(208 days)
Layer 7-T cortical electrodes are intended for temporary (less than 30 days) use with recording, monitoring, and stimulation equipment for the recording, monitoring, and stimulation of electrical signals on the surface of the brain. The electrodes may be placed in either open or burr hole procedures with the optional use of standard imaging techniques such as intraoperative x-ray, fluoroscopy, and computerized tomography (CT).
The Layer 7-T is intended for temporary (less than 30 days) use with recording, monitoring, and stimulation equipment for the recording, monitoring, and stimulation of electrical signals on the surface of the brain. The electrodes may be placed in either open or burr hole procedures with the optional use of standard imaging techniques such as intraoperative x-ray, fluoroscopy, and computerized tomography (CT).
The overall Layer 7-T consists of a sterile thin film 1024-electrode array connected to a more rigid PCB package (known as the headstage) with ribbon cables. Each ribbon cable connects to 64 channels from the electrode array. There are a total of 16 ribbon cables in the headstage, connecting 1024 electrodes on the array. The device is also provided with an intermediary yoke cable that connects the ribbon cables from the Layer 7-T headstage to standard EEG equipment via 64 standard DIN connectors. A yoke stand is also provided as an optional accessory that allows up to 16 yokes to be stacked. Surgical accessories are provided with the array and are intended to aid in deployment of the array.
The system allows the surgeon to place electrode arrays on the surface of the brain through burr holes. The inserted portion of the device can be retrieved following use by pulling the electrode array through the burr hole.
The thin film electrode array is designed to operate in a fashion identical to the currently used ECoG arrays, in that it is to be placed on the surface of the brain to interface with brain tissue through electrical recording and stimulation.
The electrode array consists of a polyimide substrate with platinum electrodes and associated electrically connecting traces and another layer of polyimide on top. A polyimide pocket is adhered via silicone to the backside of the electrode array tip. The array also contains gold radiopaque markers embedded in the silicone pocket adhesive. A rigid stainless steel radiopaque stylet is temporarily placed in the pocket during electrode array deployment.
The overall Layer 7-T system, including the yoke, is intended for single use only. The Layer 7-T is a passive device and only receives power from a connected FDA-cleared EEG system. It does not have any wireless capabilities and does not contain any software. It is not MRI-compatible. It is only intended for use in a professional healthcare environment.
The provided text is a 510(k) summary for a medical device called "Layer 7-T," a cortical electrode. While it details numerous performance tests, biocompatibility studies, electrical safety, human factors, and animal testing, it does not describe a study involving human-in-the-loop performance with an AI component or any study that would require acceptance criteria related to diagnostic accuracy, sensitivity, specificity, or reader improvement.
The document states: "The Layer 7-T is a passive device and only receives power from a connected FDA-cleared EEG system. It does not have any wireless capabilities and does not contain any software." This clearly indicates that the device itself is a passive hardware component and does not incorporate AI or any form of software that analyzes or interprets data to provide a diagnostic or assistive output that would require a "study that proves the device meets the acceptance criteria" in the context of AI performance.
Therefore, I cannot provide the requested information regarding AI acceptance criteria or a study proving device performance in that context, as the provided document explicitly states the device does not contain software or AI.
However, I can extract the general "performance data" that demonstrates the device's safety and effectiveness relative to its predicate, as described in the document.
General Performance Data and Acceptance (Based on Equivalence to Predicate)
The acceptance criteria for the Layer 7-T are implicitly defined by its ability to demonstrate substantial equivalence to the predicate device (Ad-Tech Subdural Electrodes, K191186) through various non-clinical tests. The goal is to show that it is "as safe and effective" as the predicate, even with minor technological differences.
