The objective of the EGG cyberzine is to present a comprehensive overview of electrogastrography from methodological point of view, explain the quantitative information that can be extracted from EGG, and discuss clinical studies related to gastric electrical activity.
The cyberzine is maintained by:Dr. Martin P. Mintchev Department of Electrical and Computer Engineering University of Calgary Calgary, Alberta, Canada T2N 1N4. Phone: (403) 220-5309; Fax: (403) 282-6855 e-mail: firstname.lastname@example.org
Clinical and methodological aspects of electrogastrography that are discussed in this Cyberzine are supervised by Dr. Kenneth L. Bowes, Professor of Surgery at the University of Alberta, technical and methodological aspects are supervised by Dr. Martin P. Mintchev, Professor of Electrical and Computer Engineering, University of Calgary, and Adjunct Professor of Surgery (University of Alberta).
Researchers are encouraged to submit to the above address materials related to electrogastrography which they consider important. The documents should be saved as files on a 3.5" diskette using MS Word for Windows (version 6.0 or lower). Please provide your figures in .GIF format. Note that tables and formulae might not appear as desired. Try to avoid figures and formulae as much as you can. All submissions will be reviewed and either completely accepted or completely rejected. In general, all contributions will be accepted but unethical, repetitive or offensive submissions will be excluded. The submitted diskettes are non-refundable. You will be able to check whether your contribution is accepted by browsing this EGG Cyberzine.
This Cyberzine was not designed to be a medical advisory of any sort. For medical advise please refer to your doctor.
The material in this Cyberzine is copyrighted. Any reproduction without permission of the editors is illegal. Although the format of this information is electronic, the cyberzine is subjected to the same copyright regulations that cover any other form of publication.
<C> Copyright Martin P. Mintchev/ Kenneth L. Bowes, 1995
FIGURE A. Combined 4-minute recording of internal and cutaneous gastric electrical activity: Channels 1-3 are short distance bipolar (SDB) recordings with implanted electrodes; Channels 4-5 are long distance bipolar (LDB) recordings with implanted electrodes; Channels 6-8 are electrogastrographic (EGG) recordings;
FIGURE B. Three-dimensional plots of 1-hour electrogastrographic signal (2 channels).
FIGURE C. Standard electrode positions for electrogastrographic recordings.
Electrogastrography is the cutaneous recording of gastric electrical activity.
The electrical activity of the stomach, its interrelations with gastric motor function, and its role in gastric motility disorders has been the research focus of many scientists in this century. The works of Alvarez (1, 2, 3), Alvarez and Mahoney (4, 5) and others (6, 7, 8) in the early 1920s paved the way for decades of research in this area.
While a great deal of attention has been directed at understanding the electrophysiological processes in the stomach in vitro (outside the living organism), significant efforts have also been devoted to studying these phenomena in vivo (within the living organism).
Gastric electrical abnormalities recorded in vivo with electrodes implanted on the stomach wall can be related to certain gastric motility disorders (9, 10, 11, 12). However, such techniques are rarely used because they are invasive and uncomfortable (10, 11, 12).
Cutaneous recordings of gastric eletrical activity (GEA), known as electrogastrography (EGG), would seem to be an avenue for the non-invasive assessment of gastric motility. Although Alvarez recorded electrogastrographic signals in 1921 (2), only recently has the technique shown practical promise. EGG has been introduced into several gastrointestinal motility laboratories in the U.S.A., Canada, the Netherlands, Great Britain, Germany, France, Japan and Australia. Unfortunately, the diagnostic value of this method is still in question and much new knowledge is required before clinical disorders can be related to EGG signals with any certainty (10).
(this section is under development)
1. Electrical Phenomena in the Human Stomach (by Martin Mintchev and Kenneth Bowes)
2. Modeling of Gastric Electrical Activity (by Martin Mintchev)
3. Amplification of Gastric Electrical Signals (by Martin Mintchev)
4. Methods to Assess Gastric Electrical Activity (by Martin Mintchev, Jack Kingma and Kenneth Bowes)
5. Accuracy of EGG (by Martin Mintchev, Jack Kingma and Kenneth Bowes)
6. Derivation of an Objective Method to Assess EGG (by Martin Mintchev and Kenneth Bowes)