Positioning system, method, interventional surgery system, electronic device and storage medium

Abstract

The present invention provides a positioning system, method, interventional surgery system, electronic device and storage medium for an interventional device, wherein the positioning system includes a magnetic field generating unit, an excitation control unit, a data acquisition unit and a controller. The present invention divides a target area into multiple sub-areas, and uses a learning device in a fitting stage to obtain a fitting model for each sub-area for describing the mapping relationship between voltage and distance. Then, in the positioning stage, the distance between a third site on the application device and an electrode patch is obtained based on the fitting model of the sub-area where the application device is located, and the position of the third site can be obtained according to the distance between the third site and the electrode patch and the spatial position information of the electrode patch. The present invention divides the target area into multiple sub-areas, and establishes a fitting model for each sub-area respectively. Since the electric field is linear in a small local range, these fitting models can be used to more accurately achieve positioning calculations.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a positioning system and method for an interventional device, an interventional surgery system, an electronic device and a storage medium. Background Art

[0002] In many medical application scenarios, it is necessary to determine the exact position of various medical devices such as catheters and implants in the body. A variety of positioning systems have been developed in current medical equipment. Generally, various energy fields, such as magnetic fields, electric fields or ultrasonic fields, are applied outside the body, and sensors that can sense the corresponding energy fields, such as magnetic field sensors, electric field sensors and ultrasonic transducers, are installed on the device to be positioned inside the body, and then the energy field information sensed by the sensor is converted into spatial position information. Among them, the magnetic field-based positioning system is relatively mature and has high accuracy; however, there is a disadvantage that the magnetic field sensor is expensive and not suitable for large-scale use. Therefore, magnetic field positioning is generally used in combination with other positioning technologies to control costs while ensuring sufficient positioning accuracy.

[0003] There are three positioning methods in the prior art:

[0004] 1. Place several patch electrodes on the body surface, use the electrodes on the catheter in the body to emit current excitation, measure the impedance value between the catheter electrode and each patch on the body surface, and the magnetic field sensor installed on the catheter will provide accurate spatial position information; after calculating the conversion relationship between the impedance values ​​of multiple positions and the corresponding positions, the positioning and tracking can be achieved only by the impedance value at the common electrode.

[0005] 2. The first and second coordinate systems are defined based on the electric field and the magnetic field, respectively. The magnetic field sensor on the catheter is close to the electrode. After the position of the magnetic field sensor in the first coordinate system is associated with the position of the magnetic field sensor in the second coordinate system using a mapping function, the position of the electrode is adjusted and calibrated accordingly based on the mapping position of the magnetic field sensor in the first coordinate system.

[0006] 3. Apply three mutually orthogonal signals to the area of ​​interest of the human body, measure the voltage between the electrode on the catheter in the body and the reference electrode, and use three voltages in three orthogonal directions (i.e., xyz directions) to calculate the position coordinates of the catheter electrode.

[0007] However, the accuracy of the above-mentioned electromagnetic field positioning methods is not high enough. This is because the distribution of various substances in the body is uneven, and the electric field will be nonlinearly distorted in the body. This distortion makes it difficult to accurately model the electric field distribution in the body using existing linear models, which in turn leads to inaccurate positioning results. Summary of the invention

[0008] The purpose of the present invention is to provide an interventional device positioning system, method, interventional surgery system, electronic device and storage medium, which can locate and track the interventional device in the target object, reduce the calculation amount of positioning, and save time cost.

[0009] To achieve the above object, the present invention provides a positioning system for an interventional device, wherein the interventional device comprises a learning tool and an application tool, wherein the learning tool and the application tool are used to be placed in a target area of ​​a target object;

[0010] The positioning system comprises: a magnetic field generating unit, an excitation control unit, a data acquisition unit and a controller;

[0011] The magnetic field generating unit is used to generate a magnetic field passing through the target object;

[0012] The excitation control unit is used to generate an N-axis electric field in the target object by applying excitation between at least three electrode patches arranged on the surface of the target object, where N≥3;

[0013] The controller is used to divide the target area into a plurality of sub-areas;

[0014] The data acquisition unit is used to synchronously acquire the magnetic field strength information of the first point on the learning device, the magnetic field strength information at the electrode patch, and the voltage information of the second point on the learning device relative to a reference position under all excitation states in each of the sub-areas during the fitting phase; and synchronously acquire the magnetic field strength information at the electrode patch and the voltage information of the third point on the application device relative to the reference position under all excitation states during the positioning phase;

[0015] The controller is also used to calculate the spatial position information of the second site in each of the sub-regions in a fitting stage based on the magnetic field strength information of the first site and the spatial distance information between the first site and the second site, and obtain a fitting model for each of the sub-regions for describing the mapping relationship between voltage and distance based on the voltage information of the second site relative to the reference site under different excitation states and the distance information between the second site and the electrode patch; and, in a positioning stage, calculate the spatial position information of the third site based on the voltage information of the third site relative to the reference site under different excitation states and the sub-region information where the application device is located, using the fitting model of the corresponding sub-region and the spatial position information of the electrode patch, wherein the spatial position information of the electrode patch is calculated based on the magnetic field strength information at the electrode patch.

[0016] Optionally, the controller is used to combine the voltage information of the second site relative to the reference position under different excitation states and the distance information between the second site and the electrode patch into a first type of voltage-distance data pair, and perform fitting to obtain a fitting model for describing the mapping relationship between voltage and distance under different excitation states in each of the sub-areas.

[0017] Optionally, the controller is used to calculate the distance information between the third site and at least three of the electrode patches using the fitting model under different excitation states in the corresponding sub-area, and calculate the spatial position information of the third site based on the distance information between the third site and the at least three electrode patches and the spatial position information of the at least three electrode patches.

[0018] Optionally, the controller is used to, in a fitting stage, for each of the electrode patches, compose a first type of voltage-distance data pair with voltage information of the second site relative to the reference site under different excitation states associated with the electrode patch and distance information between the second site and the electrode patch, and perform fitting to obtain a fitting model for each of the electrode patches under different excitation states associated with the electrode patch in each of the sub-regions; and

[0019] In the positioning stage, the distance information between the third site and the electrode patch is calculated using the fitting model corresponding to the electrode patch in the sub-region where the application device is located.

[0020] Optionally, the controller is used to select a fitting model that meets a first preset condition from all fitting models corresponding to the electrode patch under different excitation states related to it as a target fitting model, and calculate the distance information between the third site and the electrode patch based on the target fitting model.

[0021] Optionally, the controller is used to select at least three electrode patches that meet the second preset condition from all the electrode patches as target electrode patches, use the fitting model of the sub-area where the application device is located to calculate the distance information between the third site and each of the target electrode patches, and calculate the spatial position information of the third site based on the spatial position information of each of the target electrode patches.

[0022] Optionally, the application device further includes a fourth site;

[0023] The data acquisition unit is also used to synchronously acquire the magnetic field strength information of the fourth position during the positioning stage;

[0024] The controller is also used to calculate the spatial position and direction information of the fourth position according to the magnetic field strength information of the fourth position during the positioning stage, and obtain the sub-area information where the application device is located according to the spatial position and direction information of the fourth position.

[0025] Optionally, the application device is further provided with a fifth site;

[0026] The data acquisition unit is also used to synchronously acquire voltage information of the fifth position relative to the reference position under all excitation states during the positioning stage;

[0027] The controller is also used to calculate the spatial position information of the fifth site according to the spatial position and direction information of the fourth site and the spatial distance information between the fourth site and the fifth site during the positioning stage, and calculate the distance information between the fifth site and the electrode patch according to the spatial position information of the fifth site and the spatial position information of the electrode patch, and to form a second type of voltage-distance data pair by combining the voltage information of the fifth site relative to the reference position under different excitation states and the distance information between the fifth site and the electrode patch, and use the second type of voltage-distance data pair to update the fitting model of the corresponding sub-area.

[0028] Optionally, the learning tool and the application tool are the same tool, the fourth site and the first site are the same site, and the fifth site and the second site are the same site.

[0029] Optionally, the controller is also used to combine the voltage information of the third site relative to the reference position under different excitation states and the distance information between the third site and the electrode patch into a third type of voltage-distance data pair, and to filter out valid data pairs from the third type of voltage-distance data pairs, and use the valid data pairs to update the fitting model of the corresponding sub-area.

[0030] Optionally, the excitation control unit is used to apply excitation between the at least three electrode patches and perform continuous and cyclic high-speed switching between all excitation states, and the data acquisition unit collects voltage information of the second site and the third site relative to the reference position under all excitation states; or

[0031] The excitation control unit is used to apply excitation between the at least three electrode patches simultaneously, but the frequencies of the applied excitations are different from each other, and the data acquisition unit collects the voltage information of the second site and the third site relative to the reference site and performs filtering processing to obtain the voltage information of the second site and the third site relative to the reference site under all excitation states; or

[0032] The excitation control unit is used to apply excitation between the at least three electrode patches at the same time, but the frequencies of the applied excitation are different. The data acquisition unit collects voltage information of the second site and the third site relative to the reference position. The controller is used to filter the voltage information of the second site and the third site relative to the reference position collected by the data acquisition unit to obtain the voltage information of the second site and the third site relative to the reference position under all excitation states.

[0033] Optionally, the positioning system also includes a communication control unit, which is used to connect the controller and the magnetic field generating unit, the excitation control unit, and the data acquisition unit to control the communication and data transmission between the controller and the magnetic field generating unit, the excitation control unit, and the data acquisition unit.

[0034] Optionally, the positioning system further comprises a display unit communicatively connected to the controller, wherein the display unit is used to display the position, direction, shape and / or motion trajectory of the learning tool and / or the application tool in the target object.

[0035] Optionally, a first magnetic field sensor is provided at the first site, and a second magnetic field sensor is provided on the electrode patch, and the data acquisition unit acquires magnetic field intensity information at the first site through the first magnetic field sensor, and acquires magnetic field intensity information at the electrode patch through the second magnetic field sensor;

[0036] The second site is provided with a first voltage sensor, and the third site is provided with a second voltage sensor. The data acquisition unit acquires voltage information of the second site relative to the reference site through the first voltage sensor, and acquires voltage information of the third site relative to the reference site through the second voltage sensor.

[0037] In order to achieve the above-mentioned object, the present invention further provides an interventional surgery system, comprising the positioning system of the interventional device described above and the interventional device.

