Patent ID: 7147613

Claim:
A renal replacement therapy system, comprising: a blood treatment device; an extracorporeal fluid circuit including a first panel comprising first and second sheets of flexible material forming a portion of a fluid pathway defined by a pattern of seals; an in-line sensor region between the two flexible sheets, said sensor region being characterized by an expanded portion of said fluid pathway which has substantially flattened walls defined by said flexible sheets; said at least one fluid pathway carrying conveying fresh fluid for consumption by a blood treatment component and waste fluid from said blood treatment component; the at least one fluid pathway, including said expanded portion, being free of an air interface; the blood treatment device including a sensor physically contacting a non-wetted surface of said expanded portion to measure fluid pressure within said first when said fluid; said extracorporeal fluid circuit including a blood circuit portion adapted to circulate blood from an individual through the blood treatment component to treat it and to return treated blood to the individual.