Role of sham feeding in postprandial changes of gastric myoelectrical activity

The aim of this study was to evaluate the role of sham feeding in postprandial changes of gastric myoelectrical activity. Eighteen asymptomatic healthy volunteers (10 men, 8 women; mean age: 31), with no history of gastrointestinal disease were studied. Gastric myoelectrical activity was recorded for 30 min at baseline, 30 min after sham feeding, and 1 hr after eating, using surface electrogastrography. The electrogastrogram (EGG) was analyzed by spectral analysis. It was found that the changes of postprandial EGG parameters were significantly correlated with those after sham feeding (EGG dominant power: r = 0.6, P < 0.01; dominant frequency: r = 0.8, P < 0.001; percentage of regular slow waves: r = 0.7, P < 0.003). We concluded that intrinsic gastric electrical activity can be altered by sham feeding and the cephalic phase of digestion plays an important role in the postprandial response of gastric myoelectrical activity.     

Gastric myoelectrical activity in patients with gastric outlet obstruction and idiopathic gastroparesis

OBJECTIVE: The cause of gastroparesis may be uncertain in some patients. Mechanical obstruction of the stomach or duodenum should be excluded in patients with idiopathic gastroparesis. The objective of this study was to compare gastric myoelectrical activity in patients with idiopathic gastroparesis with that of patients with gastroparesis due to mechanical obstruction of the stomach or duodenum. METHODS: Electrogastrography techniques were used to record gastric myoelectrical activity in 20 patients with idiopathic gastroparesis and in nine patients with gastroparesis secondary to gastric outlet obstruction. Four of these nine patients initially were thought to have idiopathic gastroparesis. Electrogastrograms (EGGs) were recorded from 29 healthy subjects who served as controls. EGGs were recorded for 20-30 min 2 h after a standard 200-Kcal meal and were analyzed visually and by computer. RESULTS: Patients with gastroparesis due to outlet obstruction had high-amplitude and excessively regular 3-cycles-per-minute (cpm) EGG patterns, whereas patients with idiopathic gastroparesis had primarily 1- to 2-cpm patterns and little 3-cpm EGG activity. The percentage of total EGG power in the 3-cpm range was approximately 50% in patients with gastric outlet obstruction compared with 20% in patients with idiopathic gastroparesis (p < 0.001). The percentage of EGG power in the normal 3-cpm range was greater in the obstructed patients (50%) than in the healthy controls (35%; p < 0.052). CONCLUSIONS: Gastric myoelectrical patterns recorded in the EGG distinguish mechanical and idiopathic causes of gastroparesis and may be useful in evaluating patients with nausea, vomiting, and gastroparesis of unknown cause.     

Impaired postprandial gastric slow waves in patients with functional dyspepsia

The aim of this study was to investigate gastric myoelectrical activity in patients with functional dyspepsia. Thirteen healthy subjects and 14 patients with functional dyspepsia participated in the study. The electrogastrogram (EGG) recording was made in each subject for 30 min in the fasting state and 120 min after a standard test meal of 475 calories. Spectral analysis methods were applied to derive quantitative EGG parameters. There was no difference in the EGG between the patients and controls in the fasting state. However, abnormalities in the postprandial EGG were found in the patients. The percentage of 2-4 cpm waves was significantly lower (74.4+/-4.0% vs 85.7+/-1.6%, P < 0.03) and the postprandial increase in EGG dominant power was significantly less (-0.52+/-0.92 dB vs 2.24+/-0.88 dB, P < 0.03) in patients than in controls. It was also found that the percentage of postprandial 2-4 cpm waves could be used to differentiate the patients with functional dyspepsia from the healthy controls with a specificity of 100% and a sensitivity of 43%. It was concluded that a subset of patients with functional dyspepsia have impaired gastric myoelectrical activity in the fed state.     

