Method and navigation system for navigating two intracranial operating instruments

Abstract

The application discloses a method and a navigation system for navigation of two intracranial operation instruments, the method comprising: acquiring an anatomical image; marking a surgical path in the anatomical image; registering the anatomical image in an optical coordinate system based on a pose of a first optical tracker in the optical coordinate system and a pose in an image coordinate system of the anatomical image; acquiring a pose of a second optical tracker in the optical coordinate system by using an optical navigation device; acquiring a pose of a third optical tracker in the optical coordinate system by using the optical navigation device, obtaining a pose of a first electromagnetic sensor in the optical coordinate system based on the pose of the third optical tracker in the optical coordinate system, a pose relationship between a magnetic field generator and the third optical tracker, and a pose of the first electromagnetic sensor relative to the magnetic field generator; calibrating the pose of the first electromagnetic sensor; and obtaining a pose of a first instrument in the optical coordinate system and a calibrated pose of a second instrument in the optical coordinate system.

Description

Technical Field

[0001] This invention relates to the field of surgical navigation technology, and more particularly to a method and system for navigating two intracranial manipulation instruments in neurosurgery. Background Technology

[0002] Currently, there are two typical navigation systems for surgical procedures: optical navigation systems based on optical positioning and tracking principles, and electromagnetic navigation systems based on electromagnetic positioning and tracking principles. Both systems have their own advantages and disadvantages. Specifically, optical navigation systems offer the advantage of accurate positioning and tracking of medical instruments. However, their disadvantage is that if the optical tracker attached to the medical instrument and the imaging device in the optical navigation system are blocked, positioning and tracking of the instrument cannot be achieved. Electromagnetic navigation systems, on the other hand, rely on the change in current induced in the magnetic field generated by an electromagnetic coil to position and track the instrument. Therefore, their advantage is that they are unaffected by optical obstructions and can be used in small operating spaces and enclosed lumens. However, their disadvantage is that positioning and tracking are less accurate than optical navigation systems, especially when the magnetic field is distorted by surrounding equipment, further worsening their accuracy.

[0003] Navigation systems are used in neurosurgery (e.g., intracranial surgery) to visualize instruments during the procedure. Because neurosurgery requires high precision in the operation of instruments, optical navigation systems are typically used to locate and track them. An advantage of using optical navigation systems in neurosurgery is that the instruments are usually rigid and their outer (or proximal) ends are located outside the body. Thus, the optical tracker can be mounted on the outer end of the instrument to avoid being obstructed by human tissue. Furthermore, in some surgical procedures (e.g., tumor biopsy), if only one instrument is needed, the probability of the optical tracker being obstructed by external objects can be significantly reduced based on the surgeon's skillful operation.

[0004] In many types of neurosurgical procedures, the use of two instruments is unavoidable (e.g., in glioma resection, two instruments are often used simultaneously). This involves inserting two instruments into the skull incision, which typically serve different functions during the procedure. For example, a neuroendoscope and a scalpel (e.g., an phacoemulsification aspiration scalpel) may be inserted simultaneously into the skull incision; the neuroendoscope provides intracranial visualization, while the scalpel removes the tumor. In existing techniques, the following problems exist when both instruments are positioned and tracked using optical navigation systems:

[0005] To achieve positioning and tracking, two optical trackers are attached to the outer ends (i.e., the proximal handheld ends) of the two instruments respectively. During the operation, the optical trackers on the two instruments occupy a large space and are prone to mutual interference or mutual obstruction of optical markers (reflective components used to reflect light to the imaging device for positioning and tracking). Mutual interference will affect the permissible range of motion of the instruments, while obstruction of light markers will cause interruption of positioning and tracking of the instruments. Summary of the Invention

[0006] To address the aforementioned technical problems in the prior art, embodiments of the present invention provide a method and navigation system for navigating two intracranial manipulation instruments.

[0007] To solve the above-mentioned technical problems, the technical solution adopted in the embodiments of the present invention is as follows:

[0008] A method for navigating two intracranial manipulation instruments, the two instruments including a first instrument and a second instrument, characterized in that a first optical tracker is attached to a surgical site, a second optical tracker and a first electromagnetic sensor are respectively attached to the first and second instruments in a defined pose relationship, and a third optical tracker has a defined pose relationship with a magnetic field generator, the method comprising:

[0009] Obtain anatomical images describing the anatomical structures of the surgical site;

[0010] Mark the target area, cranial entrance, and surgical path in the anatomical images;

[0011] The pose of the first optical tracker in the optical coordinate system is obtained using an optical navigation device, and the anatomical image is registered in the optical coordinate system based on the pose of the first optical tracker in the optical coordinate system and its pose in the image coordinate system of the anatomical image.

[0012] The poses of the second and third optical trackers in the optical coordinate system are obtained using an optical navigation device, and the pose of the first electromagnetic sensor relative to the magnetic field generator is obtained using an electromagnetic navigation device. Based on the pose of the third optical tracker in the optical coordinate system, the pose relationship between the magnetic field generator and the third optical tracker, and the pose of the first electromagnetic sensor relative to the magnetic field generator, the pose of the first electromagnetic sensor in the optical coordinate system is obtained.

[0013] The pose of the first electromagnetic sensor is calibrated;

[0014] Based on the pose relationship between the second optical tracker and the first instrument, and the pose relationship between the first electromagnetic sensor and the second instrument, the pose of the first instrument in the optical coordinate system and the calibrated pose of the second instrument in the optical coordinate system are obtained, and the first and second instruments are visualized in the anatomical image.

[0015] Preferably, the first instrument and the second instrument can be rigidly and separably attached, and in the attached state, the first instrument and the second instrument have a defined positional relationship.

[0016] The calibration of the pose of the first electromagnetic sensor includes:

[0017] The pose of the first electromagnetic sensor relative to the second optical tracker is obtained based on the pose relationship between the first and second instruments in the attached state.

[0018] The pose of the first electromagnetic sensor in the optical coordinate system, obtained from the pose of the first electromagnetic sensor relative to the second optical tracker in the attached state and the pose of the second optical tracker in the optical coordinate system obtained by the optical navigation device, is used as the reference pose.

[0019] The pose of the first electromagnetic sensor in the optical coordinate system obtained by the optical navigation device in the attached state, the pose relationship between the magnetic field generator and the third optical tracker, and the pose of the first electromagnetic sensor relative to the magnetic field generator obtained by the electromagnetic navigation device are used as the pose to be calibrated.

[0020] A calibration matrix is ​​obtained based on the pose to be calibrated and the reference pose of the first electromagnetic sensor, and the pose of the first electromagnetic sensor in the optical coordinate system is calibrated using the calibration matrix.

[0021] Preferably, the second electromagnetic sensor is placed at or near the surgical site;

[0022] The calibration of the pose of the first electromagnetic sensor includes:

[0023] The pose of the second electromagnetic sensor in the optical coordinate system, obtained based on the pose of the first or second optical tracker in the optical coordinate system, is used as the reference pose of the second electromagnetic sensor.

[0024] The pose of the second electromagnetic sensor in the optical coordinate system, obtained from the pose of the magnetic field generator in the optical coordinate system and the pose of the second electromagnetic sensor relative to the magnetic field generator obtained by the electromagnetic navigation device, is taken as the pose to be calibrated of the second electromagnetic sensor.

[0025] The pose of the first electromagnetic sensor in the optical coordinate system, obtained from the pose of the magnetic field generator in the optical coordinate system and the pose of the first electromagnetic sensor relative to the magnetic field generator obtained by the electromagnetic navigation device, is taken as the pose to be calibrated of the first electromagnetic sensor.

[0026] A calibration matrix is ​​obtained based on the pose to be calibrated and the reference pose of the second electromagnetic sensor, and the pose to be calibrated of the first electromagnetic sensor is calibrated using the calibration matrix.

[0027] Preferably, the second electromagnetic sensor is attached to the distal region of the first device in a manner that forms a defined pose relationship with the second optical tracker, and the first electromagnetic sensor is attached to the distal region of the second device.

[0028] The reference pose of the second electromagnetic sensor in the optical coordinate system, obtained based on the pose of the second optical tracker in the optical coordinate system, includes:

[0029] The reference pose of the second electromagnetic sensor in the optical coordinate system is obtained based on the pose of the second optical tracker in the optical coordinate system obtained by the optical navigation device and the pose relationship between the second electromagnetic sensor and the second optical tracker.

[0030] Preferably, the second electromagnetic sensor and the first optical tracker have a defined pose relationship;

[0031] The reference pose of the second electromagnetic sensor in the optical coordinate system, obtained based on the pose of the first optical tracker in the optical coordinate system, includes:

[0032] The reference pose of the second electromagnetic sensor in the optical coordinate system is obtained based on the pose of the first optical tracker in the optical coordinate system acquired by the optical navigation device and the pose relationship between the second electromagnetic sensor and the first optical tracker.

[0033] The present invention also discloses a navigation system for surgical navigation of two intracranial manipulation instruments, the two manipulation instruments including a first instrument and a second instrument, and the navigation system including an image acquisition device, a navigation instrument and a computer device;

[0034] The navigation device includes an optical navigation device, a first, second, and third optical tracker, an electromagnetic navigation device, and a first electromagnetic sensor;

[0035] Computer equipment includes processing and control equipment and display equipment;

[0036] The first optical tracker is attached to the surgical site, the second optical tracker and the first electromagnetic sensor are attached to the first and second instruments respectively in a defined pose relationship, and the third optical tracker is attached to the periphery of the surgical site and has a defined pose relationship with the magnetic field generator.

