ISSN:
1573-2568
Keywords:
GASTRIC ELECTRICAL ACTIVITY
;
ELECTROGASTROGRAPHY
;
RANDOMNESS
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract This study was undertaken to investigate thedynamics of the level of randomness in gastricelectrical signals. Combined recordings of internalgastric electrical activity (GEA) and electrogastrograms(EGG) were obtained from 16 unconscious dogs and twopostoperative patients. The signals were amplified usingspecially designed amplifiers with flexible frequencyrange and were digitized with 10-Hz sampling frequency. The 4.27-min portions of the digitalsignals were subjected to a previously described turningpoint test for randomness. The distributions of thenumber of turning points (NTP) in successive time intervals calculated from all GEA signalswere compared to the estimated NTP distribution of arandom signal. NTP dynamics of internal GEA signals wasalso correlated to the NTP dynamics of cutaneous EGG. In five of 16 recordings from the dogs andin two of the 14 recordings from the patients, NTPvalues calculated from some internal GEA channelsexceeded the 1% probability level for entering thenormal NTP distribution of a random signal (P 〉0.01). In all measurements the distributions of the NTPvalues recorded from cutaneous EGG channels weresignificantly different (P 〈 0.01) from the NTPdistribution of a random signal. There was significantcorrelation (P 〈 0.01) between the NTP dynamics ofinternal GEA and EGG. The level of randomness ininternal GEA recorded with the short-distance bipolartechnique is substantially higher than that in cutaneousEGG, probably due to the occurrence of spike activity.Although the level of randomness in EGG is affected bymany external factors, its dynamics correlated significantly with the level of randomness ininternal GEA.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1018858113172
