Fig 1.

Hybrid hydrogel-platinum coil device. Top, prehydration image shows initial profile of the device. Highly compact hydrogel material is wrapped around a platinum coil. Indentations between winds of the underlying platinum coil can be seen through the compact hydrogel material (straight white arrow). The outer diameter of the coil is 0.008 inch; the thickness of the hydrogel is approximately 0.001 inch, such that the outer diameter of the device is 0.010 inch. Bottom, post-hydration image of the device shows marked expansion of the hydrogel material, which has become translucent. The outer edges of the hydrogel are denoted by the curved white arrows. The platinum coil is denoted by the black arrow. The radial thickness of the expanded hydrogel is approximately 0.013 inch, such that the total outer diameter of the hydrated device is 0.035 inch.