(291 days)
Caduceus S is intended as an intraoperative gudance system to enable minimally invasive surgery. Intraoperatively registered surgical Instruments are tracked by a passive marker sensor system to virtual computer image space on a patient's preoperative or intraoperative 2D or 3D image data.
Caduceus S enables image-guide navigation of medical image data, which can either be acquired preoperatively CT or intraoperatively C-arm by an appropriate image acquisition system.
Caduceus S offers pedicle screw implant size planning and navigation on rigid bone structures with intraoperatively registered surgical Instruments.
Caduceus S is indicated for L5~T6 spine surgery where reference to a rigid anatomical structure can be identified relative to the acquired patient imagery (CT or C-arm).
The headset (Surglasses) of the Caduceus S system is an optional heads up display that projects the 2D stereotaxic screens of the system's display.
Caduceus S surgical navigation system is an image guidance system, which is composed of Navi Tracker, Surglasses, other hardware (Navigation Cart with an arm, Touch Screen, Router, Control System, Connection System), disposable tools (Disposable Passive Sphere, Straight Guide Pin, Navi Clamp Kit, Instrument Adapter Type A&B, Calibration Plate, Registration Kit, Correction Tool), reusable tools (Calibration Board, Instrument Holder), and Spine Navigation Software. Caduceus S is an optical tracking and guiding system for spine surgery. It can track the marks on the surgical instruments and patient's anatomical structure with marks, and register with the preoperative or intraoperative images of the patients. During the surgery, it can be displayed on the Touch Screen and the head mounted display Surglasses to provide the navigation for the surgical instruments.
Here's a breakdown of the acceptance criteria and the study proving the Caduceus S device meets them, based on the provided FDA 510(k) summary:
Acceptance Criteria and Device Performance
The core performance validation for this device, a surgical navigation system, relates to its accuracy in positioning and trajectory. The summary explicitly states:
| Acceptance Criteria | Reported Device Performance |
|---|---|
| System Level Accuracy | |
| Mean positional error ≤ 2.0 mm | CT Mode: Mean positional error = 1.91 mm (99% UBL* = 2.07 mm) |
| C-arm Mode: Mean positional error = 1.80 mm (99% UBL* = 2.06 mm) | |
| Mean trajectory error ≤ 2° | CT Mode: Mean angular error = 1.59° (99% UBL* = 1.71°) |
| C-arm Mode: Mean angular error = 1.65° (99% UBL* = 1.80°) | |
| Performance on head mounted display: FOV, resolution, luminance, transmission, distortion, contrast ratio, latency | The testing of device intended performance is successful, and all requirements are met. (Specific numerical values for these metrics are not provided in this summary but were likely documented in the full submission). |
*UBL = Upper Bound Limit (This indicates the upper limit of the confidence interval for the measured error, providing a statistical guarantee.)
Study Details
The primary study mentioned for evaluating device performance is a "System's accuracy" and "Performance and Usability of device intended use" study, which involved both phantom and cadaver studies.
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Sample Size and Data Provenance:
- Test Set Sample Size: The exact number of pedicle screws positioned or cases in the cadaver study is not explicitly stated as a number of subjects/specimens, but it mentions pedicle screws were positioned in L5-T6 spine. The testing was conducted in both "phantom and cadaver studies."
- Data Provenance: The document does not specify the country of origin for the cadaver data. It states the studies were non-clinical. The studies were retrospective in the sense that they were pre-market validation studies using pre-existing materials (phantoms, cadavers) to simulate real-world conditions.
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Number of Experts and Qualifications for Ground Truth:
- The document does not specify the number of experts used to establish the ground truth or their specific qualifications. It mentions that the positional error was derived from the "post-op scan" and its virtual tip as recorded by the Caduceus S system. This suggests the ground truth was established by comparing system output to a precise post-procedure imaging measurement.
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Adjudication Method:
- The document does not describe an adjudication method involving multiple human readers for the test set. The ground truth appears to be based on direct measurement from post-operative imaging.
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Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
- No MRMC comparative effectiveness study was done. The submission explicitly states: "No clinical test data was used to support the decision of substantial equivalence." This means no study was performed comparing human readers with and without AI assistance to measure improvement. The device is purely an intraoperative guidance system, and its validation focuses on its technical accuracy rather than interpretive diagnostic performance.
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Standalone Performance Study:
- Yes, a standalone study was performed. The described "System's accuracy" assessment is a standalone evaluation of the algorithm's output (positional and angular error) against the established ground truth (derived from post-op scans). This is algorithm-only performance without a human-in-the-loop directly influencing the measured accuracy metrics.
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Type of Ground Truth Used:
- The ground truth was established by measurements obtained from post-operative imaging (post-op scan). Specifically, for positional error, it was the difference between the actual screw tip position derived from the post-op scan and the system's recorded virtual tip. For trajectory error, it was the difference between the screw orientation and its recorded virtual trajectory. This closely aligns with "outcomes data" or highly precise "imaging-based comparison."
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Training Set Sample Size:
- The document does not specify the sample size used for the training set. This is a common omission in 510(k) summaries, as the focus is on the validation of the final device, not the development process.
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Ground Truth Establishment for Training Set:
- The document does not provide details on how ground truth was established for any training set. Given the nature of a 510(k) submission and the device (a surgical navigation system rather than a diagnostic AI), details on training data are typically less prominent in the publicly available summary unless directly relevant to a novel AI methodology requiring extensive clinical data for training. The performance validation relies on the non-clinical bench and cadaver studies.
§ 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).