(30 days)
Pulse Navigation is intended as an intraoperative image-guided localization system in either open or minimally invasive spinal surgical procedures. Instruments and implants tracked by a passive marker sensor system are virtually displayed on a patient's 3D radiographic image data. The system enables computer-assisted navigation for spinal surgical procedures in which the use of stereotactic surgery may be appropriate and where a reference to a rigid anatomical structure can be identified relative to the acquired image of the anatomy.
This may include the following spinal implant procedures:
- Pedicle Screw Placement (cervical, thoracic, lumbar)
- Iliosacral screw placement
The subject device, Pulse ICT Adapter is introducing compatibility based on the design of existing fria patient reference hardware, the Spinous Process Clamp (Pulse System K210574) and Globus Medical 1CT Fixture (ExcelsiusGPS K171651 and K 191100). The subject device, Pulse ICT Adapter was designed to offer surgeons more flexibility during the registration process of Pulse Navigation by providing an additional patient reference hardware design option by attaching Globus Medical Intra-Op CT Fixture to the following: existing Articulating Arm and Bedrail Clamp. Despite the changes introduced to predicate Spinous Process Clamp (K210574), the subject device is substantially equivalent to the predicate as demonstration and validation testing performed using well established and previously cleared test methods.
The Pulse System is a medical device consisting of Pulse LessRay, and Pulse Navigation. The Pulse System hardware includes a control unit, as well as accompanying accessory components.
The Pulse NVM5 is a medical device that is intraoperative neurological monitoring and status assessment during spinal surgery. The device provides information directly to the surgeon, to help assess a patient's neurological status. The Pulse NVMS provides this information by electrically stimulating nerves via electrodes located on surgical accessories and monitoring electromyography (EMG), motor evoked potential (MEP) or somatosensory evoked potential (SSEP) responses of the muscle groups innervated by the nerves. Moreover, a Twitch Test ("Train of Four") function is utility of the nerve to respond, or contract, following four stimulation pulses to determine the presence of neuromuscular block.
Additionally, the Pulse NVM5 System includes a software function that measures spinal parameters and acquires the location of spinal implants (screws, hooks) to assist the surgeon in bendini). Lastry, the Pulse NVMS provides Remote Access in two pathways, Local Wireless Control and Remote Monitoring.
Pulse LessRay is a software application which can be interfaced to a fluoroscope with a video cable. The images produced by the fluoroscope are transmitted to a frame grabber in the computer running LessRay where the images are enhanced and then displayed. When used in connection with the low dose and/or pulse setting on the fluoroscope, the user can improve the quality (clarity, contrast, noise level, and usability) of a noisy (low-quality) image. Using this system, much of the graininess of low radiation dose images can be eliminated. This allows for greater utility of low dose imaging. LessRay provides the additional feature of being able to interface LessRay with a tracking system in order to aid the C-arm technician in positioning the fluoroscope between the various views of the patient necessary for the intervention. LessRay with Tracking ensures that the fluoroscope is centered over the correct anatomy prior to taking any additional x-ray images.
Pulse Navigation is a stereotactic surgical as an aid for precisely locating anatomical structures in either open or percutaneous procedures. It is intended for intraoperative image-guided localization which allows for surgical instruments to be tracked in three-dimensional space. The device provides real-time information directly to the surgeon to evaluate the instrument depth and trajectory for computer-assisted navigation during spine surgery. Instruments are tracked in threedimensional space with an Infrared (IR) Camera, being virtually displayed and superimposed on registered radiographic images. Radiographic images are in the form of 3D intraoperative scan (CT or Cone Beam CT).
The reason for the submission is to introduce a new intra-operative CT (ICT) adapter for use with the ExcelsiusGPS ICT Registation Fixture for the Pulse Navigation application.
The provided documentation (K243814) describes the NuVasive Pulse System (specifically, the Pulse ICT Adapter), a stereotaxic instrument for image-guided spinal surgery. The submission focuses on introducing a new intra-operative CT (ICT) adapter for use with the ExcelsiusGPS ICT Registration Fixture for the Pulse Navigation application.
The document does not provide a comprehensive study proving the device meets specific acceptance criteria in the format requested (e.g., performance metrics like sensitivity, specificity, or accuracy compared to a ground truth established by experts). Instead, it focuses on demonstrating substantial equivalence to predicate devices through verification testing.
However, based on the information provided, we can infer some aspects related to acceptance criteria and the testing performed.
