Human organ phantoms for catheterization using the radiation crosslinking technique

An artificial organ based on polyvinyl alcohol (PVA) hydrogel was developed to train medical staff to improve their ablation therapy skills, by using the radiation cross-linking technique. The aqueous PVA solution was irradiated with gamma-rays or electron beams to produce a highly transparent, high-strength, and flexible crosslinked hydrogel without using a crosslinking agent. Physical properties of the hydrogel, such as, gel fraction, swelling, and elastic modulus, were controlled by changing the radiation dose. The catheter ablation region on the surface of the cardiac phantom produced from PVA hydrogel with temperature-responsive pigment inks can be visually identified by the color change. The tumor organ phantom consists of the PVA hydrogel with the purple pigment ink (healthy organ site) and red PVA hydrogel with cellulose (the tumor sites) was developed by applying this radiation crosslinking technique. The positions of the tumor hydrogel and the ablation electrode needle can be confirmed through ultrasound echography. It is possible to practice ablation on the tumor site while observing the echo images under conditions similar to the actual treatment. These novel human organ phantoms are created as a means for ablation training for treating cardiac arrhythmia and liver cancer using the radiation crosslinking technology.