[0037] Image acquisition devices are used to acquire raw images that describe the anatomical structures of the surgical site;

[0038] The optical navigation device is used to acquire the pose of the first, second, and third optical trackers in the optical coordinate system;

[0039] The electromagnetic navigation device is used to obtain the pose of the first electromagnetic sensor relative to the magnetic field generator;

[0040] The processing and control equipment is used for:

[0041] The image to be processed is converted into an anatomical image;

[0042] The anatomical image is registered in the optical coordinate system based on the pose of the first optical tracker in the optical coordinate system and its pose in the image coordinate system of the anatomical image.

[0043] The pose of the first instrument in the optical coordinate system is calculated based on the pose of the second optical tracker in the optical coordinate system and its pose relationship with the first instrument; and the pose of the second instrument in the optical coordinate system is calculated based on the pose of the third optical tracker in the optical coordinate system, the pose relationship between the magnetic field generator and the third optical tracker, the pose of the first electromagnetic sensor relative to the magnetic field generator and its pose relationship with the second instrument.

[0044] The pose of the first electromagnetic sensor is calibrated;

[0045] The display device is used to visualize the first and second instruments in anatomical images.

[0046] Preferably, the first instrument has a first positioning structure, the second instrument has a second positioning structure, the first instrument and the second instrument can be detachably attached through the first positioning structure and the second positioning structure, and in the attached state, the first instrument and the second instrument have a definite positional relationship.

[0047] The processing control device is used for:

[0048] The pose of the first electromagnetic sensor relative to the second optical tracker is calculated based on the pose relationship between the first and second instruments in the attached state. The pose of the first electromagnetic sensor in the optical coordinate system is calculated based on the pose of the first electromagnetic sensor relative to the second optical tracker in the attached state and the pose of the second optical tracker in the optical coordinate system, and is used as the reference pose. The pose of the first electromagnetic sensor in the optical coordinate system is calculated based on the pose of the third optical tracker in the optical coordinate system in the attached state, the pose relationship between the magnetic field generator and the third optical tracker, and the pose of the first electromagnetic sensor relative to the magnetic field generator, and is used as the pose to be calibrated. A calibration matrix is ​​calculated based on the pose to be calibrated and the reference pose of the first electromagnetic sensor, and the pose of the first electromagnetic sensor in the optical coordinate system is calibrated using the calibration matrix.

[0049] Preferably,

[0050] The navigation device also includes a second electromagnetic sensor, which is disposed at or near the surgical site.

[0051] The processing control device is used for:

[0052] The pose of the second electromagnetic sensor in the optical coordinate system is calculated based on the pose of the first or second optical tracker in the optical coordinate system obtained by the optical navigation device and used as the reference pose. The pose of the second electromagnetic sensor in the optical coordinate system is calculated based on the pose of the magnetic field generator in the optical coordinate system and the pose of the second electromagnetic sensor relative to the magnetic field generator obtained by the electromagnetic navigation device and used as the pose to be calibrated. The pose of the first electromagnetic sensor in the optical coordinate system is calculated based on the pose of the magnetic field generator in the optical coordinate system and the pose of the first electromagnetic sensor relative to the magnetic field generator obtained by the electromagnetic navigation device and used as the pose to be calibrated. A calibration matrix is ​​calculated based on the pose to be calibrated of the second electromagnetic sensor and the reference pose, and the pose to be calibrated of the first electromagnetic sensor is calibrated using the calibration matrix.

[0053] Preferably,

[0054] The first electromagnetic sensor is arranged in the distal region of the second instrument, and the second electromagnetic sensor is arranged in the distal region of the first instrument.

[0055] Preferably, the first electromagnetic sensor is arranged in the proximal region of the second device and the second electromagnetic sensor is arranged on the first optical tracker.

[0056] Compared with the prior art, the beneficial effects of the method and navigation system for navigating two intracranial manipulation instruments provided by the embodiments of the present invention are as follows:

[0057] 1. By simultaneously operating the electromagnetic navigation device and the optical navigation device, navigation of the first and second instruments is performed simultaneously. Furthermore, the navigation of the second instrument is achieved by the optical navigation device and the electromagnetic navigation device cooperating to obtain the pose of the first electromagnetic sensor in the optical coordinate system. This avoids the need to configure an optical tracker on the second instrument for navigation. As a result, the probability of the second optical tracker on the first instrument being blocked by the second instrument and the probability of mutual mechanical interference are significantly reduced because it is not necessary to configure an optical tracker on the second instrument. This reduces the probability of navigation of the operating instruments being interrupted due to blocking and significantly increases the range of motion of the two operating instruments.

[0058] 2. The second instrument, which has a smaller potential for damage to intracranial tissues due to positional deviation, is navigated by a combination of optical and electromagnetic navigation equipment, while the first instrument, which has a larger potential for damage to intracranial tissues due to positional deviation, is navigated only by optical navigation equipment. This reduces the impact of navigation deviations in electromagnetic navigation on surgical risks and outcomes.

[0059] 3. By calibrating the positional deviation of the second instrument caused by electromagnetic navigation, the positional deviation of the second instrument can be corrected to a certain extent, thereby improving the navigation accuracy of the second instrument to a certain degree.

[0060] 4. Other advantages of the present invention are described directly or implicitly in the specific embodiments of the specification. Attached Figure Description

[0061] Figure 1 This is a schematic diagram showing the configuration relationship of the relevant components of the navigation system provided by the present invention.

[0062] Figure 2 A flowchart of the navigation method provided by the present invention.

[0063] Figure 3 This is a flowchart illustrating the specific implementation steps of step S10 in the navigation method provided by the present invention.

[0064] Figure 4 This is a flowchart illustrating the specific implementation steps of step S20 in the navigation method provided by the present invention.

[0065] Figure 5 The anatomical image provided by the present invention marks the first approach path.

[0066] Figure 6 Anatomical images showing the second approach path provided by the present invention.

[0067] Figure 7 This is a schematic diagram illustrating the process of obtaining the pose of related instruments and equipment using a transformation matrix method, as provided by the present invention.

[0068] Figure 8 This is a flowchart of a first method for calibrating the pose of a first electromagnetic sensor provided by the present invention.

[0069] Figure 9 This is a schematic diagram of the calibration process of the first method for calibrating the pose of the first electromagnetic sensor, represented by a transformation matrix.

[0070] Figure 10 This is a flowchart of a second method for calibrating the pose of a first electromagnetic sensor provided by the present invention.

[0071] Figure 11This is a schematic diagram of the calibration process of the second method for calibrating the pose of the first electromagnetic sensor, represented by a transformation matrix.

[0072] Figure label:

[0073] 10-Optical navigation device; 101-Camera; 11-First optical tracker; 12-Second optical tracker; 13-Third optical tracker; 20-Electromagnetic navigation device; 21-First electromagnetic sensor; 22-Second electromagnetic sensor; 221-Miniature gimbal; 23-Magnetic field generator; 31-First instrument; 32-Second instrument; 40-Computer equipment; 41-Display device; 42-Processing and control equipment; 50-Operating table. Detailed Implementation

[0074] To keep the following description of the embodiments of the present invention clear and concise, detailed descriptions of known functions and known components are omitted.

[0075] Embodiments of this invention disclose a navigation system for assisting physicians in performing neurosurgical procedures to treat lesions in intracranial brain tissue. This navigation system can specifically be referred to as a neurosurgical navigation system. The navigation system and method described below are designed to simultaneously navigate two intracranial manipulation instruments (navigating instruments can also be referred to as locating and tracking instruments). Therefore, the navigation system and method provided by this invention are suitable for neurosurgical procedures requiring two intracranial manipulation instruments to be simultaneously located within the cranium.

[0076] The navigation system and navigation method provided by this invention target two intracranial manipulation instruments that play different roles in surgery. Specifically, one of the two intracranial manipulation instruments is used to remove lesions in brain tissue (such as brain tumors) through procedures such as resection and dissection, while the other instrument is not used to remove lesions but to perform auxiliary tasks such as guidance, cleaning, and dilation. Furthermore, one of the two instruments (let's call it the first instrument 31) belongs to the category of instruments that, if not operated accurately, can easily cause serious damage to brain tissue at its distal end, while the other instrument (let's call it the second instrument 32) belongs to the category of instruments that, even if operated with low precision, will not cause serious damage to brain tissue. For example, the first instrument 31 is an ultrasonic emulsification aspiration knife (such as a Cusa knife) used to remove brain tumors, and the second instrument 32 is a neuroendoscopy used to guide and expand or enhance the field of vision.

[0077] like Figure 1 As shown, the navigation system provided by the present invention includes: an image acquisition device, a navigation instrument, and a computer device 40.

[0078] Before surgery, images describing the anatomical structures of the patient's head are acquired using image acquisition equipment, such as computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), or digital subtraction angiography (DSA). Images acquired by a single device can be directly used as anatomical images for subsequent surgical path planning and navigation, or multimodal fusion technology can be used to fuse images acquired from at least two of the aforementioned devices to create the anatomical images. Figure 5 and Figure 6 As shown, the anatomical images are preferably composite images, which include, but are not limited to, three-dimensional images, coronal images, sagittal images, and transverse images. The images provided by the aforementioned device can be used to construct a three-dimensional model of the head to obtain a three-dimensional image describing the head.

