System and methods for updating patient registration during surface trace acquisition
A surgical navigation system and method for identifying positions on a patient, including a processor, and a tracking system for tracking a pointer tool. The processor is programmed to initialize a surface trace acquisition, continuously record the positions of the pointer tool during the surface, conduct trace acquisition, combine the positions recorded during the surface trace acquisition into a surface trace, receive a patient image of the patient, extract a surface from the patient image, compute a registration transform between the surface traces and the surface for patient registration, segment the patient image into a regions where each region contains an anatomical landmark, determine a spatial distribution of surface traces among the regions; determine whether the spatial distribution in relation to each region minimizes deviance below a threshold, and if the determination is exceeding the threshold, provide information relating to such region.
1. A method of dynamically updating a registration real time during a surface trace acquisition, comprising:
selecting a registration technique from a plurality of registration techniques, wherein the plurality of registration techniques comprises a touchpoint fiducial registration technique and a surface trace registration technique;
if the surface trace registration technique is selected,
collecting initial feature points;
performing a surface extraction;
collecting initial points;
computing an initial registration by applying a non-linear template-matching technique, thereby providing an initial registration;
updating registration by iteratively collecting points; and
registering all points, thereby providing an updated registration;
if the touchpoint fiducial registration technique is selected,
touching and registering a plurality of fiducial points and
if not sufficiently accurate, repeating touching and registering a plurality of fiducial points, and
if further accuracy is desired, performing a surface extraction and reviewing the registration; and
if the registration is determined accurate within a predetermined range, accepting the registration.
2. The method of claim 1 , if the touchpoint fiducial registration technique is selected, further comprising:
selecting a fiducial marker;
registering the fiducial marker;
running an executable instruction comprising a fiducial-matching algorithm;
updating a current registration; and
observing and determining whether the current registration is sufficiently accurate within a predetermined accuracy range;
if the current registration is sufficiently accurate, reviewing and determining whether the current registration is sufficiently accurate within a predetermined accuracy range;
if the current registration is insufficiently accurate and another fiducial marker is available, selecting a fiducial marker;
if the current registration is insufficiently accurate and another fiducial marker is unavailable, commencing tracing a surface;
if the initial registration is adequate, accepting the initial registration and commencing tracing a surface; and,
if the initial registration is inadequate, iteratively touching and registering a plurality of facial features until a sufficient number of facial features are captured.
3. The method of claim 2 , if the touchpoint fiducial registration technique is selected, further comprising:
if the current registration is sufficiently accurate, accepting the current registration; and,
if the current registration is insufficiently accurate, performing one of:
selecting a fiducial marker;
commencing tracing a surface, such as by collecting points; and
recalculating the current registration.
4. The method of claim 2 , if the touchpoint fiducial registration technique is selected, further comprising:
in foreground, running an executable instruction comprising a surface-matching algorithm while blocking the user interaction;
updating the current registration; and
reviewing and determining whether the current registration is sufficiently accurate, such as by being within a predetermined accuracy range.
5. The method of claim 2 , if the touchpoint fiducial registration technique is selected, further comprising:
collecting a plurality of points; and
observing and determining whether the current registration is sufficiently accurate, such as by being within a predetermined accuracy range;
if the current registration is sufficiently accurate, terminating tracing of the surface, such as by terminating collecting the plurality of points; and
reviewing and determining whether the current registration is sufficiently accurate, such as by being within a predetermined accuracy range.
6. The method of claim 2 , if the touchpoint fiducial registration technique is selected, further comprising:
in background, determining whether a number of collected points exceeds 50 and whether the number of collected points is divisible by 10;
if the number of collected points exceeds 50 and the number of collected points is divisible by 10, running an executable instruction comprising a surface-matching algorithm using an initial registration;
updating the current registration; and,
in background, observing and determining whether the current registration is sufficiently accurate, such as by being within a predetermined accuracy range; and,
if the number of collected points does not exceed 50 and the number of collected points is not divisible by 10, collecting a plurality of points.
7. The method of claim 1 , if the surface-trace technique is selected, further comprising:
iteratively touching and registering a plurality of facial features until a sufficient number of facial features are captured;
if sufficient facial features are captured, reviewing and determining whether the initial registration is adequate;
if the initial registration is adequate, accepting the initial registration;
commencing tracing a surface, such as by collecting points; and
if the initial registration is inadequate, iteratively touching and registering a plurality of facial features until a sufficient number of facial features are captured.
8. The method of claim 1 , if the surface-trace technique is selected, further comprising:
running an executable instruction comprising a surface-matching algorithm;
in background, updating the initial registration; and
reviewing and determining whether the initial registration is sufficiently accurate within a predetermined accuracy range.