Vision Rt Limited

Edward William Mead

Ivan Daniel Meir

Adrian Roger William Barrett

James Mathew Hughes, Ii

Michael James Tallhamer

James Mathew Hughes Ii

A method of calibrating a monitoring system () is described in which a calibration phantom () is located with its center located approximately at the isocenter of a treatment room through which a treatment apparatus () is arranged to direct radiation, wherein the surface of the calibration phantom () closest to an image capture device () of the monitoring system () is inclined approximately 45° relative to the camera plane of an image capture device of the monitoring system. Images of the calibration phantom () are then captured using the image capture device () and the images are processed to generate a model of the imaged surface of the calibration phantom. The generated model of the imaged surface of the calibration phantom () is then utilized to identify the relative location of the center of the calibration phantom () and the camera plane of the image capture device () which is then utilized to determine the relative location of the camera plane of the image capture device and the isocenter of a treatment room.

Method of calibrating a patient monitoring system for use with a radiotherapy treatment apparatus

Some embodiments are directed to an image director of a patient monitoring system to obtain calibration images of a calibration sheet or other calibration object at various orientations and locations. The images are then stored and processed to calculate camera parameters defining the location and orientation of the image detector and identifying internal characteristics of the image detector, and the information are stored. The patient monitoring system can be re-calibrated by using the image detector to obtain an additional image of a calibration sheet or calibration object. The additional image and the stored camera parameters are then used to detect any apparent change in the internal characteristics of the image detector ()(S-).

A method of calibrating a monitoring system () is described in which a calibration phantom () is located with its center located approximately at the isocenter of a treatment room through which a treatment apparatus () is arranged to direct radiation, wherein the surface of the calibration phantom () closest to an image capture device () of the monitoring system () is inclined approximately 45&#xb0; relative to the camera plane of an image capture device of the monitoring system. Images of the calibration phantom () are then captured using the image capture device () and the images are processed to generate a model of the imaged surface of the calibration phantom. The generated model of the imaged surface of the calibration phantom () is then utilized to identify the relative location of the center of the calibration phantom () and the camera plane of the image capture device () which is then utilized to determine the relative location of the camera plane of the image capture device and the isocenter of a treatment room.

A calibration sheet is located at a first position where its surface substantially corresponds to the expected position of a patient surface lying on a mechanical couch during treatment. Images of the calibration sheet are obtained and processed to ascertain relative locations and orientations of the image detectors obtaining the images and optical distortion parameters indicative of optical distortions present in the obtained images of the calibration sheet. The calibration sheet is then re-located to a known position relative to the iso-centre of the treatment apparatus and images of the re-located calibration sheet are obtained and processed to determine a transform corresponding to the relocation of the calibration sheet from the first position to the iso-centre of the treatment apparatus. Data indicative of optical distortions present in the images and data indicative of the locations and orientations of the image detectors relative to the iso-centre of the treatment apparatus are stored.

A patient monitoring system for monitoring a patient undergoing radiotherapy comprising a projector operable to project a pattern of light onto a patient undergoing radiation treatment, a patient restraint operable to restrain the patient relative to a treatment apparatus, an image detector operable to obtain images of the patient, and a model generation module operable to process images of the patient obtained by the image detector to generate a model of the surface of a portion of the patient, wherein at least a portion of the patient restraint is colored and the model generation module is inhibited from generating a model of the colored portion of the patient restraint.

Patient monitoring system

Some embodiments are directed to an image director of a patient monitoring system to obtain calibration images of a calibration sheet or other calibration object at various orientations and locations. The images are then stored and processed to calculate camera parameters defining the location and orientation of the image detector and identifying internal characteristics of the image detector, and the information are stored. The patient monitoring system can be re-calibrated by using the image detector to obtain an additional image of a calibration sheet or calibration object. The additional image and the stored camera parameters are then used to detect any apparent change in the internal characteristics of the image detector () (S-).

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London, United Kingdom

Edward William Mead