(137 days)
Nexstim Navigated Brain Therapy (NBT®) System 2 is indicated for the treatment of Major Depressive Disorder in adult patients who have failed to achieve satisfactory improvement from prior antidepressant medication in the current episode.
The Nexstim NBT® System 2 is a repetitive transcranial magnetic stimulation (rTMS) system that delivers repetitive pulsed magnetic fields of sufficient magnitude to induce neural action potentials in the prefrontal cortex to treat the symptoms of major depressive disorder (MDD) without inducing seizure in patients who have failed one antidepressant medication.
The Nexstim NBT System 2 is used for patient treatment by prescription only and must be operated by a trained medical professional. It can be used in both inpatient and outpatient settings including physician's offices and clinics, psychiatric hospitals, and general medical/surgical hospitals with psychiatric units.
The Nexstim NBT System 2 consists of a group of devices designed to localize the stimulation site in the brain and deliver rTMS stimulation using controlling and interpretive software. Operational control of the Nexstim NBT System 2 is provided by the software.
The Nexstim NBT System 2 combines magnetic resonance imaging-based (MRI-based), three-dimensional (3-D) localization of cortical motor areas of the brain with non-invasive TMS and simultaneous electromyography (EMG) measurement to locate areas of the brain that are capable of evoking muscle responses when stimulated, and to locate the target area for depression therapy.
The Nexstim NBT System 2 software is used to import a patient's MR image slices through standard DICOM communication protocols, and generates an accurate 3-D model of the patient's head which can be "peeled back" to reveal the anatomical structures of the brain.
The provided text describes the Nexstim Navigated Brain Therapy (NBT) System 2, a repetitive transcranial magnetic stimulation (rTMS) system for treating Major Depressive Disorder. However, it does not contain specific acceptance criteria, reported device performance metrics in a table, or details of a study directly proving the device meets acceptance criteria in the format requested for AI/ML devices.
The document is a 510(k) summary, which focuses on demonstrating substantial equivalence to predicate devices rather than providing detailed clinical trial results or performance metrics against pre-defined acceptance criteria typical for novel AI/ML device evaluations.
It primarily details:
- Device Description and Intended Use
- Technology Comparison with predicate devices (showing similar technical characteristics)
- Summary of Performance Testing related to general medical device standards (sterilization, biocompatibility, software verification, electrical safety, EMC, and usability).
There are two studies mentioned under "Performance Testing – Bench Verification," which relate to the device's methods for determining motor threshold (MT) and coil localization, comparing them to manually-determined methods. However, these are not presented as a "study that proves the device meets the acceptance criteria" in the context of clinical effectiveness or diagnostic accuracy, which is often what is implied by "acceptance criteria" and "reported device performance" for AI/ML enabled devices.
Given the information provided, here's what can be extracted and what is missing:
Acceptance Criteria and Study Details (Based on provided text)
1. A table of acceptance criteria and the reported device performance
The document does not explicitly state acceptance criteria or device performance in the context of clinical efficacy or diagnostic accuracy in a table format. Instead, it refers to compliance with various medical device standards and internal specifications. The "Performance Testing - Bench Verification" section mentions two studies that compare specific aspects of the device's function (MT determination and coil localization) to other methods, suggesting "no significant statistical difference" or "substantially equivalent results" as outcomes for these functional aspects, which could be interpreted as meeting an implicit acceptance criterion of equivalence for these specific functions.
