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. Its primary product includes the NxStage System One (the System One). NxStage operates in two segments: System One and In-Center. The Company markets the System One to hospitals for treatment of acute kidney failure and fluid overload. In addition to the System One, NxStage sells a line of extracorporeal disposable products for use primarily for in-center dialysis treatments for patients with end-stage renal disease (ESRD). These products, which consist of Medisystems, include hemodialysis blood tubing sets, A.V. fistula needles and apheresis needles. The Company's blood tubing set products include the ReadySet High Performance Blood Tubing set (ReadySet), and the Streamline Airless Blood Tubing set (Streamline).