[0038] To achieve the above object, the present invention further provides a method for positioning an interventional device, wherein the interventional device includes a learning tool and an application tool, wherein the learning tool and the application tool are used to be placed in a target area of ​​a target object, and the positioning method includes:

[0039] Dividing the target area into a plurality of sub-areas;

[0040] In the fitting stage, the magnetic field strength information of the first point on the learning device synchronously collected in each of the sub-areas, the magnetic field strength information at at least three electrode patches set on the surface of the target object, and the voltage information of the second point on the learning device relative to a reference position under all excitation states are obtained; the spatial position information of the second point is calculated according to the magnetic field strength information of the first point and the spatial distance information between the first point and the second point; and the fitting model for describing the mapping relationship between voltage and distance of each of the sub-areas is obtained according to the voltage information of the second point relative to the reference position under different excitation states and the distance information between the second point and the electrode patch; and

[0041] During the positioning stage, the voltage information of the third site on the application device relative to the reference site, the sub-region information where the application device is located, and the spatial position information of the electrode patch, which are synchronously collected under different excitation states, are obtained, and the spatial position information of the third site is calculated using the fitting model of the corresponding sub-region and the spatial position information of the electrode patch, wherein the spatial position information of the electrode patch is calculated based on the magnetic field strength information at the electrode patch.

[0042] Optionally, obtaining a fitting model for describing a voltage-distance mapping relationship for each of the sub-regions according to voltage information of the second site relative to the reference site under different excitation states and distance information between the second site and the electrode patch includes:

[0043] The voltage information of the second site relative to the reference position under different excitation states and the distance information between the second site and the electrode patch are combined into a first type of voltage-distance data pair, and fitting is performed to obtain a fitting model for describing the mapping relationship between voltage and distance under different excitation states in each sub-area.

[0044] Optionally, obtaining a fitting model for describing a voltage-distance mapping relationship for each of the sub-regions according to voltage information of the second site relative to the reference site under different excitation states and distance information between the second site and the electrode patch includes:

[0045] For each of the electrode patches, the voltage information of the second site relative to the reference position under different excitation states associated with the electrode patch and the distance information between the second site and the electrode patch are combined into a first type of voltage-distance data pair, and fitting is performed to obtain a fitting model for each of the electrode patches under different excitation states associated with it in each of the sub-areas.

[0046] Optionally, calculating the spatial position information of the third site by using the fitting model of the corresponding sub-region and the spatial position information of the electrode patch includes:

[0047] The distance information between the third site and the electrode patch is calculated using the fitting model corresponding to the electrode patch of the corresponding sub-region;

[0048] The spatial position information of the third site is calculated according to the distance information between the third site and the electrode patch and the spatial position information of the electrode patch.

[0049] Optionally, the calculating the distance information between the third site and the electrode patch by using the fitting model corresponding to the electrode patch of the corresponding sub-region includes:

[0050] From all fitting models of the electrode patch in different excitation states related to the electrode patch in the corresponding sub-region, selecting a fitting model that meets a first preset condition as a target fitting model;

[0051] According to the target fitting model, the distance information between the third site and the electrode patch is calculated.

[0052] Optionally, calculating the spatial position information of the third site by using the fitting model of the corresponding sub-region and the spatial position information of the electrode patch includes:

[0053] Selecting at least three electrode patches that meet a second preset condition from all the electrode patches as target electrode patches;

[0054] The fitting model of the corresponding sub-region is used to calculate the distance information between the third site and each of the target electrode patches, and the spatial position information of the third site is calculated according to the spatial position information of each of the target electrode patches.

[0055] Optionally, the application device further includes a fourth site, and the positioning method further includes:

[0056] During the positioning stage, the magnetic field strength information of the fourth site is obtained, the spatial position and direction information of the fourth site is calculated based on the magnetic field strength information of the fourth site, and the sub-area information where the application device is located is obtained based on the spatial position and direction information of the fourth site.

[0057] Optionally, the application device further includes a fifth site, and the positioning method further includes:

[0058] In the positioning stage, the voltage information of the fifth site relative to the reference site synchronously collected under all excitation states is obtained, the spatial position information of the fifth site is calculated according to the spatial position and direction information of the fourth site and the spatial distance information between the fourth site and the fifth site, and the distance information between the fifth site and the electrode patch is calculated according to the spatial position information of the fifth site and the spatial position information of the electrode patch, and the voltage information of the fifth site relative to the reference site under different excitation states and the distance information between the fifth site and the electrode patch are combined into a second type of voltage-distance data pair, and the second type of voltage-distance data pair is used to update the fitting model of the corresponding sub-area.

[0059] Optionally, the positioning method further includes:

[0060] The voltage information of the third site relative to the reference position under different excitation states and the distance information between the third site and the electrode patch are combined into a third type of voltage-distance data pair, and valid data pairs are screened out from the third type of voltage-distance data pairs, and the valid data pairs are used to update the fitting model of the corresponding sub-area.

[0061] To achieve the above-mentioned object, the present invention further provides an electronic device, including a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the positioning method of the interventional device described above is implemented.

[0062] In order to achieve the above-mentioned object, the present invention further provides a readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the positioning method of the interventional device described above is implemented.

[0063] Compared with the prior art, the positioning system, method, interventional surgery system, electronic device and storage medium of the interventional device provided by the present invention have the following advantages: the present invention divides the target area into multiple sub-areas, and uses a learning device in the fitting stage to obtain a fitting model for each sub-area for describing the mapping relationship between voltage and distance. Then, in the positioning stage, the distance between the third site and the electrode patch on the application device is obtained based on the fitting model of the sub-area where the application device is located. According to the distance between the third site and the electrode patch and the spatial position information of the electrode patch, the position of the third site can be obtained, thereby realizing the positioning of the application device, and further determining the position, direction and shape information of the application device in the target area of ​​the target object. Therefore, the present invention divides the target area into multiple sub-areas, and establishes a fitting model for each sub-area respectively. Since the electric field is linear in a small local range, through these fitting models, the distance between the third site and the electrode patch can be obtained more accurately, thereby realizing the positioning calculation. In addition, since the present invention establishes a fitting model for each sub-area respectively, the calculation amount of fitting is small, which can effectively reduce the calculation amount and save time cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 It is a schematic diagram of working modules of a positioning system for an interventional device in one embodiment of the present invention;

[0065] Figure 2 for Figure 1 The schematic diagram of the use process of the positioning device shown;

[0066] Figure 3 A schematic diagram of a flow chart of a positioning algorithm implementation in one embodiment of the present invention;

[0067] Figure 4a is a schematic structural diagram of a ring-shaped catheter in one embodiment of the present invention;

[0068] Figure 4b for Figure 4a A schematic diagram of the arrangement of various sensors (sites) in the annular catheter shown;

[0069] Figure 4c for a certain moment Figure 4a The schematic diagram of the positioning result of the annular catheter is shown;

[0070] Figure 5 A schematic diagram of the division of the target area in one embodiment of the present invention;

[0071] Figures 6a to 6e It is a scatter diagram of voltage-distance data pairs accumulated in a sub-region under different excitation states in a certain fitting stage;

[0072] Figure 7 A schematic diagram of the distance between the second site and each electrode patch in one embodiment of the present invention;

[0073] Figure 8 It is a schematic diagram of the block structure of an electronic device in one embodiment of the present invention.

[0074] The reference numerals are as follows:

[0075] Target object-100; target area-101; sub-area-1011; electrode patches-102, 102H, 102F, 102C, 102B, 102R, 102L; first magnetic field sensor-103P; second magnetic field sensor-103Q; electrode-104; first electrode-104S, 104S1, 104S2; second electrode-104T, 104T1, 104T2; intervention device-105; operating handle-106; magnetic field-107; display unit-108; three-dimensional body cavity model-109; terminal model-110; movement trajectory-111;

[0076] Magnetic field generating unit-10; excitation control unit-20; data acquisition unit-30; controller-40; communication control unit-50;

[0077] Processor 301; communication interface 302; memory 303; communication bus 304. DETAILED DESCRIPTION

[0078] The following is combined with Figures 1 to 8 The positioning system, method, interventional surgical system, electronic device and storage medium of the interventional device proposed in the present invention are further described in detail with specific implementation methods. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the implementation methods of the present invention. In order to make the purposes, features and advantages of the present invention more obvious and easy to understand, please refer to the drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Any modification of the structure, change in the proportional relationship or adjustment of the size, under the condition that the effects and purposes that can be achieved by the present invention are the same or similar, should still fall within the scope of the technical content disclosed by the present invention.

[0079] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0080] The core idea of ​​the present invention is to provide an interventional device positioning system, method, interventional surgery system, electronic device and storage medium, which can locate and track the interventional device in the target object, reduce the calculation amount of positioning, and save time cost.

[0081] It should be noted that the electronic device according to the embodiment of the present invention may be a personal computer, a mobile terminal, etc. The mobile terminal may be a mobile phone, a tablet computer, or other hardware device with various operating systems.

[0082] To realize the above idea, the present invention provides a positioning system for an interventional device, wherein the interventional device includes a learning tool and an application tool, wherein the learning tool and the application tool are used to be placed in a target area of ​​a target object. The positioning system includes a magnetic field generating unit, an excitation control unit, a data acquisition unit and a controller.

[0083] Wherein, the magnetic field generating unit is used to generate a magnetic field passing through the target object.

[0084] The excitation control unit is used to generate an N-axis electric field in the target object by applying excitation between at least three electrode patches arranged on the surface of the target object, where N≥3.

[0085] The controller is used to divide the target area into a plurality of sub-areas.

[0086] The data acquisition unit is used to synchronously collect the magnetic field strength information of the first point on the learning device, the magnetic field strength information at the electrode patch, and the voltage information of the second point on the learning device relative to a reference position under all excitation states in each of the sub-areas during the fitting stage; and synchronously collect the magnetic field strength information at the electrode patch and the voltage information of the third point on the application device relative to the reference position under all excitation states during the positioning stage.

[0087] The controller is also used to calculate the spatial position information of the second site in each of the sub-regions in a fitting stage based on the magnetic field strength information of the first site and the spatial distance information between the first site and the second site, and obtain a fitting model for each of the sub-regions for describing the mapping relationship between voltage and distance based on the voltage information of the second site relative to the reference site under different excitation states and the distance information between the second site and the electrode patch; and, in a positioning stage, calculate the spatial position information of the third site based on the voltage information of the third site relative to the reference site under different excitation states and the sub-region information where the application device is located, using the fitting model of the corresponding sub-region and the spatial position information of the electrode patch, wherein the spatial position information of the electrode patch is calculated based on the magnetic field strength information at the electrode patch.

