The NxStage PureFlow SL module is an optional accessory to the NxStage System One that prepares dialysate for use during hemodialysis, as prescribed by the physician.
Device Story
The NxStage PureFlow SL (PFSL) is an accessory to the NxStage System One hemodialysis system. It processes water and proportions it with dialysate concentrate to produce dialysate for hemodialysis. The system comprises a Control Unit, water Pre-Treatment Unit, optional OPTA Kit, Purification Pack (PAK), and Dialysate Sack (SAK). The device is used to prepare dialysate for clinical or home hemodialysis settings. This modification extends the mix-to-use (MTU) time of prepared dialysate from 72 to 96 hours. The healthcare provider uses the produced dialysate for patient treatment; the device ensures the dialysate meets specific purity standards, potentially benefiting patients by extending the duration of dialysate availability.
Clinical Evidence
Bench testing only. Testing included stability, bioburden, and endotoxin analysis on validation batches of dialysate to support the 96-hour MTU duration. Results confirmed compliance with ANSI/AAMI/ISO 11663:2009 requirements, specifically < 100 CFU/ml bioburden and < 0.5 EU/ml endotoxin (LAL).
Technological Characteristics
The system includes a Control Unit, water Pre-Treatment Unit, Purification Pack, and Dialysate Sack. It functions by water treatment and proportioning of dialysate concentrate. It adheres to ANSI/AAMI/ISO 13959:2009, 26722:2009, and 11663:2009 standards. The modification involves firmware/control logic changes to support a 96-hour MTU duration.
Indications for Use
Indicated for patients requiring hemodialysis, as prescribed by a physician, using the NxStage System One.
Regulatory Classification
Identification
A hemodialysis system and accessories is a device that is used as an artificial kidney system for the treatment of patients with renal failure or toxemic conditions and that consists of an extracorporeal blood system, a conventional dialyzer, a dialysate delivery system, and accessories. Blood from a patient flows through the tubing of the extracorporeal blood system and accessories to the blood compartment of the dialyzer, then returns through further tubing of the extracorporeal blood system to the patient. The dialyzer has two compartments that are separated by a semipermeable membrane. While the blood is in the blood compartment, undesirable substances in the blood pass through the semipermeable membrane into the dialysate in the dialysate compartment. The dialysate delivery system controls and monitors the dialysate circulating through the dialysate compartment of the dialyzer.(1) The extracorporeal blood system and accessories consists of tubing, pumps, pressure monitors, air foam or bubble detectors, and alarms to keep blood moving safely from the blood access device and accessories for hemodialysis (§ 876.5540) to the blood compartment of the dialyzer and back to the patient. (2) The conventional dialyzer allows a transfer of water and solutes between the blood and the dialysate through the semipermeable membrane. The semipermeable membrane of the conventional dialyzer has a sufficiently low permeability to water that an ultrafiltration controller is not required to prevent excessive loss of water from the patient's blood. This conventional dialyzer does not include hemodialyzers with the disposable inserts (Kiil type) (§ 876.5830) or dialyzers of high permeability (§ 876.5860). (3) The dialysate delivery system consists of mechanisms that monitor and control the temperature, conductivity, flow rate, and pressure of the dialysate and circulates dialysate through the dialysate compartment of the dialyzer. The dialysate delivery system includes the dialysate concentrate for hemodialysis (liquid or powder) and alarms to indicate abnormal dialysate conditions. This dialysate delivery system does not include the sorbent regenerated dialysate delivery system for hemodialysis (§ 876.5600), the dialysate delivery system of the peritoneal dialysis system and accessories (§ 876.5630), or the controlled dialysate delivery system of the high permeability hemodialysis system § 876.5860). (4) Remote accessories to the hemodialysis system include the unpowered dialysis chair without a scale, the powered dialysis chair without a scale, the dialyzer holder set, dialysis tie gun and ties, and hemodialysis start/stop tray.
{0}------------------------------------------------
K111174
page 1 of 2
SEP 19 2011
This 510(k) Summary is being submitted in accordance with the requirements of the SafeSEP 1 9 2011
Modied Baying Art (OMDA) of 1999 - The section at including this all in Medical Device Act (SMDA) of 1990. The content contained in this 510(k) summary has been provided in conformance with 21 CFR §807.92.
9045797
Mary Lou Stroumbos
(978) 687-4872
(978) 687-4750
Date of Summary: August 26, 2011
A. Submitter's Information:
| Name: | NxStage Medical, Inc. |
|----------|---------------------------------------------------------|
| Address: | 439 South Union Street, 5th Floor<br>Lawrence, MA 01843 |
FDA Establishment Owner/Operator Number:
Contact Person:
Phone: Fax:
Manufacturer:
Entrada Group/NxStage Carretera Fresnillo A Plateros, KM2 Fresnillo, Zacatecas 99059 Mexico
Sr. Regulatory Affairs Associate
FDA Establishment Registration Number:
3006546166
Sterilization Site:
Steris Isomedix, Inc. 1000 S. Sarah Place Ontario, CA 91761
- B. Subject Device Name: Trade/Proprietary Name: Common/Usual Name: Classification Name: Regulation Number: Product Code: Device Classification: Device Panel:
NxStage PureFlow SL Subsystem, proportioning Hemodialysis systems and accessories 21 CFR 876.5820 78 FKR Class II Gastroenterology-Urology (GU)/Gastro-Renal (GRDB)
510(k) Summary NxStage Medical, Inc.
