CN116421217A - Electromagnetic positioning sensor pose calibration method, system and device - Google Patents
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Abstract
The invention provides a pose calibration method, a system and a device of an electromagnetic positioning sensor, which comprises three parts of information acquisition, calibration matrix fitting and three-dimensional space coordinate transformation, wherein the electromagnetic positioning sensor device comprises B-type ultrasonic equipment, an electromagnetic positioning induction sensor, a B-ultrasonic probe, ultrasonic phantom equipment, an electromagnetic positioning calculation unit and a magnetic field generator, wherein the electromagnetic induction sensor is embedded into the B-ultrasonic two-dimensional ultrasonic probe; the coordinate position and the rotation angle of each pixel of the ultrasonic image in the real three-dimensional space are endowed, and then the three-dimensional model represented in the three-dimensional space is the model in the real three-dimensional space.
Description
Technical Field
The invention relates to the field of medical equipment, in particular to a method, a system and a device for calibrating the pose of an electromagnetic positioning sensor.
Background
B-mode ultrasound is the most commonly used ultrasound, and is a two-dimensional sound image map with any orientation obtained by scanning parts such as organs and tissues of a human body through an ultrasonic probe. Based on anatomical morphology, the acoustic impedance difference between various tissue structures reflects echoes and their intensities in terms of gray scale between light (white) and dark (black), so as to display the morphological profile, size and physical properties of tissue organs and lesions.
In the prior art, the B ultrasonic is a two-dimensional sound image obtained from any direction, so that a three-dimensional space image of parts such as human organs cannot be constructed. The existing ultrasonic three-dimensional imaging is to acquire a human organ cross orthogonal anatomical image through a three-dimensional ultrasonic probe, and construct three-dimensional modeling of parts such as organs through a three-dimensional simulation algorithm. Whether two-dimensional ultrasound or three-dimensional ultrasound is adopted, the acquisition azimuth of an ultrasound image is unknown, namely the same kind of ultrasound section, and the position and the angle of an ultrasound probe are different due to acquisition by different doctors or acquisition by the same doctor for a plurality of times, so that the acquisition of the ultrasound image in the conventional scheme can lead to the fact that three-dimensional modeling of algorithm simulation is not repeatable.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a pose calibration method, a pose calibration system and a pose calibration device for an electromagnetic positioning sensor, so as to solve the problems in the background art.
In order to achieve the above object, the present invention is realized by the following technical scheme: the electromagnetic positioning sensor pose calibration method comprises three parts of information acquisition, calibration matrix fitting and conversion of three-dimensional space coordinates, wherein the information acquisition process is realized by a section-based information acquisition method, the process uses a two-dimensional B ultrasonic probe section as a basic acquisition unit, ultrasonic parameters, two-dimensional section images and three-dimensional space position information of an electromagnetic induction sensor can be obtained through scanning under different angles, and the three-dimensional space position information can be stored and processed; in the process of fitting the calibration matrix, a method of fitting a standard ellipsoidal model is adopted, and a fitting result of the calibration matrix is obtained through calculating and fitting offset and average error between the two; the three-dimensional space coordinates are obtained by converting and calculating two-dimensional pixel coordinates, the calculation logic is mainly converted into an ultrasonic probe coordinate system from a pixel coordinate system, then converted into an electromagnetic probe coordinate system from an ultrasonic probe coordinate system, and then converted into an electromagnetic transmitter coordinate system from an electromagnetic probe coordinate system.
Further, the information acquisition includes the following steps: (1) Acquiring ultrasonic image parameters, namely image parameters, an image origin and a corresponding relation between an image and a three-dimensional space; (2) acquiring image data of a slice; (3) acquiring the pixel origin of the section; (4) And acquiring three-dimensional information of the electromagnetic induction sensor corresponding to the tangential plane.
Further, in the step (1), the image parameters acquired by ultrasound include pixel size, brightness, contrast and the like of an ultrasound acquired image, and the parameters are acquired by acquiring corresponding ultrasound video stream information through a B-type ultrasound device; in the step (2), a B ultrasonic probe and a B ultrasonic device are used for acquiring structural information of an object and generating a plurality of section images; in the step (3), an ultrasonic probe transmitting point is taken as a pixel origin of each section, and the pixel origin is used as a pixel coordinate system for standardization; in the step (4), three-dimensional information corresponding to each tangential plane is obtained through electromagnetic induction sensor equipment, wherein the three-dimensional information comprises three-dimensional space information and three-dimensional angle information, and the three-dimensional angle information adopts a quaternion or rotation matrix form.
