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US 6,639,967 B2Granted
Electron gun heating control to reduce the effect of back heating in medical linear accelerators
AssigneeSiemens Medical Solutions USA, Inc.
InventorsMichael John Marziale, Francisco M. Hernandez-Guerra
Life of this patent
Estimating the term…
Abstract
A radiation therapy device (2) includes a programmable power source (300) and controller (302) that monitor an injected current level and controls heater voltage in response thereto. The heater voltage is reduced in predetermined increments without affecting the beam profile.
Claims21
A radiation therapy apparatus, comprising:
- an electron gun;
- an injector coupled to said electron gun and adapted to provide injector pulses to control said electron gun;
- a measurement unit adapted to measure an injector current;
- and
- a trigger system adapted to adjust a filament voltage responsive to signals from said measurement unit indicative of said injector current and responsive to activation of a backheating compensation function.
2 more elements
A radiation therapy apparatus, comprising:
- an electron gun;
- an injector coupled to said electron gun and adapted to provide injector pulses to control said electron gun;
- a measurement unit adapted to measure an injector current;
- and
- a trigger system adapted to adjust a filament voltage responsive to signals from said measurement unit indicative of said injector current, said trigger system including a programmable power source and a signal processing controller for generating a DC signal to said programmable power source responsive to an injector current signal from said current measurement unit and an injection trigger system.
2 more elements
A method for delivering radiation therapy, comprising:
- setting a filament voltage and an injector current;
- measuring an actual injector current during a run up phase;
- incrementally decreasing said filament voltage at RAD ON;
- measuring said injector current during a RAD ON phase;
- determining if said injector current is greater than a predetermined threshold;
- and
- incrementally decreasing said filament voltage if said injector current is above said threshold.
4 more elements
A method, comprising:
- providing an electron gun;
- providing an injector coupled to said electron gun and adapted to provide injector pulses to control said electron gun;
- providing a measurement unit adapted to measure an injector current;
- and
- providing a trigger system adapted to adjust a filament voltage responsive to signals from said measurement unit indicative of said injector current and responsive to activation of a backheating compensation function.
2 more elements
A method, comprising:
- providing an electron gun;
- providing an injector coupled to said electron gun and adapted to provide injector pulses to control said electron gun;
- providing a measurement unit adapted to measure an injector current;
- and
- providing a trigger system adapted to adjust a filament voltage responsive to signals from said measurement unit indicative of said injector current, said trigger system including a programmable power source and a signal processing controller for generating a DC signal to said programmable power source responsive to an injector current signal from said current measurement unit and an injection trigger system.
2 more elements
A radiation therapy device, comprising:
- an electron gun having a filament;
- a controller operable to set a filament voltage and an injector current level;
- a measuring unit adapted to measure an actual injector current level;
- and
- a trigger system adapted to adjust said filament voltage if said actual injector current level is above a predetermined threshold.
2 more elements
A radiation therapy apparatus, comprising:
- an electron gun;
- and
- a backheating compensation system, comprising:
- an injector coupled to said electron gun and adapted to provide injector pulses to control said electron gun;
- a measurement unit adapted to measure an injector current;
- and
- a trigger system adapted to adjust a filament voltage responsive to signals from said measurement unit indicative of said injector current and responsive to activation of a backheating compensation control signal.
4 more elements
Dependencies are inferred from the claim text.