(57 days)
The Zeta Cranial Navigation System is a stereotaxic image guidance system intended for the spatial positioning and orientation of neurosurgical instruments used by surgeons. The device is indicated only for cranial surgery where reference to a rigid anatomical structure can be identified, does not require rigid fixation of the patient, and does not require fixation of a navigated instrument guide to the patient. The system is intended to be used in operating rooms and in less acute surgical settings such as interventional procedure suites.
The Zeta Cranial Navigation System is a stereotaxic, image guided planning and intraoperative guidance system enabling computer-assisted cranial interventional procedures. The system assists surgeons with the precise positioning of surgical instruments relative to patient anatomy by displaying the position of navigated surgical instruments relative to 3D preoperative medical scans.
Here's a breakdown of the acceptance criteria and study information for the Zeta Cranial Navigation System, based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
The document focuses on demonstrating substantial equivalence to a predicate device (Zeta Cranial Navigation System, K233903) rather than explicitly stating quantitative performance acceptance criteria in an easily digestible table. However, it implicitly uses various testing results to show the device meets safety and effectiveness requirements.
Below is an attempted table based on the provided information, where "Acceptance Criteria" are implied by successful test completion and "Reported Device Performance" is the outcome of those tests.
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Adherence to Biocompatibility Standards | Patient contact information is not needed as there are no direct or indirect patient-contacting components of the device. |
| Adherence to Electrical Safety Standards (IEC 60601-1) | The device passed all tests. |
| Adherence to Software Lifecycle Standards (IEC 62304) | The device passed all tests. |
| Adherence to Electromagnetic Compatibility (EMC) Standards (IEC 60601-1-2) | The device passed all tests. |
| Adherence to Usability Standards (IEC 60601-1-6) | The device passed all tests. |
| Software Verification and Validation | Testing was conducted, and documentation provided as recommended by FDA guidance. The software was considered a Major level of concern. |
| Cybersecurity Management | Documentation was provided as recommended by FDA guidance. |
| Cleaning and Sterilization Efficacy | The device is reusable, provided non-sterile, and is not sterile when used. Cleaning instructions are provided in the labeling. |
| Shelf Life (Stability) | Shelf-life is not applicable due to the low likelihood of time-dependent product degradation. |
| Accuracy under various conditions (simulated clinical procedures, surgical illumination, dynamic patient motion, worst-case physical/environmental conditions) | Tested and demonstrated substantial equivalence (implied satisfactory accuracy). |
| Design Validation | Performed to demonstrate substantial equivalence. |
| Human Factors and Usability | Testing was performed following FDA guidance. |
| Navigation Frames Per Second | Uncapped (mean 21fps) - Note: This is a performance metric, not an explicit acceptance criterion, but it implies meeting a functional requirement. |
2. Sample size used for the test set and the data provenance
The document does not specify a separate "test set" in the context of image data or patient studies for the subject device. The performance data provided is primarily from bench testing, electrical safety, software validation, and human factors testing.
Specifically, for accuracy testing, it mentions:
- "Simulated clinical procedures using virtual targets"
- "Surgical illumination levels"
- "Dynamic patient motion"
- "Other worst-case physical and environmental conditions"
However, the document does not provide details on:
- The sample size of virtual targets, simulated procedures, or specific cases used for accuracy testing.
- The provenance of any data (e.g., country of origin, retrospective/prospective) for these bench tests.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
This information is not provided in the document. The document describes bench testing and simulated environments rather than expert-adjudicated clinical data sets.
4. Adjudication method for the test set
This information is not provided as the testing described does not involve expert adjudication of a test set. The accuracy testing was likely measured against pre-defined virtual targets or established physical ground truths in a bench setting.
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
There is no mention of a multi-reader multi-case (MRMC) comparative effectiveness study being done, nor any data regarding human reader improvement with AI assistance. The Zeta Cranial Navigation System is described as an image guidance system for surgeons, not an AI-assisted diagnostic or interpretative tool for human readers of medical images.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
The document does not explicitly state "standalone performance" in the context of an algorithm. However, the accuracy testing and other bench tests (e.g., electrical safety, software validation) would inherently assess the device's functional performance independent of human interaction beyond operating the device. The "Navigation Frames Per Second" (mean 21fps) is a standalone performance metric for the system's real-time tracking capability.
7. The type of ground truth used
For the accuracy testing, the ground truth appears to be:
- Virtual targets: For simulated clinical procedures.
- Established physical ground truths: For accuracy measurements under various physical and environmental conditions.
The document does not mention pathology, outcomes data, or expert consensus as ground truth for the performance evaluations described.
8. The sample size for the training set
The document does not provide any information regarding a training set or its sample size. This is consistent with the device being primarily a navigation system, where the software's role is real-time tracking and display based on established principles, rather than a machine learning model that requires extensive training data for image interpretation or diagnosis.
9. How the ground truth for the training set was established
As no training set is mentioned, this information is not provided.
§ 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).