Electrogastrogram
- Gastric Dysrhythmia Testing
Device 
The 3CPM Company’s Electrogastrogram (EGG)
Machine is an analysis system that records, stores, displays and
prints the myoelectric signals from the stomach as an aid to diagnosis
of various gastric motility disorders.
Optimum use of this device requires a basic
familiarity with the published literature which describes typical EGG
patterns commonly encountered in clinical practice with specific
patient groups and related interpretative techniques. An appendix is
provided at the end of this manual, however, which illustrates the
data and printed displays produced by this device. The setting up of
the equipment is described in the section on
equipment setup.
The filter characteristics of the amplifier
allow those biological signals with approximate frequency ranges from
1 to 15 cycles per minute (cpm) to pass through for recording and
digitization. Two channels of data are recorded during the session.
One of these is the Electrogastrogram signal itself; the other channel records
respiratory rates. This respiratory recording channel is used to help
identify artifact in the EGG signal caused by movement, deep
breathing, etc.
The analog signals recorded from the EGG skin
electrodes and the respiratory belt are amplified, filtered and fed
into four cables. The cables are connected to a computer which has
been equipped with an analog to digital (A/D) converter for
digitization of the Electrogastrogram signal.
The data file that is created during the A/D
conversion of the EGG signal undergoes Fourier transform (FFT), an
analysis of the frequencies contained in the EGG signal and a running
spectral analysis (RSA). A plot of the RSA and calculation of the
percentage of power in selected frequency bands are reports produced
by the Electrogastrogram analysis system.
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These Electrogastrogram datum are presented in four major
frequency ranges:
-
normal (2.5 to 3.75 cpm)
-
bradygastria (1.0 - 2.5 cpm)
-
tachygastria (3.75 - 10.0 cpm)
-
duodenal-respiratory (10.0 - 15 cpm)
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The data in these ranges are described in four
ways:
1.
the raw power (log mV2)
2.
the percentage distribution of the power in the specific ranges
described above
3.
the ratio of power based on postprandial to preprandial power
4.
the RSA of the Electrogastrogram recording presented in a pseudo-3-D format
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