[0079] The navigation device includes: an optical navigation device 10 equipped with a camera 101, a first optical tracker 11, a second optical tracker 12, a third optical tracker 13, an electromagnetic navigation device 20 equipped with a magnetic field generator 23, and a first electromagnetic sensor 21. In some preferred embodiments, the navigation device further includes a second electromagnetic sensor 22.

[0080] Each of the first optical tracker 11, the second optical tracker 12, and the third optical tracker 13 has at least three optical markers that are not on the same straight line. These optical markers can be identified by the camera 101 of the optical navigation device 10. In a preferred embodiment of the present invention, each optical tracker has four optical markers, and these optical markers are typically reflective spheres that can be identified by the camera 101 by reflecting light (not self-illuminating). Thus, the optical navigation device 10 can obtain an image describing the optical tracker by taking a picture of the optical tracker with the optical markers using the camera 101. By analyzing the image, the pose of the optical tracker relative to the camera 101 (the pose specifically refers to position and orientation) can be obtained, thereby enabling navigation of the device attached to the optical tracker. That is, based on the optical positioning and tracking principle (i.e., the optical navigation principle), the optical navigation device 10 can achieve navigation of the device by obtaining the pose of the optical tracker. The analysis and processing module and application program used to analyze images to obtain the pose of the optical tracker can be integrated into the optical navigation device 10 or into the computer device 40 mentioned above.

[0081] The magnetic field generator 23 in the electromagnetic navigation device 20 generates an electromagnetic field. The first electromagnetic sensor 21 and the second electromagnetic sensor 22 are placed in the electromagnetic field generated by the magnetic field generator 23. The core components of the first electromagnetic sensor 21 and the second electromagnetic sensor 22 are electromagnetic coils. Based on the electromagnetic positioning and tracking principle (i.e., the electromagnetic navigation principle), the electromagnetic coils in the electromagnetic sensors are induced to generate current in the electromagnetic field. By using the current as a parameter and analyzing the current, the position and orientation of the electromagnetic sensors relative to the magnetic field generator 23 can be obtained. The analysis and processing module and application program used to analyze the current to obtain the position and orientation of the electromagnetic sensors can be integrated into the electromagnetic navigation device 20 or into the aforementioned computer device 40.

[0082] Before acquiring images describing the anatomical structure of the patient's head using image acquisition devices such as CT or MRI equipment, a first optical tracker 11 is fixedly attached to the patient's head. For example, the lower end of the first optical tracker 11 is screwed into the skull of the patient's head to fix the first optical tracker 11 to the patient's head. Thus, after the image of the anatomical structure of the patient's head is acquired using the image acquisition device, the first optical tracker 11 is also displayed in the image. In order to align the image of the first optical tracker 11 subsequently acquired by the camera 101 with the image of the anatomical structure acquired by the image acquisition device, and thus for subsequent registration of the anatomical images in the optical coordinate system, the first optical tracker 11 also needs to be equipped with markers that are easily recognized by the image acquisition device and can enhance the display in the acquired image describing the anatomical structure. Preferably, the markers are placed on the surface or center of each reflective sphere to reduce the difficulty of aligning the first optical tracker 11.

[0083] The second optical tracker 12 is fixedly and detachably attached to the proximal end (or outer end or handheld end) of the first instrument 31. Based on the structure and dimensions of the second optical tracker 12 and the first instrument 31, there is a defined and known pose relationship between the second optical tracker 12 and the first instrument 31. The third optical tracker 13 is fixedly and detachably attached to the fixed device, preferably at the apex of the proximal side of the operating table 50. Similarly, based on the structure and dimensions of the third optical tracker 13 and the operating table 50, there is a defined and known pose relationship between the third optical tracker 13 and the operating table 50.

[0084] An optical navigation device 10 is positioned on one side of the operating table 50, and a camera 101 is mounted on the optical navigation device 10. Preferably, the optical navigation device 10 also includes a processing module for processing and analyzing images captured by the camera 101 to ultimately obtain the pose of the optical trackers, and a transmission module for communicating with the computer device 40. The specific placement of the optical navigation device 10 must satisfy the following condition: the patient's head and surrounding area, the first optical tracker 11, the second optical tracker 12, and the third optical tracker are all within the field of view of the camera 101, so that the poses of the first optical tracker 11, the second optical tracker 12, and the third optical tracker can be acquired simultaneously and in real time.

[0085] The magnetic field generator 23 is positioned proximal to the operating table 50. Based on the structure and dimensions of the magnetic field generator 23 and the operating table 50, there is a definite and known pose relationship between the magnetic field generator 23 and the operating table 50. Furthermore, since there is a definite and known pose relationship between the third optical tracker 13 and the operating table 50, there is also a definite and known pose relationship between the magnetic field generator 23 and the third optical tracker 13. Specifically, a rectangular notch is provided proximal to the operating table 50, and the magnetic field generator 23 is installed in the notch. Thus, the magnetic field generator 23 is located directly below the head and its surrounding area. Because the magnetic field generator 23 is installed in the notch, the magnetic field (magnetic field lines) generated by the magnetic field generator 23 is less affected by the thickness of the operating table 50. Preferably, the operating table 50 is configured as a rectangular plate structure with uniform texture and thickness to reduce local magnetic field distortion.

[0086] The first electromagnetic sensor 21 is fixedly and detachably attached to the second instrument 32. Specifically, for example, the first electromagnetic sensor 21 is attached to the inner side of the tube wall in the distal region of the second instrument 32, or, for example, to the outer side of the tube wall in the proximal region of the second instrument 32. Based on the structure and size of the first electromagnetic sensor 21 and the second instrument 32, there is a definite and known pose relationship between the first electromagnetic sensor 21 and the second instrument 32. In the configuration with the second electromagnetic sensor 22, if the first electromagnetic sensor 21 is attached to the distal region of the second instrument 32, then the second electromagnetic sensor 22 is fixedly and detachably attached to the first instrument 31, thereby achieving a result where the second electromagnetic sensor 22 and the first electromagnetic sensor 21 are as close as possible during the surgical procedure; if the first electromagnetic sensor 21 is attached to the proximal region of the second instrument 32, then the second electromagnetic sensor 22 is attached to the first optical tracker 11 to achieve the desired proximity to the first electromagnetic sensor 21. Based on the structure and dimensions of the second electromagnetic sensor 22 and the attached device, there is a definite and known pose relationship between the second electromagnetic sensor 22 and the attached device. Furthermore, the second electromagnetic sensor 22 can be placed within a miniature gimbal 221, thus allowing the attitude of the second electromagnetic sensor 22 to be adjusted in real-time and in a known manner by the miniature gimbal.

[0087] A desktop or laptop computer with a display device 41 (e.g., a monitor) and a processing control device 42 (e.g., a host) from the prior art can be used as the computer device 40. The computer device 40 integrates an application based on a navigation system and navigation method, which enables the computer device 40 to have display, storage and control functions.

[0088] The processing control device 42 is used to store the following data: anatomical images from the image acquisition device describing the anatomical structure of the patient's head; the shape and size data of related instruments or devices, such as the operating table 50, magnetic field generator 23, camera 101, first optical tracker 11, second optical tracker 12, third optical tracker 13, first electromagnetic sensor 21, second electromagnetic sensor 22, etc.; the determined pose relationship data of related instruments or devices, such as the pose relationship data between the second optical tracker 12 and the first instrument 31, the third optical tracker 13 and the magnetic field generator 23, the first electromagnetic sensor 21 and the second instrument 32, the second electromagnetic sensor 22 and the first instrument 31 or the first optical tracker 11, etc.; and the data of the preset coordinate systems representing the poses of the related instruments or devices, as well as the data of the optical coordinate system.

[0089] The processing and control device 42 is used to perform the following data reception, data processing, and calculation:

[0090] The processing and control device 42 is used to receive, in real time, the positional relationship data of the relevant instruments or equipment acquired by the optical navigation device 10 and the electromagnetic navigation device 20.

[0091] The processing control device 42 is used to calculate the pose of the relevant instruments or devices in the optical coordinate system based on the stored pose relationship data between instruments or devices and the pose data of the relevant instruments or devices acquired by the optical navigation device 10 and the electromagnetic navigation device 20. For example, the pose of the first instrument 31 in the optical coordinate system is obtained by performing calculations on the stored pose relationship data of the first instrument 31 relative to the second optical tracker 12 and the pose data of the second optical tracker 12 in the optical coordinate system acquired by the optical navigation device 10. As another example, the pose data of the third optical tracker 13 in the optical coordinate system acquired by the optical navigation device 10, the stored pose relationship data of the magnetic field generator 23 relative to the third optical tracker 13, and the pose data of the first electromagnetic sensor 21 relative to the magnetic field generator 23 acquired by the electromagnetic navigation device 20 are used to perform calculations to obtain the pose of the first electromagnetic sensor 21 in the optical coordinate system.

[0092] The processing control device 42 is also used to calculate the pose deviation data between the device or apparatus obtained entirely based on the optical positioning and tracking principle and the device or apparatus obtained based on the electromagnetic positioning and tracking principle, and thereby use it as calibration data to correct the pose deviation of the intracranial manipulation device.

