US Pat. No. 9,723,705

CONTROLLING INTENSITY OF A PARTICLE BEAM

Mevion Medical Systems, I...

1. A synchrocyclotron comprising:
a particle source to provide pulses of ionized plasma to a cavity;
a voltage source to provide a radio frequency (RF) voltage to the cavity to accelerate particles from the ionized plasma outwardly;
an extraction channel to receive a beam of particles from the cavity for output from the synchrocyclotron; and
a control system comprising one or more processing devices to control the particle source to provide pulse widths of the ionized
plasma in order to output the beam of particles at an intensity selected from different intensities;

wherein the particle source comprises cathodes to provide voltage to ionize hydrogen to produce the ionized plasma, the cathodes
being unheated by an external source.

US Pat. No. 9,301,384

ADJUSTING ENERGY OF A PARTICLE BEAM

Mevion Medical Systems, I...

1. A particle accelerator comprising:
a coil to provide a magnetic field to a cavity;
a particle source to provide a plasma column to the cavity;
a voltage source to provide a radio frequency (RF) voltage to the cavity to accelerate particles from the plasma column, the
magnetic field causing particles accelerated from the plasma column to move orbitally within the cavity;

an enclosure containing an extraction channel to receive the particles accelerated from the plasma column at an entry point
and to output the particles from the cavity at an exit point; and

a structure arranged proximate to the entry point of the extraction channel to change an energy level of the particles.

US Pat. No. 9,185,789

MAGNETIC SHIMS TO ALTER MAGNETIC FIELDS

Mevion Medical Systems, I...

1. A particle accelerator comprising:
a coil to provide a magnetic field to a cavity;
a cryostat comprising a chamber for holding the coil, the coil being in the chamber to define an interior region of the coil
and an exterior region of the coil;

magnetic structures adjacent to the cryostat, the magnetic structures having one or more slots at least part-way therethrough;
and

one or more magnetic shims in one or more corresponding slots, the one or more magnetic shims being movable to change a magnetic
field produced via the magnetic structures and thereby adjust a position of the coil.

US Pat. No. 9,155,186

FOCUSING A PARTICLE BEAM USING MAGNETIC FIELD FLUTTER

Mevion Medical Systems, I...

1. A particle accelerator comprising:
a voltage source to sweep a radio frequency (RF) voltage in a cavity to accelerate particles from a plasma column, the cavity
having a magnetic field causing particles accelerated from the plasma column to move orbitally within the cavity, the magnetic
field having flux that bows at edges of the cavity;

a regenerator to provide a magnetic field bump within the cavity to thereby change successive orbits of the particles accelerated
from the plasma column so that, eventually, particles output to an extraction point, the regenerator being located at a radius
in the cavity relative to the plasma column; and

ferromagnetic arrangements located in the cavity proximate to the radius, each ferromagnetic arrangement providing a magnetic
field bump, wherein at least two ferromagnetic arrangements are on radially adjacent sides of the regenerator, are separated
from the regenerator by a space, and are configured to at least partly restore vertical focusing of particles in orbit disrupted
by the regenerator.

US Pat. No. 9,622,335

MAGNETIC FIELD REGENERATOR

Mevion Medical Systems, I...

1. A particle accelerator comprising:
a voltage source to provide a radio frequency (RF) voltage to a cavity to accelerate particles from a plasma column, the cavity
having a magnetic field causing particles accelerated from the plasma column to move orbitally within the cavity;

an extraction channel to receive the particles accelerated from the plasma column and to output the received particles from
the cavity; and

a regenerator to provide a magnetic field bump within the cavity to thereby change successive orbits of the particles accelerated
from the plasma column so that, eventually, particles output to the extraction channel, the regenerator comprising at least
one edge comprising a non-orthogonal intersection of two faces;

wherein the magnetic field is at least 6 Tesla and the magnetic field bump is at most 2 Tesla.

US Pat. No. 9,452,301

INNER GANTRY

Mevion Medical Systems, I...

1. A system comprising:
a patient support to support a patient;
a synchrocyclotron to produce a proton or ion beam having an energy level sufficient to reach a target in the patient on the
patient support;

an outer gantry on which the synchrocyclotron is mounted to enable the synchrocyclotron to move through a range of positions
around the patient on the patient support; and

an inner gantry comprising a beam-focusing device to shape the proton or ion beam before the target;
wherein the synchrocyclotron (i) comprises a magnet that produces a magnetic field strength of up to 20 Tesla, (ii) is configured
to produce, for delivery to a patient, a beam of charged particles having an energy level of at least 150 MeV, and (iii) has
a weight less than 30 Tons.

