Patent ID: 8309941

Claim:
An apparatus for controlling extraction of charged particles from a synchrotron for irradiation therapy of a tumor of a patient, comprising: a synchrotron configured to accelerate the charged particles, said synchrotron comprising: a radio-frequency cavity system comprising a first pair of blades for inducing oscillation of the charged particles; and a foil configured to yield slowed charged particles from the charged particles having sufficient oscillation to traverse said foil, wherein the slowed charged particles pass through a second pair of blades having an extraction voltage directing the charged particles out of said synchrotron through a Lamberson extraction magnet, said radio-frequency cavity system for inducing oscillation configured and timed using said respiration signal; a respiration sensor generating a respiration signal, said respiration signal corresponding to a variable rate breathing pattern of the patient, said respiration sensor comprising at least one of: a force meter strapped to the patient's chest; a first thermal resistor configured in a first position proximate an exhalation path of the patient; and a second thermal resistor configured in a second position both out of the exhalation path of the patient and in a local room environment common with the patient, wherein said respiration signal is generated using differences between readings from said first thermal resistor and said second thermal resistor, wherein said radio-frequency cavity system for inducing oscillation is timed using said respiration signal to time extraction of the charged particles to the tumor based on said variable rate breathing pattern.