Investigation of the speed of response of a hemodialysis system

Conclusions

1. The response speed of a hemodialysis system depends on the multiplicity of change of the concentration of the low-molecular substance in an equivalent volume of an organism, size of the equivalent volume, velocity of the blood flow, clearance of the dialyzer, and also on the multiplicity of the flow rate of the dialyzate and number of periods of recirculation (in a system with recirculation) and velocity of the dialyzate (in a system with discharge).

2. In a system with recirculation with a multiplicity of the change of concentration of 2, 5, and 10, the multiplicity of the flow rate of the dialyzate should be selected respectively in limits from 2 to 4, from 5 to 10, and from 7 to 15. With an increase of the flow rate above these values the dialysis time decreases little; with a decrease of the flow rate the dialysis time increases considerably. With a multiplicity of the change of concentration of more than 2 the flow rate of the dialyzate should be realized in 2–3 equal volumes with the same period of recirculation of these volumes through the dialyzer.

3. At a constant velocity of the blood flow and equal flow rate of the dialyzate the ratio of the dialysis time in the system with discharge of the dialyzate to the dialysis time in the system with recirculation is equal to the ratio of clearances of the dialyzers with recirculation and discharge.