MR CONDITIONAL CUP ELECTRODE, MR CONDITIONAL WEBB ELECTRODE

• K Number: K130287
• Device Name: MR CONDITIONAL CUP ELECTRODE, MR CONDITIONAL WEBB ELECTRODE
• Manufacturer: RHYTHMLINK INTERNATIONAL, LLC
• Date Cleared: 2013-05-30 ( 114 days)
• Product Code: GXY
• Regulation Number: 882.1320
• Type: Traditional
• Panel: NE
• Reference & Predicate Devices: N/A

Intended Use

The MR Conditional Cup and Webb Electrodes are intended for use in the recording of the Electroencephalogram (EEG), the evoked potential (EP), or as a ground and reference in an EEG or EP recording. This device is non-sterile for Single Patient Use Only and may remain on the patient in a MRI environment under specific conditions.

Device Description

The design of the Rhythmlink Disposable MR Conditional Cup and Webb electrodes are identical to the existing Cup and Webb electrodes used to record neurological activity during electroencephalograph (EEG) and evoked potential (EP) procedures. The device consists of a disk shaped electrode with a Cup or Webb shape ABS molded plastic and coated with Ag/AgCl. The Electrode is permanently attached to a leadwire using a validated crimp process and is covered with a biocompatible heat shrink material. The Cup and Webb electrodes are connected to a 10cm (100mm) long multi-strand copper cable with PVC insulation over the tinned copper conductors. An accessory cable is supplied to attach to the 10cm electrode leadwire to create 1.0 to 3.0 meter traditional lengths to attach to the monitoring equipment. This accessory cable is labeled "MR Unsafe" and is NOT intended to be in the MR environment. The significantly shorter 10cm lead wire is permanently attached to the electrode and reduces the effects of matching the electrode leadwire length to the wave length and reduces the likelihood of an increase in the heating effect. This will enable users to leave the electrodes in place during magnetic resonance imaging (MRI) procedures.

AI/ML Overview

This is a 510(k) summary for a medical device: MR Conditional Cup Electrode and MR Conditional Webb Electrode. Note that 510(k) clearances are for demonstrating substantial equivalence to a predicate device, not necessarily for proving absolute safety and effectiveness through extensive clinical trials. Therefore, the details provided often focus on bench testing and comparisons to established devices rather than large-scale clinical studies.

Here's an analysis of the provided information:

Acceptance Criteria and Device Performance

The document does not explicitly present a table of acceptance criteria with corresponding performance metrics in a pass/fail format typical for performance studies. Instead, it describes various tests and concludes that the device performs "equal to the predicate devices" and "did not raise any additional questions of safety and efficacy."

However, we can infer some criteria and reported performance from the "Summary of Non-Clinical Tests":

Acceptance Criteria (Inferred from testing)	Reported Device Performance
Mechanical Performance:
Leadwire Pull Strength	Confirmed to perform equal to predicate devices.
Electrical Performance:
Resistance of Completed Assembly	Confirmed to perform equal to predicate devices.
MR Safety (Heating Effect):
Max Temperature Increase (worst-case scenario) at electrode-skin interface	0.4°C
MR Safety (Torque and Artifact):	Minimally affected by the magnetic field; torque and artifact testing and measuring were performed and results were acceptable.
Manufacturing Consistency:	No changes in manufacturing processes affecting performance were found compared to predicate devices.

Study Information

1. Sample Size used for the test set and data provenance:

   • Test Set Sample Size: The document does not specify a distinct "test set" in terms of patient samples. Instead, it refers to numerical simulations and non-simulated physical testing using phantoms.
     • Numerical Simulations: Involved three different electrode types (Cup, Webb, PressOn™) with various configurations (e.g., "Z" axis with two electrodes, different head sizes and populations) and field strengths (1.5T [68 MHZ] and 3.0T [128MHZ]). The exact number of simulation runs or parameters is not quantified as a "sample size" in the traditional sense, but it was comprehensive enough to determine a "worst-case configuration."
     • Physical Testing: Used phantoms "in accordance with appropriate ASTM Standards." The number of phantoms or individual tests performed is not explicitly stated.
   • Data Provenance: The data is from bench testing and numerical simulations (conducted by MR:comp Services on behalf of Rhythmlink International), not human or animal subjects. Therefore, there is no direct country of origin for patient data, nor is it retrospective or prospective in the clinical sense.

2. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

   • This information is not provided as there was no "ground truth" derived from expert consensus on clinical data for a test set. The study relies on engineering and physics principles, simulation software (SIMCAD X with FDTD modeling), and ASTM standards for physical phantom testing.

3. Adjudication method for the test set:

   • Not applicable. There was no human expert adjudication of results for a test set derived from clinical images or data, as this was a bench and simulation study.

4. If a multi-reader multi-case (MRMC) comparative effectiveness study was done:

   • No. An MRMC comparative effectiveness study was not performed. This type of study involves multiple human readers evaluating cases with and without AI assistance, which is not relevant to the magnetic resonance compatibility testing of an electrode.

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

   • Not applicable in the typical sense of an "algorithm." The "device" being evaluated is a physical electrode, not a diagnostic algorithm. The safety evaluation was performed in a standalone manner on the device itself through simulations and physical tests, without a human-in-the-loop interacting with the device for performance measurement.

6. The type of ground truth used:

   • The "ground truth" for the MR safety evaluation was based on physical measurements (temperature, torque, artifact) and validated numerical simulation models (SIMCAD X with FDTD modeling, referencing ASTM Standards for phantoms) that predict the behavior of the electrode in an MRI environment. It's an engineering and physics-based ground truth.

7. The sample size for the training set:

   • Not applicable for this device and study type. There was no "training set" in the context of machine learning or AI algorithms, as this is a physical medical device.

8. How the ground truth for the training set was established:

   • Not applicable. See point 7.

Regulation Number and Section

§ 882.1320 Cutaneous electrode.

(a)
Identification. A cutaneous electrode is an electrode that is applied directly to a patient's skin either to record physiological signals (e.g., the electroencephalogram) or to apply electrical stimulation.(b)
Classification. Class II (performance standards).