Electrogastrogram

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The invention of the 3CPM Electrogastrogram'

This noninvasive, user-friendly system was tested on over 1,000 patients presenting with difficult symptomatology and also in animal drug research. The device’s validity and reliability liken its potential to the extensively-used electrocardiogram (EKG). After testing, 3CPM obtained regulatory clearance from the FDA in 1998, then US patent and copyright protection. The initial US-based product launch further defined the following clinical categories: tachygastria, bradygastria, and reflux-related GERD+ Dyspepsia, which affects millions more in the population than previously identified. The incorporation of population-based normal values, against which disease states may be distinguished, is what makes 3CPM’s EGG unique. No other device in the field is able to make this claim.

The most recent developments for 3CPM’s EGG include: • the creation of new predictive conformational statistical diagnostic methodologies, based upon the strength and reproducibility of the 3CPM (3 cycles per minute)

• the disease-related threshold software, known as the EGG GMAT®, which defines both specific gastroparesis subtypes and the predictability of therapy’s success for this disease.

About the 3CPM Company ® 3CPM Company was formed in January 1998 to exploit the proprietary Electrogastrogram (EGG) technology developed by one of its founders, Kenneth Koch, MD, and to capitalize on the resulting market opportunity.

About the 3CPM Company ® 3CPM Company was formed in January 1998 to exploit the proprietary Electrogastrogram (EGG) technology developed by one of its founders, Kenneth Koch, MD, and to capitalize on the resulting market opportunity.

Dr. Koch is the Section Head of Section on Gastroenterology at Wake Forest University. As a world-renowned expert in diagnostic gastroenterology, Dr. Koch developed the initial EGG and associated EGGSAS software for clinical use. The 3CPM® device detects, records, and analyzes the electrical activity of the stomach to diagnose the gastric myoelectrical activity (GMA) and abnormalities in a quick, accurate, and reproducible manner. These detected abnormalities are associated with a number of conditions that afflict millions worldwide. 3CPM® is fortunate to have one of the world’s leading experts in this emerging field as a founder, director and officer of the Company. 3CPM was co-founded in 1998 by a seasoned medical device President/CEO and a CFO, both of whom had had several successful start ups to their credit. In 2001, 3CPM brought Mark D. Noar, MD, an established user and recognized gastroenterologist, onto the board.

Dr. Noar was appointed Board Chairman and CEO. Under his guidance, 3CPM has continued to advance and mature with the development of:

• research-specific software platforms for animal and human research,

• software tools to allow automatic detection and correction of hardware and software errors,

• companion software programs to facilitate device use in large research-based projects with the National Institutes of Health (NIH) and the pharmaceutical industry.

Technology[edit]

T he 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.(See user manual)

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.

These detected abnormalities are associated with a number of conditions that afflict millions worldwide. 3CPM® is fortunate to have one of the world’s leading experts in this emerging field as a founder, director and officer of the Company. 3CPM was co-founded in 1998 by a seasoned medical device President/CEO and a CFO, both of whom had had several successful start ups to their credit. In 2001, 3CPM brought Mark D. Noar, MD, an established user and recognized gastroenterologist, onto the board. (Source)

The filter characteristics of the amplifier allow 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 channel supplies the Electrogastrogram signal; 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. The 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 cp

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. (Read more)

An electrogastrogram (EGG) is a graphic produced by an electrogastrograph, which records the electrical signals that travel through the stomach muscles and control the muscles' contractions. An electrogastroenterogram (or gastroenterogram) is a similar procedure, which writes down electric signals not only from the stomach, but also from intestines.

These names are made of different parts: electro, because it is related to electrical activity, gastro, Greek for stomach, entero, Greek for intestines, gram, a Greek root meaning "to write".

An electrogastrogram and a gastroenterogram are similar in principle to an electrocardiogram (ECG) in that sensors on the skin detect electrical signals indicative of muscular activity within. Where the electrocardiogram detects muscular activity in various regions of the heart, the electrogastrogram detects the wave-like contractions of the stomach (peristalsis).

