Authors:
Shaun Davidson
1
;
Chris Pretty
1
;
Shun Kamoi
1
;
Thomas Desaive
2
and
J. Geoffrey Chase
1
Affiliations:
1
University of Canterbury, New Zealand
;
2
University of Liège, Belgium
Keyword(s):
Pressure-Volume Loops, Cardiovascular Signals, Clinical Monitoring, Stroke Work.
Abstract:
This paper develops a minimally invasive means of estimating a patient-specific cardiac pressure-volume
loop beat-to-beat. This method involves estimating the left ventricular pressure and volume waveforms using
clinically available information including heart rate and aortic pressure, supported by a baseline
echocardiography reading. Validation of the method was performed across an experimental data set spanning
5 Piétrain pigs, 46,318 heartbeats and a diverse clinical protocol. The method was able to accurately locate a
pressure-volume loop, identifying the end-diastolic volume, end-systolic volume, mean-diastolic pressure and
mean-systolic pressure of the ventricle with reasonable accuracy. While there were larger percentage errors
associated with stroke work derived from the estimated pressure-volume loops, there was a strong correlation
(average R value of 0.83) between the estimated and measured stroke work values. These results provide
support for the potential of the method t
o track patient condition, in real-time, in a clinical environment. This
method has the potential to yield additional information from readily available waveforms to aid in clinical
decision making.
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