Further, the calibration matrix fitting includes the steps of: (1) acquiring phantom data; (2) Marking tangential planes, and uniformly dotting on the edge of an ellipsoid on each tangential plane; (3) Calculating an ellipsoid center, calculating pixel coordinates of a labeling point based on the edge of the ellipsoid, and calculating to obtain the center pixel coordinates of the ellipsoid in a weighted average mode; (4) calculating the three-dimensional coordinates and variances of the center of the phantom; (5) iteratively fitting a calibration matrix of the phantom; and (6) optimizing the labeling error.
Further, in the step (2), for labeling of ellipsoids, a method of combining an accurate algorithm with manual labeling is adopted; calculating pixel coordinates of a labeling point based on the edge of the ellipsoid in the center of the ellipsoid, and calculating to obtain center pixel coordinates of the ellipsoid in a weighted average mode; in the step (6), an ellipsoidal curve on each tangent plane is fitted by using a fitting formula of the calibration matrix, and the labeled points with larger errors with the fitted curve are screened and adjusted by an algorithm, and the calibration matrix with higher precision is obtained by recalculating the calibration matrix.
Further, the three-dimensional space coordinate conversion process comprises the following steps: (1) converting the pixel coordinate system into an ultrasonic probe coordinate system: converting the position information from a pixel measurement system into a real three-dimensional coordinate measurement system through pixel origin and aspect pixel space ratio; (2) The ultrasonic probe coordinate system is converted into an electromagnetic probe coordinate system: in the process, coordinates under the coordinate system of the ultrasonic probe are directly multiplied by corresponding transformation; (3) The electromagnetic probe coordinate system is converted into an electromagnetic transmitter coordinate system: the rotation and translation information of the electromagnetic probe, which can be obtained through the electromagnetic sensor, is converted into a corresponding transformation matrix, namely, the rotation and translation of the left-hand multiplication.
The electromagnetic positioning sensor device is applied to the sensor pose calibration method and comprises an electromagnetic induction sensor body, wherein the electromagnetic induction sensor body is matched with an electromagnetic positioning calculation unit and a magnetic field generator, the electromagnetic induction sensor is a six-dimensional measuring sensor, and the six-dimensional measuring sensor comprises coordinate position and rotation angle information, wherein the coordinate pitch yaw angle and roll angle are included.
Furthermore, the electromagnetic induction sensor consists of a group of small coils, can be used as positioning points in the measuring body, and is arranged in a driver slot of the PC case through an electromagnetic positioning calculation unit.
Further, the electromagnetic positioning calculation unit acquires a power supply from the host computer, calculates tracking data of the electromagnetic induction sensor into a three-dimensional space position and a rotation matrix, and is connected with the host computer application program.
The pose calibration system comprises the electromagnetic positioning sensor device, and comprises B-type ultrasonic equipment, an electromagnetic positioning sensor, a B-ultrasonic probe, ultrasonic phantom equipment, an electromagnetic positioning calculation unit and a magnetic field generator, wherein the electromagnetic sensor is embedded into the B-ultrasonic two-dimensional ultrasonic probe, the electromagnetic sensor is embedded into the probe connecting piece in a mode of manufacturing the ultrasonic probe connecting piece, and the surface of the ultrasonic probe of the electromagnetic sensor is fixed.
The invention has the beneficial effects that:
1. the electromagnetic positioning sensor pose calibration method, system and device realize that corresponding real three-dimensional space coordinate position and azimuth angle information including each ultrasonic image pixel can be given to an ultrasonic probe in any azimuth and a corresponding ultrasonic image acquired by the ultrasonic probe; the coordinate position and the rotation angle of each pixel of the ultrasonic image in the real three-dimensional space are endowed, and then the three-dimensional model represented in the three-dimensional space is the model in the real three-dimensional space, and the image acquired by ultrasonic has the authenticity represented in the three-dimensional space.
