(255 days)
The StealthStation® System is intended as an aid for precisely locating anatomical structures in either open or percutaneous procedures. The StealthStation® System is indicated for any medical condition in which the use of stereotactic surgery may be appropriate, and where reference to a rigid anatomical structure, such as the skull, a long bone, or vertebra, can be identified relative to a CT-based or MR-based model, fluoroscopy images, or digitized landmarks of the anatomy.
The StealthStation® System includes hardware and software that enables realtime surgical navigation using radiological patient images. The navigation system creates a translation map between points in the patient anatomy and the corresponding points on radiologic images of the patient. Once this map is established (through a process called registration), the software can display the relative position of a tracked instrument to a representation of the patient's anatomy. In this way the images can help guide the surgeon's planning and approach. Prior to operating, the surgeon may then create, store, and simulate progression along one or more surgical trajectories. As an aid to visualization, the surgeon may also create and manipulate one or more 2D or 3D models of the anatomy. During surgery, the system tracks the position of specialized surgical instruments in or on the patient anatomy and continuously updates the instrument position on these images either by optical tracking or electromagnetic tracking.
The operating system is software that controls the execution of programs, and that provides services such as resource allocation, scheduling, input/output control, and data management. This includes managing computer system hardware and software resources and providing a common set of services for software applications to interface with computing hardware.
Here's an analysis of the acceptance criteria and study information for the StealthStation® System, based on the provided 510(k) summary:
Acceptance Criteria and Device Performance
This 510(k) is for a minor modification to an existing device (predicate device K050438), specifically a change in the operating system from a proprietary Linux (GemOS) to Debian Linux. The rationale presented is that "No changes have been made to the StealthStation® operating principle or hardware due to the change to the operating system." Therefore, the primary acceptance criteria revolve around ensuring that this operating system change does not negatively impact the established performance of the predicate device and that the new system functions as expected.
Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria / Performance Aspect | Predicate Device K050438 Performance (as reference) | Subject Device (StealthStation® System with Debian Linux) Performance | Notes |
|---|---|---|---|
| Functional Verification | Not explicitly stated as a separate criterion in predicate's summary, but implied by original clearance. | "Verification successful, operating system fulfills all product requirements" | This criterion ensures the new operating system and its infrastructure correctly meet all defined product requirements. |
| Regression Verification | Not explicitly stated, implied by original clearance. | "Verification successful, unchanged but vulnerable portions of the product have not been adversely affected." | This criterion is crucial for changes to existing devices, ensuring that the new operating system does not introduce unintended negative effects on previously validated functionalities or components. |
| Validation (End-User Needs) | Not explicitly stated, implied by original clearance. | "All tests passed, which demonstrates that the product meets the needs of the end user." | This criterion confirms that despite the underlying operating system change, the overall system still effectively serves the intended purpose and meets the requirements of the clinicians who will use it. This often involves user testing scenarios to confirm usability and performance in a relevant context. |
| System Accuracy | "Stand-alone accuracy was reported in K050438" (performance deemed unchanged). | Identical to predicate (i.e., performance reported in K050438). | The 510(k) states that accuracy will not change, as the operating system change does not affect the core tracking and image guidance principles. The specific accuracy values for K050438 are not provided in this summary but are referenced as the benchmark. The study for K133444 implicitly relies on the continued validity of K050438's accuracy data. |
| Intended Use | Identical to K050438 | Identical to K050438 | The change in operating system does not alter the indications for use of the device. |
| Operating Principle (Tracking) | Identical to K050438 (Optical (infra-red), EM) | Identical to K050438 | The underlying tracking technology remains unchanged. |
| Control Mechanism (Hardware) | Identical to K050438 (Digitizer/Localizer, Computer, Reference Frames) | Identical to K050438 | The physical hardware components and their control mechanisms are not altered by the operating system change. |
Study Details for StealthStation® System (K133444)
The study described here is primarily focused on verification and validation (V&V) of a software update (operating system change), rather than a de novo clinical trial demonstrating efficacy of the device itself. The core performance of the device (e.g., accuracy) is established by the predicate device (K050438).
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Sample size used for the test set and the data provenance:
- Test Set Sample Size: Not explicitly stated as a numerical sample size of "cases" or "patients." The testing involved verification and validation activities on the software system itself. Given the nature of an operating system update, the "test set" would refer to a comprehensive suite of software tests, system configurations, and simulated or actual usage scenarios.
- Data Provenance: Not applicable in the context of patient data for this specific 510(k). The data comes from internal testing and verification activities of the software and system.
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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 summary. For software V&V, "ground truth" would be the expected behavior and output of the system according to its design specifications. This is typically established by design documentation and testing protocols, not necessarily clinical expert consensus in the way a diagnostic AI model would require. Software engineers and testers are the "experts" in this context, but their number and specific qualifications are not detailed.
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Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- Not applicable in the context of clinical adjudication for this type of software V&V testing. Software testing typically involves automated tests, manual testing by quality assurance engineers, and review against specifications. There's no mention of a "2+1" or similar adjudication process.
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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:
- No, an MRMC comparative effectiveness study was not done. This 510(k) is for a surgical navigation system, not a diagnostic AI device that assists human readers in interpreting images. The device itself is an aid for surgeons, and this submission focuses on a technical update, not a clinical effectiveness study.
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If a standalone (i.e., algorithm only without human-in-the loop performance) was done:
- Yes, in essence, standalone performance was assessed in terms of "System Accuracy" referenced from the predicate device (K050438). While this 510(k) does not provide new standalone accuracy data, it relies on the existing standalone accuracy data from K050438. The submission implicitly argues that since the operating system change doesn't affect the core algorithms or hardware, the standalone accuracy performance remains the same. The "functional" and "regression" verification also assess the system's performance in a standalone context (i.e., the software and hardware working correctly).
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- For the core functional accuracy of the navigation system itself (as established by the predicate K050438), the ground truth would typically be highly precise physical measurements (e.g., using a coordinate measuring machine (CMM) or other calibrated metrology equipment) to compare the system's reported position to the true physical position of a tracked instrument.
- For the current submission (K133444) focusing on the OS update, the "ground truth" for the verification and validation tests would be:
- Product Requirements/Specifications: The system is expected to perform according to its documented requirements.
- Expected Software Behavior: The new OS environment should not alter the functionality, stability, or performance of the application software compared to the previous OS.
- End-User Needs: The system should remain usable and effective for surgical navigation.
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The sample size for the training set:
- Not applicable. This device is a surgical navigation system, not a machine learning or AI model that requires a "training set" in the conventional sense. The "software" being updated is the operating system, which is a foundational component, not an algorithm trained on data.
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How the ground truth for the training set was established:
- Not applicable, as there is no training set in the context of this device.
§ 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).