Ultrasonic positioning system for brain tumor surgery

Abstract

The invention discloses an ultrasonic positioning system for brain tumor surgery, belongs to the technical field of medical instruments, and solves the problems that an existing two-dimensional ultrasonic scanner is poor in intuition and cannot clearly display the spatial position of bipolar coagulation forceps tips. The method comprises the following steps: acquiring a two-dimensional ultrasonic image in a brain operation process in real time by a two-dimensional ultrasonic scanner; positioning rigid bodies are respectively fixed on a handle of the two-dimensional ultrasonic scanner and a handle of the bipolar electric coagulation forceps; the infrared optical locator is used for spatially locating the two-dimensional ultrasonic scanner and the bipolar electric coagulation forceps by the locating rigid body; based on this, the spatial position of the extension line of the tip of the bipolar coagulation forceps and the coordinates of the intersection point of the extension line and the spatial area of the two-dimensional ultrasonic image are obtained, a bipolar coagulation forceps model is established by adopting a three-dimensional visualization technology, and the two-dimensional ultrasonic image is obtained according to the spatial area coordinates of the two-dimensional ultrasonic image and the spatial coordinates of the tip of the bipolar coagulation forceps and the extension line of the bipolar coagulation forceps. Establishing a spatial region three-dimensional scene image of the bipolar coagulation forceps and the two-dimensional ultrasonic image; and displaying the three-dimensional scene image. The method is suitable for surgical ultrasonic positioning.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices. Background Art

[0002] Brain tumors are a neurological disease that poses a serious threat to human life and health. Neurosurgery is the most direct and effective treatment for brain tumors, but this procedure places high demands on the surgeon. Not only must the surgeon accurately remove the lesion, but the surgeon must also minimize any additional trauma to the patient. Traditional neurosurgery often relies on the surgeon's surgical experience, making it difficult to accurately locate and remove the lesion. This can lead to deviations in the surgical approach and cause additional harm to the patient. Mastering the technique of localizing intracranial lesions is fundamental to a neurosurgeon's surgical procedures and is crucial to the difficulty and duration of the procedure, as well as the postoperative treatment outcome and complications. Inaccurate lesion localization can damage the patient's functional brain areas and other vital intracranial tissues, or result in incomplete tumor removal. Therefore, accurate localization of intracranial lesions is a crucial issue in neurosurgery.

[0003] Various methods for localizing lesions are based on neuroimaging. A common approach is to use CT / MRI tomographic images to create a three-dimensional reconstruction of the intracranial lesion before surgery, supplemented by an extracranial landmark system, to spatially localize the lesion. The main problem is that after craniotomy, the loss of cerebrospinal fluid often causes the position of the brain within the skull to drift. As a result, the three-dimensional coordinates of the tumor determined by preoperative images are inaccurate, resulting in positioning failure and an inability to accurately guide the surgical procedure.

[0004] The key to accurate brain tumor resection lies in precisely locating the tumor's spatial location. Currently, intraoperative ultrasound is frequently used in brain tumor surgery. Ultrasound is widely used for intraoperative imaging due to its compact size, real-time imaging capabilities, and safety and radiation-free nature. In particular, during brain tumor surgery, in the presence of brain drift, intraoperative ultrasound can image the brain tumor in real time and determine its location within the ultrasound image.

[0005] Currently, two-dimensional ultrasound scanners are commonly used for intraoperative ultrasound in clinical practice. The main problems are as follows:

[0006] 1. Ultrasound images show a cross-section of a brain tumor. Doctors usually need to reconstruct the shape of the brain tumor in their own brains, making the geometric features of the brain tumor unintuitive.

[0007] 2. Since the bipolar electrocoagulation forceps used for brain tumor removal cannot locate the position and direction of its front end in space, it cannot accurately remove the tumor, which can easily cause additional damage to normal brain tissue.

[0008] 3. Bipolar coagulation forceps are difficult to distinguish on ultrasound images, making it difficult for doctors to determine the spatial relationship between the tumor cross-section scanned by the ultrasound image and the bipolar coagulation forceps, and the guidance effect of the ultrasound image is reduced. Summary of the Invention

[0009] The present invention aims to solve the problem that existing two-dimensional ultrasonic scanners have poor intuitiveness and cannot clearly display the spatial position of the bipolar coagulation forceps tip, and now provides an ultrasonic positioning system for brain tumor surgery.