[0093] The processing control device 42 is also used to align the first optical tracker 11 in the anatomical image with the first optical tracker 11 in the optical coordinate system acquired via the optical navigation device 10, thereby registering the anatomical image describing the anatomical structure of the patient's head in the optical coordinate system.

[0094] The processing control device 42 is also used to display two intracranial manipulation instruments that have been positioned and tracked on the display device 41, thereby enabling visualization of the surgical procedure.

[0095] It should be noted that:

[0096] 1. In this invention, by assigning a coordinate system to the relevant instruments or equipment, the pose relationship between the relevant instruments or equipment is described by the pose relationship between the coordinate systems, which is consistent with the way navigation systems and methods in the prior art describe pose relationships.

[0097] 2. In this invention, the optical coordinate system is made to coincide with the coordinate system of the camera 101 in order to minimize the amount of calculation caused by coordinate system transformation.

[0098] 3. In this invention, the pose relationship between related instruments or devices and the pose deviation of the same instrument or device are described by a transformation matrix, which is consistent with the way the navigation system and other aspects describe pose relationships in the prior art.

[0099] In the accompanying diagrams that use transformation matrices to describe the pose of related instruments or equipment, such as Figure 7 , 9 As shown in Figure 11, the coordinate system of the corresponding instrument or equipment is marked on the corresponding instrument or equipment, and the reference numerals of the corresponding instrument or equipment are marked near the coordinate system. These reference numerals represent not only the instrument or equipment itself, but also its coordinate system. Among them, the optical coordinate system is represented by the mark "0".

[0100] In this invention, since the transformation matrix is ​​used to describe and calculate the pose relationship between instruments or devices and / or calibrate pose deviations, it is necessary to define and interpret the expression of the transformation matrix. In the expression of the transformation matrix below and in the accompanying drawings, "T" denotes the basic meaning of the matrix, and the two numbers in the lower right corner of "T" are the reference numerals for the two instruments or devices, separated by a comma. This indicates that the transformation matrix represents the pose between the coordinate systems of the two instruments or devices. For example, as shown... Figure 7 As shown, the transformation matrix expression T 12,31 This indicates the pose of the first device 31 relative to the coordinate system of the second optical tracker 12, that is, the pose of the first device 31 relative to the second optical tracker 12.

[0101] In some expressions of transformation matrices, the upper right corner of "T" has no subscript. These matrix expressions represent poses obtained solely through the optical navigation device 10 based on optical positioning and tracking principles and / or through defined pose relationships, for example, as... Figure 7 As shown, the transformation matrix expression T 0,12 This represents the pose of the second optical tracker 12 in the optical coordinate system, obtained by the optical navigation device 10. For example, the transformation matrix expression T... 12,31 This represents the pose of the first instrument 31 relative to the coordinate system of the second optical tracker 12, obtained based on the determined pose relationship between the first instrument 31 and the second optical tracker 12. For example, the transformation matrix expression T... 0,31 Indicates: The pose T of the second optical tracker 12 in the optical coordinate system obtained by the optical navigation device 10 0,12 The pose T of the coordinate system of the first instrument 31 relative to the coordinate system of the second optical tracker 12, obtained based on the determined pose relationship between the first instrument 31 and the second optical tracker 12. 12,31 The pose of the first instrument 31 in the optical coordinate system obtained by performing calculations.

[0102] In some transformation matrix expressions, "T" has a superscript "'" at its upper right, denoted as "T'". These matrix expressions indicate that there exists at least one pose obtained by electromagnetic navigation device 20 based on the principle of electromagnetic positioning and tracking, for example, such as Figure 7 As shown, the transformation matrix expression T' 23,21 This represents the pose of the first electromagnetic sensor 21, acquired by the electromagnetic navigation device 20, relative to the coordinate system of the magnetic field generator 23. For example, the transformation matrix expression T' 0,32 Indicates: The pose T of the third optical tracker 13 in the optical coordinate system obtained by the optical navigation device 10. 0,13 The pose T of the coordinate system of the magnetic field generator 23 relative to the coordinate system of the third optical tracker 13, obtained based on the determined pose relationship between the magnetic field generator 23 and the third optical tracker 13. 13,23 The pose T' of the first electromagnetic sensor 21 relative to the coordinate system of the magnetic field generator 23, obtained by the electromagnetic navigation device 20. 23,21 The pose T of the second instrument 32 relative to the coordinate system of the first electromagnetic sensor 21 is obtained based on the determined pose relationship between the second instrument 32 and the first electromagnetic sensor 21. 21,32 The pose of the second instrument 32 in the optical coordinate system obtained by the calculation.

[0103] In some transformation matrix expressions, "T" has a superscript "''", denoted as "T''". These matrix expressions represent the pose deviation (or calibration pose) between the pose acquired by the optical navigation device 10 based on the optical positioning and tracking principle and / or determined pose relationship, and the pose acquired by the electromagnetic navigation device 20 based on the electromagnetic positioning and tracking principle, for the same instrument or equipment in the pose acquisition stage. These matrices are called calibration (transformation) matrices. For example, as shown in... Figure 9 As shown, the calibration matrix, T'' 21,21 The pose deviation represents the pose of the first electromagnetic sensor 21 in the optical coordinate system obtained by the optical navigation device 10 and the determined pose relationship, and the pose of the first electromagnetic sensor 21 in the optical coordinate system obtained by the optical navigation device 10, the determined pose relationship, and the electromagnetic navigation device 20.

[0104] This invention also discloses a method for navigating two intracranial manipulation instruments based on the aforementioned navigation system. The two intracranial manipulation instruments used for navigation play the same role as the manipulation instruments described above during the surgical procedure. Specifically, the first instrument 31 and the second instrument 32 are two different types of manipulation instruments. The role of the first instrument 31 during the surgical procedure differs from that of the second instrument 32. Furthermore, the first instrument belongs to a class of instruments that, if not operated accurately, can easily cause serious damage to brain tissue at its distal end. The other instrument (let's call it the second instrument 32) belongs to a class of instruments that, even if operated with low precision, will not cause serious damage to brain tissue. For example, the first instrument 31 is an ultrasonic emulsification aspiration knife (such as a Cusa knife) used to remove brain tumors, and the second instrument 32 is a neuroendoscopy used to guide and expand or enhance the field of vision.

[0105] like Figure 2 As shown, the method for navigating two intracranial manipulation instruments disclosed in this invention includes the following steps:

[0106] like Figure 3 As shown, S10: Obtain an anatomical image of the patient's head with the first optical tracker 11 present, which is used to describe the anatomical structure of the patient's head.

[0107] Before performing this step, the first optical tracker 11 is attached to the patient's head in a fixed manner, for example, by inserting the lower end of the first optical tracker 11 into the skull, thereby fixing the first optical tracker 11 to the patient's head.

[0108] Anatomical images are acquired using methods and procedures that are essentially consistent with existing technologies. For example, the specific steps are as follows:

[0109] S11: Obtain raw medical images.

[0110] Specifically, raw medical images describing the anatomical structure of the patient's head are acquired using equipment such as CT, MRI, and PET scanners. Different modalities of images are selected based on the surgical needs. For example, MRI images are acquired using MRI equipment, which can display gray matter, white matter, tumors, blood vessels, and other tissues at high resolution. T1-weighted sequences in MRI images can be used for brain tissue segmentation and three-dimensional reconstruction, while T2-weighted or FLAIR sequences are used to display edema and the extent of lesions.

[0111] S12: Process the original medical images.

[0112] Specifically, the original medical images are processed individually or in combination as follows, including but not limited to: denoising and standardization, for example, using processing software such as FSL and SPM to eliminate artifacts in the images; multimodal fusion and registration, for example, aligning and fusing images of CT, MRI, etc., in the same coordinate system; segmentation and three-dimensional reconstruction, for example, delineating the boundaries of brain tissue, blood vessels, and lesion areas (e.g., tumors) and constructing three-dimensional models. During segmentation, the optical tracker (not the first optical tracker 11 in this invention) in the image is segmented separately. The purpose is to hide the optical tracker in the anatomical image after registering the anatomical image in the optical coordinate system using the optical tracker to avoid obscuring the cranial entrance, target area (lesion area), surgical path, etc.; and adjusting display parameters, for example, adjusting brightness and contrast, and adding highlight values ​​to highlight the intracranial lesion area.

[0113] S13: Convert and unify the output format of anatomical images.

[0114] Specifically, the post-processed anatomical images are converted into a format that can be recognized and processed by the application in the processing control device 42 of the computer device 40. For example, the format of the anatomical images is converted into DICOM format, so that they can be used in the application of the navigation system and displayed on the display device 41. Figure 5 and Figure 6 An anatomical image is shown on display device 41.

[0115] like Figure 4 As shown, S20: Mark the target area, cranial inlet, and surgical path in the anatomical image to guide the intracranial manipulation instruments (i.e., surgical instruments) to enter the cranium through the cranial inlet and reach the target area along the surgical path.

[0116] This step specifically includes the following processes:

[0117] S21: Based on the obtained anatomical images describing the patient's head, a preliminary surgical approach plan is developed.

[0118] First, before planning the approach, it is necessary to clarify the nature, location, and boundaries of the lesion, for example, based on Figure 5 and Figure 6 The anatomical images shown (the first optical tracker 11 and the coordinate system of the images are hidden in the images) clearly show that the lesion is a glioma. The location and boundary of the glioma can be determined by three-dimensional images, sagittal images, coronal images and transverse images, and its boundary is enhanced by delineating solid lines (or dashed lines).

