Method and system for trackerless image guided soft tissue surgery and applications of same

A method for performing trackerless image guided soft tissue surgery on a living subject, comprising:

• (a) performing at least one image-to-physical registration to the living subject, comprising:
• (1) performing a pre-operative registration to an organ of the living subject wherein the organ is formed by the soft tissue, comprising:
• generating a first three-dimensional textured point cloud (TPC) for a surface of the living subject covering the organ by placing a plurality of first markings on a surface of the living subject;
• scanning at least one field of view (FOV) image of the surface of the living subject with the first markings;
• constructing the three-dimensional TPC based on the at least one FOV image using principles of computer vision;
• and
• registering the first three-dimensional TPC to a magnetic resonance (MR) model of the organ to generate a fused three-dimensional TPC-to-MR display visibly relating the FOV of the surface of the living subject as represented by the TPC to the MR image volume used for surgery planning;
• performing an entry-into-body plan on the surface using the fused three-dimensional TPC-to-MR display, wherein the fused three-dimensional TPC-to-MR display is provided as an initial MR-to-patient alignment;
• and
• (2) performing an intra-operative cortical surface registration to the MR model for a MR-to-cortical surface alignment, comprising:
• opening the surface based on the craniotomy plan to expose a cortical surface of the organ;
• capturing at least one FOV image of the cortical surface of the organ with a plurality of second markings, wherein the second markings are visible in the at least one FOC image of the cortical surface of the organ;
• generating a second three-dimensional TPC for the cortical surface of the organ based on the at least one FOV image of the cortical surface of the organ;
• and
• performing the MR-to-cortical surface alignment by registering the second three-dimensional TPC to the MR model to generate an intra-operatively fused three-dimensional TPC-to-MR display visibly relating the FOV of the cortical surface of the organ for absolute deformation measurement;
• (b) performing the absolute deformation measurement of the organ of the living subject based on the second markings maintaining a fixed reference to the living subject subsequent to the at least one image-to-physical registration;
• (c) performing shift correction to the organ using the absolute deformation measurements;
• and
• (d) adjusting an image guidance system (IGS) based on the shift correction for performing operation to the organ,
• wherein the method is performed without a separate optical tracking device.