Virtual instrumentation for clinical assessment of cardiovascular and autonomic function

Information about the activity of the autonomic nervous system can be deriv ed by analysis of keg. physiological signals, including ECG and blood press ure, on a beat-to-beat basis. Due to the large amount of data and mathemati cal processing involved, analysis by hand is prohibitive. The solution deve loped facilitates this procedure by performing the processing on a PC-based instrument incorporating existing medical equipment, a data acquisition bo ard and a computer program to acquire and process the physiological signals . The automated virtual instrument was written using LabVIEW(C) as the main platform. The techniques implemented include impedance cardiography. time- and frequency-domain analysis, invasive and non-invasive baroreflex sensit ivity assessment, and forearm blood flow measurements. The system was desig ned to study patients suffering vasovagal blackouts. where the changes that occur in the heart and circulation during an attack could increase underst anding of the physiological processes that underlie their blackouts.