[0119] Then, a preliminary surgical approach plan is planned based on the nature, location, and boundaries of the lesion. When planning the surgical approach plan, it is necessary to consider issues such as avoiding functional areas of brain tissue and avoiding blood vessels.

[0120] To target excision Figure 5 and Figure 6 Using a glioma on the insula as an example, this step provides two exemplary surgical approaches.

[0121] The first surgical approach: Based on the location and boundaries of the glioma as shown by anatomical images including 3D, sagittal, coronal, and transverse images, and after comprehensively predicting the functional areas and blood vessels of the brain tissue that the glioma might pass through at different cranial entrances, as well as the difficulty of reaching the glioma at different angles for resection, the approach is as follows: Figure 5 As shown, the surgical instruments are inserted through the lateral fissure or insular cortex to remove the glioma from top to bottom. The advantage of this approach is that the distance from the lateral cortex to the insula is shorter. However, the instruments need to pass through the lateral fissure venous network, the functional area of ​​the insular cortex, and the middle cerebral artery network creeping on the surface of the insula. Glioma resection requires avoiding arteries, veins, and functional areas. Therefore, this approach restricts the spatial angle of the surgical operation, increases the difficulty of the operation, and increases the probability of damaging important structures.

[0122] The second surgical approach: Based on the location and boundaries of the glioma as shown by anatomical images including 3D, sagittal, coronal, and transverse images, and after comprehensively assessing the difficulty of reaching the functional areas and blood vessels of the brain tissue that the glioma might pass through at different cranial entrances, as well as the difficulty of reaching the glioma at different angles for resection, the approach is as follows: Figure 6 As shown, the surgical instruments enter the insula from the frontal region, pass through the isthmus to reach the insular glioma, and are removed from the base to the top of the glioma. Although this frontal approach to the insula is a longer surgical path, it avoids the lateral fissure vein, the functional areas of the insular cortex, and the middle cerebral artery network, thus preventing damage to these important structures. Compared to the first approach, this approach has the following advantages: it reduces disturbance to the lateral fissure vein and the middle cerebral artery network, reducing the risk of vasospasm and injury; it avoids the language, motor, and sensory functional areas of the insular cortex, reducing reliance on intraoperative electrophysiological monitoring; and removing the insular glioma from the frontal direction follows the long axis of the glioma, eliminating the need for extensive adjustments to the surgical angle, allowing the entire glioma to be covered in the surgical field, thus improving the glioma resection rate.

[0123] S22: Using an optical navigation probe, accurately plan the cranial entrance and access path in the anatomical image based on the initially planned access scheme. S30: Using the optical navigation device 10, acquire the pose of the first optical tracker 11 in the optical coordinate system, and register the anatomical image in the optical coordinate system based on the pose of the first optical tracker 11 in the optical coordinate system and the pose of the first optical tracker 11 in the image coordinate system of the anatomical image.

[0124] The relative position information of four reflective spheres is obtained in the image obtained by the camera 101 of the optical navigation device 10 taking a picture of the first optical tracker 11. The relative position information of four markers that are consistent with the relative positions of the four reflective spheres are raised in the anatomical image describing the anatomical structure of the head. In this way, by aligning the relative positions of the four markers in the anatomical image with the relative positions of the four reflective spheres in the image obtained by the camera 101, the alignment of the first optical tracker 11 in the anatomical image with the first optical tracker 11 in the optical coordinate system is completed, thereby realizing the registration of the anatomical image in the optical coordinate system.

[0125] S40: The pose of the second optical tracker 12 in the optical coordinate system is obtained using the optical navigation device 10; the pose of the third optical tracker 13 in the optical coordinate system is obtained using the optical navigation device 10 and the pose of the first electromagnetic sensor 21 relative to the magnetic field generator 23 is obtained using the electromagnetic navigation device 20; the pose of the first electromagnetic sensor 21 in the optical coordinate system is obtained based on the pose of the third optical tracker 13 in the optical coordinate system, the pose relationship between the magnetic field generator 23 and the third optical tracker 13, and the pose of the first electromagnetic sensor 21 relative to the magnetic field generator 23.

[0126] The purpose of this step is to simultaneously (or synchronously) acquire the poses of the second optical tracker 12 and the first electromagnetic sensor 21 in the optical coordinate system. Thus, based on the determined pose relationship between the first device 31 and the second optical tracker 12, and the determined pose relationship between the second device 32 and the first electromagnetic sensor 21, the poses of the first device 31 and the second device 32 in the optical coordinate system can be obtained simultaneously. Finally, without the second device 32 being equipped with an optical tracker, the positioning and tracking (i.e., navigation) of the two intracranial manipulation devices (i.e., the first device 31 and the second device 32) can be achieved.

[0127] The method for obtaining the attitude of the second optical tracker 12 in the optical coordinate system is as follows: using the optical navigation device 10 and based on the optical positioning and tracking principle, the attitude T of the coordinate system of the second optical tracker 12 in the optical coordinate system is directly obtained. 0,12 .

[0128] like Figure 7As shown, the method for obtaining the attitude of the first electromagnetic sensor 21 in the optical coordinate system is as follows: First, the pose T of the coordinate system of the third optical tracker 13 in the optical coordinate system is obtained using the optical navigation device 10 and based on the optical positioning and tracking principle. 0,13 And using the electromagnetic navigation device 20 and based on the electromagnetic positioning and tracking principle, the pose T' of the coordinate system of the first electromagnetic sensor 21 relative to the coordinate system of the magnetic field generator 23 is obtained. 23,21 Then, using the processing and control device 42, the pose T of the coordinate system of the third optical tracker 13 in the optical coordinate system is... 0,13 The pose T of the magnetic field generator 23 relative to the coordinate system of the third optical tracker 13 stored in the processing control device 42 13,23 The pose T' of the coordinate system of the first electromagnetic sensor 21 relative to the coordinate system of the magnetic field generator 23 23,21 The attitude T' of the first electromagnetic sensor 21 in the optical coordinate system is obtained by performing calculations. 0,21 That is, T' 0,21 =T 0,13 *T 13,23 *T' 23,21 .

[0129] The significant feature of this step is that the first instrument 31 and the second instrument 32 are simultaneously navigated by operating the electromagnetic navigation device 20 and the optical navigation device 10 at the same time. Furthermore, the navigation of the second instrument 32 is achieved by the optical navigation device 10 and the electromagnetic navigation device 20 cooperating to obtain the pose of the first electromagnetic sensor 21 in the optical coordinate system. This avoids the need to configure an optical tracker on the second instrument 32 for navigation. As a result, the probability of the second optical tracker 12 on the first instrument 31 being blocked by the second instrument 32 and the probability of mutual mechanical interference are significantly reduced because it is not necessary to configure an optical tracker on the second instrument 32. This reduces the probability of the navigation of the operating instruments being interrupted due to blocking and significantly increases the range of motion of the two operating instruments.

[0130] S50: Calibrate the pose of the first electromagnetic sensor 21.

[0131] like Figures 8 to 11 and combined Figure 7 As shown, the pose T' of the first electromagnetic sensor 21 in the optical coordinate system is obtained. 0,21 During the process, the pose T' of the first electromagnetic sensor 21 relative to the magnetic field generator 23 is obtained by the electromagnetic navigation device 20 based on the electromagnetic positioning and tracking principle. 23,21In this process, although the present invention minimizes or reduces magnetic field distortion and the pose deviation caused by magnetic field distortion by configuring a homogeneous operating table 50 and placing the magnetic field generator 23 on the front side of the operating table 50 near the head, the pose obtained based on the electromagnetic positioning and tracking principle still has deviations because magnetic field distortion cannot be completely eliminated. Therefore, during the navigation of the first instrument 31 and the second instrument 32, the pose T' of the coordinate system of the first electromagnetic sensor 21 on the second instrument 32 in the optical coordinate system can be determined. 0,21 Calibration can be performed, and the calibration method can be summarized as follows: obtain the calibration matrix T'' 21,21 The processing and control device 42 uses the position T' of the first electromagnetic sensor 21's coordinate system in the optical coordinate system to determine its pose. 0,21 With calibration matrix T' 0,21 The calibrated pose T' is obtained by performing calculations. 0,21 *T'' 21,21 The pose T' of the calibrated first electromagnetic sensor 21 in the optical coordinate system 0,21 *T'' 21,21 Compared to the pose T' before calibration 0,21 This improves accuracy, thereby enhancing the navigation precision of the second instrument 32. Two specific methods for calibrating the pose of the first electromagnetic sensor 21 in the optical coordinate system are provided below.

[0132] S60: The pose of the first instrument 31 in the optical coordinate system is obtained based on the pose of the second optical tracker 12 in the optical coordinate system and the pose relationship between the second optical tracker 12 and the first instrument 31; the calibrated pose of the second instrument 32 in the optical coordinate system is obtained based on the calibrated pose of the first electromagnetic sensor 21 in the optical coordinate system and the pose relationship between the first electromagnetic sensor 21 and the second instrument 32; navigation of the first instrument 31 and the second instrument 32 is performed based on the obtained poses and visualized in the anatomical image.

