The gastrointestinal (GI) tract offers the opportunity to detect physiological and pathophysiological signals from the human body. Ingestible electronics can gain close proximity to major organs through the GI tract and therefore can serve as clinical tools for diagnostics and therapy. In this Review, we summarize the physiological and anatomical characteristics of the GI tract, which present both challenges and opportunities for the development of ingestible devices. We describe recent breakthroughs in materials science, electrical engineering and data science that have permitted the exploration of technologies for sensing and therapy via the GI tract. Novel sensing opportunities include electrochemical, electromagnetic, optical and acoustic protocols, which have the capacity to sense luminal or extra-luminal analytes in the GI tract. We review therapeutic interventions, such as anatomical targeting for drug delivery, delivery of macromolecules and electrical signals. Finally, we investigate major challenges associated with ingestible electronics, including safety, communication, powering, steering and tissue interactions. Ingestible electronics are an exciting area of scientific innovation and they may pave the way for a new era in medicine, enabling patients to receive remote, electronically assisted health care.
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The authors thank H. Sun, currently a visiting student at the Massachusetts Institute of Technology (MIT), for help with the artwork. This work was funded in part by the Alexander von Humboldt Foundation (Feodor Lynen Fellowship to C.S.), the National Institutes of Health (grant no. EB-000244) and a Max Planck Research Award (to R.L., award letter dated 11 Feb 2008). G.T. was supported in part by the Division of Gastroenterology, Brigham and Women’s Hospital.
All authors are co-inventors on multiple patents or patent applications describing ingestible electronics and auxiliary systems. G.T. and R.L. have financial interest in Suono Bio, Celero Systems and Lyndra, Inc. These companies are developing a set of distinct approaches to drug delivery and, in some instances, incorporate electronics into their systems. P.N. is an employee of Analog Devices, Inc.
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IFAC, dielectric properties of body tissues: http://niremf.ifac.cnr.it/tissprop
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Steiger, C., Abramson, A., Nadeau, P. et al. Ingestible electronics for diagnostics and therapy. Nat Rev Mater 4, 83–98 (2019). https://doi.org/10.1038/s41578-018-0070-3
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