Improving Longevity of Gelatin Ultrasound Trainers

Abstract

Medical schools are increasingly integrating ultrasound training into their curricula as ultrasound utility expands in medical practice. Homemade ballistic gelatin ultrasound trainers have been developed as teaching tools that bypass the logistical complications of human test subjects and expense of commercial phantoms. This study explored methods to impede mold growth and extend the longevity of homemade trainers through chemical additives and physical barriers. Thirty‐five 500 mL forms with a base formula of gelatin (10% by weight) and Metamucil (2.5% by weight) in water were created in 750 mL Tupperware containers. Five had no additives or surface coverings; 8 contained the preservative Carolina's Perfect Solution; 7 contained the antiseptic surgical scrub Betasept; and 5 each had the exposed surface covered in plastic wrap, Duoderm bandages, or Tegaderm bandages. All containers were lidded, refrigerated at 4⁰ C and checked weekly for number and diameter of growing mold colonies. By week 6, all gelatin forms except those treated with Betasept or covered with Duoderm bandages had developed mold, with colony number ranging from 1‐4 and diameters from 1‐16 mm. While 2 of 5 Duoderm trials developed mold in week 10, all Betasept trials remained mold free through 25 weeks. Adding 1% Betasept by weight during gelatin trainer creation is recommended as a low cost, low hazard method for preventing mold growth.