Method of and a system for determining a cardiovascular quantity of a mammal

摘要

The present invention relates to a method and a system for carrying out the method of determining at least one cardiovascular quantity of a mammal. The method comprises (i) selecting a measuring site of a vessel; (ii) determining or estimating a mean diameter of the vessel at the measuring site; (iii) determining a pulse wave velocity and/or another elasticity related quantity of the vessel at the measuring site; (iv) determining a distension of the vessel at the measuring site; and (v) calculating the at least one cardiovascular quantity from the determined mean diameter, elasticity related quantity and distension of the vessel at the measuring site. The cardiovascular quantity system comprises (i) a plurality of sets of electrodes where each set of electrodes comprising at least two electrodes can be attached to a skin surface of the mammal such that capacitive coupling through the skin surface and between the electrodes of the set of electrodes is provided when an electrical signal is applied over the electrodes at a measuring site of a vessel; (ii) electrical devices for applying an electric oscillating signal over the respective sets of electrodes; (iii) at least one processor and memory unit arranged to receive signals from the respective sets of electrodes; wherein said at least one processor is designed and programmed to calculate the at least one cardiovascular quantity according to the method using signals from the respective sets of electrodes. By calculating the cardiovascular quantity from such data a more accurate determination can be obtained, which determination further is exempt from the need for any individual calibration or any further type of calibration procedure at all, neither before or after measurements. An accurate determination in this context means a determination with a very low measurement uncertainty, such as in the order of about 10% or less, preferably about 5% or less.

主权项

1. A method of determining at least one cardiovascular quantity of a mammal,
comprising: determining or estimating a mean diameter of a vessel at a measuring site by:
applying a plurality of electrical oscillating signals selected from an oscillating current and an oscillating voltage to at least one set of electrodes, wherein the plurality of electrical oscillating signals comprises at least two different excitation frequencies and wherein electric field lines between the at least one set of electrodes penetrate the vessel at the measuring site; anddetermining an impedance between the at least one set of electrodes for each excitation frequency; determining an elasticity related quantity of the vessel at the measuring site; determining a distension of the vessel at the measuring site; and calculating the at least one cardiovascular quantity from the determined mean diameter, the elasticity related quantity and the distension of the vessel at the measuring site.