Gastric emptying and antral myoelectrical activity in chronic alcoholics with dyspepsia

BACKGROUND/AIMS: Chronic alcoholism is known to effect gastric motor activity. An association between gastric motility disorders and abnormal myoelectrical activity has been observed in various gastrointestinal and extra-intestinal diseases. The aim of this study was to investigate the effect of chronic alcoholism on gastric emptying and antral myoelectrical activity. METHODOLOGY: Electrogastrography (EGG) was performed on 20 chronic alcoholics with chronic dyspepsia using a pair of electrodes sonographically placed on the skin overlying the gastric antrum. After an overnight fast, patients were tested over a period of one hour in the a) fasting and b) fed state, after ingestion of a 370 kcal liquid-solid test meal. The following EGG parameters were determined: dominant frequency (DF (cpm); DF (%) in the normal range (2-4 cpm); bradygastria (<2 cpm); tachygastria (4-10 cpm); dominant frequency instability coefficient (DFIC), and postprandial to fasting power ratio (PR). The data were correlated with results obtained from 20 controls matched for age and sex. In 18 alcoholics, the EGG data were compared to the percentage of radionuclides (liquid phase labeled with 99m Tc colloid) remaining in the stomach after 60 minutes (%) (gamma camera system). Moreover, for the alcoholics, various parameters such as ethanol consumption, and gastrointestinal symptoms were determined and related to EGG values and scintigraphy. RESULTS: About 50% of the alcoholics showed delayed gastric emptying compared to normal values previously reported (t 60 values: >68%). In opposite to scintigraphy, the alcoholics did not exhibit abnormalities in antral myoelectrical activity. They had significantly decreased bradygastria measures compared to controls (p<0.05). The scintigraphic t 60 values did not correlate either with EGG values or with dyspepsia and clinical parameters. EGG values did not correlate with dyspepsia. However, increased preprandial DF was significantly correlated with ethanol consumption. CONCLUSIONS: Chronic alcoholism induces a disturbance of gastric emptying, probably resulting from toxic damage of the gastrointestinal smooth muscles. Disturbances in antral myoelectrical activity were not found.     

Gastric myoelectrical activity in patients with diabetes. Role of glucose control and autonomic nerve function

OBJECTIVE: Gastric myoelectrical activity was studied in diabetic patients using electrogastrography (EGG) to elucidate the relationship between glucose control, diabetic autonomic neuropathy (AN), and gastrointestinal motility. RESEARCH DESIGN AND METHODS: Cutaneous EGG was recorded during 1 h of fasting and 1 h after the ingestion of a standard meal in 57 diabetic patients and 10 healthy subjects. EGG was measured in 12 diabetic patients after glycemic control for 4 weeks. Diabetic patients were also studied with respect to the presence of gastrointestinal symptoms and AN. RESULTS: The percentage of dominant electrical frequency (DF) in normal range (the percentage ratio between the power at 2.4-3.6 cycles/min [cpm] and at 1-10 cpm) was significantly lower in patients with AN than in either the control subjects or the patients without AN (P < 0.01). The dominant frequency instability coefficient (DFIC) was significantly higher in patients with and without AN than in the control subjects (P < 0.01). The postprandial-to-fasting power ratio (PR) was the lowest in patients with AN (P < 0.01). Multiple regression analysis revealed that HbA1c levels were independently associated with the DFIC (R2 = 0.099, P = 0.0170) and that AN and HbA1c levels were independently associated with the PR (R2 = 0.378, P < 0.0001) in diabetic patients. The percentage of normal DF increased and the DFIC decreased significantly after glycemic control in 12 diabetic patients (P = 0.0409; P = 0.0096, respectively). CONCLUSIONS: There appears to be an association between improvement in gastric myoelectrical activity and autonomic nerve function. Abnormalities of gastric myoelectrical activity may be partly ameliorated via the improvement of autonomic nerve function, which accompanies glycemic control.     