[0010] The ultrasonic positioning system for brain tumor surgery of the present invention comprises a two-dimensional ultrasonic scanner, an infrared optical positioning instrument, multiple positioning rigid bodies, bipolar electrocoagulation forceps, a processor and a display;

[0011] The handle of the two-dimensional ultrasound scanner and the handle of the bipolar electrocoagulation forceps are provided with inherent positioning rigid body 1 and positioning rigid body 2 respectively;

[0012] The two-dimensional ultrasound scanner is used to collect two-dimensional ultrasound images in real time during brain surgery; the two-dimensional ultrasound images include two-dimensional images of brain tumors; and the two-dimensional ultrasound images are sent to a processor;

[0013] The infrared optical positioning device is used to spatially position the positioning rigid body 1 and the positioning rigid body 2; and transmit the spatial positioning information to the processor;

[0014] The processor obtains the spatial position of the bipolar electrocoagulation forceps tip and the handle according to the spatial position of the positioning rigid body 2, and also obtains the spatial position of the bipolar electrocoagulation forceps tip and the handle according to the position of the positioning rigid body 1 and the spatial transformation matrix of the ultrasound image. , obtaining the spatial region coordinates of the two-dimensional ultrasound image;

[0015] The processor simultaneously obtains the spatial position of the extension line of the bipolar coagulation forceps tip based on the spatial position and structure of the bipolar coagulation forceps tip and the handle; and further calculates the coordinates of the intersection of the extension line of the bipolar coagulation forceps tip and the spatial region of the two-dimensional ultrasound image using the spatial region coordinates of the two-dimensional ultrasound image and the spatial position of the extension line of the bipolar coagulation forceps tip;

[0016] The processor also uses three-dimensional visualization technology to establish a bipolar coagulation forceps model, and creates a three-dimensional scene image of the spatial area of ​​the bipolar coagulation forceps and the two-dimensional ultrasound image based on the spatial coordinates of the two-dimensional ultrasound image and the spatial coordinates of the tip of the bipolar coagulation forceps and its extension line; and sends the three-dimensional scene image to the display in real time;

[0017] The display is used to display the three-dimensional scene image.

[0018] Furthermore, in the present invention, the method for obtaining the spatial region coordinates of a two-dimensional ultrasound image is:

[0019] Use a two-dimensional ultrasonic scanner equipped with a positioning rigid body 1 to scan an object in space, obtain the spatial coordinates and image coordinates of multiple points on the object, and substitute the spatial coordinates and image coordinates of more than three points on the object into Formula 1 respectively to establish a system of equations to obtain the spatial transformation matrix between the positioning rigid body 1 and the ultrasonic image. ;

[0020] Formula 1

[0021] in, represents the image coordinates of a point on the ultrasound image, Represents the spatial transformation matrix between the infrared optical positioning device and the positioning rigid body 1; Represents the spatial coordinates of a point;

[0022] The positioning rigid body 1 fixed on the handle of the two-dimensional ultrasonic scanner is positioned by an infrared optical positioning device, and the spatial region coordinates of the two-dimensional ultrasonic image are obtained by combining the positioning rigid body 1 with formula 1.

[0023] Furthermore, in the present invention, the method for obtaining the position of the tip of the bipolar coagulation forceps and the spatial position of its handle is:

[0024] The positioning rigid body 2 fixed on the handle of the bipolar coagulation forceps is positioned by an infrared optical positioning instrument, and the spatial position of the bipolar coagulation forceps tip relative to the rigid body 2 is obtained using formula 2;

[0025] Formula 2

[0026] in, Represents the transformation matrix between the infrared optical locator and the positioning rigid body 2, Indicates the spatial position of the positioning rigid body 2, Indicates the spatial position of the bipolar electrocoagulation forceps tip relative to the steel body 2;

[0027] The straight line on which the handle of the bipolar coagulation forceps is located is obtained by formula 3. The straight line equation of the coordinates (x, y, z) of any point on the long axis of the bipolar coagulation forceps is:

[0028] Formula 3

[0029] Furthermore, in the present invention, the method for obtaining the spatial position coordinates of the extension line of the tip of the bipolar coagulation forceps using the spatial position of the tip of the bipolar coagulation forceps and the spatial position of the handle thereof is:

[0030] Formula 4

[0031] Among them, v x =x2-x1,v y =y2-y1,v z=z2-z1, (x1, y1, z1) and (x2, y2, z2) represent the coordinates of two points on the long axis straight line of the bipolar coagulation forceps, and t represents the slope of the extension line of the coagulation forceps.

[0032] Furthermore, in the present invention, the method for obtaining the intersection point when the extension line of the electrocoagulation forceps intersects the spatial area of ​​the two-dimensional ultrasound image is:

[0033] Formula 1 is used to calculate the spatial coordinates of the upper left vertex, lower left vertex, upper right vertex, and lower right vertex of the ultrasound image. The line connecting the lower left vertex and the lower right vertex is used as the bottom line, and the line connecting the upper right vertex and the lower right vertex is used as the right line. The bottom line vector is (v bx , v by , v bz ), the right side vector is (v ex , v ey , v ez The bottom line and the right side line of the ultrasound image in space constitute the normal vector of the image plane (v px , v py , v pz ):

[0034] Formula 5

[0035] Then, the point normal equation of the ultrasound image plane in space is:

[0036] Formula 6

[0037] Among them, (n x , n y , n z ) represents the spatial coordinate of the upper left corner vertex of the ultrasound image, then Formula 4 and Formula 6 are combined to obtain:

[0038] Formula 7

[0039] After solving for t, substitute t into formula 4 to calculate the spatial coordinates of the intersection point where the extension line of the coagulation forceps intersects the spatial area of ​​the two-dimensional ultrasound image.

