(446 days)
The DIXI Medical Intraoperative Subdural Electrodes (Strips and Grids) are intended for intraoperative use for less than or equal to 24 hours with recording and stimulation equipment for the recording and stimulation of electrical signals on the surface level of the brain. The recording of electrical activity supports brain mapping.
The DIXI Medical Intraoperative Subdural Electrode (Strips and Grids) is an intra-cranial electrode used intraoperatively on the surface of the brain. The device is designed for electroencephalography (EEG) recording and brief stimulation for brain mapping purposes. The DIXI Medical Intraoperative Subdural Electrode consists of circular contacts sandwiched between two layers of silicone substrate. The brain contacting side of the silicone substrate body has material removed to expose an amount of contact surface area. Insulated wires extend from each contact through a flexible tube which terminates in connectors for direct connection to user's equipment.
The device in question is the DIXI Medical Intraoperative Subdural Electrodes (Strips and Grids), which are intended for intraoperative use (less than or equal to 24 hours) for recording and stimulating electrical signals on the brain's surface to support brain mapping.
Here's an analysis of the acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance:
The document describes non-clinical and biocompatibility testing. The acceptance criteria are implicit in the "Objective" column for non-clinical tests and the "Conclusion" column for biocompatibility tests, which all show a "Pass" result indicating the device met the predefined safety and performance standards for each test.
| Test Performed | Objective / Reported Device Performance | Conclusion / Outcome |
|---|---|---|
| Nonclinical Testing | ||
| Dimensional Characteristics | Verification of electrodes dimensional characteristics | Pass |
| Electrical Characteristics | Verification of the electrodes ability to transmit a stimulation signal | Pass |
| Electrical Characteristics | Verification of the electrodes resistance to a stimulation signal under worst case charge density condition | Pass |
| Electrical Characteristics | Verification of the electrodes resistance to a stimulation signal under worst case current condition | Pass |
| Electrical Characteristics | Verification of the electrodes dielectric strength | Pass |
| Electrical Characteristics | Verification of electrodes stability under conditions of use (absence of corrosion) | Pass |
| Mechanical Characteristics | Verification of the resistance to torsion of the active part and silicon sheath | Pass |
| Mechanical Characteristics | Verification of electrodes resistance to bending | Pass |
| Mechanical Characteristics | Verification of electrodes resistance to traction | Pass |
| Biocompatibility Testing | ||
| Cytotoxicity | Percent viability of test article was 93.9%, 98.6%, and 88.5% of reagent control (across three tests). | Non-cytotoxic |
| Sensitization | Topical application of the 0.9% sodium chloride extract and the sesame oil extract did not induce delayed sensitization in the guinea pig. | Non-sensitizer |
| Intracutaneous Reactivity | Difference between each test extract overall mean score and corresponding control blank overall mean score was lower than 1.0 (0.0 for the 0.9% sodium chloride extract and sesame oil test extracts). | Non-irritant |
| Pyrogenicity | No rabbit showed an individual temperature rise higher or equal to 0.5℃ above its initial temperature. | Non-pyrogenic |
| Indirect (extract) Hemolysis | Mean hemolytic index for test article extract was of 0.0%. | Non-hemolytic |
| Acute Systemic Toxicity | No evidence of significant systemic toxicity or mortality after test article extracts injection. | Non-toxic |
2. Sample Sizes Used for the Test Set and Data Provenance:
- Test Set Sample Size: The document mentions that nonclinical testing was conducted on specific product references: C10-04CIOM, C10-08AIOM, and C10-16CIOM, C10-16AIOM for biocompatibility. However, it does not specify the exact number of units of each product that were tested for each individual test. It also refers to testing on "baseline and aged devices," with aged devices undergoing three sterilization cycles, accelerated aging (5 years), extreme climatic conditions, and transport tests, implying multiple units were used for aging studies.
- Data Provenance: The document does not explicitly state the country of origin of the data. It is a submission by DIXI Medical, located in France. The testing was conducted according to international standards (ASTM and ISO). The data is from nonclinical, pre-market testing, not patient-derived data (retrospective or prospective).
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications:
This information is not applicable. The studies described are non-clinical (device performance and biocompatibility) and do not involve expert-established ground truth in the context of clinical decision-making or diagnosis. The "truth" or acceptance criteria are based on established engineering and biological safety standards.
