Inter-pulse intervals of external anal sphincter surface EMG signals recorded from colorectal cancer patients

TL;DR

This study analyzes the electrical pulse intervals of external anal sphincter EMG signals in colorectal cancer patients, revealing consistent statistical properties and correlations across different treatment stages.

Contribution

It provides a detailed statistical characterization of sphincter EMG pulse intervals, highlighting their stable distribution and correlation features during cancer treatment.

Findings

Probability distribution of intervals fits stretched exponential functions

Interval trains show strong correlations unlike shuffled data

No clustering effects observed in the interval data

Abstract

Intervals between electrical pulses generated by the electrical activity produced by the motor units of an external anal sphincter were studied at four time intervals during multimodal rectal cancer treatment. Probability distribution function of such intervals does not exhibit significant differences for all considered time intervals. It is found that the probability distribution rescaled with an average interval time can be described by means of the stretched exponential function with the threshold dependent scale and shape parameters. Interval trains possess rather strong correlations as their shuffled counterparts show exponential Poisson like probability distribution. Finally the clustering effects were not found as the conditional probability distributions can also be described by the exponential function.