Gastric myoelectrical activity in healthy children and children with functional dyspepsia

The aim of this study was to investigate abnormalities in pediatric patients with functional dyspepsia. Fifteen symptomatic pediatric patients diagnosed with functional dyspepsia and 17 aged-matched healthy controls were studied. Gastric myoelectrical activity was recorded using surface electrogastrography for 1 hr in the fasting state and 1 hr after a test meal. It was found that, in comparison with the controls, the children with functional dyspepsia had a lower percentage of 2- to 4-cpm slow waves in both fasting state (66.0+/-4.7% vs 79.7+/-3.1%, P < 0.07) and fed state (72.4+/-5.4% vs 85.0+/-2.9%, P < 0.04), and a significantly higher instability of the dominant frequency in both fasting state (0.50+/-0.05 vs 0.31+/-0.04, P < 0.01) and fed state (0.39+/-0.05 vs 0.25+/-0.03, P < 0.05). It was also found the postprandial increase in EGG dominant power in the patients was inversely correlated with the total symptom score (r = 0.63, P = 0.03). It was concluded that abnormal gastric myoelectrical activity may play a role in the pathogenesis of pediatric functional dyspepsia.     

Gastric myoelectrical activity in patients with cervical spinal cord injury

OBJECTIVE: Dyspeptic symptoms are common in patients with cervical spinal cord injury (SCI). The supraspinal control of sympathetic innervation to the stomach is interrupted in these patients. Gastric emptying has been reported to be delayed in some patients with cervical SCI. Gastric myoelectrical activity is known to regulate gastric motility and is correlated with gastric emptying. The change in gastric myoelectrical activity after cervical SCI is unknown; our aim was to investigate it. METHODS: The study was performed in 12 cervical SCI patients and 14 healthy controls. Gastric myoelectrical activity was recorded using surface electrogastrography for 30 min in the fasting state and 1 h after a standard test meal. Spectral analysis was performed to compute the following parameters from the electrogastrogram; investigated were the percentage of 2-4 cycles/min (cpm) slow waves, the instability coefficient (IC) of the dominant frequency, the postprandial increment of dominant frequency (deltaF), and its power (deltaP). RESULTS: In both fasting and fed states, regular and stable gastric slow waves were observed in both the control group and patients with cervical SCI. The percentage of normal 2-4 cpm slow waves (preprandial, 80.7+/-3.6% vs 91.5+/-3.7%, p > 0.05; postprandial, 82.0+/-4.4% vs 87.2+/-4.2%, p > 0.05) and IC (preprandial, 0.19+/-0.04% vs 0.28+/-0.05%; postprandial, 0.24+/-0.04% vs 0.27+/-0.02%, p > 0.05) were not significantly different between the two groups. The dominant frequency and its power were also similar between the two groups, no matter whether in the fast (frequency, 2.92+/-0.3 vs 2.93+/-0.06 cpm; power, 30.05+/-1.29 vs 29.08+/-1.23 dB, p > 0.05) or fed (frequency, 3.17+/-0.07 vs 3.02+/-0.06 cpm; power, 32.55+/-0.90 vs 32.07+/-1.18 dB,p > 0.05) state. The postprandial response measured by deltaF (0.25+/-0.09 vs 0.09+/-0.07 cpm, p > 0.05) and deltaP (2.52+/-1.10 vs 2.24+/-1.20 dB, p > 0.05) were also similar between the two groups. CONCLUSION: Gastric myoelectrical activity was not altered after cervical SCI.     

