Synthesis of gastrointestinal contractile activity from myoelectric activity
The circular muscle contractions of the gastrointestinal tract produce its mixing and propulsive movements. The amplitude, duration and propagation distance of these contractions are correlated with transit. In animals, these contractions are recorded usually with surgically implanted strain gauge transducers. These transducers are sutured to the seromuscular layer. This technique cannot be used in humans. However, in several studies bipolar electrodes have been implanted intraoperatively to record myoelectric activity. The electrical control activity (ECA or slow waves), thus recorded, controls the maximum frequency and timing of contractions, whereas the electrical response activity (ERA or spike burst) is correlated with contractions. Our objectives were to develop a procedure to analyze the contractile activity as well as the myoelectric activity recorded from canine ileum, to investigate the correlation between the parameters of ERA and of corresponding contractions, and to synthesize the contractile activity from the myoelectric activity. Results. A pattern recognition method was developed to analyze the contractile activity and determine the starting time, amplitude, duration and area under contractions. A procedure to analyze the myoelectric activity was also developed. The frequency of ECA and the start of ECA depolarization's were determined. The parameters of ERA: time lag between the start of ECA and ERA, duration of ERA, number of spikes and power in each burst, were identified. Multiple linear regression was used to determine the correlation coefficients between the parameters of contractions, ECA and ERA. The amplitude of contractions was correlated significantly with the number, amplitude and power of spikes. The duration of contractions was correlated significantly with the number and duration of spikes. The area under contractions was correlated significantly with the amplitude, power, number and duration of spikes. All three parameters of contractions were correlated inversely with the time lag between the start of ECA and ERA. Using these correlations, contractions synthesized from ERA closely resembled the contractions recorded by strain gauge transducers. Conclusions. The canine gastrointestinal contractile activity can be synthesized from the myoelectric activity. The synthesis of contractions may be an important tool to synthesize human gastrointestinal contractions from myoelectric activity recorded by electrodes.
Radwan Maher Baytiyeh,
"Synthesis of gastrointestinal contractile activity from myoelectric activity"
(January 1, 1997).
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