(27 days)
The StrataMR II Valves and shunts are designed to provide continuous Cerebrospinal Fluid (CSF) flow from the ventricles of the brain into the right atrium of the heart or the peritoneal cavity. The design enables the physician to non-invasively adjust valve pressure/performance level pre-and post-implantation by using magnetic adjustment tools without the need of radiographic confirmation.
The StrataMR™ II adjustable valves are single-use implantable devices which provide a noninvasive method to address changing patient needs in the management of hydrocephalus. The valves and their associated catheters drain cerebrospinal fluid (CSF) from ventricles in the brain into the peritoneal cavity or the right atrium of the heart, where it is absorbed by the body. StrataMR™ II valve incorporates a ball and cone pressure valve in series with a normally closed siphon control mechanism. Flow control is achieved, and retrograde flow is prevented by combined resistance of the ball and cone and siphon control diaphragm. Pre- and postimplantation, the performance level of the valve can be modified by StrataMR™ Adjustment Tools: Locator tool, guider tool, indicator tool and adjustment tool cleared under K181622.
The provided text is a 510(k) Summary for the Medtronic StrataMR™ II Valves and Shunts, submitted to the FDA. It details performance testing to demonstrate substantial equivalence to a predicate device. However, this document does not describe a study involving an AI/Machine Learning device or a MRMC comparative effectiveness study involving human readers.
The document primarily focuses on bench testing and biocompatibility testing to show that changes in the device (specifically, the cap material and an additional tantalum marker) do not raise new safety or effectiveness concerns compared to the predicate device.
Therefore, many of the requested criteria, such as those related to AI model performance, human reader studies, ground truth establishment for training sets, and sample sizes for AI test sets, are not applicable to this submission.
Here's a breakdown of the information that can be extracted from the provided text, and where the requested information is not applicable:
1. A table of acceptance criteria and the reported device performance
The document provides a table titled "Performance Data – Bench" which outlines various tests, their summaries, and results. These results implicitly define the acceptance criteria, as all tests "met acceptance criteria."
| Test Category | Test Summary / Implicit Acceptance Criteria | Reported Performance (Results) |
|---|---|---|
| Resistance to Leakage | No leakage for 5 minutes with a differential pressure from inside to outside of 1 m H₂O. | "All valves met acceptance criteria, demonstrating that there are no concerns regarding valve integrity/leakage relative to the predicate device." |
| Reservoir Dome Needle Puncture | No leakage when repeatedly punctured with a non-coring needle under pressure. | "All valves met acceptance criteria, demonstrating that there are no concerns regarding valve integrity/leakage relative to the predicate device." |
| Dynamic Breaking Strength | No break, rupture or disconnection after 100,000 cycles at 1.0 ± 0.2 Hz (with tension applied in flow direction, leading to elongation of shunt of 10% or max force of 5 N). | (Implicitly "met acceptance criteria" as per the concluding statement: "StrataMR™ II valves and shunts met applicable pre-established acceptance criteria and raised no concerns regarding safety and effectiveness relative to the predicate device.") |
| Opening Pressure | Valve must show patency at a pressure that meets manufacturer's specifications. | "All valves met acceptance criteria, demonstrating that there are no concerns regarding valve opening pressure (patency)." |
| Pressure/Flow | Measured pressure must remain inside the manufacturer's specifications (tested per BS EN ISO 7197:2009). | (Implicitly "met acceptance criteria" as per the concluding statement) |
| Posture Effect | Difference between valve pressure at -50 cm hydrostatic pressure and 0 cm hydrostatic pressure must meet manufacturer's specifications. | (Implicitly "met acceptance criteria" as per the concluding statement) |
| Ability to withstand Overpressure | Valves must meet pre-established pressure/flow specifications after application of positive pressure of 1 m water (per BS EN ISO 7197:2009). | "All valves met acceptance criteria, demonstrating that there are no concerns regarding pressure/flow performance relative to the predicate device." |
| Bursting Pressure | Valves must meet pre-established pressure/flow specifications after application of positive pressure of 2 m water (per BS EN ISO 7197:2009). | "All valves met acceptance criteria, demonstrating that there are no concerns regarding pressure/flow performance relative to the predicate device." |
| Long Term Stability | Valves must maintain pre-established pressure/flow specifications after 28 days in a water bath at 37℃ ± 5° while pumping water through the valves at an average flow rate of 20 mL/h. | (Implicitly "met acceptance criteria" as per the concluding statement) |