1. Table of Acceptance Criteria and Reported Device Performance:
Since there's no AI or diagnostic software, the "acceptance criteria" for the device relate to fundamental device properties, material safety, and functional performance, with the implicit criterion being "Pass" compared to established standards or a predicate.
| Test/Parameter | Acceptance Criteria (Implicit from "Passed") | Reported Device Performance |
|---|---|---|
| Dimensional Measurements | Conform to hardware specifications by measurement and visual assessment. | Pass |
| Durability | Function safely and effectively under normal use conditions (mechanical testing). | Pass |
| Electrochemical Performance | Conductive properties appropriate for intended use; electrical continuity. | Pass |
| Platinum Dissolution Testing | Level of platinum released following stimulation protocol is acceptable. | Pass |
| Signal-to-Noise Ratio Testing | SNR comparable to the predicate. | Pass |
| Reliability | Maintain electrochemical and physical properties after accelerated aging. | Pass |
| EEG System Compatibility | Verification of signal acquired following cycling of connector. | Pass |
| Packaging Shelf Life | Pass ASTM F2096-11(2019) and ASTM D4169-23 standards. | Pass |
| Sterilization | Pass ISO 11135:2014 for ethylene oxide sterilization. | Pass |
| Biocompatibility | All assessed endpoints (Cytotoxicity, Sensitization, Irritation, Acute Systemic Toxicity, Material Mediated Pyrogenicity, Genotoxicity, Implantation Testing, Hemolysis, Chemical characterization/Toxicological Risk Assessment) are acceptable. | Results support biocompatibility. |
| Electrical Safety & EMC | Conform to IEC 60601-1 (various amendments), IEC 60601-1-2 (various amendments), IEC 80601-2-49:2018, and IEC TR 60601-4-2:2024. | Passed applicable clauses. |
| Human Factors | Usability validated per "Applying Human Factors and Usability Engineering to Medical Devices" guidance and ANSI AAMI HE75:2009. | All evaluations performed and support safety/effectiveness. |
| Animal Testing (GLP Study) | No adverse events specifically related to the Layer 7 cortical electrode array; similar cortical inflammatory response to predicate, subsiding by 6 weeks. | Confirmed biocompatibility; no ongoing neurotoxicity; similar inflammatory response to predicate. |
2. Sample Size Used for the Test Set and Data Provenance:
The document describes non-clinical bench testing and animal studies. There is no "test set" in the context of an AI model's performance on patient data.
- Bench Testing: Sample sizes are not explicitly stated for most bench tests (e.g., durability, electrochemical performance), but it's implied that sufficient samples were tested to demonstrate compliance.
- Animal Testing: 16 female Göttingen swine were used, divided into a 1-week and a 6-week implant duration cohort.
- Data Provenance: The animal study was a GLP (Good Laboratory Practices) study, indicating a controlled, prospective experimental setting. The origin of the animals is not specified beyond "Göttingen swine."
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications:
Not applicable, as this is neither an AI device nor does it involve a "test set" requiring expert-established ground truth in the diagnostic sense. The ground truth for biocompatibility and animal study outcomes would be established by qualified pathologists and veterinarians, but their specific number and qualifications are not detailed.
4. Adjudication Method for the Test Set:
Not applicable, as there's no AI model output requiring adjudication.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done:
No, an MRMC study was not performed. This type of study is typically used for AI-assisted diagnostic devices to assess the impact of AI on human reader performance, which is not relevant for this passive hardware device.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done:
Not applicable, as the device is a passive hardware component with no embedded algorithm or software for standalone performance evaluation beyond its physical and electrical characteristics.
7. The Type of Ground Truth Used:
- Bench Testing: Ground truth is based on engineering specifications, physical measurements, and adherence to international standards (e.g., ASTM, ISO, IEC).
- Animal Testing: Ground truth was established through neurological evaluations, gross and microscopic pathological analysis performed by qualified personnel (implied).
8. The Sample Size for the Training Set:
Not applicable, as there is no AI or machine learning model that requires a training set.
9. How the Ground Truth for the Training Set Was Established:
Not applicable, as there is no AI or machine learning model.
