PMC

Response of the non-symmetric voltage pairs around the test heater as a function of time at a heater pulse of 0.4 A for 7 s. The coil operating current is 100 A. Two dashed lines represent the start of the normal zone and the turn-off the coil current, respectively. NZPV was measured at a constant coil operational current, before the shut-off of the coil current.

A, Schematic illustration of the polymeric coil system (above) and the delivery/detacher device (below). The coil system consists of a proximal shaft (open arrow, ink marker) attached to a hemostatic valve and a distal 65-cm-long radiopaque polymeric strand with an outer diameter of 0.018 inch (asterisk). The delivery/detacher device (total length, 270 cm) is introduced through the hemostatic valve into the inner lumen of the coil system. The delivery/detacher device consists of the microwire (arrowhead) and the heater coil attached to its distal tip (arrow). B, Fluoroscopy of an in vitro silicon aneurysm model showing the radiopaque polymeric strand (black asterisk) within the microcatheter placed in the aneurysm (microcatheter tip, open arrow) and its unfolded distal part within the aneurysm sac (white asterisk). Note the radiopaque section of the heater coil (arrow) at the distal tip of the delivery/detacher device (arrowhead) running within the coil strand. The polymeric strand can be detached at any point by advancing the radiopaque section of the heater coil at the level of the microcatheter tip and activating the thermal detachment. C, Photographic depiction of the silicon aneurysm model after introduction of the polymeric coil.

(a) HRM heater probe schematic of heater wire coil inside the micropipette connected to the positive voltage extension wire. (b) HRM heater probe schematic of micropipette located inside the steel dispensing needle, connection of the negative voltage extension wire to the heater wire, and heat shrink tubing and glue securing the positive voltage extension wire to the needle’s plastic hub.

Coil quench measurement at I_op =185 A. Test heater pulse of 0.35 A for 2 s (15.5 J) was used to initiate the quench. An active protection heater pulse of 90 A for 21 s (68 kJ) was used to protect the coil.