(58 days)
Synergy Cranial v2.2.9:
The StealthStation System, with Synergy Cranial software, is intended as an aid for precisely locating anatomical structures in either open or percutaneous neurosurgical procedures. The system is indicated for any medical condition in which reference to a rigid anatomical structure can be identified relative to images of the anatomy. This can include, but is not limited to, the following cranial procedures:
- Cranial Biopsies
- Tumor Resections
- Craniotomies/Craniectomies
- Skull Base Procedures
- Transsphenoidal Procedures
- Thalamotomies/Pallidotomies
- Pituitary Tumor Removal
- CSF Leak Repair
- Pediatric Catheter Shunt Placement
- General Catheter Shunt Placement
StealthStation Cranial Software v3.1.4:
The StealthStation System, with StealthStation Cranial software, is intended to aid in precisely locating anatomical structures in either open or percutaneous neurosurgical procedures. The system is indicated for any medical condition in which reference to a rigid anatomical structure can be identified relative to images of the anatomy. This can include, but is not limited to, the following cranial procedures (including stereotactic frame-based and stereotactic frame alternatives-based procedures):
- Cranial biopsies (including stereotactic)
- Deep brain stimulation (DBS) lead placement
- Depth electrode placement
- Tumor resections
- Craniotomies/Craniectomies
- Skull Base Procedures
- Transsphenoidal Procedures
- Thalamotomies/Pallidotomies
- Pituitary Tumor Removal
- CSF leak repair
- Pediatric Ventricular Catheter Placement
- General Ventricular Catheter Placement
The StealthStation System, with StealthStation Cranial software helps guide surgeons during cranial surgical procedures such as biopsies, tumor resections, and shunt and lead placements. The StealthStation Cranial software works in conjunction with an Image Guided System (IGS) which consists of clinical software, surgical instruments, a referencing system and platform/computer hardware. Image guidance, also called navigation, tracks the position of instruments in relation to the surgical anatomy and identifies this position on diagnostic or intraoperative images of the patient. StealthStation Cranial software functionality is described in terms of its feature sets which are categorized as imaging modalities, registration, planning, interfaces with medical devices, and views. Feature sets include functionality that contributes to clinical decision making and are necessary to achieve system performance.
The Medtronic Navigation, Inc. StealthStation Cranial Software (v3.1.4) and Synergy Cranial Software (v2.2.9) are image-guided surgery (IGS) systems intended to aid in precisely locating anatomical structures during neurosurgical procedures.
Here's an analysis of the acceptance criteria and study that proves the device meets them, based on the provided FDA 510(k) summary:
1. Table of Acceptance Criteria and Reported Device Performance
The primary acceptance criteria for both software versions are related to system accuracy in 3D positional and trajectory angle measurements.
| Acceptance Criteria (Synergy Cranial v2.2.9 & StealthStation Cranial v3.1.3/v3.0) | Reported Device Performance (Synergy Cranial v2.2.9) | Reported Device Performance (StealthStation Cranial v3.1.3/v3.0) |
|---|---|---|
| System Accuracy: | ||
| 3D positional accuracy: mean error ≤ 2.0 mm | 1.29 mm | 1.27 mm |
| Trajectory angle accuracy: mean error ≤ 2.0 degrees | 0.87 degrees | 1.02 degrees |
Note: The document refers to "StealthStation Cranial v3.1.3" and also "StealthStation Cranial v3.0 Software" in the testing section for the newer version's accuracy. Assuming v3.1.3 is the subject device and v3.0 is a close predecessor or the system version used for the test. The "v3.1.4" in the 510(k) letter is likely a minor update from v3.1.3, and the reported performance for v3.1.3 is considered representative.
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state the sample size (number of patients or phantom configurations) used for the quantitative accuracy testing (test set). It mentions:
- "Under representative worst-case configuration"
- "utilizing a subset of system components and features that represent the worst-case combinations of all potential system components."
- "Test configurations included CT images with slice spacing and thickness ranging between 0.6 mm to 1.25 mm and T1-weighted MR images with slice spacing and thickness ranging between 1.0 mm to 3.0 mm."
Data Provenance: The data appears to be prospective as it was generated through laboratory and simulated use settings with "anatomically representative phantoms." The country of origin is not explicitly stated, but given Medtronic Navigation, Inc. is located in Louisville, Colorado, USA, it's highly probable the testing was conducted in the USA.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
The document indicates that the accuracy was determined using "anatomically representative phantoms." This implies that the ground truth for positional and angular accuracy was engineered and precisely measured within a controlled phantom environment, rather than established by human experts interpreting clinical data. Therefore, human experts were likely involved in designing and validating the phantom setup and measurement methodologies, but not in directly establishing ground truth from patient data. The qualifications of these individuals are not specified but would typically be engineers, physicists, or metrology specialists.
4. Adjudication Method for the Test Set
Given that the ground truth was established through a designed phantom and precise measurements, an adjudication method for human interpretation is not applicable here. The measurements are objective and quantitative.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No MRMC comparative effectiveness study was mentioned for human readers improving with AI vs. without AI assistance. The device is a surgical navigation system, aiding in real-time guidance, not an AI-assisted diagnostic tool that would typically undergo MRMC studies.
6. Standalone (i.e., algorithm only without human-in-the-loop performance)
Yes, a standalone performance was done for the system's accuracy. The reported positional and trajectory angle errors are measures of the system's inherent accuracy, independent of a specific human-in-the-loop scenario. The study describes "Design verification and validation was performed using the StealthStation Cranial software in laboratory and simulated use settings."
7. The Type of Ground Truth Used
The ground truth used was engineered truth derived from precisely measured anatomical phantoms. This is a highly controlled and quantitative method, suitable for measuring the accuracy of a navigation system.
8. The Sample Size for the Training Set
The document does not describe a "training set" in the context of an AI/machine learning model. The device is referred to as "software" for an Image Guided System (IGS), which typically relies on established algorithms for image processing, registration, and tracking, rather than deep learning models that require large training datasets with ground truth labels in the conventional sense. The "training" for such a system would involve rigorous formal verification and validation of these algorithms.
9. How the Ground Truth for the Training Set Was Established
As noted above, the concept of a "training set" and its associated ground truth, as typically applied to AI/machine learning, does not appear to be directly applicable to the description of this device's development as presented in the 510(k) summary. The development involved "Software verification and validation testing for each requirement specification" and "System integration performance testing for cranial surgical procedures using anatomical phantoms," suggesting traditional software engineering and testing methodologies rather than machine learning training.
§ 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).