| Acceptance Criteria (Implied from Performance Testing) | Reported Device Performance |
|---|---|
| Biocompatibility: Device materials comply with ISO 10993-1. | Determined to be safe to use with patients. |
| Software: Complies with predetermined specifications and relevant FDA guidance (e.g., software development, cybersecurity), IEC 62304. | Software complies with its predetermined specifications, and the Standards and guidance documents. |
| Electrical Safety: Complies with IEC 60601-1, ANSI/AAMI ES 60601-1. | Nexstim NBT System 2 complies with the Standards. |
| Electromagnetic Compatibility (EMC): Complies with IEC 60601-1-2, FCC 47 CFR §15. | Nexstim NBT System 2 complies with the Standards. |
| Usability: Complies with IEC 60601-1-6, IEC 62366. | Nexstim NBT System 2 complies with the applicable Standards. |
| Motor Threshold (MT) Determination: Nexstim's Electromyography-Determined MT Method is comparable to Manually-Determined MT Method. (Study: O'Reardon, 2007; Pridmore, 1998) | Demonstrates no significant statistical difference between methods. |
| Navigated Coil Localization: Nexstim's method is comparable to Manually-Determined Method (moving the coil 5.5 cm anteriorly from the motor cortex). (Study: Ahdab, 2010) | Demonstrates substantially equivalent results between methods. |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
The document lists "Study Comparing Nexstim's Electromyography-Determined Motor Threshold (MT) Method to the Manually-Determined MT Method (O'Reardon, 2007; Pridmore, 1998)" and "Study Comparing Nexstim's Navigated Coil Localization Method to Manually-Determined Method (Ahdab, 2010)".
- Sample Size: Not specified in the provided text for either study.
- Data Provenance: Not specified in the provided text for either study (e.g., country of origin, retrospective or prospective). The studies are referenced by author and year, suggesting they are published literature or internal studies referring to published methods.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
Not specified in the provided text. For the MT and coil localization comparison studies, "manually-determined methods" serve as a reference, implying human expertise, but details are not given.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not specified in the provided text.
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. The Nexstim NBT System 2 is not an AI-assisted diagnostic device where "human readers" would be involved in interpreting data with or without AI. It is a therapeutic device (rTMS system). The listed comparative studies focus on functional aspects of the device (MT determination and coil localization) rather than comparative effectiveness studies in the context of improving human reader performance.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Not applicable in the typical sense of standalone AI performance. The device is a system operated by a trained medical professional. The functional comparisons (MT determination, coil localization) are aspects of the system's operation that are being compared to manual methods.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
- For the Motor Threshold (MT) determination, the ground truth appears to be established by a "manually-determined MT method" (implied expert determination, likely involving visual and/or manual assessment of muscle twitch).
- For the Navigated Coil Localization, the ground truth is a "manually-determined method (moving the coil 5.5 cm anteriorly from the motor cortex)," which is a standard anatomical targeting approach.
8. The sample size for the training set
Not applicable/specified. The document does not describe the device as an AI/ML system that undergoes "training." The software development process is mentioned, but without details on a training set for model development.
9. How the ground truth for the training set was established
Not applicable/specified, as there is no mention of an AI/ML "training set."
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November 10, 2017
Nexstim Plc Jarmo Laine Vice President, Medical Affairs Elimaenkatu 9b Helsinki, 00510 Finland
Re: K171902
Trade/Device Name: Nexstim Navigated Brain Therapy (NBT) System 2 Regulation Number: 21 CFR 882.5805 Regulation Name: Repetitive Transcranial Magnetic Stimulation System Regulatory Class: Class II Product Code: OBP, GWF, HAW, IKN Dated: October 11, 2017 Received: October 12, 2017
Dear Jarmo Laine:
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. 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 801); medical device reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820);
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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 http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.
For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/) and CDRH Learn (http://www.fda.gov/Training/CDRHLearn). 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 (http://www.fda.gov/DICE) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).
Sincerely,
William J. Heetderks -S 2017.11.10 09:28:53 -05'00'
Carlos L. Peña. PhD. MS for Director Division of Neurological and Physical Medicine Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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Indications for Use
510(k) Number (if known) K171902
Device Name
Nexstim Navigated Brain Therapy (NBT) System 2
Indications for Use (Describe)
Nexstim Navigated Brain Therapy (NBT) System 2 is indicated for the treatment of Major Depressive Disorder in adult patients who have failed to achieve satisfactory improvement from prior antidepressant medication in the current episode.
