Tracking device and method of using same

Abstract

A tracking device and a method of using the same. The device includes a sensor that generates an inertial signal. The device also includes a controller in communication with the sensor. The controller determines a first position based on the inertial signal relative to the registered position.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit and priority of U.S. Provisional Patent Application No. 63 / 492,610, filed March 28, 2023, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to surgical navigation, and more particularly to a system for determining the location of equipment (such as tools) during surgery. Background Technology

[0004] This section provides background information in connection with this disclosure, which is not necessarily prior art.

[0005] Image-guided medical and surgical procedures utilize patient images acquired before or during the procedure to guide physicians in performing the surgery. Recent advances in imaging technologies, particularly those producing highly detailed two-dimensional, three-dimensional, and four-dimensional images (e.g., over time) such as computed tomography (CT), magnetic resonance imaging (MRI), fluorescence microscopy (e.g., using C-arm devices), positron emission tomography (PET), and ultrasound imaging (US), have generated increasing interest in image-guided medical procedures.

[0006] Guiding tools relative to patient positioning is crucial. Medical device companies use technologies such as optical or electromagnetic (EM) navigation to help surgical teams accurately position tools within the patient during surgery and create visibility in inaccessible areas. While both methods offer exceptional accuracy, they can have their own limitations. For optical navigation, the potential loss of vision by the optical sensor (camera) is one example of a limitation. For EM navigation, the presence of interference in the EM field (such as that caused by metal) can limit its accuracy. Summary of the Invention

[0007] This section provides an overall overview of this disclosure and is not a complete disclosure of its full scope or all of its features.

[0008] This disclosure uses a triaxial accelerometer and gyroscope to create an independent surgical navigation technique that enables the determination of the tool's location and trajectory without the limitations described above for other navigation methods.

[0009] In one aspect of this disclosure, a tracking device includes a sensor that generates an inertial signal. The device also includes a controller in communication with the sensor. The controller determines a first position based on the inertial signal relative to a registration position.

[0010] In another aspect of this disclosure, a method includes: determining a registration location for an object; generating an accelerometer signal based on the movement of the object at a sensor coupled to the object; transmitting the accelerometer signal from the sensor to a controller; and using the controller to determine a first location based on the accelerometer signal and the registration location.

[0011] Further areas of applicability will become apparent from the description provided herein. The descriptions and specific examples in this overview are intended for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0012] The accompanying drawings described herein are for illustrative purposes only for the selected embodiments, and not for all possible specific implementations, and are not intended to limit the scope of this disclosure.

[0013] Figure 1A It is an environmental view in the operating room using a tool tracking system according to this disclosure;

[0014] Figure 1B yes Figure 1A A simplified block diagram representing the interaction of the tracking system;

[0015] Figure 2 This is a block diagram view of the tools of this disclosure relative to the controller;

[0016] Figure 3 It is a diagram of vector paths according to this disclosure;

[0017] Figure 4 It is a composite form of tool paths with various segments D1 to Dn;

[0018] Figure 5 It is the actual form of the origin and path in the coordinate system;

[0019] Figure 6 This is a flowchart of a method for performing displacement determination;

[0020] Figure 7 It is a flowchart of a method for determining the trajectory and location of a tool in various segments; and

[0021] Figure 8 This is a flowchart of a method for determining location based on the interaction of various tracking systems.

[0022] In several views of all the accompanying drawings, the corresponding reference numerals indicate the corresponding components. Detailed Implementation

[0023] Exemplary embodiments will now be described more fully with reference to the accompanying drawings.

[0024] This subject matter discloses exemplary embodiments of surgical procedures performed on subjects, such as human bodies or patients. However, it should be understood that the systems and methods described herein are merely exemplary and are not intended to limit the scope of the claims included herein. In various embodiments, it should be understood that the systems and methods can be incorporated into and / or used on non-living objects. Therefore, the exemplary descriptions of surgical procedures herein are not intended to limit the scope of the appended claims.

[0025] Figure 1A This is an illustrative view illustrating an overview of an operating room or surgical environment. In various embodiments, the operating room may include a surgical suite having a navigation system 26 usable relative to a subject, which may be a human body or a patient 30. The navigation system 26 may be used to track the position of one or more tracking devices. The tracking devices may be associated with one or more objects, such as tools, equipment, or patients. The navigation system 26 may use various tracking modes individually or in combination. Tracking modes may include: (1) inertial tracking only, (2) inertial tracking and optical tracking only, (3) inertial tracking and electromagnetic tracking only, or (4) inertial tracking with both optical and electromagnetic tracking. Details of these systems and their combinations are set forth below.

[0026] Tracking devices may include those used in conjunction with optical tracking system 63, electromagnetic tracking system 64, and inertial tracking system 65. Optical tracking system 63 includes optical locator 88, and electromagnetic tracking system 64 includes electromagnetic array locator 94. For example, device 68 or another component may be tracked by inertial tracking system 65 alone or in combination with electromagnetic tracking system 64 and optical tracking system 65. Device 68 may include tools such as drills, forceps, catheters, trocars, or other tools operated by user 70. Device 68 may also include implants such as stents, spinal implants, or orthopedic implants. Device 68 may also include components of a system, including but not limited to imaging device 80. It should be further noted that navigation system 26 can be used to navigate any type of device (such as, but not limited to, instruments, implants, stents, or delivery systems), including: guidewires, arthroscopic systems, orthopedic implants, spinal implants, deep brain stimulation (DBS) probes, etc. Furthermore, these instruments can be used to navigate or map any area of ​​the body. The navigation system 26 and various instruments can be used in any appropriate surgery, such as often minimally invasive or open surgery, including cranial surgery.