4. Adjudication Method for the Test Set:
This information is not applicable. Adjudication methods like 2+1 or 3+1 are typically used in clinical studies involving human readers or expert consensus on patient data. The current studies are bench tests and animal studies (for biocompatibility).
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This type of study is relevant for diagnostic or AI-assisted interpretation devices to compare human performance with and without AI. The DIXI Medical Intraoperative Subdural Electrodes are physical medical devices for electrical signal recording and stimulation, not for diagnostic image interpretation or AI-driven analysis.
6. Standalone Performance Study:
Yes, standalone (algorithm only without human-in-the-loop performance) studies were done for the device's physical and electrical characteristics and biocompatibility. The reported "Pass" results for all tests indicate the device met its predefined performance and safety criteria independently. The non-clinical and biocompatibility tests were conducted directly on the device itself or its materials.
7. Type of Ground Truth Used:
The "ground truth" for these tests refers to established engineering specifications, regulatory standards, and biological safety limits. For example:
- Nonclinical Testing: Ground truth is defined by the expected electrical (e.g., ability to transmit signal, resistance), dimensional, and mechanical properties of the device as per its design and intended use, validated against engineering standards.
- Biocompatibility Testing: Ground truth is based on the biological response limits defined by standards like ISO 10993, ensuring materials are non-cytotoxic, non-sensitizing, non-irritant, non-pyrogenic, non-hemolytic, and non-toxic.
8. Sample Size for the Training Set:
This information is not applicable. The device is a physical medical device, not an AI or machine learning algorithm that requires a "training set" in the conventional sense. The development of the device would have involved iterative design and testing, but not a formally defined "training set" for an algorithm.
9. How the Ground Truth for the Training Set Was Established:
This information is not applicable for the reasons stated in point 8.
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October 2, 2021
DIXI Medical % Cindy Domecus Principal Domecus Consulting Services LLC 1171 Barroilhet Drive Hillsborough. California 94010
Re: K201931
Trade/Device Name: DIXI Medical Intraoperative Subdural Electrodes (Strips and Grids) Regulation Number: 21 CFR 882.1310 Regulation Name: Cortical Electrode Regulatory Class: Class II Product Code: GYC Dated: September 1, 2021 Received: September 2, 2021
Dear Cindy Domecus:
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 (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 located 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.
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
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801); medical device reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 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 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 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 medical devices and radiation-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).
Sincerely,
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) K201931
Device Name
DIXI Medical Intraoperative Subdural Electrodes (Strips and Grids)
Indications for Use (Describe)
The DIXI Medical Intraoperative Subdural Electrodes (Strips and Grids) are intended for intraoperative use for less than or equal to 24 hours with recording and stimulation equipment for the recording and stimulation of electrical signals on the surface level of the brain. The recording of electrical activity supports brain mapping.
Type of Use (Select one or both, as applicable)
| ☑ Prescription Use (Part 21 CFR 201 Subpart D) |
|---|
| ☐ Over-The-Counter Use (21 CFR 201) |
| X Prescription Use (Part 21 CFR 801 Subpart D)
__ Over-The-Counter Use (21 CFR 801 Subpart C)
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510(k) Summary
I. SUBMITTER
510(k) Owner DIXI Medical 2A route de Poulignev 25640 Chaudefontaine, France Office: 033-3-81889890 Fax: 033-3-81889899 info@diximedical.com
Official Correspondent: Lucie Petegnief R&D Manager l.petegnief@diximedical.com
Submission Correspondent Cindy Domecus, R.A.C. (US & EU) Domecus Consulting Services LLC Phone: (650) 343-4813 Fax: (650) 343-7822 Email: Cindy@DomecusConsulting.com
Date Prepared September 24, 2021
II. DEVICE
Name of Device: DIXI Medical Intraoperative Subdural Electrodes (Strips and Grids) Common or Usual Name: Intraoperative Subdural Electrode Classification Name: 21 CFR §882.1310 Cortical Electrode Regulatory Class: II Product Code: GYC
III. PREDICATE DEVICE
The predicate device is the Ad-Tech Medical Instrument Corporation's Subdural Cortical Electrodes (K191186). There have been no recalls for the predicate device.
