QUASAR™ Respiratory Motion Phantom (PRESP)

Respiratory motion QA


Rapidly emerging technologies, such as IGRT and respiratory gating, have led to significant advances in patient treatment.

Gating is one of the many technologies that track tumour motion during the respiratory cycle. To ensure accuracy, respiratory gating also uses QA to simulate the breathing of a patient and account for respiratory motion during radiation delivery. Modus QA has developed a line of programmable QUASAR™ Respiratory Motion QA devices that respond to this growing field in radiotherapy.

Simulate Patient Breathing

The QUASAR™ Respiratory Motion Phantom (PRESP) is a programmable state-of-the-art breathing simulator for conducting quality assurance testing on radiotherapy systems and using a personal computer to communicate with the QUASAR™ Respiratory Motion Phantom, the software application downloads patient respiratory waveforms to the phantom, simulating the breathing function.

Used for regularly scheduled testing, commissioning new systems and upgrades, and testing repairs, the Respiratory Motion Phantom is designed to move cylindrical inserts in the superior/inferior direction within a body-shaped oval with varying speed and amplitude.

Several different moving inserts are available for a variety of applications. Insert motion is linked to a moving Chest Wall Platform designed to carry a respiratory tracking device.

The QUASAR™ Respiratory Motion Phantom is designed to work with different therapy delivery systems and is compatible with kV and MV CT imagers.


  • Communicate with phantom through local area network
  • Requires no additional programming or customization
  • Ability to rotate inserts as they translate to create 3D motion
  • Compatible with third-party waveforms including; .VXP, .CSV, .TXT, .DCM, .LOG, .DAF, .IMA
  • Install the software on an unlimited number of computers at all official sites

Motion Inserts

Increase QA Test Capabilities with Interchangeable Inserts

With additional inserts from Modus QA, the QUASAR™ Respiratory Motion Phantom is capable of performing a wide range of IGRT and Gated QA applications including;

  • Planning system QA
  • Dose distribution measurement for both neutral density and lung density material
  • 4D CT imaging
  • 4D PET CT imaging

Contact OSL to find out more about the full range of inserts.

Custom inserts are available upon request for various FARMER ion chambers, MOSFETs, diodes, and other point dose measurement devices.


Visit the Modus QA website here for the full technical specification.

Patient-Specific Motion QA Software

Import Waveforms

Included Motion QA Software allows you to import patient-specific waveforms from a number of respiratory gating machines including Varian Real-time Position Management™ (RPM), Anzai, Cyberknife, Philips, Respisens, and Siemens.

Wave Editor

Conveniently edit waveforms using a wide range of functions include adjusting the amplitude, stretching or compressing the timeline and filtering out high-frequency noise, low-frequency drift and cardiac signals.

Creation Wizard

Quickly create custom or unique waveforms using the built-in waveform creation wizard or by importing a tab-delimited file created in a spreadsheet program or an ASCII text formatter.

Product video demonstration

TrueBeam Gated SBRT with Advanced Imaging

Watch how the QUASAR™ Respiratory Motion Phantom works with TrueBeam using a Split Cedar Insert with 3 gold seeds placed inside the tumour.

Product video demonstration

QUASAR Respiratory Motion Phantom

An overview of the QUASAR™ Respiratory Motion Phantom performance and controls.

Product video demonstration

QUASAR™ Rotation Stage

A step-by-step tutorial on how to add the rotation stage to the QUASAR™ Respiratory Motion Phantom for non-linear 3D motion.