Device For Determining the Transition Between Systole and Diastole
First Claim
1. Device for determining the transition between systole and diastole within a pulse cycle, having an input channel (1) for reading in a pressure signal that can change over time and at least approximately corresponds to the aorta pressure of a patient, as a function of the time P(t), and a calculation unit that has differentiation means for forming the second derivation y″
- from the function P(t), as well as evaluation means for determining a location of maximal curvature of the function P(t) in a determination range between the maximal and the minimal function value of the pulse cycle as the location of the transition between systole and diastole.
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Accused Products
Abstract
Determining the transition between systole and diastole is important for pulse contour-analytical determination of hemodynamic, first of all cardiac output. During the temporal progression of arterial pressure P(t) on which pulse contour analysis is based, the transition between systole and diastole appears as a local minimum. This local slump of the pressure curve downward is very short and is often little recognizable in the actually measured curves due to inaccuracies conditioned by measuring techniques. It was also found that the transition between systole and diastole can be more reliably and accurately determined as the site of maximum curvature of function P(t). Consequently, the invention relates to a device having a calculation unit that comprises evaluation means for detecting the site of maximum curvature of function P(t) in a detection area between the maximum and minimum functional value of the pulse cycle as the site of transition between systole and diastole.
4 Citations
13 Claims
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1. Device for determining the transition between systole and diastole within a pulse cycle, having an input channel (1) for reading in a pressure signal that can change over time and at least approximately corresponds to the aorta pressure of a patient, as a function of the time P(t), and a calculation unit that has differentiation means for forming the second derivation y″
- from the function P(t), as well as evaluation means for determining a location of maximal curvature of the function P(t) in a determination range between the maximal and the minimal function value of the pulse cycle as the location of the transition between systole and diastole.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
Specification