A three-dimensional ultrasonic reconstruction probe based on an acousto-optic positioning system

Abstract

The application provides a three-dimensional ultrasonic reconstruction probe based on an acousto-optic positioning system, which comprises an embedded host computer, an ultrasonic imaging module, an acousto-optic positioning system and a positioning handle; the ultrasonic imaging module is used for acquiring a two-dimensional ultrasonic image sequence; the acousto-optic positioning system is used for acquiring pose information of each two-dimensional ultrasonic image; and the embedded host computer is provided with a display module used for displaying a three-dimensional ultrasonic image. The sound wave of the three-dimensional ultrasonic reconstruction probe based on the acousto-optic positioning system is not blocked, and the probe can compensate for the deficiency of an optical sensor in some special occasions; compared with other three-dimensional positioning technologies, the technology is basically not affected by the external environment.

Description

Technical Field

[0001] This invention belongs to the field of three-dimensional ultrasound imaging technology, and specifically relates to a three-dimensional ultrasound reconstruction probe based on an acousto-optic positioning system. Background Technology

[0002] In the field of 3D ultrasound imaging, free-arm 3D imaging technology uses a traditional 2D ultrasound probe that can be freely moved in space to scan a target object. This is combined with 3D spatial sensing technology to obtain the probe's spatial position and attitude information. Currently, commonly used 3D spatial sensing technologies mainly involve fixing a positioning device receiver to the holding end of the ultrasound probe, along with a spatial positioning signal transmitter, to perform 3D scanning and imaging of the target object, thus upgrading 2D ultrasound equipment to 3D ultrasound equipment. Examples include determining probe position and attitude based on changes in electromagnetic field strength, using optical sensors and cameras to detect probe position and pose, and using multi-axis spatial attitude sensors or inertial navigation devices to locate probe position and pose. However, these commonly used 3D spatial sensing technologies all suffer from the following drawbacks: electromagnetic field strength is easily affected by external electromagnetic interference; optical sensors are susceptible to light obstruction; and attitude sensors and inertial navigation devices lack an external fixed coordinate system as a positioning reference, easily leading to accumulated errors. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a three-dimensional ultrasound reconstruction probe based on an acoustic-optical positioning system. Based on the pose data output by two sensors, acoustic and optical, a spatial positioning coordinate system is established. The spatial position and orientation of the ultrasound probe are calculated based on geometric relationships to realize the three-dimensional reconstruction of two-dimensional ultrasound images. The technical solution of this invention includes a positioning handle, an embedded host computer, an ultrasound imaging module that communicates wirelessly with the embedded host computer, and an acoustic-optical positioning system.

[0004] The ultrasound imaging module is used to acquire two-dimensional ultrasound image sequences, and the ultrasound imaging module includes a B-mode ultrasound probe disposed on the positioning handle;

[0005] The acoustic-optic positioning system is used to acquire the position and orientation information of the ultrasound probe. The acoustic-optic positioning system includes a positioning host and a spherical positioning receiver located on the positioning handle. The positioning host and the spherical positioning receiver communicate wirelessly.

[0006] The embedded host computer is equipped with a display module for displaying three-dimensional ultrasound images.

[0007] The three-dimensional ultrasonic reconstruction probe based on the acousto-optic positioning system of this invention has the following beneficial effects:

[0008] Sound waves are unobstructed and can compensate for the shortcomings of optical sensors in certain special situations. Compared with other 3D positioning technologies, this technology is largely unaffected by the external environment. The positioning handle has a high degree of integration, is small in size, and the positioning host is easy and quick to deploy. Attached Figure Description

[0009] Figure 1 A schematic diagram of one implementation method;

[0010] Figure 2 A positioning handle according to a specific embodiment;

[0011] Figure 3 A schematic diagram of the spatial geometric relationship between a spherical positioning receiver and an ultrasound probe according to a specific embodiment;

[0012] Figure 4 A schematic diagram illustrating one implementation method. Detailed Implementation

[0013] The following embodiments further illustrate the content of the present invention, but should not be construed as limiting the present invention. Any modifications or substitutions made to the methods, steps, or conditions of the present invention without departing from the spirit and essence of the invention are within the scope of the present invention.

