Experimental Investigation of the Grinding Wheel Dynamics in Atherectomy

This research studies the grinding wheel dynamics in orbital atherectomy – a catheter-based minimally invasive procedure to pulverize plaque in atherosclerotic arteries using a diamond grinding wheel. Experiments were conducted to investigate the grinding wheel motion and grinding forces in orbital atherectomy. A high-speed camera and subsequent image processing were utilized to visualize and quantitatively analyze the grinding wheel motion through a transparent arterial tissue-mimicking phantom made of polyvinyl chloride, while the grinding forces were measured by a piezoelectric dynamometer. Observed under typical orbital atherectomy grinding rotational speeds of 60,000, 90,000, and 120,000 rpm in a 4.8 mm diameter vessel, the grinding wheel motion was a combination of a low-frequency orbiting at 18, 38, 40 Hz and a high-frequency rotation of 1000, 1500, and 1660.4-1866.1 Hz, respectively. Grinding forces consisted of the high and low frequencies that matched well with the wheel motion.