Method of medical calibration

Abstract

The present disclosure relates to a method of medical calibration, including the method steps of: capturing an image representation of a medical marker and of a medical instrument connected therewith; determining a spatial pose of the medical marker on the basis of the image representation; determining a first position of a tracking point of the medical instrument on the basis of the determined spatial pose and on the basis of information relating to a spatial pose relationship between medical marker and tracking point, and determining a second position of the tracking point on the basis of the captured image representation; determining a deviation between the first position and the second position; adjusting the information relating to the spatial pose relationship between medical marker and tracking point on the basis of the determined deviation.

1 . A method of medical calibration, comprising the method steps of:
 capturing an image representation of a medical marker and of a medical instrument connected therewith;   determining a spatial pose of the medical marker on the basis of the image representation;   determining a first position of a tracking point of the medical instrument on the basis of the determined spatial pose and on the basis of information relating to a spatial pose relationship between medical marker and tracking point, and determining a second position of the tracking point on the basis of the captured image representation;   determining a deviation between the first position and the second position; and   adjusting the information relating to the spatial pose relationship between medical marker and tracking point on the basis of the determined deviation.   
     
     
         2 . The method according to  claim 1 , further comprising the method steps of:
 capturing a multiplicity of image representations of the medical marker and of the medical instrument connected therewith;   determining, for each of the captured image representations, the first position and the second position of the tracking point in the captured image representation and a deviation between the first position and the second position; and   adjusting the information relating to the spatial pose relationship between medical marker and tracking point on the basis of the multiplicity of determined deviations.   
     
     
         3 . The method according to  claim 1 , wherein calibrated information relating to the spatial pose relationship between medical marker and tracking point is available if a deviation between the first position and the second position is determined as being below a predetermined threshold value. 
     
     
         4 . The method according to  claim 3 , further comprising a continuous determination of first positions of the tracking point on the basis of continuously captured image representations of the medical marker and of the medical instrument connected therewith and on the basis of the calibrated information relating to the spatial pose relationship between medical marker and tracking point. 
     
     
         5 . The method according to  claim 1 , further comprising:
 intermittently determining second positions of the tracking point in a selection of continuously captured image representations of the medical marker and of the medical instrument connected therewith;   determining deviations between the first position and the second position of the tracking point in the selection of continuously captured image representations; and   adjusting the information relating to the spatial pose relationship between medical marker and tracking point if one of the determined deviations exceeds a predetermined limit value.   
     
     
         6 . The method according to  claim 1 , wherein the medical marker has a geometry and the spatial pose of the medical marker is determined on the basis of the captured image representation of the medical marker and on the basis of information relating to the geometry of the medical marker. 
     
     
         7 . The method according to  claim 6 , wherein the image representation of the medical marker contains image representations of at least three marker elements, the information relating to the geometry of the medical marker including information relating to the relative spatial pose of the marker elements with respect to one another and determining the spatial pose of the medical marker including the determination of the spatial poses of the marker elements. 
     
     
         8 . The method according to  claim 7 , wherein the information relating to the spatial pose relationship between medical marker and tracking point defines a relative spatial pose of the tracking point with respect to the marker elements and/or with respect to a target point that has a fixed spatial relationship with respect to the marker elements. 
     
     
         9 . The method according to  claim 6 , wherein the information relating to the geometry of the medical marker is predetermined. 
     
     
         10 . The method according to  claim 6 , further comprising:
 capturing a first image representation of the medical marker in a first perspective;   capturing a second image representation of the medical marker in a second perspective; and   determining the information relating to the geometry of the medical marker on the basis of the first image representation and the second image representation.   
     
     
         11 . The method according to  claim 1 , wherein the second position of the tracking point is determined by means of image recognition and/or a machine learning algorithm in the captured image representation. 
     
     
         12 . The method according to  claim 1 , wherein the image representations of the medical marker and of the medical instrument connected therewith are captured by means of a monocular system. 
     
     
         13 . The method according to  claim 1 , wherein at least one image representation of the medical marker and of the medical instrument connected therewith is captured by means of a first camera and a second camera, or image representations of the medical marker and of the medical instrument connected therewith are captured immediately before and after a defined robotic actuation of a capturing camera or of the medical marker and of the medical instrument connected therewith. 
     
     
         14 . A medical calibration system comprising:
 an imaging sensor;   a medical marker;   a medical instrument;   a control unit connected to the imaging sensor; and   a storage unit connected to the control unit and comprising commands which, upon execution by the control unit, cause the latter to carry out the method according to  claim 1 .   
     
     
         15 . A computer program comprising commands which, upon execution by the control unit of a system according to  claim 14 , cause the system according to  claim 14  to carry out the method according to  claim 1 .