Walter C. Alvarez pioneered early studies of electrogastrography in 1921–22.[1]

Physiological basis[edit]

Motility of GI tract results from coordinated contractions of smooth muscle, which in turn derive from two basic patterns of electrical activity across the membranes of smooth muscle cells—slow waves and action potentials.[2] Slow waves are initiated by pacemakers—the interstitial cells of Cajal (ICC). Slow wave frequency varies in the different organs of the GI tract and is characteristic for that organ. They set the maximum frequency at which the muscle can contract:

  • stomach – about 3 waves in a minute,
  • duodenum – about 12 waves in a minute,
  • jejunum – about 11 waves in a minute.[3]
  • ileum – about 8 waves in a minute,
  • rectum – about 17 waves in a minute.[4]

The electrical activity of the GI tract can be subdivided into two categories: electrical control activity (ECA) and electrical response activity (ERA). ECA is characterized by regularly recurring electrical potentials, originating in the gastric pacemaker located in the body of stomach. The slow waves are not a direct reason of peristalsis of a GI tract, but a correlation between deviations of slow waves from norm and motility abnormalities however is proved.[5]

Cutaneous electrogastrography[edit]

Electrogastrogram can be made from the gastrointestinal mucosa, serosa, or skin surface. The cutaneous electrogastrography provides an indirect representation of the electrical activity but it is much easier and therefore cutaneous electrogastrography has been used most frequently.

Several EGG signals are recorded from various standardized positions on the abdominal wall and to select the one with the highest amplitude for further analysis. For this purpose usually use three or more Ag-AgCl electrodes.[6] Recordings are made both fasting (usually 30 minutes) and after a meal (usually 60 minutes) with the patient lying quietly. Deviations from the normal frequency may be referred to as bradygastria or tachygastria.

In normal individuals the power of the electrical signals increases after the meal. In patients with abnormalities of stomach motility, the rhythm often is irregular or there is no postprandial increase in electrical power.

Bradygastria, normogastria and tachygastria[edit]

Terms bradygastria and tachygastria are used at the description of deviations of frequency of an electric signal from slow waves are initiated by pacemaker in the stomach from normal frequency of 3 cycles per minute.

A bradygastria is defined, how decreased rate of electrical activity in the stomach, as less than 2 cycles per minute for at least 1 minute.

A tachygastria is defined, how increased rate of electrical activity in the stomach, as more than 4 cycles per minute for at least 1 minute.

A bradygastria and tachygastria may be associated with nausea, gastroparesis, irritable bowel syndrome, and functional dyspepsia.[7]

CPT and HCPCS codes for electrogastrography[edit]

There are following Current Procedural Terminology (CPT) and Healthcare Common Procedure Coding System (HCPCS) codes (maintained by the American Medical Association) for cutaneous electrogastrography:[8]

CPT/HCPCS-code Procedure
91132 Electrogastrography, diagnostic, transcutaneous
91133 Electrogastrography, diagnostic, transcutaneous; with provocative testing

Electrogastroenterography[edit]

An electrogastroenterography (EGEG) is based that different organs of a GI tract give different frequency slow wave.

Organ of gastrointestinal tract Investigated range (Hz) Frequency number (i)
Large intestine 0.01 – 0.03 5
Stomach 0.03 – 0.07 1
Ileum 0.07 – 0.13 4
Jejunum 0.13 – 0.18 3
Duodenum 0.18 – 0.25 2

EGEG electrodes are as much as possible removed from a stomach and an intestines—usually three electrodes are placed on the extremities. It allows to receive stabler and comparable results.

Computer analysis[edit]

3D graph of a human gastroenterogramm: electrical signals from GI smooth muscle (in µV) on the vertical y-axis; from left to right on the x-axis: large intestine, stomach, ileum, jejunum, duodenum. The time (in minutes) is drawn on the z-axis.

An electrogastroenterography analysis program calculate[9]

  • P(i) – capacities of an electric signal separately from each of organ of GI tract in corresponding range of frequencies:

where S(n) – spectral components in the rank from sti to fini (defined by received investigated range of this organ of GI tract) by Discrete Fourier transform of the electric signal from GI tract.

  • PS – the general (total) capacity of an electric signal from five parts of GI tract:
  • P(i)/PS – the relative electric activity.
  • Kritm(i) – rhythm factor

EGEG parameters for normal patients:[9]

Organ of gastrointestinal tract Electric activity P(i)/PS Rhythm factor Kritm(i) P(i)/P(i+1)
Stomach 22.4±11.2 4.85±2.1 10.4±5.7
Duodenum 2.1±1.2 0.9±0.5 0.6±0.3
Jejunum 3.35±1.65 3.43±1.5 0.4±0.2
Ileum 8.08±4.01 4.99±2.5 0.13±0.08
Large intestine 64.04±32.01 22.85±9.8  —

Psychological applications[edit]

Psychologists have performed psychophysiological studies to see what happens in the body during affective experiences. Electrogastrograms have recently been used to test physiological arousal, which was already determined by measures such as heart rate, electrodermal skin responses, and changes in hormone levels in saliva.[10]

