Preparation of prototypes

Catheters were prepared as previously described (Levering, et al. 2016). Briefly, extruded silicone catheter shaft components (Vesta Inc., Lanham, Maryland, USA) were generated according to provided specifications using Dow Corning two-part, platinum-catalyzed Class VI silicone feedstock. Silicone feedstock was used to achieve 35 durometer multi-lumen silicone main shafts and the 65 durometer silicone sheath (all durometers defined per the type A scale). The sheath was slip-fitted over the main shaft using isopropyl alcohol. The inflation lumens were then sealed using Sil-Poxy® silicone adhesive (Smooth-on Inc., Macungie, PA, USA). Long holes (~ 2 mm) were made in the outer walls of the inflation lumen ~ 1 cm from the designated hub end of the shaft. Hub manifolds were prepared by pouring silicone (Dragon Skin 0020®, Smooth-On Inc., Macungie, PA, USA) into a mold prepared by a 3-D printer as described previously (Levering, et al. 2014). Once cured, the hubs were removed from the molds and then pierced and fitted with a male Tuohy-Borst connector to be used for inflation of the intralumens. The hubs were fitted over the designated end of the shaft and carefully glued the hub in place without occluding the holes in the inflation lumens. This permitted the simultaneous on-demand inflation of all four lumens via the Tuohy-Borst connector. The prototypes were sterilized with ethanol before use.