(29 days)
MEMO 4D device is intended for correction of mitral insufficiencies or steno-insufficiencies.
The use of the Memo 4D device is indicated for correction of congenital insufficiencies with dilatation and deformation of the mitral annulus. Type I insufficiencies, with no manifest lesions in the subvalvular apparatus, can be treated with the implant of the annuloplasty ring on its own. For type II insufficiencies, characterised by valve prolapse sustained by elongation/ breakage of the chordae tendineae and papillary muscles, and type III insufficiencies, characterised by partially immobilised leaflets due to the fusion/hypertrophy of the chordae tendineae, the device implantation must be accompanied by corrective valvuloplasty.
Like its predicate device (the MEMO 3D ReChord Semirigid Annuloplasty Ring, K142221), the MEMO 4D Semirigid Annuloplasty Ring is supplied as a sterile, non-pyrogenic ring pre-mounted on a disposable holder.
Both the predicate and subject device are manufactured by embedding a superelastic metallic alloy inner core with medical grade silicone.
The resulting silicone sheath around the inner core is then encased within a tubular knitted fabric coated with a thin layer of turbostratic carbon (Carbofilm™). The fabric is then sewn along its length with a Carbofilm™ coated polyester thread.
Both the predicate and subject device feature a fully removable system (i.e., the ReChord System) in the posterior curve of the annuloplasty ring, composed by a series of loops made by a single piece of yellow surgical thread retained in place by a single piece of blue surgical thread.
The ReChord System is designed to provide a temporary reference element to facilitate the sizing of the artificial chord length at the annular plane level when performing replacement of mitral chordae tendineae in concomitance with the implant of the annuloplasty ring.
The following changes were implemented:
The MEMO 4D is available in two new sizes: 40mm and 42mm.
The MEMO 4D features a larger silicone filler layer in the outer portion of the ring, intended to further facilitate ring suturing to the annulus.
A re-shaping of the MEMO 4D annuloplasty ring was implemented for sizes 34 to 42 mm. These sizes maintain the same core cross-sectional diameter and commissure-to-commissure dimension as the predicate MEMO 3D ReChord, but feature a gradual increase of the ring antero-posterior dimension and an out-of-plane "saddle" shape in the anterior ring portion. The ring re-shaping creates a differentiated design for the MEMO 4D with respect to the MEMO 3D ReChord. The design includes a rounder shaped implant to accommodate cases of excess leaflet tissue which may be indicative of degenerative mitral disease.
Minor design changes to the disposable holder to adapt to the modified ring shape and a new injection molding supplier for the holder were also introduced. The MEMO 4D packaging system was redesigned, introducing a double nested blister to replace the polysulfone containers used for the predicate MEMO 3D ReChord.
A complete set of accessories is available separately to properly size the annulus and implant the MEMO 4D annuloplasty ring.
The provided text is a 510(k) Summary for the MEMO 4D Semirigid Annuloplasty Ring, which is a premarket notification to the FDA to demonstrate that the device is substantially equivalent to a predicate device already on the market. In this context, "acceptance criteria" and "device performance" don't refer to typical clinical performance metrics for a diagnostic AI device, but rather to the engineering and design characteristics that demonstrate equivalence to the predicate device and ensure safety and efficacy.
Therefore, the requested information elements (1-9) need to be interpreted in the context of a medical device submission based on substantial equivalence, rather than a study validating an AI diagnostic algorithm.
Here's an analysis based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly present a table of "acceptance criteria" with corresponding "device performance" results in the manner one might expect for a diagnostic AI study. Instead, it details the verification and validation (V&V) testing performed to demonstrate that the MEMO 4D device maintains the safety and effectiveness profile of its predicate device, the MEMO 3D ReChord Semirigid Annuloplasty Ring (K142221).