[0040] Furthermore, in the present invention, the processor converts the coordinates of the intersection of the extension line of the tip of the bipolar coagulation forceps and the two-dimensional ultrasound image space area into two-dimensional ultrasound image coordinates, and marks the intersection in the two-dimensional ultrasound image.

[0041] Furthermore, in the present invention, the formula for converting the coordinates of the intersection of the extension line of the bipolar coagulation forceps tip and the two-dimensional ultrasound image space area into the two-dimensional ultrasound image coordinates is:

[0042] Formula 8

[0043] in, Represents the coordinates of the intersection of the extension line of the bipolar coagulation forceps and the spatial area of ​​the two-dimensional ultrasound image on the two-dimensional ultrasound image.

[0044] Compared to currently used preoperative 3D image-guided brain tumor surgery methods, the positioning method described in this invention can determine the relative spatial position of the lesion in real time during surgery, avoiding the inaccuracies of preoperative 3D image guidance caused by intraoperative brain drift. Compared to surgical methods guided by intraoperative X-rays or MRI images, this invention utilizes safe, radiation-free, and low-cost ultrasound image guidance, avoiding the ionizing radiation of intraoperative X-rays and the high cost of MRI imaging.

[0045] Compared with the method of using intraoperative two-dimensional ultrasound images to guide surgery, the present invention is based on spatial positioning technology and can intuitively display the spatial position relationship between the ultrasound image and the bipolar coagulation forceps, avoiding the unclear position relationship between the ultrasound image and the bipolar coagulation forceps in the brain tissue; the unclear display of the long axis section of the bipolar coagulation forceps in the brain tissue under the ultrasound image and the complex problems of coplanar operation of the ultrasound image plane and the long axis of the bipolar coagulation forceps. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a schematic diagram of the spatial positioning of the image plane of the ultrasound positioning system for brain tumor surgery;

[0047] Figure 2 Calibrate the model for the intersection;

[0048] Figure 3 It is a positioning tool for infrared locators;

[0049] Figure 4 is the ultrasound image of the intersection;

[0050] Figure 5 A physical diagram of a bipolar electrocoagulation forceps equipped with a positioning rigid body;

[0051] Figure 6 A three-dimensional scene image. DETAILED DESCRIPTION

[0052] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other in the absence of conflict.

[0053] Specific implementation method 1: refer to Figures 1 to 6Specifically describing this embodiment, the ultrasound positioning system for brain tumor surgery described in this embodiment includes a two-dimensional ultrasound scanner 1, an infrared optical positioning device 2, multiple positioning rigid bodies, bipolar electrocoagulation forceps 3, a processor and a display;

[0054] The handle of the two-dimensional ultrasonic scanner 1 and the handle of the bipolar electrocoagulation forceps 3 are respectively provided with a positioning rigid body 1 and a positioning rigid body 2;

[0055] The two-dimensional ultrasonic scanner 1 is used to collect two-dimensional ultrasonic images in real time during brain surgery; the two-dimensional ultrasonic images include two-dimensional images of brain tumors; and the two-dimensional ultrasonic images are sent to a processor;

[0056] The infrared optical positioning device 2 is used to spatially position the positioning rigid body 1 and the positioning rigid body 2; and transmit the spatial positioning information to the processor;

[0057] The processor obtains the spatial position of the tip and handle of the bipolar electrocoagulation forceps 3 according to the spatial position of the positioning rigid body 2, and also obtains the spatial position of the tip and handle of the bipolar electrocoagulation forceps 3 according to the spatial position of the positioning rigid body 1 and the spatial transformation matrix of the ultrasound image. , obtaining the spatial region coordinates of the two-dimensional ultrasound image;

[0058] The processor simultaneously obtains the spatial position of the extension line of the tip of the bipolar coagulation forceps 3 based on the spatial position and structure of the tip and handle of the bipolar coagulation forceps 3; and further calculates the coordinates of the intersection of the extension line of the tip of the bipolar coagulation forceps 3 and the spatial area of ​​the two-dimensional ultrasound image using the spatial area coordinates of the two-dimensional ultrasound image and the spatial position of the extension line of the tip of the bipolar coagulation forceps 3;

[0059] The processor also uses three-dimensional visualization technology to establish a bipolar coagulation forceps model, and creates a three-dimensional scene image of the spatial area of ​​the bipolar coagulation forceps and the two-dimensional ultrasound image based on the spatial coordinates of the two-dimensional ultrasound image and the spatial coordinates of the tip of the bipolar coagulation forceps and its extension line; and sends the three-dimensional scene image to the display in real time;

[0060] The display is used to display the three-dimensional scene image.

