Paper Info
Title
Modelling of electrical impedance epigastrography signals to investigate the efficacy of a motion artifact rejection algorithm
Abstract
Electrical Impedance Epigastrography (EIE) is a non-invasive method that allows the assessment of gastric emptying rates without using ionizing radiation. This method works by applying an alternating current with a frequency of 32 kHz, which can be varied by the operator from 1 to 4 mA, through electrodes over the epigastric region, and measuring the potential difference between them. The post acquisition analysis relies on the Short-Time Fourier Transform (STFT) to extract the gastric motility component of the signal (centre frequency of 0.05 Hz with a bandwidth of 0.02 Hz). Motion artifacts that occur during the test have been found to produce positive and negative spikes. Software was produced to model the EIE signals and apply simulated motion artifacts of known amplitude at specific points in the signal. The signals were labelled pseudo EIE signals. Due to the large frequency range of a delta function, the spikes produced false positives in the frequency domain, suggesting the presence of gastric contractility when there was none, or exaggerating the magnitude of real events in both real and pseudo EIE signals. A motion artifact rejection algorithm (MARA) was developed for removing the artifacts in the time domain, before processing by the STFT. The efficacy of the algorithm was tested on the pseudo EIE signals by comparing the power density calculated by the STFT before and after the simulation of artifacts and after the application of the algorithm.
Year
Venue
Keywords
2005
J. Comput. Meth. in Science and Engineering
eie signal,gastric motility component,frequency domain,pseudo eie signal,gastric emptying rate,gastric contractility,motion artifact rejection algorithm,motion artifact,large frequency range,electrical impedance epigastrography signal,centre frequency,signal processing
Field
DocType
Volume
Time domain,Frequency domain,Signal processing,Algorithm,Short-time Fourier transform,Electrical impedance,Fourier transform,Bandwidth (signal processing),Amplitude,Physics
Journal
5
Issue
ISSN
Citations 
1
1472-7978
0
PageRank 
References 
Authors
0.34
0
3
Name
Order
Citations
PageRank
M. R. Freedman100.34
Anastasios Gaitanis262.51
N. M. Spyrou300.34