Dialysis Bloodline Set and Method of Use

A bloodline set for conveying blood to and from a patient via a dialyzer, the bloodline set including:

• at least one assembly of tubing defining a flowpath for the blood;
• a patient inflow end for receiving a flow of blood from the patient;
• a patient outflow end for returning the flow of blood to the patient;
• dialyzer inlet and outlet connections for connecting the tubing respectively to an inlet and an outlet of a dialyzer so that the flowpath passes through the dialyzer;
• an arterial chamber arranged between the patient inflow end and the dialyzer inlet connection;
• a venous chamber arranged between the dialyzer outlet connection and the patient outflow end;
• and
• a first pressure sensing line;
• the arterial chamber comprising in a use position a lower portion, an upper portion, and a central portion arranged between the lower portion and the upper portion;
• the first pressure sensing line being fluidly connected to the upper portion of the arterial chamber;
• the lower portion including a shoulder, an arterial chamber inflow connection and an arterial chamber outflow connection so that the flowpath extends through the lower portion between the inflow and outflow connections;
• each portion of the arterial chamber having a maximum internal section area defined in a horizontal plane in the use position;
• wherein the maximum internal section area of the lower portion is greater than that of the central portion;
• and the central portion opens into the lower portion at an aperture, and the shoulder is arranged to deflect blood flowing in use through the lower portion from the inflow connection to the outflow connection below a plug of priming liquid in a lower part of the central portion to flow across the aperture to form a dynamic interface between the blood and the priming liquid.