(147 days)
Not Found
The Cortac Cortical Electrode is used intraoperatively for monitoring recordable electrical brain activity or Electroencephalography (EEG) when less invasive methods do not provide the electrophysiology data necessary. This invasive intracranial, subdural electrode recording is performed directly on the surgically exposed brain. This method is necessary when the seizure focus is to small and or to deep within the brain to produce a recordable EEG seizure. The Cortac Cortical Subdural strip and grid electrode are used in cases where it's necessary to establish a high degree of confidence in the electrical localization (Foci), seizure frequency, severity type and other electroclincal characteristics.
This 510(k) premarket notification describes a medical device called the "PMT Cortac Cortical Electrode," and primarily focuses on demonstrating its substantial equivalence to existing devices, rather than presenting a study proving performance against specific acceptance criteria for a novel AI or diagnostic algorithm.
Therefore, many of the requested categories for AI/diagnostic device studies (like sample size for test set, ground truth experts, MRMC studies, standalone performance, training sets, etc.) are not applicable to this document. This document is a regulatory submission for a physical medical electrode, not a software algorithm.
However, I can extract information related to what might be considered "acceptance criteria" for a physical device, and any "studies" mentioned, even if they are fundamentally different from those associated with AI.
Here's the information extracted and organized to the best of what the document provides:
1. Table of Acceptance Criteria and Reported Device Performance
Since this is a physical medical device, the "acceptance criteria" are related to its physical and functional specifications, sterilization, biocompatibility, and pyrogenicity. The "performance" is reported as meeting these specifications.
| Acceptance Criteria Category | Specific Criteria/Test | Reported Device Performance |
|---|---|---|
| Material Properties | Pliability | Conform to brain topography without buckling/compression |
| Electrode Design | Contact with brain tissue | Maximizes contact, minimizes pockets for air/CSF |
| Electrical Continuity | Weld between contact/wire | Good electrical continuity with minimal resistance |
| Mechanical Strength | Weld tensile strength | Comparable to wire |
| Sterilization | Sterilization Method | 100% Ethylene Oxide (overkill method) |
| Sterility Assurance Level (SAL) | 10⁻⁶ probability of a nonsterile unit (validated) | |
| Pyrogenicity | Pyrogen Limit | 2.4 Eu/device (determined by Limulus Amebocyte Lysate Test) |
| Test Standard | USP Endotoxin Reference Standard | |
| Biocompatibility | Compatibility Class | Implant device, contacting tissue/bone, "A" class duration (< 24 hours) |
| Tests Passed | Cytotoxicity, Sensitization, Irritation, Systemic Toxicity | |
| Packaging | Pouch pull apart strength | 1-3 lb. (Tyvek with chevron design) |
2. Sample Size Used for the Test Set and Data Provenance
- Not applicable for an AI/diagnostic algorithm. This document describes a physical medical device. The "tests" mentioned (biocompatibility, pyrogenicity, sterilization validation) would involve laboratory samples of the device itself and biological testing, not a dataset of patient information.
- Data Provenance: Not applicable in the context of clinical data for an algorithm. The tests are performed on the manufactured device.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Not applicable. This document does not describe a diagnostic algorithm requiring ground truth established by medical experts for a test set. The "ground truth" for the device's physical and biological properties is established through standardized laboratory testing protocols (e.g., USP standards for pyrogenicity, ISO standards for biocompatibility).
4. Adjudication Method for the Test Set
- Not applicable. This relates to expert consensus for diagnostic interpretation, which is not relevant for this physical device's regulatory submission.
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
- Not applicable. This refers to studies for AI-assisted diagnostic tools. The PMT Cortac Cortical Electrode is a physical tool for recording brain activity, not an AI.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- Not applicable. This refers to the performance of an AI algorithm independently.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)
- For physical device properties: The "ground truth" is defined by established scientific and regulatory standards (e.g., ISO standards for biocompatibility, USP standards for endotoxins, validated sterilization cycle parameters) rather than expert medical consensus on patient data.
- Biocompatibility: In vitro (cytotoxicity) and in vivo (sensitization, irritation, systemic toxicity) animal models following specific protocols.
- Pyrogenicity: Chemical assay (Limulus Amebocyte Lysate Test) against a known standard.
- Sterility Assurance Level: Microbiological challenge and validation studies for the sterilization process.
8. The Sample Size for the Training Set
- Not applicable. This refers to machine learning models.
9. How the Ground Truth for the Training Set Was Established
- Not applicable. This refers to machine learning models.
Summary of "Studies" mentioned in the 510(k):
The document references several conformity assessments and validation processes, which can be interpreted as "studies" in the context of device approval:
- Sterilization Validation: "The type of sterilization is 100% Ethylene Oxide. The sterilization method employed is the overkill method and validated to the terminal process endpoint probability of a nonsterile unit of 10⁻⁶." This implies a microbiology validation study was performed.
- Pyrogenicity Determination: "The method of determination is the Limulus Amebocyte Lysate Test. The Bacterial Endotoxin test is conducted as described in the USP Endotoxin Reference Standard." This indicates laboratory testing was performed according to Pharmacopeia standards.
- Biocompatibility Testing: "The PMT Cortac Cortical Electrode is tested for biocompatibility per the General Program Memo # G95-1, the device is classified as an implant device, contacting tissue/ bone with an "A" class duration of contact (< 24 hours). The Cortac Cortical Electrode passed the tests for Cytotoxicity, Sensitization, Irritation and Systemic toxicity." This refers to specific biological safety tests performed according to regulatory guidance.
