A study of tool pattern design for calcified-atherosclerotic-plaque removal robot

Atherosclerosis is a major cardiovascular disease involving accumulations of lipids, white blood cells, and other materials on the inside of artery walls. Rotational atherectomy (RA) is a technique in which a small grinder is inserted into the coronary arteries to ablate plaque and increase blood flow to the heart. High-speed rotational atherectomy, when performed with an ablating grinder to remove the plaque, produces much better results in the treatment of calcified plaque than other methods. The Rotablator, commercial rotational atherectomy device, and other RA tools were developed and used for calcified plaque removal. However, the fabrication processes of the tools are complex and require considerable expenses and time. In this research, a new rotational ablation tool and its fabrication method for calcified atherosclerotic plaque removal is presented. It relies on surface modification to achieve the required surface roughness. Four different types of tool pattern were suggested and the surface of the tools were modified using Nd:YAG laser beam engraving. The ablation experiment was performed on hydroxyapatite/polylactide (HA/PLA) composite which has an elastic modulus similar to that of calcified plaque. The tool performance and reliability were evaluated by measuring the ablation force exerted.