Type of Use (Select one or both, as applicable)
X Prescription Use (Part 21 CFR 801 Subpart D)
| Over-The-Counter Use (21 CFR 801 Subpart C)
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| Submission Date: | 01 October 2017 | ||
|---|---|---|---|
| Submitter: | Nexstim PlcElimaenkatu 9b00510 Helsinki, Finland | ||
| Submitter andOfficial Contact: | Mr. Jarmo LaineVice President, Medical AffairsNexstim PlcElimaenkatu 9b00510 Helsinki, Finland+011 358 50 374 2748jarmo.laine@nexstim.com | ||
| Manufacturing Site: | Nexstim PlcElimaenkatu 9b00510 Helsinki, Finland | ||
| Trade Name: | Nexstim Navigated Brain Therapy (NBT®) System 2 | ||
| Classification Name: | Repetitive Transcranial Magnetic Stimulator For Treatment Of MajorDepressive Disorder | ||
| PrimaryClassificationRegulation andProduct Code: | 21 CFR §882.5805 / OBP | ||
| SecondaryClassificationRegulation andProduct Code: | 21 CFR §882.1870 / GWF21 CFR §882.4560 / HAW21 CFR §890.1375 / IKN | ||
| SubstantiallyEquivalent Devices: | New Model | Predicate510(k) Number | PredicateManufacturer / Model |
| NexstimNavigatedBrain Therapy(NBT®)System 2 | K143531 | Magstim Company Limited / Rapid² TherapySystem (Primary Predicate) | |
| K112881 | Nexstim Oy / Nexstim Navigated BrainStimulation (NBS) System 4, Nexstim NBSSystem with NexSpeechTM (Reference Predicate) | ||
| K162935 | Magstim Company Limited / Rapid² TherapySystem (Reference Predicate) | ||
| K133408 | Neuronetics, Inc. Neurostar TMS TherapySystem (Reference Predicate) | ||
| K150641 | Tonica Elektronik A/S / MagVita TMS TherapySystem (Reference Predicate) |
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| Device Description: | The Nexstim NBT® System 2 is a repetitive transcranial magneticstimulation (rTMS) system that delivers repetitive pulsed magneticfields of sufficient magnitude to induce neural action potentials in theprefrontal cortex to treat the symptoms of major depressive disorder(MDD) without inducing seizure in patients who have failed oneantidepressant medication.The Nexstim NBT System 2 is used for patient treatment byprescription only and must be operated by a trained medicalprofessional. It can be used in both inpatient and outpatient settingsincluding physician's offices and clinics, psychiatric hospitals, andgeneral medical/surgical hospitals with psychiatric units.The Nexstim NBT System 2 consists of a group of devices designed tolocalize the stimulation site in the brain and deliver rTMS stimulationusing controlling and interpretive software. Operational control of theNexstim NBT System 2 is provided by the software.The Nexstim NBT System 2 combines magnetic resonance imaging-based (MRI-based), three-dimensional (3-D) localization of corticalmotor areas of the brain with non-invasive TMS and simultaneouselectromyography (EMG) measurement to locate areas of the brain thatare capable of evoking muscle responses when stimulated, and tolocate the target area for depression therapy.The Nexstim NBT System 2 software is used to import a patient's MRimage slices through standard DICOM communication protocols, andgenerates an accurate 3-D model of the patient's head which can be"peeled back" to reveal the anatomical structures of the brain. |
|---|---|
| Intended Use: | Nexstim Navigated Brain Therapy (NBT®) System 2 is indicated forthe treatment of Major Depressive Disorder in adult patients who havefailed to achieve satisfactory improvement from prior antidepressantmedication in the current episode. |
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Technology Comparison:
The Nexstim NBT System 2 employs the same technological characteristics as the predicate devices.
