Method for use with a radiotherapy device

A method of determining whether repair or replacement of an electron gun of a radiotherapy device should be scheduled, the radiotherapy device comprising a linear accelerator and being configured to provide therapeutic radiation to a patient, the radiotherapy device comprising:

• a vacuum tube comprising the electron gun, a waveguide configured to accelerate electrons emitted by the electron gun toward a target to produce the therapeutic radiation;
• and a current sensor, the current sensor being configured to provide a signal indicative of current supplied to the electron gun;
• the method comprising:
• receiving a voltage value derived from a signal provided by a voltage sensor during rotation of a gantry:
• processing the voltage value, wherein processing the voltage value comprises a determination of whether the electron gun is in a standby mode during the rotation of the gantry, and wherein the determination of whether the electron gun is in standby mode is made by a determination of whether the voltage value meets at least one voltage threshold criterion;
• receiving current values derived from the signal provided by the current sensor;
• processing the current values, wherein processing the current values comprises:
• when the current values have fallen below a first threshold current value, determining whether the current values have changed by a first threshold amount in a particular time period;
• and
• when the current values have fallen below a second threshold current value, determining whether the current values have changed by a second threshold amount in the particular time period, wherein the first threshold current value is lower than the second threshold current value, and wherein the first threshold amount is smaller than the second threshold amount;
• and
• based on the processed current values, determining that repair or replacement of the electron gun should be scheduled when either:
• I) the current values have fallen below the first threshold current value and have changed by at least the first threshold amount in the particular time period, or ii) the current values have fallen below the second threshold current value and the current values have changed by at least the second threshold amount in the particular time period.

A system for determining a nature of a fault in a radiotherapy device configured to provide therapeutic radiation to a patient, the system comprising:

• the radiotherapy device, the radiotherapy device comprising:
• a linear accelerator;
• a gantry configured to rotate a vacuum tube around a patient such that radiation is directed toward the patient from multiple angles or directions around the patient, the vacuum tube comprising:
• an electron gun;
• a waveguide configured to accelerate electrons emitted by the electron gun toward a target to produce said radiation;
• a voltage sensor, configured to provide a signal indicative of a voltage applied to the electron gun;
• a current sensor configured to provide a signal indicative of current supplied to the electron gun;
• and
• a processor configured to:
• receive a voltage value derived from signal provided by the voltage sensor during a rotation of the gantry;
• process the voltage value, wherein to process the voltage value comprises a determination of whether the voltage value meets at least one first threshold criterion, wherein processing the voltage value further comprises a determination of whether the electron gun is in a standby mode during the rotation of the gantry, and wherein the determination of whether the electron gun is in standby mode is made by a determination of whether the voltage value meets at least one second threshold criterion;
• and
• based on the processing of the voltage value, determine whether a fault is present in the radiotherapy device, and in response to a determination that a fault is present in the radiotherapy device, determine whether the nature of the fault is associated with the electron gun;
• receive current values derived from the signal provided by the current sensor;
• process the current values, wherein the process the current values includes:
• when the current values have fallen below a first current threshold value, determine whether the current values have changed by a first current threshold amount in a particular time period;
• and
• when the current values have fallen below a second current threshold value, determine whether the current values have changed by a second current threshold amount in the particular time period, wherein the first current threshold value is lower than the second current threshold value, and wherein the first current threshold amount is smaller than the second current threshold amount;
• receive a second voltage value derived from a second signal provided by the voltage sensor;
• process the second voltage value, wherein the process the second voltage value comprises a determination of whether the second voltage value meets at least a fourth threshold criterion;
• and
• based on the processed current values and the processed second voltage value, generate a notification of a fault in the radiotherapy device, wherein the notification includes that the electron gun should be repaired or replaced when either:
• i) the current values have fallen below the first current threshold value and have changed by at least the first current threshold amount in the particular time period, or ii) the current values have fallen below the second current threshold value and the current values have changed at least by the second current threshold amount in the particular time period.