(90 days)
Caduceus S is intended as an aid for precisely locating anatomical structures in percutaneous spine procedures. It is indicated for medical conditions in which the use of stereotactic surgery may be appropriate, when reference to a rigid anatomical structure, such as the spine or pelvis, can be identified relative to CT or 2D/3D C-arm images of the anatomy. This can include the spinal implant procedures, such as Posterior Pedicle Screw Placement in the thoracic and lumbosacral spine. Caduceus S offers pedicle screw implant size planning and navigation on rigid bone structures with intraoperatively registered surgical Instruments. The Headset of the Caduceus S displays 2D stereotaxic screens and a 3D anatomy model (floating). The displayed stereotaxic screens are indicated for correlating the tracked instrument location to the patient registered imagery to assist in percutaneous visualization and trajectory planning.
The Caduceus S system is an image-guided navigation system that is designed to assist surgeons in placing pedicle screws accurately, during percutaneous computer-assisted spinal surgery. The system consists of a dedicated software, Navigation Cart, Navi Tracker, Headset, Minimally Invasive Spine Surgery Instruments, Disposable Passive Spheres, and other disposable surgical consumables. It uses optical tracking technology and displays to the surgeon the location of the tracked surgical instruments relative to the acquired intraoperative patient's scan, onto the surgical field. The 2D scanned data and 3D reconstructed model, along with tracking information, are projected to the surgeons' eyes using a transparent near-eye-display Headset, allowing the surgeon to both look at the patient and the navigation data at the same time.
Here's a breakdown of the acceptance criteria and study information based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The provided text does not explicitly state acceptance criteria in a quantitative table format with corresponding performance results. Instead, it lists the types of tests performed and generally concludes that they were "successfully completed" or that the device "performs according to specifications and functions as intended."
However, we can infer the tested parameters and the general outcome:
| Acceptance Criteria (Inferred from tests) | Reported Device Performance (General Outcome) |
|---|---|
| Headset Display Performance: | |
| Resolution | Verified to perform as specified |
| Luminance | Verified to perform as specified |
| Transmission | Verified to perform as specified |
| Distortion | Verified to perform as specified |
| Contrast Ratio | Verified to perform as specified |
| Latency | Verified to perform as specified |
| Electrical Safety (IEC 60601-1:2012+A2:2020, EN 60601-1:2006+A11:2011+A1:2013+A12:2014+A2:2021) | Successfully completed |
| Electromagnetic Compatibility (IEC 60601-1-2:2014+AMD 1:2020) | Successfully completed |
| Sterilization Validation (ANSI/AAMI ISO 11135:2014/A1:2018) | Successfully completed |
| Shelf Life | Supported by testing |
| Packaging | Supported by testing |
| Cleaning and Sterilization Process of Reusables (SAL 10-6, ISO 17665-1, ISO 17664, FDA guidance) | Successfully completed |
| Biological Evaluation (ISO 10993 series) | New risks not introduced (covered by existing testing for modified instruments) |
| Repeatability and Accuracy (ASTM F2554) | Tested and demonstrated performance (specific values not provided in this text) |
| System's Clinical Accuracy (Cadaver Studies) | Screws positioned; positional and trajectory errors calculated; clinical accuracy evaluated using Gertzbein-Robbins score. Conclusion: Performs as intended. |
| Human Factors (observational data, interview data) | Confirmed safe and effective for intended users, uses, and environments |
| Software Verification and Validation (IEC 62304, FDA guidance) | Successfully completed |
2. Sample Size Used for the Test Set and Data Provenance
- Cadaver Studies: "three cadaver studies" were performed. The exact number of cadavers or individual screw placements is not specified.
- Human Factors: "Test participants representing the intended users" – the number of participants is not specified.
- Data Provenance: The document does not explicitly state the country of origin for the cadaver studies or human factors testing. It also doesn't specify if these were retrospective or prospective studies, though cadaver studies are inherently prospective for device testing.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not specify the number or qualifications of experts used to establish ground truth for the cadaver studies. It mentions that clinical accuracy was evaluated using the Gertzbein-Robbins score by viewing post-op scans, which implies expert review, but details are absent.
4. Adjudication Method for the Test Set
The document does not describe any specific adjudication method (e.g., 2+1, 3+1) for establishing ground truth or evaluating the test set results. The Gertzbein-Robbins score evaluation, while involving expert review, doesn't detail an adjudication process.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size
No, the provided text does not indicate that a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was done. Therefore, no effect size of human readers improving with AI vs. without AI assistance is reported. The study primarily focuses on the device's standalone performance and accuracy.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, standalone performance was assessed for various aspects of the device. For example:
- "Performance of the Headset display was demonstrated by verifying the following elements: Resolution, luminance, transmission, distortion, contrast ratio and latency."
- "Electrical safety was tested..."
- "Electromagnetic Compatibility (EMC) was tested..."
- "Repeatability and accuracy were tested according to ASTM F2554."
- "The system's accuracy was validated in three cadaver studies, in which screws were positioned in the positional and trajectory errors were calculated..." (This assesses the system's accuracy in guiding screw placement before considering human interpretation of the guidance).
The human factors study involved human interaction, but the underlying system accuracy tests are more akin to standalone performance evaluations.
7. The Type of Ground Truth Used
- Cadaver Studies: The ground truth for the cadaver studies involved "calculat[ing] the difference between the actual and virtual screw tip position, and the difference between the screw orientation and its recorded virtual trajectory." This implies a comparison against actual physical screw placement (measured by some means, likely post-placement imaging or direct measurement) versus the intended/navigated virtual trajectory. Additionally, "clinical accuracy was evaluated using the Gertzbein-Robbins score by viewing the post-op scans," suggesting radiological or surgical expert consensus based on image review as a ground truth for clinical relevance.
- Hardware and Software Performance: Ground truth was established by comparing device output (e.g., resolution, latency, electrical parameters) against engineering specifications, industry standards (IEC, EN), and regulatory guidance.
8. The Sample Size for the Training Set
The document does not provide any information regarding the sample size used for the training set. This section of the submission focuses on verification and validation testing, not algorithm training.
9. How the Ground Truth for the Training Set Was Established
Since no information on a training set is provided, there is no information on how its ground truth was established.
§ 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).