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Low-cost gastrointestinal manometry via silicone–liquid-metal pressure transducers resembling a quipu


The evaluation of the tone and contractile patterns of the gastrointestinal (GI) tract via manometry is essential for the diagnosis of GI motility disorders. However, manometry is expensive and relies on complex and bulky instrumentation. Here we report the development and performance of an inexpensive and easy-to-manufacture catheter-like device for capturing manometric data across the dynamic range observed in the human GI tract. The device, which we designed to resemble the quipu—knotted strings used by Andean civilizations for the capture and transmission of information—consists of knotted piezoresistive pressure sensors made by infusing a liquid metal (eutectic gallium-indium) through thin silicone tubing. By exploring a range of knotting configurations, we identified optimal design schemes that led to sensing performances comparable to those of commercial devices for GI manometry, as we show for the sensing of GI motility in multiple anatomic sites of the GI tract of anaesthetized pigs. Disposable and customizable piezoresistive catheters may broaden the use of GI manometry in low-resource settings.

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Fig. 1: QUILT.
Fig. 2: Experimental and numerical approaches to enhance sensor performance.
Fig. 3: Strategies for multiplexed measurements.
Fig. 4: In vivo demonstration of QUILT for gastrointestinal manometry.
Fig. 5: Benchmarking QUILT against clinically available pressure sensors.

Data availability

The main data supporting the results in this study are available within the paper and its Supplementary Information. Source data for the figures are available from figshare with the identifiers (Fig. 4) and (Fig. 5).

Code availability

The code used to generate the plots in Figs. 4c,d and 5g,j is available from the corresponding author on reasonable request.


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We thank A. M. Hayward, K. Ishida and J. Jenkins for supervising and performing the in vivo experiments using Yorkshire swine models; M. Kolle for insightful discussions on knot mechanics; and H. Luan for helping with finite-element modelling. This work was supported in part by the Karl van Tassel (1925) Career Development Professorship and the Department of Mechanical Engineering, MIT.

Author information

Authors and Affiliations



K.N. and G.T. conceived and designed the study. K.N. fabricated and characterized the QUILT. S.B., C.M.P. and A.M.J. performed the mechanical analysis and the finite-element modelling. J.L.P.K., K.N., S.S.S. and V.R.F. performed the in vivo experiments on porcine models. V.R.F. synthesized and optimized the artificial food bolus. W.W.C. advised on the clinical aspects of this project and wrote a substantial portion of the manuscript. All authors discussed and interpreted the results, and participated in writing and editing the manuscript.

Corresponding author

Correspondence to Giovanni Traverso.

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Competing interests

The authors report a patent application (U.S. Provisional Application No. 63/301,491) describing the system described for manometric evaluation. Complete details of all for-profit and not-for-profit relationships for G.T. are included in the Supplementary Information. The other authors declare no competing interests.

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Peer review information

Nature Biomedical Engineering thanks Michael Dickey, Pankaj Pasricha and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Peer reviewer reports are available.

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Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Table 1, Figs. 1–19, References, video captions and details of competing interests for G.T.

Reporting Summary

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Supplementary Video 1

Formation of an elastic overhand knot using finite-element simulations.

Supplementary Video 2

Finite-element simulations of knot compression.

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Nan, K., Babaee, S., Chan, W.W. et al. Low-cost gastrointestinal manometry via silicone–liquid-metal pressure transducers resembling a quipu. Nat. Biomed. Eng (2022).

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