[0014] Some implementations of three-dimensional ultrasonic reconstruction probes based on acousto-optic localization systems, such as Figure 1 As shown, it includes an embedded host computer 1, an ultrasound imaging module 2 that communicates wirelessly with the embedded host computer 1, an acoustic-optical positioning system 3, and a positioning handle 4;

[0015] The ultrasound imaging module 2 is used to acquire two-dimensional ultrasound image sequences. The ultrasound imaging module 2 includes a B-mode ultrasound probe 21 mounted on the positioning handle 4.

[0016] The acoustic-optical positioning system 3 is used to acquire the pose information of each frame of two-dimensional ultrasound image. The acoustic-optical positioning system 3 includes a positioning host 31 and a spherical positioning receiver 32 located on the positioning handle 4. The positioning host 31 and the spherical positioning receiver 32 communicate wirelessly.

[0017] The embedded host computer 1 is equipped with a display module 11 for displaying three-dimensional ultrasound images and a three-dimensional reconstruction module 12. The three-dimensional reconstruction module obtains the pose information and two-dimensional ultrasound image sequence, and calculates the three-dimensional reconstruction of the two-dimensional ultrasound image according to the geometric relationship.

[0018] In some specific implementations, the structure of the positioning handle is as follows: Figure 2 The ultrasound probe is located at the bottom of the positioning handle, and the spherical positioning receiver is located at the top of the positioning handle. A gripping part is provided on the side of the positioning handle between the ultrasound probe and the spherical positioning receiver. Figure 3The distance between the ultrasound probe and the spherical positioning receiver in the vertical direction is fixed as H, and the distance between the ultrasound probe and the spherical positioning receiver in the horizontal projection direction is L.

[0019] In some implementations, the spherical positioning receiver includes an acoustic sensor and an optical sensor that jointly measure the pose information of the ultrasound probe, the pose information including the spatial position coordinates (t) of the ultrasound probe in a Cartesian coordinate system at a certain moment. X ,t y ,t z ), and the normal vector (θ) of the plane containing the two-dimensional ultrasound image acquired at the stated time. x ,θ y ,θ z ).

[0020] The acoustic-optical positioning system acquires pose information through the following steps:

[0021] The positioning host continuously or intermittently emits acoustic positioning signals to the surroundings and records the emission time T1. Multiple sensors on the spherical positioning receiver receive the acoustic positioning signals and record the reception time T2. The distance between the spherical locator and the positioning host is calculated as D = (T2 - T1) × V, where V is the propagation speed of sound waves in the medium.

[0022] The three-dimensional reconstruction module returns the spatial coordinates (t′) to the spherical positioning receiver. x ,t′ y ,t′ z The spatial position coordinates (t) of the ultrasound probe are obtained by correction. x ,t y ,t z Specifically, through the following methods:

[0023] The three-dimensional reconstruction module returns the spatial coordinates (t′) to the spherical positioning receiver. x ,t′ y ,t′ z The correction method is calculated as follows:

[0024] t x =t′ x ;

[0025] t y =t′ y -H;

[0026] t z =t′ z -L;

[0027] Among them, (t) X ,t y ,t z) represents the spatial coordinates of the ultrasound probe, (t′) x ,t′ y ,t′ z ) represents the spatial coordinates returned by the spherical positioning receiver, H is the vertical distance between the ultrasound probe and the spherical positioning receiver, and L is the horizontal projection distance between the ultrasound probe and the spherical positioning receiver.

[0028] Wherein, the normal vector (θ) of the plane containing the two-dimensional ultrasound image x ,θ y ,θ z Calculated using the following method:

[0029] Set a control window with a length of four frames, move the control window starting from the first four frames of the two-dimensional ultrasound image sequence, and complete the following steps within each control window:

[0030] The three points of interest marked on each two-dimensional ultrasound image are designated as the first point of interest (ROI1), the second point of interest (ROI2), and the third point of interest (ROI3).