[0061] Furthermore, in this embodiment, the method for obtaining the spatial region coordinates of the two-dimensional ultrasound image is:

[0062] Use a two-dimensional ultrasonic scanner 1 equipped with a positioning rigid body 1 to scan an object in space, obtain the spatial coordinates and image coordinates of multiple points on the object, and respectively substitute the spatial coordinates and image coordinates of more than three points on the object into Formula 1 to establish a set of equations to obtain the spatial transformation matrix between the positioning rigid body 1 and the ultrasonic image. ;

[0063] Formula 1

[0064] in, represents the image coordinates of a point on the ultrasound image, Represents the spatial transformation matrix between the infrared optical positioning device 2 and the positioning rigid body 1; Represents the spatial coordinates of a point;

[0065] The positioning rigid body 1 fixed on the handle of the two-dimensional ultrasonic scanner 1 is positioned by the infrared optical positioning device 2, and the spatial region coordinates of the two-dimensional ultrasonic image are obtained by combining the positioning rigid body 1 with formula 1.

[0066] Furthermore, in this embodiment, the method for obtaining the tip position of the bipolar electrocoagulation forceps 3 and the spatial position of its handle is:

[0067] The positioning rigid body 2 fixed on the handle of the bipolar coagulation forceps 3 is positioned by an infrared optical positioning instrument 2, and the spatial position of the tip of the bipolar coagulation forceps 3 relative to the rigid body 2 is obtained using formula 2;

[0068] Formula 2

[0069] in, Represents the transformation matrix between the infrared optical locator and the positioning rigid body 2, Indicates the spatial position of the positioning rigid body 2, Indicates the spatial position of the tip of the bipolar coagulation forceps 3 relative to the steel body 2;

[0070] The straight line where the handle of the bipolar coagulation forceps 3 is located is obtained by formula 3. The straight line equation of the coordinates (x, y, z) of any point on the long axis of the bipolar coagulation forceps 3 is:

[0071] Formula 3

[0072] Furthermore, in this embodiment, the method for obtaining the spatial position coordinates of the extension line of the tip of the bipolar coagulation forceps 3 using the spatial position of the tip of the bipolar coagulation forceps 3 and the spatial position of the handle thereof is:

[0073] Formula 4

[0074] Among them, v x =x2-x1,v y =y2-y1,v z =z2-z1, (x1, y1, z1) and (x2, y2, z2) respectively represent the coordinates of two points on the long axis straight line of the bipolar coagulation forceps 3, and t represents the slope of the extension line of the coagulation forceps.

[0075] Furthermore, in this embodiment, the method for obtaining the intersection point when the extension line of the electrocoagulation forceps intersects the two-dimensional ultrasound image space area is:

[0076] Formula 1 is used to calculate the spatial coordinates of the upper left vertex, lower left vertex, upper right vertex, and lower right vertex of the ultrasound image. The line connecting the lower left vertex and the lower right vertex is used as the bottom line, and the line connecting the upper right vertex and the lower right vertex is used as the right line. The bottom line vector is (v bx , v by , v bz ), the right side vector is (v ex , v ey , v ez The bottom line and the right side line of the ultrasound image in space constitute the normal vector of the image plane (v px , v py , v pz ):

[0077] Formula 5

[0078] Then, the point normal equation of the ultrasound image plane in space is:

[0079] Formula 6

[0080] Among them, (n x , n y , n z ) represents the spatial coordinate of the upper left corner vertex of the ultrasound image, then Formula 4 and Formula 6 are combined to obtain:

[0081] Formula 7

[0082] After solving for t, substitute t into formula 4 to calculate the spatial coordinates of the intersection point where the extension line of the coagulation forceps intersects the spatial area of ​​the two-dimensional ultrasound image.

[0083] Furthermore, in this embodiment, the processor converts the coordinates of the intersection of the extension line of the tip of the bipolar electrocoagulation forceps 3 and the two-dimensional ultrasound image space area into two-dimensional ultrasound image coordinates, and marks the intersection in the two-dimensional ultrasound image.

[0084] Furthermore, in this embodiment, the formula for converting the coordinates of the intersection of the extension line of the bipolar coagulation forceps tip and the two-dimensional ultrasound image space area into the two-dimensional ultrasound image coordinates is:

[0085] Formula 8

[0086] in, Represents the coordinates of the intersection of the extension line of the bipolar coagulation forceps and the spatial area of ​​the two-dimensional ultrasound image on the two-dimensional ultrasound image.