[0088] Thus, the positioning system of the present invention is divided into a fitting stage and a positioning stage when in use, and the target area is divided into a plurality of sub-areas, wherein a learning device is used in the fitting stage to obtain a fitting model for describing the mapping relationship between voltage and distance in each sub-area. Then, in the positioning stage, the distance between the third site and the electrode patch on the application device is obtained based on the fitting model of the sub-area where the application device is located. According to the distance between the third site and the electrode patch and the spatial position information of the electrode patch, the position of the third site can be obtained, thereby realizing the positioning of the application device, and further determining the position, direction and shape information of the application device in the target area of ​​the target object. Thus, the present invention divides the target area into a plurality of sub-areas, and establishes a fitting model for each sub-area respectively. Since the electric field is linear in a small local range, through these fitting models, the distance between the third site and the electrode patch can be obtained more accurately, thereby realizing the positioning calculation. In addition, since the present invention establishes a fitting model for each sub-area respectively, the calculation amount of fitting is small, which can effectively reduce the calculation amount and save time cost. It should be noted that, as can be understood by those skilled in the art, specifically, the spatial position information of the second site is first calculated through the magnetic field strength information of the first site to obtain the spatial position and direction information of the first site, and then calculated based on the spatial position and direction information of the first site and the spatial distance information between the first site and the second site. The distance information between the second site and the electrode patch is calculated based on the spatial position information of the second site and the spatial position information of the electrode patch.

[0089] Further, the controller is used to form a first type of voltage-distance data pair with the voltage information of the second site relative to the reference site under different excitation states and the distance information between the second site and the electrode patch, and perform fitting to obtain a fitting model for describing the mapping relationship between voltage and distance under different excitation states in each sub-region. Thus, by fitting the voltage information of the second site relative to the reference site under different excitation states and the distance information between the second site and the electrode patch to form a first type of voltage-distance data pair, the fitting model under different excitation states in each sub-region can be quickly and accurately obtained.

[0090] Furthermore, the controller is used to calculate the distance information between the third site and the at least three electrode patches using the fitting model under different excitation states in the corresponding sub-region, and calculate the spatial position information of the third site based on the distance information between the third site and the at least three electrode patches and the spatial position information of the at least three electrode patches. Therefore, the present invention can further improve the calculation accuracy of the spatial position information of the third site by calculating the spatial position information of the third site based on the distance information between the third site and the at least three electrode patches and the spatial position information of the at least three electrode patches.

[0091] The following combination Figure 1-5 The positioning system of the interventional device provided by the present invention is introduced in detail.

[0092] Please refer to Figure 1 , which schematically shows a schematic diagram of a working module of a positioning system for an interventional device provided by an embodiment of the present invention. Figure 1 As shown, the target object 100 is the application object of the positioning system in the present invention, which may be a person, an animal or other suitable conductor object. The target area 101 represents the area inside the target object 100 where the end of the intervention device 105 is located, such as a heart cavity.

[0093] The interventional device 105 may be any medical catheter, such as an electrophysiological catheter, a multi-limb catheter or a ring catheter for ablation or mapping, or other implantable devices. When the interventional device 105 is an electrophysiological catheter, it is generally used for diagnosis or treatment, such as electrocardiographic mapping or delivery of ablation energy. Figure 1 The interventional device 105 shown is an electrophysiological catheter, which generally reaches the target area 101, such as the heart cavity, through a vascular passage. The end of the interventional device 105 can be fixed or adjustable; the part of the interventional device 105 remaining outside the body generally has an operating handle 106, and the doctor can control the shape or orientation of the end of the interventional device 105 by operating the handle 106.

[0094] The intervention device 105 is equipped with two types of sensors, including a magnetic field sensor (hereinafter, for the sake of distinction, the magnetic field sensor installed on the intervention device is referred to as the first magnetic field sensor 103P) and a voltage sensor (i.e., a common electrode, hereinafter referred to as electrode 104). Specifically, the first magnetic field sensor 103P is installed at the first point on the intervention device, the first voltage sensor (hereinafter referred to as the first electrode 104S) is installed at the second point, and the second voltage sensor (hereinafter referred to as the second electrode 104T) is installed at the third point. The signals sensed by the first magnetic field sensor 103P and the electrode 104 are transmitted to the data acquisition unit 30 through the wires inside the intervention device 105. There can be one or more first magnetic field sensors 103P, first voltage sensors, and second voltage sensors.

[0095] According to the function of the intervention device 105 in the positioning process, the intervention device 105 may include a learning device and an application device. Both the learning device and the application device are required to be equipped with at least one first magnetic field sensor 103P (the sub-region information of the application device in the positioning stage is determined by the first magnetic field sensor 103P installed thereon). In addition, the learning device is also equipped with at least one first electrode 104S with a fixed and known spacing value from its first magnetic field sensor 103P, and the application device is also equipped with several second electrodes 104T to be positioned. Of course, this is only a functional distinction. In actual applications, the application device and the learning device can be the same device. Taking the intervention device 105 as a medical catheter as an example, the intervention device can include two catheters, namely a learning catheter (i.e., a learning device) and an application catheter (i.e., an application device). The intervention device can also include only one catheter, which can be used as both a learning catheter and an application catheter. Of course, in other embodiments, the intervention device can also include at least three catheters, one or more of which are used as learning catheters, and the rest are application catheters. This is reasonable and the present invention does not limit this.

[0096] The following is an introduction using the intervention device 105 as a medical catheter as an example. In the following description, for simplicity, it is assumed that the medical catheter has a first magnetic field sensor 103P, a first electrode 104S with a fixed and known distance from the first magnetic field sensor 103P, and several other second electrodes 104T to be located. At this time, the medical catheter is used as both a learning catheter and an application catheter. The distance is the Euclidean distance in three-dimensional space. In this way, the position information of the first electrode 104S can be calculated based on the spatial position and direction information of the first magnetic field sensor 103P, and the position information of the second electrode 104T needs to be obtained by the positioning method described in the present invention. It should be noted that the first point on the medical catheter described in the present invention is the position of the first magnetic field sensor 103P, the second point is the position of the first electrode 104S, and the third point is the position of the second electrode 104T. Therefore, calculating the spatial position of the second point and the third point is calculating the spatial position of the first electrode 104S and the second electrode 104T.

[0097] The magnetic field sensor generally includes several coils, which can be used to sense the magnetic field strength at its location, and the magnetic field is excited by the magnetic field generating unit 10. The controller 40 can calculate the spatial position information and direction information of the magnetic field sensor based on the magnetic field strength information sensed by the magnetic field sensor. The specific calculation method belongs to the category of magnetic positioning technology, and can refer to the prior art, which will not be described here. The spatial position information generally refers to the three coordinate values ​​of x, y and z in the three-dimensional Cartesian coordinate system. The direction information refers to the direction vector of the magnetic field sensor, more generally, its unit direction vector.

[0098] Electrode 104 (i.e., voltage sensor) is a metal with good biocompatibility, such as platinum-iridium alloy and gold. Electrode 104 is used to measure the voltage at its position relative to a reference position. The reference position ( Figure 1 The reference electrode 104 is generally a relatively stable position, which may be a position on the body surface or a position in the body (such as the coronary sinus). Preferably, a reference electrode is placed at the reference position (such as the coronary sinus). In addition, in addition to measuring voltage, the electrode 104 may also be used to measure electrophysiological signals or release ablation energy.

[0099] The magnetic field generating unit 10 is used to generate a magnetic field 107, and is generally fixed near the target object 100. In this way, the magnetic field 107 generated by it can pass through the target object 100. The magnetic field 107 can be sensed by the magnetic field sensor to locate the spatial position and direction of the magnetic field sensor.

[0100] The electrodes attached to the surface of the target object 100 are generally sheet-shaped (in order to distinguish them from the electrodes 104 on the medical catheter mentioned above, hereinafter referred to as "electrode patches 102"), and the number is generally not less than 3. The excitation control unit 20 can apply a specific electric field to the human body through any two electrode patches 102, that is, apply excitation, preferably applying a constant current or constant voltage signal; preferably, the applied current flows through the target area 101. The excitation control unit 20 will select multiple pairs of electrode patches 102 in the electrode patches 102 to apply excitation, and the data acquisition unit 30 will collect the voltage value of each electrode 104 (including 104S and 104T) on the medical catheter relative to the reference position under all excitation states at the same sampling time for subsequent positioning calculations. In addition, each of the electrode patches 102 is equipped with a magnetic field sensor (for the sake of distinction, the magnetic field sensor on the electrode patch 102 is referred to as the second magnetic field sensor 103Q), which is used to provide spatial position information, that is, the controller can calculate the spatial position information of the second magnetic field sensor 103Q based on the magnetic field strength information sensed by the second magnetic field sensor 103Q on each electrode patch 102, and use the spatial position information of the second magnetic field sensor 103Q as the spatial position information of the electrode patch 102. The same sampling moment refers to the moment of collecting the magnetic field strength data of the magnetic field sensor (including the first magnetic field sensor 103P and the second magnetic field sensor 103Q) and the voltage information of each electrode 104 relative to the reference position, that is, the data acquisition unit 30 needs to collect the magnetic field strength data and voltage information at the same sampling moment. The excitation state refers to the state in which the excitation control unit 20 applies current to the human body through two of the electrode patches 102 (a pair of electrode patches), which can also be called an excitation axis. When the number of excitation axes is N, it can be considered that the excitation control unit 20 applies excitation to N pairs of electrode patches 102, thereby generating an N-axis electric field in the target object 100. The position of the electrode patch 102 on the body surface is generally fixed during the entire operation.

[0101] In order to obtain the voltage information of the second site and the third site (i.e., each electrode 104) relative to the reference site under all excitation states at the same sampling time, the following method can be used: the excitation control unit 20 applies excitation between the at least three electrode patches 102 and performs high-speed switching between all excitation states in a continuous cycle, and the data acquisition unit 30 acquires the voltage information of the second site and the third site (i.e., each electrode 104) relative to the reference site under all excitation states; or,

[0102] The excitation control unit 20 applies excitation to the at least three electrode patches 102 simultaneously, but the frequencies of the applied excitations are different from each other, and the data acquisition unit 30 collects voltage information of the second site and the third site (i.e., each electrode 104) relative to the reference site and performs filtering processing to obtain voltage information of the second site and the third site (i.e., each electrode 104) relative to the reference site under all excitation states; or,

[0103] The excitation control unit 20 applies excitation between the at least three electrode patches 102 at the same time, but the frequencies of the applied excitation are different. The data acquisition unit 30 collects voltage information of the second site and the third site (i.e., each electrode 104) relative to a reference position. The controller 40 filters the voltage information of the second site and the third site (i.e., each electrode 104) relative to the reference position collected by the data acquisition unit 30 to obtain the voltage information of the second site and the third site (i.e., each electrode 104) relative to the reference position under all excitation states.