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March 30, 2025
Image /page/0/Picture/1 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). The logo consists of two parts: a symbol on the left and the FDA acronym with the full name of the agency on the right. The symbol on the left is a stylized representation of the Department of Health & Human Services seal. To the right of the seal is the FDA acronym in a blue square, followed by the words "U.S. FOOD & DRUG" in blue and "ADMINISTRATION" in a lighter blue.
Precision Neuroscience, Corp. Jayme Strauss Chief Clinical and Commercial Officer 5201 Great America Pkwy. Suite 432 Santa Clara, California 95054
Re: K242618
Trade/Device Name: Layer 7-T Regulation Number: 21 CFR 882.1310 Regulation Name: Cortical Electrode Regulatory Class: Class II Product Code: GYC Dated: February 27, 2025 Received: February 27, 2025
Dear Jayme Strauss:
We have reviewed your section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device"
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(https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).
Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30. Design controls; 21 CFR 820.90. Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review. the OS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.
All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rue"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advicecomprehensive-regulatory-assistance/unique-device-identification-system-udi-system.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.
For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).
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Sincerely,
Jay R. Gupta -S
Jay Gupta Assistant Director DHT5A: Division of Neurosurgical, Neurointerventional, and Neurodiagnostic Devices OHT5: Office of Neurological and Physical Medicine Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health
Enclosure
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Indications for Use
510(k) Number (if known) K242618
Device Name Layer 7-T
Indications for Use (Describe)
Layer 7-T cortical electrodes are intended for temporary (less than 30 days) use with recording, and stimulation equipment for the recording, and stimulation of electrical signals on the surface of the brain. The electrodes may be placed in either open or burr hole procedures with the optional use of standard imaging techniques such as intraoperative x-ray, fluoroscopy, and computerized tomography (CT).
Type of Use (Select one or both, as applicable)
| ☒ Prescription Use (Part 21 CFR 801 Subpart D) |
|---|
| ☐ Over-The-Counter Use (21 CFR 801 Subpart C) |
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510(k) SUMMARY
Precision Neuroscience, Corp.'s Layer 7-T
K242618
Submitter:
5201 Great America Pkwy Suite 432 Santa Clara, CA 95054 United States
Phone: (646) 771-5881
Contact Person: Jayme Strauss
Email Address: Jayme.Strauss@precisionneuro.io
Date Prepared: February 18, 2025
Name of Device: Layer 7-T
Common or Usual Name: Cortical electrode
Classification Name: Electrode, Cortical
Regulatory Class: 21 CFR 882.1310
Product Code: GYC
Predicate Device: K191186
Ad-Tech Medical Instrument Corporation
- Subdural Strip/Intraoperative Strip Electrode ●
- Subdural Grid/Intraoperative Grid Electrode ●
- Dual-Sided Interhemispheric Subdural Electrode ●
- Multi-Strip and Split Grid Subdural Electrode ●
- Intraoperative Mapping Grid Subdural Electrode ●
Device Description:
The Layer 7-T is intended for temporary (less than 30 days) use with recording, monitoring, and stimulation equipment for the recording, monitoring, and stimulation of electrical signals on the surface of the brain. The electrodes may be placed in either open or burr hole procedures with the optional use of standard imaging techniques such as intraoperative x-ray, fluoroscopy, and computerized tomography (CT).
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The overall Layer 7-T consists of a sterile thin film 1024-electrode array connected to a more rigid PCB package (known as the headstage) with ribbon cables. Each ribbon cable connects to 64 channels from the electrode array. There are a total of 16 ribbon cables in the headstage, connecting 1024 electrodes on the array. The device is also provided with an intermediary yoke cable that connects the ribbon cables from the Layer 7-T headstage to standard EEG equipment via 64 standard DIN connectors. A yoke stand is also provided as an optional accessory that allows up to 16 yokes to be stacked. Surgical accessories are provided with the array and are intended to aid in deployment of the array.
The system allows the surgeon to place electrode arrays on the surface of the brain through burr holes. The inserted portion of the device can be retrieved following use by pulling the electrode array through the burr hole.
