The model parameters are: aortic input impedance (Zo), TPR, and arterial compliance (Cw). They were obtained from studies of human aorta preparation. Individual adjustment is performed based on the subject’s age and gender. As Cw is also affected by diseases, this may lead to inaccuracies.
In the present study, we indicate a way to include in the Windkessel model information obtained by adding carotid pulse recording to the finger pressure measurement. This information allows individualization of the values of Cw and Zo. It also seems reasonable to utilize carotid pulse, which better reflects aortic pressure, to individualize the transfer function.
Despite its simplicity, the Windkessel model describes essential phenomena in the arterial system remarkably well; therefore, it seems worthwhile to check whether individualization of its parameters would increase the reliability of results obtained with this model.
Respiration is the main reason of the chest movements. However, there are also non-respiratory ones, resulting from e.g. snoring, wheezing, stridor, throat clearing or coughing. They may exist sporadically, however should be examined in case when their incidences increase. Detecting non-respiratory movements is very important, because many of them are symptoms of respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD) or lung cancer. Assessment of the presence of non-respiratory movements could be important element of effective diagnosis. It is also necessary to provide quantitative and objective results for intra-subject studies. Most of these events generate vibroacoustic signals that contain components of sound and vibrations. This work provides the review of the solutions and devices for monitoring of the non-respiratory movements, primarily considering the accuracy of the chest movements' detection and distinguishing.