The "acceptance criteria" are implied to be that the MEMO 4D performs comparably to the predicate or meets established engineering standards for such devices. The "reported device performance" is the successful completion of the non-clinical tests, indicating that the design changes did not negatively impact safety or efficacy.
| Acceptance Criteria (Implied) | Reported Device Performance (Summary of Test Findings) |
|---|---|
| Maintain structural integrity and mechanical properties under stress. | Computational stress analysis (FEA) and tensile strength testing completed successfully. |
| Maintain durability and resist fatigue. | Fatigue and durability testing completed successfully. |
| Ensure secure attachment and removal of the ReChord System. | Extraction tests for the ReChord System threads and disposable holder completed successfully. |
| Demonstrate biocompatibility. | Biocompatibility testing completed successfully. |
| Be compatible with MRI. | MRI compatibility testing completed successfully. |
| Maintain packaging integrity during distribution and over shelf-life. | Simulated distribution testing and package integrity and microbial barrier test after accelerated aging completed successfully. |
| Function as intended during surgical use. | Simulated use testing completed successfully. |
| Maintain the same material and operating principles as the predicate device. | The MEMO 4D annuloplasty ring is identical to the predicate MEMO 3D ReChord device in implanted materials, device operating principle, and mechanism of action. |
| Sterilization process is effective and maintained. | The MEMO 4D is steam-sterilized using the same process in the same facility with respect to the predicate device. |
| Packaging materials are suitable for maintaining sterility. | Materials used for MEMO 4D packaging are widely used for similar applications, and the sterile barrier has been qualified to maintain device sterility over its stated shelf-life. |
Previous testing on the predicate device for suture pull-out, corrosion resistance, and long-term biocompatibility remains valid for MEMO 4D due to similar materials, design, and manufacturing technologies.
2. Sample Size Used for the Test Set and the Data Provenance
The document does not specify a "test set sample size" in terms of clinical cases or patient data, as this was a non-clinical submission. The "test set" refers to the physical devices and materials used in the various non-clinical engineering and biological tests (e.g., computational models for FEA, physical rings for tensile strength, fatigue, and extraction tests, materials for biocompatibility, etc.).
- Sample Size: Not explicitly stated for each test, but typically, these tests involve a sufficient number of samples as per recognized engineering standards (e.g., ISO, ASTM) to provide statistical confidence.
- Data Provenance: The testing was conducted by Sorin Group Italia S.r.l. and appears to be internal validation data. The country of origin for the testing would be Italy, where Sorin Group Italia S.r.l. is located. The nature of the data is retrospective in the sense that it's laboratory-generated data for product validation, not prospective clinical trial data.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts
This is not applicable as there was no clinical "test set" requiring expert ground truth in the traditional sense. The "ground truth" for non-clinical performance relies on established engineering principles, materials science, and regulatory standards. The experts involved would be engineers, material scientists, and regulatory specialists within Sorin Group Italia S.r.l., along with those at the FDA reviewing the submission. Their qualifications are inherent in their professional roles, but not detailed here.
4. Adjudication Method for the Test Set
This is not applicable. Adjudication methods like "2+1" or "3+1" are used in clinical studies, particularly for diagnostic accuracy, where multiple readers interpret cases and a consensus is reached. The performance data presented here is from non-clinical engineering and material property tests.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC comparative effectiveness study was not done. The document explicitly states: "No clinical testing was conducted in support of the MEMO 4D Semirigid Annuloplasty Ring, as the indications for use are equivalent to those of its predicate device MEMO 3D ReChord." Therefore, there is no effect size for human readers improving with or without AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
This question is not applicable to a physical medical device like an annuloplasty ring. This question is relevant for AI algorithms. The MEMO 4D is an implantable device, not an AI algorithm.
7. The Type of Ground Truth Used
The "ground truth" for this submission is based on:
- Engineering Standards and Specifications: For mechanical properties, durability, material compatibility, and packaging integrity.
- Biocompatibility Standards: In vitro and potentially in vivo (from predicate) tests to ensure the materials are safe for implantation.
- Regulatory Precedent: The predicate device (MEMO 3D ReChord) having a proven safety and efficacy record on the market established the "ground truth" for the device type, allowing for substantial equivalence without new clinical data.
8. The Sample Size for the Training Set
This is not applicable. There is no "training set" in the context of an AI algorithm or a machine learning model for this medical device submission. The device is a physical product designed and manufactured based on established engineering principles, not trained on data.
9. How the Ground Truth for the Training Set Was Established
This is not applicable as there is no training set for an AI algorithm. The device's design and manufacturing rely on established medical device development processes and regulatory compliance rather than machine learning "ground truth" establishment.
§ 870.3800 Annuloplasty ring.
(a)
Identification. An annuloplasty ring is a rigid or flexible ring implanted around the mitral or tricuspid heart valve for reconstructive treatment of valvular insufficiency.(b)
Classification. Class II (special controls). The special control for this device is the FDA guidance document entitled “Guidance for Annuloplasty Rings 510(k) Submissions.”