Reverse engineering the kidney: modelling calcium oxalate monohydrate crystallization in the nephron

• Published in: Medical & biological engineering & computing Vol. 48; no. 7; pp. 649 - 659
• Main Authors: Borissova, A, Goltz, G. E, Kavanagh, J. P, Wilkins, T. A
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01.07.2010; Springer-Verlag; Springer Nature B.V
• Subjects: Algorithms; Bioengineering; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedicine; Calcium; calcium oxalate; Calcium Oxalate - urine; Chemical engineering; Chemical Engineering - methods; Computer Applications; Crystallization; Crystals; Human Physiology; Humans; Hydrodynamics; Imaging; Input output; Kidney Calculi - metabolism; Kidney diseases; Kidney stones; Kidney Tubules, Distal - metabolism; kidneys; Models, Biological; Original Article; Population balance; Radiology; Reverse engineering; Simulation; Studies; Urine; Calcium oxalate; Simulation; Kidney; Population balance; Crystallization
• ISSN: 0140-0118; 1741-0444
• DOI: 10.1007/s11517-010-0617-y

Crystallization of calcium oxalate monohydrate in a section of a single kidney nephron (distal convoluted tubule) is simulated using a model adapted from industrial crystallization. The nephron fluid dynamics is represented as a crystallizer/separator series with changing volume to allow for water removal along the tubule. The model integrates crystallization kinetics and crystal size distribution and allows the prediction of the calcium oxalate concentration profile and the nucleation and growth rates. The critical supersaturation ratio for the nucleation of calcium oxalate crystals has been estimated as 2 and the mean crystal size as 1 μm. The crystal growth order, determined as 2.2, indicates a surface integration mechanism of crystal growth and crystal growth dispersion. The model allows the exploration of the effect of varying the input calcium oxalate concentration and the rate of water extraction, simulating real life stressors for stone formation such as dietary loading and dehydration.