Currently, a pattern of interest to psychologists is an increase in bradygastria, which is when electrical activity in the stomach drops to below 2 cpm resulting in a slower stomach rhythm, when exposed to disgusting stimuli, which may be a precursor to nausea and vomiting, both physiological responses to disgust.[11] In this study, the presence of bradygastria was able to predict trait and state disgust, which no other physiological measure used in the study was able to detect.[11] This abnormal myoelectrical activity is usually combined with other precursors to nausea and vomiting, such as increased salivary production, which further supports the idea that these rhythms show early signs of nausea and vomiting. These reactions are viewed as a way in which the body rejects unhealthy foods,[11] which is linked with the view that disgust is an evolutionary adaptation to help humans avoid consuming toxic substances.[11][12]

During sham feeding sessions of both appetizing and unappetizing foods, 3 cycles per minute (cpm) power was measured. During the sham feeding of appetizing foods, 3cpm power increased. This increase was not reported in the sham feeding of unappetizing foods.[12] The researchers concluded that the presence of this pattern seems to mark the beginning of the body preparing for digestion, and the absence of this pattern in the disgust condition could indicate that the body is readying to reject the food.[12] The increase of 3cpm power is also linked with increased saliva and digestive juice production, all of which support the idea that this reflex, called the cephalic-vagal reflex,[12] is the precursor of digestion. The differential response to appetizing and unappetizing foods suggest that the body uses disgust as a cue to whether a food is good to eat and responds accordingly.

Another emotion with a bodily effect that can be measured by EGG is that of stress. When the body is stressed and engages in the fight-or-flight response, blood flow is directed to the muscles in the arms and legs and away from the digestive system. This loss of blood flow slows the digestive system, and this slowing can be seen on the EGG.[13] However, this response can vary from person to person and situation to situation.[13]

All of these examples are part of a larger theory of a brain–gut connection. This theory states that the vagus nerve provides a direct link between the brain and the gut so that emotions can affect stomach rhythms and vice versa.[12][13] This idea originated in the mid-1800s when Alexis St. Martin, a man with a gunshot-induced fistula in his abdomen, experienced lower secretions of digestive juices and a slower stomach emptying when he was upset.[13] In this case, the emotions St. Martin was feeling affected his physiological reaction, but the reverse can also be true. In a study with Crohn's disease patients where patients and unaffected controls watched happy, frightening, disgusting, and saddening films, patients with active Crohn's disease had more responsive EGG (a greater physiological response) and reported feeling more aroused when feeling the negative emotions of disgust or sadness.[14] This leads researchers to believe that increased physiological activation can influence increased experience of emotions.[14] Another study published in 1943 that studied the fistulated man Tom discovered that if "Tom was fearful or depressed his gastic activity decreased but when he was angry or hostile his gastric activity increased".[13] This finding is contrasted by an EGG study by Ercolani et al. who had subjects perform either difficult or easy mental arithmetic or puzzles. They found that new tasks slowed down the myoelectrical activity of the stomach, suggesting that stress tends to impede gastric activity and that this can be picked up on an EGG.[15] While there is still much research to be done on the brain-gut connection, research thus far has indeed shown that your stomach does indeed churn differently when you are emotionally aroused,[16] and this could be the basis of the gut feeling that many people describe experiencing.

Gender differences[edit]

In recent years, some research has been done about gender differences in the perception and experience of disgust. One such study, upon presenting both male and female subjects with video clips designed to trigger disgust and found that although women reported feeling more disgust than men at these stimuli, the physiological responses did not show much difference.[10] This could mean that, psychologically, women are more sensitive to disgust than men; however this assertion cannot be supported with physiological data.[10] More research has to be done in this area to see if there are gender differences in the psychophysiological experience of disgust.

Unsolved problems[edit]

There are some limitations to the use of electrogastroenterography:

  • the absence of a standard technique of performance peripheral electrogastroenterography,
  • the absence of standard norms of electrophysiological parameters of bioelectric activity in the GT tract,
  • the impossibility of an estimation of change of motility abnormalities during the concrete moments of time on local sites of GI tract.

Other advances[edit]

Clinical applications[edit]

Electrogastrography or gastroenterography used when a patient is suspected of having a motility disorder, which can be shown, as recurrent nausea and vomiting, signs that the stomach is not emptying food normally. The clinical use of electrogastrography has been most widely evaluated in patients with gastroparesis and functional dyspepsia.

