Covariance Analysis of Bioimpedance Signals for Information Support of Ultrafiltration Procedure

In the paper, the rationale and development of a noninvasive information technology for covariance analysis and control of transient regimes in the patient's biophysical state during the ultrafiltration procedure is given. The analysis of the standard procedure of ultrafiltration during programmed hemodialysis was carried out. Based on the biophysical model of the hydration level of the patient, the specific phases of the ultrafiltration procedure are determined. A comparative analysis of hematocrit level at different phases of the procedure and signals of bioimpedancometry was carried out. To analyze the bioimpedancometry signals at different frequencies, a covariance analysis was used. The use of F-statistics as an information parameter allows non-invasive control of the phase change of the ultrafiltration procedure and the patient's transition to the precritical state. The approach proposed in the work allows us to distinguish the trends of the random bioimpedancometry signal and to monitor the course of the ultrafiltration procedure using the specified decision-making risks.