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Pilot Validation of a New Wireless Patch System as an Ambulatory, Noninvasive Tool That Measures Gut Myoelectrical Signals: Physiologic and Disease Correlations

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Background and Aims Limited means exist to assess gastrointestinal activity in a noninvasive, objective way that is highly predictive of underlying motility disorders. The aim of this paper is to demonstrate the feasibility of recording myoelectric gastrointestinal activity by cutaneous patches and to correlate myoelectric signals with gastrointestinal function in various clinical settings. Methods A novel wireless patch system (WPS) (G-Tech Medical) that acquires gastrointestinal myoelectrical signals was placed on the patients’ anterior abdomens. Data were transmitted wirelessly to a mobile device with a user interface and forwarded to a cloud server where processing algorithms identified episodes of motor activity, quantified their parameters, and nominally assigned them to specific gastrointestinal organs based on their frequencies. Results The inherent reproducibility of the WPS measurement technique itself and from the underlying gut activity, coupled with source validation and sensitivity to changes in gut activity in several physiologic and pathologic states, demonstrates its feasibility, safety, and performance in clinical settings. Conclusions The novel WPS technology, measuring myoelectric intestinal activity noninvasively and continuously over multiple days, is feasible in a wide range of clinical settings, highlighting its promise in the diagnosis and management of motility disorders. Further research is required for more extensive validation and to determine how best to employ this information to optimize patient care.
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Digestive Diseases and Sciences (2021) 66:3505–3515
https://doi.org/10.1007/s10620-020-06663-y
ORIGINAL ARTICLE
Pilot Validation ofaNew Wireless Patch System asanAmbulatory,
Noninvasive Tool That Measures Gut Myoelectrical Signals: Physiologic
andDisease Correlations
LindsayAxelrod1· SteveAxelrod1· AnandNavalgund1· GeorgeTriadalopoulos2
Received: 28 June 2020 / Accepted: 6 October 2020 / Published online: 15 October 2020
© Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract
Background and Aims Limited means exist to assess gastrointestinal activity in a noninvasive, objective way that is highly
predictive of underlying motility disorders. The aim of this paper is to demonstrate the feasibility of recording myoelectric
gastrointestinal activity by cutaneous patches and to correlate myoelectric signals with gastrointestinal function in various
clinical settings.
Methods A novel wireless patch system (WPS) (G-Tech Medical) that acquires gastrointestinal myoelectrical signals was
placed on the patients’ anterior abdomens. Data were transmitted wirelessly to a mobile device with a user interface and
forwarded to a cloud server where processing algorithms identified episodes of motor activity, quantified their parameters,
and nominally assigned them to specific gastrointestinal organs based on their frequencies.
Results The inherent reproducibility of the WPS measurement technique itself and from the underlying gut activity, coupled
with source validation and sensitivity to changes in gut activity in several physiologic and pathologic states, demonstrates
its feasibility, safety, and performance in clinical settings.
Conclusions The novel WPS technology, measuring myoelectric intestinal activity noninvasively and continuously over
multiple days, is feasible in a wide range of clinical settings, highlighting its promise in the diagnosis and management
of motility disorders. Further research is required for more extensive validation and to determine how best to employ this
information to optimize patient care.
Keywords Myoelectrical recordings· Gut motility· Constipation· Gastroparesis
Introduction
The frequency of functional gastrointestinal disorders
(FGID) is quite disturbing worldwide. The number of yearly
office visits (in millions) in the USA for abdominal pain is
15, diarrhea, 4.5, constipation, 2.4, and altered bowel hab-
its, 1.3, while the worldwide prevalence of irritable bowel
syndrome (IBS) is 11%. In turn, the prevalence of chronic
idiopathic constipation is 14% [1, 2].
Over many decades, significant technological develop-
ments have allowed the study of the gut and its underlying
motility patterns and have included ingestion of radiopaque
markers [3], gastrointestinal scintigraphy [4], breath tests
[5], and wireless motility capsules [6]. Other tests that study
the contractility or sensation of the gastrointestinal tract have
been more invasive and typically require endosopic intuba-
tion [7], hence restricting their widespread use. What has
been missing through the years is the gut equivalent of the
“electrocardiogram” that is noninvasive, easy to use, and
highly predictive of underlying disorders.
To date, the diagnosis of various disorders by measuring
myoelectrical signals that originate from the gastrointesti-
nal smooth muscles over multiple days with the potential
of relating abnormal gut motility to specific symptoms
remains the subject of imagination. For example, under-
standing the impact of diet or drugs on gut function, decid-
ing how to monitor and expedite gut recovery after surgery,
* George Triadafilopoulos
vagt@stanford.edu
1 G-Tech Medical, Fogarty Institute forInnovation, 2495
Hospital Drive, Suite 300, MountainView, CA94040, USA
2 Division ofGastroenterology andHepatology, Stanford
University School ofMedicine, 430 Broadway St., Pavilion
C, 3rd Floor, GI Suite, RedwoodCity, CA94063, USA
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... 2,5,7 The motor activity of the GI tract is driven by the rhythmic electrical activity of ICC, which may be measured by an external recording system. 2 Our group previously introduced the wireless skin patch myoelectric measurement system to detect myoelectric signals of different parts of the GI tract. 5,[8][9][10] The aim of this study is to determine the correlation between external patch measurements and internally measured myoelectrical signals. Pigs were used as a model for the human GI system. ...
... Data were then downloaded and processed to represent organ-specific waves across the GI system. 10 Animal care and surgery Stanford Administrative Panel on Laboratory Animal Care approved animal care and surgical procedures (protocol number:33,264). Four female, juvenile, miniature Yucatan pigs (Sus scrofa, S&S Farms, Ramona, CA) were used for the experiment. ...
... 2 The most common symptoms of GI motility disorders are chronic abdominal pain, bloating, nausea, constipation, or diarrhea. 10 They are common, affecting 10 to 15% of the U.S. population. The annual cost of GI motility disorders on the U.S. health system is USD 29 billion. 2 Anesthesia or GI manipulation during abdominal surgeries can result in disturbance of GI motility as well. ...
Preprint
Introduction Currently, there is no accurate noninvasive measurement system to diagnose gastrointestinal (GI) motility disorders. Wireless skin patches have been introduced to provide an accurate noninvasive measurement of GI myoelectric activity which is essential for developing neuro-stimulation devices to treat GI motility disorders. The aim of this study is to compare the external and internal electrical signal measurements in ambulatory pigs. Methods Yucatan pigs underwent placement of internal electrodes on the stomach, small intestine, and colon. Wires were brought through the abdominal wall. Signals were collected by a wireless receptor. Four external patches were placed on the abdominal skin to record the signals simultaneously. Pigs were kept for 6 d while the sensors were continuously recording the data from both systems. Results Internal sensors detected rich signals from each organ. The stomach had a dominant frequency that ranged from 4 to 4.5 cpm, with occasional higher frequencies at 2, 3 and 4 times that. Small intestine signals had their primary energy in the 12-15 cpm range. Colon signals primarily displayed a dominant broad peak in the 4-6 cpm region. External skin patches detected a substantial fraction of the activities measured by the internal electrodes. A clear congruence in the frequency spectrum was observed between the internal and external readings. Conclusions Internally measured myoelectrical signals confirmed different patterns of rhythmic activity of the stomach, small intestine, and colon. Skin patches provided GI myoelectric measurement with a range of frequencies that could be useful in the diagnosis and treatment of motility disorders.
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