Sources[edit]

References[edit]

  1. ^ Alvarez W. C. (April 15, 1922). "The electrogastrogram and what it shows". J Am Med Assoc. 78 (15): 1116–19. doi:10.1001/jama.1922.02640680020008. 
  2. ^ Bowen R. (November 23, 1996). "Electrophysiology of Gastrointestinal Smooth Muscle". Retrieved February 12, 2008. 
  3. ^ Waldhausen, JH; Shaffrey, ME; Skenderis Bs, 2nd; Jones, RS; Schirmer, BD (June 1990). "Gastrointestinal myoelectric and clinical patterns of recovery after laparotomy". Ann. Surg. 211 (6): 777–84; discussion 785. doi:10.1097/00000658-199006000-00018. PMC 1358137Freely accessible. PMID 2357140. 
  4. ^ Ginzburg, G. V.; Costoff, A. "3: Gastrointestinal Physiology. Gastrointestinal Motility". GI Smooth Muscle Electrophysiology: Slow Waves (Basal Electric Rhythm). p. 5. 
  5. ^ Parkman HP, Hasler WL, Barnett JL, Eaker EY; Hasler; Barnett; Eaker; American Motility Society Clinical GI Motility Testing Task Force (April 2003). "Electrogastrography: a document prepared by the gastric section of the American Motility Society Clinical GI Motility Testing Task Force". Neurogastroenterol. Motil. 15 (2): 89–102. doi:10.1046/j.1365-2982.2003.00396.x. PMID 12680908. 
  6. ^ Stendal, Charlotte (1997). Practical guide to gastrointestinal function testing. Oxford: Blackwell Science. ISBN 0-632-04918-9. 
  7. ^ MediLexicon. Definitions of "Bradygastria" and "Tachygastria".
  8. ^ Federal Register. Vol. 72, No. 148 /Thursday, August 2, 2007/ Proposed Rules, 42997.
  9. ^ a b Stupin V. A., et al. Peripheral Electrogastroenterography in Clinical Practice // Лечащий Врач.-2005.-№ 2.-С. 60-62 (Russian).
  10. ^ a b c Rohrmann, Sonja; Hopp, Henrik, Quirin, Markus (2008). "Gender differences in psychophysiological responses to disgust". Journal of Psychophysiology. 22 (2): 65–75. doi:10.1027/0269-8803.22.2.65. 
  11. ^ a b c d Meissner, Karin; Muth, Eric R.; Herbert, Beate M. (1 Oct 2010). "Bradygastic activity of the stomach predicts disgust sensitivity and perceived disgust intensity". Biological Psychology. 86 (1): 9–16. doi:10.1016/j.biopsycho.2010.09.014. PMID 20888886.  Check date values in: |year= / |date= mismatch (help)
  12. ^ a b c d e Stern, Robert M.; Jokerst, M.D.; Levine, M.E.; Koch, K.L. (April 2001). "The stomach's response to unappetizing food: cephalic-vagal effects on gastric myoelectric activity". Neurogastroenterology and Motility. 13 (2): 151–154. doi:10.1046/j.1365-2982.2001.00250.x. PMID 11298993. 
  13. ^ a b c d e Stern, Robert M.; Koch, Kenneth L; Levine, Max E.; Muth, Eric R. (2007). Cacioppo, John T.; Tassinary, Louis G.; Berntson, Gary G., eds. Handbook of Psychophysiology (3rd ed.). Cambridge: Cambridge University Press. pp. 211–230. 
  14. ^ a b Vianna, Eduardo P.M.; Weinstock, Joel, Elliot, David, Summers, Robert, Tranel, Daniel; Elliott, D; Summers, R; Tranel, D (2006). "Increased feelings with increased body signals". Scan. 1 (1): 37–48. doi:10.1093/scan/nsl005. PMC 2555412Freely accessible. PMID 18985099. 
  15. ^ Ercolani, Mauro; Baldaro, Bruno, Trombini, Giancarlo; Trombini, Giancarlo (1989). "Effects of Two Tasks and Two Levels of Difficulty on Surface Electrogastrograms". Perceptual and Motor Skills. 69 (1): 99–110. doi:10.2466/pms.1989.69.1.99. PMID 2780207. 
  16. ^ Vianna, E.P.M.; Tranel, D. (2006). "Gastric Myoelectrical Activity as an Index of Emotional Arousal". International Journal of Psychophysiology. 61 (1): 70–76. doi:10.1016/j.ijpsycho.2005.10.019. PMID 16403424. 
  17. ^ Tokmakçi M (August 2007). "Analysis of the electrogastrogram using discrete wavelet transform and statistical methods to detect gastric dysrhythmia". J Med Syst. 31 (4): 295–302. doi:10.1007/s10916-007-9069-9. PMID 17685154. 
  18. ^ Jung E.S., et al. Design and Implementation of the Telemetry Capsule for Measuring of Electrogastrography. Proceedings of the 24th IASTED international conference on Biomedical engineering. Innsbruck, Austria, pp. 209-213, 2006, ISBN 0-88986-578-7.