[0087] In the present invention, the specific process during the specific implementation is:

[0088] 1. Spatial positioning of ultrasound images: Infrared optical positioning devices are introduced to determine the spatial position of ultrasound images. The infrared optical positioning device contains a positioning sensor and several positioning rigid bodies. The positioning sensor defines a spatial coordinate system. The ultrasound image defines an image coordinate system. In order to locate a point on the ultrasound image, The present invention installs the positioning rigid body 1 on the two-dimensional ultrasonic probe. Since the infrared optical positioning instrument can give the spatial coordinates of the positioning rigid body 1, that is, the transformation matrix between the infrared optical positioning instrument and the positioning rigid body 1 It is known that if the spatial transformation matrix between the positioning rigid body 1 and the ultrasound image is Knowing that, the spatial position of the ultrasound image area can be calculated using the following formula .

[0089]

[0090] 2. Ultrasonic probe calibration: Ultrasonic probe calibration is to obtain the spatial transformation matrix between the positioning rigid body 1 and the ultrasound image The specific calibration method is to use an ultrasonic probe equipped with a positioning rigid body 1 to scan the object in space, obtain the spatial coordinates and image coordinates of several points on the object, and finally calculate the coordinates by formula (1). Since a system of equations needs to be established, the number of points on the object must be greater than or equal to 3.

[0091] The spatial coordinates of a point on an object are obtained using a positioning tool provided by the infrared optical locator. The coordinates of the tip of the positioning tool are directly provided by the infrared optical locator. Therefore, simply touching a point on an object with the tip of the positioning tool will determine the spatial coordinates of that point.

[0092] The image coordinates of a point on an object are obtained by scanning the point with an ultrasound probe mounted on a positioning rigid body 1, acquiring an ultrasound image, and manually or automatically marking the object on the ultrasound image. Since the ultrasound image itself constitutes an image coordinate system, the image coordinates of the object can be calculated.

[0093] After completing the calibration of the ultrasound probe, the spatial transformation matrix between the positioning rigid body 1 and the ultrasound image can be obtained. .

[0094] Since there is no restriction on the display position of a point on an object on an ultrasound image, that is, any point on an ultrasound image satisfies formula (1), then formula (1) can be used to calculate the spatial position of any point on the ultrasound image, that is, the spatial position of the ultrasound image.

[0095] 3. Spatial positioning of bipolar coagulation forceps 3: To determine the spatial position of bipolar coagulation forceps 3, a positioning rigid body 2 is installed on the bipolar coagulation forceps 3. Since the infrared optical positioning instrument can give the spatial coordinates of the positioning rigid body 2, that is, the transformation matrix between the infrared optical positioning instrument and the positioning rigid body 2 For any point on the bipolar electrocoagulation forceps 3, if the coordinates of the point in the local coordinate system of the positioning rigid body 2 are known, , we can use formula (2) to calculate the spatial position of the three tips of the bipolar electrocoagulation forceps The position of the tip of the bipolar electrocoagulation forceps 3 relative to the steel body 2 is :

[0096]

[0097] Typically, when closed, the bipolar coagulation forceps 3 consists of a tip and a long axis. Therefore, in addition to locating the spatial position of the tip of the bipolar coagulation forceps 3, it is also necessary to know the direction of the long axis of the bipolar coagulation forceps 3. The direction of the long axis can be determined by the tip of the bipolar coagulation forceps 3 and another point on the long axis, that is, two points in space determine a straight line. Suppose the coordinates of the tip of the bipolar coagulation forceps 3 are (x1, y1, z1), and the coordinates of another point on the long axis are (x2, y2, z2). Then the equation of the straight line at any point (x, y, z) on the long axis of the bipolar coagulation forceps 3 is:

[0098]

[0099] 4. Intersection point between the long axis extension line of the bipolar coagulation forceps 3 and the ultrasound image: If the long axis extension line of the bipolar coagulation forceps 3 is not parallel to the ultrasound image plane, an intersection point will be generated. The calculation steps for this intersection point are as follows:

[0100] (1) Write the equation of the long axis line in “Spatial positioning of bipolar electrocoagulation forceps 3” into a parametric equation, that is, the intersection of the extension line of the forceps tip and the ultrasound image:

[0101]

[0102] Among them, v x =x2-x1,v y =y2-y1, v z =z2-z1, (x1, y1, z1) and (x2, y2, z2) are two points on the long axis straight line of the bipolar coagulation forceps 3.

[0103] (2) Assume that the upper left corner vertex of the ultrasound image is transformed by formula 1, and its spatial coordinate point is (n x , n y , n z). After the three vertices of the lower left corner, upper right corner and lower right corner of the ultrasound image are transformed by formula 1, they form three coordinate points in space. The vertices of the lower left corner and lower right corner constitute the bottom line, and the vertices of the upper right corner and lower right corner constitute the right line. Let the bottom line vector be (v bx , v by ,v bz ), the right side vector is (v ex , v ey , v ez ). Then the bottom line and the right side line of the ultrasound image in space constitute the normal vector of the image plane, so the normal vector is (v px , v py , v pz ). Then we have:

[0104]

[0105] Then, the point normal equation of the ultrasound image plane in space is:

[0106]

[0107] Then the formulas can be combined to get:

[0108]

[0109] By solving the formula corresponding to the intersection of the extension line of the forceps tip after t and the ultrasound image, the spatial coordinates of the intersection can be calculated.

