In situ continuous monitoring of systemic gastric biomarkers
Figure 1. Schematic diagram demonstrating the concept to monitor systemic biomarkers with nasogastric (NG) compatible sensors. Gastric fluid (GF)/gas contains systemic biomarkers, and these can be monitored through A) aspiration
and continuous analysis with ex vivo systems or B) intragastric sensor placements via NG tubes. The sensor resides in the stomach and is immersed in GF which contains systemic biomarkers. C) Demonstrates a use case in which
a biomarker is monitored throughout the time period in between classical clinical laboratory testing to increase responsiveness of clinical care teams.
Figure 2. Coincidence of markers in serum and gastric fluid (GF). The plot shows a comparison of a set of analytes in serum- and GF. All but 8 out of 125 serum analytes (inner circle) are detectable in porcine GF (outer circle).
For simplification the pie chart only shows detectable serum analytes. All markers are shown in the bubble chart (n = 5 for each group, 154 detectable markers in total).
Gastric motility 3D mapping
(A) Illustration of the universal motility-mapping system with tubular and bolus sensing probes. (B) Deployment and retrieval workflow of the stomach motility probe. (C and D) Deployment and retrieval illustrations of (C) rectum
and (D) esophagus probe. (E and F) X-ray of tubular probe in (E) esophagus and (F) rectum. (G and H) X-ray (G) and endoscope image (H) of the bolus probe in the stomach. (I) Illustration of the bolus organ (stomach) motility
probe.
In situ continuous
monitoring of gastric electrophysiology
Schematic
representation of the MiGUT device containing electronics housed in an ingestible capsule
with
linear
recording electrodes stored in a rolled configuration. Following ingestion, the electrodes
unroll, come into contact
with the mucosa and record gastric biopotentials, which can be wirelessly transmitted to an
external receiver. The
recorded data can be processed to extract heart rate, gastric slow wave and respiration
rate.
Endoscopic
image
of MiGUT electrodes deployed against the gastric mucosa. Sensing electrodes (⌀5 mm) are
distinguished
from the reference (ref) electrode (⌀8 mm) by size. Inset: schematic of electrode and ref
configuration. Channel (Ch) 0
was near the pylorus and the capsule body; channel 7 and ref were near the corpus.
Unrolling of
MiGUT electrodes due to strain of polyimide ribbon following wetting of water-soluble
adhesive,
showing the
initial position (i), initiation of deployment (ii) and unrolling of electrodes (iii). Full
extent of MiGUT device,
total length of 25 cm. Dime and 000 gelatin capsules for scale.
Representative
single recording channel, sampling rate of 62.5 s−1, showing raw collected data, 200 s (i),
‘slow wave’
band from 0.01 to 0.25 Hz, 200 s (ii), ‘respiration’ band from 0.25 to 5 Hz, 30 s (iii),
‘EKG
spikes’ band from 5+ Hz
(iv). Third-order Butterworth filters were used to extract all frequency bands.
Eight-channel
recording for 3.5 h from a MiGUT device secured in the porcine stomach (0.01–0.25 Hz
band-pass
filter) of
a freely moving animal during feeding, ambulation and napping activities.
Electroceuticals for
intestinal reanimation
Figure 1.
Overview of the INSPIRE. (A) Mechanism of action of the inSPiRe for small intestinal
motility. (B) inSPiRe
form factor and geometry. (C) inSPiRe encapsulated in atriple-zero capsule with Pcb in view.
(D) Degraded inSPiRe after
2 hours of incubation in SiF. (E) expanded inSPiRe with battery in view. (F) three
predominant orientationsof the
inSPiRe in small intestinal tissue, enabling luminal contact of electrodes. Scale bars, 10
mm.
Figure 2.
Motility and biocompatibility. (A) the inSPiRe significantly decreased thenumber of days to
pass through the
tract, reflecting increased intestinal motility.(B) Motility rate was assayed by tracking
passage time using an RFtP.
Scale bar,10 mm. Representative small intestinal tissue samples from (C) a control
animaltreated with a sham pill and
(D) an animal treated with the inSPiRe demonstrate nosignificant difference. Scale bars, 1
mm (c and D).
In vivo gastrointestinal
dosimeter
Figure
1. (a) Optical images of the PIN photodiode and the encapsulated capsule electronics as
well as the associated
electrical schematic. (b) The schematics of the overall in vivo experimental setup. (c)
In vitro (left) and in vivo
(right) readouts of the PIN diode.
Figure
2. X-ray image of the encapsulated PIN photodiode positioned within the stomach of a
swine.
Fig.
4:Photodiode characterization using a LINAC to verify its reliability and consistency in
detecting X-rays of
varying intensities and energies. The photodiode response indicates the integral of the
resultant pulse for the duration
of irradiation. The dose-to-water represents the X-ray dose delivered to the photodiode
regarding the set X-ray voltage.
In situ detection of
gastrointestinal inflammatory biomarkers
Figure
1. (a) Exploded view of the capsule-like gas sensor module, (b) optical image of the gas
sensor with the pcb, and
(c) optical image of the encapsulated module.
Figure
2. Circuit diagram of the electrochemical gas sensor driving unit
Figure
3. In vivo continuous no monitoring in (a) ischemia/reperfusion injury compartment, (b)
healthy compartment, and
(c) control compartment.