The thin film electrode array is designed to operate in a fashion identical to the currently used ECoG arrays, in that it is to be placed on the surface of the brain to interface with brain tissue through electrical recording and stimulation.
The electrode array consists of a polyimide substrate with platinum electrodes and associated electrically connecting traces and another layer of polyimide on top. A polyimide pocket is adhered via silicone to the backside of the electrode array tip. The array also contains gold radiopaque markers embedded in the silicone pocket adhesive. A rigid stainless steel radiopaque stylet is temporarily placed in the pocket during electrode array deployment.
The overall Layer 7-T system, including the yoke, is intended for single use only. The Layer 7-T is a passive device and only receives power from a connected FDA-cleared EEG system. It does not have any wireless capabilities and does not contain any software. It is not MRI-compatible. It is only intended for use in a professional healthcare environment.
Intended Use / Indications for Use
Intended Use/Indications for Use:
Layer 7-T cortical electrodes are intended for temporary (less than 30 days) use with recording, monitoring, and stimulation equipment for the recording, monitoring, and stimulation of electrical signals on the surface of the brain. The electrodes may be placed in either open or burr hole procedures with the optional use of standard imaging techniques such as intraoperative x-ray, fluoroscopy, and computerized tomography (CT).
Indications for Use Comparison to Predicate:
The proposed intended use for the Layer 7-T and the intended use for the Ad-Tech Subdural Electrodes (K191186) are identical. Both devices intended for temporarily placement on the surface of the brain for stimulating the brain or recording the brain's electrical activity.
There are minor differences in the indications for use for the Layer 7-T and the indications for use of the Ad-Tech Subdural Electrodes. Both devices are indicated for temporary (less than 30 days) use with recording, monitoring, and stimulation equipment for the recording, and stimulation of electrical signals on the surface of the brain. The Layer 7-T indications state that the device may be placed in either open or burr hole procedures with the optional use of fluoroscopic imaging. This
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additional language in the indications for use for the Layer 7-T does not alter the intended effect of the device or create a new intended use. These differences in indications are representative of the difference in technological characteristics are supported by performance testing which demonstrates that the Layer 7-T electrodes are as safe and effective as the predicate.
Summary of Technological Characteristics:
Both the Layer 7-T and the Ad-Tech Subdural Electrodes are sterile, single-use electrical conductors that are temporarily placed on the surface of the brain. Both of these devices record and/or monitor the brain's electrical activity as well as stimulate the brain. Both devices also operate in a similar manner, which is by using provided cables to connect the device to an external commercially available EEG or cortical stimulation system for recording, monitoring or stimulating.
The Layer 7-T has several minor differences as compared to the predicate including: higher electrode count, smaller contact diameter and smaller electrode body surface area. The Layer 7-T electrode array is made of polyimide and the electrode contact material is made of platinum while the Ad-Tech Subdural Electrodes are made of silicone with a platinum/iridium electrode contact material. Unlike the predicate, the Layer 7-T electrode array is also designed with an integrated pocket on the underside of the array and is provided with its own surgical tools to aid in deployment. Lastly, the Layer 7-T incorporates a printed circuit board (PCB) bonded to the electrode array. The PCB does not raise any new safety or effectiveness questions compared to the predicate, as the PCB-electrode interface is outside the body and fully enclosed in biocompatible packaging material. The PCB board has no active electronic components, and functions solely as a conduit that directs signals from the brain to connectors during recording and use. These differences do not raise new questions of safety or effectiveness and are supported by bench and animal performance data which demonstrate that the Layer 7-T is as safe and effective as the Ad-Tech Subdural Electrodes