[0031] Take the i-th point of interest from each of the four frames in the control window, and fit it to the Bézier curve function using the following formula to obtain three Bézier curves B. i (t), i = 1, 2, 3:

[0032]

[0033] Where t is the parameter of the Bézier curve, t∈[0,1], n is the number of control points, and p k Let k be the k-th control point, where k = 1, 2, ..., n; i = 1, 2, 3;

[0034] For each obtained Bézier curve B i (t), i = 1, 2, 3, interpolation is performed between the two interest points on the first frame image and the second frame image, and four interpolation points are taken as p(ij), i = 1, 2, 3; j = 1, 2, 3, 4;

[0035] For the j-th frame image, the normal vector is obtained by taking the vector product of the two vectors formed by the three interpolation points p(1j), p(2j), and p(3j) located on the same plane.

[0036] In a more specific implementation, a one-dimensional array ultrasound probe is used to acquire two-dimensional ultrasound images at the above interpolation points. Four frames are inserted between every two frames of the original low frame rate ultrasound image sequence to obtain a high frame rate two-dimensional ultrasound image sequence.

[0037] In some implementations, when the optical sensor is obstructed, the acoustic sensor provides assistance to ensure positioning accuracy.

[0038] Some implementations of the acoustic-optical positioning system use the PolarTraq positioning module.

[0039] In some implementations, the three-dimensional reconstruction module processes the two-dimensional ultrasound image sequence using a three-dimensional graphics processing algorithm, which includes: a two-dimensional ultrasound image interpolation algorithm and an adaptive histogram equalization algorithm.

[0040] Specific embodiments, such as Figure 4 The ultrasound imaging module includes a positioning handle and an embedded host computer; the positioning handle is used to fix the ultrasound probe and the spherical positioning receiver. The positioning handle performs ultrasound scanning on the region of interest, obtaining a two-dimensional ultrasound image sequence, which is then wirelessly transmitted to the embedded host computer for display. The acoustic-optical positioning system includes a positioning host and a spherical positioning receiver.

[0041] The positioning host receives the spatial position and orientation of each frame of ultrasound image. Two sensors on the spherical positioning receiver, one acoustic signal and one optical sensor, are used to measure the spatial coordinates of the ultrasound probe in the Cartesian coordinate system at a given moment, as well as the normal vector of the plane containing the current ultrasound image and the angle information of the three coordinate axes. Acoustic positioning calculates the distance by combining the time elapsed from the emitted sound wave to the received echo from the object with the speed of sound. By installing multiple acoustic transmitters facing different directions on the positioning handle, strong anti-interference performance can be achieved; acoustic waves can provide effective assistance when the optical sensor is blocked. During this process, the positioning host continuously or intermittently emits acoustic positioning signals to the surroundings, recording the emission time T1. Multiple sensors on the spherical positioning receiver receive the acoustic positioning signals and record the reception time T2. The distance between the spherical positioning receiver and the positioning host is calculated as D = (T2 - T1) × V, where V is the speed of sound in the medium.

[0042] In this embodiment, the acousto-optic localization system uses the PolarTraq localization module. This module is based on acousto-optic hybrid localization technology and has the advantages of high cost-effectiveness, low power consumption, and high portability, while also possessing millimeter-level accuracy and low latency. The acousto-optic localization system is integrated into the ultrasound probe. When the probe scans the region of interest of the target, it can obtain the pose of each two-dimensional ultrasound image.

