Abstract: The invention relates to a method for obtaining an indication of cardiac output, comprising the steps of introducing into the bloodstream a liquid with a temperature lower than the temperature of the blood, measuring downstream the temperature variation of the blood, and performing a thermodilution algorithm on the basis of the measured temperature variation of the blood. The invention is distinguished in that the temperature variation is measured upstream of the heart in the blood flow of a vein in which the flow rate is substantially proportional to the cardiac output, and the flow rate in the vein is determined using the thermodilution algorithm. The invention also relates to an assembly, catheter and processing device for obtaining an indication of cardiac output.

Abstract: The invention relates to a method and device for determining the flow in a blood vessel, comprising the determining the relation between the shear rate and the impedance of flowing blood, measuring the impedance in the blood in a cross-section of the blood vessel, determining the shear rate from this relation and the measured impedance, determining the size of the cross-section of the blood vessel, selecting a theoretical relative flow distribution over the blood vessel cross-section, determining the average flow speed on the basis of the average shear rate and the relative flow distribution, and determining the flow volume from the determined average flow speed and the cross-section.

Abstract: An assembly of a catheter and a portable data managing device is disclosed. The catheter includes a tubular body with a distal end portion to be introduced into the body of a person and a proximal end portion, including at its distal end portion at least one sensing member and at least one connecting device extending to the proximal end portion for connecting the sensing member to the data managing device. The data managing device includes a control and processing device for controlling the at least one sensing member and processing signals generated thereby.

Abstract: The invention relates to a method for determining properties of blood, such as the blood viscosity of a person, comprising of generating in vivo for a determined time, by means of an electrical alternating current of a determined frequency, a measurement signal of the impedance of the blood between at least two points centrally in a blood volume, wherein the measurement signal is processed such that variations therein with a frequency in the order of magnitude of the heart frequency are substantially absent therefrom, and comparing the processed measurement signal with predetermined relations between impedance and the properties of the blood, such as the viscosity.