth surface electrode is selected as the common surface electrode. α, β, γ, and μ are weighting coefficients, describing the included angle, distance, and included angle variance V, respectively. Ang Distance variance V Dis The degree of importance is generally α=β=γ=μ=0.25; The unit vector connecting the k-th electrode and the common-ground electrode n. The unit vector connecting the t-th electrode and the common-ground electrode. The dot product result between them; Dis(n,k) is the distance between the k-th electrode and the common ground electrode n; V Ang express and The variance of the set is formed by the included angles between the elements, k∈1,2,3,4,5,6, t∈1,2,3,4,5,6, k≠n, t≠n, k≠t; V Dis This represents the variance of the distance set between the remaining electrode plates and the common ground electrode plate.

[0092]

[0093] Through the above processing, the optimal common-ground electrode plate number for incentive distribution is obtained as n. best Record it in the system.

[0094] Step S2, solving for the approximately most orthogonal electrode combination, aims to select the three patches that are most orthogonal to the optimal common-ground electrode after determining the optimal common-ground electrode. The selection and evaluation method can be described by the following expression:

[0095]

[0096] Where, n best This is the numbering of the optimal common-ground electrode plate. express and The dot product result, a, b, c, represents three patches selected from the remaining five patches excluding the common ground electrode patch, satisfying a∈1,2,3,4,5,6, b∈1,2,3,4,5,6, c∈1,2,3,4,5,6, and a≠b≠c≠n. best .

[0097] (a,b,c)=argmin f(a,b,c,n best (15)

[0098] Through the above processing, the relative common patch n is obtained. best The most orthogonal electrode combination (a, b, c) is determined and recorded in the system.

[0099] Step S3: Excitation delivery and impedance acquisition. The remaining electrode plates are excited relative to the common ground electrode plate using a frequency division delivery method or a time division delivery method, and the electric field impedance data of the interventional catheter electrodes relative to the electrode plates are acquired.

[0100] Among them, the remaining electrode plates represent the electrode plates other than the common ground electrode plate. The frequency division method is that the remaining 5 electrode plates excite the common ground electrode plate at different frequencies. The time division method is that the common ground electrode plate is excited in turn in turn.

[0101] Furthermore, impedance acquisition includes acquiring the electric field impedance data of the electrodes of the interventional catheter 103 relative to the electrode pads under each pair of excitations; in the frequency division mode, the acquired information needs to be demodulated to obtain the electric field impedance data Ele(v) of the electrodes of the interventional catheter 103 under each pair of excitations. 1 ,v 2 ,v 3 ,v 4 ,v 5 The time-sharing delivery method can directly acquire the electric field impedance data Ele(v) of the 103 electrodes of the interventional catheter under each pair of excitations. 1 ,v 2 ,v 3 ,v 4 ,v 5 ).

[0102] Establish a matching relationship, divide the positioning space into cells, store the spatial points passed by the interventional catheter 103 in each cell, record the magnetic field position data and electric field impedance data corresponding to the spatial point positions in each cell, and calculate the matching relationship of each cell.

[0103] Specifically, such as Figure 5The positioning space is divided into cells, with 501 representing the heart and 502 representing the cell division within the heart chamber space. Cell division can be done using various sizes, with different sizes representing different cell resolutions, such as 2.5×2.5×2.5, 5×5×5, or 10×10×10 (unit: mm). 503 is one of the cells, storing the spatial point positions 504 traversed by the interventional catheter 103. The data acquisition phase begins by determining the cell containing the interventional catheter 103, obtaining the spatial point positions 504 traversed by the catheter within that cell, and recording the magnetic field position data and electric field impedance data corresponding to each spatial point. The data points must satisfy a spatial spacing distribution, meaning the distance between spatial points must be no less than 0.5 mm.

[0104] Secondly, when the number of data points in a cell meets the minimum data requirement for solving the matching relationship, the matching relationship information of that cell is solved and updated. This can be understood as selecting a matching method that can be solved based on the number of data points recorded in each cell, and then solving and updating the matching relationship of that cell. The several methods for establishing magnetic field and electric field matching relationships involved in this invention are described as follows:

[0105] a. Establish a linear matching relationship 1 using information collected from the most orthogonal electrode group, as described below:

[0106]

[0107] b. A nonlinear matching relationship 2 is established using the information collected from the most orthogonal electrode group, as described below:

[0108]

[0109] c. Establish a linear matching relationship 3 using the information from two positions (or two times) m and n acquired by the most orthogonal electrode group, as described below:

[0110]

[0111] d. Establish a linear matching relationship using the impedance information collected under all excitations, as described below:

[0112]

[0113] e. Establish a nonlinear matching relationship using the impedance information collected under all excitations, as described below:

[0114] f. Establish a linear matching relationship using the impedance information of two positions (or two times) m and n acquired under all excitations, as described below:

[0115]

