(30 days)
The SmartTwist™ MRII Hand Drill and accessories are intended to provide access through the skull for ventriculostomy or other neurological procedures, such as biopsy or catheter placement, in or near an MR scanner of 3T maximum strength. The SmartTwist MRII Hand Drill and accessories are intended to be used only when the scanner is not performing a scan. The SmartTwist MRII Hand Drill is intended for single use only.
The SmartTwist MRII Hand Drill is a hand held manual drill with a 3:1 gear ration. It is intended for use with the drill kit accessory kits SmartTip Drill Kits for a 3.2mm, 4.5mm and 6.0mm drill bit, with lancet, depth stop and ruler.
The provided document is a 510(k) summary for the SmartTwist™ MRII Hand Drill, SmartTip™ MRII Drill Bit Kit, 4.5mm, 6.0mm, seeking substantial equivalence to the predicate device, the MRII Cranial Drill, K122456.
The document describes the performance data and acceptance criteria in terms of demonstrating substantial equivalence, rather than a traditional study with strict acceptance criteria and performance metrics for an AI/software device. This is a physical medical device, specifically a hand drill and drill bit kits.
Here's an breakdown based on the provided text, focusing on how the device meets "acceptance criteria" through comparison with its predicate:
1. Table of Acceptance Criteria and Reported Device Performance
For this type of device (manual surgical drill), "acceptance criteria" are not reported as specific performance metrics (e.g., accuracy, sensitivity) like for diagnostics or AI. Instead, the acceptance is based on demonstrating substantial equivalence to a previously cleared predicate device, meaning it has the same intended use, similar technological characteristics, and raises no new questions of safety or effectiveness. The performance is therefore reported in terms of equivalence to the predicate and compliance with recognized standards.
| Feature / Criteria (Implied by Substantial Equivalence) | Predicate Device (MRII Cranial Drill) | Subject Device (SmartTwist MRII Hand Drill w/ 4.5mm & 6.0mm Kits) | Acceptance/Performance (Comparison/Result) |
|---|---|---|---|
| Intended Use | Same | Same | Meets: Intended to provide access through the skull for neurological procedures in/near a 3T MR scanner, used when scanner not performing a scan, single use only. |
| Technological Characteristics | Similar (manual drill, specific materials, adjustable depth guard, sterilization method) | Similar (manual drill, specific materials, adjustable depth guard, sterilization method) | Meets: Same classification, product code, environment, sterilization, drill bit material (316L SST), and adjustable depth guard. Main difference is additional drill bit sizes. |
| Principles of Operation | Similar | Similar | Meets: Operates as a manual hand drill with gear ratio to facilitate drilling. |
| Safety & Effectiveness | Established (previously cleared predicate) | No new issues raised | Meets: "The minor technological differences... raise no new issues of safety and effectiveness." Performance testing "established the equivalence" and "functions as intended and performs comparably." Risk analysis performed with mitigation of all identified risks. |
| Biocompatibility | Complies with AAMI/ANSI/ISO 10993-1 | Complies with AAMI/ANSI/ISO 10993-1 | Meets: Stated compliance. "No new materials have been introduced so the safety testing with the MRI Cranial Drill Kits is fully applicable." |
| Sterilization Efficacy | Complies with ANSI/AAMI/ISO 1135-1 | Complies with ANSI/AAMI/ISO 1135-1 | Meets: Stated compliance for EO 10-6 SAL sterilization. |
| MRI Safety (Magnetically Induced Displacement Force) | Complies with ASTM F2052-05e1 | Complies with ASTM F2052-05e1 | Meets: Stated compliance. |
Key Differences from Predicate (and how they meet criteria):
- Drill Bit Sizes: Predicate: 2.0mm, 3.2mm. Subject Device: 4.5mm, 6.0mm (addition of two new sizes).
- Acceptance: This "addition of drill sizes is at the request of clinicians" and is deemed "equivalent in intended use, technological characteristics and principles of operation to the predicate MRII Cranial Drill."
- Packaging: Slight variation (Predicate: Drill is CSR Wrap in Tyvek Peel Pouch, Kit is Sterile, inside tray with Tyvek Lid and external Tyvek Pouch. Subject: Kit: Sterile, inside tray with Tyvek Lid and external Tyvek Pouch).
- Acceptance: Not highlighted as a safety concern; assumes equivalent sterile barrier properties.
2. Sample Size Used for the Test Set and the Data Provenance
This document does not describe a clinical study in the sense of a test set with patient data for determining diagnostic accuracy or treatment outcomes. Instead, it refers to "Performance Data" from "Design Verification" and "Risk Analysis."
- Sample Size: Not specified in terms of patient data or number of devices tested in a formal sample size calculation. The verification likely involved destructive and non-destructive testing on a representative number of devices/components to ensure manufacturing quality and performance.
- Data Provenance: Not applicable in the context of patient data. The "performance data" would originate from internal lab testing, engineering assessments, and risk management activities conducted by MRI Interventions, Inc. in the USA. The data is retrospective in the sense that it's generated during the design and manufacturing process, not from a prospective clinical trial.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of those Experts
Not applicable. This is not a study assessing diagnostic performance or requiring expert ground truth in the traditional sense. The "ground truth" for demonstrating the device works as intended comes from established engineering principles, recognized consensus standards, and comparison to the predicate device's cleared performance. Clinician request for the new drill sizes implies clinical input, but not as part of a formal ground truth adjudication.
4. Adjudication Method for the Test Set
Not applicable. There is no "test set" requiring adjudication by multiple experts, as this is a physical device clearance based on substantial equivalence and engineering verification.
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 is a manual surgical drill, not an AI/software device, and no MRMC study was conducted.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
Not applicable. This is a manual surgical drill, not an algorithm, and its use inherently involves human interaction.
7. The Type of Ground Truth Used
The "ground truth" for this submission revolves around:
- Predicate Device Performance: The established safety and effectiveness of the legally marketed MRII Cranial Drill.
- Consensus Standards: Compliance with recognized international and national standards (e.g., ISO 10993-1 for biocompatibility, ISO 11135-1 for sterilization, ASTM F2052-05e1 for MRI safety).
- Design Verification Testing: Internal testing to ensure the device meets its own design specifications.
- Risk Analysis: Identification and mitigation of potential risks.
8. The Sample Size for the Training Set
Not applicable. This is a physical medical device, not an AI/machine learning algorithm, so there is no concept of a "training set."
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no training set for this type of device.
§ 882.4300 Manual cranial drills, burrs, trephines, and their accessories
(a)
Identification. Manual cranial drills, burrs, trephines, and their accessories are bone cutting and drilling instruments that are used without a power source on a patient's skull.(b)
Classification. Class II (performance standards).