Patent ID: 8603021

Claim:
An ultrafiltration filter for an extracorporeal blood circuit having an input for blood withdrawn from a human patient and a blood output for filtered blood to be infused into the patient, said ultrafiltration filter comprising: a filter body having a length of at least 20 centimeters (cm) and an interior diameter of no greater than 1.5 cm; an input at a first end of the body to receive the withdrawn blood; an output at a second end of the body to discharge the filtered blood; a filter membrane in the body defining a blood passage through the body, wherein the membrane has an active filter membrane surface area of no greater than 0.2 meters squared (m 2 ) and the filter membrane blocks passage of blood molecules having a molecular weight cut of greater than 60,000 Daltons and a volume of the blood passage in the filter being less than two percent of a cardiac output of the patient, and an ultrafiltrate output to the body and open to a side of the filter surface area opposite to the blood passage.