A spectral analysis of the myoelectric activity of the left colon in patients with schistosomiasis mansoni

Abstract

The objective of the present study was to perform a spectral analysis of the electrical activity of the left colon of patients with hepatosplenic schistosomiasis. Thirty patients were studied, divided into 2 groups: group A was composed of 14 patients (9 males and 5 females) with hepatosplenic schistosomiasis and group B was composed of 16 female patients without schistosomiasis mansoni. Three pairs of electrodes were implanted in the left colon at the moment of the surgical treatment. The signals of the electric activity of the colon were captured after postoperative recovery from the ileus and fed into a computer by means of a DATAQ data collection system which identified and captured frequencies between 0.02 and 10 Hz. Data were recorded, stored and analyzed using the WINDAQ 200 software. For electrical analysis, the average voltage of the electrical wave in the three electrodes of all patients, expressed as millivolts (mV), was considered, together with the maximum and minimum values, the root mean square (RMS), the skewness, and the results of the fast Fourier transforms. The average RMS of the schistosomiasis mansoni patients was 284.007 mV. During a long period of contraction, the RMS increased in a statistically significant manner from 127.455 mV during a resting period to 748.959 mV in patients with schistosomiasis mansoni. We conclude that there were no statistically significant differences in RMS values between patients with schistosomiasis mansoni and patients without the disease during the rest period or during a long period of contraction.

Diseño e implementación de un sensor Laplaciano activo flexible. Aplicación al estudio del EENG humano en superficie

“…Algunas de estas componentes corresponden a picos energéticos mayores que los presentes en ancho de banda de la OL. Así también se observó que en ocasiones los picos asociados a las interferencias de baja frecuencia eran picos energéticos muy concentrados, situados en torno a una frecuencia inferior a 8 cpm que podrían atribuirse a fuentes de interferencia bioeléctrica como el EGG o el colonograma [Amaris et al 2002, Chen et al 1993a, Ferraz 2005. En otras ocasiones presentaban una distribución espectral más suavizada en la zona definida como baja frecuencia, que en este caso se debían a variaciones lentas del potencial de contacto del electrodo con la piel [Ferrero Corral et al 1994], que provocaban oscilaciones de la línea basal.…”