Poster Y2 - Abdomen Testing Model for Benchtop Testing of Ostomy Bags

Introduction: Ostomy surgery diverts a portion of the intestine through a hole in the abdomen called a stoma and helps treat various intestinal diseases and conditions. Waste (effluent) exits the body through the stoma, necessitating that ostomates (people with ostomies) wear waste collection bags that adhere to the abdomen. Commercially available ostomy bags are typically designed to be single-use and cost each ostomate up to $15,000 per year [1], meaning uninsured and underinsured ostomates in the United States face high recurring costs and accessibility barriers. As a result, these ostomates often use repurposed household items to create low-fidelity, homemade solutions that are difficult to maintain, emit embarrassing odors, and increase the risk of serious infection at the stoma. To address this gap, we are developing a low-cost reusable ostomy bag. Before our product is tested with ostomates, there is a need to validate prototypes through lab testing. We developed a benchtop abdomen-stoma model that mimics abdominal skin texture, curvature, and tissue stiffness with an embedded stoma and tube system to enable simulation of effluent flow. This model will support design iteration and testing of reusable ostomy bag prototypes.

Materials and

Methods: Our benchtop abdomen-stoma model replicates anatomy of an ostomy site with the ability to simulate effluent flow from the stoma. Medical gelatin (#4, Humimic Medical) serves as the model’s base, imitating physical characteristics of soft tissue and subcutaneous fat, which allows a more realistic simulated application of the ostomy system to the abdomen. The model includes a silicone stoma (Replacement Flush Stoma, Vata Inc) connected to tubing that feeds through the back of the medical gel. This allows simulated effluent to flow through the stoma and mimic realistic ostomy effluent excretion, allowing prototypes to be tested for leaking. Applesauce was used to mimic effluent as it has similar properties and consistency to real stoma output, which averages 600 to 1400mL per day [5]. Simulated skin (Vitro-Skin, Medelink) is placed on top of the medical gelatin to simulate skin covering abdominal subcutaneous tissue. The material texture properties of Vitro-Skin mimic those of real skin, enabling more realistic adherence of prototypes during testing. All components are contained in a 3D-printed PLA frame, with an opening for the gel, that is curved to simulate the anatomical bend of a human abdomen (Figure 1).

Results, Conclusions, and Discussions: Commercial bags were attached to the model and effluent was passed into the bag. Preliminary testing indicates that a commercial ostomy bag can be easily applied to our model and effluent flow can be simulated. Further efforts are currently underway to test the model's ability to bear the weight of a full ostomy bag and undergo multiple leakage scenarios. Additional plans include incorporating the ability to bend or twist as well as ensuring the model is completely reusable after each test. We have successfully developed a benchtop testing model that replicates a human abdomen in the properties of skin texture, abdomen softness, and abdomen curvature, and have demonstrated that the model mimics important aspects of ostomy bag behavior on ostomates. This model will allow us to conduct thorough benchtop testing and rapid iteration with future prototyped bags before moving on to human subject testing.

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