| Feature | Layer 7-T (Subject Device) | Ad-Tech SubduralElectrodes (K191186) | Comment |
|---|---|---|---|
| Indications forUse | Layer 7-T cortical electrodesare intended for temporary(less than 30 days) use withrecording, monitoring, andstimulation equipment forthe recording, monitoring,and stimulation of electricalsignals on the surface of thebrain. The electrodes maybe placed in either open orburr hole procedures withthe optional use of standardimaging techniques such asintraoperative x-ray,fluoroscopy, andcomputerized tomography(CT). | The Ad-Tech SubduralElectrodes(Strip/Intraoperative Strip,Grid/Intraoperative Grid, Dual-Sided Interhemispheric,MultiStrip and Split Grid,Intraoperative Mapping Grid)are intended for temporary (<30 days) use with recording,monitoring, and stimulationequipment for the recording,monitoring, and stimulation ofelectrical signals on thesurface of the brain. Therecording of electrical activitysupports definition of thelocation of epileptogenic fociand brain mapping. | The Layer 7-T includesadditional language onthe surgical procedureand the use of optionalimaging duringplacement of the array.This does not alter theintended effect of thedevice or create a newintended use. |
| Feature | Layer 7-T (Subject Device) | Ad-Tech SubduralElectrodes (K191186) | Comment |
| ClinicalApplication | Placed on the surface of thebrain to support recording,monitoring, and stimulation. | Placed on the surface of thebrain to support recording,monitoring, and stimulation. | Same |
| Contraindications | The Layer 7-T electrodearray should not be used onany patient whom thephysician/surgeon considersat risk for infection. TheLayer 7-T electrode array isnot intended for continuousstimulation. Stimulationshould only be applied tosupport the brain mappingpurpose of the array. | The subdural electrodesshould not be used on anypatient whom thephysician/surgeon considersat risk for infection. Thesubdural electrodes are notintended for continuousstimulation. Stimulationshould only be applied tosupport the brain mappingpurpose of the electrodes. | Same |
| Single patientuse, Disposable | Yes | Yes | Same |
| Provided Sterile | Yes | Yes | Same |
| Provided Non-Sterile (to besterilized by theuser) | No | No | Same.Electrodes areprovided sterile. Theyokes and yoke standare additional deviceaccessories for theLayer 7-T and areprovided non-sterile.They do not contact thepatient. |
| Environment ofUse | Operating Rooms andTemporary monitoring | Operating Rooms andTemporary monitoring | Same |
| Duration of Use | <30 days | <30 days | Same |
| Electrode BodySurface Area | $4.02cm^2$ | $\le 138cm^2$ | The smaller surfacearea does not impactsafety or effectiveness.Biocompatibility testingalong with GLP animaltesting demonstratesafety of the device.Bench testing over acomparable area alsodemonstrates that thefunctionality is thesame. |
| Feature | Layer 7-T (Subject Device) | Ad-Tech SubduralElectrodes (K191186) | Comment |
| ElectrodeContact Material | Platinum | Platinum/Iridium or StainlessSteel | This difference doesnot raise newquestions of safety andeffectiveness and thedevice performancedata support theelectrical stimulation isas safe and effectiveas the predicate. |
| MaximumStimulationCharge Density | $\leq$ 50µC/cm² | $\leq$ 30µC/cm² | Shannon Criteria (k <1.75) is more thansatisfied for the Layer7-T array.Microelectrodes andelectrodes in this sizerange (~0.1 mm² scale)have been shown toallow higher chargedensity limits as theygo away from Shannonconditions. However,the Layer 7-T stillstimulates at lowerintensities to ensuresafety across allparameters. |
| Number ofcontacts perelectrode | 1024 | Strips: 1-16Grids: 3-128 | Larger numbers ofelectrodes alone do notimpact device safety,as demonstrated bybiocompatibility testing,GLP animal testing,and electrical safetytesting. Functionality isverified by benchtesting anddemonstrated to beequivalent to thepredicate. |
| Feature | Layer 7-T (Subject Device) | Ad-Tech SubduralElectrodes (K191186) | Comment |
| StimulationFrequency | Not to exceed 50Hz | Not indicated in labeling | While the predicatedoes not specify thesevalues in their labeling,the addition of thesevalues to our labelingdoes not raise newquestions of safety andeffectiveness, and issupported byperformance testing. |
| Stimulation PulseTrains | Not to exceed 15 seconds | Not indicated in labeling | While the predicatedoes not specify thesevalues in their labeling,the addition of thesevalues to our labelingdoes not raise newquestions of safety andeffectiveness, and issupported by ourperformance testing. |
