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The patient magnet is used to close the reed switch of a pulse generator when held above the reed switch, 1 inch from the generator's surface, and oriented with the magnet's axis parallel to the longitudinal axis of the reed switch.

The patient magnet is used daily to check that the pulse generator battery is working. When you pass or hold the magnet over the pulse generator, a reed switch inside the pulse generator closes like a gate. When the magnet closes the switch, the normal signal (stimulation) cannot pass, and the pulse generator is temporarily turned OFF. When the magnet is removed, the switch (gate) opens immediately, and the pulse generator is turned back ON and can stimulate again.

The patient magnets are made from Neodymium grade 35 (NdFeB-35) and the entire surface of the magnet is coated with either polypropylene copolymer. The magnet is 1.48 in. x 0.195 in; 50 gauss (G) minimum magnetic flux density at a distance of 1 inch from its surface. Also supplied with Patient Magnet, are a watchband and a belt-clip that allows that patient to wear the magnet on the wrist like a watch or clipped on belt like a pager for easy deployment.

Here's the analysis of the provided text regarding the acceptance criteria and study for the Cyberonics Patient Magnet:

Acceptance Criteria and Device Performance (Based on Intended Use):

Study Information:

The provided document (K092364) is a 510(k) summary for a Class I medical device (Cyberonics Patient Magnet). For Class I devices, particularly those that are substantially equivalent to existing predicate devices, a formal clinical study with detailed performance metrics and ground truth establishment is typically not required or presented in the 510(k) summary.

The primary method for demonstrating safety and effectiveness for such devices is through substantial equivalence to a predicate device, as highlighted in the document. This relies on demonstrating that the new device has the same intended use and similar technological characteristics (e.g., materials, magnetic properties) as a legally marketed predicate device.

Therefore, many of the specific questions regarding a clinical study (sample size, experts, adjudication, MRMC, standalone performance, ground truth for training/test sets) are not applicable or not detailed in this type of regulatory submission.

Here's how to address the specific points based on the available information:

• 2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective):

  • Not Applicable / Not Provided. The document does not describe a formal clinical test set or study with explicit sample sizes. The claim of performance is based on the device's physical specifications and its substantial equivalence to a predicate device.

• 3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g., radiologist with 10 years of experience):

  • Not Applicable / Not Provided. There is no indication of a test set requiring expert ground truth establishment.

• 4. Adjudication method (e.g., 2+1, 3+1, none) for the test set:

  • Not Applicable / Not Provided. No test set or expert assessment is described.

• 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. This is not an AI-enabled device. The document describes a simple patient magnet.

• 6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:

  • No. This is not an algorithm-based device. Performance is inherent to the physical properties of the magnet.

• 7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

  • Not Applicable / Not Provided. Ground truth is not established through these means for this type of device. The "ground truth" for this device's function is its physical ability to generate a sufficient magnetic field to close a reed switch as specified.

• 8. The sample size for the training set:

  • Not Applicable / Not Provided. There is no training set for this device.

• 9. How the ground truth for the training set was established:

  • Not Applicable / Not Provided. There is no training set for this device.

Summary of Approach (Implied by 510(k) Summary):

The device's performance regarding its ability to close a reed switch at a specific distance and orientation is a direct consequence of its physical design (material, dimensions, stated magnetic flux density). For a Class I device like a patient magnet, the "proof" it meets acceptance criteria (its intended use) comes from:

1. Engineering specifications and measurements: The stated "50 gauss (G) minimum magnetic flux density at a distance of 1 inch from its surface" is a key performance metric that demonstrates its capability.
2. Substantial Equivalence: The primary regulatory pathway for this device, which relies on demonstrating the new device is as safe and effective as a legally marketed predicate device (Pacesetter Systems, Pacemaker Test Magnet - K813153) that performs the same function. This implies that the predicate device has already demonstrated its safety and effectiveness for this function.

In essence, for this specific device, the "study" is the inherent engineering design and the comparison to an already approved equivalent product, rather than a clinical trial or AI validation study.

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