(194 days)
The HP Valve System is an implantable device that provides constant intraventricular pressure and drainage of cerebrospinal fluid (CSF) for the management of hydrocephalus.
The HP Valve System is a hydrocephalus shunt designed to allow the surgeon to change the valve operating pressure without surgical intervention. Intraventricular pressure is maintained at a constant level by the device's rubyball-in-cone valve seat design. The center of a flat spring is attached to a fixed fulcrum, with one end resting on the ruby ball and the other end resting on an eighteen position spiral staircase shaped cam that rotates on a titanium pivot. When the cam rotates the tension on the spring changes as the distal end of the spring moves up or down the cam. The operating pressure of the valve is thereby adjusted. During programming, the programmer transmits a coded magnetic signal to the device, causing the cam to rotate. The device has 18 pressure settings, ranging from 30mm to 200mm H20, in 10mm increments.
The provided text describes the HP Valve System, a hydrocephalus shunt, and its journey through FDA 510(k) approval in 1998. It references various tests and a clinical trial to demonstrate substantial equivalence to a predicate device. However, the document does not present explicit "acceptance criteria" for device performance in a numerical or categorical format, nor does it detail a study that directly "proves the device meets the acceptance criteria" with specific performance metrics. Instead, it describes a substantial equivalence claim based on various forms of testing and a clinical trial.
Therefore, the following information is extracted and inferred from the provided text as much as possible, with explicit notes on what is not available.
1. Table of Acceptance Criteria and Reported Device Performance
As explicit quantitative acceptance criteria are not stated in the document, this table will summarize the types of testing performed and the general conclusions regarding device performance, as described in the "Device Testing Summary" and the FDA's clearance letter.
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Biocompatibility: Device materials are safe for biological contact. | Directly Met: "Biocompatibility tests were performed per the Tripartite Biocompatibility Guidance for Medical Devices and ISO 10993 Biological Testing of Medical and Dental Materials and Devices. Testing results demonstrated that the device materials are biocompatible." |
| Performance (Mechanical/Functional): Device functions as intended through various operational and stress tests. | Directly Met: "Performance testing was conducted per and complies with the applicable sections of ASTM F647-94 - Standard Practice for Evaluating and Specifying Impantable Shunt Assemblies for Neurosurgical Applications. Performance testing included the following areas: Reprogramming, Fatigue, Corrosion, MRI, Wet Pressure and Programmer Evaluation. Testing results demonstrated the suitability of the device for its intended use." (Specific quantitative performance metrics or thresholds for each test, which would represent acceptance criteria, are not provided). |
| Clinical Equivalence (Safety & Effectiveness): Device performs as well as and is as safe and effective as currently marketed predicate devices. | Directly Met: "A controlled, randomized, clinical trial was conducted to support a claim of substantial equivalence. 377 patients were enrolled and followed for two years. Results indicated that the HP Valve System performs as well as and is as safe and effective as currently marketed hydrocephalus shunt systems." (Specific clinical endpoints, metrics, or statistical non-inferiority margins, which would represent acceptance criteria, are not provided). |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: For the clinical trial, 377 patients were enrolled. The document does not specify if this entire group represents a "test set" solely for evaluation or if it was the entire study population.
- Data Provenance: The document does not explicitly state the country of origin. Given the submitter's location (Raynham, MA) and the FDA clearance process, it is highly probable the data is largely from the United States or comparable regulatory environments. The clinical trial was a prospective study ("followed for two years").
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not provide details on the number or qualifications of experts specifically used to establish ground truth for the clinical trial data. Clinical trials typically involve physicians and other medical professionals responsible for patient diagnosis, treatment, and outcome assessment, which implicitly serve as the "ground truth" for clinical effectiveness and safety measurements.
4. Adjudication Method for the Test Set
The document does not specify any adjudication method (e.g., 2+1, 3+1, none) for the clinical trial's outcomes or safety data. In clinical trials, outcome data is typically collected through standardized protocols and reviewed by study investigators and potentially independent monitors, but a formal adjudication process beyond standard data review is not mentioned.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
- No MRMC study was done. This device is a mechanical medical implant (hydrocephalus shunt), not an AI-powered diagnostic or assistive tool for human readers. Therefore, the concept of "human readers improve with AI vs. without AI assistance" is not applicable.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
- No standalone algorithm performance study was done. As mentioned, this is a mechanical device, not an algorithm.
7. The Type of Ground Truth Used
- Clinical Outcomes Data: For the clinical trial, the ground truth was established through patient clinical outcomes and safety profiles over two years, compared to currently marketed hydrocephalus shunt systems. This would include metrics related to shunt function, complications, revisions, and patient well-being, as assessed by treating physicians and follow-up examinations.
- Engineering/Physical Standards: For the performance testing, the ground truth was established by adherence to ASTM F647-94 and internal engineering specifications, verifying mechanical and functional properties.
- Biocompatibility Standards: For biocompatibility, the ground truth was established by compliance with ISO 10993 and Tripartite Biocompatibility Guidance, confirming material safety.
8. The Sample Size for the Training Set
- Not applicable for this device. This is a mechanical medical device, not an AI/machine learning model, so there is no "training set." The design and manufacturing would be based on engineering principles and preclinical testing, not data training.
9. How the Ground Truth for the Training Set was Established
- Not applicable for this device. As there is no "training set" for an algorithm, there is no ground truth established for it.
§ 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).