(28 days)
The Midas Rex MR8 Depth Stop attachment and tools are indicated for the incision, cutting, removing, and drilling of soft and hard tissue during cranial surgical procedures with the intent to create a hole through the cranium to allow surgeons access to desired surgical locations and/or to facilitate insertion, placement of other surgical devices during such procedures.
The Midas Rex MR8 Depth Stop attachment and tools are intended to create a cranial access hole of a known diameter and depth.
This document (K213454) is a 510(k) premarket notification for a medical device and, as such, does not contain the detailed information necessary to answer all aspects of your request regarding acceptance criteria and a study that proves the device meets those criteria.
Specifically, this submission focuses on demonstrating substantial equivalence to a predicate device, rather than providing a comprehensive study protocol and results for a new device's performance against specific acceptance criteria. The document states that "The changes from the predicate, do not raise any new issues of safety and effectiveness" and that "The following testing was conducted to demonstrate that the modifications to the subject devices are as safe and effective as the predicate." This implies that the focus was on validating that the changes did not degrade performance, and the existing predicate device's performance serves as the benchmark.
Therefore, many of the questions asked cannot be directly answered from the provided text.
Here's an attempt to extract what is available and explain what is missing:
1. A table of acceptance criteria and the reported device performance
The document does not provide a table of acceptance criteria and reported device performance in the way you've requested. Instead, it describes a comparison to a predicate device to demonstrate substantial equivalence. The "performance" is primarily implied by the claim that the technological characteristics are similar and that conducted testing (Product Life Verification, Summative Validation, Biocompatibility Testing) supports the functionality, integrity, and safety and effectiveness for its intended use, making it "as safe and effective as the predicate."
The closest thing to "acceptance criteria" discussed are the aspects compared to the predicate, as shown in the table on pages 5-6. However, these are comparative features, not quantified performance criteria with acceptance thresholds.
| Feature | Subject Device (Midas Rex™ MR8™ Depth Stop System) Performance (as presented) | Acceptance Criteria (implied/compared to predicate) |
|---|---|---|
| Sponsorship | Medtronic Powered Surgical Solutions | Identical to Predicate |
| Product Code | HBE | Identical to Predicate (HBE) |
| Drill System | Pneumatic, Electric | Identical to Predicate |
| Operating Principle | (Not explicitly stated, assumed to be rotational drilling) | Identical to Predicate |
| Intended Use | Create a cranial access hole of a known diameter and depth. | Identical to Predicate |
| Indications for Use | Incision, cutting, removing, and drilling of soft and hard tissue during cranial surgical procedures to create a hole through the cranium. | Identical to Predicate |
| System Components | Electric Handpieces, Pneumatic Handpieces, Attachments, Surgical Dissecting Tools | Identical to Predicate |
| Patient Contacting Components | Attachments, Surgical Dissecting Tools | Identical to Predicate |
| Attachment Materials | Stainless Steel, Aluminum, Ceramic, Phenolic, Epoxy, Chrome Coated Brass, Polymeric | Identical to Predicate |
| Attachment Configuration | Straight, Variable | Identical to Predicate |
| Attachment Tube Length | 12.8cm (retracted), 14.5cm (exposed) | Equivalent to Predicate (13.7cm/14.8cm); argument made that difference does not impact performance or safety. |
| Sterilization Method – Reusable | Steam | Identical to Predicate |
| Surgical Dissecting Tool Materials | Tool Steel | Identical to Predicate |
| Dissecting Tool Tip Style | Twist Drill | Equivalent to Predicate (Twist Drill); minor modifications without impact on safety/performance. |
| Dissecting Tool Overall Length | 17-22cm | Identical to Predicate |
| Dissecting Tool Head Diameter | 2.1 – 7.5 mm | Identical to Predicate |
| Packaging – Sterile Dissecting Tools | Individually packaged in clear plastic capped tube within polypoly pouch. Tube cap is blue. | Equivalent to Predicate; predicate cap is yellow, otherwise identical. |
| Sterilization Method – Single Use | Gamma with minimum radiation dose of 25 kGy | Identical to Predicate |
| Shelf Life – Dissecting Tools | 5 Years | Identical to Predicate |
| Extended Depth Setting | Up to 20mm (new feature) | Not applicable as a direct comparison to predicate, but implied acceptance would be that this extension also functions safely and effectively. (This implies a new "performance" aspect not listed in the main comparison table). |
| New Task in User Workflow | (Not detailed) | Not applicable as a direct comparison. Implied acceptance is that this new task is also safe and effective. |
2. Sample size used for the test set and the data provenance
The document mentions "Product Life Verification," "Summative Validation," and "Biocompatibility Testing." However, it does not specify sample sizes for any of these tests, nor does it provide information on the data provenance (e.g., country of origin, retrospective or prospective). Given the nature of a 510(k) for a mechanical device modification, these would likely be engineering and bench testing, not clinical studies in the typical sense.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
This information is not provided in the document. The testing described (Product Life, Summative Validation, Biocompatibility) are typically engineering validation tests, not clinical studies requiring expert ground truth in the context of diagnostic AI.
4. Adjudication method for the test set
This information is not provided. As above, the described testing types do not typically involve adjudication methods for "ground truth" derived from 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
No MRMC study was done or mentioned. This device is a surgical drill accessory, not an AI software/diagnostic device.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Not applicable. This device is a mechanical surgical tool component, not an algorithm.
7. The type of ground truth used
The concept of "ground truth" in the way it's typically applied to AI or diagnostic studies (expert consensus, pathology, outcomes data) is not relevant or discussed for this type of mechanical device submission. The "ground truth" for this device would be established by engineering specifications, material properties, and mechanical performance tests.
8. The sample size for the training set
Not applicable. This is a mechanical device, not an AI/machine learning product that requires a training set.
9. How the ground truth for the training set was established
Not applicable. As above, this is a mechanical device.
Summary of Findings from the Document:
The K213454 submission demonstrates substantial equivalence primarily by:
- Comparing the subject device's features and intended use to a legally marketed predicate device (K191597).
- Highlighting that the differences are minor (e.g., extended depth setting, minor tool head geometry, new user task, compatibility with MR8 system) and do not raise new safety or effectiveness concerns.
- Stating that risk management (ISO 14971:2019) was conducted and found no new risks.
- Reporting that specific engineering tests were conducted: "Product Life Verification," "Summative Validation," and "Biocompatibility Testing," which "demonstrate that the functionality, integrity, and safety and effectiveness of the subject devices are sufficient for their intended use."
The document's purpose is to show that the modified device is "as safe and effective" as the already cleared predicate, rather than to establish new, distinct performance criteria and demonstrate achievement of those from scratch.
§ 882.4310 Powered simple cranial drills, burrs, trephines, and their accessories.
(a)
Identification. Powered simple cranial drills, burrs, trephines, and their accessories are bone cutting and drilling instruments used on a patient's skull. The instruments are used with a power source but do not have a clutch mechanism to disengage the tip after penetrating the skull.(b)
Classification. Class II (performance standards).