A closed-loop artificial pancreas experienced a critical failure by administering an incorrect insulin dose to a patient. The implantable device, designed to autonomously release the hormone, began dosing below the required level. To determine the origin of the problem, the biomedical engineering team turned to non-destructive forensic analysis combining micro-computed tomography (micro-CT) and biomechanical simulations with ANSYS.
3D reconstruction and simulation of crystallization blockage 🧬
The first step was to scan the device with micro-CT, achieving a voxel resolution of 5 microns. Using Volume Graphics software, the internal channel of the outlet nozzle, barely 50 microns in diameter, was reconstructed in 3D. The volumetric reconstruction revealed an irregular solid deposit partially obstructing the duct. The blockage geometry was exported to MATLAB to process the point cloud and generate a clean mesh. This mesh was imported into ANSYS Biomechanics to simulate insulin flow through the nozzle. The CFD simulation confirmed that the deposit, identified as insulin crystals, reduced the flow rate by 40%, causing underdosing.
Lessons for implantable device design 🔧
This case demonstrates that failures in microchannels of medical devices are not always detectable by standard functional tests. The combination of micro-CT and ANSYS allows engineers to visualize internal obstructions and predict their impact on dosing. For future iterations of the artificial pancreas, it is recommended to redesign the nozzle with a larger diameter or incorporate an anti-adhesive coating to prevent crystal nucleation. Biomechanical simulation is thus consolidated as an indispensable tool for validating implant safety before clinical use.
What segmentation software do you recommend for this medical data?