Real-time measurement of ventricular stroke volume variations by continuous arterial pulse contour analysis
First Claim
1. A method for determining a cardiac parameter equal to or derivable from cardiac stroke volume variation (SVV) comprising:
- inputting a waveform data set corresponding to arterial blood pressure over a computation interval that covers at least two cardiac cycles;
calculating a standard deviation value for the waveform data set over each cardiac cycle; and
calculating an estimate of the SVV as a function of the standard deviation values.
1 Assignment
0 Petitions
Accused Products
Abstract
Ventricular stroke volume variation (SVV) is estimated as a function of the standard deviation of arterial blood pressure value measured over each of at least two cardiac cycles, preferably over each of the cardiac cycles in a computation interval covering a full respiratory cycle. In one embodiment, maximum and minimum standard deviation values are determined over the computation interval. SVV is then estimated proportional to the ratio of the difference between the maximum and minimum standard deviation values and the mean of the standard deviation values. In another embodiment, SVV is then estimated proportional to the ratio of the standard deviation of the standard deviation values and the mean standard deviation over the entire computation interval. A pre-processing arrangement for improving reliability of estimates of more general cardiac or hemodynamic parameters is also disclosed and involves smoothing with an approximating function, and sampling and low-pass filtering at an adjustable rate.
-
Citations
18 Claims
-
1. A method for determining a cardiac parameter equal to or derivable from cardiac stroke volume variation (SVV) comprising:
-
inputting a waveform data set corresponding to arterial blood pressure over a computation interval that covers at least two cardiac cycles; calculating a standard deviation value for the waveform data set over each cardiac cycle; and calculating an estimate of the SVV as a function of the standard deviation values. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A system for determining a cardiac parameter equal to or derivable from cardiac stroke volume variation (SVV) comprising:
-
an arrangement for determining and inputting a waveform data set corresponding to arterial blood pressure over a computation interval that covers at least two cardiac cycles; a processing system including computer-executable code for calculating a standard deviation value for the waveform data set over each cardiac cycle; and for calculating an estimate of the SVV as a function of the standard deviation values. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
-
Specification