The Precision Flow OSV II is an implantable system used in the treatment of patients with hydrocephalus, to shunt CSF from the ventricles to the peritoneal cavity or other appropriate drainage site such as the heart's right atrium.

Device Description

The Orbis Sigma Valve and the Precision Flow OSV IT are both variable resistance valves that manuain a drainage rate close to the rate of CSF secretion (~ 20 ml/h) within the physiological range of intracranial pressure. The mechanism incorporates a safety pressure relief mode to prevent accidental intracranial hypertension. The principle of operation consists of a flow restricting diaphragm, a seat, and a notched pln. The diaphragm, held between two polysulfone parts of the casing, reacts to variations in pressure. A synthetic ruby seat is inserted into the center of the diaphragm. The clearance between the seat aperture and the notched synthetic ruby nin varies depending on seat movements along the pin as pressure varies. Precision Flow OSV II and Orbis Sigma Valve are characterized by the same three stages of operation, that are defined below : Stage / - Low Differential Pressure (DP), Stage II - Flow Regulation, Stage III - Pressure Rellef Mode.

AI/ML Overview

This document, K971799, is a 510(k) premarket notification for the Precision Flow OSV II, a Central Nervous System (CNS) Fluid Shunt System. The primary method used to demonstrate safety and effectiveness, and thus meet acceptance criteria, is through substantial equivalence to a predicate device, the Cordis Orbis Sigma Valve.

Here's a breakdown of the requested information:

1. Table of Acceptance Criteria and Reported Device Performance

The core "acceptance criteria" are the performance specifications of the predicate device, which the Precision Flow OSV II claims to replicate. The study described focuses on demonstrating that the new device's performance is identical to the predicate device.

Performance Attribute	Acceptance Criteria (from Predicate)	Reported Device Performance (Precision Flow OSV II)
Intended Use	Treatment of hydrocephalus, shunting CSF from ventricles to peritoneal cavity or other appropriate drainage site.	Identical to predicate device.
Operating Principle	Variable resistance valve maintaining drainage rate close to CSF secretion rate (~20 ml/h) within physiological ICP range, with safety pressure relief mode.	Identical to predicate device.
Hydrodynamic Specifications	- Stage I (Low Differential Pressure): Flow rate 5-18 ml/hr at DP 30-120 mm H2O.	Identical to predicate device.
	- Stage II (Flow Regulation): Flow rate 18-30 ml/hr at DP 120-300 mm H2O.	Identical to predicate device.
	- Stage III (Pressure Relief Mode): Rapid flow rate for IVP normalization, then reverts to Stage II or I.	Identical to predicate device.
Biocompatibility	Documented biocompatibility of materials in predicate devices.	No new issues raised; materials are the same as predicate devices.
Design, Materials, Manufacturing Methods, Specifications	Equivalent to predicate device.	Equivalent to predicate device.

2. Sample Size Used for the Test Set and Data Provenance

This submission does not describe a clinical study with a "test set" in the sense of a new patient cohort for the Precision Flow OSV II. Instead, it relies on the established performance of its predicate, the Orbis Sigma Valve.

Sample Size for Test Set: Not applicable. The "test" is a comparison to the established specifications of the predicate device, not an independent clinical trial on a new set of patients for the Precision Flow OSV II.
Data Provenance: The hydrodynamic specifications and operating principles are derived from the Orbis Sigma Valve. The document references a clinical study and use over more than seven years validating the concept for the Orbis Sigma Valve (Sainte Rose, Hooven MD, Hirsch JF: A new approach in the treatment of hydrocephalus. J Neurosurg. 86:213-226, 1987). This suggests retrospective data from clinical use of the predicate, likely from various international locations where the device was marketed.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications

Number of Experts: Not explicitly stated for establishing "ground truth" for the new device.
Qualifications of Experts: The "concept of the flow regulation linked to the OSV hydrodynamic specifications has been developed by Pr C. Sainte Rose M.D." This indicates that the initial specifications were developed by a medical professional. For the 510(k) submission, FDA reviewers (Celia M. Witten, Ph.D., M.D., Director, Division of General and Restorative Devices, Office of Device Evaluation) acted as experts in reviewing the claim of substantial equivalence.

