Patent Publication Number: US-2022218419-A1

Title: Medical instrument with fiducial markers

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a Continuation-in-Part, and claims the benefit of, U.S. patent application Ser. No. 17/148,522 filed on Jan. 13, 2021, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     Current conventional systems have limitations with regard to two-dimensional (2D) and three-dimensional (3D) images in surgical settings. Surgical planning and surgical navigation are necessary for every medical procedure. A surgeon and their team must have a plan for a case before entering an operating room, not just as a matter of good practice but to minimize malpractice liabilities and to enhance patient outcomes. Surgical planning is often conducted based on medical images including DICOM scans (MRI, CT, etc.), requiring the surgeon to flip through numerous views/slices, and utilizing this information to imagine a 3D model of the patient so that the procedure may be planned. Accordingly, in such a scenario, the best course of action is often a surgeon&#39;s judgment call based on the data that they are provided. 
     SUMMARY 
     Conventional systems are deficient with respect to tracking fiducial markers disposed on physical instruments. Often, such conventional systems are limited in their ability to generate, render and accurately apply virtual interact ions in an augmented reality environment based on physical orientations and positions resulting from movement and manipulation of physical instruments. 
     Various embodiments of a physical instrument described herein provide for significant improvements and advantages over such conventional systems. According to one or more embodiments, the physical instrument includes a main tubular body with a first terminal portion and a second terminal portion. It is understood that various embodiments may have multiple terminal portions, such as more than two terminal portions. The physical instrument further comprises a code platform proximate to the first terminal portion of the main tubular body. The code platform includes a plurality of different codes. The physical instrument also includes at least one of: (i) a flat tip at the second terminal portion and (ii) a passage internal to the main tubular body and extending from the first terminal portion to the second terminal portion. It is understood that, in some embodiments, a physical instrument may be a medical surgical instrument. It is further understood that, instead of a flat tip, some embodiments may have a tip that is of a rounded shape, such as a half-sphere. 
     One or more fiducial markers (or codes) disposed on the code platform may be composed of a non-reflective material that absorbs light (i.e. visible light). According to various embodiments, the one or more fiducial markers may be composed of a material(s) that provides each fiducial marker with a visual contrast against the visual appearance of at least a portion the of the physical instrument. As such, various embodiments of the physical instrument may be tracked by a visible light camera, thereby alleviating a requirement of utilizing a infrared tracking system typically found in conventional systems. 
     It is understood that the various embodiments of the physical instrument may be utilized in conjunction with an augmented reality (AR) display system. For example, the AR display system may one or more embodiments of a Registration Engine as described in U.S. patent application Ser. No. 17/148,522 filed on Jan. 13, 2021. 
     According to various embodiments, the physical instrument may be an anatomical landmark registration localizer (hereinafter “localizer”). The localizer includes a plurality of fiducial markers that can be tracked via an AR display system. According to various embodiments, an end-user wearing an AR display headset may manipulate the localizer by hand while the AR display system integrates a visualization of the localizer within an interactive AR environment displayed and viewed via the AR display headset. 
     The end-user may place the tip of the localizer at one or more locations of an anatomical region of an individual&#39;s physical body, whereby each respective location may be a landmark the end-user desires to be registered by the AR display system. To register a landmark within the anatomical region, the AR display system determines a physical position and orientation of the localizer with respect to a fixed reference position of a three-dimensional (3D) unified coordinate system. 
     Upon receipt of the indication from the end-user that the flat tip is in contact with a desired landmark, the AR display system captures the coordinates of one or more fiducial markers disposed on the physical instrument. The AR display system further calculates one or more spatial transformations and executes position mapping based on the fiducial marker coordinates in order to calculate coordinates that represent a position of the desired landmarks on the individual&#39;s body within the 3D unified coordinate system. 
     In some embodiments, the physical instrument may be a sheath. A trajectory for a surgical instrument or tool may be planned via the AR display system. For example, the AR display system may generate and render a trajectory line for display by the AR display headset. The trajectory may be based on a target point and an entry point, whereby both the target point and the entry may both correspond to different 3D medical model data concurrently displayed by the AR display system. The target point may correspond to 3D medical model data that represents an internal anatomical region and the entry point may correspond to 3D medical model data for an outer anatomical region, such as a particular location on a skin surface. 
     The AR display system may generate and render an AR display of the trajectory via the AR display headset. An end-user wearing the AR display headset may manipulate the sheath by hand while the AR display system integrates a visualization of both the rendered trajectory and the sheath within an interactive AR environment displayed and viewed via the AR display headset. The AR display system determines a physical position and orientation of the sheath with respect to a fixed reference position of a three-dimensional (3D) unified coordinate system. The target and entry points for a trajectory are based on coordinates selected with the localizer whereby each of the target and entry point is a difference coordinate in the 3D unified coordinate system. 