[0133] Specifically, the processing and control device 42 is used to process the pose T of the second optical tracker 12's coordinate system in the optical coordinate system. 0,12 The pose T of the first instrument 31 relative to the coordinate system of the second optical tracker 12 stored in the processing control device 42 12,31 The pose T of the first instrument 31 in the optical coordinate system is obtained by performing calculations. 0,31 =T 0,12 *T 12,31 The pose T' of the calibrated first electromagnetic sensor 21's coordinate system in the optical coordinate system. 0,21 *T'' 21,21The pose T of the second instrument 32 relative to the coordinate system of the first electromagnetic sensor 21 stored in the processing and control device 42 21,32 The pose T' of the calibrated first instrument 31 in the optical coordinate system is obtained by performing calculations. 0,21 *T'' 21,21 *T 21,32 .

[0134] In the display device 41, navigation is performed on the first instrument 31 and the second instrument 32 based on the obtained poses of the first instrument 31 and the second instrument 32, and the first instrument 31 and the second instrument 32, unified to the optical coordinate system, are displayed in the anatomical image describing the anatomical structure of the head, so as to realize the visualization of the first instrument 31 and the second instrument 32 in the anatomical image.

[0135] Two methods for calibrating the pose of the first electromagnetic sensor 21 in the optical coordinate system are provided below.

[0136] like Figure 8 and Figure 9 As shown, a first method for calibrating the pose of the first electromagnetic sensor 21 in an optical coordinate system.

[0137] Before implementing this method, the first instrument 31 and the second instrument 32 need to be configured in the following mechanical engagement manner:

[0138] The first device 31 and the second device 32 can be rigidly and separably attached, and in the attached state, the first device 31 and the second device 32 have a defined positional relationship.

[0139] To achieve the above-mentioned cooperation method, the following structure is added to the first instrument 31 and the second instrument 32:

[0140] A first positioning structure is configured on the first instrument 31, and a second positioning structure is configured on the second instrument 32. The first instrument 31 and the second instrument 32 can be detachably attached through the first positioning structure and the second positioning structure. Specifically, two first positioning rings, each with a positioning recess, are fixedly sleeved on the outer peripheral surface of the proximal region of the first instrument 31, and two first positioning rings, each with a positioning protrusion, are fixedly sleeved on the outer peripheral surface of the proximal region of the second instrument 32. By inserting the two positioning protrusions into the two positioning recesses respectively, the first instrument 31 and the second instrument 32 are attached in a rigid, detachable manner and with a defined positional relationship. Furthermore, the positional relationship data between the first instrument 31 and the second instrument 32 is stored in the processing and control device 42.

[0141] like Figure 8 and Figure 9As shown, the first method for calibrating the pose of the first electromagnetic sensor 21 in the optical coordinate system provided by the present invention includes the following steps:

[0142] S51: The pose of the first electromagnetic sensor 21 relative to the second optical tracker 12 is obtained based on the pose relationship between the first instrument 31 and the second instrument 32 in the attached state.

[0143] Specifically, at least before the distal ends of the first device 31 and the second device 32 enter the cranial cavity through the cranial inlet, the first device 31 and the second device 32 are attached once. In the attached state, due to the pose T of the coordinate system of the first electromagnetic sensor 21 relative to the coordinate system of the second device 32... 32,21 The pose T of the coordinate system of the second instrument 32 relative to the coordinate system of the first instrument 31 31,32 The pose T of the coordinate system of the first device 31 relative to the coordinate system of the second optical tracker 12 12,31 Known and pre-stored in the processing control device 42, the pose T of the coordinate system of the first electromagnetic sensor 21 relative to the coordinate system of the second instrument 32 is then determined using the processing control device 42. 32,21 The pose T of the coordinate system of the second instrument 32 relative to the coordinate system of the first instrument 31 31,32 The pose T of the coordinate system of the first device 31 relative to the coordinate system of the second optical tracker 12 12,31 By performing calculations, the pose T of the coordinate system of the first electromagnetic sensor 21 relative to the coordinate system of the second optical tracker 12 can be obtained. 12,21 =T 32,21 *T 31,32 *T 12,31 .

[0144] Preferably, such as Figure 9 As shown, the first electromagnetic sensor 21 is attached to the distal region of the second instrument 32. Specifically, for example, the first electromagnetic sensor 21 is attached to the inner side of the tube wall in the distal region. If the first electromagnetic sensor 21 can be arranged in the distal region of the second instrument 32, then after the distal ends of the first instrument 31 and the second instrument 32 reach the lesion in the cranium through the cranial inlet and before the lesion is treated, the first instrument 31 and the second instrument 32 can be attached again. The advantages of attaching the first instrument 31 and the second instrument 32 again at this stage will be explained below.

[0145] S52: The pose of the first electromagnetic sensor 21 in the optical coordinate system obtained from the pose of the first electromagnetic sensor 21 relative to the second optical tracker 12 in the attached state and the pose of the second optical tracker 12 in the optical coordinate system obtained by the optical navigation device 10 is used as the reference pose.

[0146] Specifically, in the attached state, the processing and control device 42 uses the obtained pose T of the first electromagnetic sensor 21 coordinate system relative to the second optical tracker 12 coordinate system to... 12,21 The pose T of the second optical tracker 12 in the optical coordinate system obtained by the optical navigation equipment 0,12 The pose T of the first electromagnetic sensor 21 in the optical coordinate system is obtained by performing calculations. 0,21 = T 12,21 * T 0,12 This pose T 0,21 As a reference pose.

[0147] It should be noted that the reference pose described in this step and below is obtained by calculating the pose obtained by the optical navigation device 10 based on the optical positioning and tracking principle and the pose obtained based on the determined pose relationship between the relevant instruments or devices. The reason for using the pose obtained by calculating the pose obtained based on the optical positioning and tracking principle and the pose obtained based on the determined pose relationship as the reference pose is that the pose obtained based on the optical positioning and tracking principle and the pose obtained based on the determined pose relationship are more accurate than the pose obtained by the electromagnetic navigation device 20 based on the electromagnetic positioning and tracking principle. Therefore, the reference pose is used as the benchmark for calibrating the pose.

[0148] S53: The pose of the first electromagnetic sensor 21 in the optical coordinate system obtained by the optical navigation device 10 in the attached state, the pose relationship between the magnetic field generator 23 and the third optical tracker 13, and the pose of the first electromagnetic sensor 21 relative to the magnetic field generator 23 obtained by the electromagnetic navigation device 20 are used as the pose to be calibrated.

[0149] Specifically, in the attached state, the processing and control device 42 uses the coordinate system of the third optical tracker 13, which is acquired by the optical navigation device 10, to determine its pose T in the optical coordinate system. 0,13 The pose T of the magnetic field generator 23 relative to the coordinate system of the third optical tracker 13 stored in the processing device. 13,23 The pose T' of the first electromagnetic sensor 21 relative to the coordinate system of the magnetic field generator 23, obtained by the electromagnetic navigation device 20. 23,21 The pose T' of the first electromagnetic sensor 21 in the optical coordinate system obtained by performing calculations 0,21 = T 0,13 * T 13,23 * T' 23,21 Due to the pose T' of the coordinate system of the first electromagnetic sensor 21 in the optical coordinate system 0,21 There exists a principle for obtaining pose T' based on electromagnetic positioning and tracking.23,21 In this process, due to magnetic field distortion, the pose obtained based on the electromagnetic positioning and tracking principle has deviations. Therefore, the pose T' is... 0,21 As the pose to be calibrated.

[0150] S54: Obtain a calibration matrix based on the pose to be calibrated and the reference pose of the first electromagnetic sensor 21, and use the calibration matrix to calibrate the pose of the first electromagnetic sensor 21 in the optical coordinate system.

[0151] Specifically, the processing and control device 42 uses the coordinate system of the first electromagnetic sensor 21 to establish the reference pose T in the optical coordinate system. 0,21 The pose T' to be calibrated in the optical coordinate system relative to the coordinate system of the first electromagnetic sensor 21. 0,21 The calibration matrix T'' is obtained by performing calculations. 21,21 = T 0,21 * (- T' 0,21 Then, the calibration matrix T'' 21,21 The pose of the first electromagnetic sensor 21 and the second instrument 32 is calculated in real time by combining the pose of the first electromagnetic sensor 21 in the optical coordinate system.

[0152] In fact, the calibration matrix obtained by the above method characterizes and quantifies the difference between the distorted magnetic field and the preset magnetic field to a certain extent. For example, the calibration matrix characterizes and quantifies the difference in the density of magnetic field lines before and after local distortion, or the overall offset of magnetic field lines before and after magnetic field shift. Therefore, the process of pose calibration is also a process of correcting magnetic field distortion. Thus, when the second instrument 32 cooperates with the first instrument 31 to perform treatment on the lesion, by using the calibration matrix T'' 21,21 Calibrling the first electromagnetic sensor 21 and the second instrument 32 can improve the accuracy of navigation of the second instrument 32 to a certain extent.

