ISSN:
1741-0444
Keywords:
Bimodal local-density random-walk distribution
;
Curve fitting, Indicator dilution technique
;
Quantitative determination of shunts
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract A technique for automatic computation of circulatory shunts from indicator-difution curves is presented. In the case of shunts, dilution curves over the heart and pulmonary circulation comprise two primary curves occasionally with a marked, mutual overlap Quantitative determination of a right to left or left to-right shunt is based on a mathematical spearation of the shunt-dilution curve into the component primary curves. A mathematical model of the bimodal distribution of indicator transit times has been fitted directly to a complete shunt-dilution curve. This model is based on a local-density random-walk approach. Validation of the model is performed by simulations of shunt-dilution curves both mathematically and with a hydrodynamic circulation model. Analysis of the curves. Shows that the technique presented provides reliable and accurate estimates of the amount of shunt even in cases of marked overlap of the primary curves, in which the techniques usually applied are inaccurate or inadequate. This conclusion is confirmed in animal experiments in which we have estimated right-to-left shunts through the torament ovale of newborn pigs
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02442101
Permalink