[0104] exist Figure 1 In the embodiment shown, there are 6 electrode patches 102, which are respectively located at the back of the neck (H), groin (F), chest (C), back (B), left armpit (L) and right armpit (R). The excitation control unit 20 can select every two electrode patches 102 to apply excitation respectively, so there are 15 excitation states, which can also be called 15 excitation axes: RL, HF, CB, CR, CL, CH, CF, RB, LB, HB, FB, RF, LF, HR and HL. It should be noted that the present invention does not limit the excitation control unit 20 to apply excitation between every two electrode patches 102. As long as excitation is applied between N pairs of electrode patches 102, N (N≥3) axis electric fields can be generated in the target area 101 of the target object 100. In actual application, there may be a situation where the current flowing through the target area 101 due to the excitation applied by one or more excitation axes is small, resulting in the electrode 104 in the target area 101 not being able to measure the voltage value under the one or more excitation states or the measured voltage value under the one or more excitation states being significantly low. In this case, the excitation control unit 20 may abandon the one or more excitation states (invalid excitation states) and no longer use them in subsequent calculations. The protection scope of the present invention should cover this situation. When one or more excitation states are abandoned, the different excitation states involved in the calculation include n valid excitation states selected from all the excitation states, n≥3, N and n are both natural numbers, and when all the excitation states are valid after screening, N may also be equal to n. Of course, if the excitation states are not screened, the different excitation states involved in the calculation may also include all the excitation states.

[0105] In order to obtain the voltage information of each electrode 104 relative to the reference position under all excitation states at the same sampling moment, two implementation methods, time division or frequency division, can be used. Among them, the time division method is: that is, high-speed switching is performed continuously and cyclically between 15 types of excitations, and the voltage value of each electrode 104 relative to the reference position under all excitation states is collected. When the switching frequency is high enough, it can be considered that the voltage value of each electrode 104 relative to the reference position under all excitation states is collected at the same time. The switching frequency can be 200kHz or 300kHz. The frequency division method is: that is, signals of different frequencies are applied to the 15 excitation axes respectively, and then the data acquisition unit 30 or the controller 40 filters the signals collected at the electrode 104 to obtain the voltage values ​​under all excitation states. For example, constant current / constant voltage signals of 10kHz, 10.5kHz, 11kHz, 11.5kHz... etc. can be applied respectively. It is preferred to use the frequency division method.

[0106] The data acquisition unit 30 is used to process the data transmitted by all sensors in the positioning system, including the magnetic field sensor and the voltage sensor (i.e., the electrode 104). Generally, amplification, filtering, and analog-to-digital conversion are performed. As far as the positioning function to be implemented in the present invention is concerned, the data that the data acquisition unit 30 needs to collect at each sampling time are:

[0107] 1. Magnetic field intensity data at each magnetic field sensor (including the first magnetic field sensor 103P and the second magnetic field sensor 103Q);

[0108] 2. Voltage data of each electrode 104 (including the first electrode 104S and the second electrode 104T) relative to a reference position in all excitation states.

[0109] like Figure 1 As shown, the positioning system further includes a communication control unit 50, which is used to connect the controller 40 and the excitation control unit 20, the data acquisition unit 30, and the magnetic field generating unit 10 to control the communication and data transmission between the controller 40 and the magnetic field generating unit 10, the excitation control unit 20, and the data acquisition unit 30. The communication control unit 50 is a "transfer station" for signal and data transmission, and the transmission mode can be selected from serial port, serial peripheral interface (Serial Peripheral Interface, SPI), I 2 C, wired methods such as network port and USB, wireless methods such as wifi and Bluetooth can also be selected. In addition, in addition to being used to connect the various unit modules in the positioning system, the communication control unit 50 may also be used to connect other equipment, such as radiofrequency ablation equipment, CT equipment, MRI equipment, electrocardiographs and other commonly used equipment in surgery.

[0110] The controller 40 is generally a general-purpose computer and is the core of system control and data processing. It can control the operation of the system through the communication control unit 50. The controller 40 is specifically used to divide the target area into multiple sub-areas. The controller 40 also has the following functions:

[0111] 1. Control the start and stop of the magnetic field generating unit 10 and the working mode of the excitation control unit 20;

[0112] 2. Control the data acquisition unit 30 to synchronously collect the magnetic field strength of each magnetic field sensor (including the first magnetic field sensor 103P and the second magnetic field sensor 103Q) and the voltage value of each electrode 104 (including the first electrode 104S and the second electrode 104T) relative to the reference position;

[0113] 3. Based on the voltage value at the first electrode 104S and the distance between the first electrode 104S and the electrode patch 102, a fitting model for describing the mapping relationship between voltage and distance is established for each sub-region;

[0114] 4. Based on the fitting model of the corresponding sub-region and the voltage value at the second electrode 104T, the distance between the second electrode 104T and each electrode patch 102 is calculated, and then the spatial position of the second electrode 104T is calculated.

[0115] The controller 40 generally uses software programming to perform the above functions. The software can be downloaded to a computer or used through a network. In addition, a memory can also be set in the controller 40 to store the data of each sensor and the relevant data in the positioning process.

[0116] In addition, preferably, Figure 1 As shown, the positioning system further includes a display unit 108, which is generally a display, which may be a CRT or LCD, etc. The display unit 108 is connected to the controller 40 for communication, and is used to display the position, direction, shape and / or motion trajectory of the application device of the intervention device 105 in the target object 100, wherein the position, direction, shape and / or motion trajectory of the application device of the intervention device 105 in the target object 100 is determined by the controller 40 according to the positioning result of the third site. It can be understood that a three-dimensional spatial model of the target object 100 can be pre-constructed during surgery, so that after the spatial position of the third site is located, the application catheter can be simulated according to the spatial position of the third site, and then the position, direction and shape of the application catheter in the target object 100 are determined. Furthermore, since the position, direction and shape of the application catheter in the target object 100 are determined at each sampling time, the motion trajectory of the application catheter in the target object 100 can be further determined. Figure 1The display unit 108 displays a three-dimensional body cavity model 109 and a terminal model 110 of the application catheter in the body cavity drawn based on the positioning result of the controller 40. Of course, in other embodiments, the display unit 108 can also be used to display the position, direction, shape and / or the motion trajectory of the learning tool in the target object 100, and the position, direction, shape and / or the motion trajectory of the learning tool in the target object 100 is determined by the controller 40 based on the positioning results of the first site and the second site.

[0117] Please continue to refer to Figure 2 , which schematically shows a schematic diagram of the use process of the positioning system provided by the present invention, such as Figure 2 As shown, the use process of the positioning system specifically includes the following steps:

[0118] Step S110: At the beginning of the operation, a magnetic field and a multi-axis electric field are applied to the human body, and the target area 101 is divided into a plurality of sub-areas 1011 (see Figure 5 ). Generally, a magnetic field is applied by a magnetic field generating unit 10, and a multi-axis electric field is generated by attaching a plurality of electrode patches 102 to the surface of the target object 100 and applying different current excitations between the electrode patches 102. Constant current excitation or constant voltage excitation can be selected. The reason for dividing the target area 101 into a plurality of sub-areas 1011 is that the electric field is distributed nonlinearly as a whole in the body, but the electric field in a small local area can be approximately considered to be linear. In each of the divided small sub-areas, when the electric field is linear, the relationship between voltage and distance is linear, and the linear fitting calculation performed at this time is meaningful.

[0119] The following process involves two stages, a fitting stage and a positioning stage. The learning catheter is operated in the fitting stage, and the application catheter is operated in the positioning stage. The learning catheter and the application catheter are only functional distinctions of the catheter. In fact, the same catheter may be used for both the fitting stage and the positioning stage. The fitting stage is started earlier than the positioning stage, but the two stages are allowed to operate simultaneously for some time periods. The fitting stage can start after the learning catheter is delivered into the target area 101 (e.g., the heart cavity) through the vascular access. The learning catheter is integrated with at least one first magnetic field sensor 103P and at least one first electrode 104S, and the distance between the two is fixed, and the distance information is known, so that the position information of the first electrode 104S can be calculated by the position and direction information of the first magnetic field sensor 103P and the distance information between the two.

[0120] The specific steps include:

[0121] Step S120 : placing the learning catheter into the target region 101 (eg, a cardiac cavity) and roaming through each sub-region 1011 .

[0122] Step S130: During this period, the following data are measured continuously and synchronously:

[0123] 1. Learn the magnetic field strength information at the first magnetic field sensor 103P on the catheter. After being sent to the controller 40, the magnetic field strength information will be used to calculate the spatial position and direction information of the first magnetic field sensor 103P at each moment;

[0124] 2. Learn the voltage information of the first electrode 104S on the catheter relative to a reference position. The reference position is generally a relatively fixed position, which can be on the body surface or at a certain position in the heart cavity (generally selected in the coronary sinus). The voltage is the voltage in response to the various excitation states mentioned above;

[0125] 3. Magnetic field strength information at the second magnetic field sensor 103Q on each electrode patch 102. After being sent to the controller 40, the magnetic field strength information is used to calculate the spatial position information of the second magnetic field sensor 103Q at each moment (ie, the spatial position information of the corresponding electrode patch 102).

[0126] Step S140: While collecting data, the controller 40 will continuously determine whether sufficient data has been accumulated based on subsequent calculation requirements. If the amount of data is insufficient, the learning catheter needs to continue to be in a roaming state until the amount of data is sufficient, and then the display unit 108 will prompt the operator to stop the fitting stage. The judgment method can choose to set a fixed operation time, or it can be prompted to stop after the fitting error is reduced to a certain level through continuous fitting attempts.

[0127] Step S150: After sufficient data is accumulated, the positioning phase begins. The application catheter is placed into the target area 101 (eg, a cardiac cavity), and the voltage information of each second electrode 104T on the application catheter relative to the reference position is measured.

[0128] Step S160 : the controller 40 calculates the spatial position of each second electrode 104T at each moment according to the voltage value at each second electrode 104T at each moment. The specific calculation method will be described later.

[0129] It should be noted that during the entire application process, including the fitting phase and the positioning phase, the reference position and the positions of the electrode patches 102 used to apply stimulation must remain relatively stable. If some operations (such as the patient turning over) cause the displacement of the electrode patches 102 to exceed a certain threshold, the fitting phase must be restarted.

[0130] From the above description, it can be seen that the basic idea of ​​the positioning algorithm of the present invention is as follows:

[0131] 1. Applying a magnetic field and a multi-axis electric field to the body, wherein the magnetic field is generated by a magnetic field generating unit 10, and the electric field is generated by applying a constant current excitation / constant voltage excitation to an electrode patch 102 on the body surface;

[0132] 2. Divide the target area 101 into small sub-areas 1011. In each sub-area 1011, fit the voltage data measured at the first electrode 104S (the electrode with a known position) and the distance relationship between the first electrode 104S and the electrode patch 102 to obtain a fitting model for describing the mapping relationship between voltage and distance in each sub-area 1011.

