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The Medtronic StrataMR™ Valves and Shunts are designed to provide continuous cerebrospinal fluid (CSF) flow from the ventricles of the brain into the right atrium of the peritoneal cavity. The design enables the physician to noninvasively adjust valve pressure/performance level pre- and post-implantation by using magnetic adjustment tools without the need for radiographic confirmation.

Device Description

The Medtronic StrataMR™ valves are implantable adjustable valves for the management of hydrocephalus. The valves and their associated catheters drain Cerebrospinal Fluid (CSF) from the ventricles in the brain into the peritoneal cavity or the right atrium of the heart, where it is absorbed by the body. The Medtronic StrataMR™ 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. Before and after implantation, the pressure/flow characteristics of the Medtronic StrataMR™ valve can by modified by means of a magnetic adjustment tool.

AI/ML Overview

The provided document describes the Medtronic StrataMR™ Valves and Shunts and details the testing performed to demonstrate its substantial equivalence to a predicate device (Medtronic PS Medical Strata Type Valve (K060681)). The information focuses on bench testing and biocompatibility testing, rather than a study involving AI performance or human reader studies.

Therefore, many of the requested criteria regarding AI performance, human reader studies, and large-scale data sets (like training or test sets for AI) are not applicable to this device's submission and the testing described. The device is a physical medical device (a shunt valve), not a software or AI-driven diagnostic tool.

Here's an analysis of the provided text in relation to your questions, highlighting what is present and what is absent/not applicable:

Analysis of Acceptance Criteria and Proving Device Performance

The core of the submission relies on demonstrating substantial equivalence to a previously cleared predicate device. This means the acceptance criteria are largely tied to meeting performance benchmarks that are comparable to or better than the predicate, as well as showing the new design changes (primarily for improved MR resistance) do not introduce new safety or efficacy concerns.

1. Table of Acceptance Criteria and Reported Device Performance

The document provides a summary of bench tests with their methods and results. The "acceptance criteria" are implied by the "Results" column stating "All valves met acceptance criteria," or by explicitly stating values (e.g., for biocompatibility).