[0116] The electric field localization is calibrated by applying the matching relationship between each cell to calibrate the electric field localization of that cell. Electric field information of the interventional catheter 103 relative to each electrode is collected, and after processing, the electric field impedance data Ele(v) of each electrode under each set of excitations is obtained. 1 ,v 2 ,v 3 ,v 4 ,v 5 ) and the electric field impedance data Ele(v) under the most orthogonal excitation group a ,v b ,v c Locate the cell corresponding to the current electric field impedance data, and use the matching relationship established within that cell to calculate the final calibrated electric field localization result, including the following:

[0117] a. Applying matching relationship 1, the electric field localization result is Out. 1 (x,y,z) is:

[0118] Out 1 (x,y,z)=Ele(v a ,v b ,v c )*R 3x3 (twenty two)

[0119] b. Applying matching relationship 2, the electric field localization result is output. 2 (x,y,z) is:

[0120] Out 2 (x,y,z)=Ele(v a ,v b ,v c ,v a *v a ,v b *v b ,v c *v c )*R 6x3 (twenty three)

[0121] c. Applying matching relationship 3, the electric field localization result is output. 3 (x,y,z) is:

[0122]

[0123] in, or To compare with the currently measured electric field impedance data Ele(v) a ,v b ,vc The most recent historical data recorded in the cell.

[0124] d. Applying matching relation 4, the electric field localization result is output. 4 (x,y,z) is:

[0125] Out 4 (x,y,z)=Ele(v 1 ,v 2 ,v 3 ,v 4 ,v 5 )*R 5x3 (25)

[0126] e. Applying matching relationship 5, the electric field localization result is output. 5 (x,y,z) is:

[0127] Out 5 (x,y,z)=Ele(v 1 ,v 2 ,v 3 ,v 4 ,v 5 ,v 1 *v 1 ,v 2 *v 2 ,v 3 *v 3 ,v 4 *v 4 ,v 5 *v 5 )*R 10x3 (26)

[0128] f. Applying matching relationship 6, the electric field localization result is output. 6 (x,y,z,x0,y0,z0) is:

[0129]

[0130] Where (x0,y0,z0) represents redundant output, which is the calibration result corresponding to the previous position or the previous time step;

[0131]

[0132] or

[0133]

[0134] To compare with the currently measured electric field impedance data

[0135] Ele(v 1 ,v2 ,v 3 ,v 4 ,v 5 The most recent historical data recorded in the cell.

[0136] It should be noted that the above electric field correction results can be directly used as the final calibration result, or they can be obtained by weighted combination processing.

[0137] Out = Coef 1 *Out 1 +Coef 2 *Out 2 +Coef 3 *Out 3 +Coef 4 *Out 4 +Coef 5 *Out 5 +Coef 6 *Out 6 (28)

[0138] Among them, Out 1 Out 2 Out 3 Out 4 Out 5 Out 6 The electric field localization results after calibration for matching relationships (1), (2), (3), (4), (5), and (6) are respectively; Coef 1 Coef 2 Coef 3 Coef 4 Coef 5 Coef 6 The electric field location results are as follows: Out 1 Out 2 Out 3 Out 4 Out 5 Out 6 The weighting coefficients.

[0139] In summary, this invention utilizes magnetic field position data and electric field impedance data collected from the same spatial location to divide the spatial location into cells, establishes a matching relationship between the magnetic field and electric field positions of each cell, and uses the matching relationship to correct the electric field impedance position collected within the corresponding cell, thereby improving the accuracy of electric field positioning calibration, solving the problem of electric field nonlinear positioning, and thus improving the accuracy of electric field positioning.

[0140] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A magnetoelectric positioning and tracking device, characterized in that, It includes a magnetic field positioning module, an electric field positioning module, and a magnetoelectric matching positioning module (112); The magnetoelectric matching positioning module (112) is configured to divide the positioning space into cells during the stage of establishing magnetoelectric matching relationship, obtain magnetic field position data based on the magnetic field positioning module, and obtain electric field impedance data based on the electric field positioning module, and establish matching relationship within each cell. During the electric field calibration stage, the cell location of the measurement object is determined by the electric field positioning module, and its electric field positioning is calibrated using the matching relationship within that cell. The matching relationships include: A linear matching relationship was established using the electric field impedance data collected by the orthogonal electrode group (a,b,c) (1): A nonlinear matching relationship was established using the electric field impedance data collected by the orthogonal electrode group (a,b,c): A linear matching relationship is established using the electric field impedance data at two locations or at two times (m, n) collected by the orthogonal electrode group (a, b, c): A linear matching relationship was established using the electric field impedance data collected under all excitations (4): A nonlinear matching relationship was established using the electric field impedance data collected under all excitations (5): A linear matching relationship is established using the electric field impedance data collected at two locations or at two times (m, n) under all excitations (6): After calibration using the aforementioned matching relationship and subsequent weighted combination processing, the output electric field localization result is determined. The expression for the weighted combination processing is as follows: in, The electric field localization after calibration for matching relationships (1), (2), (3), (4), (5), and (6) are respectively. result; Electric field location results Weighting coefficients; The electric field localization also includes the following steps: Step S1: Select the optimal electrode sheet as the common ground electrode sheet and record it in the system. The optimal selection and evaluation method is expressed as follows: Where f(n) represents the selection of the nth electrode as the common ground electrode, n=1,2,3,4,5,6; α, β, γ, μ are weighting coefficients; The unit vector of the line connecting the k-th electrode and the common-ground electrode. The unit vector connecting the t-th electrode and the common-ground electrode. The dot product result; Dis(n,k) is the distance between the k-th electrode and the common ground electrode; V Ang express and The variance of the set is formed by the angles between the given elements, k∈1,2,3,4,5,6, t∈1,2,3,4,5,6, k≠n, t≠n, k≠t; V Dis This represents the variance of the distance set between the remaining electrode plates and the common ground electrode plate; Step S2: Select three electrode plates orthogonal to the common ground electrode plate and record them in the system. The selection and evaluation method is expressed as follows: Where, n best This is the number of the common ground electrode plate. express and The dot product result is that a, b, c are three orthogonal electrode plates, satisfying a∈1,2,3,4,5,6, b∈1,2,3,4,5,6, c∈1,2,3,4,5,6, and a≠b≠c≠nbest; Step S3: Excite the remaining electrode plates relative to the common ground electrode plate and collect the electric field impedance data of the electrodes of the interventional catheter relative to the electrode plates. The spacing between spatial points within a cell shall not be less than 0.5 mm.

