Method for recovering residual blood from an extracorporeal circulation circuit and equipment for collecting and recovering residual blood in the extracorporeal circulation circuit

A residual blood collection and recovery system for an extracorporeal circulation circuit, comprising:

• a hemofilter provided with hollow fibers, an inlet end, and an outlet end;
• a pump connected upstream of the hemofilter;
• an inlet flow sensor connected upstream of the pump;
• an inlet pressure sensor connected to the inlet end of the hemofilter;
• a flow-limiting valve disposed in the outlet end of the hemofilter,
• wherein the flow limiting valve comprises a flexible membrane molded in a sphincter format,
• wherein the flexible membrane is assembled inside a hermetically sealed rigid casing such that the flexible membrane divides an inner pathway of the flow limiting valve and is provided between a compartment filled with compressed air and a blood flow compartment,
• wherein the flow limiting valve is configured to transition from a closed position to an open position when a pressure of the blood flow leaving the hemofilter corresponds to an opening pressure of the flow limiting valve,
• wherein the flow-limiting valve mechanically and automatically regulates a resistance in a line as a function of the flow-limiting valve inlet pressure,
• wherein an automatic regulation includes a mechanical opening and closing of the membrane of the flow-limiting valve and wherein the automatic regulation is proportional to a flow in the line and a hematocrit;
• an actuator in fluid communication with the compartment filled with compressed air of the flow limiting valve;
• an outlet pressure sensor arranged in the hermetically sealed rigid casing of the flow limiting valve;
• an outlet flow sensor connected downstream of the flow limiting valve;
• and
• a computer processing unit (CPU) interconnected with the pump, the inlet flow sensor, the outlet flow sensor, the inlet pressure sensor, the outlet pressure sensor, and the actuator,
• wherein the CPU is configured to:
• drive the actuator for controlling the opening pressure of the flow limiting valve,
• continuously calculate a transmembrane pressure and a filtration efficiency, and
• maintain a transmembrane pressure at a magnitude lower than a maximum transmembrane pressure supported by the hemofilter hollow fibers.