4. Adjudication Method for the Test Set

Not applicable, as there was no "test set" requiring adjudication in the context of a new clinical study for the Precision Flow OSV II. The device's performance is asserted as identical to, and therefore meeting the established performance of, its predicate.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done

No, an MRMC comparative effectiveness study was not done. This device is a physical medical implant (shunt), not an imaging or diagnostic AI tool that would typically involve a multi-reader study. The evaluation focuses on physical and hydrodynamic equivalence.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Study Was Done

Not applicable. This device is a physical CNS shunt system and does not involve an algorithm or AI.

7. The Type of Ground Truth Used

The "ground truth" for the predicate device's performance was established through:
- Expert Consensus/Development: The concept developed by Pr C. Sainte Rose M.D.
- Clinical Studies and Use: "Validated by clinical studies and use over more than seven years" (for the predicate Orbis Sigma Valve). This implies outcomes data from a real-world patient population.
For the Precision Flow OSV II, the ground truth is that its design, materials, manufacturing methods, and performance specifications are identical/equivalent to this established predicate.

8. The Sample Size for the Training Set

Not applicable. There is no training set in the context of machine learning or AI, as this is a physical medical device. The "training" for its design and performance would be the extensive research, development, and clinical validation conducted for its predicate device over several years.

9. How the Ground Truth for the Training Set Was Established

Not applicable, as there is no "training set" in the AI sense. The "ground truth" for the predicate device's efficacy and performance, which forms the basis for demonstrating equivalence for the Precision Flow OSV II, was established through a combination of:

Expert Design and Theoretical Principles: Pr C. Sainte Rose M.D.'s development of the flow regulation concept and hydrodynamic specifications.
Clinical Validation: "Clinical studies and use over more than seven years" for the predicate Orbis Sigma Valve, which would have involved patient outcomes data to confirm the device's intended therapeutic effect and performance in vivo.

Summary

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FEB -6 1998

SUMMARY OF SAFETY AND EFFECTIVENESS

1. Trade (proprietary) Name

Precision Flow™ OSV II

2. Common/Classification Name

Central Nervous System (CNS) Fluid Shunt System

3. Applicant's Name and Address

Elekta Implants S.A. Parc de Sophia Antipolis 2905 Route des Dolines F-06921 Sophia Antipolis, France

4. Classification

This device is classified as Class II (21 CFR 882.5550).

5. Predicate Devices

Cordis Orbis Sigmad Valve Cordis Omnishunt® System Cordis Polypropylene Connectors Cordis Ventricular Antechamber Cordis Straight or Finned Ventricular Catheters (with radiopaque dots)

6. Performance Standards

No applicable performance standards have been established by FDA under section 514 of the Food, Drug and Cosmetic Act.

7. Intended Use and Device Description

The Precision Flow OSV II intended use is the same as the Orbis Sigma Valve: it is an implantable system used in the treatment of patients with hydrocephalus, to shunt CSF from the ventricles to the peritoneal cavity or other appropriate drainage site such as the heart's right atrium.

K971799

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The principle of operation consists of a flow restricting diaphragm, a seat, and a notched pln. The diaphragm, held between two polysulfone parts of the casing, reacts to variations in pressure. A synthetic ruby seat is inserted into the center of the diaphragm. The clearance between the seat aperture and the notched synthetic ruby nin varies depending on seat movements along the pin as pressure varies (see Section 4). Precision Flow OSV II and Orbis Sigma Valve are characterized by the same three stages of operation, that are defined below :

Stage / - Low Differential Pressure (DP)

This stage begins when the flow rate through the valve reaches 5ml/hr (DP will be between 30 and 80 mm H20). The valve remains in Stage I with CSF flow rates up to 18 ml/hr (DP will be hetween 40 and 120 mm H20).