[0027] Imaging device 80 can be used to acquire preoperative, intraoperative, or postoperative or real-time image data of a subject (such as patient 30). The image data can be used to display images, such as images reconstructed from the image data and / or models altered or reconstructed from the image data. However, it should be understood that imaging can be performed on any suitable subject, and any suitable surgical procedure can be performed relative to the subject. In the example shown, imaging device 80 includes those sold by Medtronic Navigation, Inc., which has a business location in Louisville, Colorado, USA. Imaging apparatus. Imaging apparatus 80 may have a generally annular gantry housing 82 in which an image capture portion is movably disposed. The image capture portion may include an x-ray source or emitting portion, and x-ray receiving portions or image receiving portions are positioned substantially or substantially as far as possible 180 degrees apart from each other and mounted on a rotor relative to a track or guide rail. The image capture portion may be used to rotate 360 ​​degrees during image acquisition. The image capture portion may rotate about a central point or axis, thereby allowing image data of patient 30 to be acquired from multiple directions or in multiple planes. Imaging apparatus 80 may include those disclosed in: U.S. Patent Nos. 7,188,998; 7,108,421; 7,106,825; 7,001,045; and 6,940,941; all of which are incorporated herein by reference in any appropriate portion thereof. In one example, imaging apparatus 80 may utilize flat panel technology with a viewing area of ​​1,720 × 1,024 pixels.

[0028] The precise location of imaging device 80 and / or its portions (such as the image capture portion) relative to any other part of imaging device 80 can be determined. According to various embodiments, imaging device 80 can learn and recall precise coordinates relative to a fixed or selected coordinate system. This allows imaging device 80 to know its location relative to patient 30 or other reference objects. Furthermore, as discussed herein, precise knowledge of the location of the image capture portion can be used in conjunction with a tracking system to determine the location of the image capture portion and image data relative to the tracked subject (such as patient 30).

[0029] The imaging device 80 can also be tracked using the tracking device 62. The tracking device can be an optical, EM, and / or inertial tracking device. According to various embodiments, image data defining the acquired image space of the patient 30 can be inherently or automatically registered relative to the object space. The object or patient space can be the space defined by the patient 30 in the navigation system 26. Automatic registration can be achieved by including a determinable, precise position of the tracking device 62 and / or image capture portion on the imaging device 80. According to various embodiments, as discussed herein, imageable portions, virtual reference points, and other features can also be used to allow automatic or otherwise registration. However, it should be understood that image data of any subject that will define the patient or subject space can be acquired. The patient space is an exemplary subject space. Registration allows for transformation mapping and conversion between the patient space and the image space.

[0030] When the patient moves, the patient 30 can also be tracked using a patient tracker (also referred to as dynamic reference frame 44), which can be tracked using any suitable tracking system (such as those disclosed herein). Alternatively or otherwise, the patient 30 can be fixed within a navigation space defined by navigation system 26 to allow registration. As further discussed herein, registration of the image space with the patient space or subject space allows for navigation of device 68 using image data. When navigating device 68, the positioning of device 68 can be exemplified on the display device 84 of workstation 98 relative to the acquired image data of patient 30 (e.g., superimposed on an image of patient 30). Various tracking systems (such as tracking systems including optical locator 88 or electromagnetic (EM) locator 94) can be used to track device 68.

[0031] The combination of the dynamic reference frame 44 and image registration technology compensates for anatomical distortions caused by subject movement after registration, such as movement of anatomical structures associated with normal physiological processes. The dynamic reference frame 44 may include a dynamic reference frame retainer 56 and a removable tracking device 34. Alternatively, the dynamic reference frame 44 may include a tracking device 34, which may be integrally or separately formed with the DRF retainer 56. Furthermore, the DRF 44 may be provided as a separate component and may be positioned at any suitable location on the anatomical structure. For example, the removable tracking device 34 of the DRF 44 may be attached to the skin of the patient 30 using adhesive. Additionally, the DRF 44 may be positioned near the patient 30's legs, arms, etc. Therefore, the DRF 44 does not require a head frame or any specific base or retaining portion.

[0032] Tracking devices 34, 62, 66, or any tracking device as discussed herein, may include sensors, transmitters, or combinations thereof. Furthermore, tracking devices may be wired or wireless to provide a signal transmitter or receiver within the navigation system. For example, a tracking device may include an electromagnetic coil to sense a field generated by a positioning array or locator 94 or a reflector that reflects signals to be received by the optical locator 88 of the optical tracking system. However, it should be understood that tracking devices 34, 62, 66 may receive signals, transmit signals, or combinations thereof to provide information to the navigation system 26 to determine the positioning of tracking devices 34, 62, 66. The navigation system 26 can then determine the positioning of the tracking devices, and thus the positioning of the devices, to allow navigation relative to the patient and patient space. Reference markers 36 (one of which is illustrated) may be attached to the skin or bone structure of the patient 30. The positioning of reference markers 36 can be used as reference points or registration points for surgery. The tracked device can be used to track the positioning of reference points on the patient 30 and allow the determination of those reference points on the patient. The processor can correlate a reference point on the patient with an image reference point in the image data. The tracking system can track at least one of the tracked device, a dynamic reference frame, or a combination thereof.

[0033] The point selected for registration is a reference point in the image, referred to as an image reference point. The image reference point may be generated by a reference marker 36 or a selected landmark (such as an anatomical landmark). The landmark or reference marker 36 is identifiable in the image data and is identifiable and accessible on the patient 30. Anatomical landmarks may include individual or distinct points on the patient 30 or contours defined by the patient 30 (e.g., three-dimensional contours). The reference marker 36 may be an artificial marker located on the patient 30. Artificial landmarks (such as reference marker 36) may also form part of a dynamic reference system 44, such as those disclosed in U.S. Patent No. 6,381,485, entitled “Registration of Human Anatomy Integrated for Electromagnetic Localization,” issued April 30, 2002, which is incorporated herein by reference. Various reference marker-free systems (including those discussed herein) may not include reference marker 36 or other artificial markers. A reference-mark-free system includes a device or system for defining landmarks or reference points or contours on a patient in physical space. Reference- and mark-free systems may include those that do not include artificial or independent reference marks attached to or positioned on the patient.