Test	Test Method Summary	Acceptance Criteria Implied/Stated	Reported Device Performance
Bench Testing
Resistance to leakage	Measured using air. Required no leakage for 5 minutes with a differential pressure of 1 m H2O.	No leakage for 5 minutes with 1 m H2O differential pressure.	All valves met acceptance criteria, demonstrating no concerns regarding valve integrity/leakage relative to the predicate device.
Reservoir dome needle puncture	Show no leakage when repeatedly punctured with a non-coring needle under pressure.	No leakage after repeated punctures.	Results not explicitly stated as "met acceptance criteria" in table, but overall conclusion states "all cases, the results of bench testing met applicable pre-established acceptance criteria."
Dynamic breaking strength	Tension applied in flow direction (10% elongation or 5 N max force). No break, rupture, or disconnection after 100,000 cycles at 1.0 ± 0.2 Hz.	No break, rupture, or disconnection after 100,000 cycles.	Results not explicitly stated as "met acceptance criteria" in table, but overall conclusion states "all cases, the results of bench testing met applicable pre-established acceptance criteria."
Pressure/flow	Tested according to ISO 7197:2006. Measured pressure to remain inside manufacturer's specifications.	Measured pressure must be within manufacturer's specifications.	Results not explicitly stated as "met acceptance criteria" in table, but overall conclusion states "all cases, the results of bench testing met applicable pre-established acceptance criteria."
Siphon control device casing effect	Compared valve pressure at -50 cm hydrostatic pressure with 0 cm. Difference to meet manufacturer's specifications.	Difference in pressure must meet manufacturer's specifications.	Results not explicitly stated as "met acceptance criteria" in table, but overall conclusion states "all cases, the results of bench testing met applicable pre-established acceptance criteria."
Ability to withstand overpressure	After application of positive pressure (1 m water per ISO 7197:2006), valves to meet pre-established pressure/flow specifications.	Valves must meet pre-established pressure/flow specifications.	All valves met acceptance criteria, demonstrating no concerns regarding pressure/flow performance relative to the predicate device.
Bursting pressure	After application of positive pressure (2 m water per ISO 7197:2006), valves to meet pre-established pressure/flow specifications.	Valves must meet pre-established pressure/flow specifications.	Results not explicitly stated as "met acceptance criteria" in table, but overall conclusion states "all cases, the results of bench testing met applicable pre-established acceptance criteria."
Long term stability	Valves in water bath (37°C ± 5) with pumping water (20 mL/h) for 28 days. Valves to maintain pre-established pressure/flow specifications.	Valves must maintain pre-established pressure/flow specifications after 28 days.	Results not explicitly stated as "met acceptance criteria" in table, but overall conclusion states "all cases, the results of bench testing met applicable pre-established acceptance criteria."
Identification of shunts in vivo	X-ray imaging. Valve identification markers must be visible and valve setting readable.	Valve identification markers visible and valve setting readable in X-ray images.	All valves met acceptance criteria, demonstrating no concerns regarding identification of the valve via X-ray relative to the predicate device.
Post-MRI functional testing	Exposed to multiple MRI exposures in clinically relevant orientation. Valves to maintain pre-conditioning pressure setting, be readable and adjustable, and meet pre-established pressure/flow specifications.	Maintain pre-conditioning pressure setting, be readable/adjustable, and meet pre-established pressure/flow specifications after MRI.	All valves met acceptance criteria, demonstrating no concerns regarding valve performance after MRI exposure relative to the predicate device.
Design validation testing	Surgeon evaluators read and adjusted valves, pre- and post-implantation in cadavers.	Evaluators must be able to successfully read and adjust valves.	In all cases evaluators were able to successfully read and adjust the valves, demonstrating no concerns related to valve readability/adjustability relative to the predicate device.
MRI safety testing	Magnetically induced displacement force (ASTM F2052-15), magnetically induced torque (ASTM F2213-06), radio frequency induced heating (ASTM F2182-11a), image artifact testing (ASTM F2119-07).	Test results demonstrated MR conditional and no MRI safety concerns relative to predicate when scanned per labeling conditions.	Test results demonstrated that StrataMR 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 (Shunt)
Cytotoxicity	ISO MEM Elution. Incubated at 37°C for 48 hr. Examined microscopically for abnormal cell morphology and cellular degeneration.	Extract must show no evidence of causing cell lysis or toxicity (score = 0). Test article must meet requirements (score ≤ 2).	Pass. Extract showed no evidence of causing cell lysis or toxicity (score = 0). Test article met requirements of the test (score ≤ 2).
Irritation	ISO Intracutaneous Study in Rabbits. Extracted separately in saline and sesame oil. Observations for erythema and edema at 24, 48, and 72 hr.	Scores ≤ 1.0.	Pass. Scores = 0.0 for saline and 0.1 for oil. Extracts met requirements of the test (score of 1.0 or less).
Acute systemic toxicity	ISO Systemic Toxicity Study in Mice. Extracted separately in saline and sesame oil. Observations for signs of systemic toxicity at 0, 4, 24, 48, and 72 hrs.	No mortality or evidence of systemic toxicity.	Pass. No mortality or evidence of systemic toxicity from extracts. Extracts met requirements of the test.
Material-mediated pyrogenicity study	USP Material-Mediated Pyrogen Study. Extracted in saline. Rectal temperatures measured prior to injection and at 30 min intervals between 1 and 3 hours.	Total temperature rise during 3 hr period ≤ 0.5°C (max rise of 0.2°, 0.2°, and 0.1°C for three rabbits). No single animal showed rise of ≥0.5°C and total temp rise < 3.3°C. Test article judged nonpyrogenic.	Pass. Total temperature rise during 3 hr period was 0.5°C (max rise of 0.2°, 0.2°, and 0.1°C for three rabbits). Test article judged nonpyrogenic. Total temp rise within acceptable USP limits.
Sensitization	ISO Guinea Pig Maximization Test. Extracted separately in saline and sesame oil. Dermal reactions scored at 24 and 48 hr.	Not a sensitizer (grade = 0). No evidence of causing delayed dermal contact sensitization.	Pass. Test article not a sensitizer (grade = 0 for saline and oil). Extracts showed no evidence of causing delayed dermal contact sensitization.
Genotoxicity	Bacterial Reverse Mutation Study (AMES). Mouse Lymphoma Assay. Mouse Peripheral Blood Micronucleus Study. Evaluations for mutagenicity and cytogenetic damage.	Nonmutagenic (e.g., no ≥ 2-fold increase in mean number of revertants for specified strains; no ≥ 2-fold increase in mean mutant frequency) and no induction of micronuclei.	Pass. Both extracts nonmutagenic to all test strains. Test article did not induce micronuclei in mice. No significant increase in % micronucleated reticulocytes.
Subchronic/subacute toxicity	ISO Four Week Toxicity Study in Rat, Repeated Parenteral Administration. Daily IV or intraperitoneal injections. Observations for general health, detailed health exams, body weight, blood samples, necropsy.	No systemic toxicity in rats. Clinical observations, body weights, hematology, clinical chemistry, necropsy results, organ weights and ratios similar between test and control groups. No microscopic changes due to test article.	Pass. Extract did not produce systemic toxicity in rats. Clinical observations, body weights, hematology, clinical chemistry, necropsy results, organ weights, organ/body weight ratios, and organ/brain weight ratios were similar between test and control groups. No microscopic changes due to test article.
Implantation	ISO Subcutaneous Implantation Study in Rabbits, 13 Weeks. Implant sites examined macroscopically and microscopically.	Macroscopic reaction not significant compared to negative control. Microscopic evaluation score ≤ 2.9 (nonirritant).	Pass. Macroscopic reaction not significant compared to negative control article. Microscopic evaluation score = 2.3 compared to control. Test article classified as nonirritant compared to negative control (score = 0.0-2.9).
Biocompatibility Testing (Adjustment Tools Components)
Cytotoxicity	ISO MEM Elution.	Extracts show no evidence of causing cell lysis or toxicity (score = 0). Test articles meet requirements (score ≤ 2).	Pass. Extracts showed no evidence of causing cell lysis or toxicity (scores = 0). Test articles met requirements of the test (score ≤ 2).
Irritation	ISO Intracutaneous Study in Rabbits.	Scores ≤ 1.0.	Pass. Scores = 0.0 for saline and 0.2 for oil. Extracts met requirements of the test (score of 1.0 or less).
Acute systemic toxicity	Extracted in saline and sesame oil. Observations for signs of systemic toxicity.	No mortality or evidence of systemic toxicity.	No mortality or evidence of systemic toxicity from extracts. Extracts met requirements of the test.
Sensitization	ISO Guinea Pig Maximization Test.	Not a sensitizer (grade = 0). No evidence of causing delayed dermal contact sensitization.	Pass. Test article not a sensitizer (grade = 0 for saline and oil). Extracts showed no evidence of causing delayed dermal contact sensitization.

