Model note · Haemodialysis Machine

NxStage System One cycler

Name: NxStage System One cycler
Brand: NxStage System One

The NxStage System One is a small cycler built for home haemodialysis that also works in acute and chronic care units. The cycler is an electromechanical control unit. All blood and fluid paths are in a sterile single use cartridge that clips into it, usually with the dialyser already attached (Cartridge Express). It runs on low dialysate flows, from bags or the PureFlow preparation system. In the US it is cleared for home nocturnal dialysis and, since 2017, solo home dialysis during waking hours. A 2015 software error could keep the ultrafiltration pump removing fluid after the target was reached.

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The model

Maker, model and type.

Maker: NxStage Medical, Inc.; the 2026 clearance is held by Fresenius Medical Care Renal Therapies Group, LLC
Model: NxStage System One cycler (NX1000 series) with Cartridge Express
Device type: Haemodialysis Machine
Main document: Open the public document

Key specifications

What the public record says.

Item	Value	Source
FDA classification and clearances	High permeability haemodialysis system, 21 CFR 876.5860, Class II, product code KDI; K171331 (24 August 2017, solo home HD), K232803 (14 March 2024, Cartridge Express CAR-170-E and CAR-172-E), K252377 (15 May 2026, with NxView)	Source
Therapies and settings	Haemofiltration, haemodialysis and ultrafiltration in acute or chronic care facilities; haemodialysis with or without ultrafiltration at home, including nocturnal and solo during waking hours	Source
System parts	NxStage Cycler (control unit) plus a sterile, single use cartridge that holds the whole blood and fluid circuit and mounts inside the cycler	Source
Cartridge Express clearance in vitro (no UF)	At dialysate 100 mL/min and blood 200 to 400 mL/min: urea 100, creatinine 97 to 100, vitamin B12 84 to 95 mL/min. At dialysate 200 mL/min and blood 400 to 500 mL/min: urea 195 to 199, creatinine 182 to 186, B12 138 to 143 mL/min	Source
Cartridge Express variants	CAR-170-E standard and CAR-172-E with needleless access sites; gamma sterilised; PETG housed high permeability fibre dialyser	Source
Cycler models named in recalls	NX1000-1, NX1000-3 and NX1000-4	Source

Recalls

Known FDA recalls.

Z-2793-20182018-06-11
Express Fluid Warmer: electrical fire risk if fluid leaks into the power receptacle; 7 reports of smoke, sparks or flames (14,975 units).
FDA record
Z-1132-20182017-11-10
PureFlow B labelling did not warn against mixing formulations or say to check fluid is flowing (1,243,400 units).
FDA record
Z-0335-20162015-10-29
Software error: ultrafiltration volume may not decrease and the UF pump may keep removing fluid after the target (NX1000-3, NX1000-4).
FDA record
Z-0826-20122011-12-14
PureFlow SL SAK with excess concentrate causing high conductivity alarms.
FDA record

Safety

Safety warnings from the record.

The ultrafiltration pump could keep removing fluid after the target volume was reached (2015, 2,134 cyclers); nocturnal patients were told to get a replacement NX1000-1 cycler until the fix. Source
Hanging more than one dialysate formulation at once is not an intended use and can harm the patient. Source
Solo home dialysis carries a higher risk from needle dislodgement; FDA cleared it with labelling informed by a patient preference study of 142 home patients. Source

Sources

Where this note comes from.

Not covered: The NxStage operator and service manuals were not read, so blood flow and ultrafiltration setting ranges, alarm codes, weight and maintenance intervals are not included. The second design note is a BMEssentia reading of the clearance table.

BMEssentia knowledge drafted from public information, reviewed by Hasan Khaled Ismail on 2026-10-24. Always follow the manufacturer's instructions for use and service manual.

Haemodialysis Machine