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Electromyographic detection of
gastrointestinal smooth muscle
activity in rest and stress condition
1Gáspár
R, 1Szűcs K, 2Grosz Gy, 1Ducza E, 1Seres AB, 1Tiszai Z
1Department of Pharmacodynamics and Biopharmacy, Faculty of
Pharmacy, University of Szeged, Szeged, Hungary
2MDE GmbH, Walldorf, Germany
Smooth muscle electromyography
(SMEMG)
• Recording electrical signals of smooth muscles
in vivo
• Requirements:
electrodes
amplifier
software and hardware to record, filter
and analyse
FFT analysis of different bioelectrical signals
Gil Y et al., Sensors 2012. 12(8), 10381-10394.
Obioha CB et al., Journal of Gastroenterology and Hepatology Research
2013. 2(4), 513-519 .
Ushiyama J et al., Journal of Applied Physiology 2010. 109 (4), 1086-1095.
Aim
• Characterization and differentiation of the
electrical signals in different sections of GI tract
with smooth muscle electromyography in rats
• Detection of stress response via GI tract
Methods
• Animals
– male SPRD rats (260-300 g)
–
–
–
–
–
Ketamine-xylazine (36 -4 mg/kg) anaesthesia
Partial GI resection (stomach, small or large intestine left)
Jugular vein cannulation (neostigmine - 20 μg/kg or atropine - 300 μg/kg iv.)
Laparotomy for sensor placements
Stress: immobilization
• Sensors
–
–
–
–
Filament electrode pair – organs wall (stomach, ileum, cecum)
Disk electrode pair – s.c. abdominal surface
Strain gauge – organs surface (force-displacement)
Wire connection to computer
• Software
– S.P.E.L. Advanced ISOSYS Data Acquisition System (Experimetria Ltd.)
– Band-pass filter: 0-30 CPM, 7 order, Bessel type
– Fast Fourier Transformation
• Record
– 60 min for characterization
– 30 min for pharmacological or stress response
Experimental setup of sensors
(cecum)
Filament electrode pair
(cecal wall)
Strain gauge (cecal surface)
Disc electrode pair
(s.c., abdominal surface)
Stomach
Primary curves
Filament
Disc
SG
500 s
FFT analysis
CPM patterns of GI tract after FFT analysis in rats
ceF
ceD
stoF
stoD
ileF
ileD
PsD max
10000
8000
6000
4000
2000
1000
800
600
400
200
30
20
10
0
1
2
3
4
5 15
CPM
20
25
30
N
eo
st
ce
A
tr
ce
ce
N
eo
st
ile
A
tr
ile
ile
25
24
23
22
21
20
5
4
3
2
1
0
st sto
o
N
eo
s
st t
o
A
tr
CPM
Effects of neostigmine and atropine on CPM
values of GI tract in rats
200
250
200
150
**
**
100
100
*
50
50
N
G
tr
.S
A
eo
s
t.
S
G
to
D
tr
.s
A
to
D
t.
s
eo
s
N
tr
.s
A
t.
s
eo
s
to
F
0
to
F
0
N
150
Changes of AUC in % of the control
PsD max changes in % of the control
Effects of neostigmine and atropine on gastric
PsDmax values after small and large intestine
resection in rats
Changes of AUC in % of the control
stomach
250
2
r =0.84
200
150
100
50
0
0
100
200
300
PsD max changes in % of the control
Changes of AUC in % of the control
Changes of AUC in % of the control
Correlation between changes in PsDmax and AUC
values
250
ileum
250
200
150
100
50
0
0
100
r2=0.77
200
150
100
50
0
100
200
300
PsD max changes in % of the control
cecum
0
r2=0.84
200
300
PsD max changes in % of the control
Experimental setup of sensors
(intact GI tract)
Strain gauge (stomach)
Strain gauge (ileum)
Strain gauge (cecum)
Disc electrode pair
(s.c., abdominal surface)
A
tr
.S
G
G
t.
S
eo
s
N
A
eo
s
N
A
tr
.S
G
G
N
eo
s
t.
S
eD
tr
.c
A
t.
c
eD
**
eo
s
N
PsD max changes in % of the control
***
200
180
160
140
120
100
80
60
40
20
0
Changes of AUC in % of the control
large intestine (cecum)
1-3 CPM
200
180
160
140
120
100
80
60
40
20
0
***
**
tr
.i
le
D
G
tr
.S
A
N
eo
s
t.
S
G
to
D
tr
.s
A
N
eo
s
t.
s
to
D
**
le
D
**
200
180
160
140
120
100
80
60
40
20
0
t.
i
200
180
160
140
120
100
80
60
40
20
0
PsD max changes in % of the control
200
180
160
140
120
100
80
60
40
20
0
small intestine (ileum)
20-26 CPM
200
180
160
140
120
100
80
60
40
20
0
Changes of AUC in % of the control
stomach
3-5 CPM
Changes of AUC in % of the control
PsD max changes in % of the control
Effects of neostigmine and atropine on GI EMG signals in
intact rats
Corticosterone levels before and after stress in rats
(individual results)
500
450
350
300
250
200
150
100
50
s1
0
11
s1
1
12
s1
2
10
9
s9
8
s8
7
s7
6
s6
5
s5
4
s4
3
s3
2
s2
0
1
s1
corticosterone (ng/ml)
400
Corticosterone levels before and after stress in rats
(average)
***
300
200
100
st
re
s
s
0
co
nt
ro
l
corticosterone (ng/ml)
400
C
ae
c
um
Ile
um
ac
h
St
om
PsDm ax changes as % of the control
Changes in electric activity after stress
300
200
100
0
Conclusions
• The electrical signals can be distinguished
among stomach, small intestine (ileum) and
large intestine (cecum) by FFT.
• The place of origin of the signals can be
determined by CPM value, while the intensity
of the signals are described by the peak of
PsDmax.
• The changes in electrical signals show strong
correlation with the changes in mechanical
contractions.
• The stress response can be measured by the
detection of GI electric signals
Application: research, diagnostics, sport sciences
Acknowledgments
• PIAC_13-1-2013-0201 project
Ministry of National Development, Hungarian Government
• Zoltánné Csiszár
• Kálmánné Csíkszentimrei
• Veronika Verseghy