Manual Collimator — Frequently Asked Questions

We've listed answers to some of our most common Manual collimator questions for your convenience.

What does a collimator do?

An integral component to successful X-ray performance, the collimator touches all aspects of radiology. Basic collimator operation consists of controlling the shape of an X-ray beam through a series of fixed and variable barriers. These barriers are designed to provide a limited focus and project a useful beam onto a specific diagnostic area. Fixed barrier position, and shape and operation of variable barriers or “shutters” determine the performance, ease of use and ultimate reliability of the particular collimator design.

What are the limitations of current collimator designs?

The first commercially available collimator was introduced in the early 1960's. Although several revisions have afforded improved accuracy and performance since their inception, most collimators are still comprised of nearly three hundred components. Overly complex, traditional designs are inherently prone to maintenance and accuracy problems due to the shear volume of interrelated parts. In particular, many mechanical tolerances can become loose over time. Rigidly structured to meet historically accepted design parameters, most current collimator designs have not changed in over fifteen years.

How do collimators affect imaging performance and reliability?

Radiology administrators share many common goals in implementing effective radiology programs. Maintaining X-ray accuracy, reliability and ease of use are all important factors in achieving effective patient throughput. Collimators are an important component in this process. New choices in simplified collimator designs allow administrators worldwide to help contain the high costs associated with imaging system maintenance and downtime. Both existing and planned radiology systems can benefit from this new simplified technology to offset the often hidden factors associated with radiology cost savings — long term reliability and serviceability.

Is accuracy an issue in collimator design and performance?

Imaging specialists have always expected accurate performance from their X-ray equipment. However, most administrators realize that reliability and serviceability are the key to maintaining that performance over time. In an attempt to control many of the accuracy problems historically encountered with the use of collimators, the FDA mandated stringent Positive Beam Limitation (PBL) guidelines. The original goal of PBL was to create a consistent standard for accuracy in collimator operation. Achieving only limited acceptance, PBL was eventually dropped due to a unified objection from the radiology community. Common complaints stemmed from the complexity, reliability and service expenses related to maintaining the PBL collimator system.

With the demise of PBL, many collimator users must depend on cumbersome and time consuming manual operation in order to provide a level of accuracy necessary to ensure proper X-ray performance. Most manufacturers now offer complex manual collimators that were originally designed to be PBL automatic.

What is the advantage of a simplified design?

Anything that simplifies the complexities of imaging equipment will ultimately reduce the probability of mechanical breakdowns and associated costs of repair and downtime. Often, it's what's not inside that counts. Most collimators are too complicated, contain too many components, and are too difficult to service. There is much to gain with a simplified design.

What sets your design apart from other currently available models?

Huestis Medical offers a uniquely simple approach to collimator design. Highly engineered, our collimators feature a simplified, modular core assembly. Our modular approach and detailed engineering eliminates over eighty-percent of the discrete parts found in other collimator designs. This significant reduction in parts translates into measurable gains in long term reliability and performance.

Why is your collimator blade design patented?

Perpendicular, flat collimator blades increase reliability and facilitate quick servicing with simple, modular construction. Our patented blade design allows precise control without the complexity of existing designs. Completely modular, the entire collimator and blade assembly can be disassembled in minutes. We feel that these proprietary design features are critical to delivering accurate and reliable collimator performance.

Are there serviceability issues that should be considered?

Required maintenance items are often overlooked in collimator design. Many models require the entire cover to be removed for routine mirror adjustments. Huestis Medical's design allows for quick field light adjustments with an integrated access port for mirror adjustment. Lightbulb adjustment is also facilitated with an easily removed access panel.

Why do you use thumb slides instead of knobs on your manual model?

Directly coupled shutter drives eliminate mechanism and gear backlash common to rotary knob designs for improved accuracy and ease of use. By eliminating rotary adjustments, the collimator controls can be directly linked to the shutters in a direct “push-pull” motion. Going direct means less pieces, less motion and less wear and tear. This direct coupling eventually contributes to overall accuracy and reliability of collimator blade positioning.

The use of thumb slides in our manual models vs. rotary knobs in other designs also allows true one-handed operation. Both thumb slides can be manipulated simultaneously between the thumb and fore finger for quick, easy adjustments.

What does your Selectable model offer?

Huestis Medical's new Selectable™ collimator provides automatic sizing without the complexity of traditional PBL systems. It allows technicians to easily select film size and S.I.D. directly from the front panel of the collimator. It provides the accuracy, convenience and throughput of an automatic PBL collimator at a fraction of the total cost of a PBL system. Uniquely simple, it alleviates complex systems traditionally required to accept, size and feed information from the Bucky to the collimator. It features our patented modular, flat collimator blades, controlled with directly coupled motor drives. The state of the art micro-controller electronics are fully integrated and self-contained in the collimator head eliminating the historical problems associated with complex remote electronic logic and cabling.