Appts for determn of peripheral impedance during surgical operation

摘要

An extracorporeal bypass (8) is provided from a proximal cannula (7) to a distal cannula (9) which is doubled (10) with proximal and distal limbs to avoid falsification of measurements by formation of collaterals. An e.g. electromagnetic flowmeter (5) and a pressure transducer connection (6) in the bypass are linked to measuring devices (3,4) whose readings are digitised (2) and processed by computer (1). The software determines the peripheral impedance from the quotients of the arterial-to-venous pressure drop and the bypass flow. Pref. the temporal variability of the result is displayed visually and the measurements are stored.