NxStage Medical, Inc. (NxStage)is a medical device company that develops, manufactures and markets products for the treatment of kidney failure, fluid overload and related blood treatments and procedures. The Company�s primary product is the NxStage System One (System One). It also sells needles and blood tubing sets primarily to dialysis clinics for the treatment of end-stage renal disease (ESRD). The Company operates in two segments: System One and In-Center. It distributes its products in three markets: home, critical care and in-center. In the System One segment it sells and rents the System One, PureFlow SL equipment and disposable products in the home and critical care markets. In the In-Center segment, it sells of blood tubing sets and needles for hemodialysis at dialysis centers and needles for apheresis. The Company�s products include the NxStage System One, Streamline Blood Tubing Sets and AV Fistula and Apheresis Needles.