[0153] The aforementioned preferred method of attaching the first electromagnetic sensor 21 to the distal region of the second instrument 32, and preferably attaching the first instrument 31 and the second instrument 32 again after the distal ends of the first instrument 31 and the second instrument 32 have reached the intracranial lesion through the cranial inlet and before treating the lesion, to obtain the calibration matrix of the magnetic field region (the region where the first electromagnetic sensor 21 is located) of the first electromagnetic sensor 21, has the advantage that: in fact, when treating the lesion, the accurate positioning and tracking of the distal ends of the two operating instruments is the key to accurate treatment of the lesion. If the first electromagnetic sensor 21 is placed at the proximal end of the second instrument 32, because the two intracranial operating instruments are rod-shaped instruments, the distance between the first electromagnetic sensor 21 and the distal end is relatively large, and because the second instrument 32 inevitably depends on the second instrument 32 after calibration, the first electromagnetic sensor 21 will be far from the distal end. However, there is a positional deviation (the positional deviation of the device after calibration by the calibration matrix is ​​reduced but difficult to completely eliminate). Therefore, the positional deviation of the second device 32 after calibration will increase after being converted to the distal end. However, if the first electromagnetic sensor 21 is placed near the distal end of the second device 32, the positional deviation will not change much after being converted to the end. The reason for recalibrating the second device 32 after reaching the lesion is that the magnetic field distortion in the lesion area may be different from that in its surrounding area (e.g., the extracranial area), and the obtained calibration matrix may be different. Using the calibration matrix obtained near the lesion area to calibrate the first device 31 for the treatment operation is beneficial to reduce the positional deviation of the first device 31 during the treatment operation.

[0154] The second method for calibrating the pose of the first electromagnetic sensor 21 in the optical coordinate system.

[0155] Before implementing this method, the second electromagnetic sensor 22, which is used to obtain the pose based on the electromagnetic positioning and tracking principle, is placed on the first instrument 31 or in an area that has a defined pose relationship with the first optical tracker 11 (e.g., directly placed on the first optical tracker 11 or placed on the patient's head).

[0156] like Figure 10 and Figure 11 As shown, the second method for calibrating the pose of the first electromagnetic sensor 21 in the optical coordinate system provided by the present invention includes the following steps:

[0157] S51': The pose of the second electromagnetic sensor 22 in the optical coordinate system obtained based on the pose of the first optical tracker 11 or the second optical tracker 12 in the optical coordinate system is used as the reference pose of the second electromagnetic sensor 22.

[0158] In this step, the reference pose of the second electromagnetic sensor 22 in the optical coordinate system can be obtained in two ways.

[0159] The first method is to obtain the reference pose of the second electromagnetic sensor 22 in the optical coordinate system based on the pose of the second optical tracker 12 in the optical coordinate system. Specifically, the second electromagnetic sensor 22 is attached to the first device 31 with a predetermined pose relationship, and the pose T of the second optical tracker 12 in the optical coordinate system obtained by the optical navigation device 10 is processed by the processing and control device 42. 0,12 The pose T of the second electromagnetic sensor 22 relative to the second optical tracker 12 12,22 The reference pose T of the second electromagnetic sensor 22 in the optical coordinate system is obtained by performing calculations. 0,22 = T 0,12 * T 12,22 In this approach, preferably, the second electromagnetic sensor 22 is attached to the distal region of the first instrument 31, and the first electromagnetic sensor 21 is attached to the distal region of the second instrument 32. The advantages of arranging the two electromagnetic sensors in this way will be described below.

[0160] The second method is to obtain the reference pose of the second electromagnetic sensor 22 in the optical coordinate system based on the pose of the first optical tracker 11 in the optical coordinate system. Specifically, the second electromagnetic sensor 22 is attached to the first optical tracker 11 in a predetermined pose relationship (or attached to the head of a patient with a predetermined pose relationship to the first optical tracker 11), and the processing and control device 42 uses the pose T of the first optical tracker 11 in the optical coordinate system obtained by the optical navigation device 10 to obtain the reference pose T of the first optical tracker 11 in the optical coordinate system. 0,11 The pose T of the coordinate system of the second electromagnetic sensor 22 relative to the coordinate system of the first optical tracker 11 11,22 The reference pose T of the second electromagnetic sensor 22 in the optical coordinate system is obtained by performing calculations. 0,22 =T 0,11 * T 11,22 In this approach, specifically, the second electromagnetic sensor 22 is attached to the first optical tracker 11, and the first electromagnetic sensor 21 is attached to the proximal region of the second device 32, so as to be as close as possible to the first electromagnetic sensor 21.

[0161] S52': The pose of the second electromagnetic sensor 22 in the optical coordinate system obtained based on the pose of the magnetic field generator 23 in the optical coordinate system and the pose of the second electromagnetic sensor 22 relative to the magnetic field generator 23 obtained by the electromagnetic navigation device 20 is taken as the pose to be calibrated of the second electromagnetic sensor 22.

[0162] Specifically, the processing and control device 42 uses the coordinate system of the third optical tracker 13, acquired by the optical navigation device 10, to determine its pose T in the optical coordinate system. 0,13Pose T of the coordinate system of the magnetic field generator 23 relative to the coordinate system of the third optical tracker 13 13,23 The position T of the magnetic field generator 23 in the optical coordinate system is obtained by calculation. 0,23 =T 0,13 * T 13,23 The coordinate system of the obtained magnetic field generator 23 is used by the processing and control device 42 to determine its pose T in the optical coordinate system. 0,23 The pose T' of the second electromagnetic sensor 22 relative to the coordinate system of the magnetic field generator 23, obtained by the electromagnetic navigation device 20. 23,22 The pose T' of the second electromagnetic sensor 22 in the optical coordinate system is obtained by performing calculations. 0,22 = T 0,23 * T' 23,22 This pose is used as the pose to be calibrated for the second electromagnetic sensor 22.

[0163] S53': The pose of the first electromagnetic sensor 21 in the optical coordinate system, obtained from the pose of the magnetic field generator 23 in the optical coordinate system and the pose of the first electromagnetic sensor 21 relative to the magnetic field generator 23 obtained by the electromagnetic navigation device 20, is taken as the pose to be calibrated of the first electromagnetic sensor 21.

[0164] Specifically, the processing and control device 42 uses the coordinate system of the third optical tracker 13, acquired by the optical navigation device 10, to determine its pose T in the optical coordinate system. 0,13 Pose T of the coordinate system of the magnetic field generator 23 relative to the coordinate system of the third optical tracker 13 13,23 The position T of the magnetic field generator 23 in the optical coordinate system is obtained by calculation. 0,23 =T 0,13 * T 13,23 The coordinate system of the obtained magnetic field generator 23 is used by the processing and control device 42 to determine its pose T in the optical coordinate system. 0,23 The pose T' of the first electromagnetic sensor 21 relative to the coordinate system of the magnetic field generator 23, obtained by the electromagnetic navigation device 20. 23,21 The pose T' of the first electromagnetic sensor 21 in the optical coordinate system is obtained by performing calculations. 0,21 = T 0,23 * T' 23,21 This pose is used as the pose to be calibrated for the first electromagnetic sensor 21.

[0165] S54': A calibration matrix is ​​obtained based on the pose to be calibrated and the reference pose of the second electromagnetic sensor 22, and the pose to be calibrated of the first electromagnetic sensor 21 is calibrated using the calibration matrix.

[0166] Specifically, the processing and control device 42 is used to transfer the reference pose T of the coordinate system of the second electromagnetic sensor 22 in the optical coordinate system. 0,22 The pose T' to be calibrated in the optical coordinate system is compared with the coordinate system of the second electromagnetic sensor 22 that has already been obtained. 0,22 The calibration matrix T'' is obtained by performing calculations. 22,22 = T 0,22 * (-T' 0,22 Then, the calibration matrix T'' 22,22 The pose of the first electromagnetic sensor 21, obtained in real time, is calculated in the optical coordinate system in real time, T'. 0,21 =T' 0,21 *T'' 22,22 This allows for real-time calibration of the pose of the first electromagnetic sensor 21 and the second instrument 32.

[0167] The principle of this method for calibrating the pose of the first electromagnetic sensor 21 can be summarized as follows: A calibration matrix is ​​obtained by calculating the pose of the second electromagnetic sensor 22 in the optical coordinate system, obtained solely based on optical positioning and tracking principles and a determined pose relationship, and the pose of the second electromagnetic sensor 22 in the optical coordinate system obtained with the participation of electromagnetic tracking and positioning principles. This calibration matrix is ​​then used to calibrate the pose of the first electromagnetic sensor 21. More specifically, the pose deviation of the second electromagnetic sensor 22 between the two pose acquisition methods is used as calibration matrix two to calibrate the pose of the first electromagnetic sensor 21.

[0168] In the second calibration method, the first method is superior to the second method because: In the first method, both electromagnetic sensors can be arranged in the distal regions of the two instruments. Thus, the two electromagnetic sensors are close to each other and are basically (or highly likely) in the magnetic field region with the same distortion. Therefore, the pose deviation of the second electromagnetic sensor 22 is highly consistent with the pose deviation of the first electromagnetic sensor 21. Consequently, the calibration matrix obtained based on the pose deviation of the second electromagnetic sensor 22 has high accuracy in calibrating the pose of the first electromagnetic sensor 21. However, in the second method, since the second electromagnetic sensor 22 is arranged in the first optical tracker 11 (or the patient's head), the positions of the first electromagnetic sensor 21 and the second electromagnetic sensor 22 on the second instrument 32 are far apart. This may result in different distortions in the magnetic field regions where the first electromagnetic sensor 21 and the second electromagnetic sensor 22 are located. This may lead to lower accuracy in calibrating the pose of the first electromagnetic sensor 21 based on the pose deviation of the second electromagnetic sensor 22 than in the first method.

