(29 days)
SpineAR SNAP is intended for use for pre-operative surgical planning on-screen and in a virtual environment, and intraoperative surgical planning and visualization on-screen and in an augment using the HoloLens2 and Magic Leap 1 AR headset displays with validated navigation systems as identified in the device labeling.
SpineAR SNAP is indicated for spinal stereotaxic surgery, and where reference to a rigid anatomical structure, such as the spine, can be identified relative to images of the anatomy. SpineAR is intended for use in spinal implant procedures, such as Pedicle Screw Placement, in the lumbar and thoracic regions with the Magic Leap 1 and HoloLens2 AR headsets.
The virtual display should not be relied upon solely for absolute positional information and should always be used in conjunction with the displayed 2D stereotaxic information.
The SpineAR SNAP does not require any custom hardware and is a software-based device that runs on a high-performance desktop PC assembled using "commercial off-the-shelf" components that meet minimum performance requirements.
The SpineAR SNAP software transforms 2D medical images into a dynamic interactive 3D scene with multiple point of views for viewing on a high-definition (HD) touch screen monitor. The surgeon prepares a pre-operative plan for stereotaxic spine surgery by inserting guidance objects such as directional markers and virtual screws into the 3D scene. Surgical planning tools and functions are available on-screen and when using a virtual reality (VR) headset. The use of a VR headset for preoperative surgical planning further increases the surgeon's immersion level in the 3D scene by providing a 3D stereoscopic display of the same 3D scene displayed on the touch screen monitor.
By interfacing to a 3rd party navigation system such as a Medtronic StealthStation S8, the SpineAR SNAP extracts the navigation data (i.e. tool position and orientation) and presents the navigation data into the advanced interactive, high quality 3D image, with multiple point of views on a high-definition (HD) touch screen monitor. Once connected, the surgeon can then execute the plan through the intraoperative use of the SpineAR SNAP's enhanced visualization and guidance tools.
The SpineAR SNAP supports three (3) guidance options from which the surgeon selects the level of guidance that will be shown in the 3D scene. The guidance options are dotted line (indicates deviation distance), orientation line (indicates both distance and angular deviation), and ILS (indicates both distance and angular deviation using crosshairs). Visual color-coded cues indicate alignment of the tracker tip to the guidance object (e.g. green = aligned).
The 3D scene with guidance tools can also be streamed into an AR wireless headset (Magic Leap 1 or HoloLens2) worn by the surgeon during surgery. The 3D scene and guidance shown within the AR headset is projected above the patient and does not obstruct the surgeon's view of the surgical space.
The provided text describes the acceptance criteria and the study conducted to prove that the SpineAR SNAP device meets these criteria, specifically addressing the expansion of its indications for use with the HoloLens2 AR headset to include the thoracic region in addition to the lumbar region.
Here's a breakdown of the requested information:
1. A table of acceptance criteria and the reported device performance
The acceptance criteria are presented as "Accuracy Requirement" in the table, and the "HoloLens2 AR Headset Results" are the reported device performance for the subject device.
| Metric | Acceptance Criteria | Reported Device Performance (HoloLens2 AR Headset Results) |
|---|---|---|
| Mean Positional/Displacement Error | ≤ 2.0 mm | 0.76 mm |
| Max Positional/Displacement Error | ≤ 3.0 mm | 1.47 mm |
| Mean Trajectory/Angular Error | ≤ 2° | 1.73° |
| Max Trajectory/Angular Error | ≤ 3° | 2.96° |
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 the exact sample size (number of screws or spine models) used for the test set. It only mentions that the final placement of "each screw in a spine model" was assessed.
The data provenance is not explicitly stated in terms of country of origin or whether it was retrospective or prospective. However, the study describes a controlled performance test involving a "spine model," suggesting a prospective, in-vitro (non-human) study designed to evaluate accuracy.
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)
The document does not specify the involvement of human experts for establishing the ground truth of the pedicle screw placement in this particular performance study. The ground truth appears to be established through "post-surgical CT scan" data compared to a "pre-surgical plan."
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
No adjudication method involving human experts is described for this performance study. The assessment of screw placement was based on quantifiable measurements derived from CT scans.
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
A Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not performed. This study focuses on the device's accuracy in a non-human, simulated environment (spine model) and compares the HoloLens2 performance to the previously cleared Magic Leap 1. It does not evaluate human reader performance or the improvement with AI assistance.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This study is essentially a standalone (algorithm only) performance assessment, although the device (SpineAR SNAP) is an augmented reality system intended for human use. The performance test specifically evaluates the accuracy of the system's guidance during simulated pedicle screw placement, independent of the surgeon's skill. The "human-in-the-loop" aspect during clinical use is acknowledged, but the performance testing here isolates the device's accuracy in a controlled setup.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The ground truth used was objective quantitative measurements derived from post-surgical CT scans of a spine model, which were then compared against the pre-surgical plan. This is a form of objective physical ground truth.
8. The sample size for the training set
The document does not provide any information about the training set size or methodology. This submission is for a modification to an existing device (expanding indications for an existing AR headset), not the initial development or de novo clearance of the core algorithm.
9. How the ground truth for the training set was established
As no information on a training set is provided, how its ground truth was established is also not detailed. The current study focuses on validation of expanded indications through performance testing only.
§ 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).