Fluoroscopic robotic prosthetic implant system and methods
Techniques for robotically guiding a cup-shaped implant or instrument are provided. In an example, the technique can include a combination of the following operations. Acquiring a calibration image including a cup-shaped element in a first orientation. Identifying a first elliptical outline of the cup-shaped element. Acquiring a navigation image including the cup-shaped element in a second orientation. Identifying a second elliptical outline of the cup-shaped element. Aligning a coordinate system of a robotic system to a patient, and positioning an implant or instrument based on a pre-operative plan within the coordinate system.
1 . A method to navigate an instrument relative to anatomy of a patient, the method comprising:
acquiring a calibration image from a medical imaging device, the calibration image including a portion of the anatomy and an instrument in a first position and orientation relative to a virtual coordinate system, the instrument including a cup-shaped element affixed to a distal end;
identifying a first plurality of patient landmarks on the portion of the anatomy in the calibration image;
identifying a first elliptical outline of an opening of the cup-shaped element in the calibration image;
acquiring a navigation image from the medical imaging device, the navigation image including the portion of anatomy, the cup-shaped element and the instrument at a second position and orientation;
identifying a second plurality of patient landmarks on the portion of anatomy in the navigation image;
identifying a second elliptical outline of the opening of the cup-shaped element in the navigation image;
aligning the virtual coordinate system to a frame of reference of the anatomy of the patient using the first elliptical outline and the second elliptical outline; and
output a registration transformation between the virtual coordinate system and the frame of reference of the anatomy of the patient.
2 . The method of claim 1 , wherein acquiring the calibration image includes receiving the calibration image on a handheld computing device from the medical imaging device.
3 . The method of claim 1 , wherein identifying the first plurality of patient landmarks include identifying a teardrop, a brim line, and an obturator foramen contour.
4 . The method of claim 1 , wherein identifying the first elliptical outline or the second elliptical outline of the opening of the cup-shaped element includes receiving a manual adjustment of a position, a size, or an orientation of the first elliptical outline or the second elliptical outline.
5 . The method of claim 1 , wherein identifying the first elliptical outline or the second elliptical outline of the opening of the cup-shaped element includes identifying a region-of-interest containing an elliptical contour using a Hough transform.
6 . The method of claim 1 , wherein aligning the virtual coordinate system to the frame of reference of the anatomy includes computing a first transformation between a first image position of the instrument in coordinates of the calibration image and a second image position of the instrument in coordinates of the navigation image.
7 . The method of claim 6 , wherein aligning the virtual coordinate system to the frame of reference of the anatomy includes computing a second transformation between a first robot position of the instrument in coordinates of the virtual coordinate system and a second robot position of the instrument in of the virtual coordinate system.
8 . The method of claim 7 , wherein aligning the virtual coordinate system to the frame of reference of the anatomy includes aligning the first transformation and the second transformation to register the navigation image in the virtual coordinate system.
9 . The method of claim 1 , wherein aligning the virtual coordinate system to the frame of reference of the anatomy includes aligning the calibration image and the navigation image using the first plurality of patient landmarks and the second plurality of patient landmarks.
10 . The method of claim 9 , wherein aligning the calibration image and the navigation image includes calculating a first angle between brim lines in the calibration image and the navigation image and calculating a second angle between teardrop to barycenter of foramen axes lines in the calibration image and navigation image.
11 . The method of claim 10 , wherein aligning the calibration image and the navigation image includes applying a rotation equal to an average of the first angle and the second angle.
12 . The method of claim 11 , wherein aligning the calibration image and the navigation image includes matching foramen contours and brim line points across the calibration image and the navigation image to determine scaling and rotation.
13 . The method of claim 12 , wherein matching foramen contours and brim line points includes using an iterative closest point algorithm to determine the scaling and rotation.
14 . The method of claim 1 , wherein acquiring the calibration image from the medical imaging device includes displaying an instruction to position the instrument at a pre-defined inclination angle and a pre-defined anteversion angle relative to the anatomy of the patient.
15 . The method of claim 14 , wherein acquiring the navigation image from the medical imaging device includes displaying an instruction to position the instrument at a second pre-defined inclination angle and a second anteversion angle relative to the anatomy of the patient.
16 . The method of claim 1 , further comprising registering the anatomy of the patient to an imaging coordinate system.
17 . The method of claim 1 , further comprising validating a target orientation of the cup-shaped element including validating inclination and anteversion.
18 . A method comprising:
determining a first acetabular cup elliptical outline within a first fluoroscopic image including an acetabular cup impaction instrument in a first position, the acetabular cup impaction instrument including an acetabular cup affixed to a distal end;
determining a second acetabular cup elliptical outline within a second fluoroscopic image including the acetabular cup impaction instrument in a second position;
aligning a virtual coordinate system to a target coordinate system associated with the first fluoroscopic image and the second fluoroscopic image using the first acetabular cup elliptical outline and the second acetabular cup elliptical outline, wherein the target coordinate system is one of a coordinate system relative to a fluoroscopic imaging device or a coordinate system relative to anatomy of a patient; and
output a registration transformation between the virtual coordinate system and the target coordinate system.
19 . The method of claim 18 , wherein the aligning the virtual coordinate system to the target coordinate system includes:
calculating a first transformation between the first acetabular cup elliptical outline and the second acetabular cup elliptical outline;
calculating a second transformation between the first position of the acetabular cup impaction instrument and the second position of the acetabular cup impaction instrument; and
aligning the virtual coordinate system with the target coordinate system based on the first transformation and the second transformation.
20 . A system comprising:
a fluoroscope configured to capture fluoroscopic images of a portion of anatomy of a patient;
an acetabular cup impaction instrument adapted to impact an acetabular cup into an acetabula of the patient; and
a computing device including a processor and a memory device, the memory device including instructions that, when executed by the processor, cause the processor to perform operations including:
determining a first acetabular cup ellipse within a first fluoroscopic image generated by the fluoroscope, the first fluoroscopic image including the acetabular cup impaction instrument in a first position, the acetabular cup impaction instrument including the acetabular cup affixed to a distal end;
determining a second acetabular cup ellipse within a second fluoroscopic image generated by the fluoroscope, the second fluoroscopic image including the acetabular cup impaction instrument in a second position;
aligning an instrument coordinate system to an image coordinate system associated with the fluoroscope using the first acetabular cup ellipse and the second acetabular cup ellipse;
receiving a target inclination and a target anteversion for impaction of the acetabular cup; and
generating commands to position the acetabular cup impaction instrument into a position and an orientation to align the acetabular cup to the target inclination and the target anteversion.