Abstract
This study investigated the miniature flexible grinding wheel for removal of calcified plaque in atherectomy. The grinding wheel was fabricated by nickel-diamond electroplating on a stainless steel flexible shaft. Five steps of the wheel manufacturing process were presented. The coating thickness model was derived based on Faraday's law and experimentally calibrated with the current efficiency of nickel and nickel-diamond electroplating being 97.8% and 93.4%, respectively. The grinding wheel was tested on a cardiovascular simulator with a calcified plaque surrogate made of gypsum cement. Grinding wheel motion was observed by a high-speed camera. Results showed that the plaque surrogate lumen diameter was enlarged from 2 to 3.06 mm after 10 second grinding at 80,000 rpm wheel rotational speed and further enlarged to 3.53 mm after another 10 second grinding at 120,000 rpm. An orbital motion of the grinding wheel around the vessel lumen was observed and the orbital speeds were 43,150 and 26,830 rpm at the rotational speed of 80,000 and 120,000 rpm, respectively. The proposed grinding wheel has demonstrated a sufficient efficiency for plaque removal and the potential to treat tight angulated lesions with low risk of burr entrapment and vessel perforation.