[0133] 3. Measure the voltage data at the second electrode 104T to be located, and use the fitting model of the corresponding sub-region to calculate the distance between the second electrode 104T and the plurality of electrode patches 102 to calculate the spatial position of the second electrode 104T.

[0134] Please continue to refer to Figure 3 , which schematically gives a specific example of the above positioning algorithm:

[0135] Step S210 : Divide the target region 101 (eg, cardiac cavity) into a plurality of sub-regions 1011 .

[0136] Step S220: Place the learning catheter equipped with the first magnetic field sensor 103P and the first electrode 104S into the target area 101 (e.g., the heart cavity) and then roam through each sub-area 1011, and collect the magnetic field strength data at the first magnetic field sensor 103P and the second magnetic field sensor 103Q and the voltage data at the first electrode 104S at each moment; calculate the position and direction of the first magnetic field sensor 103P according to the magnetic field strength data at the first magnetic field sensor 103P, and calculate the position of the second magnetic field sensor 103Q according to the magnetic field strength data at the second magnetic field sensor 103Q; calculate the position of the first electrode 104S according to the position and direction of the first magnetic field sensor 103P and the distance between the first magnetic field sensor 103P and the first electrode 104S, and then calculate the distance from the first electrode 104S to each second magnetic field sensor 103Q (i.e., calculate the distance from the first electrode 104S to each electrode patch 102) according to the position of the first electrode 104S and the position of each second magnetic field sensor 103Q (i.e., calculate the distance from the first electrode 104S to each electrode patch 102).

[0137] Step S230: In each sub-region 1011, for each electrode patch 102, the voltage data collected at the first electrode 104S in all relevant excitation states and the distance relationship between the first electrode 104S and the electrode patch 102 are fitted to obtain several fitting models. The fitting model is used to describe the relationship between the voltage data of each position where the electrode 104 roams in a sub-region 1011 relative to the reference position in each excitation state and the distance between the electrode 104 and each electrode patch 102 on the body surface. Assuming that there are M electrode patches 102 on the body surface of the target object, any two of the M electrode patches 102 are used to apply excitation, then for a certain electrode patch 102, there are M-1 excitation states related to the electrode patch 102. For these M-1 excitation states, at each sampling moment, there will be M-1 voltage values ​​at the first electrode 104S, so there will be M-1 voltage-distance data pairs, and M-1 fitting models for describing the mapping relationship between voltage and distance can be generated. Then in each sub-area 1011, for M electrode patches, there are a total of M*(M-1) fitting models. The fitting method preferably uses a linear fitting method, and more preferably uses a least squares linear fitting method. It should be noted that, as can be understood by those skilled in the art, in some other embodiments, other fitting methods besides the linear fitting method may also be selected, and the present invention is not limited to this.

[0138] Step S240: For a second electrode 104T to be positioned on the application catheter, for a certain electrode patch 102, the distance from the second electrode 104T to the electrode patch 102 is calculated based on several fitting models corresponding to the electrode patch 102 in the sub-area 1011 where the application catheter is located and the voltage value at the second electrode 104T.

[0139] For a certain electrode patch 102, there are M-1 fitting models. Preferably, a fitting model that satisfies the first preset condition can be selected as a target fitting model, and the distance between the second electrode 104T and the electrode patch 102 can be calculated according to the target fitting model. For example, a model with the smallest fitting error can be selected from the M-1 fitting models to participate in the calculation. Of course, in some other embodiments, multiple fitting models can also be used simultaneously for weighted calculation.

[0140] Step S250: Calculate the position of the second electrode 104T based on the distance between the second electrode 104T to be located and each electrode patch 102. In the specific calculation, the position of the second electrode 104T can be calculated based on the distance between the second electrode 104T and each of the electrode patches 102, that is, all electrode patches 102 can be selected to participate in the calculation. It is also possible to select at least three electrode patches 102 that meet the second preset condition from all the electrode patches 102 as target electrode patches, and calculate the position of the second electrode 104T based on the distance between the second electrode 104T and each of the target electrode patches. For example, at least three electrode patches 102 with high data stability or good abutment can be selected from all the electrode patches 102 to participate in the calculation.

[0141] A learning catheter equipped with a first magnetic field sensor 103P and a first electrode 104S is placed into the heart cavity and then roamed for a period of time; the magnetic field intensity data at the first magnetic field sensor 103P and the voltage data at the first electrode 104S are synchronously collected at each sampling time; the position and direction of the first magnetic field sensor 103P are calculated according to the magnetic field intensity data at the first magnetic field sensor 103P; the position of the first electrode 104S is calculated according to the position and direction of the first magnetic field sensor 103P and the distance between the first magnetic field sensor 103P and the first electrode 104S. Specifically, the spatial position of the first electrode 104S (i.e., the second site) can be calculated according to the formula P2=P1+D1·d', where P2 represents the spatial position of the first electrode 104S (i.e., the second site), P1 and D1 represent the spatial position and direction of the first magnetic field sensor 103P (i.e., the first site) respectively (the direction is from the first magnetic field sensor 103P to the first electrode 104S), and d' represents the spatial distance between the first magnetic field sensor 103P and the first electrode 104S.

[0142] In an exemplary embodiment, the application catheter may include a fourth site and a fifth site, so that in the positioning stage, the data acquisition unit 30 can also synchronously collect the magnetic field strength information of the fourth site and the voltage information of the fifth site relative to the reference site under all excitation states at each sampling moment. Accordingly, the controller 40 calculates the spatial position information of the fifth site according to the spatial position and direction information of the fourth site and the spatial distance between the fourth site and the fifth site, and calculates the distance information between the fifth site and the electrode patch according to the spatial position information of the fifth site and the spatial position information of the electrode patch, and forms the voltage information of the fifth site relative to the reference site under different excitation states and the distance information between the fifth site and the electrode patch into a second type of voltage-distance data pair, and uses the second type of voltage-distance data pair to update the fitting model of the corresponding sub-region. It should be noted that, as can be understood by those skilled in the art, in the positioning stage, at each sampling moment, the controller can obtain the sub-region information where the application device is located according to the spatial position and direction information of the fourth site.

[0143] For example, the learning catheter and the application catheter are the same catheter, that is, the fourth site and the first site are actually the same site, and the fifth site and the second site are actually the same site, then the controller 40 will continuously obtain new voltage-distance data pairs (i.e., the second type of voltage-distance data pairs) during the positioning stage, and can also participate in the fitting calculation. Alternatively, the application catheter and the learning catheter are not the same catheter, but the first magnetic field sensor 103P is set at the fourth site on the application catheter, and the first electrode 104S is set at the fifth site, so that the controller 40 will also continuously obtain new voltage-distance data pairs (i.e., the second type of voltage-distance data pairs) during the positioning stage.

[0144] For the continuously acquired second type of voltage-distance data pairs, there are three processing methods, and the third method is preferably used:

[0145] a. Maintaining the fitting model calculated in the previous fitting stage unchanged, that is, not using the second type of voltage-distance data pair to perform new fitting calculations, so as to reduce calculation overhead;

[0146] b. Update the fitting model calculated by the first type of voltage-distance data pairs of the corresponding sub-area 1011 according to the second type of voltage-distance data pairs to obtain a new fitting model, that is, the first type of voltage-distance data pairs of the sub-area 1011 accumulated in the previous fitting phase and the second type of voltage-distance data pairs of the sub-area 1011 continuously increased in the positioning phase are used together for fitting calculation. In this way, the data pairs involved in the fitting are constantly accumulated, and the fitting model is also constantly updated, so that the latest fitting model can be used for positioning calculation;

[0147] c. For each sub-area 1011, only the first type of voltage-distance data pairs and / or the second type of voltage-distance data pairs accumulated in a period of time before the current moment are used for fitting, that is, the data used for fitting is similar to a first-in-first-out data queue. This is because the data acquisition environment will inevitably change slowly over time, and only using the data in a period of time before the current moment for fitting can avoid the influence of premature data on the accuracy of the fitting model. In this way, the data pairs involved in the fitting are constantly updated, and the fitting model is also constantly updated, so that the latest fitting model can always be used for positioning calculation.

[0148] It can be understood that, for the voltage-distance data pairs involved in the calculation of the fitting model in the above-mentioned embodiment, the voltage data is directly measured by the first electrode 104S, and the distance data refers to the spatial distance information between the first electrode 104S and the electrode patch 102, wherein the position information of the first electrode 104S is calculated based on the position of the first magnetic field sensor 103P and the physical spacing information between the first magnetic field sensor 103P and the first electrode 104S. Therefore, it can be considered that the fitting model calculated based on these two types of data also describes the real correspondence between the two types of data. The reason for emphasizing this point is that in addition to the credible position data provided at the first electrode 104S with a known distance from the first magnetic field sensor 103P, after the positioning is completed at the other second electrode 104T to be positioned, a corresponding voltage-distance data pair will also be generated, but the position information of the second electrode 104T at this time is calculated by the positioning method described in the present invention, so there may be a certain error.

[0149] In another embodiment, the controller 40 may also form a third type of voltage-distance data pair with the voltage information of the third site relative to the reference site under different excitation states and the distance information between the third site and the electrode patch 102, and screen out valid data pairs from the third type of voltage-distance data pairs, and use the valid data pairs to update the corresponding fitting model of the sub-region 1011. For example, the positioning result based on the fitting model at the second electrode 104T can form a new voltage-distance data pair (i.e., the third type of voltage-distance data pair) again. After these data pairs are subjected to certain screening conditions (for example, the voltage-distance data pair at the second electrode 104T can also be added to the fitting calculation of the sub-region 1011 to which it belongs, if the fitting error of the sub-region 1011 can be reduced, it is a valid data pair, otherwise it is an invalid data pair), the valid data pair will also participate in the calculation update of the fitting model.

[0150] Therefore, through the positioning system provided by the present invention, the spatial coordinates of any position can be calculated based on the information of the limited positions (positions where the learning catheter has roamed) in the target area 101 to be positioned (for example, the heart cavity) (only by measuring the voltage data at the arbitrary position), so that the positioning and tracking of the device to be positioned (catheter) in the target area 1011 (for example, the heart cavity) can be completed.

[0151] The above positioning system is further explained below by taking a ring-shaped catheter as an example. The ring-shaped catheter is used as a learning catheter and an application catheter at the same time.

