Surgical Navigation System And Method

Abstract

The present disclosure relates to a surgical navigation system for the alignment of a surgical instrument and methods for its use, wherein the surgical navigation system may comprise a head-mounted display comprising a lens. The surgical navigation system may further comprise tracking unit, herein the tracking unit may be configured to track a patient tracker and/or a surgical instrument. Patient data may be registered to the patient tracker. The surgical instrument may define an instrument axis. The surgical navigation system may be configured to plan one or more trajectories based on the patient data. The head-mounted display may be configured to display augmented reality visualization, including an augmented reality position alignment visualization and/or an augmented reality angular alignment visualization related to the surgical instrument on the lens of the head-mounted display.

What is claimed is: 
     
         1 . A head-mounted display for use with surgical navigation system including a patient tracker and a surgical instrument tracker, the surgical navigation system configured to plan a target trajectory axis based on patient data and for the alignment of an instrument axis that is at least partially defined by a tip of a surgical instrument with the target trajectory axis, said head-mounted display comprising:
 a lens; and   wherein the head-mounted display is further configured to display an augmented reality angular alignment visualization comprising a deviation angle which represent the angle between a first angular vector representative of the instrument axis and a second angular vector representative of the target trajectory axis.   
     
     
         2 . The system of  claim 1 , wherein the deviation angle is configured to be scaled to allow the user to see small deviations in the angle between the first angular vector and the second angular vector. 
     
     
         3 . The system of  claim 1 , wherein the augmented reality angular alignment visualization comprises a decomposition of the angle between a first angular vector representative of the instrument axis and a second angular vector representative of the target trajectory axis of the angle into two deviation angles. 
     
     
         4 . A method of aligning a surgical instrument using a surgical navigation system, the surgical navigation system including a tracking unit configured to track the position of a head-mounted display, a patient tracker, and a surgical instrument tracker coupled to a surgical instrument having a tip and defines an instrument axis, and wherein the surgical navigation system is configured to plan a target trajectory axis based on patient data registered to the patient tracker, the method comprising the steps of:
 displaying on the head-mounted display an augmented reality angular alignment visualization comprising a deviation angle which shows the angle between a first angular vector representative of the surgical instrument axis and a second angular vector representative of the target trajectory axis; and   continuously updating the augmented reality angular alignment visualization displayed on the head-mounted display based on the tracking unit to indicate the location of the surgical instrument axis relative to the target trajectory axis from the perspectives of the head-mounted display.   
     
     
         5 . The method according to  claim 4 , wherein the target trajectory axis defined by a line connecting a target object and an entry point. 
     
     
         6 . The method according to  claim 4 , further comprising displaying an augmented reality visualization of an instrument axis of the surgical instrument on the head-mounted display. 
     
     
         7 . The method according to  claim 4 , further comprising using different colors for displaying the augmented reality angular alignment visualization so that the user can distinguish the respective alignment visualization; and
 highlighting the augmented reality angular alignment visualization to the user based on a distance of the surgical instrument to the target trajectory axis.   
     
     
         8 . The method according to  claim 4 , wherein a distance between the surgical instrument and the target trajectory axis is computed based on a distance of the tip of the surgical instrument to at least one selected from the group consisting of a segment connecting a target object and an entry point of the target trajectory axis, a line connecting the target object and the entry point of the target trajectory axis, the target object, and the entry point of the trajectory. 
     
     
         9 . The method according to  claim 7 , wherein the highlighting of the target trajectory axis comprises hiding all additional trajectories from the user except the one with the minimum distance. 
     
     
         10 . The method according to  claim 7 , showing all additional trajectories except the one with the minimum distance with increased transparency. 
     
     
         11 . The method according to  claim 4 , wherein a decomposition of the two deviation angles is relative to two eigenvectors derived from:
 two of the three primary patient axes with the highest angle to the target trajectory axis, and   a line of sight axis being projected onto a plane perpendicular to the target trajectory axis and attached to the closest point on the target trajectory axis from the tip of the surgical instrument, and a perpendicular vector in the same plane to the projected line of sight axis.   
     
     
         12 . The method according to  claim 7 , wherein the visualization of the deviation angle comprises:
 a position correct augmented reality visualization of the instrument axis, the target trajectory axis and an arc connecting proximal ends of both the instrument axis and the target trajectory axis.   
     
     
         13 . The method according to  claim 7 , wherein the visualization of the deviation angle comprises:
 an axonometry of a position correct augmented reality visualization of the instrument axis.   
     
     
         14 . The method according to  claim 6 , further comprising displaying a first augmented reality textual label for describing a distance from the tip of the surgical instrument to the target trajectory axis and a second augmented reality textual label for describing the deviation angle in degrees between the instrument axis and the target trajectory axis positioned in or near the angular visualization. 
     
     
         15 . The method according to  claim 4 , further comprising displaying an augmented reality visualization of a target object to be placed or removed at a target point of the target trajectory axis wherein the augmented reality visualization of the target object is positioned at the target position or at the current position of the surgical instrument. 
     
     
         16 . The method according to  claim 4 , further comprising the step of an augmented reality visualization of a target object to be placed or removed at a target point of the target trajectory axis. 
     
     
         17 . The method according to  claim 5 , wherein different colors for the augmented reality visualizations are selected from a base color of a trajectory by equidistant placing of alternate colors in a chromaticity space around a white point and selecting their dominant wavelength by extrapolation; and/or
 wherein the colors are selected from high-luminance complementary colors selected from the group comprising yellow, pink, green and cyan.   
     
     
         18 . The method according to  claim 4 , further comprising the step of displaying an augmented reality visualization of a slice of patient image data comprising the steps of:
 selecting an augmented reality visualization location chosen by the surgeon to be one of a fixed frame in space, a floating frame following head movement, an in-place at the position of the patient image data slice, or an offset from the patient position by a user defined fixed spatial vector;   a color mapping from patient image data color information to augmented reality visualization color information including alpha transparency target ranges; and   a user interaction by which the user can use any of a voice, mouse, keyboard, gaze, or surgical instruments to choose and reposition the augmented reality visualization location and select the slice of patient image data.   
     
     
         19 . The method according to  claim 4 , further comprising displaying a region of interest indicator, said region of interest indicator comprising:
 an augmented reality textual labels shown in the vicinity of the region of interests or   an augmented reality boundary visualizations demarcating the region of interests, and   a color mapping method which highlights to the user the augmented reality textual labels and augmented reality boundary visualization based on a distance of the navigated instrument to the region of interest.   
     
     
         20 . A surgical navigation system, a patient tracker trackable by the surgical navigation system, and a surgical instrument trackable by the surgical navigation system, said surgical instrument guidance system comprising:
 a display;   a controller configured to display an augmented reality angular alignment visualization on the display comprising a deviation angle which represent the angle between a first angular vector representative of an instrument axis and a second angular vector representative of a target trajectory axis.