Identification of the Sources of Artefacts in the Holter-Type Impedance Cardiography Recordings

The evaluation of the rate of artefacts during ambulatory impedance cardiography monitoring is one of the fundamental question regarding the applicability of that method. It is also important to know which type of the patient movements create the noisiest recordings. With the aim to evaluate these uncertainties 14 healthy males (23-28 years) underwent examination (using ReoMonitor) in supine position, in moving during supine position, sitting, reading when sitting, walking and walking on stairs. Each of the part of the protocol lasted 3 minutes. The ratio of artefact free cycles to the total number of cycles was calculated for each evolution. It was averaged for each 60 seconds. For this ratio the parameters of descriptive statistics were calculated for the entire group of subjects. The maximum rate of artefacts free cycles was 1.0 and the minimal ratio was 0.25. The average ratio for all manoeuvres was 0.84±0.13. The data shown that the rate of artefacts is not very high and the system might be used to collect signals in a laboratory and in the field for monitoring changes in cardiovascular parameters.