2. The position and pose calibration method, the position and pose calibration system and the position and pose calibration device for the electromagnetic positioning sensor can accurately capture the position and pose information of the ultrasonic probe corresponding to each ultrasonic tangent plane, so that the relative spatial position relation between different tangent planes is obtained, the three-dimensional space coordinate mapping of ultrasonic images is realized by using a pre-calibrated transformation matrix, the accuracy of the mutual cross representation between the tangent planes is ensured, the three-dimensional reconstruction of ultrasonic data is achieved, and the image acquired by ultrasonic has the repeatability of representation in the three-dimensional space.
3. The method, the system and the device for calibrating the pose of the electromagnetic positioning sensor can be applied to three-dimensional reconstruction of various parts such as different human organs, focuses, tissues and the like, help to obtain three-dimensional space position information required by the three-dimensional reconstruction, and are widely applied.
Drawings
FIG. 1 is a flow chart of a method for calibrating the pose of an electromagnetic positioning sensor according to the present invention;
FIG. 2 is an illustration of acquiring an ultrasound image from a phantom in accordance with an embodiment of the present invention;
FIG. 3 is a schematic diagram of a B-mode ultrasound probe and electromagnetic sensor link according to an embodiment of the present invention;
FIG. 4 is a diagram showing the relative positional relationship between the B-ultrasonic probe and the electromagnetic induction sensor according to the present invention;
FIG. 5 is a schematic diagram of the relationship among the magnetic field generator, the electromagnetic sensor and the coordinate system of the B-ultrasonic probe according to an embodiment of the present invention.
Detailed Description
The invention is further described in connection with the following detailed description, in order to make the technical means, the creation characteristics, the achievement of the purpose and the effect of the invention easy to understand.
Referring to fig. 1 to 5, the present invention provides a technical solution: the method comprises three parts of information acquisition, calibration matrix fitting and conversion of three-dimensional space coordinates.
(1) Information acquisition
In the aspect of spatial information acquisition of any angle based on a B ultrasonic probe, an information acquisition method based on a tangent plane is adopted. The method takes the section of the two-dimensional B ultrasonic probe as a basic acquisition unit, and ultrasonic parameters, two-dimensional section images and three-dimensional space position information of the electromagnetic induction sensor can be obtained through scanning under different angles, and the three-dimensional space position information can be stored and processed. Compared with the traditional full-angle scanning method, the information acquisition method based on the tangent plane can greatly reduce the data volume and the storage cost, can improve the acquisition efficiency and the accuracy of the information, and is more suitable for the requirements of large-scale data acquisition and processing. The specific implementation is as follows:
(1.1) acquiring ultrasonic image parameters, namely image parameters, an image origin and a corresponding relation between the image and a three-dimensional space. The image parameters of the ultrasound acquisition include the pixel size, brightness, contrast, etc. of the ultrasound acquisition image, and these parameters can be obtained by acquiring corresponding ultrasound video stream information by a B-mode ultrasound device, as shown in fig. 2. And the corresponding relation between the image and the three-dimensional space can be obtained by acquiring the corresponding pixel length and the actual space length on the B-type ultrasonic equipment. Specifically, the vertical pixel space ratio p y And a lateral pixel space ratio p x Can be obtained on the image and on the actual screen, respectively, by measuring the distance of the two points. Through the parameters, the corresponding relation between the image pixels and the actual space can be established, so that the accurate positioning of the ultrasonic image in the three-dimensional coordinate system is realized. It is noted that there may be some differences in the pixel size and pixel space ratio of the acquired image for different ultrasound devices, different acquisition modes. Therefore, in comparing and calculating ultrasound images between a plurality of devices, it is necessary to normalize these parameters to ensure accuracyAnd reliability. Meanwhile, the accuracy of the parameter also affects the subsequent data processing and application effects, so that high precision and accuracy are required to be maintained in the acquisition and calculation processes.
(1.2) acquiring image data of the slice. As shown in fig. 2, the B-mode ultrasonic probe and the B-mode ultrasonic device can be used for acquiring structural information of an object and generating a plurality of slice images. In order to better utilize the information of the section images, a method of forming a plurality of section images into a set of data is generally adopted for storage. Thus, the physiological state in the human body can be reflected more comprehensively, and the image processing algorithm is utilized to extract useful indexes; the acquisition of multiple groups of section images can improve the accuracy and reliability of detection. Processing and analysis of the data, such as denoising, smoothing and enhancement, may be added to improve the sharpness and signal-to-noise ratio of the image. Any errors and uncertainties in the acquisition and processing may have an impact on the final result, and therefore a high degree of accuracy and repeatability is required throughout the process.
