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The Polaris® Adjustable Pressure Valves are indicated to drain cerebrospinal fluid (CSF) for the management of hydrocephalus.

The Polaris® Adjustable Pressure Valve is an implantable device designed for the treatment of hydrocephalus in adult and pediatric patients by shunting, thereby providing continuous, controlled intraventricular pressure and CSF drainage from the cerebral ventricles. Intraventricular pressure is maintained at a constant level by the device's ball- in-cone valve seat design, and the value is pressure-adjustable transcutaneously. Drainage is directed to the abdominal cavity or to the right atrium of the heart.

The basic settings of the Polaris® Valve Models SPV, SPVA, and SPVB are 30, 70, 110, 150 and 200. Adjustments to intermediate pressures are made manually in 40-50 mm Hz0 increments (decrements) in three operating ranges, low pressure (LP =30 mm Hz0), medium pressure (MP = 110 mm H20), and high pressure (HP = 200 mm H20).

The basic settings of the Polaris® SPV-140 Valve are 10, 40, 80, 110 and 140 mm H₂0; adjustments to intermediate pressures are made manually in 30-40 mm H20 increments (decrements).

The basic settings of the Polaris® SPV-300 Valve are 50, 100, 150, 220 and 300 mm H₂0; adjustments to intermediate pressures are made manually in 50-80 mm H20 increments (decrements).

The basic settings of the Polaris® SPV-400 Valve are 80, 150, 230, 330 and 400 mm H-0; adjustments to intermediate pressures are made manually in 70-100 mm H20 increments (decrements).

The specific feature of the self-locking rotor-shuttle micro-magnet system of the passive Polaris® SPV Valve is that the adjustment position of each pressure setting cannot be changed by a unidirectional magnetic field. A domestic field or an exposure to MRI attracts the shuttles in the same direction and thus cannot unlock them simultaneously, therefore the rotor cannot be mobilized and the pressure setting remains fixed and constant.

The provided text describes specific verification and validation testing for the Polaris® Adjustable Pressure Valves related to their MRI compatibility, rather than a clinical study evaluating the device's functional performance in treating hydrocephalus. Therefore, some of the requested information, such as effect size of human readers improving with AI, sample size for training sets, or number of experts for ground truth, is not applicable or available in the given text.

Here's the information that can be extracted from the provided text:

Acceptance Criteria and Device Performance for MRI Compatibility

The acceptance criteria are implicitly met if the test results "supported the MRI labeling statements for exposure of the Polaris Adjustable Pressure Valves to a 3-Tesla MRI environment." The specific quantitative thresholds for these criteria are not detailed in the provided text.

Study Details:

1. Sample size used for the test set and the data provenance: Not specified. The testing was conducted on "Polaris Adjustable Pressure Valves," implying a physical sample of devices, but the exact number or how they were selected is not provided. No patient data (retrospective or prospective) was used for this specific testing.

2. Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable. The ground truth for this engineering verification study would be based on validated physical measurements and performance standards, not expert clinical interpretation.

3. Adjudication method (e.g. 2+1, 3+1, none) for the test set: Not applicable. This was a technical verification and validation study, not a clinical study involving adjudication of clinical findings.

4. 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: Not applicable. This study focuses on the device's physical compatibility with MRI, not AI assistance for human readers.

5. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Not applicable. This is not an algorithm-based device.

6. The type of ground truth used: For magnetic field interactions, heating, and artifacts, the ground truth would be based on established engineering standards and validated measurement techniques (e.g., temperature probes for heating, specific protocols for artifact assessment). For the functional aspects, the ground truth would be the device's functional specifications (e.g., pressure settings) before and after MRI exposure, measured using calibrated equipment.

7. The sample size for the training set: Not applicable. This is a physical device testing, not a machine learning study requiring a training set.

8. How the ground truth for the training set was established: Not applicable.

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