Effect of progressive systemic sclerosis on antral myoelectrical activity and gastric emptying

In patients with progressive systemic sclerosis (PSS) suffering from chronic dyspepsia the stomach may be affected by this disease. The objective of this study was to investigate both antral myoelectrical activity and gastric emptying in PSS patients. Electrogastrography (EGG) was performed in 17 PSS patients (16 female, one male, median age 58 years, range 32-74 years) with chronic dyspepsia. After an overnight fast during one hour in the fasting and one hour in the fed state after ingestion of a liquid-solid test meal (370 kcal; liquid phase labeled with 0.5 mCi 99mTc-colloid) antral electrical activity was measured by one pair of electrodes sonographically placed on the skin overlying the gastric antrum. Several EGG parameters including dominant frequency (DF), percentages of DF in the normal range (2-4 cycles per minute [cpm]), bradygastria (< 2 cpm) and tachygastria (4-10 cpm), dominant frequency instability coefficient (DFIC), and postprandial to preprandial power ratio (PR) were calculated. The data were correlated to results obtained in 20 age- and gender-matched healthy subjects. In addition, the data were compared to gastric retention of the radionuclide at 60 min measured by simultaneous scintigraphy. The PSS patients did not reveal electrical disturbances. They even exhibited a significant postprandial decrease in DFIC, bradygastria, and tachygastria (ns) compared to healthy subjects. Over 50% of the PSS patients showed a delayed gastric emptying. However, EGG did not correlate to radioscintigraphy significantly. Our results reflect an absent relationship between antral myoelectrical activity in EGG and gastric emptying. Therefore, electrogastrography is unsuitable to assess gastric involvement in PSS.     

Possibilities of the non-invasive electrogastrography

A non-invasive method for recording the electrical activity of the gastric muscle wall is presented. Electrogastrograms (EGG) with cutaneous electrodes on the abdominal wall were recorded using an original electrogastrograph. High-quality records without cardiac artifacts allowed for identification of waves belonging to the quiescent or activity period of the migrating myoelectric complex (MMC). The amplitude of the waves of the activity period of MMC were almost twice higher than that of the waves of the quiescent period. The wave amplitude immediately after feeding increased two times and a half compared to that during fasting. The high-amplitude waves in the activity periods of MMC and after feeding in the electrogastromyograms (EGMG) of dogs corresponded to bursts of spike potentials with slow potentials, i.e. to intense gastric muscle wall contractions. The method could contribute to the diagnosis of gastric motility disturbances in clinical practice.     

An improved electrogastrographic system in measuring myoelectrical parameters

This study assessed the reliability of an improved electrogastrographic (EGG) system in recording stomach myoelectrical parameters and tried to establish the normal ranges of myoelectricity using this system. The analytical software of the current system mainly included an autoregressive modelling program to compute myoelectrical frequency and power. Forty healthy subjects were enrolled to receive myoelectrical measurement in two consecutively fasting and one postprandial 30 min sessions. The myoelectrical frequencies in both fasting and postprandial sessions were almost three cycles per min (c.p.m.) and showed little variation. The percentage of dominant frequencies (2.5-3.5 c.p.m.) in three sessions was approximately 80% while the computed myoelectrical powers in the first and second fasting sessions exhibited a significant correlation (r=0.84, P<0.001). Meal ingestion increased the myoelectrical powers by 6.8dB compared with the second fasting recording (P< 0.001). The mean variation in myoelectrical amplitude for the ratio of second: first fasting session was 110.3+/-88.8% (16-478%, median 88%). This new EGG system is, indeed, reliable for measuring myoelectrical frequency and power, whereas the interassay of recorded amplitudes appears markedly variable.     