US Pat. No. 9,661,736

SCANNING SYSTEM FOR A PARTICLE THERAPY SYSTEM

Mevion Medical Systems, I...

1. A particle therapy system comprising:
a particle accelerator to output a beam comprised of pulses of charged particles, the pulses being synchronized to radio frequency
(RF) cycles of the particle accelerator; and

a scanning system to scan the beam across at least part of an irradiation target, the scanning system comprising:
a scanning magnet to move the beam during scanning, where a position of the beam corresponds to a current of the scanning
magnet; and

a control system (i) to control the current in order to produce uninterrupted movement of the beam across at least part of
an irradiation target to deliver doses of the charged particles that are based on the pulses, the uninterrupted movement being
independent of the RF cycles of the particle accelerator, (ii) for positions at which the particle beam delivers dose in synchronism
with the RF cycles, to store information identifying a location and an amount of dose delivered, (iii) to compare a cumulative
dose delivered at each position to a target cumulative dose, and (iv) if the cumulative dose does not match the target cumulative
dose at specific positions, to control the current in order to move the beam so as to deliver additional dose to the specific
positions.

US Pat. No. 9,706,636

ADJUSTING ENERGY OF A PARTICLE BEAM

Mevion Medical Systems, I...

13. A system comprising:
a magnet comprising one or more coils to conduct current to generate a magnetic field, the magnetic field to affect output
of radiation to a target, the magnet being configured for movement relative to the target; and

one or more actuators that are controllable to move the one or more coils physically based on the movement of the magnet.

US Pat. No. 9,730,308

PARTICLE ACCELERATOR THAT PRODUCES CHARGED PARTICLES HAVING VARIABLE ENERGIES

Mevion Medical Systems, I...

1. A synchrocyclotron comprising:
a voltage source to provide a radio frequency (RF) voltage to a cavity to accelerate particles from a particle source;
one or more coils to pass electrical current having one of multiple values and to generate a magnetic field in the cavity
corresponding to the electrical current, the magnetic field for causing the particles to move orbitally within the cavity
at an energy that corresponds to the electrical current, the magnetic field being at least 4 Tesla;

magnetic pole pieces at least partly defining the cavity, the magnetic pole pieces comprising ferromagnetic material; and
an extraction channel to receive the particles from the cavity and to output the particles, the particles that are output
having an energy that corresponds to the electrical current;

wherein the synchrocyclotron is configured to enable setting of the electrical current to one of the multiple values, each
of the multiple values corresponding to a different energy at which particles are output from the cavity;

wherein the energy of the particles that are output from the cavity is in a range that is between about 100 MeV and about
300 MeV; and

wherein the voltage source is configured to sweep the RF voltage over different frequency ranges, each different frequency
range corresponding to a different energy at which particles are output from the cavity.

US Pat. No. 9,950,194

PATIENT POSITIONING SYSTEM

Mevion Medical Systems, I...

1. A method of positioning a patient for treatment using a particle therapy system, comprising:associating fiducials with the patient;
using a first imaging system located at an imaging position to capture a first image of the fiducials and of an irradiation target while the patient is on a treatment couch, the imaging position being in a treatment room where treatment using the particle therapy system is to be performed;
moving the treatment couch while the patient is on the treatment couch from the imaging position toward a treatment position at which the treatment using the particle therapy system is to be performed, the treatment position being different from the imaging position and being in the treatment room;
following movement of the treatment couch, using a second imaging system to capture a second image of the fiducials in the treatment room while the patient is on the treatment couch;
determining locations of the fiducials in the treatment room based on both the first image and the second image;
determining a location of the irradiation target relative to the particle therapy system based on locations of the fiducials in the treatment room and in the first image; and
moving the treatment couch into the treatment position in the treatment room based on the location of the irradiation target;
wherein the patient remains on the treatment couch during capturing the first image, through moving the treatment couch toward the treatment position, through capturing the second image, and through moving the treatment couch into the treatment position.

US Pat. No. 9,925,395

INNER GANTRY

Mevion Medical Systems, I...

1. A system comprising:a patient support to hold a patient;
a particle accelerator to produce a proton or ion beam having an energy level sufficient to reach a target in the patient;
a gantry on which the particle accelerator is mounted to move the particle accelerator through a range of positions around the patient on the patient support;
scanning elements that act on the proton or ion beam, the scanning elements being between the patient and a location at which the proton or ion beam exits the particle accelerator; and
an aperture between the particle accelerator and the patient, the aperture being configurable to alter the proton or ion beam prior to the proton or ion beam reaching the target, the aperture being movable in multiple dimensions relative to the patient.

