Path planning and collision avoidance for movement of instruments in a radiation therapy environment
Apparatus and methods for therapy delivery are disclosed. In one embodiment, a therapy delivery system includes a plurality of movable components including a radiation therapy nozzle and a patient pod for holding a patient, a patient registration module for determining a desired position of at least one of the plurality of movable components, and a motion control module for coordinating the movement of the least one of the plurality of movable components from a current position to the desired position. The motion control module includes a path planning module for simulating at least one projected trajectory of movement of the least one of the plurality of moveable components from the current position to the desired position.
1. A radiation therapy system operable to selectively deliver radiation along a delivery axis from one or more angles or orientations with respect to a beam delivery aiming point comprising:
a radiation source operable to irradiate a radiation beam along a radiation beam axis;
a gantry operable to revolve relatively precisely about a gantry isocenter wherein the radiation source is attached and supported by the gantry;
a nozzle attached and supported by the gantry, wherein an aperture is positioned on the distal end of the nozzle and the radiation beam passes through and is shaped by the aperture;
the gantry and nozzle being responsive to received instructions to be positioned relative to a nominal beam delivery aiming point subject to certain amounts of structural flex and movement tolerances from nominal positions and orientations;
a camera system operable to obtain images of moveable components of the radiation therapy system and process the obtained images to determine position measurements of the gantry;
internal monitoring systems that also monitor the movement of the gantry and the nozzle and provide signals indicative thereof; and
a control system operable to receive position measurements from the camera system and utilize the received position measurements to determine an offset between the actual location of the radiation source attached to the gantry and an expected location of the radiation source attached to the gantry positioned in accordance with the received instructions;
wherein the control system monitors signals from the camera system and the internal monitoring systems and inhibits movement of the moveable components if the signals indicate that a collision of the moveable components is likely to occur.
2. The radiation therapy system of claim 1 wherein the control system is operable to utilize a determined offset between actual and expected positions of the radiation source to determine an error between a presumed nominal beam delivery aiming point and an actual beam delivery aiming point.
3. The radiation therapy system of claim 1 wherein the camera system comprises one or more cameras operable to image distinctive monuments of the moveable components to monitor their physical location.
4. The radiation therapy system of claim 3 wherein the monuments comprise markers attached to selected regions of the movable components of the radiation therapy system.
5. The radiation therapy system of claim 4 wherein the control system determines the spatial and angular orientation of moveable components of the radiation therapy system by determining the location and position of the markers attached to selected regions of the moveable components of the radiation therapy system.
6. The radiation therapy system of claim 4 , wherein multiple cameras of the camera system obtain position measurements of a single marker so as to provide a more accurate measurement of the single marker's location than provided by a single external measurement device.
7. The radiation therapy system of claim 1 wherein the internal monitoring systems comprise one or more local position feedback devices selected from a group consisting of: rotary encoders, linear encoders and servos associated with one or more of the moveable components of the radiation therapy system.
8. The radiation therapy system of claim 1 further comprising:
a patient pod configured to hold a patient in place and substantially inhibit any relative movement of a patient with respect to the patient pod; and
a patient positioner is adapted to, upon receipt of movement commands, position the patient pod in one or more translational and rotational axes;
wherein the camera system is arranged to determine position measurements of the patient pod and the control system is operable to utilize the position measurements to determine an offset between the actual position of the patient pod and an expected position of the patient pod.
9. The radiation therapy system in accordance with claim 8 wherein the patient pod comprises an immobilizing device selected from a group consisting of: expandable foam, bite blocks, and fitted face masks.
10. A monitoring system for monitoring a radiation therapy system having movable components operable to position a radiation source relative to a nominal beam delivery aiming point in accordance with received instructions, wherein the movable components of the radiation therapy system are subject to certain amounts of structural flex and movement tolerances from nominal positions and orientations, the monitoring system comprising:
a camera system operable to obtain images of moveable components of the radiation therapy system and process the obtained images to determine position measurements of the moveable components of a monitored radiation therapy system positioning a radiation source relative to a nominal beam delivery aiming point;
internal monitoring systems that also monitor the movement of moveable components of a monitored radiation therapy system positioning a radiation source relative to a nominal beam delivery aiming point and provide signals indicative thereof; and
a control system operable to receive position information from the camera system and utilize the received position information to determine an offset between the actual location of the radiation source and an expected location of the radiation source positioned in accordance with instructions received by the monitored radiation therapy system
wherein the control system monitors signals from the camera system and the internal monitoring systems and inhibits movement of the moveable components if the signals indicate that a collision of the moveable components is likely to occur.
11. The monitoring system of claim 10 wherein the control system is operable to utilize the determined offset between actual and expected positions of the radiation source to determine an error between a presumed nominal beam delivery aiming point and an actual beam delivery aiming point .
12. The monitoring system of claim 10 wherein the camera system comprises one or more cameras operable to monitor the location of one or more markers attached to moveable components of a monitored radiation therapy system positioning a radiation source relative to a nominal beam delivery aiming point.
13. The monitoring system of claim 12 wherein the control system is operable to determine the spatial and angular orientation of moveable components of a monitored radiation therapy system by determining the location and position of markers attached to moveable components of a monitored radiation therapy system.
14. The monitoring system of claim 10 wherein the internal monitoring systems comprise one or more local position feedback devices selected from a group consisting of: rotary encoders, linear encoders and servos associated with one or more of the moveable components of the radiation therapy system.