| Characteristic | MagstimCompanyLimited Rapid²Therapy System(K143531)(PrimaryPredicate) | Nexstim Oy NBS System 4with NEXSPEECH™(K112881)(Reference Predicate) | Nexstim NavigatedBrain Therapy(NBT®) System 2(Proposed Device) |
|---|---|---|---|
| Magnetic FieldIntensity | 120 % of motorthreshold (MT) | Not applicable | 120 % of MT |
| Frequency | 10 Hz | Not applicable | 10 Hz |
| Train Duration | 4 seconds (sec) | Not applicable | 4 sec |
| Inter-trainInterval | 26 sec | Not applicable | 26 sec |
| Number oftrains | 75 | Not applicable | 75 |
| Maximumpulses persession | 3,000 | Not applicable | 3,000 |
| Treatmentsession duration | ~ 37.5 minutes | Not applicable | ~ 37.5 minutes |
| Sessions/week | Five (5) | Not applicable | Five (5) |
| Treatmentschedule | Five (5) dailysessions for six(6) weeks | Not applicable | Five (5) dailysessions for six (6)weeks |
| Area of brain tobe stimulated | DorsolateralPrefrontal cortex(DLPFC) | Language areas | DLPFC |
| Coil Material | Copper windingwith air core | Copper winding with air core | Copper windingwith air core |
| Coil Windings | 70 mmN = 3 x 19 turns/wing x 2 wings(1.75 mm x 6mm) | 72 mm (coilwing distance 2 mm, coil windcenter distance 74 mm)10 turns/wing | 72 mm (coilwing distance 2mm, coil windcenter distance 74mm)10 turns/wing |
| AverageInductance | 12 μH | 10.4 μH | 10.4 μH |
| Characteristic(continued) | MagstimCompanyLimited Rapid²Therapy System(K143531)(PrimaryPredicate) | Nexstim Oy NBS System 4with NEXSPEECH™(K112881)(Reference Predicate) | Nexstim NavigatedBrain Therapy(NBT®) System 2(Proposed Device) |
| AmplitudeRange | 0.28 to 1.9Standard MT(SMT) | 0 to 2.5 SMT | 0 to 2.5 SMT |
| Pulse Length | 300 µsec | 230 µs ± 5 µsec | 230 µs ± 5 µsec |
| FrequencyRange | 0.1 - 30 Hz | 0.1 - 50 Hz | 0.1 - 50 Hz |
| CoilPositioningPrinciple | Indirecttargeting oftreatment targetthoughmeasureddistance anddirection (5cm)from AbductorPollicis Brevis(APB).Measure derivedfrom statisticaldistance ofDLPFC fromAPB. | Individual patient directtargeting of anatomicaltreatment location (Languageareas).Placing of E-field maximumlocation on 3D model builtfrom patients individual MRI. | Individual patientdirect targeting ofanatomicaltreatment location(DLPFC).Placing of E-fieldmaximum locationon 3D model builtfrom patientsindividual MRI. |
| MT ResponseDetection | Visualqualitativemonitoring forAPB response. | EMG provides qualitative andquantitative data based onwhich user defines MT. | EMG providesqualitative andquantitative databased on which userdefines MT. |
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Summary of Performance Testing:
| Sterilization andShelf LifeVerification | The Nexstim NBT System 2 is not shipped sterile, and is not intended to be sterilized by the user. |
|---|---|
| The NBT Head Tracker has a shelf life of 2 years. | |
| The Nexstim Focal and Cooled Coils have a useful product life of two (2) million pulses or two (2) years from date of manufacture, whichever comes first. | |
| No other Nexstim NBT System 2 component has a shelf life. | |
| BiocompatibilityVerification | Patient contact materials which are part of the Nexstim NBT System 2were designed to comply with the following standard:• ISO 10993-1: 2009, Biological evaluation of medical devices –Part 1: Evaluation and testing within a risk management process,and were determined to be safe to use with patients. |
| Software Verificationand Validation | Software for the Nexstim NBT System 2 was designed and developedaccording to a robust software development process, and wererigorously verified and validated.Software information is provided in accordance with internaldocumentation and the following Standards and guidance documents:• FDA guidance: The content of premarket submissions for softwarecontained in medical devices, 11 May 05;• FDA guidance: Off-the-shelf software use in medical devices, 09Sep 99;• FDA guidance: General principles of software validation; Finalguidance for industry and FDA staff, 11 Jan 02;• FDA guidance: Content of premarket submissions for managementof cybersecurity in medical devices, 02 Oct 14.• FDA guidance: Cybersecurity for Networked Medical DevicesContaining Off-The-Shelf (OTS) software, 14 Jan 05; and• IEC 62304: 2006, Medical device software – Software life cycleprocesses.Test results indicate that the Nexstim NBT System 2 software complieswith its predetermined specifications, and the Standards and guidancedocuments. |
