Experimental investigation on tool geometry and cutting speed effects in mechanical thrombectomy: from clot analog preparation to prototype verification

Clots will always result in the slowing or complete blockage of intravascular blood flow, which finally cause the ischemic disease. Mechanical thrombectomy (MT), as a novel interventional therapy, is gaining prominence in clinical practice. The process parameters during MT directly affect the clot cutting and fracture failure characteristics. This study utilized porcine blood to create a clot model for cutting experiments, investigating the effects of cutting process and tool structure on the clot cutting failure characteristics. The results indicate that both cutting speed and tool structure significantly affect cutting force and tool displacement, with tool structure being the predominant factor. When the cutting speed varies from 10 mm min^-1to 400 mm min^-1, the cutting force reaches its minimum at 220 mm min^-1, with a maximum reduction of approximately 5 N. The tool with larger rake angle exhibit the greatest influence on cutting force, while the presence of inclination significantly increases the deformation displacement of the tool. These findings provide valuable insights for optimizing the design of MT devices, ultimately enhancing the efficiency and safety of thrombus procedures.