[0152] Please refer to Figures 4a to 4c ,in, Figure 4a A schematic structural diagram of an adjustable curved annular catheter provided in one embodiment of the present invention is shown schematically; Figure 4b A schematic diagram of the distribution of the sensors on the annular conduit is schematically given; Figure 4c The schematic diagram of the positioning result of the annular catheter at a certain moment is schematically given. Figure 4a and Figure 4b As shown, the annular catheter has a rod and an annular structure, and two first electrodes 104S1 and 104S2 (i.e., the second site) and a first magnetic field sensor 103P (i.e., the first site) are distributed on the rod of the annular catheter, and another 10 second electrodes 104T are distributed on the ring, denoted as 104T1, 104T2, ... (i.e., the third site), and the spatial distances between the first magnetic field sensor 103P and the first electrodes 104S1 and 104S2 are fixed and known, and are denoted as d' respectively. 104S1 and d' 104S2The positioning system of the present invention can realize the positioning of the electrode to be positioned (the 10 second electrodes 104T distributed on the ring) through limited known information (the position of the first magnetic field sensor 103P and the spatial distance between the first magnetic field sensor 103P and the first electrodes 104S1 and 104S2).

[0153] The loop catheter is passed through the vascular access into the right atrium, and a ten-pole catheter is placed in the coronary sinus. The upper electrode is used as a reference electrode to keep the ten-pole catheter from moving during the entire operation.

[0154] use Figure 1 In the embodiment, electrode patches 102 are attached to 6 positions (R, L, H, F, C and B) on the body surface, and a second magnetic field sensor 103Q is mounted on each electrode patch 102. The combination of every two electrode patches 102 is used as an excitation axis to apply excitation (for example, applying a constant current source of 1 mA), so there are a total of 15 excitation axes (RL, HF, CB, CR, CL, CH, CF, RB, LB, HB, FB, RF, LF, HR and HL).

[0155] In the fitting stage, the catheter tip is moved around in the right atrium to each sub-area by operating the handle 106, and the following data are collected at each sampling time:

[0156] 1. Magnetic field strength at the first magnetic field sensor 103P;

[0157] 2. Magnetic field strength at the six second magnetic field sensors 103Q;

[0158] 3. Voltage information relative to the reference position under 15 excitation states at 12 electrodes, namely, two first electrodes 104S on the rod and ten second electrodes 104T on the ring.

[0159] The controller 40 calculates its position coordinates and direction vector based on the magnetic field strength at the first magnetic field sensor 103P, and calculates its position coordinates based on the magnetic field strength at the second magnetic field sensor 103Q. At a certain sampling time t, Figure 4b The spatial position and unit direction vector of the first magnetic field sensor 103P can be calculated from the magnetic field strength information measured by the first magnetic field sensor 103P. Assume that the spatial position of the first magnetic field sensor 103P is denoted as P 103 , the unit direction vector is denoted as D 103 , the direction is from the first electrode 104S1 to the first electrode 104S2.

[0160] At this time, the position P of the first electrode 104S1 can be calculated 104S1 for:

[0161] P104S1 =P 103P -D 103P ·d' 104S1

[0162] The position P of the first electrode 104S2 104S2 for:

[0163] P 104S2 =P 103P +D 103P ·d' 104S2

[0164] Where, d' 104S1 represents the spatial distance between the first electrode 104S1 and the first magnetic field sensor 103P, d' 104S2 represents the spatial distance between the first electrode 104S2 and the first magnetic field sensor 103P.

[0165] In addition, each electrode patch 102 has position information (provided by the second magnetic field sensor 103Q at each electrode patch 102), so the distances from 104S1 and 104S2 to the six electrode patches 102 at the current sampling time can be calculated. For convenience, only 104S1 is used as an example in the following calculations. However, as can be understood by those skilled in the art, the information at the two first electrodes 104S can all participate in the fitting calculation.

[0166] At the same time, the voltages measured at the first electrodes 104S1 and 104S2 are U 104S1 and U 104S2 Note that each voltage is a 15×1 vector, corresponding to the voltage values ​​under 15 excitation states.

[0167] Thus, at each sampling moment, for any electrode patch 102, there are 5 excitation states (ie, the combination with the other 5 electrode patches is used as the excitation axis). Assume that the distance between the first electrode 104S1 and the electrode patch 102 is d i , the first electrode 104S1 has 5 voltages v1, v2, ... v5 in these 5 excitation states. Thus, 5 voltage-distance data pairs can be formed. The other electrode patches 102 are similar, so there are 6×5=30 voltage-distance data pairs at a sampling time.

[0168] Please continue to refer to Figure 5 , which schematically gives a schematic diagram of the division of the target area. Figure 5As shown, the cardiac chamber to be located (target area 101) is divided into multiple sub-areas 1011, and the learning catheter is ensured to roam through as many sub-areas 1011 as possible. The learning catheter roams through a moving track 111 in each sub-area 1011, during which voltage-distance data pairs are continuously accumulated. The least squares linear fitting is performed on the accumulated voltage-distance data pairs in the sub-area 1011, and a total of 30 fitting models can be obtained.

[0169] Taking the electrode patch 102H as an example, there are five excitation states related to it: HF, CH, HB, HR and HL. Please refer to Figures 6a to 6e , which schematically shows scatter plots of five voltage-distance data pairs accumulated in a sub-region in a certain fitting stage, corresponding to five excitation states. In each scatter plot, the horizontal axis is the voltage value collected at the first electrode 104S1 under a certain excitation state, and the vertical axis is the distance from the first electrode 104S1 to the electrode patch 102H.

[0170] Next, Figures 6a to 6e The five voltage-distance data pairs in are fitted using least square linear fitting, and the fitting results of each excitation axis are shown in Table 1 below.

[0171] Table 1 Fitting results of each excitation axis

[0172] Excitation axis HF CH HB HR HL Slope -0.010 -0.027 -0.017 -0.012 0.004 Intercept 304.256 350.955 366.886 340.347 350.440 Fitting error 0.176 1.550 1.673 1.837 2.798

[0173] As can be seen from Table 1, among all the five excitation axes of the electrode patch 102H, the data fitting error in the HF excitation state is the smallest, indicating that its linearity is the best. Then, in the next positioning stage, when calculating the distance between the second electrode 104T in the sub-region 1011 and the electrode patch 102H, only the fitting result of the HF axis can be selected for calculation.

[0174] In this way, similar fitting and selection operations are performed on the relevant data of each electrode patch 102 in each sub-region 1011, and the relevant results are stored in the memory, thereby completing the calculation in the fitting stage.

[0175] In the positioning phase, Figure 4b When performing positioning calculation on the second electrode 104T1 to be positioned, assuming that at a certain sampling time, the voltage collected at the second electrode 104T1 is U 104T1 (also a 15×1 vector), then the positioning calculation process of the second electrode 104T1 includes:

[0176] 1. Determine the sub-area 1011 where the annular conduit is currently located according to the location of the first magnetic field sensor 103P;

[0177] 2. Calculate the distance from the second electrode 104T1 to each electrode patch 102 according to the calculation result of the fitting stage in the current sub-region 1011;

[0178] 3. According to the position data of each electrode patch 102 (provided by the second magnetic field sensor 103Q) and the distance data from the second electrode 104T1 to each electrode patch 102, the position information of the second electrode 104T1 can be calculated using the triangulation method.

[0179] Specifically, please refer to Figure 7 , which schematically shows the distance between the second electrode 104T1 (second site) and each electrode patch 102. Figure 7 As shown, there are 6 electrode patches 102H, 102F, 102C, 102B, 102R and 102L, and their position coordinates are given by the second magnetic field sensor 103Q placed at each electrode patch 102. At a certain sampling time, it is assumed that the position coordinates of each electrode patch 102 are:

[0180] 102H: (x1, y1, z1)

[0181] 102F: (x2, y2, z2)

[0182] 102C: (x3,y3,z3)

[0183] 102B: (x4,y4,z4)

[0184] 102R: (x5,y5,z5)

[0185] 102L: (x6,y6,z6)

[0186] Meanwhile, the distances between the second electrode 104T1 to be positioned and each electrode patch 102 are d1, d2,...d6 respectively.

[0187] Assuming that the position coordinates of the second electrode 104T1 to be positioned are (x0, y0, z0), then there are the following equations:

[0188]

[0189] Subtract the following five equations from the first equation in the above system of equations to get:

[0190]

[0191] in:

[0192]

[0193] There are only three unknown quantities x0, y0 and z0 in the above equation group. The coordinate value of the second electrode 104T1 at the sampling time can be obtained by solving the equation group.

[0194] The position calculation process of other second electrodes 104T to be positioned is similar to the position calculation process of the second electrode 104T1 described above, so it will not be described in detail. Thus, by positioning each second electrode 104T, the positioning of the annular catheter in the cardiac cavity can be completed. Figure 4c The shape of the annular conduit on the display unit 108 at a certain moment is shown.

[0195] It should be noted that Figures 4a to 4c The catheter drawn in the figure is only used for the purpose of describing clearly. In fact, the present invention is not limited to the shapes in 4a to 4c, and can also be applied to catheters of other shapes such as balloons or baskets. In addition, it should be noted that although the fitting method used in the example is the least squares linear fitting, as long as a fitting model is first established for the voltage data (measured by a first electrode 104S in response to a certain excitation state) and the distance data between the first electrode 104S and the electrode patch 102 for applying excitation, and then the distance from the second electrode 104T to be located to at least three electrode patches 102 is calculated based on the fitting model, and then the method of calculating the position of the second electrode 104T by using these distance information is within the scope of protection of the present invention.

[0196] In addition, although most of the embodiments described in this article are applied to electrode positioning within the cardiac cavity, as those skilled in the art can understand, the present invention can also be applied to other scenarios, such as neurological surgery, tumor ablation, pulmonary artery angioplasty, and other surgical scenarios that require interventional or implanted devices for invasive diagnosis or treatment.

[0197] It is understandable that in the current field of three-dimensional ECG mapping, high-density mapping analysis is an increasingly important development trend. The realization of high-density mapping is inseparable from high-precision catheter positioning. Among the current catheter positioning technologies, the positioning technology based on the magnetic field has high accuracy but also high cost. The ordinary electrodes used in electric field positioning can obtain the data required to complete the positioning function while completing the mapping, which can effectively reduce the cost. However, the nonlinear distortion of the electric field in the body is relatively strong, making it difficult to guarantee the accuracy. Therefore, most of the technologies used on the market are magnetic and electric dual positioning to control costs while improving positioning accuracy. The present invention is based on the fact that the electric field is approximately linear in a small local range, so the area to be positioned (i.e., the target area) is divided into multiple sub-areas, and then multiple fitting models are established for each sub-area to achieve positioning. Since most of the calculations involved in the present invention are linear, it can not only reduce the computational overhead, but also greatly save the operation time of the early use of the learning catheter.

[0198] Based on the same inventive concept, the present invention also provides an interventional surgery system, comprising the positioning system of the interventional device as described above and the interventional device, wherein the interventional device can be a ring catheter, a balloon catheter or a basket catheter.

