Systems, devices, and methods for tracking moving targets

A motion compensation system for tracking and compensating for subject motion during a medical imaging scan, the motion compensation system comprising:

• an optical target configured to be fixed to a subject;
• at least two detectors positioned so as to view the optical target from different directions with each of the at least two detectors being configured to record two dimensional images of the optical target;
• one or more computer readable storage devices configured to store a plurality of computer executable instructions;
• and
• one or more hardware computer processors in communication with the one or more computer readable storage devices and configured to execute the plurality of computer executable instructions in order to cause the system to determine a position of the subject, wherein the determining the position of the subject comprises:
• identifying the optical target and displacement of the optical target based on optical images collected by the at least two detectors;
• utilizing an iteration procedure, wherein the iteration procedure comprises testing an approximate first-order solution against the identified optical target to determine residual errors and dividing the determined residual errors by local derivatives with respect to rotation and translation to determine an iterative correction;
• repeating the iteration procedure until the residual errors are within predetermined levels of accuracy;
• and
• utilizing the repeated iteration procedure to determine the position of the subject at rates of at least 100 times per second.

A computer-implemented method for tracking and compensating for subject motion during a medical imaging scan, the computer-implemented method comprising:

• positioning at least two detectors so as to view an optical landmark on a subject from different directions with each of the at least two detectors being configured to record two dimensional images of the optical landmark;
• and
• determining, by a computer system, a position of the subject, wherein the determining the position of the subject comprises:
• identifying the optical landmark and displacement of the optical landmark based on optical images collected by the at least two detectors;
• utilizing an iteration procedure, wherein the iteration procedure comprises testing an approximate first-order solution against the identified optical landmark to determine residual errors and dividing the determined residual errors by local derivatives with respect to rotation and translation to determine an iterative correction;
• repeating the iteration procedure until the residual errors are within predetermined levels of accuracy;
• and
• utilizing the repeated iteration procedure to determine the position of the subject,
• wherein the computer system comprises a computer processor and an electronic storage medium.

A motion compensation system for tracking and compensating for subject motion during a magnetic resonance (MR) scan, the motion compensation system comprising:

• a magnetic resonance (MR) scanner;
• at least two detectors positioned so as to view an optical landmark on a subject from different directions with each of the at least two detectors being configured to record two dimensional images of the optical landmark;
• one or more computer readable storage devices configured to store a plurality of computer executable instructions;
• and
• one or more hardware computer processors in communication with the one or more computer readable storage devices and configured to execute the plurality of computer executable instructions in order to cause the system to determine a position of the subject, wherein the determining the position of the subject comprises:
• identifying the optical landmark and displacement of the optical landmark based on optical images collected by the at least two detectors;
• utilizing an iteration procedure, wherein the iteration procedure comprises testing an approximate first-order solution against the identified target point to determine residual errors and dividing the determined residual errors by local derivatives with respect to rotation and translation to determine an iterative correction;
• repeating the iteration procedure until the residual errors are within predetermined levels of accuracy;
• and
• utilizing the repeated iteration procedure to determine the position of the subject at rates of at least 100 times per second.