(1.3) acquiring the pixel origin of the section. The origin of the pixel refers to taking a point on the image that is physically identical as the origin of the pixel coordinate system on each section. We propose to take the ultrasound probe emission point as the pixel origin of each section. The pixel origin can be standardized for a pixel coordinate system, and the pixel coordinates can be calculated conveniently.
And (1.4) acquiring three-dimensional information of the electromagnetic induction sensor corresponding to the tangential plane. The electromagnetic induction sensor is different from an ultrasonic probe, and can acquire three-dimensional information corresponding to each tangential plane, wherein the three-dimensional information comprises three-dimensional space information (x, y, z) and three-dimensional angle information (w, x, y, z). Therefore, the electromagnetic induction sensor and the ultrasonic probe are combined, so that the structure and the lesions in the human body can be more comprehensively and accurately analyzed. Specifically, as shown in fig. 3, by binding the ultrasonic probe and the electromagnetic induction sensor, the electromagnetic induction sensor information corresponding to each section can be easily acquired on the B-type ultrasonic equipment. Then, three-dimensional information corresponding to each tangential plane can be acquired through the electromagnetic induction sensor device, wherein the three-dimensional information comprises three-dimensional space information and three-dimensional angle information. Wherein, three-dimensional angle information is suggested to be in the form of quaternion or rotation matrix for more convenient processing and calculation. After the three-dimensional information corresponding to the tangent plane is obtained, various algorithms and models can be used for data analysis and calculation.
In the present embodiment, it is important to organize data reasonably in medical image data acquisition and analysis. In summary, it is proposed to use a set of data containing an ultrasound image parameter and sets of slice information. Each section of section information comprises a corresponding two-dimensional section image and three-dimensional information of an electromagnetic induction sensor. The data organization mode can more fully utilize the information quantity of the section images and the three-dimensional information, and simultaneously meets the requirements of medical image data management and analysis.
(2) Calibration matrix fitting
The combination form of the two-dimensional B ultrasonic probe and the electromagnetic probe is complex, and the two-dimensional B ultrasonic probe and the electromagnetic probe are directly regarded as a body which can influence the accurate fitting of the calibration matrix. In order to solve the problem, a standard ellipsoidal model fitting method is adopted, and the fitting result of the calibration matrix is obtained by calculating and fitting offset and average error between the two methods. The method can greatly improve the calibration precision and reduce the error. The specific method comprises the following steps:
and (2.1) acquiring phantom data, wherein the implementation details are shown in a first part of the specific technical scheme. The quality and quantity of the acquired phantom data directly affect the imaging effect and the diagnosis accuracy, and according to our research and practical experience, it is suggested to acquire an ultrasonic image parameter and several sets of section information. Specifically, each set of cuts requires more than 30 cuts from 5 windows on the front and side of the phantom. In order to ensure that the distribution of the acquired section is uniform and the image quality is clear and reliable as much as possible, we propose to pay attention to details and specifications, including angles, distances and the like, when acquiring the phantom data. It should be noted that the acquisition of phantom data involves many factors such as human error, time cost, and magnetic field strength, so that the fit data is not as good as the more. For the current situation, we propose to collect 2 groups of sections, 30 sections per group.
And (2.2) marking the tangential planes, and uniformly dotting on the edge of the ellipsoid on each tangential plane. For labeling of ellipsoids, a method of combining an accurate algorithm and manual labeling is required. Specifically, in order to label points on the edge of an ellipsoid, an algorithm is adopted to automatically label and combine manual labeling. After the center of an ellipsoid is selected, uniformly radiating a plurality of rays by taking the center as the center, and labeling the edge of the ellipsoid from an image by adopting an intelligent threshold detection method. Then, manually correcting dotting and increasing dotting modes to further optimize and refine the labeling of the ellipsoidal edge. The method has strong flexibility, can rapidly mark the edges of complex shapes, and can ensure the marking accuracy and reliability. In order to ensure the uniformity of the distribution and the sufficiency of the number of the marking points, we propose that the marking points are distributed as uniformly as possible at the edge of the ellipsoid and the number is not less than 25.
