Device and method for determining coronary blood flow
First Claim
1. Device for determining at least the blood flow through at least a selected half of a coronary artery system of a beating heart of a mammal, in particular a human being, during a beat of said heart, comprising a bioimpedance measuring device for measuring an impedance signal Z that depends on said blood flow through at least said selected half of said coronary artery system, which bioimpedance measuring device comprises a current source, supply electrodes, one or more upper measuring electrodes, one or more lower measuring electrodes and measuring means, and further comprising processing means which are connected to said measuring means, for processing of at least a value of said impedance signal Z, and for determining a first time-derivative dZ/dt of said impedance signal Z, wherein said processing means further comprise means for separating from said first time-derivative dZ/dt a peak signal PS corresponding to said selected half of said coronary artery system, which peak signal PS lies within a time interval between the beginning of diastole of said heartbeat and the end of a second peak signal PS2 of said first time-derivative dZ/dt which occurs second after said beginning of diastole, and wherein said processing means are designed to determine said blood flow from said peak signal PS.
1 Assignment
0 Petitions
Accused Products
Abstract
The present invention relates to a device and method for measuring a blood flow through a coronary system of a heart. It was realized that said blood flow causes a temporary change in the impedance of the coronary system, in the form of a peak in a first time-derivative of the impedance signal. The method comprises measuring an impedance signal across the body region containing the coronary system as a function of time, determining a first derivative of the impedance signal with respect to time, and calculating the blood flow from a peak height of a certain peak signal in said derivative impedance signal. The device comprises a bioimpedance measuring device adapted for the method.
29 Citations
17 Claims
-
1. Device for determining at least the blood flow through at least a selected half of a coronary artery system of a beating heart of a mammal, in particular a human being, during a beat of said heart, comprising a bioimpedance measuring device for measuring an impedance signal Z that depends on said blood flow through at least said selected half of said coronary artery system, which bioimpedance measuring device comprises a current source, supply electrodes, one or more upper measuring electrodes, one or more lower measuring electrodes and measuring means, and further comprising processing means which are connected to said measuring means, for processing of at least a value of said impedance signal Z, and for determining a first time-derivative dZ/dt of said impedance signal Z, wherein said processing means further comprise means for separating from said first time-derivative dZ/dt a peak signal PS corresponding to said selected half of said coronary artery system, which peak signal PS lies within a time interval between the beginning of diastole of said heartbeat and the end of a second peak signal PS2 of said first time-derivative dZ/dt which occurs second after said beginning of diastole,
and wherein said processing means are designed to determine said blood flow from said peak signal PS.
-
9. Method for determining at least the blood flow through at least a selected half of a coronary artery system of a beating heart of a mammal, in particular a human being, during a beat of said heart, comprising the steps of
applying upper and lower measuring electrodes to the body of said mammal, wherein said selected half of said coronary artery system is completely between said upper and lower measuring electrodes, measuring an impedance signal Z which depends on the blood flow through said selected half of said coronary artery system, by means of a bioimpedance measuring device which is connected to said upper and lower measuring electrodes, determining a first time-derivative dZ/dt of said impedance signal Z, separating from said first time-derivative dZ/dt a peak signal PS which corresponds to said selected half of said coronary artery system, which peak signal PS lies within a time interval between the beginning of diastole of said heart during said heartbeat and the end of a second peak signal PS2 of said first time-derivative dZ/dt which occurs second after said beginning of diastole, and determining said blood flow from said separated peak signal PS.
Specification