NxStage Medical, Inc. is a medical technology company. The Company is engaged in the development, manufacturing and marketing of products and services for patients suffering from chronic or acute kidney failure. The Company operates through three segments: System One, In-Center and Services. It offers its products and services to various markets, such as home, critical care and in-center. The System One segment is engaged in the sale and rental of the System One and PureFlow SL dialysate preparation equipment, and the sale of disposable products in the home and critical care markets. The In-Center segment is engaged in the sale of blood tubing sets and needles for hemodialysis, primarily for the treatment of end-stage renal disease (ESRD) patients at dialysis clinics, and needles for apheresis. The Services segment offers dialysis services provided to patients at its NxStage Kidney Care dialysis centers.