N.A. Bazaev – Ph.D. (Eng.), Senior Research Scientist, I.M. Sechenov First Moscow State Medical University;

Senior Lecturer, Biomedical Systems Institute, National Research University of Electronic Technology (Moscow)

E-mail: bazaev-na@ya.ru

Statement of the problem. Development of wearable artificial kidney (WAK) is one of the most promising directions of research in the field of renal replacement therapy. For almost 40 years, several different science groups were developing various prototypes of such device, but none of them became market-available.

Despite the considerable progress in science and technology, there are only two prototypes of lightweight WAK (less than 5 kg) are on the stage of clinical trials: AWAK (AWAK Technologies, Singapore) and WAK (Blood Purification Technologies, USA), though there are more than ten prototypes in the world [1-4].

WAK has potential to overcome a number of drawbacks of the existing dialysis machines, such as high dialysate usage (>150 L per procedure), large dimensions and mass (> 80 kg), low biocompatibility due to high intensity of procedure. 

Aim of the work – to critically overview of the general problems associated with WAK development. These problems are formulated as the result of more than 8 years of experience in development and preclinical trials of the first Russian prototype of WAK ("Renart-PD"). The developed apparatus is equal or better in its characteristics to foreign analogues (0.8 g/h urea removal rate, 3.5 kg device mass) and is ready to undergo clinical trials. Results: The work highlights key aspects of:

• WAK functioning and basic principles of operation; 
• Dialysate regeneration: uremic toxins to be removed and their mass removal rate, ionic composition stability, dialysate regeneration methods with their cons and pros; 
• WAK composition: controlling and actuating units’ functions, characteristics, problems and their solutions;
• WAK characteristics: weight, dimensions, ergonomics, efficiency;
• WAK usage in economic terms: is it cost-effective and offers enough advantages over conventional renal replacement therapy options. 

Experience of foreign teams (AWAK, Nanodialysis etc.) in this field of research and development are also were taken into consideration, especially from science groups of V. Gura, A. Davenport, M. Wester.

Practical significance. The article reflects the designing process of wearable equipment for blood purification in terms of system analysis and biotechnical system that include elements of different nature, interaction among which require application of different methods for optimization and regulation, which helps during initial designing of such systems.

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