[0110] 5. Calibration of the bipolar coagulation forceps 3: After the bipolar coagulation forceps 3 are installed on the positioning rigid body 2, the coordinates of a certain point on the bipolar coagulation forceps 3 in the local coordinate system of the positioning rigid body 2 need to be calculated through the calibration process. After the calibration is completed, the coordinates of the point on the bipolar coagulation forceps 3 in the spatial coordinate system can be calculated using Formula 2. Since the infrared optical locator can provide the coordinates of the tip of the positioning tool in a local coordinate system defined by a positioning rigid body in addition to providing the coordinates of the tip of the positioning tool in a spatial coordinate system, the infrared optical locator can also provide the coordinates of the tip of the positioning tool in a local coordinate system defined by a positioning rigid body. Therefore, through the setting function of the infrared optical locator, the coordinate system of the coordinate value output by the infrared optical locator is changed to the local coordinate system defined by the positioning rigid body 2. At this time, the positioning tool (such as Figure 3 ) touches the tip of the bipolar coagulation forceps 3 and records the coordinate value of the positioning tool tip. Then, the coordinate value is the coordinate of the tip of the bipolar coagulation forceps 3 in the local coordinate system of the positioning rigid body 2, which .... Finally, the coordinate system of the infrared optical locator output coordinate value is changed to the space coordinate system, and the transformation matrix between the positioning rigid body 2 and the infrared optical locator is The output of the infrared optical locator can be used to calculate the spatial coordinates of the tip of the bipolar electrocoagulation forceps 3 using Formula 2. The spatial coordinates of another point on the long axis of the bipolar electrocoagulation forceps 3 are also obtained using the same method.

[0111] The spatial coordinates of the tip of the bipolar coagulation forceps 3 and another point on the long axis are obtained by obtaining the spatial coordinates of the tip of the bipolar coagulation forceps 3 in real time as above, and the spatial coordinates of the extended line of the long axis of the bipolar coagulation forceps 3 and the ultrasound image plane.

[0112] Since the two-dimensional ultrasonic image and the spatial position and direction of the bipolar coagulation forceps 3 can be obtained by the above method in the spatial coordinate system, and the intersection of the long axis extension line of the bipolar coagulation forceps 3 and the ultrasonic image plane can be calculated, the spatial position relationship between the ultrasonic image and the bipolar coagulation forceps 3 can be visualized so that the operator can know the actual spatial position relationship between the ultrasonic image and the bipolar coagulation forceps 3. The operator can use the bipolar coagulation forceps 3 at any angle in space and complete the operation under the guidance of the ultrasonic image. Specifically, a three-dimensional visualization environment is established in the computer. The visualization environment is based on the spatial coordinate system defined by the infrared optical locator. The ultrasonic image and the bipolar coagulation forceps 3 are displayed in the visualization environment according to their spatial position and direction in the spatial coordinate system. Since the ultrasonic probe and the bipolar coagulation forceps 3 are respectively equipped with positioning rigid bodies, the infrared optical locator can provide the real-time coordinates of each positioning rigid body. Therefore, the spatial position and direction of the ultrasonic probe and the bipolar coagulation forceps 3 are also calculated in real time. The ultrasound image is collected into the computer and displayed as a two-dimensional image according to the actual size. The spatial position and direction of the two-dimensional image are calculated using Formula 1 to obtain the corresponding position in the visualization environment. The three-dimensional size of the bipolar coagulation forceps 3 is measured, and a three-dimensional model is established according to the actual size, and the corresponding position in the visualization environment is calculated according to Formula 2. The spatial coordinates of the intersection of the extension line of the bipolar coagulation forceps 3 and the ultrasound image plane are calculated using the method in "Intersection of the long axis extension line of the bipolar coagulation forceps 3 and the ultrasound image" , use formula 8 to calculate the location of the intersection point on the ultrasound image .

[0113]

[0114] in, and They are respectively and On the ultrasound two-dimensional image, draw a point The colored graphic with centered indicates the spatial position that the bipolar electrocoagulation forceps 3 finally reaches when moving in the long axis direction.

[0115] The present invention utilizes commonly used ultrasound in hospitals to spatially locate the ultrasound image and bipolar electrocoagulation forceps 3 during brain tumor surgery, displaying the spatial positional relationship between the two in real time to guide the doctor in completing the surgical operation. Specific implementation is as follows:

[0116] Configure the environment;

[0117] Hardware requirements: ordinary computer, image acquisition card, ultrasound scanner and infrared optical locator;

[0118] Software requirements: Windows, VTK or other visualization toolkits, VS2008 or other development tools.

