(181 days)
The NVM5® System is a medical device that is intended for intraoperative neurophysiologic monitoring during spinal surgery. The device provides information directly to the surgeon, to help assess a patient's neurophysiologic status. NVM5 provides this information by electrically stimulating nerves via electrodes located on surgical accessories and monitoring electromyography (EMG), transcranial motor evoked potential (TceMEP) or somatosensory evoked potential (SSEP) responses of nerves. The System also integrates Bendini™ software used to locate spinal implant instrumentation for the placement of spinal rods.
- XLIF® (Detection) -- The XLIF (Detection) function allows the surgeon to locate and evaluate spinal nerves, and is used as a nerve avoidance tool.
- Basic & Dynamic Screw Test The Screw Test functions allow the surgeon to locate and evaluate spinal nerves by providing proximity information before. during or after bone preparation and placement of bone screws.
- Free Run EMG -- The Free Run EMG function identifies spontaneous EMG activity of spinal nerves by continually displayinq a live stream waveform of any mechanically induced myotome contractions.
- Twitch Test (Train of Four) ~ The Twitch Test Function allows the surgeon to assess moderate degrees of neuromuscular block in effect by evaluating muscle contraction following a train of four stimulation pulses.
- TcMEP - Transcranial stimulation techniques for motor evoked potentials are used to assess for acute dysfunction in axonal conduction of the corticospinal tract. The TcMEP function provides an adjunctive method to allow the surgeon to monitor spinal cord and motor pathway integrity during procedures with a risk of surgically induced motor injury.
- SSEP - The SSEP function allows the surgeon to assess sensory spinal cord function in surgical procedures during which the spinal cord is at risk.
- Remote Reader The Remote Reader function provides real time remote access to the NVM5 System for a monitoring physician outside of the operating room.
- Guidance The Guidance function is intended as an aid for use in either open or percutaneous pedicle cannulation procedures in the lumbar and sacral spine (L 1-S1) of adult patients, and when used in conjunction with radiographic imaging and EMG, allows the surgeon to assess the anqulation of system accessories relative to patient spinal anatomy for the creation of a cannulation trajectory for bone screw placement.
- Bendini - The Bendini Spinal Rod Bending function is used to locate spinal implant system instrumentation (screws, hooks) to determine their relative location to one another to generate bend instructions to shape a spinal rod. A surgeon is able to use those instructions and bend a rod using the Bendini Bender, a mechanical rod bender.
NVM5 System is a medical device that is intended for intraoperative neurophysiologic monitoring during spinal surgery. The device provides information directly to the surgeon, to help assess a patient's neurophysiologic status. NVM5 provides this information by electrically stimulating nerves via electrodes located on surgical accessories and monitoring electromyography (EMG), transcranial motor evoked potential (TcMEP) or somatosensory evoked potential (SSEP) responses of nerves. Moreover, a Twitch Test ("Train of Four") function is utilized to test the ability of the nerve to respond, or contract, following four stimulation pulses to determine the presence of neuromuscular block. Additionally, the NVM5 System includes an integrated stereotactic guidance system (NVM5 Guidance) to support the delivery of pedicle screws during EMG monitoring. The System also integrates Bendini™ software used to locate spinal implant instrumentation for the placement of spinal rods. Lastly, the system also offers an optional screen sharing application (Remote Monitoring) to allow a secondary physician to remotely view the events represented on the NVM5 user interface. In summary, the NVM5 System includes the following six (6) software functionalities / modalities:
- Electromyography (EMG)
- Transcranial Motor Evoked Potential (TceMEP), or simply MEP
- Somatosensory Evoked Potential (SSEP)
- Guidance
- Bendini
- Remote Monitoring
The NVM5 System hardware consists of a Patient Module (PM) and computer, as well as accompanying accessory components which consist of an assortment of disposable conductive probes, electrodes, and electrode leads.
The NuVasive® NVM5® System is intended for intraoperative neurophysiologic monitoring during spinal surgery. The system provides information to the surgeon to assess a patient's neurophysiologic status by electrically stimulating nerves and monitoring electromyography (EMG), transcranial motor evoked potential (TceMEP), or somatosensory evoked potential (SSEP) responses. It also includes Bendini™ software for locating spinal implant instrumentation for rod placement.
The FDA 510(k) submission (K123307) dated March 15, 2013, concludes that the NuVasive® NVM5® System is substantially equivalent to legally marketed predicate devices based on indications for use, technological characteristics, and performance testing.
Here's the breakdown of the acceptance criteria and the study that demonstrates the device meets these criteria:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria provided in the document are primarily based on demonstrating substantial equivalence to predicate devices across various technical specifications and functionalities. The reported device performance is presented as a comparison between the subject NVM5 System and its predicate devices, where "YES" indicates substantial equivalence.