| Electrical SafetyVerification | The Nexstim NBT System 2 was tested for performance in accordancewith the following Standards:• IEC 60601-1: 2005, Am1: 2012, Medical electrical equipment -Part 1: General requirements for basic safety and essentialperformance; and• ANSI/AAMI ES 60601-1: 2005, Am2: 2010, US Nationaldifferences to IEC 60601-1: 2005.Test results indicated that the Nexstim NBT System 2 complies withthe Standards. |
| ElectromagneticCompatibility (EMC)Verification | The Nexstim NBT System 2 was tested for performance in accordancewith the following Standard: |
| IEC 60601-1-2: 2007, Medical electrical equipment – Part 1-2:●General requirements for basic safety and essential performance –Collateral standard: Electromagnetic compatibility – Requirementsand tests; and | |
| FCC 47 CFR §15, Telecommunication Chapter I--Federal●Communications Commission Subchapter A-General- RadioFrequency Devices | |
| Test results indicated that the Nexstim NBT System 2 complies withthe Standards. | |
| Performance Testing– Bench Verification | The Nexstim NBT System 2 was tested for performance in accordancewith internal documentation and the following FDA GuidanceDocuments and Standards: |
| Guidance for Industry and Food and Drug Administration Staff●Class II Special Controls Guidance Document: RepetitiveTranscranial Magnetic Stimulation (rTMS) Systems | |
| Study Comparing Nexstim's Electromyography-Determined Motor●Threshold (MT) Method to the Manually-Determined MT Method(O'Reardon, 2007; Pridmore, 1998) Demonstrating No SignificantStatistical Difference Between Methods | |
| Study Comparing Nexstim's Navigated Coil Localization Method to●Manually-Determined Method (moving the coil 5.5 cm anteriorlyfrom the motor cortex, Ahdab, 2010) Demonstrating SubstantiallyEquivalent Results Between Methods | |
| Test results indicated that the Nexstim NBT System 2 complies with itspredetermined specification and the applicable Standard. | |
| Performance Testing– UsabilitvValidation | The Nexstim NBT System 2 was tested for usability in accordancewith the following Standards: |
| IEC 60601-1-6: 2010, Medical electrical equipment – Part 1-6:●General requirements for basic safety and essential performance –Collateral standard: Usability; and | |
| IEC 62366: 2007, Medical devices – Application of usability●engineering to medical devices. | |
| Test results indicated that the Nexstim NBT System 2 complies withthe applicable Standards. |
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Conclusion Verification and validation activities were conducted to establish the performance and safety characteristics of the Nexstim NBT System 2. The results of these activities demonstrate that the Nexstim NBT System 2 is safe and effective when used in accordance with its intended use and labeling.
Therefore, the Nexstim NBT System 2 is considered substantially equivalent to the predicate devices.
§ 882.5805 Repetitive transcranial magnetic stimulation system.
(a)
Identification. A repetitive transcranial magnetic stimulation system is an external device that delivers transcranial repetitive pulsed magnetic fields of sufficient magnitude to induce neural action potentials in the prefrontal cortex to treat the symptoms of major depressive disorder without inducing seizure in patients who have failed at least one antidepressant medication and are currently not on any antidepressant therapy.(b)
Classification. Class II (special controls). The special control is FDA's “Class II Special Controls Guidance Document: Repetitive Transcranial Magnetic Stimulation System.” See § 882.1(e) for the availability of this guidance document.