[0199] Corresponding to the above-mentioned positioning system of the interventional device, the present invention further provides a positioning method of the interventional device, wherein the interventional device comprises a learning tool and an application tool, wherein the learning tool and the application tool are used to be placed in a target area of ​​a target object, and the positioning method comprises:

[0200] Dividing the target area into a plurality of sub-areas;

[0201] In the fitting stage, the magnetic field strength information of the first point on the learning device synchronously collected in each of the sub-areas, the magnetic field strength information at at least three electrode patches set on the surface of the target object, and the voltage information of the second point on the learning device relative to a reference position under all excitation states are obtained; the spatial position information of the second point is calculated according to the magnetic field strength information of the first point and the spatial distance information between the first point and the second point; and the fitting model for describing the mapping relationship between voltage and distance of each of the sub-areas is obtained according to the voltage information of the second point relative to the reference position under different excitation states and the distance information between the second point and the electrode patch; and

[0202] During the positioning stage, the voltage information of the third site on the application device relative to the reference site, the sub-region information where the application device is located, and the spatial position information of the electrode patch are obtained synchronously under different excitation states, and the spatial position information of the third site is calculated using the fitting model of the corresponding sub-region and the spatial position information of the electrode patch, wherein the spatial position information of the electrode patch is calculated based on the magnetic field strength information at the electrode patch.

[0203] It should be noted that, as can be understood by those skilled in the art, the spatial position information of the second site is first calculated through the magnetic field strength information of the first site to obtain the spatial position and direction information of the first site, and then calculated based on the spatial position and direction information of the first site and the spatial distance information between the first site and the second site. The distance information between the second site and the electrode patch is calculated based on the spatial position information of the second site and the spatial position information of the electrode patch.

[0204] In an exemplary embodiment, the fitting model for describing the mapping relationship between voltage and distance in each of the sub-regions is obtained based on the voltage information of the second site relative to the reference site under different excitation states and the distance information between the second site and the electrode patch, including: the voltage information of the second site relative to the reference site under different excitation states and the distance information between the second site and the electrode patch are combined into a first type of voltage-distance data pair, and fitting is performed to obtain a fitting model for describing the mapping relationship between voltage and distance in each of the sub-regions under different excitation states.

[0205] In an exemplary embodiment, the fitting model for describing the voltage-distance mapping relationship of each sub-region is obtained based on the voltage information of the second site relative to the reference site under different excitation states and the distance information between the second site and the electrode patch, including: for each electrode patch, the voltage information of the second site relative to the reference site under different excitation states related to the electrode patch and the distance information between the second site and the electrode patch are combined into a first type of voltage-distance data pair, and fitting is performed to obtain a fitting model of each electrode patch under different excitation states related to it in each sub-region.

[0206] In an exemplary embodiment, the method of calculating the spatial position information of the third site by using the fitting model of the corresponding sub-region and the spatial position information of the electrode patch includes: calculating the distance information between the third site and the electrode patch by using the fitting model corresponding to the electrode patch of the corresponding sub-region; and calculating the spatial position information of the third site based on the distance information between the third site and the electrode patch and the spatial position information of the electrode patch.

[0207] Furthermore, the calculating the distance information between the third site and the electrode patch using the fitting model corresponding to the electrode patch of the corresponding sub-region includes:

[0208] From all fitting models of the electrode patch in different excitation states related to the electrode patch in the corresponding sub-region, selecting a fitting model that meets a first preset condition as a target fitting model;

[0209] According to the target fitting model, the distance information between the third site and the electrode patch is calculated.

[0210] In an exemplary embodiment, calculating the spatial position information of the third site by using the fitting model of the corresponding sub-region and the spatial position information of the electrode patch includes:

[0211] Selecting at least three electrode patches that meet a second preset condition from all the electrode patches as target electrode patches;

[0212] The fitting model of the corresponding sub-region is used to calculate the distance information between the third site and each of the target electrode patches, and the spatial position information of the third site is calculated according to the spatial position information of each of the target electrode patches.

[0213] Furthermore, the distance information between the third site and each of the target electrode patches is calculated using the fitting model of the corresponding sub-region, including:

[0214] The distance information between the third site and the target electrode patch is calculated using the fitting model corresponding to the target electrode patch in the corresponding sub-region.

[0215] Furthermore, the calculating the distance information between the third site and the target electrode patch using the fitting model corresponding to the target electrode patch of the corresponding sub-region includes:

[0216] The distance information between the third site and the target electrode patch is calculated by using the target fitting model of the target electrode patch in the corresponding sub-region.

[0217] Optionally, the application device further includes a fourth site, and the positioning method further includes:

[0218] During the positioning stage, the magnetic field strength information of the fourth site is obtained, the spatial position and direction information of the fourth site is calculated based on the magnetic field strength information of the fourth site, and the sub-area information where the application device is located is obtained based on the spatial position and direction information of the fourth site.

[0219] Optionally, the application device further includes a fifth site, and the positioning method further includes:

[0220] In the positioning stage, the voltage information of the fifth site relative to the reference site synchronously collected under all excitation states is obtained, the spatial position information of the fifth site is calculated according to the spatial position and direction information of the fourth site and the spatial distance information between the fourth site and the fifth site, and the distance information between the fifth site and the electrode patch is calculated according to the spatial position information of the fifth site and the spatial position information of the electrode patch, and the voltage information of the fifth site relative to the reference site under different excitation states and the distance information between the fifth site and the electrode patch are combined into a second type of voltage-distance data pair, and the second type of voltage-distance data pair is used to update the fitting model of the corresponding sub-area.

[0221] Optionally, the positioning method further includes:

[0222] The voltage information of the third site relative to the reference position under different excitation states and the distance information between the third site and the electrode patch are combined into a third type of voltage-distance data pair, and valid data pairs are screened out from the third type of voltage-distance data pairs, and the valid data pairs are used to update the fitting model of the corresponding sub-area.

[0223] Based on the same inventive concept, the present invention also provides an electronic device, please refer to Figure 8 , which schematically shows a block diagram of an electronic device provided by an embodiment of the present invention. Figure 8 As shown, the electronic device includes a processor 301 and a memory 303 , wherein the memory 303 stores a computer program, and when the computer program is executed by the processor 301 , the above-mentioned method for positioning the interventional device is implemented.

[0224] like Figure 8 As shown, the electronic device also includes a communication interface 302 and a communication bus 304, wherein the processor 301, the communication interface 302, and the memory 303 communicate with each other through the communication bus 304. The communication bus 304 can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus 304 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus. The communication interface 302 is used for communication between the above-mentioned electronic device and other devices.

[0225] The processor 301 referred to in the present invention may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor 301 is the control center of the electronic device, and various interfaces and lines are used to connect various parts of the entire electronic device.

[0226] The memory 303 may be used to store the computer program. The processor 301 implements various functions of the electronic device by running or executing the computer program stored in the memory 303 and calling the data stored in the memory 303 .

[0227] The memory 303 may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0228] The present invention further provides a readable storage medium, wherein the readable storage medium stores a computer program, and when the computer program is executed by a processor, the positioning method of the interventional device described above can be implemented.

[0229] The readable storage medium of the embodiment of the present invention can adopt any combination of one or more computer-readable media. The readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer hard disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this article, a computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, a device or a device or used in combination with it.

[0230] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0231] In summary, compared with the prior art, the positioning system, method, interventional surgery system, electronic device and storage medium of the interventional device provided by the present invention have the following advantages: the present invention divides the target area into multiple sub-areas, and uses a learning device in the fitting stage to obtain a fitting model for each sub-area for describing the mapping relationship between voltage and distance. Then, in the positioning stage, the distance between the third site and the electrode patch on the application device is obtained based on the fitting model of the sub-area where the application device is located. According to the distance between the third site and the electrode patch and the spatial position information of the electrode patch, the position of the third site can be obtained, thereby realizing the positioning of the application device, and further determining the position, direction and shape information of the application device in the target area of ​​the target object. Therefore, the present invention divides the target area into multiple sub-areas, and establishes a fitting model for each sub-area respectively. Since the electric field is linear in a small local range, through these fitting models, the distance between the third site and the electrode patch can be obtained more accurately, thereby realizing the positioning calculation. In addition, since the present invention establishes a fitting model for each sub-area respectively, the calculation amount of fitting is small, which can effectively reduce the calculation amount and save time cost.

[0232] It should be noted that the computer program code for performing the operation of the present invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages-such as Java, Smalltalk, C++, and also conventional procedural programming languages-such as "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network-including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (for example, using an Internet service provider to connect through the Internet).

[0233] It should be noted that the devices and methods disclosed in the embodiments of this article can also be implemented in other ways. The device implementation described above is only schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of this article. In this regard, each box in the flowchart or block diagram can represent a part of a module, program or code, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical function, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented by a dedicated hardware-based system for performing a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0234] In addition, the functional modules in the various embodiments of this document may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0235] The above description is only a description of the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any changes and modifications made by a person skilled in the art in the field of the present invention based on the above disclosure are within the scope of protection of the present invention. Obviously, a person skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations fall within the scope of the present invention and its equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A positioning system for an interventional device, characterized in that: The intervention device includes a learning tool and an application tool, and the learning tool and the application tool are used to be placed in a target area of ​​a target object; The positioning system comprises: a magnetic field generating unit, an excitation control unit, a data acquisition unit and a controller; The magnetic field generating unit is used to generate a magnetic field passing through the target object; The excitation control unit is used to generate an N-axis electric field in the target object by applying excitation between at least three electrode patches arranged on the surface of the target object, where N≥3; The controller is used to divide the target area into a plurality of sub-areas; The data acquisition unit is used to synchronously acquire the magnetic field strength information of the first point on the learning device, the magnetic field strength information at the electrode patch, and the voltage information of the second point on the learning device relative to a reference position under all excitation states in each of the sub-areas during the fitting phase; and synchronously acquire the magnetic field strength information at the electrode patch and the voltage information of the third point on the application device relative to the reference position under all excitation states during the positioning phase; The controller is also used to calculate the spatial position information of the second site in each of the sub-regions in a fitting stage based on the magnetic field strength information of the first site and the spatial distance information between the first site and the second site, and obtain a fitting model for each of the sub-regions for describing the mapping relationship between voltage and distance based on the voltage information of the second site relative to the reference site under different excitation states and the distance information between the second site and the electrode patch; and, in a positioning stage, calculate the spatial position information of the third site based on the voltage information of the third site relative to the reference site under different excitation states and the sub-region information where the application device is located, using the fitting model of the corresponding sub-region and the spatial position information of the electrode patch, wherein the spatial position information of the electrode patch is calculated based on the magnetic field strength information at the electrode patch.