Efficiency and efficacy of the electrogastrogram

The efficiency and efficacy of the electrogastrogram (EGG) involve a few practical factors, including recording length, sample size, and the characteristics of subjects. The aim of this study was to investigate the effect of these factors on the accuracy of EGG analysis. Gastric myoelectrical activity was recorded using electrogastrography in 24 subjects (ages 22-91 years) for 1 hr in the fasting state and 2 hr after a test meal. Computerized spectral analysis was performed to compute EGG parameters, including dominant frequency, dominant power, and the percentage of 2-4 cycles per minute (cpm) slow waves. A parameter called misinterpretation was defined to investigate the effect of recording length. The results were as follows: (1) Using the recording length of 1 hr in each state as a gold standard, the misinterpretation for the recording length of 30 min was 27% for the dominant frequency and 17% for the dominant power. When the recording length was reduced to 15 min, the misinterpretation increased to 61% for the dominant frequency and 38% for the dominant power. (2) With a sample size of 10 subjects and a recording length of 60 min, a statistically significant postprandial increase was observed in the dominant frequency and power, and a trend in the postprandial increase of the regularity of the EGG was noted. When the sample size increased to 24 subjects, a significant postprandial increase was found in all these parameters. (3) None of the EGG parameters exhibited any significant difference between the younger and older subjects or between men and women. In conclusion, a recording length of 30-60 min seems to be appropriate and produces reliable and predictable results. Age and gender do not affect any of the EGG parameters.     

Effect of hyperthyroidism on antral myoelectrical activity, gastric emptying and dyspepsia in man

BACKGROUND/AIMS: The objective of the present study was to investigate the effect of hyperthyroidism on antral myoelectrical activity, gastric emptying and dyspepsia in man. METHODOLOGY: Twenty-three patients with manifest hyperthyroidism and dyspepsia confirmed by a standardized protocol were studied by electrogastrography (EGG). The following EGG parameters were determined: dominant frequency (DF cycles per minute (cpm), DF (%) in the normal range (2-4 cpm)), bradygastria (< 2 cpm), tachygastria (4-10 cpm), dominant frequency instability coefficient (DFIC), and postprandial to fasting power ratio. Data were correlated to results obtained in 18 age- and gender-matched controls. In 10 patients, a control measurement was performed after antithyroid therapy. In addition, in 15 consecutive patients, EGG data were compared to gastric emptying of radionuclides recorded simultaneously (gamma camera). RESULTS: Hyperthyroid patients revealed a significant increase in preprandial DF, and in pre- and post-prandial tachygastrias compared to controls (3.3 cpm vs 3.1 cpm; 8.8% vs 3.5%; 12.3% vs 3.5%; p < 0.05). After antithyroid therapy, postprandial tachygastrias were reduced significantly. About 50% of the patients exhibited delayed gastric emptying compared to previously evaluated normal values (t 60 nuclide retention: > 68%). However, these patients did not differ in tachygastria and the other EGG parameters from those with normal gastric emptying (p > 0.05). Both EGG and radioscintigraphy did not correlate significantly with dyspepsia. CONCLUSIONS: Dyspeptic patients with hyperthyroidism frequently display tachygastria and delayed gastric emptying. However, tachygastria has no important effect on gastric motor activity in hyperthyroidism.     

Postprandial electrogastrographic changes with or without parasympathetic nerve blockade

To investigate the relationship between postprandial electrogastrographic changes and parasympathetic nervous activity, 10 healthy adult males (20 to 29 years old) volunteered for EGG recording in the following conditions: 1) butylscopolamine bromide (scopolamine) administration to block parasympathetic nervous activity; 2) after food intake; and 3) during a postprandial period after the parasympathetic blockade. Power spectral analysis of EGG was performed according to Akaike's autoregressive model. When the parasympathetic nervous activity was blocked, there were no changes in the dominant frequency of the EGG. During the postprandial period, the dominant frequency in EGG increased significantly, and postprandial dip (transient frequency decrease after the food intake) was observed in 8 of the 10 subjects. During the postprandial period after scopolamine administration, the dominant frequency of EGG did not increase, and postprandial dip was observed in only two subjects. These results suggest that the parasympathetic nervous activity is involved in occurrence of postprandial gastric motor function and postprandial electrogastrographic changes.     

