(267 days)
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.
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.
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.
§ 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).