In vitro and finite-element model investigation of the conductance technique for measurement of aortic segmental volume. Ann Biomed Eng 1996;24(6):675-84
Date
11/01/1996Pubmed ID
8923987DOI
10.1007/BF02684180Scopus ID
2-s2.0-0030296870 (requires institutional sign-in at Scopus site) 13 CitationsAbstract
This investigation examined the feasibility of applying the conductance catheter technique for measurement of absolute aortic segmental volume. Aortic segment volume was estimated simultaneously in vitro by using the conductance catheter technique and sonomicrometer crystals. Experiments were performed in five isolated canine aortas. Vessel diameter and pressure were altered, as were the conductive properties of the surrounding medium. In addition, a three-dimensional finite-element model of the vessel and apparatus was developed to examine the electric field and parallel conductance volume under different experimental conditions. The results indicated that in the absence of parallel conductance volume, the conductance catheter technique predicted absolute changes in segmental volumes and segmental pressure-volume relationships that agreed closely with those determined by sonomicrometry. The introduction of parallel conductance volume added a significant offset error to measurements of volume made with the conductance catheter that were nonlinearly related to the conductive properties of the surrounding medium. The finite-element model was able to predict measured resistance and parallel conductance volume, which correlated strongly with those measured in vitro. The results imply that absolute segmental volume and distensibility may be determined only if the parallel conductance volume is known. If the offset volume is not known precisely, the conductance catheter technique may still be applied to measure absolute changes in aortic segmental volume and compliance.
Author List
Hettrick DA, Battocletti JH, Ackmann JJ, Linehan JH, Warltier DCMESH terms used to index this publication - Major topics in bold
AnimalsAorta, Thoracic
Calibration
Catheterization, Peripheral
Compliance
Dogs
Electric Conductivity
Electromagnetic Fields
Feasibility Studies
Female
In Vitro Techniques
Male
Models, Cardiovascular
Regression Analysis
Sensitivity and Specificity