| Flushing Capacity | Flushing volume produced from valve reservoir compressions must meet acceptance criteria. | "All valves met acceptance criteria, demonstrating that there are no concerns regarding reservoir volume relative to the predicate device." |
| Identification of Shunts in vivo | Valve identification markers must be visible, and valve setting must be readable in X-ray images. | "All valves met acceptance criteria, demonstrating that there are no concerns regarding identification of the valve via X-ray relative to the predicate device." |
| Post-MRI Functional Testing | After MRI exposure, valves must: (1) maintain pre-conditioning pressure setting, (2) be able to be read and adjusted, and (3) meet pre-established pressure/flow specifications. | "All valves met acceptance criteria, demonstrating that there are no concerns regarding performance after MRI exposure relative to the predicate device." |
| MRI Safety Information | Device must be MR conditional and demonstrate no MRI safety concerns when scanned according to MR conditions specified in labeling (testing per ASTM F2052-15, F2213-06, F2182-11a, F2119-07). | "Test results demonstrated that StrataMR™ II valves are MR conditional and that there are not MRI safety concerns relative to the predicate device when scanned according to the MR conditions specified in the labeling." |
Biocompatibility Testing:
| Test | Test Method Summary / Implicit Acceptance Criteria | Results |
|---|---|---|
| Cytotoxicity - MEM Elution | Cell culture treated with test sample exhibited no signs of toxicity (Grade 0). | Non-cytotoxic |
| Irritation - Intracutaneous study in rabbits | Animals treated with test sample exhibited no dermal reactions (Grade 0). | Non-irritant |
| Sensitization - Guinea Pig Maximization | Animals treated with test sample exhibited no dermal reactions. | Non-sensitizer |
| Systemic toxicity - Acute systemic toxicity study in mice | Animals treated with test sample exhibited no mortality or evidence of systemic toxicity. | Non-toxic |
| Material Mediated Pyrogenicity - USP Rabbit Pyrogen Study | Individual animals treated with test sample exhibited no temperature rise above 0.5°C. | Non-pyrogenic |
| Genotoxicity / Carcinogenicity | Test article did not show a significantly greater biological reaction than the controls. | Non-mutagenic |
| Implantation | Test did not show a significantly greater biological reaction than the control (Grade 0 - no reaction). | Non-toxic |
| Hemocompatibility | Test article exhibited no hemolysis and was within the control values. | Non-hemolytic |
2. Sample sizes used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
This information is not applicable as the provided text describes bench and biocompatibility testing of a physical medical device, not an AI/ML system tested on a data set. The sample size for each bench or biocompatibility test would refer to the number of physical device units or animal subjects used, which is not explicitly stated for individual tests but is inherent in standard device testing protocols. No provenance for "data" in the context of AI is relevant here.
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 is not applicable. Ground truth, in the context of AI, refers to expert-labeled data for model training/testing. This document describes physical device testing against engineering and biological standards, not AI-based image analysis or diagnosis.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
This is not applicable. Adjudication methods are used to establish ground truth from multiple human experts for AI model evaluation. Not relevant to this device submission.
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, a MRMC comparative effectiveness study was not done. This submission is for a physical medical device (shunt and valve), not an AI-assisted diagnostic tool.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This is not applicable. This describes a physical device, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
For the bench and biocompatibility tests, the "ground truth" or standard for acceptance is based on:
- Pre-established engineering specifications: For pressure, flow, strength, and durability tests.
- International standards (e.g., BS EN ISO 7197:2009, ASTM F2052-15, F2213-06, F2182-11a, F2119-07): For performance and MRI safety.
- Biocompatibility standards (e.g., ISO 10993-1): For biological safety tests in vitro and in vivo.
There is no "expert consensus" or "pathology" in the AI sense.
8. The sample size for the training set
This is not applicable. There is no "training set" as this is not an AI/ML device.
9. How the ground truth for the training set was established
This is not applicable.
§ 882.5550 Central nervous system fluid shunt and components.
(a)
Identification. A central nervous system fluid shunt is a device or combination of devices used to divert fluid from the brain or other part of the central nervous system to an internal delivery site or an external receptacle for the purpose of relieving elevated intracranial pressure or fluid volume (e.g., due to hydrocephalus). Components of a central nervous system shunt include catheters, valved catheters, valves, connectors, and other accessory components intended to facilitate use of the shunt or evaluation of a patient with a shunt.(b)
Classification. Class II (performance standards).