Ongoing research projects
Ongoing research projects in iMMC (September 2020)
This a short description of research projects which are presently under progress in iMMC.
Hereunder, you may select one research direction or choose to apply another filter:
List of projects related to: Biomedical engineering
|Designing the next generation of ankle prostheses: towards efficient and lightweight designs|
Researcher: François Heremans
Supervisor(s): Renaud Ronsse, Bruno Dehez
Over the last decade, active lower-limb prostheses demonstrated their ability to restore a physiological gait for transfemoral amputees by supplying the required positive energy balance during daily life locomotion activities.
However, the added-value of such devices is significantly impacted by their limited energetic autonomy, excessive weight and cost preventing their full appropriation by the users. There is thus a strong incentive to produce active yet affordable, lightweight and energy efficient devices.
To address these issues, we are developing the ELSA (Efficient Lockable Spring Ankle) prosthesis embedding both a lockable parallel spring and a series elastic actuator, tailored to the walking dynamics of a sound ankle. The first contribution concerns the developement of a bio-inspired, lightweight and stiffness adjustable parallel spring, comprising an energy efficient ratchet and pawl mechanism with servo actuation. The second contribution is the addition of a complementary rope-driven series elastic actuator to generate the active push-off.
Our new system produces a sound ankle torque pattern during flat ground walking. Up to 50% of the peak torque is generated passively at a negligible energetic cost (0.1 J/stride). By design, the total system is lightweight (1.2 kg) and low cost.
Researcher: François Henrotte
Supervisor(s): Jean-François Remacle
completed his Engineering Degree in 1991 and his PhD in 2000, both at the University of Liège in Belgium. He then spent 4 years at the Katholieke Universiteit Leuven and 6 years at the Institut für Elektrische Maschinen in Aachen, Germany, and is now with the UCL and the ULiège. Developer in the open-source packages Gmsh, GetDP and Onelab, he has also developed skills in the multiphysics simulation of electrical machines and drives. His main interests are finite element analysis, numerical modeling, electromechanical coupling, material properties (hysteresis, iron losses, superconductors), applied mathematics (differential geometry, algebraic topology, convex analysis, dual analysis, energy methods), multiscale methods, sensitivity and optimization.
|AVATAR² - Aortic VAlve TransApically Resected and Replaced|
Researcher: Xavier Bollen
Supervisor(s): Benoît Raucent
obtained his master's degree in electromechanical engineering, with specialization in mechatronics in 2011 from the Université catholique de Louvain (UCL), Belgium. In 2016, he obtained his PhD degree from the UCL.
During his thesis, under the supervision of Pr. Benoît Raucent and Pr. Parla Astarci (Cliniques universitaires Saint Luc, Brussels), he developed a new device for minimally aortic valve resection. The device was used on patients undergoing open heart surgery in order to validate its design and its functional principle.
Now he still works on the design of the device and he also works on additive manufacturing inside the IMAP department. Since September 2015, he is invited lecturer at the Polytechnic School of Louvain where he teaches technical drawing to the first year bachelor's students in engineering.
|Numerical modeling of growth and remodeling in stented arteries|
Researcher: Colin Laville
Supervisor(s): Laurent Delannay
The project aims to predict the evolution of the radial contraction of stented arteries using a continuum mechanics model, with application to bio-resorbable stent development. The capture of the stress state evolution in the artery wall requires a material model that includes:
- the modeling of the main constituents such as collagen, elastin and smooth muscles ;
- time dependent evolution such as growth and structural remodeling.
Some developed tools are also used to predict fracture in bended stainless steels.
|Optimisation of the corrosion rate of iron-based alloys for bioresorbable stent applications|
Researcher: Sarah Reuter
Supervisor(s): Pascal Jacques
The purpose of this PhD thesis is to optimise the metallic surface of iron-based alloys that are good candidates for bioresorbable stents but which corrosion properties are still insufficient. I will thus be working on these alloys by improving their surface properties, by acidifying the surface. Indeed, the corrosion products and salt compounds get deposited due to a neutral/basic environment in the close vicinity of the metal surface. These compounds act as a barrier for further corrosion. By acidifying the metallic surface, this would inhibit, or at least diminish, the deposition of these compounds. The corrosion properties of these metals will be studied by the use of electrochemical tests as well as immersion tests. The surface will be acidified by the presence of protons. This will be done by adding hydrogen in the metal. Nevertheless, the presence of hydrogen is known to weaken the metal. In order to avoid this weakening, the hydrogen will be trapped inside the steel.
This project englobes different disciplines and is made alive thanks to close collaboration with different entities of the UCL.
|Bio-inspired neural control for a new generation of transfemoral prostheses|
Researcher: Sophie Heins
Supervisor(s): Renaud Ronsse
Designing mechanical devices to restore natural locomotion for transfemoral amputees still raises many challenges. One of them is the development of an efficient control strategy for the prosthesis active joints, with the objective of making it flexible and intuitive to use. The aim of the PhD thesis is to develop a bio-inspired controller for a new generation of transfemoral prostheses, the CYBERLEGs prosthesis, for level-ground walking and for other locomotion tasks. The controller is based on three fundamental neuro-mechanical principles that were observed in healthy humans: motor primitives, local reflexes and postural support. This work also involves the investigation of the optimal combination of these bio-inspired strategies.
|Locomotion assistance through active motor primitives|
Researcher: Henri Laloyaux
Supervisor(s): Renaud Ronsse
This project is about the development and validation of a new method for assisting human locomotion with robotic devices. It will be based on so-called “motor primitives”, i.e. fundamental units of action which have been identified in the human locomotor apparatus. These primitives will be constrained to be mathematical functions with a limited number of open parameters, therefore optimizing the computational efficiency. Next, the assistance will be designed to be adaptive to the user’s particular gait and status. Finally, some primitives will be specifically developed to support the user’s balance, on top of delivering energy for assisting locomotion. These three objectives will require first theoretical developments, and then experimental validation.
|Detecting and using locomotion affordances for lower-limb prostheses by active vision|
Researcher: Ali Hussein Al-Dabbagh
Supervisor(s): Renaud Ronsse
Healthy lower-limb biomechanics reveals that active prostheses are necessary to provide amputees with human-like dynamics in various locomotion tasks like walking or stair ascending/descending. Ali’s project is about the specific challenges associated to the transition between two of these tasks, where the control parameters of the device has to be smoothly and timely adapted. Active vision is proposed to be used to augment the prosthesis with vision-based detection of possible locomotion affordances, therefore anticipating these transitions as a function of the user’s behavior.