Postprandial tachygastria is frequent in infants with gastroesophageal reflux

Cutaneous electrogastrography (EGG) enables non-invasive recording of gastric electrical activity (GEA). Controversial EGG and ultrasonographic (US) results have been described in infants suffering from gastroesophageal reflux (GER). It was the aim of this study to investigate GEA using transcutaneous EGG in a group of infants free of symptoms indicative of GER and a group with GER (mean age 10 months, (range 3-36 months)) and to investigate gastric emptying in both groups using US. We also investigated possible correlations between EGG and US parameters of the gastric emptying curve. The EGG was recorded over a period of at least 120 min (60 min preprandial to 60 min postprandial). US measurements were made just after completion of the meal and then every 30 min up to 180 min. In infants with GER significantly more tachygastria occurred in the postprandial period when compared to healthy infants, in whom normogastria was predominantly observed (P < 0.05). The sonographically-measured gastric emptying curve could be defined in all infants using an exponential function. No significant differences between the groups were noted; there was no significant correlation between EGG parameters and the De Meester score or parameters of the sonographically-measured gastric emptying curve. From the results of this study, transcutaneous EGG recorded within the postprandial period can be of potential clinical value for non-invasive GER screening in infants. However, the EGG cannot be utilized to investigate gastric emptying in infants.     

The effects of acupuncture, electroneedling and transcutaneous electrical stimulation therapies on peripheral haemodynamic functioning

For decades, acupuncture and electroneedling treatments have been used, predominately in the Eastern countries, in the management of patients with compromised cardiovascular and digestive functions. Similarly, neuromuscular electrical stimulation is commonly employed in Western countries to modulate pain, augment muscle strength and enhance blood flow in patients with peripheral vascular disease. Many rehabilitation specialists believe that electrical stimulation of acupuncture points with surface electrodes can elicit the same physiological and therapeutic effects as those produced by acupuncture and electroneedling techniques. Electrical stimulation of acupuncture points with surface electrodes is a relatively new and non-invasive treatment with potential clinical application in the management of patients with peripheral vascular disease. Presently, there are controversies in the literature as to the effects of traditional acupuncture, electroneedling and neuromuscular electrical stimulation treatments on peripheral haemodynamic functioning. This paper provides a detailed review of published studies on the above promising therapies. An attempt was made to clarify the pitfalls in the extant literature and delineate the fact from the fiction. Areas for further research were proposed.     

Measurement of walking endurance and walking velocity with questionnaire: validation of the walking impairment questionnaire in men and women with peripheral arterial disease

This paper presents an application of the continuous wavelet transform (CWT) in the analysis of electrogastrographic (EGG) signals. Due to the nonstationary nature of EGG signals, the CWT method, which uses multiresolution scaled windows, gives a better time-frequency resolution than the short-time Fourier transform, which uses a fixed window. Spike activity due to gastric contraction was investigated through experiments on dogs. During spike activity we observed an increase in magnitude of the slow wave and the appearance of a low frequency component with half the frequency of the slow wave. Studies of the EGG signals from the small intestine are also presented to investigate the hypothesis that its slow wave might be confounded with spike activity in the stomach due to the similarity of their frequency ranges.     

Gastric pacing improves emptying and symptoms in patients with gastroparesis

BACKGROUND & AIMS: No effective treatment is available for patients with gastroparesis refractory to standard medical therapy. The aim of this study was to investigate the effects of gastric pacing on gastric electrical activity, gastric emptying, and symptoms in patients with gastroparesis. METHODS: Nine patients with gastroparesis participated in this study. Four pairs of cardiac pacing wires were implanted on the serosa of the stomach. The protocol consisted of two portions: a temporary inpatient study period and an outpatient study for a period of 1 month or more. RESULTS: Gastric pacing entrained the gastric slow wave in all subjects and converted tachygastria in 2 patients into regular 3-cpm slow waves. Gastric emptying was significantly improved after the outpatient treatment with gastric pacing. The gastric retention at 2 hours was reduced from 77.0% +/- 3.3% to 56.6% +/- 8.6% (P < 0.05). Symptoms of gastroparesis were substantially reduced at the end of the outpatient treatment (1.51 +/- 0.46 vs. 2.84 +/- 0.61; P < 0.04). Eight of 9 patients no longer relied on jejunostomy tube feeding, and no adverse events were noted related to the pacing unit. CONCLUSIONS: Gastric pacing seems to be able to improve symptoms of gastroparesis and to accelerate gastric emptying in patients with gastroparesis. More controlled studies are necessary to further investigate the role of gastric pacing in clinical practice.     