And (2.3) calculating an ellipsoid center, wherein the calculation of the ellipsoid center is based on the pixel coordinates of the labeling points of the ellipsoid edge, and the central pixel coordinates of the ellipsoid are obtained through calculation in a weighted average mode. Let the pixel point of the marked point be (P 1 ,P 2 …P n ) The pixel coordinates of each point are (x i ,y i ). The center pixel coordinates (x, y) of the ellipsoid are calculated by means of weighted average as the center coordinates of the ellipsoid for calculation for further processing and analysis of the ellipsoid.
(2.4) calculating the three-dimensional coordinates and variance of the phantom center. Let the pixel origin point be (o) x ,o y ) The aspect ratio of the pixel space is p x And p y The coordinates of the center pixel of the ellipsoid are (x) 0 ,y 0 ) Unit transformation matrix S with correction matrix 4*4 0 The position coordinates of the magnetic field emitter of the electromagnetic probe are (x, y, z), and the rotation angles are (w, x, y, z). And calculating the true three-dimensional coordinates of the ellipsoid by using the data, wherein specific implementation details are shown in a second part of the specific technical scheme. The new ellipsoidal center coordinate is calculated as (P 1 ,P 2 …P n ) The average ellipsoidal center coordinates are
The variance in the centre of the ellipsoid is +.>
Variance is a statistical indicator that reflects the degree of dispersion of data, and is calculated by calculating the sum of squares of differences between data points and average values. In calibration matrix fitting, the variance can be used to evaluate the accuracy of the fitting. There is a certain difference in ellipsoids in different tangential planes, so for each tangential plane, the variance of the center of the ellipsoid of the corresponding tangential plane needs to be calculated. By calculating the variance of each section, the accuracy of the calibration matrix can be more accurately known and corresponding adjustments made.
(2.5) iteratively fitting a calibration matrix of the phantom. By means of a fitting algorithm, we can fit the measurement data to a standard phantom and derive therefrom as accurate a calibration matrix as possible. Through continuous research and practice, we consider that the Levenberg-Marquarelt fitting algorithm can obtain a high-precision calibration matrix in a short time, and the precision and accuracy of three-dimensional coordinate calculation are greatly improved. The algorithm can be used for calibrating measuring instruments, can be applied to a plurality of other fields, and provides powerful support and guarantee for scientific research and practical application.
(2.6) optimizing the labeling error. Due to the influence of measurement errors and other factors, certain errors may exist in the labeling data. To optimize the accuracy and precision of the annotation data, we can optimize the annotation error by calibrating the matrix. The ellipsoid curve on each tangent plane can be fitted by using a fitting formula of a calibration matrix, and then labeling points with larger errors with the fitted curve can be screened out by an algorithm, so that manual adjustment is required. Therefore, the labeling data can be gradually optimized, and a calibration matrix with higher precision can be obtained by recalculating the calibration matrix.
In this embodiment, since the calibration matrix is only related to the ultrasonic probe, the electromagnetic probe and the human error, the calibration matrix calculated by the standard phantom can be used for any other application scenario, without re-fitting, and high accuracy and robustness are maintained. The method not only can save a great deal of time and labor cost, but also can improve the efficiency and the accuracy of data. By the method, a group of calibration matrixes with high universality and stable precision can be created, and a more reliable data base is brought for scientific research and actual production.
