Building block for better radiotherapy

Radiotherapy is becoming an increasingly high-tech solution. The more precise the treatment, the greater its success. One important aspect is the patient positioner.

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The patient positioner is used to position people who are undergoing radiation treatment. It accurately corrects the smallest movements, which can be caused, for example, by the patient breathing. This improves the quality of the treatment. (Picture: DEKRA)

A patient on a stretcher floats almost silently through the room, which has wood paneling, dimmed lights, the image of a sunrise projected on the wall, and meditation music like in a spa. Relaxation is important, because radiotherapy is a matter of life and death. Firstly an innovative rotating X-ray system mounted directly on the patient’s stretcher takes very high-quality three dimensional images to define the exact position of the tumor. An attractive-looking robot arm, which reaches down from the ceiling, now takes over. It transports the patient to the beam of radiation and the individual treatment program can begin.

The positioning system has seven independent directions of movement. A visual monitoring system checks the position of the stretcher 500 times per second and corrects it to an accuracy of half a millimeter in real time, if the patient and the stretcher move unexpectedly, for example. The treatment lasts for five to ten minutes. A huge amount of work carried out by MedAustron in the Austrian town of Wiener Neustadt lies behind this system. The completely new treatment and research center for ion therapy, which was built in a record time of only 18 months starting in 2011, even has its own particle accelerator and uses innovative technology that was previously unavailable.

This includes, for example, the Exacure system developed by BEC, MedAustron’s partner based in the German town of Reutlingen, which consists of the robot arm, among other things. Matthias Buck founded BEC in 2003 while he was still a student. It is a genuine start-up that until recently was based in another company’s workshop, but has now moved to an industrial park. Projects run by the company enabled it to develop a relationship with Kuka, a wellknown manufacturer of industrial robots, and with Siemens. The BEC team worked on robotic solutions in the field of radiotherapy on behalf of the Munich-based technology group. BEC specialized in developing software and hardware that opened up new applications for robots. When Siemens then decided to move out of the treatment field, BEC exploited the resulting gap in the market. The team of 28 engineers and scientists at BEC covers a wide range of diff erent technologies with one specific objective: to improve humanrobot cooperation.

As Buck explains: “The major challenge in this area is to meet the electrical and mechanical safety requirements that arise when people and machines work closely together.” BEC is now certified in accordance with ISO 13485 to manufacture medical products and has sites in Atlanta in the USA and Montpellier in France. But the patient positioner is not the only product in BEC’s portfolio. It also produces robotic movement simulators, which can be used in aviation training. The pilot sits in an enclosed capsule and flights are projected onto the internal walls. The robot arm, which has the gondola mounted on its hand, can perform a wide range of movements, including centrifugal acceleration, and offers the option of putting pilots into extreme situations, including rapid rolls, for example.

BEC’s system is currently the only one in the world that allows for human interactive actions on the basis of the kinematics of a robot with six axes and a payload of up to one ton. Movement simulators are also relevant for the agricultural industry. In a project involving the University of Hohenheim, controls will be developed for a tractor that can be used for different purposes on a wide variety of terrains to reduce the complexity of the various tasks and improve the workflows.

Without false modesty, BEC is one step ahead when it comes to one of the fundamental principles of Industry 4.0, a concept that fi rst emerged in 2011 at the Hanover Fair. One of the company’s main aims is to improve human-to-machine communication. As Buck explains with a wink: “What is needed for Industry 4.0 is already available to order from our catalog.”

Medical products must meet extremely high safety standards

BEC has already installed three patient positioners for MedAustron and a fourth is due to follow. They are actually industrial robots, similar to the thousands that are in use on production lines throughout the world. But in this case they are classified as medical products and have to comply with quite different safety standards. Karsten Dankmeyer, head of the medical product testing team at DEKRA Testing and Certification GmbH, has created a comprehensive set of testing documentation for mdc medical device certification GmbH in Stuttgart, the notified body which grants certification under the terms of EU directives. Dankmeyer has been testing “active” medical devices in Stuttgart and Dresden since 2011 with his team of three employees. However, he did not bring the patient positioner, which weighs several tons, into the lab for testing, but instead traveled to Reutlingen at regular intervals between February and August 2015 and finally submitted around 200 pages of documentation covering the hardware and software.

“The important issues were the electrical safety of the entire machine, its mechanical load-bearing capacity, and the overall risk management.” The manufacturers speeded up the networking process, as Dankmeyer explains: “They no longer offer individual devices, but complete system solutions. BEC is a good example of this trend and the patient positioner is definitely one of the high points of my career as a test engineer.” MedAustron is still in the test phase. “The challenges are the interfaces to the various systems,” says Buck. But the machines will come into operation on schedule in 2016. The team at MedAustron is expecting to treat around 1.400 patients each year. Many cancer sufferers will benefit in the long term from this special ion beam therapy, which promises a cure for previously untreatable cases and a new ray of hope.

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