Stage II - Flow Regulation

When the DP increases, the valve operates as a variable resistance flow regulator. At DP ranges between 120 and 300 mm H,0, the valve restricts flow between 18 and 30 ml/hr.

Stage III - Pressure Rellef Mode

Should the intraventricular pressure (IVP) elevate abruptly, the shunt operates in a rapid flow rate mode to facilitate NP normalization. The valve then reverts to Stage II or I, depending upon conditions.

The concept of the flow regulation linked to the OSV hydrodynamic specifications has been developed by Pr C. Sainte Rose M.D. ( Sainte Rose, Hooven MD, Hirsch JF: A new approach in the treatment of hydrocephalus. J Neurosurg. 86:213-226, 1987- attached to this section).

This concept has been validated by clinical studies and use over more than seven years (Refer to the OSV Premarket Notification K913636 and Post-Market Surveillance report dated June 3, 1994).

8. Biocompatibility

The biocompatibility of the materials used in the manufacture of the Precision Flow OSV II has been documented in the Premarket Notifications of the Orbis Sigma Valve, the Cordis Ventricular Antechamber and the Cordis Straight or Finned Ventricular Catheters. No new issues related to biocompatibility are raised.

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9. Summary of Substantial Equivalence':

The indications, contraindications, operating principle, and performance specifications of the Precision Flow OSV II are identical to those of the predicate Orbis Sigma Valve. The design, materials, manufacturing methods and specifications of the Precision Flow OSV II are equivalent to those of the predicate devices and do nul raise any new issues relating to safety and offectiveness for its intended use.

Any statement made in conjunction with this submission regarding substantial courvalence to any other product only relates to whether the product can be lawfully marketed without premarket approval or reclassification and is not to be interpreted as an admission or used as evidence in patent infringement litigation. As the Commissioner of the FDA has indicated, ". . a determination of substantial equivalence under the Federal Food, Drug, and Cosmetic Act relates w the fuct that the product can lawfully be marketed without premarket approval or reclassification. This determination is not intended to have any bearing whatsoever on the resolution of patent infringement suits." 42 Fed. Reg. 42,520 et seq. (1977).

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Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

FEB - 6 1998

Ms. Barbara Ramseyer RA Consultant Elekta Implants, SA 6011 Cellini Street Coral Gables, Florida 33146

Re: K971799

Trade Name: Precision Flow OSV II Regulatory Class: II Product Code: JXG Dated: December 19, 1997 Received: December 23, 1997

Dear Ms. Ramseyer:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to 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). 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.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the …… current Good Manufacturing Practice requirements , as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic (QS) inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for

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Page 2 - Ms. Ramseyer

devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4595. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsmamain.html".

Sincerely yours.

to coeepto

Celia M. Witten, Ph.D., M.D. Director Division of General and Restorative Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Precision Flow OSV II

火971799 510(k) Number:

Device Name: Precision Flow ™OSV II

Indications for Use:

The Precision Flow OSV II is an implantable system used in the treatment of patients The Frecision I Now OOT in is an implanticles to the poritoned cavity or other appropriate drainage site such as the heart's right atrium.

Concurrence of CDRH, Office of Device Evaluation (ODE)

(Division Sign-Off)
Division of General Restorative Devices
510(k) Number	K971799

Prescription or Over the Counter Use
(Per CFR 801.109)
(Optional Format 1-2-96)

Prescription Use
(Per 21 CFR 801.109)

Regulation Number and Section

§ 882.5550 Central nervous system fluid shunt and components.

(a)
Identification. A central nervous system fluid shunt is a device or combination of devices used to divert fluid from the brain or other part of the central nervous system to an internal delivery site or an external receptacle for the purpose of relieving elevated intracranial pressure or fluid volume (e.g., due to hydrocephalus). Components of a central nervous system shunt include catheters, valved catheters, valves, connectors, and other accessory components intended to facilitate use of the shunt or evaluation of a patient with a shunt.(b)
Classification. Class II (performance standards).