Quipu-Inspired, Liquid Metal-Enabled Pressure Transducers (QUILT) for Low-Cost Gastrointestinal Manometry

The evaluation of tone and contractile patterns of the gastrointestinal (GI) tract is an essential aspect in the diagnosis of GI motility disorders. Although manometry represents the current primary mode of GI motility assessment, it is expensive, complex and bulky, therefore limiting its use to mostly well-resourced and high-volume referral centers. Here we aim to develop a system that is inexpensive and easy to manufacture, yet capable of capturing manometric data across the dynamic range observed in the human GI tract. Inspired by the quipu, a form of communication used by Andean civilizations in the Americas that applies knots for the capture and transmission of information, we infuse thin silicone tubing with liquid metal and explore a range of knots and knotting configurations to identify the optimal design schemes as a basis for low-cost and disposable pressure transducers based on the piezoresistive effect of elastic silicone/liquid metal composites under applied pressure, which have comparable performances with commercial GI manometry. We characterize the performance of the system both in vitro and in vivo in a porcine model, demonstrating its capacity to sense motility in multiple anatomic sites of the GI tract. Together, these results demonstrate an economical and customizable alternative to GI manometry.