Methods and systems for tracking and guiding sensors and instruments
A shared-housing ultrasound transducer and machine-vision camera system is disclosed for registering the transducer's x, y, z position in space and pitch, yaw, and roll orientation with respect to an object, such as a patient's body. The position and orientation are correlated with transducer scan data, and scans of the same region of the object are compared in order to reduce ultrasound artifacts and speckles. The system can be extended to interoperative gamma probes or other non-contact sensor probes and medical instruments. Methods are disclosed for computer or remote guiding of a sensor probe or instrument with respect to saved positions and orientations of the sensor probe.
1. A spatial registration apparatus comprising:
a gamma ray detector;
a camera rigidly connected with the gamma ray detector;
a fiducial marker affixed to an object of interest, the object of interest being different from the gamma ray detector and different from the camera; and
at least one processor operatively coupled with a memory, the memory having instructions for execution by the at least one processor, wherein the memory stores a relative location and orientation between the gamma ray detector and the rigidly connected camera, wherein the instructions, when executed by the at least one processor, cause the at least one processor to determine a pose of the camera with respect to the fiducial marker using an image of the fiducial marker captured by the camera and then transform the pose, using the stored relative location and orientation between the gamma ray detector and rigidly attached camera, to determine a first spatial position and orientation of the gamma ray detector with respect to the fiducial marker, the at least one processor associating scanning data from the gamma ray detector with the first spatial position and orientation of the gamma ray detector to create a first spatially registered scan, the scanning data from the gamma ray detector being time synchronized with the first spatial position and orientation of the gamma ray detector.
2. The apparatus of claim 1 , wherein the fiducial marker includes binary coding.
3. The apparatus of claim 1 , further comprising a flexible tape having the fiducial marker, wherein the at least one processor is configured to determine the spatial position and orientation of the gamma ray detector with respect to the object using an image captured by the camera of the fiducial marker of the flexible tape on the object.
4. The apparatus of claim 3 , wherein the object has a curved surface, and the flexible tape is conformed to the curved surface.
5. The apparatus of claim 3 , wherein the fiducial marker has a rigid substrate, the flexible tape including two or more rigid substrate fiducial markers piece-wise rotatable with respect to each other.
6. The apparatus of claim 1 , wherein the gamma ray detector includes a Compton imager or a collimator based imager.
7. The apparatus of claim 1 , wherein the gamma ray detector includes a gamma ray probe that includes a semiconductor detector or scintillator.
8. The apparatus of claim 1 , wherein the instructions for execution by the at least one processor further cause the processor to:
construct a three-dimensional (3-D) model of a radioactive tracer in a tissue with respect to the object using the first spatially registered scan; and
display, on a display, the 3-D model of the radioactive tracer with respect to an outline of a body of a subject.
9. A method for viewing a radioactive tracer within tissue of a subject, the method comprising:
affixing a fiducial marker to a subject;
passing a gamma ray detector and a camera over the subject, the camera being rigidly connected with the gamma ray detector;
acquiring scanning data of a radioactive tracer within the subject from the gamma ray detector;
imaging the fiducial marker while acquiring the scanning data;
determine a pose of the camera with respect to the fiducial marker using an image captured by the camera;
obtaining a stored relative location and orientation between the gamma ray detector and the rigidly connected camera;
transforming the pose using the relative location and orientation to determine a first spatial position and orientation of the gamma ray detector with respect to the fiducial marker;
associating the first spatial position and orientation of the gamma ray detector with the scanning data from the gamma ray detector to create a first spatially registered scan, the scanning data from the gamma ray detector being time synchronized with the first spatial position and orientation of the gamma ray detector;
building a three-dimensional (3-D) model of the radioactive tracer using the first spatially registered scan; and
deriving visualization data from the 3-D model.
10. The method of claim 9 , further comprising:
emitting a signal from the camera;
detecting a reflection of the signal from the subject; and
determining a distance from the camera to at least three points on a surface of the subject based on the reflection of the signal.
11. The method of claim 9 , further comprising displaying the 3-D model of the radioactive tracer with respect to an outline of a body of the subject.
12. The method of claim 9 , wherein the radioactive tracer includes Tc-99 m.
13. The method of claim 9 , further comprising displaying the visualization data.
14. The method of claim 9 , further comprising passing the visualization data over a network to a user who is remote from the subject.
15. The method of claim 9 , wherein the fiducial marker includes binary coding.
16. The method of claim 9 , wherein the fiducial marker includes one or more light emitting diodes (LEDs).
17. The method of claim 9 , wherein the fiducial marker is attached to a flexible tape, and wherein the subject has a curved surface, and the flexible tape is conformed to the curved surface.
18. The method of claim 9 , wherein the fiducial marker is attached to a flexible tape, and wherein the fiducial marker has a rigid substrate, the flexible tape including two or more rigid substrate fiducial markers piece-wise rotatable with respect to each other.
19. The method of claim 9 , wherein the gamma ray detector includes a Compton imager or a collimator based imager.
20. The method of claim 9 , wherein the gamma ray detector includes a gamma ray probe that includes a semiconductor detector or scintillator.