[0034] Registration of patient space or physical space with image data or image space may require the correlation or matching of physical or virtual reference points with image reference points. Physical reference points can be reference markers in a substantially unmarked system or landmarks (e.g., anatomical landmarks).

[0035] Registration may require determining the location of a physical reference point in the patient space. The physical reference point may include a reference marker 36. The user 70 may touch the reference marker or device 36 on the patient 30, or a tracking device may be associated with the reference marker 36, allowing the tracking systems 64, 65 to determine the location of the reference marker 36 without a separate tracked device. The physical reference point may also include a contour determined using various techniques (e.g., a 3D physical space contour), as discussed herein.

[0036] Image reference points can also be determined in the image data. User 70 can touch or locate image reference points generated by imaging of reference markers 36 or anatomical landmarks. In addition, various algorithms are generally known to determine the location of image reference points. During image data acquisition, image reference points can be generated in the image data by reference markers 36, specific anatomical landmarks, or the contours of patient 30 (e.g., 3D contours).

[0037] Once the physical and image reference points are identified, image space and physical space can be registered by determining the transformation mapping between image space and physical space. A processor (such as the processor within a workstation 98) determines the registration from patient space to image space. Registration can be performed using commonly known mapping or transformation techniques. Registration allows for navigational surgery using image data.

[0038] More than one tracking system may be used to track device 68 in navigation system 26. According to various embodiments, these may include an EM tracking system with an electromagnetic (EM) locator 94 and / or an optical tracking system with an optical locator 88 and / or an inertial tracking system. Any or all of the tracking systems may be used to track the selected tracking device, as discussed herein. It should be understood that, unless otherwise discussed, the tracking device may be a part capable of being tracked using the selected tracking system. The tracking device does not necessarily refer to the entire component or structure to which the tracking device is attached or associated.

[0039] It should also be understood that imaging device 80 can be different from... The imaging apparatus includes an imaging device, and may additionally or alternatively include a C-arm fluoroscope. Other exemplary imaging apparatus may include fluoroscopes, such as dual-plane fluoroscope systems, ceiling-mounted fluoroscope systems, catheterization lab fluoroscope systems, fixed C-arm fluoroscope systems, isocentric C-arm fluoroscope systems, 3D fluoroscope systems, etc. Other suitable imaging apparatus may also include MRI, CT, ultrasound, etc.

[0040] In various embodiments, the imaging device controller 96 can control the imaging device 80, receive image data generated in the image capture section, and store the images for later use. The controller 96 can also control the rotation of the image capture section of the imaging device 80. It should be understood that the controller 96 does not need to be integrated with the rack housing 82, but can be detached from it. For example, the controller can be part of a navigation system 26, which may include a processing and / or control system, including a processing unit or processing system 102. However, the controller 96 can be integrated with the rack housing 82 and may include a second, separate processor, such as in a portable computer.

[0041] The patient 30 can be secured to the operating table 104. As an example, the operating table 104 can be an Axis system sold by OSI, a subsidiary of Mizuho Ikakogyo Corporation with a business location in Tokyo, Japan, or Orthopedic Systems, a company with a business location in California, USA. Operating table. Patient positioning equipment can be used with the operating table and includes... The clamps or those described in U.S. Patent Application No. 10 / 405,068, filed April 1, 2003, entitled “An Integrated Electromagnetic Navigation And Patient Positioning Device,” are incorporated herein by reference.

[0042] Therefore, the positioning of the patient 30 relative to the imaging device 80 can be determined by the navigation system 26. The tracking device 62 can be used to track and position at least a portion of the imaging device 80 (e.g., the gantry housing 82).

[0043] Accordingly, the positioning of patient 30 relative to imaging device 80 can be determined. Furthermore, due to the precise positioning of the imaging section on the guide rails within housing 82, the substantially inflexible rotor, etc., the position of the imaging section can be determined relative to housing 82. This applies if imaging device 80 is sold by Medtronic Navigation, Inc., which has a business location in Colorado, USA. Imaging apparatus, wherein imaging apparatus 80 may include, for example, an accuracy within 10 micrometers. Precise positioning of the imaging portion is further described below in U.S. Patent Nos. 7,188,998, 7,108,421, 7,106,825, 7,001,045, and 6,940,941, all of which are incorporated herein by reference.

[0044] According to various embodiments, imaging device 80 can generate and / or emit X-rays from an X-ray source, which propagate through patient 30 and are received by an X-ray imaging receiving section. An image capture section generates image data representing the intensity of the received X-rays. Typically, the image capture section may include an image intensifier that first converts the X-rays into visible light and a camera (e.g., a charge-coupled device) that converts the visible light into digital image data. The image capture section may also be a digital device that directly converts the X-rays into digital image data for forming an image, potentially avoiding distortion caused by first converting them into visible light.

[0045] Two-dimensional (2D) and / or three-dimensional (3D) fluorescein image data that can be captured by imaging device 80 can be captured and stored in imaging device controller 96. Multiple image data acquired by imaging device 80 can also be captured and combined to provide a larger view or image of the entire area of ​​patient 30, rather than focusing on only a portion of patient 30. For example, multiple image data of the spine of patient 30 can be appended together to provide a complete view of the spine or a complete set of image data.