2. The positioning system for an interventional device according to claim 1, characterized in that: The controller is used to combine the voltage information of the second site relative to the reference position under different excitation states and the distance information between the second site and the electrode patch into a first type of voltage-distance data pair, and perform fitting to obtain a fitting model for describing the mapping relationship between voltage and distance under different excitation states in each of the sub-areas.

3. The positioning system for an interventional device according to claim 1, characterized in that: The controller is used to calculate the distance information between the third site and at least three of the electrode patches using the fitting model under different excitation states in the corresponding sub-area, and calculate the spatial position information of the third site based on the distance information between the third site and the at least three electrode patches and the spatial position information of the at least three electrode patches.

4. The positioning system for an interventional device according to claim 1, characterized in that: The controller is used for, in a fitting stage, for each of the electrode patches, composing voltage information of the second position relative to the reference position under different excitation states related to the electrode patch and distance information between the second position and the electrode patch into a first type of voltage-distance data pair, and performing fitting to obtain a fitting model of each of the electrode patches under different excitation states related to the electrode patch in each of the sub-regions; and In the positioning stage, the distance information between the third site and the electrode patch is calculated using the fitting model corresponding to the electrode patch in the sub-region where the application device is located.

5. The positioning system for an interventional device according to claim 4, characterized in that: The controller is used to select a fitting model that meets a first preset condition from all fitting models of the electrode patch under different excitation states related to the electrode patch as a target fitting model, and calculate the distance information between the third site and the electrode patch based on the target fitting model.

6. The positioning system for an interventional device according to claim 1, characterized in that: The controller is used to select at least three electrode patches that meet the second preset condition from all the electrode patches as target electrode patches, use the fitting model of the sub-area where the application device is located to calculate the distance information between the third site and each of the target electrode patches, and calculate the spatial position information of the third site based on the spatial position information of each of the target electrode patches.

7. The positioning system for an interventional device according to claim 1, characterized in that: The application device also includes a fourth site; The data acquisition unit is also used to collect magnetic field strength information of the fourth position during the positioning stage; The controller is also used to calculate the spatial position and direction information of the fourth position according to the magnetic field strength information of the fourth position during the positioning stage, and obtain the sub-area information where the application device is located according to the spatial position and direction information of the fourth position.

8. The positioning system for an interventional device according to claim 7, characterized in that: The application device is also provided with a fifth site; The data acquisition unit is also used to synchronously acquire voltage information of the fifth position relative to the reference position under all excitation states during the positioning stage; The controller is also used to calculate the spatial position information of the fifth site according to the spatial position and direction information of the fourth site and the spatial distance information between the fourth site and the fifth site during the positioning stage, and calculate the distance information between the fifth site and the electrode patch according to the spatial position information of the fifth site and the spatial position information of the electrode patch, and to form a second type of voltage-distance data pair by combining the voltage information of the fifth site relative to the reference position under different excitation states and the distance information between the fifth site and the electrode patch, and use the second type of voltage-distance data pair to update the fitting model of the corresponding sub-area.

9. The positioning system for an interventional device according to claim 8, characterized in that: The learning tool and the application tool are the same tool, the fourth site and the first site are the same site, and the fifth site and the second site are the same site.

10. The positioning system of an interventional device according to claim 1, characterized in that: The controller is also used to combine the voltage information of the third site relative to the reference site under different excitation states and the distance information between the third site and the electrode patch into a third type of voltage-distance data pair, and to filter out valid data pairs from the third type of voltage-distance data pairs, and use the valid data pairs to update the fitting model of the corresponding sub-area.

11. The positioning system of an interventional device according to claim 1, characterized in that: The excitation control unit is used to apply excitation between the at least three electrode patches and perform high-speed switching among all excitation states in a continuous cycle, and the data acquisition unit acquires voltage information of the second site and the third site relative to the reference position under all excitation states; or The excitation control unit is used to apply excitation between the at least three electrode patches simultaneously, but the frequencies of the applied excitations are different from each other, and the data acquisition unit collects the voltage information of the second site and the third site relative to the reference site and performs filtering processing to obtain the voltage information of the second site and the third site relative to the reference site under all excitation states; or The excitation control unit is used to apply excitation between the at least three electrode patches at the same time, but the frequencies of the applied excitation are different. The data acquisition unit collects voltage information of the second site and the third site relative to the reference position. The controller is used to filter the voltage information of the second site and the third site relative to the reference position collected by the data acquisition unit to obtain the voltage information of the second site and the third site relative to the reference position under all excitation states.

12. The positioning system of an interventional device according to claim 1, characterized in that: It also includes a communication control unit for connecting the controller and the magnetic field generating unit, the excitation control unit, and the data acquisition unit to control communication and data transmission between the controller and the magnetic field generating unit, the excitation control unit, and the data acquisition unit.

13. The positioning system of an interventional device according to claim 1, characterized in that: It also includes a display unit that is communicatively connected to the controller, and the display unit is used to display the position, direction, shape and / or movement trajectory of the learning tool and / or the application tool in the target object.

14. The positioning system of an interventional device according to claim 1, characterized in that: The first location is provided with a first magnetic field sensor, the electrode patch is provided with a second magnetic field sensor, the data acquisition unit acquires magnetic field intensity information of the first location through the first magnetic field sensor, and acquires magnetic field intensity information at the electrode patch through the second magnetic field sensor; The second site is provided with a first voltage sensor, and the third site is provided with a second voltage sensor. The data acquisition unit acquires voltage information of the second site relative to the reference site through the first voltage sensor, and acquires voltage information of the third site relative to the reference site through the second voltage sensor.

15. An interventional surgery system, characterized in that: The invention comprises a positioning system for an interventional device according to any one of claims 1 to 14 and the interventional device.

16. A method for positioning an interventional device, characterized in that: The intervention device includes a learning tool and an application tool, and the learning tool and the application tool are used to be placed in a target area of ​​a target object. The positioning method includes: Dividing the target area into a plurality of sub-areas; In the fitting stage, the magnetic field strength information of the first point on the learning device synchronously collected in each of the sub-areas, the magnetic field strength information at at least three electrode patches set on the surface of the target object, and the voltage information of the second point on the learning device relative to a reference position under all excitation states are obtained; the spatial position information of the second point is calculated according to the magnetic field strength information of the first point and the spatial distance information between the first point and the second point; and the fitting model for describing the mapping relationship between voltage and distance of each of the sub-areas is obtained according to the voltage information of the second point relative to the reference position under different excitation states and the distance information between the second point and the electrode patch; and During the positioning stage, the voltage information of the third site on the application device relative to the reference site, the sub-region information where the application device is located, and the spatial position information of the electrode patch, which are synchronously collected under different excitation states, are obtained, and the spatial position information of the third site is calculated using the fitting model of the corresponding sub-region and the spatial position information of the electrode patch, wherein the spatial position information of the electrode patch is calculated based on the magnetic field strength information at the electrode patch.

17. The method for positioning an interventional device according to claim 16, characterized in that: The method of obtaining a fitting model for describing a voltage-distance mapping relationship in each sub-region according to voltage information of the second site relative to the reference site under different excitation states and distance information between the second site and the electrode patch comprises: The voltage information of the second site relative to the reference position under different excitation states and the distance information between the second site and the electrode patch are combined into a first type of voltage-distance data pair, and fitting is performed to obtain a fitting model for describing the mapping relationship between voltage and distance under different excitation states in each sub-area.

18. The method for positioning an interventional device according to claim 16, characterized in that: The method of obtaining a fitting model for describing a voltage-distance mapping relationship in each sub-region according to voltage information of the second site relative to the reference site under different excitation states and distance information between the second site and the electrode patch comprises: For each of the electrode patches, the voltage information of the second site relative to the reference position under different excitation states associated with the electrode patch and the distance information between the second site and the electrode patch are combined into a first type of voltage-distance data pair, and fitting is performed to obtain a fitting model for each of the electrode patches under different excitation states associated with it in each of the sub-areas.

19. The method for positioning an interventional device according to claim 18, characterized in that: The calculating the spatial position information of the third site by using the fitting model of the corresponding sub-region and the spatial position information of the electrode patch includes: The distance information between the third site and the electrode patch is calculated using the fitting model corresponding to the electrode patch of the corresponding sub-region; The spatial position information of the third site is calculated according to the distance information between the third site and the electrode patch and the spatial position information of the electrode patch.

20. The method for positioning an interventional device according to claim 19, characterized in that: The calculating the distance information between the third site and the electrode patch using the fitting model corresponding to the electrode patch of the corresponding sub-region includes: From all fitting models of the electrode patch in different excitation states related to the electrode patch in the corresponding sub-region, selecting a fitting model that meets a first preset condition as a target fitting model; According to the target fitting model, the distance information between the third site and the electrode patch is calculated.

21. The method for positioning an interventional device according to claim 16, characterized in that: The calculating the spatial position information of the third site by using the fitting model of the corresponding sub-region and the spatial position information of the electrode patch includes: Selecting at least three electrode patches that meet a second preset condition from all the electrode patches as target electrode patches; The fitting model of the corresponding sub-region is used to calculate the distance information between the third site and each of the target electrode patches, and the spatial position information of the third site is calculated according to the spatial position information of each of the target electrode patches.

22. The method for positioning an interventional device according to claim 16, characterized in that: The application device also includes a fourth site, and the positioning method further includes: During the positioning stage, the magnetic field strength information of the fourth site is obtained, the spatial position and direction information of the fourth site is calculated based on the magnetic field strength information of the fourth site, and the sub-area information where the application device is located is obtained based on the spatial position and direction information of the fourth site.

23. The method for positioning an interventional device according to claim 22, characterized in that: The application device also includes a fifth site, and the positioning method further includes: In the positioning stage, the voltage information of the fifth site relative to the reference site synchronously collected under all excitation states is obtained, the spatial position information of the fifth site is calculated according to the spatial position and direction information of the fourth site and the spatial distance information between the fourth site and the fifth site, and the distance information between the fifth site and the electrode patch is calculated according to the spatial position information of the fifth site and the spatial position information of the electrode patch, and the voltage information of the fifth site relative to the reference site under different excitation states and the distance information between the fifth site and the electrode patch are combined into a second type of voltage-distance data pair, and the second type of voltage-distance data pair is used to update the fitting model of the corresponding sub-area.

24. The method for positioning an interventional device according to claim 16, characterized in that: The positioning method further includes: The voltage information of the third site relative to the reference position under different excitation states and the distance information between the third site and the electrode patch are combined into a third type of voltage-distance data pair, and valid data pairs are screened out from the third type of voltage-distance data pairs, and the valid data pairs are used to update the fitting model of the corresponding sub-area.

25. An electronic device, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the method for positioning the interventional device according to any one of claims 16 to 24 is implemented.

26. A readable storage medium, characterized in that: The readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for positioning the interventional device according to any one of claims 16 to 24 is implemented.

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