(3) Three-dimensional space coordinate position
By converting and calculating the two-dimensional pixel coordinates into three-dimensional space coordinates, a great amount of expansion and enrichment can be brought to the application space of two-dimensional ultrasound, so that more real coordinates of a tangent plane at any angle can be acquired, and the structure and characteristics of a given object can be more comprehensively known. As shown in fig. 5, the calculation logic is mainly converted from a pixel coordinate system to an ultrasonic probe coordinate system, then from the ultrasonic probe coordinate system to an electromagnetic probe coordinate system, and then from the electromagnetic probe coordinate system to an electromagnetic transmitter coordinate system. The implementation details are as follows:
(3.1) converting the pixel coordinate system into an ultrasonic probe coordinate system. We convert the position information from a pixel measurement system to a true three-dimensional coordinate measurement system and from two dimensions to three dimensions by pixel origin and aspect pixel space ratio. Let arbitrary pixel coordinates be (x) 0 ,y 0 ) The origin of the pixels in the acquired ultrasonic image parameters is (o) x ,o y ) The aspect ratio of the pixel space is p x ,p y . We can see that the z direction of the probe section is 0, and the pixel coordinates correspond to the three-dimensional coordinates ((x) under the ultrasonic probe coordinate system 0 -o x )*p x ,(y 0 -o y )*p y ,0)。
(3.2) converting the ultrasonic probe coordinate system into an electromagnetic probe coordinate system. In the second part of the specific technical scheme, the offset and transformation between the ultrasonic probe and the electromagnetic probe are accurately expressed through the calibration matrix, and the coordinate under the coordinate system of the ultrasonic probe is multiplied by the corresponding transformation. Let the coordinate of any point under the ultrasonic probe coordinate system be P 0 The calibration matrix is S b The corresponding coordinate under the electromagnetic probe coordinate system is S b .P 0 。
(3.3) converting the electromagnetic probe coordinate system into an electromagnetic transmitter coordinate system. Corresponding rotation and translation information conversion of electromagnetic probe obtained through electromagnetic sensorThe transformation matrix, i.e. the left-hand rotation and translation. Let the coordinate of any point under the electromagnetic probe coordinate system be P 0 The corresponding rotation matrix of the electromagnetic probe is S f Translation is t= (x, y, z), transform matrix is
The coordinate under the electromagnetic transmitter is S ff .P 0 。
To sum up, let the pixel shift scaling matrix be S p The calibration matrix is S b The electromagnetic probe transforms the matrix into S from the electromagnetic transmitter ff The ultrasonic pixel coordinate is P 0 = (x, y, 0), true three-dimensional coordinates S ff .S b .S p .P 0 . Ultrasonic imaging can only acquire information of a two-dimensional section, but cannot directly acquire position information of an object in a three-dimensional space. The two-dimensional points on the ultrasonic tangent plane are mapped to the corresponding three-dimensional space coordinates through transformation, so that the positioning and the identification of the ultrasonic in the three-dimensional object are realized. The transformation can be fitted and calculated based on standard body simulation data, so that the effect of accurate mapping is achieved, robustness is achieved, and richer and more accurate data support is provided for medical diagnosis.
While the fundamental and principal features of the invention and advantages of the invention have been shown and described, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing exemplary embodiments, but may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in detail below, and that the embodiments described in the examples may be combined as appropriate to form other embodiments that will be apparent to those skilled in the art.
Claims (10)
1. A method, a system and a device for calibrating the pose of an electromagnetic positioning sensor are characterized in that: the method comprises three parts of information acquisition, calibration matrix fitting and three-dimensional space coordinate transformation, wherein the information acquisition process is realized by an information acquisition method based on a tangent plane, the process takes a two-dimensional B-ultrasonic probe tangent plane as a basic acquisition unit, ultrasonic parameters, two-dimensional tangent plane images and three-dimensional space position information of an electromagnetic induction sensor can be obtained through scanning under different angles, and the three-dimensional space position information can be stored and processed; in the process of fitting the calibration matrix, a method of fitting a standard ellipsoidal model is adopted, and a fitting result of the calibration matrix is obtained through calculating and fitting offset and average error between the two; the three-dimensional space coordinates are obtained by converting and calculating two-dimensional pixel coordinates, the calculation logic is mainly converted into an ultrasonic probe coordinate system from a pixel coordinate system, then converted into an electromagnetic probe coordinate system from an ultrasonic probe coordinate system, and then converted into an electromagnetic transmitter coordinate system from an electromagnetic probe coordinate system.
2. The method for calibrating the pose of the electromagnetic positioning sensor according to claim 1, wherein the method comprises the following steps: the information acquisition comprises the following steps: (1) Acquiring ultrasonic image parameters, namely image parameters, an image origin and a corresponding relation between an image and a three-dimensional space; (2) acquiring image data of a slice; (3) acquiring the pixel origin of the section; (4) And acquiring three-dimensional information of the electromagnetic induction sensor corresponding to the tangential plane.
3. The method for calibrating the pose of the electromagnetic positioning sensor according to claim 2, wherein the method comprises the following steps: in the step (1), the image parameters acquired by ultrasound include pixel size, brightness, contrast and the like of an ultrasound acquisition image, and the parameters are acquired by acquiring corresponding ultrasound video stream information through B-type ultrasound equipment; in the step (2), a B ultrasonic probe and a B ultrasonic device are used for acquiring structural information of an object and generating a plurality of section images; in the step (3), an ultrasonic probe transmitting point is taken as a pixel origin of each section, and the pixel origin is used as a pixel coordinate system for standardization; in the step (4), three-dimensional information corresponding to each tangential plane is obtained through electromagnetic induction sensor equipment, wherein the three-dimensional information comprises three-dimensional space information and three-dimensional angle information, and the three-dimensional angle information adopts a quaternion or rotation matrix form.
