Summary of open projects (Fall 2023)
Open positions for student projects will be listed here when available:
- Master thesis or Semester project: FEM modeling of a guidewire penetrating a blood clot
- Master thesis or Semester project: Investigation of clot extraction strategies for a robotic mechanical thrombectomy
- Master thesis or Semester Project: Comparison of balance metrics for autonomyo exoskeleton
To apply, please send an email to the responsible person for the project with your CV and briefly describe your relevant experience.
FEM modeling of a guidewire penetrating a blood clot
Category: Semester project or Master thesis
Keywords: FEM, simulation, ischemic stroke
Type: 10% theory, 60% simulation, 30% experimentation
Responsible: Evgenia Roussinova (MED 3 1115, [email protected])
Description: In the context of a project on endovascular robotics for the treatment of ischemic stroke*, we are working on a FEM simulation of arterial occlusions in order to give theoretical support to some experimental findings. Currently, we model the blood clot as a hyperelastic material. This simulation has to be extended by adding viscoelastic properties to the thrombus. Multiple simulations with different conditions (clot’s rigidity, clot’s dimensions, friction coefficient, insertion pressure) have to be performed and the results have to be analyzed.
In in-vitro experiments with synthetic blood clots we measure the interaction forces between a guidewire (a tool used in endovascular procedures) and the clot blocked in a mock-up of an artery. For now, we have only modeled in COMSOL the clot getting stuck in the artery. The next step is to model the guidewire (which has a portion made of nitinol, and a portion made of stainless steel) and then to model the guidewire penetrating the clot.
*Stroke is the 2nd leading cause of death worldwide. In ischemic stroke (the most common), a blood clot blocks an artery in the brain, thus preventing the neural tissue from getting oxygen and nutrients.
Skills: Experience with COMSOL
References: Fereidoonnezhad, Behrooz, et al. “A new compressible hyperelastic model for the multi-axial deformation of blood clot occlusions in vessels.” Biomechanics and modeling in mechanobiology vol. 20,4 (2021): 1317-1335. doi:10.1007/s10237-021-01446-4
Investigation of clot extraction strategies for a robotic mechanical thrombectomy
Category: Semester project or Master thesis
Keywords: Ischemic stroke, Clot extraction, Robotics
Type: 20% programming, 60% experimentation, 20% data analysis
Responsible: Evgenia Roussinova (MED 3 1115, [email protected])
Description: Stroke is the 2nd leading cause of death worldwide. In ischemic stroke (the most common), a blood clot blocks an artery in the brain and thus prevents the neural tissue from getting oxygen and nutrients. We are working on a neuroendovascular robotic system whose aim is to assist the doctor in performing the medical procedure of mechanical thrombectomy (“clot extraction”). Currently, the procedure is performed manually and it’s a trial-and-error process because doctors do not have information about the mechanical properties of the clot occluding the artery. In addition, humans do not have extremely precise movements, which a robot can easily provide. Therefore, in this project, we would like to test different movement profiles on occlusions with different properties (clot’s rigidity, length, etc.) and determine the best extraction strategy. The work will consist of implementing the motion profiles on a robotic device developed in the lab, performing experiments, and analyzing the collected data.
Skills: C/C++ programming, Data analysis (MATLAB or Python), Meticulousness (it’s extremely important to have patience and focus to perform the experiments diligently)
References: Soize, S et al. “Fast Stent Retrieval Improves Recanalization Rates of Thrombectomy: Experimental Study on Different Thrombi.” AJNR. American journal of neuroradiology vol. 41,6 (2020): 1049-1053. doi:10.3174/ajnr.A6559
Comparison of balance metrics for autonomyo exoskeleton
Category: Semester project or Master thesis
Keywords: Gait analysis, Balance metrics, robotics, lower-limb exoskeletons
Type: 10% theory, 30% experimentation, 60% data analysis
Responsible: Zeynep Özge Orhan (MED 3 1015, [email protected]
This project concerns the analysis of several metrics of the balance of exoskeleton users of the autonomyo lower-limb exoskeleton. Autonomyo is developed for people who have walking impairments due to muscular weakness or motor deficits. The laboratory BIOROB and the research group REHAssist have established expertise in human locomotion and lower limb exoskeletons. Autonomyo has been designed at EPFL.
Currently, Center of Pressure (CoP) based metrics are used to investigate the balance of different locomotion tasks. However, by using an external measurement system we can also investigate center of mass (CoM) based metrics as well.
This project involves different steps:
– Familiarization with existing hardware/software and firmware of the exoskeleton
– Conduct experiments with autonomyo
– Prepare functional code blocks that is synchronizing two measurement systems
– Analyze the collected data for various balance metrics
Skills:
– Experience with Matlab for data analysis
– Experience with C++
References:
Gordon, D. F., Henderson, G., & Vijayakumar, S. (2018). Effectively quantifying the performance of lower-limb exoskeletons over a range of walking conditions. Frontiers in Robotics and AI, 5. https://doi.org/10.3389/frobt.2018.00061