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Device Technologies and Biomedical Robotics

Device Technologies and Biomedical Robotics - Poster Session E

Poster W1 - InTester: an electromechanical model of the human small intestine

Saturday, October 26, 2024
10:00 AM – 11:00 AM EST
Location: Exhibit Hall E, F & G

Introduction:  The InTester is an electromechanical model of the human small intestine that represents a significant advancement in the simulation of gastrointestinal mechanics, addressing a critical unmet need in biomedical research and drug development. The InTester replicates the physiologic contractions of the small intestine, providing a platform to observe how motility impacts the passage of ingested matter or test therapeutic or diagnostic devices. Our extensive literature review and interviews with clinicians and researchers in the field revealed that existing gastrointestinal simulators lack several essential abilities: to load real ex vivo tissue, to program contractions to replicate physiologic metrics, and to maintain a user-friendly, compact form factor. The InTester overcomes these limitations with innovative design elements such as programmable, soft robotic pressure cuffs that produce contractions mimicking those in the gut. With these features, the InTester has already driven the development of a novel oral therapeutic device and offers significant translational potential, particularly for pharmaceutical companies interested in studying the effects of gut contractions on drug formulations. Additionally, its modularity allows for easy customization, making it a versatile tool for various research applications, such as aiding the development of novel ingestible devices that can withstand or harness the dynamic gut mechanics. The InTester's user-friendly design, requiring only a single power supply and simple operational buttons, further enhances its practicality for laboratories. Its ability to simulate the physical processes of digestion in a realistic manner promises significant benefits across medical research, pharmaceutical development, and food and nutrition studies.

Materials and

Methods:  The design and execution of creating the InTester focused around its four main parts: frame, mold, electronics, and case. The frame, water jet cut from polycarbonate sheets, provides the structural foundation for the InTester. The mold employs an innovative use of silicone rubber, housing the InTester’s critical motors, valves, and connectors, and is essential for vibration damping. The electronics feature a custom printed circuit board (PCB) with embedded microcontroller that precisely controls the pressure cuffs' inflation and deflation to achieve physiologic contraction metrics. These components were carefully designed and iteratively tested to ensure reliability. The case, designed using CAD software and 3D printed, encloses the electronics and includes slots for buttons and an OLED display, contributing to function and aesthetics. The InTester has a modular design that allows for adjustments, such as adding more motors or pressure cuffs, to accommodate different research needs. The InTester's ability to load both ex vivo and in vitro gut tissues enables realistic simulations of the small intestine, providing a valuable tool for testing and refining oral therapeutic devices. Materials and methods selected to create the InTester ensure its overall effectiveness and usability in laboratory settings.

Results, Conclusions, and Discussions: The InTester has demonstrated its effectiveness in replicating the physiologic contractions of the small intestine, significantly advancing our understanding and development of oral therapeutic devices. By loading the machine with fresh ex vivo pig small intestine tissue, we were able to replicate contractions with key physiologic metrics, including a force of 0.7 N, a duration of 4.8 seconds, and a frequency of 12 contractions per minute. These capabilities were validated by inserting an electronic pill embedded with a force sensor into the mock gut and achieving the desired contraction metrics. Additionally, the InTester enabled the testing of a contraction-based oral device under physiologic contraction metrics and informed the design of the device through experiments showing that the addition of a stabilizer to an injector improves its injection success rate from 0% to 80%.The machine also enabled visualization of pill movement through a transparent in vitro gut tissue, revealing that contraction-induced movement can be effectively studied. The InTester offers a cost-effective alternative to in vivo models, which are often expensive and ethically challenging. With a total cost of under $150, the InTester provides significant value for research laboratories. Its ability to simulate realistic gut mechanics holds potential for broad applications in drug delivery research, food science, and beyond. Future work will focus on further validation and optimization of the machine, aiming to reduce dependency on animal models and accelerate the development of novel ingestible devices.

Acknowledgements (Optional):  We thank Neil Gershenfeld for advice; Suwan Kim and staff at the MIT Architecture Shops (Jennifer O’Brien and Shah Paul) for assistance with prototyping; and Qiwen Peng for assistance with experiments.