The blood vessel model. (a) Design drawing that formed the basis for the training tool. The blood vessel model mainly replicated the central venous system. Note that 3 ringed thin protuberances were made in the part corresponding to the inferior vena cava below the renal vein. (b) Photograph shows appearance of the bare model. Holes were created at 3 sites, which are areas corresponding to the cervical and right and left femoral veins, from which a sheath introducer can be inserted (arrows). All holes can be covered when not used. Note the 3 ringed thin protuberances (arrowheads). (c) Photograph shows training of withdrawal of the filter with this tool.