2. A method for a magnetoelectric combined positioning and tracking device, characterized in that, include: Magnetic field positioning, acquiring magnetic field position data, including the spatial position and placement angle of the magnetic sensor; Electric field localization, obtaining electric field impedance data; Establish matching relationships, divide the positioning space into cells, record the magnetic field position data and electric field impedance data of the spatial points passing through each cell, and calculate the matching relationship of each cell respectively. The electric field localization is calibrated by using the matching relationship of cells to calibrate the electric field impedance data collected in the cell and obtain the calibrated electric field localization result. The matching relationships include: A linear matching relationship was established using the electric field impedance data collected by the orthogonal electrode group (a, b, c): A nonlinear matching relationship was established using the electric field impedance data collected by the orthogonal electrode group (a, b, c): A linear matching relationship is established using electric field impedance data collected at two locations or at two times (m, n) by orthogonal electrode groups (a, b, c): A linear matching relationship was established using the electric field impedance data collected under all excitations (4): A nonlinear matching relationship was established using the electric field impedance data collected under all excitations (5): A linear matching relationship is established using the electric field impedance data collected at two locations or at two times (m, n) under all excitations (6): The electric field positioning result can be directly output after calibration using the matching relationship, or it can be output after weighted combination processing. The expression for weighted combination processing is: in, The electric field localization after calibration for matching relationships (1), (2), (3), (4), (5), and (6) are respectively. result; Electric field location results Weighting coefficients; The electric field localization also includes the following steps: Step S1: Select the optimal electrode sheet as the common ground electrode sheet and record it in the system. The optimal selection and evaluation method is expressed as follows: Where f(n) represents the selection of the nth electrode as the common ground electrode, n=1,2,3,4,5,6; α, β, γ, μ are weighting coefficients; The unit vector of the line connecting the k-th electrode and the common-ground electrode. The unit vector connecting the t-th electrode and the common-ground electrode. The dot product result; Dis(n,k) is the distance between the k-th electrode and the common ground electrode; V Ang express and The variance of the set is formed by the included angles between the elements, k∈ 1,2,3,4,5,6, t∈1,2,3,4,5,6, k≠n, t≠n, k≠t; V Dis This represents the variance of the distance set between the remaining electrode plates and the common ground electrode plate; Step S2: Select three electrode plates orthogonal to the common ground electrode plate and record them in the system. The selection and evaluation method is expressed as follows: Where, n best This is the number of the common ground electrode plate. express and The dot product result is that a, b, c are three orthogonal electrode plates, satisfying a ∈ 1,2,3,4,5,6, b ∈ 1,2,3,4,5,6, c ∈ 1,2,3,4,5,6, and a ≠ b ≠ c ≠ ​​nbest; Step S3: Excite the remaining electrode plates relative to the common ground electrode plate and collect the electric field impedance data of the electrodes of the interventional catheter relative to the electrode plates. The spacing between spatial points within a cell shall not be less than 0.5 mm.

3. The method of a magnetoelectric combined positioning and tracking device according to claim 2, characterized in that, The magnetic field position data are obtained using the Biot-Savart law.

4. The method of a magnetoelectric combined positioning and tracking device according to claim 2, characterized in that, The formula for calculating the magnetic field position data is as follows: Among them, the direction vector of the magnetic field generator , For three-dimensional space The position of the magnetic sensor is i≥6; (x, y,z) is the three-dimensional spatial position of the magnetic sensor, (α,β) is the polar angle and azimuth angle of the magnetic sensor, and γ is the gain coefficient; Generate the signal quantity generated by the magnetic field generated by the i-th magnetic field generator acting on the magnetic sensor.

5. The method of a magnetoelectric combined positioning and tracking device according to claim 2, characterized in that, The LM algorithm is used to solve for the spatial position and placement angle of the magnetic sensor.

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