3D X-Ray Beam Metrology
CyberKnife Quality Assurance
Quality Assurance FAQs
XRV2020 2D Beam Profiler

IBAC System Features

-IRIS aperture and X-ray beam width metrology

-Real-time beam profile capture

-Beam diameter accuracy to .05 mm

-Dose duration accuracy to 50 ms

-3D beam profile viewing and measurement

-Aperture width accuracy to .05 mm

-BeamWorks automated measurements

-Advanced statistical analysis via spreadsheet macros

-Archives all data for trend analysis

-Detached Iris operation for 80 cm SAD measurements

-Setup and training included

3D Beam Spot Viewing

IBAC Camera Module

The IRIS Beam Aperture Caliper (IBAC) is the newest member of the XRV family of X-ray beam metrology systems. Combining precision metrology with high-energy radiation detection, the IBAC is a completely electronic alternative to film-based measurement.

The IBAC mounts directly to the CyberKnife robot and performs a variety of measurements at the exit point of the X-ray beam from the IRIS collimator. Beam profiles and aperture widths can be obtained with a single mouse click, and automation scripts can be used to record changes in the beam shape and intensity. Beam and aperture images are archived for later review and measurements are easily integrated into spreadsheet programs for trend analysis and report generation.

The IRIS aperture and beam measurements are accurate to .05 mm and repeatability is typically .02 mm. The camera module comes with a 3 to 30 meter (100 feet maximum) USB cable system so the operator can be located safely away from the treatment room.

IBAC Operation

The XRV IBAC system uses a plug-in scintillator to turn invisible X-ray beam fluence into visible light that can be measured with the highly sensitive CCD camera and sophisticated metrology software. An access panel in the mounting column allows the scintillator module to be removed for direct viewing of the IRIS aperture. In this mode, the aperture is illuminated by LEDs located in the column.

The BeamWorks software application is used to acquire, analyze, and archive IBAC images. Precision metrology algorithms measure the beam spot and aperture widths multiple times to verify accuracy. Beam diameters can be measured at any vertical slice of the beam for easy penumbra calculations. Spreadsheet macros are provided for statistical analysis of the captured data. Measurements can be made from the GUI or customized with a powerful scripting environment.

Shown below is the beam caliper mode of the IBAC. X-ray fluence (blue) illuminates the scintillator and the visible representation of the beam (yellow) proceeds to the camera for measurement.

The aperture gauge mode of the IBAC illuminates the lower collimator of the IRIS with LED light (blue) and measures the aperture with .05 mm resolution.

Thank you for viewing our website.

You are visitor #

IBAC Specifications:


Beam Diameter: +-.05 mm
Repeatability: +-.02 mm (typical)
Aperture Width: +-.05 mm
Repeatability: +-.02 mm (typical)

Optical System:1

Resolution:1280 x 960 pixels binned to 640x480 pixels
Capture Rate:20 frames/sec (typical)
Lens MTF:Megapixel resolution
Camera Interface:USB

Optional Camera Shielding:2

Camera Top:12.7 mm lead alloy
Camera Sides:12.7 mm lead alloy
CCD Lifetime:~1,500 beam hours

Camera Module Physical:

H x W x D:31.75 x 15.25 x 64.75 cm
Weight:9.1 kg (20 lbs)
Enclosure Material:Aluminum and stainless steel


Capture Trigger:GUI, Script, I/O, or Network watch-file

Computer Components:

Computer:HP laptop or selectable desktop configuration
Misc:USB to Cat-5 extension cable
Pelican case
Windows 7
USB Dongle License


Electrical Power:110 - 220V, 2 or 4A
9V battery
Environment:5 to 30 degrees C
90% humidity, no condensation
Minimal vibration


1. Contact us for higher camera resolutions.
2. Contact us for custom shielding requirements. The camera may be replaced for a service fee when the number of weak pixels begins to impact measurement accuracy. This time duration varies on use but is estimated to be approximately 3 years.

CyberKnife and IRIS are registered trademarks of Accuray Incorporated.