This study investigates the effectiveness and behaviour of a device for removing thrombi and embolisms, called the Wireless Clot Retriever (WCR). The WCR features an Untethered Magnatic Robot (UMR), a WCR head, which features fins which function like barbs, hooking into the blood clot, and finally a needle connecting the two. Evaluating the effectiveness was done by investigating the current design and making a new design, for which multiple parameters were varied.
These parameters included the length and width of the fins, the number of fins and the surface friction of the WCR. The surface friction was altered by applying a coating. These designs were tested by measuring the deflection of the fins in gelatin and the force needed to extract the WCR from a blood clot. The results show no impact on force for the number of fins, only having reduced force with zero fins. The coating reduced the reliability of the extraction force. The different fin dimensions show no significant difference. The deflection angle testing revealed buckling and twisting of the fins, possibly reducing performance.
In conclusion, friction plays an important role in the generation of extraction force, with the outward bending of the fins being limited, along with the force generated as a result of this.