- Substantial Equivalence Comparison: The entire 510(k) is a "study" in the sense that it compares the new device to legally marketed predicate devices (Ojemann Cortical Stimulator, Wyler Subdural Strip Electrode, and PMT 2111-4 stainless steel Cortac Cortical electrode) to demonstrate it is "at least as safe and effective" and shares features like intended use, technology, and performance specifications. This is the primary "proof" within a 510(k).
{0}------------------------------------------------
K9 64 224
MAR 1 9 1997
Premarket Notification [510(k)] Summary
Submitters name: PMT CORPORATION
Submitters Address: 1500 Park Road Chanhassen, MN 55317
Phone: (612) 470-0866
Fax: (612) 470-0865
Contact name: Edward F. Valdez
Date: 9/30/96
Trade name: PMT Cortac Cortical Electrode
Common name: Cortical Electrode
Classification name: Electrode, Cortical (per 21 CFR section 882.1310)
Equivalent device(s):
The Ojemann Cortical Stimulator(OCS -1), manufactured by Radionics, Inc. The Wyler Subdural Strip Electrode, manufactured by ADTEC and the PMT 2111-4 stainless steel Cortac Cortical electrode has met the criteria for substantial equivalence to the series of PMT Cortac cortical electrodes.
Device Description:
The Cortac Cortical Electrode is used intraoperatively for monitoring recordable electrical brain activity or Electroencephalography (EEG) when less invasive methods do not provide the electrophysiology data necessary. This invasive intracranial, subdural electrode recording is performed directly on the surgically exposed brain. This method is necessary when the seizure focus is to small and or to deep within the brain to produce a recordable EEG seizure. The Cortac Cortical Subdural strip and grid electrode are used in cases where it's necessary to establish a high degree of confidence in the electrical localization (Foci), seizure frequency, severity type and other electroclincal characteristics.
{1}------------------------------------------------
The Cortac Cortical Electrode Subdural strips and subdural electrode grids are inserted subdura onto the gray matter of the brain through a skin incision and bone flap (Craniotomy). The number of electrode contacts required in the subdural strios and grid increases for wide spread coverage. PMT offers cortical electrodes with 1 upto 64 electrodes.
Once on the brain the subdural strips and subdural electrode grids must be pliable so that it lies over the features of the brain, such as specific gyral convolutions, lesions and brain anatomical topography. The strips or grids envelop the electrodes, except for the exposed electrode contact. The strips and grids are manufactured with a biocompatible silicone with a thickness and durameter enabling pliability of the strip or grid to conform to the brain and its anatomical topography without the hazard of buckling and compression of the cortical veins and the cortex.
The electrodes are either stainless steel or platinum metal. The stainless steel and platinum electrode contact and wiring system are preferred for the electroconductivity and biocompatibility with minimal resistance to electrolysis. The electrophysiologist may prefer one material choice over another knowing the electrical resistance of the stainless steel is higher than that of platinum.
The electrode contacts are die and punch cut by design into a top hat shape . The top hat shape allows the reading portion of the electrode contact surface approximately level with the silicone strip and grid while allowing sufficient embedded electrode contact area to maintain integrity of the structure. The benefit of the design allows for maximum contact with the brain tissue thus minimizing pockets or space available for insulating barriers such as, air or cerebrospinal fluid (CSF). The electrode contacts are available in three sizes to accommodate the variety of patients and electrophysiologist preference.
The electrode contacts are attached to the conducting wire (same material type) with a weld. The wire is insulated to prevent wire from shorting with other wires in the assembly. The weld provides good electrical continuity with minimal electrical resistance across the contact to wire transition, while providing a tensile strength comparable to that of the wire.
A variety of wiring patterns are available to minimize wire to wire contact for the different number of electrode contacts.
The wires converge into silicone tubing conduit that provides the mechanical structure between the Inplanted strip or grid and the connector assembly (external). The silicone tubing is sealed into the proximal end of the strip or grid. A maximum of 10 wires are in each lumen of the bilumen tube. The 64 contact electrode will have no more than 4 standard bilumen tubes attached.
{2}------------------------------------------------
The silicone tubing conduit terminates in a connector. The connector attaches the silicone tubing and wire. The wire and connector contacts are press fit. Silicone adhesive is used to attach the silicone tubing to the connector.
Several types of connectors are available. As the number of electrode contacts increase, the tube conduit may become so bulky that skin incisions and passage through the subcutaneous tissue becomes necessary to minimize concerns about potential cerebrospinal fluid (CSF) leakage and infection of the subdural space. The mini-connector has a 6 mm diameter and can be brought out through the skin using guiding needle punctures. Larger connectors are available.
The connector connects to the interconnect cable external of the patient. The interconnect cable attaches to the EEG equipment. The connector contacts are brass female connector pins.
The PMT Cortac Cortical Electrode is provided in a primary and secondary pouch. The pouch is a tyvek and cellophane configuration. The tyvek pouch with the chevron design feature provides a 1- 3 lb. pull apart strength.
The PMT Cortac Cortical Electrode is provided sterile or nonsterile. The type of sterilization is 100% Ethylene Oxide. The sterilization method employed is the overkill method and validated to the terminal process endpoint probability of a nonsterile unit of 10-6.
The PMT Cortac Cortical Electrode is provided pyrogen free. The method of determination is the Limulus Amebocyte Lysate Test. The Bacterial Endotoxin test is conducted as described in the USP Endotoxin Reference Standard. The pyrogen limit for the Cortac Cortical Electrode is 2.4 Eu/device.
The PMT Cortac Cortical Electrode is tested for biocompatibility per the General Program Memo # G95-1, the device is classified as an implant device, contacting tissue/ bone with an "A" class duration of contact (< 24 hours). The Cortac Cortical Electrode passed the tests for Cytotoxicity, Sensitization, Irritation and Systemic toxicity.
§ 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).