| Pulse train dutycycle | Not to exceed 50% | Not indicated in labeling | While the predicatedoes not specify thesevalues in their labeling,the addition of thesevalues to our labelingdoes not raise newquestions of safety andeffectiveness, and issupported by ourperformance testing. |
| Feature | Layer 7-T (Subject Device) | Ad-Tech Subdural Electrodes (K191186) | Comment |
| Contact Diameter | 0.05-0.5mm | 4.5mm | The range of contact diameters is changed to accommodate the higher density electrodes implied by a larger number of contacts per the same electrode surface area. Electrode to tail contact impedance is designed to meet applicable specification. Potential impacts of charge density are controlled by controlled charge density limits for the exposed electrode contact diameter (≤50 µC/cm2). |
| ElectrodeSpacing | 400μm | 10 mm | The electrode spacing is changed to accommodate the higher density implied by a larger number of contacts per the same electrode surface area. Electrode to tail contact impedance is designed to meet applicable specification. Potential impacts of charge density are controlled by controlled charge density limits for the exposed electrode contact diameter (≤50 µC/cm2). |
| Feature | Layer 7-T (Subject Device) | Ad-Tech SubduralElectrodes (K191186) | Comment |
| Electrode FilmMaterial | Polyimide | Silicone | The Layer 7-T hasundergone completebiocompatibility testingand GLP implantationtesting. All resultspassed.The polyimide materialis a known materialthat has been used inother FDA-clearedcortical arrays(NeuroOne K192764). |
| Sterilization | Ethylene Oxide | Ethylene Oxide | Same |
A table comparing the key features of the subject and predicate devices is provided below.
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Performance Data:
The Layer 7-T has undergone complete non-clinical testing to demonstrate that it is as safe and effective as the predicate which includes Sterilization, Packaging Validation, Shelf Life testing, Biocompatibility testing per ISO 10993-1, Electrical Safety and EMC testing, Performance testing for dimensional measurement, durability, electrochemical performance, platinum dissolution testing, Signal-to-Noise Ratio Testing, Reliability Testing, EEG system compatibility testing and human factors testing. The tests and their respective standards (if applicable) are listed below. All testing passed as expected.
| Test | Methods | Results |
|---|---|---|
| Dimensional Measurements | Confirm hardwarespecifications by measurementand visual assessment. | Pass |
| Durability | Mechanical testing, to verifythe electrode, lead bodies, andconnectors function safely andeffectively under normal useconditions. | Pass |
| Electrochemical Performance | Impedance testing conductedto verify conductiveproperties appropriate forthe device intended use.Testing verifies electricalcontinuity through theproposed device. | Pass |
| Platinum Dissolution Testing | Quantify the level of platinumreleased following astimulation protocolselected in a worst caseclinically relevant manner. | Pass |
| Signal-to-Noise Ratio Testing | Comparative Signal-to-NoiseRatio testing of Layer 7-T SNRto the predicate. | Pass |
| Reliability | Evaluate electrochemical andphysical properties followingaccelerated aging. | Pass |
| EEG system compatibility | Verification of signalacquired following cycling ofconnector. | Pass |
| Packaging Shelf Life | ASTM F2096-11(2019)Standard Test Methodfor Detecting GrossLeaks in Packaging byInternal Pressurization(Bubble Test)ASTM D4169-23 Standard | Pass |
| Sterilization | ISO 11135:2014Sterilization of health-care products –Ethylene oxide –Requirements for thedevelopment,validation and routinecontrol of a sterilization | Pass |
| process for medicaldevices | ||
| ASTM F1980-21 StandardGuide for AcceleratedAging of Sterile BarrierSystems and MedicalDevices |
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Biocompatibilitv
Layer 7-T is classified as blood contacting implant with prolonged contact during clinical use (< 24 hours to 30 days). The Layer 7-T was evaluated according to the FDA guidance (2023) "Use of International Standard ISO 10993-1, "Biological evaluation of medical devices - Part 1: Evaluation and testing within a risk management process". The following biocompatibility endpoints were assessed for the Layer 7-T:
- Cytoxicity ●
- Sensitization ●
- Irritation ●
- Acute Systemic Toxicity ●
- Material Mediated Pyrogenicity
- Genotoxicity
- Implantation Testing ●
- Hemolysis (Indirect Contact) ●
- Chemical characterization and a toxicological risk assessment was conducted to evaluate ● risks associated with subacute and subchronic toxicity.