Note: The document does not provide specific quantitative acceptance criteria or numerical performance metrics for each function (e.g., a specific accuracy percentage for nerve detection as an absolute requirement set beforehand). Instead, it relies on demonstrating that the performance of the NVM5 System is comparable to or better than previously cleared predicate devices through verification and validation testing, and compliance with recognized standards.
| Specification/Property | Acceptance Criteria (Predicate Performance or Standard Compliance) | Reported Device Performance (Subject NVM5 System) | Meets Criteria? (Substantial Equivalence Claimed) |
|---|---|---|---|
| Intended Use / Indications | For intraoperative neurophysiologic monitoring during spinal surgery, providing information to assess neurophysiologic status by stimulating nerves and monitoring EMG, TceMEP, or SSEP responses. Predicate NVM5 also includes: XLIF (Detection), Basic & Dynamic Screw Test, Free Run EMG, Twitch Test (Train of Four), TcMEP, SSEP, Remote Reader, Guidance (lumbar spine). Predicate Bendini (K122742) for locating spinal implant instrumentation and generating rod bend instructions. | The NVM5 System's intended use matches the predicate NVM5. The Guidance indications were expanded to include the S1 level of the spine. The Bendini function is integrated, with indications identical to those cleared in predicate K122742. | YES |
| Software Functionalities | XLIF Detection, Basic & Dynamic Screw Test, Free Run EMG, Twitch Test (Train of Four), TceMEP, SSEP, Remote Monitoring, Guidance (from predicate K112718). Bendini function (from predicate K122742). | All predicate functionalities are present. Additionally, Bendini function is incorporated into the NVM5 System. | Yes |
| Algorithms | Identical algorithms to predicate (K112718) for XLIF Detection, Basic & Dynamic Screw Test, Free Run EMG, Twitch Test (Train of Four), TceMEP, SSEP, Guidance. Bendini algorithm (from predicate K122742). Other SSEP auto algorithms. | Identical algorithms as predicate, with additional algorithms for SSEP Auto and Bendini functions. Bendini algorithm is substantially equivalent to predicate 510(k) K122742. | Yes |
| Total Available Channels | 32 (from predicate K112718) | 32 | Yes |
| Headbox/Patient Module | IEC 60601-1 Compliant (from predicate K112718) | Yes (Compliant) | Yes |
| Full Scale View Range | ±0.5 μV to ±8mV (from predicate K112718) | ±0.5 μV to ±8mV | Yes |
| Frequency Response | 3 Hz to 4.8 kHz (from predicate K112718) | 3 Hz to 4.8 kHz | Yes |
| User Interface | Control Unit: Touch screen and [optional] keyboard/mouse (from predicate K112718) | NuVasive-supplied computer with optional touch screen and/or keyboard/mouse. | Yes |
| Remote Monitoring | Yes (from predicate K112718) | Yes | Yes |
| Train of Four Testing | Yes (from predicate K112718) | Yes | Yes |
| Guidance - Angular Tolerance | Predicate systems (Medtronic StealthStation, BrainLAB VectorVision Trauma) had 6 DOF (positional and rotational in x, y, z). The predicate NVM5 Guidance (K112718) only displayed instrument orientation (rotational in x, y planes) with respect to gravity. | Angular tolerance of ±2°. The subject device's Guidance is designed for 2 DOF (rx, ry) data. This is deemed substantially equivalent because it is used with fluoroscopic imaging and not indicated for use by the predicate StealthStation. The amount of data collected is sufficient to provide angular outputs for comparison with planned trajectory when radiographic imaging confirms starting point and trajectory. | Yes |
| Guidance - Clinical Use | Requires input from CT, MRI, or radiographic images. Assists surgeon in cannulating pedicle based on user predefined trajectory. Integrate with EMG stimulation. (Matched by predicate NVM5 Guidance K112718). | Matches predicate. | Yes |
| Bendini - System Design | Optical (IR) tracking technology system, IR tracking instruments, control unit, mobile stand. User interface: touch screen, GUI, audio. (from predicate K122742). | Optical (IR) tracking technology system, IR tracking instruments, computer. User Interface: Touch screen, graphical user interface and audio. Conformance with Recognized Standards: IEC 60601-1, IEC 60601-1-2. Power Supply - Line Input. | Yes |
| Bendini - Instrumentation | IR Stylus (with integrated passive spheres), Rod Bender (from predicate K122742). | IR Stylus (with integrated passive spheres), Rod Bender. | Yes |
| Safety and Standards | Compliance with IEC 60601-1, IEC 60601-1-2, IEC 60601-2-40. Tracking instruments composed of known and accepted (biocompatible) materials. Sterilization validated to assure SAL of 10-6. | The NVM5 System was subjected to verification and validation testing, as well as electrical safety/compatibility testing, including compliance with IEC 60601-1, IEC 60601-2-40, and IEC 60601-1-2. Tracking instruments used known, biocompatible materials. Sterilization for accessories as selected and validated to SAL of 10-6. | Yes (All listed standards met) |
| Guidance Performance | Clinical literature data from predicate devices (BrainLAB VectorVision Trauma and Medtronic StealthStation for lumbosacral levels) demonstrating accuracy for percutaneous lumbar pedicle screw placement and thoracolumbar pedicle screw placement using 3D image guidance. | Guidance performance data comparison from literature data from clinical literature demonstrates substantial equivalence. (References two specific studies: "Accuracy of percutaneous lumbar pedicle screw placement using the oblique or 'owl's-eye' view and novel guidance technology" (J Neurosurg Spine, 2010) and "Placement of thoracolumbar pedicle screws using three-dimensional image guidance: experience in a large patient cohort" (J Neurosurg Spine, 2009)). | Yes |
| Bendini Performance | Predetermined specifications outlined in the SRS for GUI functionality, error handling, system accuracy during data acquisition, verification of instrument performance in combination with the software, and verification of software algorithms. | Nonclinical testing included evaluation of software performance per predetermined specifications, GUI functionality, error handling, system accuracy during data acquisition, verification of instrument performance with software, and verification of software algorithms. | Yes |
2. Sample Size Used for the Test Set and Data Provenance
The document primarily refers to "nonclinical testing" and "verification and validation testing" for the NVM5 System. For the Guidance function, it explicitly mentions:
- Data Provenance: Clinical literature data. The references provided are from "J Neurosurg Spine, 2010" and "J Neurosurg Spine, 2009," suggesting the data would be retrospective and likely from various countries (though not specified, spine surgery research is often international).