[0119] Data preparation;

[0120] Use an image acquisition card to acquire the ultrasound images output by the ultrasound scanner in real time and transfer them to the computer. Use VTK or other 3D modeling software to build a 3D model of the positioning sensor, ultrasound probe, and bipolar electrocoagulation forceps 3.

[0121] Ultrasound probe calibration;

[0122] A positioning rigid body (positioning rigid body 1) of an infrared optical positioning instrument is installed on the ultrasound probe. The installation position should not hinder the use of the probe.

[0123] Use a 3D printer or other methods to make a calibration model with 6 intersections, such as Figure 2 The six intersection points are required to be coplanar. The spatial coordinates of the six intersection points are obtained using the positioning tool provided by the infrared optical positioning instrument, such as Figure 3 The image coordinates of the six intersection points are obtained by scanning the six points with an ultrasound probe mounted on the positioning rigid body 1, and manually adjusting the six points so that they can all be clearly displayed on the ultrasound image. Figure 4 Obtain an ultrasound image and manually or automatically mark the object on the ultrasound image. Calculate the image coordinates of each point in the image coordinate system. Finally, use formula (1) to deduce .

[0124] Bipolar coagulation forceps 3 calibration;

[0125] Here, we take the bipolar electrocoagulation forceps 3 as an example, and install the positioning rigid body 2 on the bipolar forceps. Figure 5 As shown. Set the coordinate system of the coordinate value output by the infrared optical locator to the local coordinate system defined by the positioning rigid body 2. At this time, use the tip of the positioning tool to touch the tip of the bipolar closure and record the coordinate value of the tip of the positioning tool. This coordinate value is the coordinate of the tip of the bipolar electrocoagulation forceps 3 in the local coordinate system of the positioning rigid body 2. Then, change the coordinate system of the coordinate value output by the infrared optical locator to the spatial coordinate system, and the transformation matrix between the positioning rigid body 2 and the infrared optical locator. The output of the infrared optical locator can be used to calculate the spatial coordinates of the tip of the bipolar electrocoagulation forceps 3 using Formula 2. Another point on the bipolar long axis is selected, and the spatial coordinates of this point are obtained using the same method.

[0126] 3D navigation;

[0127] The program written by the present invention reads the bipolar model file (forceps.vtk) and uses a certain color rendering to display it in a three-dimensional space, specifically as follows: Figure 6 shown.

[0128] The ultrasound image captured by the acquisition card is displayed in real time in three-dimensional space using the VTK function. The intersection of the bipolar long axis extension line and the two-dimensional ultrasound image plane is calculated using the method of the present invention and displayed on the ultrasound image as a square centered on the intersection.

[0129] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It should be understood that many modifications may be made to the illustrative embodiments, and that other arrangements may be devised, without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in ways other than those described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in conjunction with other described embodiments.

Claims

1. An ultrasound positioning system for brain tumor surgery, characterized in that: It includes a two-dimensional ultrasound scanner (1), an infrared optical positioning device (2), multiple positioning rigid bodies, bipolar electrocoagulation forceps (3), a processor and a display; The handle of the two-dimensional ultrasonic scanner (1) and the handle of the bipolar electrocoagulation forceps (3) are respectively provided with a positioning rigid body 1 and a positioning rigid body 2; A two-dimensional ultrasonic scanner (1) is used for collecting two-dimensional ultrasonic images in real time during brain surgery; the two-dimensional ultrasonic images include two-dimensional images of brain tumors; and the two-dimensional ultrasonic images are sent to a processor; The infrared optical positioning device (2) is used to spatially position the positioning rigid body 1 and the positioning rigid body 2; and transmit the spatial positioning information to the processor; The processor obtains the spatial position of the tip and handle of the bipolar electrocoagulation forceps (3) according to the spatial position of the positioning rigid body 2, and also obtains the spatial position of the tip and handle of the bipolar electrocoagulation forceps (3) according to the spatial position of the positioning rigid body 1 and the spatial transformation matrix of the ultrasound image. , obtaining the spatial region coordinates of the two-dimensional ultrasound image; The processor simultaneously obtains the spatial position of the extension line of the tip of the bipolar coagulation forceps (3) based on the spatial position and structure of the tip and handle of the bipolar coagulation forceps (3); and also calculates the coordinates of the intersection of the extension line of the tip of the bipolar coagulation forceps (3) and the spatial area of ​​the two-dimensional ultrasound image using the spatial area coordinates of the two-dimensional ultrasound image and the spatial position of the extension line of the tip of the bipolar coagulation forceps (3); The processor also uses three-dimensional visualization technology to establish a bipolar coagulation forceps model, and creates a three-dimensional scene image of the spatial area of ​​the bipolar coagulation forceps and the two-dimensional ultrasound image based on the spatial coordinates of the two-dimensional ultrasound image and the spatial coordinates of the tip of the bipolar coagulation forceps and its extension line; and sends the three-dimensional scene image to the display in real time; The display is used to display the three-dimensional scene image.