[0046] Image data can then be forwarded from the image device controller 96 to a navigation computer and / or processor system 102, which may be part of a controller or workstation 98 having a display 84 and a user interface 106. It should also be understood that image data does not necessarily reside initially in the controller 96, but may also be directly transmitted to the workstation 98. The workstation 98 provides facilities for displaying image data as image 108 on the display 84, saving, digitally manipulating, or printing hard copies of the received image data. The user interface 106 (which may be a keyboard, mouse, stylus, touchscreen, or other suitable device) allows the user 70 to provide input to control the imaging device 80 or adjust image settings on the display 84 via the image device controller 96. The workstation 98 may also instruct the image device controller 96 to adjust the image capture portion of the imaging device 80 to obtain various two-dimensional images along different planes in order to generate representative two-dimensional and three-dimensional image data.

[0047] Continue to refer to Figure 1A The navigation system 26 may also include a tracking system comprising: an inertial tracking system; and / or one or both of an electromagnetic (EM) positioner 94 and / or an optical positioner 88. The tracking system may include a controller 112 and an interface portion 110. The interface portion 110 may be connected to a processor system 102, which may include a processor contained within a computer. The EM tracking system may include those sold by Medtronic Navigation, Inc., which has a business location in Colorado, USA. AXIEM TM A navigation system; or it may be an EM tracking system described in the following patents: U.S. Patent No. 7,751,865, entitled “METHOD AND APPARATUS FOR SURGICAL NAVIGATION,” issued July 6, 2010; U.S. Patent No. 5,913,820, entitled “Position Location System,” issued June 22, 1999; and U.S. Patent No. 5,592,939, entitled “Method and System for Navigating a Catheter Probe,” issued January 14, 1997; all of which are incorporated herein by reference. It should be understood that navigation system 26 may also be or include any suitable tracking system, including those with optical locators. or S7 TM The tracking system, which can be used as an optical locator 88, is sold by Medtronic Navigation, Inc., which has a business location in Colorado, USA. Other tracking systems include acoustic systems, radiation systems, radar systems, etc. The tracking system can be used according to techniques generally known or described in the references combined above. Details are not included herein unless the chosen operation disclosed in the subject matter is clearly explained.

[0048] Wired or physical connections can interconnect the tracking system, imaging device 80, etc. Alternatively, instead of being directly coupled to the processor system 102, various components (such as device 68) can utilize wireless communication channels, such as those disclosed in U.S. Patent No. 6,474,341, entitled "Surgical Communication Power System," issued November 5, 2002, which is incorporated herein by reference. Additionally, tracking devices 62, 66 can generate fields and / or signals sensed by locators 88, 94. Additionally or alternatively, the inertial tracking system may have a tracking device that senses motion to allow determination of the tracking device's position.

[0049] Various parts of the navigation system 26 (such as device 68 and other parts described in detail below) may be equipped with at least one, and typically multiple, tracking devices 66. The apparatus may also include more than one type or form of tracking device 66, such as EM tracking devices and / or optical tracking devices. Tracking devices 66 may also include sensors 72, which may be inertial measurement sensors, also known as inertial monitoring or measurement units (IMUs), disposed on or within device 68. Device 68 may include a grippable or manipulable portion at its proximal end, and the tracking devices may be fixed near the manipulable portion of device 68 or fixed at the other end of device 68.

[0050] Another representative or alternative positioning and tracking system is described in U.S. Patent No. 5,983,126, entitled "Catheter Location System and Method," issued November 9, 1999, which is incorporated herein by reference. Navigation system 26 may be a hybrid system including components from various tracking systems.

[0051] The graphic representation 68i (also known as an icon) can be used to illustrate the position of tool 68 and device 68 relative to image data 108. For example... Figure 1A As shown, the inertial tracking system 65 has a controller 172 for tracking and determining the position of the device 68. As will be described in more detail below, inertial measurements can be performed using selected sensors, such as accelerometers or orientation sensors, or multiple accelerometers or orientation sensors can be used to determine the position of the tool within the patient 30. The inertial tracking system 65 can also be used with optical and EM systems to determine the position of the device and / or the patient. Although shown as a separate component, the controller 172 may be incorporated into and / or communicate with the controller 102 of the workstation 98.

[0052] Now for reference Figure 1B The navigation system 26 is illustrated in a simplified diagram. In this example, the controller communicates with the optical tracking system 63, the electromagnetic tracking system 64, and the inertial tracking system 65. Tracking devices 62 and 66 can be tracked by the optical tracking system 63, the electromagnetic tracking system 64, and the inertial tracking system 65. The DRF 44 can also communicate with the optical tracking system 63 and the electromagnetic tracking system 64. Similarly, the DRF 44 can also be used by the inertial tracking system 65 to locate or register an initial starting point during surgery. The IMU 72 transmits acceleration and gyroscope signals to the inertial tracking system 65, and as will be described in more detail below, the locators 88 and 94 can be used to determine the positioning of the tracking devices 62 and 66. The optical tracking system 63 and the electromagnetic tracking system 64 use the DRF 44 as a reference.

[0053] Now for reference Figure 2 The tool housing 210 of device 68 is illustrated in more detail. Tool housing 210 has a sensor 72 disposed therein. While the discussion herein refers to tool housing 210 and / or tools comprising tool housing 210, the tool does not need to be a surgical instrument. The tool could be a DRF 44, image tracker 62, and / or any other suitable tracking device. Thus, as discussed herein, sensor 72 can be used to sense movement and / or orientation, and the information can be used to determine the path and / or trajectory of any suitable device.

[0054] As described above, sensor 72 may be an inertial measurement unit including a triaxial accelerometer sensor 212, which generates three measured acceleration signals corresponding to the X, Y, and Z axes of the sensor and the positioning of the triaxial accelerometer sensor 212 within the tool housing 210. The three axes of the accelerometer sensor 212 generate accelerometer signals, including an X-axis acceleration signal 212A, a Y-axis acceleration signal 212B, and a Z-axis acceleration signal 212C. Each acceleration axis signal corresponds to acceleration along its respective axis.