Here's an attempt to answer your questions based on the available text:
1. A table of acceptance criteria and the reported device performance
The document does not present a table of specific quantitative acceptance criteria or detailed performance results in the usual sense (e.g., sensitivity, specificity, accuracy for a diagnostic AI). Rather, it states that "the subject Pulse System meets product and software for the system and satisfies the same acceptance criteria as the predicate device."
The performance testing mentioned is primarily focused on verification and validation to ensure compliance with design specifications and user needs, particularly regarding tracking accuracy and usability.
| Acceptance Criteria (Inferred/General) | Reported Device Performance |
|---|---|
| Compliance with design specifications | "The results of testing demonstrated that the subject Pulse System meets product and software [requirements] for the system." |
| Compliance with user needs | "Non-clinical system, software, and instrument verification and validation demonstrated compliance with user needs and corresponding design inputs." and "Qualitative validation to confirm intended use." |
| Tracking Accuracy | "Testing was performed to ensure compliance with recognized standards mentioned below for tracking accuracy..." Specifically, ASTM F2554-10: Standard Practice for Measurement of Positional Accuracy of Computer Assisted Surgical Systems is cited. The actual measured accuracy values are NOT provided in this document. |
| Usability | "Testing was performed to ensure compliance with recognized standards mentioned below for... usability." Specifically, IEC 62366:2020 Medical devices Part 1: Application of usability engineering to medical devices is cited. Detailed usability test results are NOT provided. |
| Software Lifecycle Processes and Safety | Compliance with IEC 62304:2015 Medical device software - Software lifecycle processes is mentioned, indicating adherence to software development and safety standards. No specific performance metrics for this are provided beyond general compliance. |
| Substantial Equivalence to Predicate Devices | "The results of testing demonstrated that the subject Pulse System... satisfies the same acceptance criteria as the predicate device." and "Based on the indications for use, technological characteristics, and comparison to predicate devices, the subject device has been shown to be substantially equivalent to legally marketed predicate devices." This is the primary "performance" claim for regulatory clearance. |
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 does not specify a "sample size" for a test set in terms of patient data or images (as would be common for AI/ML diagnostic devices). The testing described is non-clinical verification and validation. This would typically involve physical testing on phantoms or test setups rather than patient data.
- Sample Size: Not specified in terms of patient cases. The testing would be on a sufficient number of test samples/setups to prove the specific engineering requirements and standards.
- Data Provenance: Not applicable as it's non-clinical testing. The tests are performed in a laboratory/engineering environment.
- Retrospective/Prospective: Not applicable.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g., radiologist with 10 years of experience)
This document describes a surgical navigation system, not a diagnostic AI that interprets images. Therefore, the concept of "experts establishing ground truth for a test set" in the radiological interpretation sense does not apply directly.
The "ground truth" for a surgical navigation system's accuracy would be established through precise metrological measurements using phantoms or physical setups, not expert human agreement on medical images.
For usability testing (IEC 62366), "users" (e.g., simulated surgeons or clinical personnel) would interact with the device, and their feedback/performance would be assessed, but this is different from establishing a diagnostic ground truth.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set
Not applicable, as this is not a study requiring expert adjudication of medical images.
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
No such MRMC study is described in this document. The device is a surgical navigation system, not an AI for image interpretation or a tool to assist human readers in diagnosis.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done
This also doesn't directly apply. The "algorithm" (Pulse Navigation) is inherently human-in-the-loop: it assists the surgeon. The "standalone" performance would be its tracking accuracy and computational correctness, which are assessed through the non-clinical verification as per ASTM F2554-10. The document states this testing was done to ensure the system meets its specifications.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
For the aspects of the device discussed (tracking accuracy, usability), the "ground truth" would be established by:
- Metrological standards: For tracking accuracy (e.g., using precise measurement tools and phantoms as per ASTM F2554-10). The true position would be known and deviations measured.
- Engineering specifications and user requirements: For general system functionality and safety.
- Usability engineering principles: For usability testing, where adherence to principles defined in standards like IEC 62366 is verified.
8. The sample size for the training set
This document does not describe an AI/ML device that undergoes a "training phase" on a dataset in the sense of deep learning or machine learning. The device is a hardware/software system that uses pre-defined algorithms for navigation and tracking. Therefore, there is no "training set" in the context of data-driven model learning.
9. How the ground truth for the training set was established
Not applicable as there is no "training set" in the AI/ML sense. The system's algorithms are developed based on established engineering principles and physics.
§ 882.4560 Stereotaxic instrument.
(a)
Identification. A stereotaxic instrument is a device consisting of a rigid frame with a calibrated guide mechanism for precisely positioning probes or other devices within a patient's brain, spinal cord, or other part of the nervous system.(b)
Classification. Class II (performance standards).