- Sample Size: The document does not specify the sample size for the test set from these literature studies, nor does it provide a direct test set for the NVM5 System's Guidance functionality beyond comparing its performance to that presented in existing literature.
For the Bendini function, "nonclinical testing included evaluation of software performance per predetermined specifications outlined in the SRS." This indicates internal testing, but no sample size or data provenance (e.g., patient data) is provided.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
For the Guidance function, since the evaluation points to existing clinical literature, the "ground truth" would have presumably been established within those studies (e.g., confirmation of screw placement accuracy by post-operative imaging or surgical observation). The document does not specify the number or qualifications of experts involved in establishing this ground truth within the cited literature or for the NuVasive's internal comparison.
For other functions and general verification and validation, the document does not specify the number or qualifications of experts. Such testing typically involves engineers, quality assurance personnel, and potentially clinical consultants, but no details are provided here.
4. Adjudication Method for the Test Set
The document does not specify an adjudication method for any test set. Given the reliance on nonclinical testing and comparison to literature for the Guidance function, a formal adjudication process akin to those for AI clinical studies is not detailed.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
The document does not indicate that a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was done. The assessment focuses on the device's technical specifications and substantial equivalence to predicates, not on improvements in human reader performance with or without AI assistance. The NVM5 System itself is a surgical monitoring and guidance device, not primarily an AI-driven diagnostic imaging interpretation tool that would typically undergo MRMC studies.
6. Standalone (Algorithm Only) Performance Study
The document refers to "nonclinical testing" and "verification and validation testing" which implies standalone testing of the algorithm (software) components. For example:
- "NVM5 System Verification and Validation Testing"
- "NVM5 System software Regression Testing"
- "Nonclinical testing performed for the Bendini function included evaluation of software performance per predetermined specifications outlined in the SRS. GUI functionality, error handling, system accuracy during data acquisition, verification of instrument performance in combination with the software, and verification of software algorithms."
These statements suggest that the algorithm's performance was tested independently of direct human-in-the-loop clinical use, but the nature and scope of these standalone tests are not detailed beyond meeting predetermined specifications.
7. Type of Ground Truth Used
- For the Guidance function, the "ground truth" implicitly relies on the confirmed accuracy of pedicle screw placement as reported in the referenced clinical literature. This would typically be based on post-operative imaging outcomes data (e.g., CT scans reviewing screw position).
- For other nonclinical and software verification tests (e.g., Bendini, General NVM5 functions), the ground truth would be based on predetermined specifications and expected system outputs. For example, an electrical stimulation test would have a known target response, or software algorithm verification would test against a predefined correct output for a given input.
8. Sample Size for the Training Set
The document does not specify any training set sample size. The NVM5 System is a medical device for intraoperative monitoring and surgical guidance. While it employs software and algorithms, the filing describes it in terms of "substantial equivalence" to existing technologies rather than as a machine learning/AI device requiring distinct training and test sets in the modern sense. The algorithms are likely rule-based or signal processing-based, rather than learned from large datasets.
9. How the Ground Truth for the Training Set Was Established
As no training set is described, there is no information on how ground truth was established for a training set. The nature of the device (monitoring and guidance, rather than pattern recognition from large image sets) suggests that the "ground truth" for its development would be based on established neurophysiological principles, biomechanical models, and engineering specifications, rather than labeled training data.
§ 874.1820 Surgical nerve stimulator/locator.
(a)
Identification. A surgical nerve stimulator/locator is a device that is intended to provide electrical stimulation to the body to locate and identify nerves and to test their excitability.(b)
Classification. Class II.