Concept for a behavior therapy treatment program in primary insomnia

Cutaneous recordings of gastric electrical activity (electrogastrography (EGG)) could become a valuable non-invasive tool for recognising gastric electrical abnormalities. Although signals obtained with internally implanted electrodes deliver quantitative information, this technique cannot be used for diagnostic purposes because of its invasive nature. On the other hand, the objectivity of electrogastrography is still in question. The aims of this work are to develop computer techniques for extracting quantitative information from digital electrogastrograms, and to evaluate quantitatively EGG recordings from healthy volunteers. The dynamics of all four EGG parameters are studied: amplitude, frequency, time shift between different channels, and waveform. Four separate two-dimensional computer plots are developed using specially designed digital signal-processing procedures. Each parameter is evaluated in a study of 20 healthy volunteers. Frequency is found to be the only EGG parameter that shows quantitative consistency and merit.     

Effect of capsaicin-containing red pepper sauce suspension on upper gastrointestinal motility in healthy volunteers

Afferent nerves play a major role in the regulation of gastrointestinal motility. The questions remains if specific food ingredients can selectively activate such fibers. The aim of the study was to investigate the effect of intraesophageal application of a capsaicin-containing red pepper sauce (Tabasco) suspension on upper gastrointestinal motility in a controlled trial. After a baseline recording [esophageal motility, balloon distension, electrogastrogram (EGG)], red pepper or saline solution was infused intraesophageally in seven healthy volunteers. At 30 min gastric emptying and orocecal transit time were determined using a [13C]acetate and H2-lactulose breath test. Infusion of red pepper sauce suspension significantly increased the amplitudes (65.8 +/- 3 to 78.5 +/- 4.7 mm Hg, P < 0.05) and propagation velocity (2.9 +/- 0.3 to 4.25 +/- 0.3 sec, P < 0.05) of esophageal pressure waves and LES pressure (17.8 +/- 1.4 to 23.7 +/- 2.6 mm Hg, P < 0.05). It significantly decreased perception and discomfort threshold of intraesophageal balloon distension, reduced the percentage of normal electrical activity in the EGG, and delayed gastric emptying (saline: T(1/2) 42.9 +/- 12.0 min vs red pepper: T(1/2) 66.8 +/- 19.0 min, P < 0.05). Despite the prolongation of gastric emptying, orocecal transit time was not altered, indicating an actual increase of intestinal transit. Esophageal application of capsaicin-containing red pepper sauce suspension had profound changes on upper gastrointestinal motility, which could improve clearance and protection of the esophagus and could lead to retention of the irritant in the stomach and faster transit through the small bowel.     

Detection and deletion of motion artifacts in electrogastrogram using feature analysis and neural networks

Electrogastrogram is a surface measurement of gastric myoelectrical activity, and electrogastrography has been an attractive method for physiological and pathophysiological studies of the stomach due to its noninvasive nature. Motion artifacts, however, ruin the electrogastrogram (EGG), and make the analysis very difficult and sometimes even impossible. They must be eliminated from EGG signals before analysis. Up to now, this can only be done by visual inspection, which is not only time-consuming but also subjective. In this study, a method using feature analysis and neural networks has been developed to realize automatic detection and elimination of the motion artifacts in EGG recordings by computer. Experiments were conducted to investigate the characteristics of different motion artifacts. Useful features were extracted, and different combinations of the features used as the input of the neural network were compared to obtain the optimal performance for the detection of motion artifacts using the artificial neural network.