(68 days)
The Modified Ureteral Stent is intended to facilitate drainage from the kidney to the bladder via placement transurethrally, percutaneously, or via open surgery by a trained physician.
Modified Ureteral Stent
The provided text pertains to a 510(k) premarket notification for a Modified Ureteral Stent by Boston Scientific Corporation. This type of submission focuses on demonstrating substantial equivalence to a predicate device rather than presenting detailed experimental studies with acceptance criteria, sample sizes, or ground truth establishment in the way one would for novel AI/diagnostic devices.
Therefore, most of the requested information (acceptance criteria, specific study details with sample sizes, ground truth, expert qualifications, adjudication, MRMC, or standalone performance for an algorithm) is not applicable to this 510(k) submission for a traditional medical device like a ureteral stent.
Here's an analysis based on the provided text, addressing the applicable points:
1. A table of acceptance criteria and the reported device performance
- Acceptance Criteria: Not explicitly stated as quantifiable acceptance criteria in the manner of a diagnostic study (e.g., sensitivity/specificity thresholds). The primary "acceptance criterion" for a 510(k) is demonstrating substantial equivalence to existing legally marketed predicate devices.
- Reported Device Performance: The document states: "The proposed modified device is Substantially Equivalent to the predicate devices in terms of performance characteristics tested." It does not provide specific performance metrics (e.g., flow rates, durability, biocompatibility test results) that would typically be associated with acceptance criteria for a new device. The performance is assessed against the predicate device's known performance.
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Substantial Equivalence to predicate devices for performance characteristics. (Implicit within 510(k) process) | "The proposed modified device is Substantially Equivalent to the predicate devices in terms of performance characteristics tested." |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Not applicable. The submission does not describe a clinical study with a "test set" in the context of a diagnostic algorithm. 510(k)s for traditional devices usually rely on bench testing, materials characterization, and potentially limited animal or human use data (sometimes referred to as "clinical data" but rarely a formal "test set" as in AI studies) to support substantial equivalence. The document does not provide details on such testing.
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)
- Not applicable. There is no "ground truth" to establish in the context of a ureteral stent's performance in the same way there would be for a diagnostic AI device. The ground truth for device function is based on engineering specifications, material properties, and clinical outcomes attributed to the device type.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not applicable. No adjudication method is described, as there's no diagnostic "test set" that requires expert consensus.
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
- Not applicable. This device is a modified ureteral stent, not an AI or imaging diagnostic device. Therefore, no MRMC study, human-in-the-loop, or AI assistance is relevant.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Not applicable. This is a physical medical device, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- Not applicable / Implicit Ground Truth: For a ureteral stent, "ground truth" implicitly relates to the device's ability to safely and effectively facilitate urine drainage from the kidney to the bladder, as per its intended use and based on established engineering and medical principles. This is verified through comparisons to predicate devices, material testing, biocompatibility, and potentially preclinical/clinical performance data (though not detailed here).
8. The sample size for the training set
- Not applicable. This is a physical device, not an AI algorithm requiring a training set.
9. How the ground truth for the training set was established
- Not applicable. As above, no training set for an algorithm.
Summary of the Study Proving Device Meets Acceptance Criteria (based on 510(k) context):
The "study" proving the device meets its "acceptance criteria" (i.e., substantial equivalence) is the 510(k) Premarket Notification process itself.
- Nature of the Study: This is a regulatory submission where Boston Scientific Corporation provided documentation to the FDA to demonstrate that their "Modified Ureteral Stent" is substantially equivalent to legally marketed predicate devices. The performance characteristics of the modified device were compared to those of the predicate devices.
- Proof of Equivalence: The FDA's letter (K974541) confirms: "We have reviewed your Section 510(k) notification of intent to market the device and we have determined the device is substantially equivalent for the indications for use stated in the enclosure) to devices marketed in interstate commence prior to May 28, 1976..."
- What was "tested": While specific test results are not in the provided text, the 510(k) process would have included:
- Comparison of technological characteristics (e.g., materials, dimensions, design) to predicate devices.
- Performance testing (e.g., mechanical strength, durability, flow characteristics) to ensure the modified stent performs comparably to the predicate device.
- Biocompatibility testing of materials.
- Sterilization validation.
- Clinical data (if necessary, though often not for minor modifications to well-established devices like stents).
- Conclusion: The FDA's clearance (signified by the letter) acts as the "proof" that the device met the regulatory acceptance criterion of substantial equivalence.
§ 876.4620 Ureteral stent.
(a)
Identification. A ureteral stent is a tube-like implanted device that is inserted into the ureter to provide ureteral rigidity and allow the passage of urine. The device may have finger-like protrusions or hooked ends to keep the tube in place. It is used in the treatment of ureteral injuries and ureteral obstruction.(b)
Classification. Class II (performance standards).