# US 11,896,850 B2 · Online angle selection in rotational imaging and tracking systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,896,850 B2 - Document ID: US11896850B2 - Status: Granted - Kind: B2 - Application number: 17/721,216 - Filed: 2022-04-14 - Published: 2022-08-04 - Granted: 2024-02-13 - Earliest claimed: 2016-08-29 - Assignees: Accuray Incorporated - Applicants: Accuray Incorporated - Inventors: Petr Jordan; Andriy Myronenko; Calvin Maurer; Eric Schnarr; Rob O'Connell - Web page: https://patentgrep.com/patent/US11896850B2 ## CPC - A61N 5/107: {in real time, i.e. during treatment} - A61B 6/4014: {arranged in multiple source-detector units} - A61N 5/103: {Treatment planning systems} - A61N 5/1037: {taking into account the movement of the target, e.g. 4D-image based planning} - A61N 5/1039: {using functional images, e.g. PET or MRI} - A61N 5/1049: {for verifying the position of the patient with respect to the radiation beam} - A61N 5/1081: {Rotating beam systems with a specific mechanical construction, e.g. gantries} - A61N 5/1083: {Robot arm beam systems} - A61N 2005/1061: {using an x-ray imaging system having a separate imaging source} - A61N 2005/1062: {using virtual X-ray images, e.g. digitally reconstructed radiographs [DRR]} - A61N 2005/1074: {Details of the control system, e.g. user interfaces} - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A method of operating a radiation apparatus is described. The method includes selecting at least a first angle and a second angle from a set of angles for a first rotation of a gantry of a radiation apparatus. The method also includes generating, using an imaging device mounted to the gantry, a first tracking image of a target from the first angle during the first rotation of the gantry. The method further includes generating, using the imaging device, a second tracking image of the target from the second angle during the first rotation of the gantry. ## Claims ### Claim 1 A method of operating a radiation apparatus, the method comprising: selecting at least a first angle and a second angle from a set of angles for a first rotation of a gantry of a radiation apparatus, wherein the first angle is selected from the set of angles based on having a tracking quality metric value satisfying a tracking quality metric criterion, wherein the tracking quality metric value includes a numerical value representing a confidence that a target is trackable based on images generated at the first angle, and wherein the tracking quality metric criterion includes a numerical threshold; generating, using an imaging device mounted to the gantry, a first tracking image of the target from the first angle during the first rotation of the gantry; and generating, using the imaging device, a second tracking image of the target from the second angle during the first rotation of the gantry. ### Claim 2 (depends on 1) The method of claim 1, wherein the tracking quality metric value of the first angle is higher than a second tracking quality metric value of the second angle, and wherein the second angle has a separation from the first angle of at least an angle separation threshold. ### Claim 3 (depends on 1) The method of claim 1, further comprising: determining, based on the second tracking image, that target tracking has failed during delivery of a radiation treatment beam; determining a time window within which a next tracking image must be taken; determining that no angle from the set of angles will be available within the time window; and interrupting delivery of the radiation treatment beam. ### Claim 4 (depends on 1) The method of claim 1, further comprising: generating a plurality of x-ray images of the target from two or more angles from the set of angles; and generating a motion model of the target from the plurality of x-ray images. ### Claim 5 (depends on 1) The method of claim 1, wherein the method is performed during an alignment phase of operation of the radiation apparatus. ### Claim 6 (depends on 1) The method of claim 1, wherein the method is performed during a treatment stage of operation of the radiation apparatus. ### Claim 7 A computer-readable medium comprising instructions that when executed by a process device, cause the processing device to: select at least a first angle and a second angle from a set of angles for a first rotation of a gantry of a radiation apparatus, wherein the first angle is selected from the set of angles based on having a tracking quality metric value satisfying a tracking quality metric criterion, wherein the tracking quality metric value includes a numerical value representing a confidence that a target is trackable based on images generated at the first angle, and wherein the tracking quality metric criterion includes a numerical threshold; generate, using an imaging device mounted to the gantry, a first tracking image of the target from the first angle during the first rotation of the gantry; and generate, using the imaging device, a second tracking image of the target from the second angle during the first rotation of the gantry. ### Claim 8 (depends on 7) The computer-readable medium of claim 7, wherein the tracking quality metric value of the first angle is higher than a second tracking quality metric value of the second angle, and wherein the second angle has a separation from the first angle of at least an angle separation threshold. ### Claim 9 (depends on 7) The computer-readable medium of claim 7, wherein the instructions further cause the processing device to: determine, based on the second tracking image, that target tracking has failed during delivery of a radiation treatment beam; determine a time window within which a next tracking image must be taken; determine that no angle from the set of angles will be available within the time window; and interrupt delivery of the radiation treatment beam. ### Claim 10 (depends on 7) The computer-readable medium of claim 7, wherein the instructions further cause the processing device to: generate a plurality of x-ray images of the target from two or more angles from the set of angles; and generate a motion model of the target from the plurality of x-ray images. ### Claim 11 (depends on 7) The computer-readable medium of claim 7, wherein the instructions are executed by the processing device during an alignment phase of operation of the radiation apparatus. ### Claim 12 (depends on 7) The computer-readable medium of claim 7, wherein the instructions are executed by the processing device during a treatment stage of operation of the radiation apparatus. ### Claim 13 A method of operating a radiation apparatus, the method comprising: selecting at least a first angle from a set of angles for a first rotation of a gantry of a radiation apparatus, wherein the first angle is selected from the set of angles based on having a tracking quality metric value satisfying a tracking quality metric criterion, wherein the tracking quality metric value includes a numerical value representing a confidence that a target is trackable based on images generated at the first angle, and wherein the tracking quality metric criterion includes a numerical threshold; generating, using an imaging device mounted to the gantry, a first tracking image of the target from the first angle during the first rotation of the gantry; and performing target tracking based on the first tracking image. ### Claim 14 (depends on 13) The method of claim 13, further comprising: generating a plurality of x-ray images of the target from two or more angles from the set of angles; and generating a motion model of the target from the plurality of x-ray images. ### Claim 15 (depends on 13) The method of claim 13, wherein the method is performed during a treatment stage of operation of the radiation apparatus.