[0043] In this embodiment, although the spherical positioning receiver and the ultrasound probe are both fixed on the positioning handle, there is a certain geometric relationship between them in space. Therefore, the returned coordinates (t′x, t′y, t′z) need to be converted to obtain the true coordinates (tx, ty, tz) of the ultrasound image. In this embodiment, the calculation method for the coordinates (t′x, t′y, t′z) returned by the spherical positioning receiver to the true coordinates (tx, ty, tz) of the ultrasound image is as follows:

[0044] tX = t′x;

[0045] ty = t′yH;

[0046] tz=t′zL;

[0047] Given the current ultrasound image normal vector and the angle information of the three coordinate axes (θx, θy, θz), the two-dimensional ultrasound image can be arranged in three-dimensional space to obtain a three-dimensional ultrasound image.

[0048] The embodiments and functional operations of the subject matter described in this specification can be implemented in the following ways: digital electronic circuits, tangibly implemented computer software or firmware, computer hardware, including the structures disclosed in this specification and their equivalents, or combinations thereof. Embodiments of the subject matter described in this specification can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on one or more tangible, non-transitory program carriers, for execution by a data processing device or to control the operation of the data processing device. Alternatively or additionally, the program instructions can be encoded on artificially generated propagation signals, such as machine-generated electrical signals, optical signals, or electromagnetic signals, which are generated as encoded information to be transmitted to an appropriate receiver device executed by the data processing device. The computer storage medium can be a machine-readable storage device, a machine-readable storage substrate, a random or serial access memory device, or one or more combinations thereof.

[0049] The term "data processing device" encompasses all kinds of devices, apparatuses, and machines used for processing data, including, for example, programmable processors, computers, or multiprocessor systems or multicomputer systems. Devices may include special-purpose logic circuitry, such as FPGAs (Field-Programmable Gate Arrays) or ASICs (Application-Specific Integrated Circuits). In addition to hardware, devices may also include code that creates the execution environment for associated computer programs, such as processor firmware, protocol stacks, database management systems, operating systems, or combinations thereof.

[0050] While this specification contains numerous specific implementation details, these should not be construed as limiting the scope of any invention or the scope of the claims, but rather as descriptions of features that can embody specific embodiments of a particular invention. Specific features described in this specification within the context of an independent embodiment may also be implemented in combination with a single embodiment. Conversely, various features described within the context of a single embodiment may also be implemented independently in multiple embodiments, or in any suitable sub-combination. Furthermore, while features may be described for combination and even initially claimed in this way, one or more features from a claimed combination may be removed from that combination in some cases, and the claimed combination may be redirected to a sub-combination or a variation thereof.

[0051] Although the present invention has been described in detail above with general descriptions, specific embodiments, and experiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A three-dimensional ultrasonic reconstruction probe based on an acousto-optic localization system, characterized in that, It includes an embedded host computer, an ultrasonic imaging module and an acousto-optic positioning system that communicate wirelessly with the embedded host computer, and a positioning handle; The ultrasound imaging module is used to acquire two-dimensional ultrasound image sequences, and the ultrasound imaging module includes a B-mode ultrasound probe disposed on the positioning handle; The acoustic-optic positioning system is used to acquire the pose information of each frame of two-dimensional ultrasound image. The acoustic-optic positioning system includes a positioning host and a spherical positioning receiver located on the positioning handle. The positioning host and the spherical positioning receiver communicate wirelessly. The embedded host computer is equipped with a display module for displaying three-dimensional ultrasound images; The normal vector (θ) of the plane containing the two-dimensional ultrasound image x ,θ y ,θ z The calculation is performed as follows: a control window with a length of four frames is set, the control window is moved starting from the first four frames of the two-dimensional ultrasound image sequence, and the following steps are performed in each control window: the three points of interest marked on each two-dimensional ultrasound image are the first point of interest ROI1, the second point of interest ROI2 and the third point of interest ROI3. Take the i-th point of interest from each of the four frames in the control window, and fit it to the Bézier curve function using the following formula to obtain three Bézier curves B. i (t), i = 1, 2, 3: Where t is the parameter of the Bézier curve, t∈[0,1], n is the number of control points, and p k Let k be the k-th control point, where k = 1, 2, ..., n; i = 1, 2, 3; For each obtained Bézier curve B i (t), i = 1, 2, 3, interpolation is performed between the two interest points on the first frame image and the second frame image, and four interpolation points are taken as p(ij), i = 1, 2, 3; j = 1, 2, 3, 4; For the j-th frame image, the normal vector is obtained by taking the vector product of the two vectors formed by the three interpolation points p(1j), p(2j), and p(3j) located on the same plane.