[0055] Sensor 72 may also include a triaxial orientation sensor 214. The triaxial orientation sensor 214 generates orientation signals corresponding to orientations about three axes. That is, the triaxial orientation sensor 214 generates an orientation signal about the X-axis, and thus generates an X-axis orientation signal 214A, a Y-axis orientation signal 214B, and a Z-axis orientation signal 214C. In various embodiments, the orientation sensor may be a gyroscope.

[0056] Tool housing 210 may also include tool function actuator 216. Tool function actuator 216 operates the functions of a special tool, such as motor movement of a drill bit or other types of functions. Sensor 72 and tool function actuator 216 are coupled to interface 220. Interface 220 may be a wired interface communicating via wire 174 or a wireless interface communicating via antenna 222. This interface may be part of device tracking system 65 including controller 172 as described above. Sensor 72 can communicate via wired or wireless means.

[0057] The controller 172 of the device tracking system 65 may include a processor 230, which may be any suitable type of processor module and may be microprocessor-based. The processor 230 is designed and / or capable of executing instructions as a program to perform multiple steps to determine the location or trajectory of the device 68, or both. Signals from the sensor 72 are transmitted from interface 220 to interface 232 within the controller 172. Interface 232 may be wired or wireless. In the case of a wireless signal, antenna 234 receives signals from antenna 222. Interface 232 transmits signals to various modules disposed within the controller 172.

[0058] Positioning module 240 is used to determine the position or location of device 68 at the end of each movement segment based on sensor signals. Similarly, trajectory module 242 is used to determine the trajectory of the tool. As will be described in more detail below, positioning module 240 and trajectory module 242 can be used to determine the positioning of the tool at various segments of the travel path.

[0059] Timer 244 can be used to time various functions, including the time difference between the initial and end times of different segments of the travel path. The timer can also be used to determine or time travel segments, such as 1 second, 0.1 seconds, 0.01 seconds, 0.02 seconds, 0.001 seconds, etc. Any appropriate time segment can be measured and / or predetermined.

[0060] Memory 246 may also be included within or associated with controller 172. Memory 246 may be used to store various values, including the initial positioning of the tool, the end positioning of the tool, which may serve as the initial positioning for the next segment, and the velocity at the endpoint of the last segment (as described below).

[0061] Tool function controller 250 may also be included within controller 172. Tool function controller 250 can transmit control signals provided by user 70 from user interface 252. User interface 252 may be, for example, a foot pedal, button, dial, or switch for controlling the function of tool function actuator 216. By providing positioning and trajectory at positioning module 240 and trajectory module 242, various functions of the tool can be provided using the accurate positioning of the tool relative to the patient before the tool is operated.

[0062] Now for reference Figure 3 The diagram illustrates a coordinate system 310 with an origin O and X, Y, and Z axes. It shows the initial positioning P0 and vector D. Point P1 can be calculated using the following formula:

[0063]

[0064] Where P0 is referred to as its coordinates x0, y0, and z0, and vector D These are referred to as Δx, Δy, and Δz. Therefore, P1 will be represented as x1 = x0 + Δx, y1 = y0 + Δy, and z1 = z0 + Δz. The acceleration in each of the three coordinate directions is used to determine the first end position (X, Y, Z). The velocity or trajectory at the end of the segment can also be determined. Figure 3 As shown, the movement toward endpoint P1 can be a single straight line movement along vector D.

[0065] Now for reference Figure 4 This demonstrates more complex forms of motion. For example... Figure 4 As shown, the movement towards endpoint Pn can be along multiple straight line vectors, not along a single straight line vector. Figure 4 In order to understand the final destination, the displacement vectors D1 to Dn at each time point are determined. If the motion is discrete, such as... Figure 4 As shown, the final position is tracked as described here. However, in reality, motion can be a continuous path on a curve.

[0066]

[0067] The D vector is the displacement at each Δt (time). If Δt contracts towards zero (dt), the discrete path advances towards a curved, realistic shape. In this case, the D vector can be described as δD. In a practical sense, the size of each segment must be large enough for the processor to perform acceleration calculations and allow data communication to be completed before the next communication. Therefore, the size of the segment depends on the processor's clock speed and the frequency of communication.

[0068] Now for reference Figure 5 This illustrates the curved path from the initial registration point to the destination. The real-world path can be the path resulting from the free movement of the user's 70-pair tool's hands. However, it should be understood that various systems (such as robotic systems) can have similar characteristics. Figure 4 The movement shown is a real-world movement. To find the destination, at least one of two methods can be used, depending on the implementation. The first method is to find the resulting vector and use it as if it were a single step of movement. The second method is to calculate the target point for each step. The advantage of the first method is that it requires less computation. The advantage of the second method is that it provides real-time tracking of the target point.

[0069] Arithmetic representation:

[0070]

[0071] In this paper, the movement is a vector D, which is the integral (i.e., the sum of movements) over the time interval from the initial time "0" to time "t", as defined by the movement D as a function of time "t" at infinitesimal time intervals dt. t It is the location at time t, and is equal to vector D plus the initial location P0.

[0072] In the second method, arithmetic representation

[0073] According to various implementations, such as EM tracking systems or optical tracking systems, instantaneous positioning (e.g., location and orientation) relative to the origin (e.g., DRF 44) can be determined based on tracking the tracking device. However, using sensor 72, instantaneous positioning may not be known. However, displacement over time can be calculated using the following formula:

[0074] in It is the displacement vector after time t. It is an acceleration vector, and t is time. It is the initial velocity vector, and This is the initial displacement vector. Assume the only known parameter in this equation is... And t, then we can calculate That is, the vector can be determined based on the segment velocity derived from the acceleration and time interval of each segment, and thus the positioning at the end of each segment can be determined. The same orientation signal can be used to determine the trajectory.

[0075] First, the goal is to determine the path from P0 to the target point Pt by finding the displacement vector at each orientation. This is done by starting with the known P0 (registration point, e.g., at DRF 44) and targeting the first... Calculated It is known. Regarding the next... Calculated This will be the first calculation. And the chain continues toward the target point.

