The American Cancer Society estimates that around one in nine men will be diagnosed with prostate cancer at some point in their lives. A robotic system for use inside MRI scanners enables highly accurate prostate biopsies. The system incorporates pneumatic drives and controllers.
Prostate cancer is one of the most common cancers in men. The American Cancer Society estimates that there were around 192,000 new cases in the USA in the last year alone. As a rule, the chances of recovery increase if the cancer is detected at an early stage. In these cases, treatment is more effective, there are fewer side effects and the costs are lower.
Currently, surgeons often rely on ultrasound images when conducting prostate biopsies, but these images have a relatively low resolution. The urologists therefore take randomised systematic biopsies consisting of 12 to 16 samples taken from different portions of the prostate to locate the tumour as best as possible.
Accurate location with the remote controlled manipulator (RCM)
The remote controlled manipulator (RCM) robotic system from the Dutch company Soteria Medical BV makes location and sampling much easier. The procedure is performed inside a magnetic resonance imaging (MRI) scanner, which produces much more accurate images than ultrasound. The software system is also an important part of the RCM. It compares the current images of the affected area against earlier diagnostic scans.
During the operation, five motors move the needle to the exact location. The surgeon then uses the MRI images to insert the needle safely and accurately into the prostate to take tissue samples for further investigation.
No metal and minimal space – the design challenges
The robotic system cannot contain any metal, as this would interfere with the MRI scanner. It also needs to be compact enough to fit inside the MRI scanner with the patient. The entire RCM is therefore made from high-quality, MRI-compatible plastics.
The motors are pneumatic stepper motors made of plastic, controlled by a Festo valve terminal type MPA. The robotic probe is also connected to the control unit by pneumatic tubing. This enables space-saving installation of the controller in the MRI control room.
Video: The RCM robot system in use