A Caltech Library Service

Location-aware ingestible microdevices for wireless monitoring of gastrointestinal dynamics

Sharma, Saransh and Ramadi, Khalil B. and Poole, Nikhil H. and Srinivasan, Shriya S. and Ishida, Keiko and Kuosmanen, Johannes and Jenkins, Josh and Aghlmand, Fatemeh and Swift, Margaret B. and Shapiro, Mikhail G. and Traverso, Giovanni and Emami, Azita (2023) Location-aware ingestible microdevices for wireless monitoring of gastrointestinal dynamics. Nature Electronics, 6 (3). pp. 242-256. ISSN 2520-1131. doi:10.1038/s41928-023-00916-0. (In Press)

Image (JPEG) (Extended Data Fig. 1: Coil embodiments for different use-cases) - Supplemental Material
See Usage Policy.

Image (JPEG) (Extended Data Fig. 2: Localization error of iMAG as a function of distance from the coils) - Supplemental Material
See Usage Policy.

Image (JPEG) (Extended Data Fig. 3: X-Ray scans for fecal incontinence study) - Supplemental Material
See Usage Policy.

Image (JPEG) (Extended Data Fig. 5: iMAG trajectory compared to the meanders in colon) - Supplemental Material
See Usage Policy.

Image (JPEG) (Extended Data Fig. 6: iMAG for smart toilets) - Supplemental Material
See Usage Policy.

[img] PDF (Supplementary Figs. 1–15, Table 1 and links to videos for Extended Data Figs. 3 and 4) - Supplemental Material
See Usage Policy.


Use this Persistent URL to link to this item:


Localization and tracking of ingestible microdevices in the gastrointestinal (GI) tract is valuable for the diagnosis and treatment of GI disorders. Such systems require a large field-of-view of tracking, high spatiotemporal resolution, wirelessly operated microdevices and a non-obstructive field generator that is safe to use in practical settings. However, the capabilities of current systems remain limited. Here, we report three dimensional (3D) localization and tracking of wireless ingestible microdevices in the GI tract of large animals in real time and with millimetre-scale resolution. This is achieved by generating 3D magnetic field gradients in the GI field-of-view using high-efficiency planar electromagnetic coils that encode each spatial point with a distinct magnetic field magnitude. The field magnitude is measured and transmitted by the miniaturized, low-power and wireless microdevices to decode their location as they travel through the GI tract. This system could be useful for quantitative assessment of the GI transit-time, precision targeting of therapeutic interventions and minimally invasive procedures.

Item Type:Article
Related URLs:
URLURL TypeDescription ReadCube access InCaltech News
Sharma, Saransh0000-0002-5052-4932
Srinivasan, Shriya S.0000-0002-2508-1324
Ishida, Keiko0000-0003-0894-296X
Jenkins, Josh0000-0001-7698-9888
Aghlmand, Fatemeh0000-0002-5103-9314
Swift, Margaret B.0000-0001-9610-0687
Shapiro, Mikhail G.0000-0002-0291-4215
Traverso, Giovanni0000-0001-7851-4077
Emami, Azita0000-0002-6945-9958
Additional Information:© 2023 Nature Publishing Group. We acknowledge the contribution of Standard Technology Inc. (FL) in the assembly of gradient coils. We are grateful to the members of MICS Lab (Caltech) for insightful comments and discussions. This research was funded in part by the National Science Foundation under grant 1823036 (A.E. and M.G.S.); in part by the Rothenberg Innovation Initiative under grant 101170 (A.E. and M.G.S.); in part by the Heritage Medical Research Institute under grant 150901 (A.E. and M.G.S.); and in part by a grant from the Karl van Tassel (1925) Career Development Professorship, the Department of Mechanical Engineering at MIT (G.T.). K.B.R. was supported by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the National Institutes of Health (NIH) under award no. F32DK122762 and the Division of Engineering at New York University, Abu Dhabi. These authors contributed equally: Saransh Sharma, Khalil B. Ramadi. These authors jointly supervised this work: Mikhail G. Shapiro, Giovanni Traverso, Azita Emami. Contributions. S.S., K.B.R., N.H.P., S.S.S., M.G.S., G.T. and A.E. conceived and designed the research. S.S. designed and assembled the iMAG devices, EM coils for gradient generation and all the electronics. S.S. performed all the in vitro characterization and localization experiments. K.B.R., S.S. and S.S.S. performed the in vivo characterization and localization experiments. N.H.P. and S.S. programmed the nRF chipset on iMAG and the receiver. S.S. performed all the data processing. K.I., J.K. and J.J. helped during the in vivo experiments. F.A. helped with the iMAG PCB design. M.B.S. helped during the in vitro characterization. S.S. wrote the manuscript, with input from all the other authors. M.G.S., G.T. and A.E. supervised the research. Data availability. The data that support the findings of this study are available from the corresponding authors upon reasonable request. Code availability. Codes used in this study are available from the corresponding authors upon request. Competing interests. S.S., M.G.S. and A.E. have joint US patents (20,210,137,412 and 11,457,835 B2) on the localization and magnetic-field generation concepts. M.G.S. and A.E. are founding members of Tychon Technologies. All the other authors declare no competing interests.
Group:Heritage Medical Research Institute, Tianqiao and Chrissy Chen Institute for Neuroscience
Funding AgencyGrant Number
Rothenberg Innovation Initiative (RI2)101170
Heritage Medical Research InstituteHMRI-15-09-01
Massachusetts Institute of Technology (MIT)UNSPECIFIED
NIH Postdoctoral FellowshipF32DK122762
Issue or Number:3
Record Number:CaltechAUTHORS:20230214-651108000.1
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:119259
Deposited By: George Porter
Deposited On:14 Feb 2023 20:45
Last Modified:09 May 2023 19:26

Repository Staff Only: item control page