Double Balloon Pericardiocentesis Gelatin Phantom

by Richard Byrne, MD 120 minutes ~$20 14 steps

CardiacPericardiocentesisIntermediateSimulatorAnatomy ModelTeaching Aid

Overview

This model simulates a pericardial effusion for practicing ultrasound-guided pericardiocentesis. It uses a double-balloon system embedded in colored gelatin to replicate the heart and pericardial space. The inner balloon contains red-dyed water (simulating the heart chamber) and the outer balloon contains blue-dyed water (simulating pericardial fluid), all suspended in green Betadine-tinted gelatin representing surrounding tissue.

Materials

20 oz plain gelatin
1 16-inch diameter punching bag balloon
1 small regular balloon
3 vials of food coloring (red, blue, and green suggested)
Non-stick cooking spray
1 wooden cooking skewer
4 oz Betadine
Approximately 1L of water
1 3-quart cubical tupperware container
1 6-quart tall stock pot or saucepan
Candy thermometer (suggested)
Stove
Refrigerator

Steps

Mix Gelatin with Cold Water

Mix 250-500cc cold water and gelatin together in the 3-quart tupperware container until combined.

Refrigerate Gelatin Mixture

Cool the gelatin mixture in the refrigerator for two hours.

Assemble Double Balloon

Place the first (smaller) balloon inside the 16-inch punching bag balloon, leaving the stem of the smaller balloon accessible outside the stem of the bigger balloon.

Fill Inner Balloon with Red Water

Add 100-150mL of water dyed with red food coloring into the stem of the smaller balloon. Tie this stem off to seal it.

Fill Outer Balloon with Blue Water

Add another 100-150mL of water dyed with blue food coloring into the stem of the punching balloon. Tie off the balloon to seal it. You should now have one balloon sealed inside another balloon.

Prepare Tupperware Container

Coat the 3-quart tupperware container with non-stick cooking spray.

Heat Gelatin on Stovetop

Remove the gelatin mixture from the refrigerator and transfer it to the 6-quart pot. Heat on the stovetop until the gelatin is fully liquefied. Use a candy thermometer to ensure the mixture does not exceed 130°F. As the gelatin liquefies, add several drops of green food coloring and 4 oz of Betadine.

Pour Base Layer of Gelatin

Pour the liquefied gelatin mixture into the prepared tupperware container to a depth of 2cm. Place in the refrigerator and cool until firm.

Position Balloon on Gelatin Base

Place the double balloon on top of the set gelatin layer in the center of the tupperware container with the tied end facing upward.

Secure Balloon with Skewer

Secure the balloon in position by feeding the wooden skewer through the tied balloon knot and wedging the skewer across the inside of the tupperware container to hold it in place.

Fill Container to Skewer Level

Fill the tupperware container with the liquefied gelatin mixture until the level reaches just below the wooden skewer. Place in the refrigerator and cool until firm.

Remove Skewer and Top Off Gelatin

Remove the wooden skewer and fill the tupperware container to the brim with the remaining liquefied gelatin mixture.

Final Refrigeration Until Set

Place the container in the refrigerator and cool until the entire mold is firmly set.

Unmold and Use Model

Remove the completed model from the tupperware container and begin use for pericardiocentesis training.