JULIE LEGRAND WINS BELGIAN PHD AWARD

RESEARCH IN FOCUS

He who damages his nose damages his face. In modern surgery, this old saying is taken very seriously. Consequently, operations on sinuses are consistently performed through minimally invasive surgery. As a PhD student, Julie Legrand developed a new technique to perform procedures even in the most difficult attainable areas. For her pioneering work, she was awarded the Belgian PhD Award from the National Committee for Theoretical & Applied Mechanics.

On 28 May 2021, Julie successfully defended her PhD thesis ‘Single-handed, flexible, stearable instruments for constrained workspace surgery’ at the Faculty of Engineering Technology in Leuven. Given her study background -Julie is a Master of Mechanical Engineering from UCL- one would have expected her PhD rather at the sister Faculty of Engineering Science. An interesting vacancy in Prof. Manu Vander Poorten’s Robotics, Automation & Mechatronics research group (Group T Campus) made Julie decide otherwise.

Maxillary sinus

“If you take minimally invasive to the extreme, it’s called ‘Natural Orifice Transluminal Endoscope Surgery’,” Julie explains. “In this, surgery is performed through the body’s natural orifices. That seems obvious, but in practice you run into the complexity of human anatomy. This means that the surgeon’s working space is usually very limited. On top of that, every person is different, so fixed standard equipment using rigid instruments almost always creates the need to cut away extra tissue.”

In her research, Julie focused on the maxillary sinus or jawbone cavity. This is located near the small molars and is difficult to access with endoscopic sinus surgery. Julie’s assignment was to develop a new, flexible instrument for this type of procedure so that no tissue needs to be removed. An additional requirement was that the surgeon must be able to operate the device with one hand, in order to be able to do other supportive work.

Actuator

“The first phase of my research consisted in a statistical analysis of a large amount of images and scans of the jawbone cavity,” Julie explains. “Since it is not economically feasible to make a customised instrument for every patient, it came down to finding a greatest common denominator. I then designed an add-on that could be attached to an existing passive endoscope.

The next step was to develop a miniature pneumatic actuator that could serve as an artificial muscle. This allowed the instrument to be made as compact as possible. Via an algorithm, hysteresis or unwanted position differences can be compensated without having to deploy large sensors. Another algorithm ensures that the end of the flexible instrument can react smoothly to an action by the surgeon.”

Unique

Add all these components together and you obtain a “onehanded, flexible, controllable instrument for limited workspace surgery”. According to Julie, this is the thinnest flexible endoscope for maxillary sinus surgery designed to date. Two surgeons tried out the instrument and confirmed its added value.

Can Julie’s innovation be used in other procedures as well? The answer is positive. “In the whole range of nose, throat and ear, the possibilities are numerous, even in brain surgery. Knee surgery that is already minimally invasive can be perfected even more.”

Julie Legrand

©Julie Feyaerts

Postdoc

Julie is currently a postdoc at VU Brussels. There, she is working on the development of soft robots for use in prosthetics or in moving fragile objects. She is also supervisor of two PhDs and fulfils a limited teaching assignment in the interuniversity Biomechanics course. An academic career seems right up her alley. The Belgian Best PhD Award may yet prove to be of golden service in this regard”.

Yves Persoons