In vitro and in vivo trials of wearable artificial kidney

This paper presents results of in vitro and in vivo trials of a wearable artificial kidney (WAK) based on peritoneal dialysis. Materials and methods: in vitro trials were carried out in a developed test bench, which imitates patient's peritoneal cavity and capable to measure main procedure parameters. In vivo trial was carried out on a 15 kg dog in a healthy state to evaluate the effect of WAK on blood biochemical indicators and in an acute kidney injury state to test WAK's blood purification capabilities. Results: in vitro trials demonstrated that WAK could eliminate urea, uric acid and creatinine from spent dialysate with mean mass rates of 0.85±0.1 g/h, 0.10±0.04 g/h and 0.05±0.01 g/h respectively. Concentrations of Na+, Cl^- and Ca²⁺ ions are kept in 10 % range from initial values. It is demonstrated that WAK can operate without replacement of expendable materials for 38 hours. During in vivo trial (39,5 hours), WAK performed continuous peritoneal dialysis with dialysis fluid regeneration. In acute kidney injury conditions (34 hours) creatinine and uric acid were eliminated from dialysing solution with the rate of 0,3 mg/h, urea was eliminated at the rate of 0,15 g/h, total removed ultrafiltrate volume was 350 ml. At the end of the second stage blood biochemical indicators stabilised in the range of normal values. Conclusion: developed WAK can perform elimination of metabolites from spent dialysis fluid with mass rates that are sufficient to maintain stable, physiologically normal metabolite concentrations in patient's blood.