Fraunhofer IPA's new needle positioning robot
"Robots help position interventional needles
- Finding the ideal position for interventional needles – as used in biopsies, for instance – is a difficult and time-consuming process.
- This can now be performed automatically, using a robotic arm to place a needle guide for the doctor at the optimal insertion point.
- With robotic assistance, doctors need five minutes to position the needle, as opposed to 30 minutes with conventional techniques.
- The solution will be shown at the MEDICA trade fair in Düsseldorf from November 14 to 17, 2016 (Hall 10, Booth G05).
Combining robot precision and doctors’ expertise Soon, precisely positioning needles will become faster thanks to a robotic arm that researchers from the Fraunhofer Institute for Manufacturing Engineering and Automation IPA’s Project group for Automation in Medicine and Biotechnology PAMB and the Fraunhofer Institute for Medical Image Computing MEVIS have modi fied specifically for this purpose. “Whereas humans struggle to position this sort of needle, it’s hard to beat a robot designed for the purpose,” says Andreas Rothfuss, a researcher at the PAMB. “Our system removes burdens for doctors while leaving them in control.” In other words, the robot does what it does best – locating the right path and positioning the needle guide so that there is no risk of hitting or injuring either doctor or patient. Thereafter, the doctor again takes command and inserts the needle into the tissue. “A human needs 30 minutes to position the needle, but with robot assistance this is cut down to five minutes at most,” says Rothfuss.
To begin the procedure, the doctor begins by performing a computed tomography scan of the patient. This time, however, the robot arm accompanies the scan using a cali- bration tool to determine the ideal position to target a specific point in the image. Software from Fraunhofer MEVIS analyzes the image and supports the doctor in placing the virtual needle by displaying the needle in the image. If, instead of a biopsy, the doctor is administering treatment – seeking to destroy a tumor by applying heat, for instance – the software simulates how the heat will spread through the tissue. The last step is to determine the number of needles and their positions required to kill off the entire tumor. Thereafter, the robot arm’s calibration tool is replaced with a needle guide. The robot transports the guide to the calculated position and places it on the skin at the correct angle. However, it does not insert the needle itself: this is left to the doctor, who pushes the needle into the tissue step by step through the needle guide held in place by the robot. Less radiation exposure for doctor and patient To ensure that the needle is in the planned position, doctors take X-rays as part of the standard procedure as they insert the needle into the tissue. Here, too, the robot offers several advantages. In conventional needle insertion, doctors hold the needle in place manually, obscuring a part of the X-ray. This also exposes doctors’ hands to radiation each time a monitoring image is taken. Now, the robot, impervious to radiation, can hold the needle in place with its needle guide. There is also a signifi-cant reduction in the patient’s radiation exposure – the doctor inserts the needle through the guide, eliminating needle slippage. As a result, the number of monitoring X-rays is greatly reduced.
Researchers hope that the system could reach the market in around three years."