     The AR display system captures coordinates of one or more fiducial markers disposed on the sheath. The AR display system further calculates one or more spatial transformations and executes position mapping based on the fiducial marker coordinates in order to calculate and verify whether a portion of the sheath has a current physical orientation that is in alignment with the respective coordinates that occur along the rendered trajectory. For example, the AR display system may capture coordinates of the one or more fiducial markers to determine whether a physical orientation of a main tubular body of the sheath is aligned with the rendered trajectory. The main tubular body further includes an internal passage through which a physical surgical instrument or tool may be inserted into and through the main tubular body such that the physical surgical instrument or tool exits the main tubular body along the rendered trajectory. 
     According to various embodiments, the code platform of the physical instrument may include a plurality of codes. Each respective code may be disposed on a top surface of the code platform and be composed of a non-reflective material that absorbs light. For example, the code platform may include a first hamming code and a second hamming code. The first hamming code may be different than the second hamming code. An error tolerance exists between the first and the second hamming codes. 
     In various embodiments, the first hamming code is situated within a first fiducial marker region of the code platform and the second hamming code is situated within a second fiducial marker region of the code platform. 
     Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for illustration only and are not intended to limit the scope of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will become better understood from the detailed description and the drawings, wherein: 
         FIG. 1  is a diagram illustrating a type of perspective view of an exemplary embodiment. 
         FIG. 2  is a diagram illustrating a type of perspective view of an exemplary embodiment. 
         FIG. 3  is a diagram illustrating a type of perspective view of an exemplary embodiment. 
         FIG. 4  is a diagram illustrating a type of perspective view of an exemplary embodiment. 
         FIG. 5  is a diagram illustrating a type of perspective view of an exemplary embodiment. 
         FIG. 6  is a diagram illustrating a type of perspective view of an exemplary embodiment. 
         FIG. 7  is a diagram illustrating a type of perspective view of an exemplary embodiment. 
         FIG. 8  is a diagram illustrating a type of perspective view of an exemplary embodiment. 
         FIG. 9  is a diagram illustrating a type of perspective view of an exemplary embodiment. 
         FIG. 10  is a diagram illustrating a type of perspective view of an exemplary embodiment. 
         FIG. 11  is a diagram illustrating a type of perspective view of an exemplary embodiment. 
         FIG. 12  is a diagram illustrating a type of perspective view of an exemplary embodiment. 
         FIG. 13  is a diagram illustrating a type of perspective view of an exemplary embodiment. 
         FIG. 14  is a diagram illustrating a type of perspective view of an exemplary embodiment. 
         FIG. 15  is a diagram illustrating a type of perspective view of an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In this specification, reference is made in detail to specific embodiments of the invention. Some of the embodiments or their aspects are illustrated in the drawings. 
     For clarity in explanation, the invention has been described with reference to specific embodiments, however it should be understood that the invention is not limited to the described embodiments. On the contrary, the invention covers alternatives, modifications, and equivalents as may be included within its scope as defined by any patent claims. The following embodiments of the invention are set forth without any loss of generality to, and without imposing limitations on, the claimed invention. In the following description, specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be practiced without some or all of these specific details. In addition, well known features may not have been described in detail to avoid unnecessarily obscuring the invention. 
     As shown in  FIG. 1 , an embodiment of a localizer (or a sheath as described herein) may have a main tubular body  100  and a code platform  102 . The code platform  102  may include one or more codes  104 ,  106 . In some embodiments, the codes  104 ,  106  may be different hamming codes. A padding  108  may further be disposed on the code platform  102 . For example, the padding  108  may border one or more edges of each of the codes  104 ,  106  on the code platform  102 . The one or more codes  104 ,  106  may be composed of a non-reflective material that absorbs light. As such, various embodiments of the physical instrument may be tracked by a visible light camera, thereby alleviate the requirement of utilizing an infrared tracking system typically found in conventional systems. In some embodiments, the physical instrument may be composed of a plastic nylon material, stainless steel or aluminum. In some embodiments, the physical instrument may be a medical instrument with a composition that includes a sterilized material, such as a material sterilized via gamma-sterilization or auto-clave. 
     As shown in  FIG. 2 , the code platform  102  may have a top surface  114 . The top surface  114  may include a first fiducial marker region  116  and a second fiducial marker region  118 . It is understood that, in various embodiments, the first and second fiducial marker regions  116 ,  118  may be the one or more codes  104 ,  106 —respectively. A portion of the code platform  102  that includes the first fiducial marker region  116  may be disposed on the localizer such that region  116  is parallel to the main tubular body  100 . The main tubular body  100  may have a first terminal portion  110  and a second terminal portion  112 . The code platform  102  may be connected to the first terminal portion  110 . The second fiducial marker region  118  may be angled towards the first terminal portion  110  such that a degree amount  150  that is greater than  180  exists between the respective fiducial marker regions  116 ,  118 .In various embodiments, the tubular body  100  may have one or more measurement markings representing distance from the tip. 
