US 8,801,618 B2 · Pulse contour method and apparatus for continuous assessment of a cardiovascular parameter

Abstract

A cardiovascular parameter such as cardiac output is estimated from a current pressure waveform data set without needing to directly measure blood flow or arterial compliance. The general shape of an input flow waveform over one beat-to-beat cycle is assumed (or computed), and then the parameters of a flow-to-pressure model, if not pre-determined, are determined using system identification techniques. In one embodiment, the parameters thus determined are used to estimate a current peripheral resistance, which is used not only to compute an estimate of the cardiovascular parameter, but also to adjust the shape of the input flow waveform assumed during at least one subsequent beat-to-beat cycle. Another embodiment does not require computation of the peripheral resistance and still another embodiment computes a flow estimate from an optimized identification of the parameters defining the assumed input flow waveform.

Claims19

Dependent claims

A method for determining, using a current pressure waveform corresponding to arterial blood pressure over a current pressure cycle, a cardiovascular parameter equal to or derivable from cardiac output (CO) comprising:

determining, by a processing system, defining parameters of an assumed input flow waveform as a function of shape characteristics of the current pressure waveform and of a peripheral resistance value determined for at least one previous pressure cycle;
determining, by the processing system, model parameters of a model of a relationship between the assumed input flow waveform and the current pressure waveform;
computing a current peripheral resistance value as a function of the model parameters;
and
computing an estimate of the cardiovascular parameter as a function of the current peripheral resistance value and the current pressure waveform.

2 more elements

A system for determining, using a current pressure waveform corresponding to arterial blood pressure over a current pressure cycle, a cardiovascular value equal to or derivable from cardiac output (CO) comprising:

a processing system including:
an input flow waveform generation module comprising computer-executable code for determining defining parameters of an assumed input flow waveform as a function of shape characteristics of the current pressure waveform and of a peripheral resistance value determined for at least one previous pressure cycle;
a system a parameter identification module comprising computer-executable code for determining model parameters of a model of a relationship between the assumed input flow waveform and the current pressure waveform;
a model parameter computation module comprising computer-executable code for computing a current peripheral resistance value as a function of the model parameters;
and
a cardiovascular value computation module comprising computer-executable code for computing an estimate of the cardiovascular parameter as a function of the current peripheral resistance value and the current pressure waveform.

3 more elements

Dependencies are inferred from the claim text.

Pulse contour method and apparatus for continuous assessment of a cardiovascular parameter

Life of this patent

Pulse contour method and apparatus for continuous assessment of a cardiovascular parameter

Life of this patent

Abstract

Claims19