(70 days)
The Systems are intended for use as: devices that, by the use of diagnostic images of the patient, acquired specifically to assist the surgeon with presurgical planning, provide orientation and reference information during intra-operative procedures.
The Systems are indicated for use in: Guidance and localization in open craniotomies, and for surgeries that are traditionally performed with a stereotactic apparatus, such as biopsies, thalamotomies, and electrode implants. The Systems may also be used to review medical images in a neurosurgical context.
The MAYFIELD®/ ACCISS™ Operating Arm System with Windows NT® for Cranial Surgery and MAYFIELD® Optical ACCISS™ System with Windows NT® for Cranial Surgery and with the Wireless Probe/DRF are modifications to existing systems. The modifications involve converting the operating system software to Windows NT from DOS and adding a battery-powered Wireless Probe and battery-powered Wireless Dynamic Reference Frame for use with the Optical System. The systems use diagnostic images of the patient for presurgical planning and provide orientation and reference information during intra-operative procedures. The systems utilize either arm or optical tracking for 3-D digitizing, interface to a computer graphics workstation, display reformatted CT or MR images, and use algorithms for image-guided surgery planning.
The provided text is a 510(k) Summary for a medical device (MAYFIELD®/ACCISS™ System), describing modifications to existing systems. It focuses on demonstrating substantial equivalence to predicate devices rather than proving the device meets specific acceptance criteria through a clinical study. Therefore, much of the requested information regarding acceptance criteria and studies (like sample size, data provenance, expert ground truth, MRMC studies, standalone performance, training set details) is not present in this document.
However, based on the provided text, I can extract information related to the device's performance demonstration for substantial equivalence.
Here's a breakdown of what can and cannot be answered from the provided text:
1. A table of acceptance criteria and the reported device performance
The document does not specify formal "acceptance criteria" in terms of quantitative performance metrics (e.g., accuracy thresholds, sensitivity/specificity targets) for the new modifications. Instead, the "performance" demonstrated is that the modifications (Windows NT software and Wireless Probe/DRF) did not change the functionality of the systems compared to the predicate devices.
| Feature / Criteria (Implied) | Reported Device Performance (Modified System) |
|---|---|
| Intended Use | Same as predicate; unchanged. |
| Indications for Use | Same as predicate; unchanged. |
| Functions of Systems | Unchanged from predicate systems. |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
This information is not provided in the document. The text only states that "Tests simulating cranial surgery planning were performed." It does not specify the number of tests, the type of data (e.g., patient data, simulated models), or its provenance.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
This information is not provided. The text does not mention the use of experts to establish a "ground truth" for the testing in the context of clinical performance. The comparison was against the functional performance of the predicate devices.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
This information is not provided.
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
This is not applicable and not performed. The device described is a computer-based image-guided surgical planning system, not an AI diagnostic tool primarily impacting human reader performance. The modifications were to the operating system and a wireless accessory.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
A standalone performance evaluation in the typical sense of AI algorithms is not described. The "tests simulating cranial surgery planning" would inherently involve the system's functionality, but the document doesn't detail performance metrics like accuracy, precision, or error margins for the system itself. The focus was on comparing the modified system's operation to the predicate system's operation.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
The concept of "ground truth" in the context of clinical outcomes or diagnostic accuracy is not applicable to the described study. The study involved a functional comparison; the "ground truth" for these tests was the expected behavior and output of the predicate devices.
8. The sample size for the training set
This is not applicable and not provided. This document pertains to modifications of an existing image-guided surgery system, not the development or training of an AI algorithm from a training set.
9. How the ground truth for the training set was established
This is not applicable and not provided.
Summary of the Study (as described in the document):
The study performed was a comparative functional validation.
- Study Design: The manufacturer performed "Tests simulating cranial surgery planning" using the modified systems (Arm System with Windows, Optical System with Windows and Wireless Probe/DRF).
- Comparison: The results of these tests were "compared to the results of the same tests performed with the DOS-based Systems and with the wired Probe and DRF" (the predicate devices).
- Objective: To demonstrate that the "functions of the Arm and Optical Systems were unchanged" despite the modifications.
- Conclusion: Based on this comparison, the manufacturer concluded that the modifications "do not raise any new unresolved issues relating to safety and effectiveness" and that the modified systems are "substantially equivalent to the predicate Systems."
Essentially, the study aimed to show that changing the operating system and adding a wireless accessory did not alter the fundamental, proven functionalities of the existing medical devices.
§ 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).