[0169] In the second approach, the second electromagnetic sensor 22 can be configured in the WeChat gimbal. The micro-drive component (e.g., micro motor) in the WeChat gimbal drives the second electromagnetic sensor 22 to adjust its attitude, so that the attitude of the second electromagnetic sensor 22 is consistent with that of the first electromagnetic sensor 21 obtained by the electromagnetic navigation device 20 in the optical coordinate system in real time. Thus, the first electromagnetic sensor 21 is calibrated based on the calibration matrix obtained by the second electromagnetic sensor 22. This helps to reduce the reduction in calibration accuracy caused by the excessive spatial angle between the two electromagnetic sensors.

Claims

1. A method for navigating two intracranial manipulation instruments, the two manipulation instruments comprising a first instrument and a second instrument, characterized in that, A first optical tracker is attached to the surgical site; a second optical tracker and a first electromagnetic sensor are attached to the first and second instruments respectively in a defined pose relationship; a third optical tracker has a defined pose relationship with a magnetic field generator; the first instrument has a greater potential to cause damage to intracranial tissue than the second instrument; the method includes: Obtain anatomical images describing the anatomical structures of the surgical site; Mark the target area, cranial entrance, and surgical path in the anatomical images; The pose of the first optical tracker in the optical coordinate system is obtained using an optical navigation device, and the anatomical image is registered in the optical coordinate system based on the pose of the first optical tracker in the optical coordinate system and its pose in the image coordinate system of the anatomical image. The poses of the second and third optical trackers in the optical coordinate system are obtained using an optical navigation device, and the pose of the first electromagnetic sensor relative to the magnetic field generator is obtained using an electromagnetic navigation device. Based on the pose of the third optical tracker in the optical coordinate system, the pose relationship between the magnetic field generator and the third optical tracker, and the pose of the first electromagnetic sensor relative to the magnetic field generator, the pose of the first electromagnetic sensor in the optical coordinate system is obtained. The pose of the first electromagnetic sensor is calibrated; Based on the pose relationship between the second optical tracker and the first instrument and the pose relationship between the first electromagnetic sensor and the second instrument, the pose of the first instrument in the optical coordinate system and the calibrated pose of the second instrument in the optical coordinate system are obtained, and the first and second instruments are visualized in the anatomical image. The first instrument and the second instrument can be rigidly and separably attached, and in the attached state, the first instrument and the second instrument have a defined positional relationship. The calibration of the pose of the first electromagnetic sensor includes: The pose of the first electromagnetic sensor relative to the second optical tracker is obtained based on the pose relationship between the first and second instruments in the attached state. The pose of the first electromagnetic sensor in the optical coordinate system, obtained from the pose of the first electromagnetic sensor relative to the second optical tracker in the attached state and the pose of the second optical tracker in the optical coordinate system obtained by the optical navigation device, is used as the reference pose. The pose of the first electromagnetic sensor in the optical coordinate system obtained by the optical navigation device in the attached state, the pose relationship between the magnetic field generator and the third optical tracker, and the pose of the first electromagnetic sensor relative to the magnetic field generator obtained by the electromagnetic navigation device are used as the pose to be calibrated. A calibration matrix is ​​obtained based on the pose to be calibrated and the reference pose of the first electromagnetic sensor, and the pose of the first electromagnetic sensor in the optical coordinate system is calibrated using the calibration matrix. The second electromagnetic sensor is placed at or near the surgical site; The calibration of the pose of the first electromagnetic sensor includes: The pose of the second electromagnetic sensor in the optical coordinate system, obtained based on the pose of the first or second optical tracker in the optical coordinate system, is used as the reference pose of the second electromagnetic sensor. The pose of the second electromagnetic sensor in the optical coordinate system, obtained from the pose of the magnetic field generator in the optical coordinate system and the pose of the second electromagnetic sensor relative to the magnetic field generator obtained by the electromagnetic navigation device, is taken as the pose to be calibrated of the second electromagnetic sensor. The pose of the first electromagnetic sensor in the optical coordinate system, obtained from the pose of the magnetic field generator in the optical coordinate system and the pose of the first electromagnetic sensor relative to the magnetic field generator obtained by the electromagnetic navigation device, is taken as the pose to be calibrated of the first electromagnetic sensor. A calibration matrix is ​​obtained based on the pose to be calibrated and the reference pose of the second electromagnetic sensor, and the pose to be calibrated of the first electromagnetic sensor is calibrated using the calibration matrix. The second electromagnetic sensor is attached to the distal region of the first device in a manner that forms a defined pose relationship with the second optical tracker, and the first electromagnetic sensor is attached to the distal region of the second device. The reference pose of the second electromagnetic sensor in the optical coordinate system, obtained based on the pose of the second optical tracker in the optical coordinate system, includes: The reference pose of the second electromagnetic sensor in the optical coordinate system is obtained based on the pose of the second optical tracker in the optical coordinate system obtained by the optical navigation device and the pose relationship between the second electromagnetic sensor and the second optical tracker.

2. The method according to claim 1, characterized in that, The second electromagnetic sensor and the first optical tracker have a defined pose relationship; The reference pose of the second electromagnetic sensor in the optical coordinate system, obtained based on the pose of the first optical tracker in the optical coordinate system, includes: The reference pose of the second electromagnetic sensor in the optical coordinate system is obtained based on the pose of the first optical tracker in the optical coordinate system acquired by the optical navigation device and the pose relationship between the second electromagnetic sensor and the first optical tracker.

3. A navigation system for surgical navigation of two intracranial manipulation instruments, the two manipulation instruments comprising a first instrument and a second instrument, characterized in that, The navigation system includes an image acquisition device, a navigation instrument, and a computer device. The first instrument has a greater potential damage to intracranial tissues than the second instrument. The navigation device includes an optical navigation device, a first, second, and third optical tracker, an electromagnetic navigation device, and a first electromagnetic sensor; Computer equipment includes processing and control equipment and display equipment; The first optical tracker is attached to the surgical site, the second optical tracker and the first electromagnetic sensor are attached to the first and second instruments respectively in a defined pose relationship, and the third optical tracker is attached to the periphery of the surgical site and has a defined pose relationship with the magnetic field generator. Image acquisition devices are used to acquire raw images that describe the anatomical structures of the surgical site; The optical navigation device is used to acquire the pose of the first, second, and third optical trackers in the optical coordinate system; The electromagnetic navigation device is used to obtain the pose of the first electromagnetic sensor relative to the magnetic field generator; The processing and control equipment is used for: The image to be processed is converted into an anatomical image; The anatomical image is registered in the optical coordinate system based on the pose of the first optical tracker in the optical coordinate system and its pose in the image coordinate system of the anatomical image. The pose of the first instrument in the optical coordinate system is calculated based on the pose of the second optical tracker in the optical coordinate system and its pose relationship with that of the first instrument. The pose of the second instrument in the optical coordinate system is calculated based on the pose of the third optical tracker in the optical coordinate system, the pose relationship between the magnetic field generator and the third optical tracker, the pose of the first electromagnetic sensor relative to the magnetic field generator, and the pose relationship with the second instrument. The pose of the first electromagnetic sensor is calibrated; The display device is used to visualize the first and second instruments in the anatomical images; The first instrument has a first positioning structure, and the second instrument has a second positioning structure. The first instrument and the second instrument can be detachably attached through the first positioning structure and the second positioning structure. In the attached state, the first instrument and the second instrument have a definite positional relationship. The processing control device is used for: The pose of the first electromagnetic sensor relative to the second optical tracker is calculated based on the pose relationship between the first and second instruments in the attached state; the pose of the first electromagnetic sensor in the optical coordinate system is calculated based on the pose of the first electromagnetic sensor relative to the second optical tracker in the attached state and the pose of the second optical tracker in the optical coordinate system, and is used as the reference pose. The pose of the first electromagnetic sensor in the optical coordinate system is calculated based on the pose of the third optical tracker in the attached state, the pose relationship between the magnetic field generator and the third optical tracker, and the pose of the first electromagnetic sensor relative to the magnetic field generator, and is used as the pose to be calibrated. The calibration matrix is ​​calculated based on the pose to be calibrated and the reference pose of the first electromagnetic sensor, and the pose of the first electromagnetic sensor in the optical coordinate system is calibrated using the calibration matrix. The navigation device also includes a second electromagnetic sensor, which is disposed at or near the surgical site. The processing control device is used for: The pose of the second electromagnetic sensor in the optical coordinate system is calculated based on the pose of the first or second optical tracker in the optical coordinate system obtained by the optical navigation device and used as the reference pose; the pose of the second electromagnetic sensor in the optical coordinate system is calculated based on the pose of the magnetic field generator in the optical coordinate system and the pose of the second electromagnetic sensor relative to the magnetic field generator obtained by the electromagnetic navigation device and used as the pose to be calibrated; the pose of the first electromagnetic sensor in the optical coordinate system is calculated based on the pose of the magnetic field generator in the optical coordinate system and the pose of the first electromagnetic sensor relative to the magnetic field generator obtained by the electromagnetic navigation device and used as the pose to be calibrated. A calibration matrix is ​​calculated based on the pose to be calibrated and the reference pose of the second electromagnetic sensor, and the pose to be calibrated of the first electromagnetic sensor is calibrated using the calibration matrix. The first electromagnetic sensor is arranged in the distal region of the second instrument, and the second electromagnetic sensor is arranged in the distal region of the first instrument.

4. The navigation system according to claim 3, characterized in that, The first electromagnetic sensor is disposed in the proximal region of the second device, and the second electromagnetic sensor is disposed on the first optical tracker.

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