{1}------------------------------------------------
K111174
page 2 of 2
### C. Substantial Equivalence:
This submission is a Special 510(k) Device Modification as described in the FDA's Guidance document entitled, "The New 510(k) Paradigm - Alternate Approaches to Demonstrating Substantial Equivalence in Premarket Notifications." In support of this Special 510(k), NxStage has provided certification of compliance to 21 CFR §820.30 Design Control Requirements. Design validation testing was performed to ensure that the NxStage PureFlow SL (PFSL) module with modification to increase the mix to use (MTU) time of the prepared dialysate from 72-hours to 96-hours meets design specifications. The NxStage PFSL module with modifications has been compared to the legally marketed PFSL predicate device as cleared through K080919 (October 15, 2008) and was found to be substantially equivalent.
# D. Device Description/Indications for Use:
The NxStage PFSL module is an optional accessory to the NxStage System One that is used to treat water for hemodialysis per ANSI/AAMI/ISO 13959:2009 and ANSI/AAMI/ISO 26722:2009 and proportion it with dialysate concentrate to produce dialysate per ANSI/AAMI/ISO 11663:2009. The PFSL module consists of the Control Unit (CU), the water Pre-Treatment Unit, the optional OPTA Kit, the Purification Pack (PAK), and the Dialysate Sack (SAK) with Dialysate Concentrate.
### Indications for use:
The NxStage PureFlow SL module is an optional accessory to the NxStage System One that prepares dialysate for use during hemodialysis, as prescribed by the physician.
### E. Technological Characteristics:
The indications for use of the proposed device and of the predicate device are identical. There is no change to the indications for use or intended use of the PureFlow SL module, and the modification has no affect on the fundamental scientific technology of the device. The proposed device has the same technological characteristics and is similar in design and configuration as compared to the predicate device.
# F. Summary of Non-Clinical Test/Performance Testing - Bench
NxStage believes that the information and data provided in this submission clearly describes the proposed device and demonstrates that the device is adequately designed for the labeled indications for use. Performance and verification and validation testing was conducted to characterize performance of the proposed device. This included stability, bioburden and endotoxin testing on validation batches of dialysate to support the extension of the MTU duration to 96-hours. All predetermined acceptance criteria were met. The NxStage PureFlow SL meets the ANSI/AAMI/ISO 11663:2009 requirements of < 100 CFU/ml bioburden and < 0.5 EU/ml endotoxin (LAL). Results of this testing have documented that the proposed NxStage PureFlow SL with 96-hour MTU time is substantially equivalent to the predicate device and is suitable for the labeled indications for use.
{2}------------------------------------------------
Image /page/2/Picture/1 description: The image shows the seal for the Department of Health & Human Services USA. The seal is circular and contains the words "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" around the perimeter. In the center of the seal is an abstract image of an eagle.
Food and Drug Administration 10903 New Hampshire Avenue Document Mail Center - WO66-G609 Silver Spring, MD 20993-0002
Ms. Mary Lou Stroumbos Sr. Regulatory Affairs Associate NxStage Medical. Inc. 439 South Union Street, 5th Floor LAWRENCE MA 01843
SEP 1 9 2JU
Re: K11174
Trade/Device Name: NxStage® PureFlow™ SL Regulation Number: 21 CFR§ 876.5820 Regulation Name: Hemodialysis system and accessories Regulatory Class: II Product Code: FKR Dated: August 26, 2011 Received: August 29, 2011
Dear Ms. Stroumbos:
We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting of medical device-related
{3}------------------------------------------------
adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (OS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please go to http://www.fda.gov/AboutFDA/CentersOffices/CDRH/CDRHOffices/ucm115809.htm for the Center for Devices and Radiological Health's (CDRH's) Office of Compliance. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to
http://www.fda.gov/MedicalDevices/Safety/ReportalProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.
You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.
Sincerely yours,
Hubert H Humphrey
Herbert P. Lerner, M.D., Director (Acting) Division of Reproductive. Gastro-Renal and Urological Devices Office of Device Evaluation Center for Devices and Radiological Health.
Enclosure
{4}------------------------------------------------
#### INDICATIONS FOR USE
| 510(k) Number (if known): | K111174 |
|---------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Device Name: | NxStage® PureFlow™ SL |
| Indications for Use: | The NxStage PureFlow SL module is an optional<br>accessory to the NxStage System One™ that prepares<br>dialysate for use during hemodialysis, as prescribed by the<br>physician. |
Prescription Use × (Part 21 CFR 801 Subpart D) AND/OR
Over-The-Counter Use (21 CFR 807 Subpart C)
(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)
Concurrence of CDRH, Office of Device Evaluation (ODE)
Aayú M. When
Page 1 of 1
(Division Sign-Off)
Division of Reproductive, Gastro-Renal, and
Urological Devices
510(k) Number K111174
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
Where do you find a device's intended use without opening the PDF?
Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
What does the AI Performance sub-table show, and why is it useful?
Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
What does the side-by-side PDF viewer mode do?
Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
8. Chart view
Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
10. Embeddings: the galaxy map
The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.
