(198 days)
The Microtable System is intended to be used with commercially available stereotactic systems for intra-cranial and neurosurgical procedures which require the accurate positioning of microelectrodes, stimulating electrodes, or other instruments in the cranium, brain, or nervous system.
The Microtable System is a patient-specific surgical adapter, designed to be secured on a skull-based anchor mounting set to hold and align surgical instruments with patient anatomy and to allow selected targets to be reached with sub-millimeter accuracy. A Microtable System comprises an assembled Microtable, mounting hardware and tools, and cleaning and sterilization cases. The Microtable comprises the tabletop, legs, and an instrument mounting interface. The tabletop is designed specifically for the patient using the commercially available WayPoint™ Planning and Design software. Once the patient-specific tabletop is designed, the file is sent FHC, Inc. or to a qualified FHC OEM that will manufacture the tabletop using a CNC (Computer Numeric Controlled) mill. Each tabletop is patient-specific by milling at least three parallel leg holes and a hole for the instrument interface in a planar sheet of polycarbonate or Ultem. A qualified technician installs legs with appropriate lengths and rigidly attaches them to the tabletop along with the instrument interface. After fabrication and assembly, the tabletop is dimensionally verified to ensure that it meets all of the specifications and is shipped to the hospital for sterilization and use.
Here's a breakdown of the acceptance criteria and study information for the Microtable System, based on the provided 510(k) summary:
Microtable System Acceptance Criteria and Study Information
The Microtable System is a patient-specific surgical adapter designed for stereotactic neurosurgical procedures, aiming to achieve sub-millimeter accuracy in positioning instruments. The device's performance was evaluated against the predicate device, FHC, Inc.'s WayPoint™ Stereotactic System (K092192), focusing on dimensional stability, load-bearing capacity, and targeting accuracy.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criterion | Predicate Device Specification (Implicit) | Microtable System Performance | Result |
|---|---|---|---|
| Dimensional Stability | Maintained dimensional integrity post-sterilization | No dimensional change post-sterilization | PASS |
| Load Testing | Deflection within specified limits under load | Meets same specifications as predicate | PASS |
| Targeting Error (Accuracy) | Less than 1mm | Less than 1mm | PASS |
2. Sample Size and Data Provenance for Test Set
- Sample Size: The document does not specify the exact sample size for the test set. The nature of the device (patient-specific, custom-milled) suggests that physical units were likely tested. Without explicit numbers, it's difficult to quantify.
- Data Provenance: The testing was "nonclinical," meaning it was conducted in a lab setting rather than on human patients. The country of origin for the data is not explicitly stated, but given the submission to the FDA in the US, it's highly probable the testing was conducted within the United States. The studies are retrospective in the sense that they are laboratory tests performed on the manufactured device, not prospective clinical trials.
3. Number of Experts and Qualifications for Ground Truth Establishment (Test Set)
This information is not provided in the document. For a medical device like this, ground truth would likely be established through precise metrological measurements using calibrated equipment rather than human expert interpretation or consensus, which applies more to imaging or diagnostic devices.
4. Adjudication Method for the Test Set
This information is not applicable and not provided. Adjudication methods like 2+1 or 3+1 typically refer to the process of resolving discrepancies among multiple human readers for diagnostic output. For physical device performance tests, the results would be objective measurements.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No, an MRMC comparative effectiveness study was not done. This type of study is relevant for diagnostic devices where human readers interpret outputs (e.g., medical images) and AI might assist in that interpretation. The Microtable System is a surgical instrument, and its performance is measured through direct physical properties and accuracy, not through human interpretation of a diagnostic output.
6. Standalone Performance Study (Algorithm Only Without Human-in-the-Loop Performance)
- Yes, a standalone study was performed. The nonclinical performance data – dimensional stability, load testing, and targeting error – describes the inherent characteristics of the Microtable System itself, independent of immediate human interaction during the test procedures. These tests evaluate the device's functional attributes and accuracy. The device itself is "passive" and "immutable" once fixed to the patient, as stated in the submission.
7. Type of Ground Truth Used
The ground truth used for these tests would be based on:
- Metrology and Engineering Specifications: For dimensional stability, the ground truth is the initial design specification and precise measurements. For load testing, it's the predefined load capacity and acceptable deflection limits. For targeting error, the ground truth is the precise, intended target point established by the design and measured by high-precision instruments.
- This is not "expert consensus," "pathology," or "outcomes data" in the typical sense, but rather objective, quantifiable engineering and metrological standards adhered to during design and manufacturing.
8. Sample Size for the Training Set
- Not Applicable / Not Provided. The Microtable System is a mechanical device, not an AI/machine learning algorithm that requires a "training set" in the conventional sense. The "design" using the WayPoint™ Planning and Design software is based on patient-specific data (CT/MR images, fiducial markers, neurosurgeon's trajectory) at the planning stage for each individual patient, leading to a unique, custom-milled tabletop. This is a design and manufacturing process, not an AI training process.
9. How Ground Truth for the Training Set Was Established
- Not Applicable / Not Provided. As explained above, there is no "training set" for the Microtable System in the context of an AI algorithm learning from data. The design of each patient-specific Microtable relies on the pre-operative planning process, where the neurosurgeon defines the trajectory and the software uses patient imaging data and anatomical landmarks (AC, PC, mid-plane point) to generate the specific design. The accuracy of this design relies on the validated WayPoint™ Planning and Design software and the neurosurgeon's inputs.
§ 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).