4. The method for calibrating the pose of the electromagnetic positioning sensor according to claim 1, wherein the method comprises the following steps: the calibration matrix fitting includes the steps of: (1) acquiring phantom data; (2) Marking tangential planes, and uniformly dotting on the edge of an ellipsoid on each tangential plane; (3) Calculating an ellipsoid center, calculating pixel coordinates of a labeling point based on the edge of the ellipsoid, and calculating to obtain the center pixel coordinates of the ellipsoid in a weighted average mode; (4) calculating the three-dimensional coordinates and variances of the center of the phantom; (5) iteratively fitting a calibration matrix of the phantom; and (6) optimizing the labeling error.
5. The method for calibrating the pose of the electromagnetic positioning sensor according to claim 4, wherein the method comprises the following steps: in the step (2), for the labeling of ellipsoids, a method of combining an accurate algorithm and manual labeling is adopted; calculating pixel coordinates of a labeling point based on the edge of the ellipsoid in the center of the ellipsoid, and calculating to obtain center pixel coordinates of the ellipsoid in a weighted average mode; in the step (6), an ellipsoidal curve on each tangent plane is fitted by using a fitting formula of the calibration matrix, and the labeled points with larger errors with the fitted curve are screened and adjusted by an algorithm, and the calibration matrix with higher precision is obtained by recalculating the calibration matrix.
6. The method for calibrating the pose of the electromagnetic positioning sensor according to claim 1, wherein the method comprises the following steps: the three-dimensional space coordinate conversion process comprises the following steps: (1) converting the pixel coordinate system into an ultrasonic probe coordinate system: converting the position information from a pixel measurement system into a real three-dimensional coordinate measurement system through pixel origin and aspect pixel space ratio; (2) The ultrasonic probe coordinate system is converted into an electromagnetic probe coordinate system: in the process, coordinates under the coordinate system of the ultrasonic probe are directly multiplied by corresponding transformation; (3) The electromagnetic probe coordinate system is converted into an electromagnetic transmitter coordinate system: the rotation and translation information of the electromagnetic probe, which can be obtained through the electromagnetic sensor, is converted into a corresponding transformation matrix, namely, the rotation and translation of the left-hand multiplication.
7. An electromagnetic positioning sensor device, characterized in that: the sensor device is applied to the sensor pose calibration method according to claim 1, and comprises an electromagnetic induction sensor body, wherein the electromagnetic induction sensor body is matched with an electromagnetic positioning calculation unit and a magnetic field generator, the electromagnetic induction sensor is a six-dimensional measuring sensor, and the six-dimensional measuring sensor comprises coordinate position and rotation angle information, wherein the pitch yaw and roll angles are included.
8. An electromagnetic positioning sensor apparatus as set forth in claim 7, wherein: the electromagnetic induction sensor consists of a group of small coils, can be used as positioning points in the measuring body, and is arranged in a driver slot of the PC case through an electromagnetic positioning calculation unit.
9. An electromagnetic positioning sensor apparatus as set forth in claim 8, wherein: the electromagnetic positioning calculation unit acquires power from the host computer, calculates tracking data of the electromagnetic induction sensor into a three-dimensional space position and a rotation matrix, and is connected with a host computer application program.
10. An electromagnetic positioning sensor pose calibration system is characterized in that: the pose calibration system comprises an electromagnetic positioning sensor device part in claim 7, and comprises a B-type ultrasonic device, an electromagnetic positioning induction sensor, a B-ultrasonic probe, an ultrasonic phantom device, an electromagnetic positioning calculation unit and a magnetic field generator, wherein the electromagnetic induction sensor is embedded into the B-ultrasonic two-dimensional ultrasonic probe, the electromagnetic induction sensor is embedded into a probe connecting piece in a mode of manufacturing the ultrasonic probe connecting piece, and the surface of the ultrasonic probe of the electromagnetic induction sensor is fixed.
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