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Arterial stenosis is a high-risk disease accompanied by large amounts of calcified deposits and plaques that develop inside the vasculature. These deposits should be reduced to improve blood flow. However, current methods used to reduce stenosis require externally-controlled actuation systems resulting in limited workspace or patient risks. This results in an unexplored preference regarding the revascularization strategy for symptomatic artery stenosis. In this paper, we propose a novel internally-actuated solution: a magnetic spring-loaded rotablation catheter. The catheter is developed to achieve stenosis-debulking capabilities by actuating drill bits using two internal electromagnetic coils and a magnetic reciprocating spring-loaded shaft. The state-space model of the catheter is validated by comparing the simulation results of the magnetic fields of the internal coils with the experimental results of a fabricated prototype. Contact forces of the catheter tip are measured experimentally, resulting in a maximum axial force of 2.63 N and a torque of 5.69 mN-m. Finally, we present interventions in which the catheter is inserted to a vascular target site and demonstrate plaque-specific treatment using different detachable actuator bits. Calcified deposits are debulked and visualized via ultrasound imaging. The catheter can reduce a stenosis cross-sectional area by up to 35%, indicating the potential for the treatment of calcified lesions, which could prevent restenosis.

Master of Science Pallets are used all over the world in the field of distribution. The strength values associated with a pallet have been thoroughly investigated by many different researchers; however, the stiffness values associated with pallet joints have not. The goal of this work was to investigate the stiffnesses associated with pallets joints made with lag screws and carriage bolts. It is important to understand that different materials, fastening methods, and design considerations can have a huge impact on the stiffness of the joint. This paper will discuss the various tests that were used to measure the actual stiffness of pallet joints and the results of those tests. Afterwards, the researchers detail their attempt to predict the stiffness using an equation created from the actual test data. Finally, by understanding the effects of these various factors, better pallet designs can be created that are both safer and stronger using the investigated alternative fasteners.