Scholars@Duke publication: Physical properties of artificial stones made of natural materials (BON(N)-STONES) in comparison to natural and other artificial stones

Physical properties of artificial stones made of natural materials (BON(N)-STONES) in comparison to natural and other artificial stones

Publication , Journal Article

Heimbach, D; Jacobs, J; Hesse, A; Muller, SC; Zhong, P; Preminger, GM

Published in: Journal fur Urologie und Urogynakologie

March 23, 2000

From a clinical point of view the artificial stone phantoms known so far are a compromise for in vitro investigations. Concerning experiments on chemolysis they are not useable because they are not comparable to natural renal calculi. Therefore it was the aim of this study to compare the physical properties of standardized artificial stones made of natural materials (BON(N)-STONES) with natural stones of the same composition. These artificial stones are composed of apatite, magnesium ammonium phosphate hydrogen, brushite, cystine, uric acid and calcium oxalate. The density of the stones was measured by a pycnometer according to Archimedes' principle. The microhardness was tested using a Vicker's indentor. Longitudinal and transversal wave speeds were investigated using an ultrasound puls transmission technique. Wave impedances and dynamic moduli were calculated. The new stone phantom (BON(N)-STONES) is ball-shaped and uniform concerning diameter, volume and weight. Density and microhardness as well as acoustic properties and dynamic mechanic moduli are in good accordance to natural stones of the same composition especially regarding apatite, struvite, uric acid and brushite stones. The results show that BON(N)-STONES are comparable to their natural counterparts concerning physical properties with exception of cystine and calcium oxalate. They are suitable to perform standardized and reproducible investigations in vitro and give substance-specific results. They may be used for quality controls and for scientific experiments.