DEVICE DESCRIPTION IV.
The DIXI Medical Intraoperative Subdural Electrode (Strips and Grids) is an intra-cranial electrode used intraoperatively on the surface of the brain. The device is designed for
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electroencephalography (EEG) recording and brief stimulation for brain mapping purposes.
The DIXI Medical Intraoperative Subdural Electrode consists of circular contacts sandwiched between two layers of silicone substrate. The brain contacting side of the silicone substrate body has material removed to expose an amount of contact surface area. Insulated wires extend from each contact through a flexible tube which terminates in connectors for direct connection to user's equipment.
| ProductReference | Configuration | Schematic drawing |
|---|---|---|
| C10-08AIOM | 1 strip x 8contactsContactsnumbered from 1to 8 | Image: Schematic drawing of a connector with 1 strip of 8 contacts. |
| C10-16AIOM | 2 strip x 8contactsContactsnumbered from 1to 16 | Image: Schematic drawing of a connector with 2 strips of 8 contacts. |
| C10-06BIOM | 1 strip x 6contactsContactsnumbered from 1to 6 | Image: Schematic drawing of a connector with 1 strip of 6 contacts. |
| C10-12BIOM | 2 strip x 6contactsContactsnumbered from 1to 12 | Image: Schematic drawing of a connector with 2 strips of 6 contacts. |
| C10-04CIOM | 1 strip x 4contactsContactsnumbered from 1to 4 | Image: Schematic drawing of a connector with 1 strip of 4 contacts. |
A summary of the subject device configurations is provided below.
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| ProductReference | Configuration | Schematic drawing |
|---|---|---|
| C10-08CIOM | 2 strip x 4contactsContactsnumbered from 1to 8 | Image: Schematic drawing of C10-08CIOM |
| C10-16CIOM | 4 strip x 4contactsContactsnumbered from 1to 16 | Image: Schematic drawing of C10-16CIOM |
INDICATIONS FOR USE V.
The Indications for Use for the subject and predicate devices are noted below.
| DIXI Medical Intraoperative SubduralElectrodesSUBJECT DEVICE | AD-TECH Subdural Cortical ElectrodesPREDICATE DEVICE, K191186 |
|---|---|
| The DIXI Medical Intraoperative SubduralElectrodes (Strips and Grids) areintended for intraoperative use for lessthan or equal to 24 hours with recordingand stimulation equipment for therecording and stimulation of electricalsignals on the surface level of the brain.The recording of electrical activitysupports brain mapping. | The Ad-Tech Subdural Electrodes(Strip/Intraoperative Strip,Grid/Intraoperative Grid, Dual-SidedInterhemispheric, Multi-Strip and Split Grid,Intraoperative Mapping Grid) are intendedfor temporary (< 30 days) use withrecording, monitoring, and stimulationequipment for the recording, monitoring,and stimulation of electrical signals on thesurface of the brain. The recording ofelectrical activity supports definition of thelocation of epileptogenic foci and brainmapping. |
VI. COMPARISON OF TECHNOLOGICAL CHARACTERISTICS WITH THE PREDICATE DEVICE
The predicate device clearance is for a family of electrodes, whereas the subject device is for a single electrode type. As such, the below comparisons are between the subject device and the corresponding electrode type within the predicate device family of electrodes (i.e., the Intraoperative Strip and Intraoperative Grid).
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Both the subject and predicate devices are intended for use with recording and stimulation equipment for the recording and stimulation of electrical signals at the surface level of the brain. At a high level, the subject and predicate devices are based on the following same technological elements:
- Both the subject and predicate device are subdural cortical electrodes for the same . duration of use in the same environment of use.
- . Both the subject and predicate device are provided sterile and for single-use only and use the same method of sterilization.
- . Both the subject and predicate device have a maximum stimulation charge density of < 30 µC/cm².
- . The subject and predicate device have the same contact spacing, maximum number of contacts per electrode cable and diameter of electrode cable.
The following technological differences exist between the subject and the Intraoperative Strip and Intraoperative Grid predicate devices:
- The number of contacts per electrode is similar. The number of contacts for strips is . the same. The maximum number of contacts for predicate Intraoperative Grid is unknown but, in any case, the number of contacts for the subject device is within the range of the number of contacts for the predicate device.
