ABSTRACT
The goal of the present study was to develop and evaluate algorithms for non-invasive, real-time, beat-to-beat monitoring of stroke index (SI), blood pressure (BP) and total peripheral resistance index (TPRI) which has a menu-driven interface, suitable for routine use by unskilled staff. In addition, it was our aim to include a meta-analysis for the evaluation of autonomic function derived from the above haemodynamic data. This includes spectral analysis of heart rate (HR), BP, SI and TPRI and the automatic calculation of baroreceptor reflex sensitivity. Impedance cardiography was used for beat-to-beat SI determination, Finapres corrected by an oscillometric blood pressure measurement (Dinamap) on the upper arm for beat-to-beat BP measurement. We demonstrate noise free recordings during physiological (head up tilt) and pharmacological intervention (alpha 1-, beta 2-adrenoreceptor agonists, insulin induced hypoglycemia). The newly developed software should prove valuable for physiological, pharmacological and clinical studies.
Subject(s)
Autonomic Nervous System/physiopathology , Electrocardiography/instrumentation , Hemodynamics/physiology , Monitoring, Physiologic/instrumentation , Signal Processing, Computer-Assisted/instrumentation , Software , Adult , Albuterol , Autonomic Nervous System Diseases/diagnosis , Autonomic Nervous System Diseases/physiopathology , Blood Pressure/physiology , Blood Pressure Monitors , Cardiography, Impedance/instrumentation , Computer Systems , Female , Humans , Insulin , Male , Methoxamine , Middle Aged , Pressoreceptors/physiopathology , Reference Values , Reflex/physiology , Stroke Volume/physiology , Vascular Resistance/physiologyABSTRACT
A variety of monitoring systems is available for special fields of clinical application and scientific research. Whenever requirements change data acquisition and handling of signal analysis have to be adapted or even completely new structured, especially in real-time applications. This can be a time consuming procedure. In order to be able to focus on the development of algorithms without taking care how data are acquired a monitoring system has been developed which can be adjusted in terms of signal acquisition, analysis and user handling. New algorithms can be added and polygraphical presentation of results can be adjusted for special clinical requirements. As a specific application the online and real time calculation left ventricular ejection time (LVEJT), stroke volume (SV), cardiac output (CO), mean blood pressure and total peripheral resistance (TPRI) is presented.