US Pat. No. 9,913,995

PARTICLE BEAM SCANNING

Mevion Medical Systems, I...

1. A particle therapy system comprising:
a synchrocyclotron to output a particle beam;
a magnet to affect a direction of the particle beam to scan the particle beam across at least part of an irradiation target;
and

scattering material that is configurable to change a spot size of the particle beam prior to the particle beam reaching the
irradiation target;

wherein scanning performed by the particle therapy system is spot scanning;
wherein the spot size is changeable from scan-location to scan-location; and
wherein the spot size is changeable on a time scale on the order of tenths of a second.

US Pat. No. 9,962,560

COLLIMATOR AND ENERGY DEGRADER

Mevion Medical Systems, I...

1. A particle therapy system comprising:a particle accelerator to output a particle beam;
a scanning system for the particle accelerator to scan the particle beam across at least part of an irradiation target in a patient, the scanning system being configured to scan the particle beam in at least two dimensions across the at least part of the irradiation target; and
a collimator comprising multiple elements that are controllable to move in the at least two dimensions relative to the particle beam during scanning to track motion of the particle beam as the particle beam is scanned across the at least part of the irradiation target, the multiple elements comprising a material that inhibits transmission of the particle beam, each of the multiple elements comprising fingers that are extendible and retractable in one of the two dimensions to define an edge of the collimator that is movable between a first part of the particle beam and the patient to prevent the first part of the particle beam from reaching the patient while allowing a second part of the particle beam to reach the at least part of the irradiation target.

US Pat. No. 10,213,620

PARTICLE BEAM SCANNING

Mevion Medical Systems, I...

1. A particle therapy system comprising:a synchrocyclotron to output a particle beam;
a magnet to affect a direction of the particle beam to scan the particle beam across at least part of an irradiation target; and
scattering material that is configurable to change a spot size of the particle beam prior to the particle beam reaching the irradiation target;
wherein scanning performed by the particle therapy system is spot scanning;
wherein the spot size is changeable from scan-location to scan-location; and
wherein the spot size is changeable on a time scale on the order of tenths of a second.

US Pat. No. 10,368,429

MAGNETIC FIELD REGENERATOR

Mevion Medical Systems, I...

1. A particle accelerator comprising:a voltage source to provide a radio frequency (RF) voltage to a cavity to accelerate particles within the cavity, the cavity having a magnetic field causing the particles to move orbitally within the cavity;
an extraction channel to receive the particles from the cavity and to output the received particles from the cavity; and
a regenerator to provide a magnetic field change within the cavity to thereby change orbits of particles within the cavity so that, eventually, the particles output to the extraction channel, the regenerator comprising an edge comprising a non-orthogonal intersection of two faces;
wherein the magnetic field in a center of the cavity is at least 6 Tesla.

US Pat. No. 10,254,739

COIL POSITIONING SYSTEM

Mevion Medical Systems, I...

1. A system comprising:a magnet comprising one or more coils to conduct current to generate a magnetic field, the magnetic field to affect output of radiation to a target; and
one or more actuators, an actuator among the one or more actuators being at least part of a physical coupling to the one or more coils, the actuator being controllable to move the one or more coils via the physical coupling based on movement of the magnet.

US Pat. No. 10,279,199

INNER GANTRY

Mevion Medical Systems, I...

1. A system comprising:a patient support to hold a patient;
a synchrocyclotron to produce a proton or ion beam having an energy level sufficient to reach a target in the patient, the energy level being at least 150 MeV;
a gantry on which the synchrocyclotron is mounted to move the synchrocyclotron through a range of positions around the patient on the patient support; and
scanning elements that act on the proton or ion beam output from the synchrocyclotron, the scanning elements being between the patient and a location at which the proton or ion beam exits the synchrocyclotron.

US Pat. No. 10,258,810

PARTICLE BEAM SCANNING

Mevion Medical Systems, I...

1. A particle therapy system comprising:a synchrocyclotron to output a particle beam;
a magnet to affect a direction of the particle beam to scan the particle beam across at least part of an irradiation target; and
scattering material that is configurable to change a spot size of the particle beam prior to the particle beam reaching the irradiation target;
wherein scanning performed by the particle therapy system is spot scanning;
wherein the spot size is changeable from scan-location to scan-location; and
wherein the spot size is changeable on a time scale on the order of tenths of a second.