Results support the biocompatibility of the Layer 7-T.
Electrical Safety and Electromagnetic Compatibility
The test reports address the basic safety evaluation (which includes electrical safety testing) per the FDA consensus standard IEC 60601-1:2005, IEC 60601-1:2005/AMD1:2012, IEC 60601-1:2005/AMD2:2020, and IEC 60601-1-6:2010, AMD1:2013, AMD2:2020. Additionally, EMC testing was conducted per IEC 60601-1-2:2014+A1:2020, EN 60601-1-2015+A1:2021, IEC 80601-2-49:2018, and IEC TR 60601-4-2:2024 and passed the applicable clauses. The results support the electrical safety and EMC of the device.
Human Factors
Usability has been validated to support the safety and effectiveness of their intended users and environment. This process was completed in accordance with the principles outlined in the "Applying Human Factors and Usability Engineering to Medical Devices" quidance. All evaluations have been performed according to ANSI AAMI HE75:2009 Human Factors Engineering – Design of Medical Devices
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Animal Testing
A Good Laboratory Practices (GLP) animal study was conducted to evaluate the Layer 7 cortical electrode array implanted into the subdural space of the brain. This study consisted of 16 female Göttingen swine divided into two cohorts, a 1-week implant duration and a 6-week implant duration. Neurological evaluation gross and microscopic analysis, were conducted, and the results from animals implanted with the Layer 7 cortical electrode array were compared to those from control animals implanted with the AD-TECH subdural strip electrodes. No adverse events were related specifically to the Layer 7 Cortical Electrode Array were identified in the study. The biocompatibility of the test article was confirmed based on the clinical status of the animals in the survival period and the results of the postmortem neuropathology examination. The pathology evaluation of this study revealed that both the test article and the control (predicate AD-TECH subdural strip electrodes) device had no evidence of ongoing neurotoxicity in the tested conditions, and elicited a similar cortical inflammatory response, which subsided in both groups by 6 weeks compared to the 1-week group.
The results from bench testing and animal studies demonstrate that the safety and performance of the Layer 7-T is similar to that of the predicate device, Ad-Tech Subdural Electrodes (K191186).
Conclusions
The subject Layer 7-T is as safe and effective as the predicate Ad-Tech Subdural Electrodes. The Layer 7-T has the same intended uses and similar indications for use, technological characteristics, and principles of operation as the predicate device. The minor differences in indications for use do not alter the intended use of the device and do not affect its safety and effectiveness when used as indicated. In addition, the technological differences between the Layer 7-T and its predicate device raise no new questions of safety or effectiveness. The performance data outlined above demonstrate that the Layer 7-T is as safe and effective as the Ad-Tech Subdural Electrodes. Thus, the Layer 7-T is substantially equivalent to the Ad-Tech Subdural Electrodes.
§ 882.1310 Cortical electrode.
(a)
Identification. A cortical electrode is an electrode which is temporarily placed on the surface of the brain for stimulating the brain or recording the brain's electrical activity.(b)
Classification. Class II (performance standards).