Method and apparatus for radiation therapy
CA 2091275 C · Owner: Holmes, Timothy · Inventors: Mackie, Thomas Rockwell; Swerdloff, Stuart; Holmes, Timothy
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A radiation therapy apparatus includes a compensator having a plurality of leaves to divide the radiation beam into rays each of which may be effectively and individually attenuated over a range of attenuations by controlling the duty cycle of the leaves position between the open and closed states. An apparatus for controlling the compensator accounts for scattering of radiation through the deconvolution of a terma map and calculates a sinogram for controlling the compensator at a variety of angles about a patient using iterated forward and back projections efficiently calculated in frequency space.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed March 9, 1993 and granted January 7, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 9, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 9, 2015.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.