2. The ultrasound positioning system for brain tumor surgery according to claim 1, characterized in that: The method for obtaining the spatial region coordinates of a two-dimensional ultrasound image is: An object in space is scanned using a two-dimensional ultrasonic scanner (1) equipped with a positioning rigid body 1 to obtain spatial coordinates and image coordinates of multiple points on the object. The spatial coordinates and image coordinates of more than three points on the object are respectively substituted into Formula 1 to establish a set of equations to obtain a spatial transformation matrix between the positioning rigid body 1 and the ultrasonic image. ; Formula 1 in, represents the image coordinates of a point on the ultrasound image, represents the spatial transformation matrix between the infrared optical positioning device (2) and the positioning rigid body 1; Represents the spatial coordinates of a point; The positioning rigid body 1 fixed on the handle of the two-dimensional ultrasonic scanner (1) is positioned by an infrared optical positioning device (2), and the spatial region coordinates of the two-dimensional ultrasonic image are obtained by combining the positioning rigid body 1 with formula 1.

3. The ultrasound positioning system for brain tumor surgery according to claim 1 or 2, characterized in that: The method for obtaining the position of the tip of the bipolar electrocoagulation forceps (3) and the spatial position of its handle is as follows: Positioning the positioning rigid body 2 fixed on the handle of the bipolar electrocoagulation forceps (3) by using an infrared optical positioning device (2), and obtaining the spatial position of the tip of the bipolar electrocoagulation forceps (3) relative to the rigid body 2 by using formula 2; Formula 2 in, Represents the transformation matrix between the infrared optical locator and the positioning rigid body 2, Indicates the spatial position of the positioning rigid body 2, Indicates the spatial position of the tip of the bipolar electrocoagulation forceps (3) relative to the steel body 2; The straight line on which the handle of the bipolar coagulation forceps (3) is located is obtained by formula 3. The straight line equation of the coordinates (x, y, z) of any point on the long axis of the bipolar coagulation forceps (3) is: Formula 3.

4. The ultrasound positioning system for brain tumor surgery according to claim 3, characterized in that: The method for obtaining the spatial position coordinates of the extension line of the tip of the bipolar coagulation forceps (3) by using the tip position of the bipolar coagulation forceps (3) and the spatial position of the handle thereof is as follows: Formula 4 Among them, v x =x2-x1,v y =y2-y1,v z =z2-z1, (x1, y1, z1) and (x2, y2, z2) represent the coordinates of two points on the long axis straight line of the bipolar coagulation forceps (3), and t represents the slope of the extension line of the coagulation forceps.

5. The ultrasound positioning system for brain tumor surgery according to claim 4, characterized in that: The method for obtaining the intersection point when the extension line of the electrocoagulation forceps intersects the spatial area of ​​the two-dimensional ultrasound image is as follows: Formula 1 is used to calculate the spatial coordinates of the upper left vertex, lower left vertex, upper right vertex, and lower right vertex of the ultrasound image. The line connecting the lower left vertex and the lower right vertex is used as the bottom line, and the line connecting the upper right vertex and the lower right vertex is used as the right line. The bottom line vector is (v bx , v by , v bz ), the right side vector is (v ex , v ey , v ez The bottom line and the right side line of the ultrasound image in space constitute the normal vector of the image plane (v px , v py , v pz ): Formula 5 Then, the point normal equation of the ultrasound image plane in space is: Formula 6 Among them, (n x , n y , n z ) represents the spatial coordinate of the upper left corner vertex of the ultrasound image, then Formula 4 and Formula 6 are combined to obtain: Formula 7 After solving for t, substitute t into formula 4 to calculate the spatial coordinates of the intersection point where the extension line of the coagulation forceps intersects the spatial area of ​​the two-dimensional ultrasound image.

6. The ultrasound positioning system for brain tumor surgery according to claim 1, characterized in that: The processor converts the coordinates of the intersection of the extension line of the tip of the bipolar electrocoagulation forceps (3) and the spatial area of ​​the two-dimensional ultrasound image into the coordinates of the two-dimensional ultrasound image, and marks the intersection in the two-dimensional ultrasound image.

7. The ultrasound positioning system for brain tumor surgery according to claim 5, characterized in that: The formula for converting the coordinates of the intersection of the extension line of the bipolar coagulation forceps tip and the two-dimensional ultrasound image space area into the two-dimensional ultrasound image coordinates is: Formula 8 in, Represents the coordinates of the intersection of the extension line of the bipolar coagulation forceps and the spatial area of ​​the two-dimensional ultrasound image on the two-dimensional ultrasound image.

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