- . The contact materials are similar but not identical; the subject device is stainless steel only, whereas the predicate device includes 90:10 Platimum:Iridium not present in the subject device.
- . The contact external diameter is similar but not identical; the subject device is 6.0mm-diameter only. The contact exposure diameter is similar but not identical. The subject device exposure diameter is within the range of exposure diameter for the predicate device.
- . Both the subject and predicate device cabling terminate in a 1.5mm female socket, but there is the option with the predicate device to connect to a patient cable.
VII. PERFORMANCE DATA
The following performance data were provided in support of the substantial equivalence determination.
Nonclinical Testing
The nonclinical testing included in the table below was conducted on subject devices, on baseline and aged devices. Aged devices underwent three sterilization cycles, accelerated aging equivalent to real-time ageing of 5 years (ASTM F1980), extreme climatic conditions (ASTM D4332) and tests of transport (ASTM D4169).
| TestPerformed | TestedDeviceReference | Objective | Conclusion |
|---|---|---|---|
| DimensionalCharacteristics | C10-04CIOMC10-08AIOM | Verification of electrodesdimensional characteristics | Pass |
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| TestPerformed | TestedDeviceReference | Objective | Conclusion |
|---|---|---|---|
| ElectricalCharacteristics | C10-04CIOMC10-08AIOM | Verification of the electrodes abilityto transmit a stimulation signal | Pass |
| Verification of the electrodesresistance to a stimulation signalunder worst case charge densitycondition | Pass | ||
| Verification of the electrodesresistance to a stimulation signalunder worst case current condition | Pass | ||
| Verification of the electrodesdielectric strength | Pass | ||
| Verification of electrodes stabilityunder conditions of use (absence ofcorrosion) | Pass | ||
| MechanicalCharacteristics | C10-04CIOMC10-08AIOM | Verification of the resistance totorsion of the active part and siliconsheath | Pass |
| Verification of electrodes resistanceto bending | Pass | ||
| Verification of electrodes resistanceto traction | Pass |
Biocompatibility Testing
The biocompatibility evaluation for the subject device was conducted in accordance with the FDA's September 2020 guidance Use of International Standard ISO 10993-1, "Biological evaluation of medical devices - Part 1: Evaluation and testing within a risk management process", Guidance for Industry and Food and Drug Administration Staff. The biocompatibility evaluation included the following tests and results:
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| Test | TestedDeviceReference | Result | Conclusion |
|---|---|---|---|
| Cytotoxicity | C10-08AIOM | Test 1: Percent viability of test articlewas 93.9% of reagent control.Test 1: Percent viability of test articlewas 98.6% of reagent control.Test 3: Percent viability of test articlewas 88.5% of reagent control. | Non-cytotoxic |
| Sensitization | C10-16CIOM | Topical application of the 0.9%sodium chloride extract and thesesame oil extract did not inducedelayed sensitization in the guineapig. | Non-sensitizer |
| Intracutaneousreactivity | C10-16CIOM | Difference between each test extractoverall mean score andcorresponding control blank overallmean score was lower than 1.0 (0.0for the 0.9% sodium chloride extractand sesame oil test extracts). | Non-irritant |
| Pyrogenicity | C10-16CIOM | No rabbit showed an individualtemperature rise higher or equal to0.5℃ above its initial temperature. | Non-pyrogenic |
| Indirect(extract)hemolysis | C10-16CIOM | Mean hemolytic index for test articleextract was of 0.0%. | Non-hemolytic |
| Acute SystemicToxicity | C10-16AIOM | No evidence of significant systemictoxicity or mortality after test articleextracts injection. | Non-toxic |
The contact classification for the subject device is an external communicating device with tissue/bone contact and cerebrospinal fluid (CSF) contact for a limited (≤24 hours) duration.
Sterilization and Shelf-Life Testing
The subject device is sterilized using Ethylene Oxide to a SAL = 10-6. A shelf-life of 5 years has been established based on accelerated and real-time aging.
CONCLUSIONS VIII.
The Indications for Use for the subject device is a subset of the Indications for Use for the predicate device, and the differences in technological characteristics do not raise new or different questions of safety and effectiveness, with the non-clinical and biocompatibility testing performed demonstrating the continued effectiveness of the subject device as compared to the predicate device.
§ 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).