2. The three-dimensional ultrasonic reconstruction probe based on an acousto-optic positioning system as described in claim 1, characterized in that, The embedded host computer is equipped with a three-dimensional reconstruction module. The three-dimensional reconstruction module acquires the pose information and the two-dimensional ultrasound image sequence, and calculates the three-dimensional reconstruction of the two-dimensional ultrasound image based on geometric relationships.

3. The three-dimensional ultrasonic reconstruction probe based on an acousto-optic positioning system as described in claim 2, characterized in that, The bottom end of the positioning handle is provided with the ultrasound probe, the top end of the positioning handle is provided with the spherical positioning receiver, and the side of the positioning handle between the ultrasound probe and the spherical positioning receiver is provided with a gripping part.

4. The three-dimensional ultrasonic reconstruction probe based on an acousto-optic positioning system as described in claim 3, characterized in that, The spherical positioning receiver includes an acoustic sensor and an optical sensor that work together to measure the pose information of the ultrasound probe, the pose information including the spatial position coordinates (t) of the ultrasound probe in a Cartesian coordinate system at a certain moment. X ,t y ,t z ), and the normal vector (θ) of the plane containing the two-dimensional ultrasound image acquired at the stated time. x ,θ y ,θ z ).

5. The three-dimensional ultrasonic reconstruction probe based on an acousto-optic positioning system as described in claim 4, characterized in that, When the optical sensor is blocked, the acoustic sensor provides assistance to ensure positioning accuracy.

6. The three-dimensional ultrasonic reconstruction probe based on an acousto-optic positioning system as described in claim 4, characterized in that, The acoustic-optical positioning system acquires pose information through the following steps: The positioning host continuously or intermittently emits acoustic positioning signals to the surroundings and records the emission time T1. Multiple sensors on the spherical positioning receiver receive the acoustic positioning signals and record the reception time T2. The distance between the spherical locator and the positioning host is calculated as D = (T2 - T1) × V, where V is the propagation speed of sound waves in the medium. The 3D reconstruction module corrects the spatial coordinates (t′x, t′y, t′z) returned by the spherical positioning receiver to obtain the spatial position coordinates (t′x, t′y, t′z) of the ultrasound probe. X ,t y ,t z ).

7. The three-dimensional ultrasonic reconstruction probe based on an acousto-optic positioning system as described in claim 6, characterized in that, The vertical distance between the ultrasound probe and the spherical positioning receiver is fixed at H, and the horizontal projection distance between them is L. The method by which the three-dimensional reconstruction module corrects the spatial coordinates (t′x, t′y, t′z) returned by the spherical positioning receiver is calculated as follows: t X =t′x; t y =t′y-H; t z =t′z-L; Where (tX,ty,tz) are the spatial coordinates of the ultrasound probe, (t′x,t′y,t′z) are the spatial coordinates returned by the spherical positioning receiver, H is the vertical distance between the ultrasound probe and the spherical positioning receiver, and L is the horizontal projection distance between the ultrasound probe and the spherical positioning receiver.

8. The three-dimensional ultrasonic reconstruction probe based on an acousto-optic positioning system as described in claim 1, characterized in that, The acoustic-optical positioning system uses the PolarTraq positioning module.

9. The three-dimensional ultrasonic reconstruction probe based on an acousto-optic positioning system as described in claim 2, characterized in that, The three-dimensional reconstruction module processes the two-dimensional ultrasound image sequence using a three-dimensional graphics processing algorithm, which includes: a two-dimensional ultrasound image interpolation algorithm and an adaptive histogram equalization algorithm.

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