[0076] Secondly, the motion begins at P0 (the registration point), which means there is zero velocity at P0. Therefore, for the first... Calculated It is 0, and can be calculated according to the following formula for the next of

[0077]

[0078] These calculations are performed for different segments along the path toward the target point. The acceleration in the formula is a vector that includes the movement path. The term trajectory is used to find the orientation of the device, not the path. Therefore, an orientation system (e.g., a gyroscope (IMU)) is used to determine the trajectory independently of acceleration signals from acceleration sensors.

[0079] Now for reference Figure 6 Based on the above calculations, accelerometers alone are sufficient to find the position (defined path) of the end of each segment. As discussed above, a segment can be a time segment. A typical 3-axis (at least) accelerometer (such as the ICM-20948 sold by TDK) provides X, Y, and Z data signals (which means an acceleration vector including orientation and gyroscope signals) to determine the trajectory at each time point. A simplified flowchart of a method 600 for determining the end-point positioning of the tool is illustrated. In block 610, the initial registration position of the tool is determined. The initial registration position of the tool can be a predetermined position in the area of ​​the operating equipment. Various types of registration systems can use this point as known coordinates to base various movements and positions during surgery. For example, the device can be registered at a fixed reference point, a DRF, or a known position on the patient. The device with sensor 72 can touch a fixed position in the coordinate system to be registered to the navigation system. Sensor 72 can be positioned relative to the “touch” point of the device as a known or predetermined pose. For example, the distal end of the tool can be used for touch registration or close point, and can determine, understand and / or recall the pose of the distal end relative to sensor 72.

[0080] In box 612, the displacement vector based on the accelerometer sensor output is determined. Following the formula above, acceleration and time are used to determine the end positioning or location of the segment. In segments other than the initial segment, trajectory and / or velocity can also be used for positioning or location determination. Based on the acceleration output, the end positioning of the device is determined in box 614. Based on velocity, the time period of the segment, and acceleration in the X, Y, and Z directions, the end positioning of the device is determined at all and / or various movement segments, noting that velocity also has X, Y, and Z components. Various movement segments can have sufficiently large time periods to allow the determination and transmission of calculation results via wired or wireless means. Segments can be selected and / or used to ensure appropriate positioning accuracy, such as millimeter or sub-millimeter accuracy. The communication speed between the two interfaces 220, 232 can be a factor in the segment size. When the communication speed can be faster and the time segment can be smaller. In box 616, it is determined whether movement has continued, and if so, process 600 can be repeated so that further positioning of the device or object during movement can be repeatedly determined. That is, boxes 610, 612, and 614 can be repeated during the procedure. If no further movement occurs in box 616, the process 600 can end in box 617. According to various embodiments, a gyroscope is not required. A gyroscope can be used to improve accuracy and / or determine the instantaneous orientation of device 68 when considering the difference between the trajectory at each point and the trajectory at each movement. A gyroscope can be used to help determine the trajectory, but may only be needed to determine the trajectory once the device stops and / or at instantaneous points. Therefore, an orientation sensor may not be necessary to determine the path trajectory.

[0081] Now for reference Figure 7 As mentioned above, the accelerometer provides the trajectory of the device for each segment of movement. However, it does not provide the instantaneous trajectory of the device at every point. In other words, the orientation trajectory of the tool may not be known solely from the accelerometer signal from sensor 212. Finding the target point comes from the initial positioning and displacement vector (which has a trajectory at each movement). However, identifying the trajectory of the device at the target point is still important once the target point has been reached. The target point can be the desired location for positioning the tool or device used for surgery, and the trajectory at that location may be expected. Such an example could be having a drill bit at a target point on a bone structure and being ready to begin drilling. However, when the tool is held at the same / single point, the direction of drilling needs to be identified by the navigation system.

[0082] exist Figure 7In this process, the tool's trajectory and X, Y, and Z positioning at various sections are determined. In block 710, the tool is brought into contact with the registration point. As mentioned above, the registration point can be a location known from other components of the surgical apparatus. For example, a recess, groove, or reference point in the DRF44. In block 710, the registration for the tool is passed to the controller, and more specifically to the positioning module 240. Figure 2 The positioning module 240 can determine various positioning methods for the start and end of each segment within a section. In block 714, the initial segment positioning and trajectory are determined. The initial segment positioning is the registration point during the process. However, in subsequent segments, the initial segment positioning is the ending segment positioning of the previous positioning. Similarly, the ending trajectory of each segment is the initial trajectory of the subsequent segment. In block 716, the initial segment velocity is determined. At the registration point, the initial velocity is 0. However, the velocity can be determined based on acceleration and time. The initial velocity of a segment can be relative to all three axes (such as the X-axis, Y-axis, and Z-axis).

[0083] In box 718, it is determined whether the accelerometer signal is available. When the accelerometer signal is unavailable, auxiliary techniques for determining positioning and trajectory can be performed. Optical and electromagnetic determination of positioning and trajectory can be performed in a conventional manner. The following... Figure 8 The interface of the auxiliary system is described in further detail. Therefore, if an option is chosen, more than one tracking system can be used to determine the location of the tool.

[0084] In block 718, when the accelerometer signal is available, the three-axis acceleration for each segment is determined in block 722. The three-axis acceleration signal for each segment is provided by the three-axis accelerometer signal of the three-axis accelerometer 212.

[0085] In block 724, orientation sensor 214 generates gyroscope signals. The gyroscope signals are the aforementioned three-axis orientation signals 214A, 214B, and 214C.

[0086] In box 726, timer 244 is used to determine the time interval between the current segment's initial point and the segment's endpoint.

