4 minute read
TOWARDS ROBOT-ASSISTED RADIATION-FREE TREATMENT OF LOW BACK PAIN
Over 20% of Belgians have back pain and 80% go through a period of low back pain in their lifetime. Treatment may sometimes involve radiography and scans that expose both the patient and the doctor to harmful radiation. Ruixuan Li, affiliated with the Robot-Assisted Surgery Research Group (Group T Campus) developed a promising robot-assisted ultrasound alternative.
Ruixuan Li came to Leuven in 2016 as part of the 2+2 double degree programme of KU Leuven and SouthWest Jiaotong University in Chengdu, the capital of Sichuan province (Western China). This programme means that a student from a partner university in China -but also in Thailand, India, and Vietnamtransfers to Leuven after two years at his/her home university to complete the bachelor's programme at Group T Campus and receives a double degree. Most of these 'double bachelors' also complete their masters in Leuven.
So did Ruixuan Li. She graduated with a master's degree in Electromechanical Engineering Technology in 2020. Attracted by applied scientific research, she decides to stay in Leuven as a PhD student at Professor Emmanuel Vander Poorten's Robot-Assisted Surgery Research Group. Four years later, on 22 November 2024, she obtained her PhD in Engineering Technology on a thesis entitled 'Advanced Robotic Ultrasound Imaging for Spine Surgery'. This makes Ruixuan Li the first female international doctor of the research group.
Minimally invasive
Low back pain is one of the most common symptoms of degenerative spine disease. It affects more women than men and increases with age. "Usually, the discomfort is short-lived but when the pain becomes chronic, surgery is inevitable," Ruixuan says. "However, doctors will make every effort to use minimally invasive techniques to minimise tissue damage and speed up a quick recovery."
The treatment increasingly involves the use of minimally invasive pedicle screw placement (MIPSP). "The minimally invasive aspect involves the percutaneous placement of screws that secure vertebrae together so that the damaged and painful intervertebral disc is eliminated and pinched nerves are released," Ruixuan Li continued. "However, this method has a significant drawback.
Compared with conventional open surgery, computer-assisted techniques such as fluoroscopy lead to higher radiation exposure. The health of both the patient and the surgeon benefits from a non-radiative intraoperative solution."
Potential
The alternative that Ruixuan unpacks with is a robot-assisted ultrasound (US) system for 3D spine reconstruction. She describes it as a "non-radiation freehand ultrasound reconstruction system to assist pedicle screw placement for spine fusion surgery. Based on ultrasound images with positioning data, the spine contours are segmented by a robust deep leaning network and reconstructed in real time."
"Then, the reconstructed point clouds and surface mesh can be illustrated in 3D by a visualisation toolkit. Combining US navigation with a robotic arm ensures accurate screw placement. The robot arm autonomously positions the drill along a pre-planned trajectory and performs the drilling procedure very precisely."
Ruixuan's tests showed a success rate of 87.5%. This means that the system has great potential to be applied in intraoperative surgery as a flexible imaging technology to generate 3D structure o the anatomy of the future.
On top of that, the system promotes patient comfort, reduces healthcare costs and increases efficiency in clinical practice.
Upper back
Currently, Ruixuan Li is a postdoc at the Robot-Assisted Surgery Research Group. In a new project, she focuses on the upper part of the back.
"Unlike the static lower back, the upper spine is much more flexible. This means that ailments there are also more complex and harder to treat. During the next three years, I want to find out to what extent the technology I developed for my PhD can be used and what adjustments are needed. I already know that there will be an important role for virtual and augmented reality applications. In cardiology, these are already well established but not yet in the treatment of back pain. In three years, we will know more and better.”
-Yves Persoons