     As shown in  FIG. 3 , a bottom surface  120  of the code platform  102  may be connected to the first terminal portion  110 . As shown in  FIG. 4 , the second terminal portion  112  may include a tapered tubular segment  122 . The tapered tubular segment  122  may further include a flat tip  124  of the main tubular body  100 . 
     As shown in  FIG. 5 , the main tubular body  100  may include a tubular segment  126  and one or more tapered tubular segments  122 ,  122 - 1 ,  122 - 2 . It is understood that all of the tapered tubular segments  122 ,  122 - 1 ,  122 - 2  illustrated in  FIG. 5  may be interpreted as each being a respective part of a single tapered tubular segment that is adjacent to the tubular segment  126 . The tapered tubular segment  122  may have a first segment portion with a first diameter that is larger than a second diameter at a second segment portion, whereby the second diameter is substantially similar to a diameter of the flat tip  124 . 
       FIGS. 6-7  each illustrate a hand position for holding an embodiment of the localizer. 
     It is understood that while various portions and/or segments of the physical instrument are described herein as having a tubular shape(s). Various embodiments of the physical instrument are not restricted or limited to only having tubular portions and/or tubular segments. 
     As shown in  FIG. 8 , an embodiment of the localizer may include a main tubular body  200 . The main tubular body  200  may have a first terminal portion  210  and a second terminal portion  212 . The second terminal portion  212  may and in a flat tip  224 . A code platform  202  may be proximate to the first terminal portion  210 . The code platform  202  may have a top surface that includes one or more codes  204 ,  206  and a padding  208  that surrounds and borders the respective edges of the codes  204 ,  206 . 
     The one or more codes  204 ,  206  may be angled away from the main tubular body  200 . For example, each code  204 ,  206  may be a respective fiducial marker region disposed on the top surface  214  of the code platform  202 . As shown in  FIG. 8 , wherein the localizer is oriented in a vertical position with the code platform  202  above the flat tip  224 , the code platform  202  may be shaped according to a “V” formation such that a central portion of the code platform  202  is attached to the first terminal portion  210  and a degree amount  250  that is less than 180° exists between the fiducial marker regions on the top surface  214 . In other embodiments, the degree amount  250  may be larger than 180°, to result in an “upside down V” formation. 
     As shown in  FIG. 9 , the code platform  202  may have a bottom surface  220  that is attached to the first terminal portion  210 .  FIGS. 10-11  each illustrate a hand position for holding an embodiment of the localizer.  FIG. 10  provides a perspective view directly above the top surface  214  of the code platform  202  resulting from the hand position for holding the localizer.  FIG. 11  provides a perspective side view of the localizer resulting from the hand position for holding the localizer. 
     As shown in  FIG. 12 , an embodiment of a sheath may include a main tubular body  300 . The main tubular body  300  may include a first terminal portion  310  and a second terminal portion  312 . An arm  350  may extend perpendicularly away from the main tubular body  300 . The arm  350  may be attached to the main tubular body  300  proximate to the first terminal portion  310 . The arm  350  may be connected to a code platform  302 . The code platform  302  may have a top surface  314  upon which one or more codes  304 ,  306  are disposed. The top surface  314  may have a padding  308  that surrounds the respective codes  304 ,  306  and borders the respective codes  304 ,  306 . The one or more codes  304 ,  306  may be angled downwards and towards the direction of the second terminal portion  312 . The main tubular body  300  may include a first opening of internal passage  360  that extends from an edge of the first terminal portion  310  to an edge of the second terminal portion  312 . 
     As shown in  FIG. 13 , a second opening of the internal passage  360 - 1  may be included at the edge of the second terminal portion  312 . As the codes  304 ,  306  on the top surface  314  are angled away from each other, a degree amount  370  less than 180° exists between a first portion of the bottom surface  320  and a second portion of the bottom surface  320 . In other embodiments, the degree amount  250  may be larger than 180°, whereby the code platform  302  comprises a “V” formation. 
     As shown in  FIG. 14 , the arm  350  connects the code platform  302  to the main tubular body  300 . An internal passage extends throughout and within the main tubular body  300 . The internal passage is accessible via openings  360 ,  360 - 1  at terminal portions of the main tubular body  300 . The main tubular body  300  further includes a tapered tubular segment  322  and a tubular segment  326 . The tapered tubular segment  322  includes the flat tip  324 . A first diameter  328  of the tapered tubular segment  322  may be equal to a diameter of a portion of the first tubular segment  326 . A second diameter  330  of the tapered tubular segment  322  may be a diameter of the flat tip itself  324 . A particular passage opening  360 - 1  may be accessible at the flat tip  324 . 
       FIG. 15  provides a perspective side view of a hand position for holding the sheath. 
     In the foregoing disclosure, implementations of the disclosure have been described with reference to specific example implementations thereof. It will be evident that various modifications may be made thereto without departing from the broader spirit and scope of implementations of the disclosure as set forth in the following claims. The disclosure and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.