[0087] In block 728, the end position of the segment is determined based on the initial segment positioning as described above. The end position is relative to the initial positioning at the beginning of the current segment and / or relative to the registration positioning. The end position is determined based on triaxial acceleration, segment velocity, and the time period of the segment.

[0088] The tool's positioning can be displayed on the monitor. As mentioned above, acceleration and time can be used to obtain positioning. Similarly, as mentioned above, the velocity at the beginning of a segment, as well as time, can be factored into the determination. Orientation signals can be used to determine the tool's trajectory. Orientation sensors can be used to determine only the orientation of the device, regardless of the path.

[0089] In box 734, if the positioning is greater than a movement threshold, the final segment positioning is stored in memory 246 in box 736. The threshold can be any suitable threshold and may include distance and / or orientation change values. The threshold may be based on the actual and / or expected maximum amount of movement in a single segment. If the positioning difference is greater than the movement threshold, this indicates that the positioning difference exceeds the range of actual or at least expected movement. For example, the tool may be moved a predetermined distance only if it is physically possible or expected to take place over a selected time period. When the positioning is greater than the selected threshold, the positioning value is not used. Thereafter, box 720 uses auxiliary positioning determination techniques to determine the positioning of the device. After box 734, if a new registration point is detected in box 738, box 712 is repeated.

[0090] It should be noted that in box 732, the determined assisted positioning is compared with the positioning difference and trajectory. That is, the system can be used in parallel with non-inertial tracking systems (such as optical or electromagnetic tracking systems) to make the determination as described with respect to box 720. Based on comparison with other techniques, box 734 is executed when the current technique is out of reach.

[0091] Now for reference Figure 8 The text describes a method 800 for positioning using multiple tracking systems. In block 810, an initial position or location is registered. This may be referred to as a registration point. The initial position of an object (such as a device) can be determined using one of the various methods described above. That is, the device can be used to locate various positions, such as by touch, including interaction with a dynamic reference frame 44 or a physical location on the body, including but not limited to the body part itself or a reference mounted to the body part. Once the device or object is in a known initial position, a registration signal can be generated in block 812. The registration signal can be confirmed with the user, such as an auditory signal generated at workstation 98 at speaker 83 or a visual signal at display 84, or both. In this way, the user understands that the initial registration point has been obtained and the procedure can begin.

[0092] In box 814, the device is moved, and acceleration and trajectory are used to determine the position after the movement. Starting from the initial registration point, the velocity is zero (0), and acceleration can be used alone to determine vectors in the X, Y, and Z coordinate systems. The ends and magnitudes of the vectors correspond to the velocity vectors at the endpoints of the segments. As described above, the path from the registration point to the target can be decomposed into multiple segments. At the end of each segment, the position or location is determined using changes in the X, Y, and Z coordinates, as well as the velocity. That is, new vectors are determined for each segment in the X, Y, and Z directions to obtain new position and velocity. However, the initial velocity from the registration point is zero.

[0093] In box 816, the starting location (which may include position and orientation) of the next segment is the end position of the previous segment. However, for effective positioning for the next segment, the end of the previous segment can be selected as a specific distance range within the segment's time period. This specific range can be a threshold and is typically associated with the maximum expected or possible movement during the segment. In box 816, the distance from the end of the previous segment to the new position (or the end of the current segment) is compared to a predetermined distance threshold. This predetermined distance threshold can be referred to as a movement threshold. A predetermined distance is a distance that corresponds to a distance greater than the distance the device is expected to actually move within a predetermined amount of time (the segment's time period). For example, within one millisecond, the selectable device is unlikely to move more than approximately two feet, three feet, or five feet, or any suitable amount of movement. In box 816, when the distance is not greater than the predetermined amount of time, the distance is the selected effective distance within the range of possibilities of the selected threshold. In box 814, the system continues again for the next segment. The next segment uses the previous X, Y, and Z positions, as well as the velocity or end segment position, when determining the trajectory.

[0094] In block 816, when the distance is greater than a predetermined distance, in block 818, the positioning of the end of the segment can be determined from the first auxiliary tracking system. The first auxiliary tracking system can be an optical tracking system or an electromagnetic tracking system for determining positioning. In block 820, the position using the first auxiliary tracking system is compared with the predetermined distance. The positioning from the first auxiliary tracking system is compared with the predetermined distance in a manner similar to that described in block 816. Again, the predetermined distance corresponds to a distance that is practically impossible to move within the time frame since the last segment. Block 820 may also determine whether the first auxiliary tracking system is available.

[0095] When the first auxiliary tracking system is unavailable or the distance traveled is greater than a predetermined distance, in box 822, the second auxiliary tracking system can be used to determine the location. Box 824 determines whether the location from the second auxiliary tracking system is greater than the predetermined distance. When the location is not greater than the predetermined distance, box 826 uses the location from the second auxiliary tracking system. In box 824, when the location from the auxiliary tracking system is greater than the predetermined distance, the system may need to re-register by continuing to box 810.

[0096] In blocks 820 and 818, the first and second auxiliary tracking systems can be optical or electromagnetic. Optical tracking may be unavailable when the field of view is obstructed. Similarly, electromagnetic tracking may be unavailable when metal is near the object or device. However, if the inertial tracking system determines a movement greater than a threshold, one or both of the first or auxiliary tracking systems (if available) can be used to confirm and / or determine the device's location.

[0097] In block 820, when the first positioning or distance is not greater than a predetermined distance (and at least one of the auxiliary systems is available), block 828 uses the positioning from the first auxiliary tracking system as coordinates and uses the velocity at the predetermined positioning to determine the trajectory from the auxiliary tracking system.

[0098] Repeat these boxes until the target is located in box 830. Box 830 is executed after boxes 826 and 828. In box 830, once the target has been located, box 832 ends the process. The surgery can then be performed when the target is reached.

[0099] However, as the system continues to move and has not yet reached the target location in box 830, boxes 814 through 828 can be executed sequentially.

