(69 days)
The Elekta Stereotactic Guide is indicated for the guidance and stereotactic instrument positioning in open cranial procedures and surgeries normally performed with traditional stereotactic apparatus.
The Elekta Stereotactic Guide is an accessory to the Leksell Image Guidance Surgical (LIGS) System. The device consists of a base ring, targeting swivel with instrument channel, and locking ring. The guide and the LIGS are used for guidance and stereotactic instrument positioning during open cranial procedures and surgeries normally performed with traditional stereotactic apparatus. Once the target and entry point is determined during the presurgical planning phase, the craniotomy is made and the Elekta Stereotactic Guide is screwed into the patient's skull at the point of entry. The LIGS probe is placed into the guide and the orientation toward the target is determined using the intra-operative images. The guide is then locked into place and classic stereotactic instruments may then be placed into the channel of the guide for the surgical procedure.
Here's a summary of the acceptance criteria and study information for the Elekta Stereotactic Guide, based on the provided document:
The submission does not explicitly state quantitative acceptance criteria or a specific study designed to prove the device meets those criteria in a formal way (e.g., a hypothesis test against a predefined delta). Instead, it describes performance evaluations that show the device performs as intended.
1. Table of Acceptance Criteria and Reported Device Performance:
| Criteria/Characteristic | Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|---|
| Mechanical Accuracy | Comparable to stereotactic frames for biopsy needle measurements | Performed on a phantom model with biopsy needle measurements, compared to stereotactic frames. Studies show the device "performs as intended." |
| Clinical Performance | Guide and LIGS system perform as intended for guidance and stereotactic instrument positioning in open cranial procedures. | A clinical evaluation of 31 procedures documented "performs as intended." |
Explanation of "Implicit" Acceptance Criteria:
The document does not explicitly state specific quantitative acceptance criteria such as "accuracy must be within X mm" or "clinical success rate must be Y%." Instead, the studies aim to demonstrate that the device "performs as intended" and is equivalent to predicate devices. For mechanical accuracy, this implicitly means the accuracy achieved should be comparable to the established accuracy of traditional stereotactic frames. For clinical performance, it implies that the device successfully facilitates guidance and instrument positioning in actual surgical settings without adverse events or significant deviations from expected outcomes.
2. Sample Size Used for the Test Set and Data Provenance:
-
Mechanical Accuracy Study:
- Sample Size: Not explicitly stated regarding the number of measurements or phantom tests. It mentions "a phantom model" and "biopsy needle measurements" but not the quantity.
- Data Provenance: Not specified, but generally, phantom studies are conducted in a controlled lab setting and are not tied to specific countries or retrospective/prospective designations.
-
Clinical Evaluation:
- Sample Size: 31 procedures.
- Data Provenance: Not specified, but "clinical evaluation" typically implies prospective or retrospective collection of real-world patient data. The country of origin is not mentioned.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
This information is not provided in the document for either the mechanical accuracy study or the clinical evaluation.
4. Adjudication Method for the Test Set:
This information is not provided in the document.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done:
- No, an MRMC comparative effectiveness study was not done. The document describes mechanical and clinical evaluations, but not a study comparing human readers with and without AI assistance. The device is a physical stereotactic guide, not an AI-assisted diagnostic or therapeutic tool for human reader interpretation.
6. If a Standalone (algorithm only without human-in-the-loop performance) was done:
- Yes, a standalone evaluation was performed in essence, for the mechanical accuracy. The "mechanical accuracy study" on a phantom model can be considered a standalone evaluation of the device's physical precision, independent of direct human judgment during the measurement process, assuming automated or objective measurement techniques were used.
- The clinical evaluation involved human surgeons, but it's not framed as an algorithm-only test; rather, it assesses the device's function in a real-world surgical context.
7. The type of ground truth used:
- Mechanical Accuracy Study: The ground truth would likely be the known, precisely measured targets within the phantom model, against which the biopsy needle measurements guided by the device were compared. This is a form of objective physical measurement.
- Clinical Evaluation: The ground truth is implicit in the "procedures" themselves, reflecting the intended surgical outcome or successful instrument positioning as determined by the surgical team and confirmed through intra-operative imaging and post-procedure assessment. This would likely be clinical success and potentially patient outcomes, though specific metrics are not detailed.
8. The sample size for the training set:
- This information is not applicable/not provided. The device is a mechanical accessory, not a machine learning or AI algorithm that requires a training set.
9. How the ground truth for the training set was established:
- This information is not applicable/not provided for the same reason as point 8.
§ 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).