Method and system for registration verification

A system for verifying registration of a model of a body part with the internal body part in a reference coordinate system, said model and said internal body part previously registered in said reference coordinate system, said body part being at least partially unseen directly by a user, the system comprising:

• a head mounted display to be donned by said user;
• a head mounted display tracking module for continuously determining information relating to the position and orientation of said head mounted display in said reference coordinate system;
• and
• a processor, coupled with said head mounted display tracking module, determining the position and orientation of said head mounted display in said reference coordinate system and determining the display location of at least one virtual marker according to the position of a respective at least one reference point relative to said head mounted display, said reference point being visible to said user, the position of said at least one reference point in said reference coordinate system is predetermined, said processor rendering said at least one virtual marker to be displayed on said head mounted display,
• wherein, when said model and said body part are effectively registered, said at least one reference point and corresponding virtual marker appear on said head mounted display visually in alignment,
• wherein, when said model and said body part effectively fall out of registration, said at least one reference point and corresponding virtual marker appear on said head mounted display visually out of alignment.

A method for verifying registration of a model of an internal body part with the internal body part in a reference coordinate system, said model and said internal body part previously registered in said reference coordinate system, said internal body part being at least partially unseen directly by a user, the method comprising the procedures of:

• acquiring an image of at least one reference point from a known position and orientation in said reference coordinate system;
• identifying the at least one reference point in said acquired image and determining the image location of said at least one reference point, said at least one reference point being directly visible to said user, the position of said at least one reference point in said reference coordinate system is predetermined;
• determining the expected image location of at least one reference point according to the position of said at least one reference point and said position and orientation from which said image was acquired in the reference coordinate system;
• determining the congruence between said predicted and determined image location of said at least one reference point,
• wherein when said model and said internal body part are registered, said predicted and determined image locations are congruent with each other,
• wherein when said model and said internal body part fall out of registration, said predicted and determined image locations are not congruent with each other.