[0100] In this way, the auxiliary tracking system can be used as a backup for the inertial tracking system when unexpected results are obtained that exceed what is actually possible.

[0101] The aforementioned motion-detection navigation has the advantage of navigating in places without a line of sight (optically required) or in places with or without metallic objects (as is the standard for electromagnetic navigation). Motion-detection navigation operates based on an initial starting point and path. However, if path tracking is lost for any reason, the entire navigation may be lost. This can be prevented by controlling the calculations and ensuring that there are no unreasonable steps from one point to another. If there is a large step where the display device has moved an unreasonable amount from one point to another, the control software can invalidate the navigation steps and recalibrate the path using another type of navigation as a backup positioning method, defining a new starting point wherever available.

[0102] Example embodiments are provided to make this disclosure thorough and to fully communicate the scope of this disclosure to those skilled in the art. Numerous specific details, such as examples of particular components, apparatus, and methods, are set forth to provide a thorough understanding of embodiments of this disclosure. It will be apparent to those skilled in the art that specific details are not required, exemplary embodiments may be embodied in many different forms, and should not be construed as limiting the scope of this disclosure. In some exemplary embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.

[0103] The foregoing description of embodiments has been provided for illustrative and descriptive purposes. The foregoing description is not intended to be exhaustive or limiting of the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable and may also be used in chosen embodiments where applicable, even if not specifically shown or described. The same element or feature may be varied in many ways. Such variations are not considered to depart from the invention, and all such modifications are intended to be included within the scope of the invention.

[0104] It should be understood that the various aspects disclosed herein can be combined with combinations different from those specifically presented in the specification and drawings. It should also be understood that, depending on the example, certain actions or events of any of the processes or methods described herein may be performed in a different order, or may be completely added, combined, or omitted (e.g., performing these techniques may not require all the described actions or events). Furthermore, although for clarity some aspects of this disclosure are described as being performed by a single module or unit, it should be understood that the techniques of this disclosure can be performed by combinations of units or modules associated with, for example, a medical device.

[0105] In one or more examples, the described techniques may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functionality may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit (also referred to as a processor). The computer-readable medium may include a non-transitory computer-readable medium, which corresponds to a tangible medium, such as a data storage medium (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and is accessible by a computer).

[0106] Instructions may be executed by one or more processors or processor modules, such as one or more digital signal processors (DSPs), general-purpose microprocessors, application-specific integrated circuits (ASICs), field-programmable arrays (FPGAs), or other equivalent integrated or discrete logic circuits. Therefore, the terms "processor" or "processor module" as used herein may refer to any of the foregoing structures or any other physical structure suitable for implementing the described techniques. Furthermore, these techniques may be fully implemented in one or more circuit or logic elements.

Claims

1. A tracking system, the tracking system comprising: A sensor that generates inertial signals; and A controller that communicates with the sensor determines a first position based on the inertial signal relative to the registration position.

2. The tracking system of claim 1, wherein the sensor is coupled to the object; The object is configured to move from a first location to a second location.

3. The tracking system of claim 1, wherein the inertial signal comprises an accelerometer signal and a gyroscope signal, and the controller determines the trajectory based on at least one of the accelerometer signal or the gyroscope signal.

4. The tracking system of claim 3, wherein the gyroscope signals include orientation signals with respect to the X-axis, Y-axis and Z-axis.

5. The tracking system according to claim 1, wherein the accelerometer signal includes an X-axis acceleration signal, a Y-axis acceleration signal, and a Z-axis acceleration signal.

6. The tracking system of claim 1, wherein the sensor communicates with the controller via at least one of wired or wireless means.

7. The tracking system of claim 1, wherein the controller determines a plurality of locations, each of the plurality of locations being based on a previous location other than the registration location.

8. The tracking system of claim 7, wherein when one of the first locations is greater than a distance threshold, the controller uses auxiliary location from the auxiliary tracking system to compare the first location with the distance threshold.

9. The tracking system according to claim 8, wherein the auxiliary tracking system comprises an electromagnetic tracking system.

10. The tracking system of claim 8, wherein the auxiliary tracking system comprises an optical tracking system.

11. The tracking system of claim 1, wherein the controller includes a processor; The processor is configured to execute instructions to determine the sensor's pose after a segment based on at least the inertial signal relative to the sensor's initial pose.

12. A method, the method comprising: Determine the registration and positioning for the target object; Based on the movement of the object, an accelerometer signal is generated at a sensor coupled to the object; The accelerometer signal is transmitted from the sensor to the controller; as well as The controller determines the first position based on the accelerometer signal and the registration positioning.

13. The method according to claim 12, further comprising: A gyroscope signal is generated at the sensor and transmitted to the controller; as well as The trajectory of the sensor is determined based on the gyroscope signal.

14. The method of claim 13, wherein generating the gyroscope signal comprises: The gyroscope signal is generated, which includes orientation signals about the X, Y, and Z axes.

15. The method of claim 12, wherein generating the accelerometer signal comprises: Generate X-axis acceleration signals, Y-axis acceleration signals, and Z-axis acceleration signals.

16. The method according to claim 12, further comprising: Multiple locations of the object are determined after the registration and positioning, each of the multiple locations being based on a previous location and trajectory, the previous location being based on the accelerometer signal.

17. The method according to claim 16, further comprising: An auxiliary tracking system is used to generate auxiliary positioning signals.

18. The method according to claim 17, further comprising: The first location is compared with a distance threshold. When the first location is greater than the distance threshold, the location is determined based on the auxiliary location signal.

19. The method of claim 18, wherein generating the auxiliary positioning signal comprises: The auxiliary positioning signal is generated using at least one of an electromagnetic tracking system or an optical tracking system.

20. The method of claim 14, further comprising: The trajectory at the first positioning point is determined based at least on the generated gyroscope signal.

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