(138 days)
Phasor EZ-Fiducials is intended to provide fixed reference point(s) in patients requiring stereotactic surgery in conjunction with CT imaging with the included screws placed using the included EZ-Driver (electric screwdriver) or manual screwdriver exclusively for each.
Phasor EZ-FIDUCIALS™ provide fixed reference points during neurosurgical procedures. The device is composed of 3 items, all single-use, provided gamma-sterilized, and placed within the same primary packaging (sealed Tyvek tray within a shelf carton):
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Screws: Each of the four provided titanium screws is identical, with specific dimensions of each EZ-Fiducials screw as follows: screwhead circular shape screwhead with square-shaped engagement, non-threaded shaft diameter 2.9mm and length 15mm, threaded shaft diameter (major threads) 1.98mm, thread length 5mm; no protective caps are provided, and the screws should exclusively be utilized in conjunction with the screwdrivers (manual or EZ-Driver) provided together in the same tray (and with no other screwdriver);
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Manual Screwdriver: handheld, to be solely used with the screws provided, not intended for use with any other screws;
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EZ-driver: (electric, handheld, non-rechargeable battery-operated screwdriver, without software, single-use for solely tightening or loosening the provided screws exclusively, not intended for use with any other screws).
The provided FDA 510(k) clearance letter and summary for EZ-Fiducials focuses primarily on substantial equivalence to predicate devices based on technological characteristics and bench testing, rather than a clinical study with acceptance criteria based on human-in-the-loop performance or algorithm-only performance against a defined ground truth.
Therefore, for aspects related to "device performance," "acceptance criteria," "sample size," "expert ground truth," "adjudication methods," "MRMC studies," "standalone performance," and "ground truth for training/test sets," the available document does not provide this information. The submission relies on bench testing to demonstrate equivalence.
Here's an analysis of what information is provided and what explicitly is not provided based on your request:
Acceptance Criteria and Device Performance (Based on Available Information)
The document does not present a table of acceptance criteria and reported device performance in the manner typically seen for clinical or AI/algorithm performance studies (e.g., sensitivity, specificity, accuracy). Instead, it relies on demonstrating compliance with an ASTM standard and general performance adequacy, often by comparison to predicate devices' known characteristics.
Table of Acceptance Criteria and Reported Device Performance (as inferred from the document):
| Acceptance Criteria Category (Inferred) | Specific Standard/Requirement | Reported Device Performance (EZ-Fiducials) | Met? |
|---|---|---|---|
| Material Biocompatibility | Biocompatible materials | Yes | Yes |
| Sterility | Gamma-sterilized | Yes, single-use, gamma-sterilized | Yes |
| Single-use | Disposable | Yes | Yes |
| Fiducial Screw Purchase/Deflection | Firm purchase into bone simulant; compliant with ASTM F543-23 | Verified by testing for deflection using CMM; compliant with ASTM F543-23 | Yes |
| Electric Screwdriver Functionality | Ability to drive/remove screws; adequate performance (per report "02670-019011-1" including Table 6) | Performs adequately, speed 30rpm (different from reference 120rpm, but supported by performance testing) | Yes |
| Packaging Integrity | Maintain sterility | Sealed Tyvek tray within a shelf carton | Yes |
| Safety Considerations | Safe operation | No negative impact on safety compared to predicates | Yes |
Study Proving Device Meets Acceptance Criteria
The study proving the device meets acceptance criteria is primarily bench testing. No clinical study data is presented.
1. A table of acceptance criteria and the reported device performance:
- See table above. This is inferred from the discussion of performance testing. Explicit quantitative acceptance criteria (e.g., "deflection must be less than X mm") are not detailed, but compliance with ASTM F543-23 and "adequate performance" are stated.
2. Sample size used for the test set and the data provenance:
- Sample Size: Not explicitly stated for bench testing. The testing refers to "bone simulant" but the quantity of fiducials, screws, or instances tested is not specified.
- Data Provenance: Not applicable in terms of patient data. The testing is bench testing using "bone simulant." There is no indication of retrospective or prospective data or country of origin, as it's not a clinical study.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not applicable. This was a bench study, not a study requiring expert ground truth for clinical cases. The "ground truth" for the bench testing would be physical measurements and compliance with engineering standards.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- Not applicable. There was no human interpretation or subjective assessment of clinical data that would require adjudication.
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:
- No. An MRMC study was not done. The device is a physical fiducial system and an electric screwdriver, not an AI or software device that assists human readers.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Not applicable. This is not an AI algorithm. The device performance here refers to the physical characteristics and functionality of the fiducials and screwdriver.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc):
- Bench Testing Data/Engineering Standards. The ground truth for this submission's performance assessment is the physical performance and measurements of the device (deflection) and compliance with industry standards (ASTM F543-23).
8. The sample size for the training set:
- Not applicable. This device does not use machine learning or AI, so there is no training set.
9. How the ground truth for the training set was established:
- Not applicable. As above, no training set.
Summary of the Study:
The "study" referenced in the 510(k) for EZ-Fiducials is a series of bench tests focusing on:
- Biocompatibility of materials.
- Sterility validation.
- Packaging integrity.
- Performance of the screws (e.g., deflection characteristics, compliance with ASTM F543-23 when inserted into bone simulant).
- Performance of the electric screwdriver (its ability to drive screws adequately).
The clearance is based on the argument that these bench tests demonstrate the device's substantial equivalence in terms of safety and effectiveness to the predicate device (Medtronic Navigus Unibody Fiducial Marker System) and a reference device (OsteoMed Pinnacle Driver), even with some technological differences (e.g., screwdriver speed, sterilization method). The document explicitly states: "No clinical testing was needed or performed otherwise." The predicate device was also "cleared based upon bench testing alone."
§ 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).