2. Sample size used for the test set and the data provenance

Sample Size: The document does not explicitly state the number of units tested for each bench test, but it consistently refers to "all valves" meeting acceptance criteria, implying a representative sample was used. For biocompatibility, specific numbers of animals (e.g., rabbits, mice, guinea pigs) are implied by the test methods (e.g., "triplicate" for cytotoxicity, "in rabbits/mice/guinea pigs" for others).
Data Provenance: The data is from "Bench Testing" and "Biocompatibility Testing" performed by Medtronic. The studies appear to be prospective bench and animal studies conducted in a lab setting, not retrospective or prospective human clinical data. The country of origin of the data is implied to be where Medtronic's testing facilities are located (likely USA or a facility adhering to international standards).

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

Experts: For "Design validation testing," it states "Surgeon evaluators read and adjusted valves, both prior to and after implantation in cadavers."
Qualifications: "Surgeon evaluators" are mentioned. Their specific qualifications (e.g., years of experience, subspecialty) are not detailed in this summary. This is not a diagnostic device where "ground truth" in the clinical sense (e.g., presence of disease based on expert consensus) would be established by radiologists/pathologists. Instead, it's about the functionality and adjustability of a physical device by its intended users.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

Not Applicable: This type of adjudication method is typically used in clinical studies involving interpretation of medical images or patient data, especially when establishing ground truth for AI algorithms. For bench testing of a physical device, this concept does not apply. The "Design validation testing" involved surgeons directly interacting with the device, and the "results" refer to their successful manipulation of the device.

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 product is a physical medical device (a shunt valve), not an AI-assisted diagnostic tool. No MRMC study was performed, and thus no effect size related to AI assistance for human readers is available or relevant.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

Not Applicable: As mentioned, this is a physical device, not an algorithm. Therefore, no standalone algorithm performance testing was conducted.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

For the bench testing, the "ground truth" is defined by the objective, quantifiable specifications (e.g., no leakage, specific pressure/flow ranges, presence of visible markers, successful adjustment) as determined by established engineering and quality control standards (e.g., ISO, ASTM, manufacturer's specifications).
For the design validation testing, the "ground truth" for adjustability/readability was established through direct interaction by medical professionals ("surgeon evaluators") performing the actions the device is designed for, likely against a checklist of successful outcomes.
For biocompatibility testing, the "ground truth" is established through standardized biological assays and animal studies, with results compared to pre-defined acceptable biological responses (e.g., no cytotoxicity, non-irritating, non-sensitizing, non-toxic).

8. The sample size for the training set

Not Applicable: This device does not involve machine learning or AI, so there is no training set in the AI sense.

9. How the ground truth for the training set was established

Not Applicable: As there is no AI training set, this question is not relevant.

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