(103 days)
The Cranial Perforator is a sterile, single use cutting device intended for performing cranial trephination in bone at least 3 mm thick (i.e., adult skulls).
The Cranial Perforator per CFR, Part 882.4305, is a bone cutting and drilling instrument used in conjunction with a surgical motor and speed reducer attachment to drill holes through a patient's skull. The Cranial Perforator employs a clutch mechanism to disengage drilling action upon initial penetration of the skull to prevent plunging of the perforator tip into the underlying dura and brain tissues. The device is a Class II (USA) device. The Cranial Perforator is a device similar in design and construction to other devices currently on the market; (e.g.: Acra-Cut model DGR-1; 14/11mm). The Cranial Perforator is a compound drill which requires a motor to provide speed (70 - 80K RPM) and torque. But a speed reducer attachment is necessary to limit motor speed while delivering necessary torque. For this application the recommended motors are the Anspach Black Max. MicroMax and eMax motor systems. For speed reduction, it is recommended only the Anspach Speed Reducer attachments be used. The speed range when used with the listed Anspach equipment is 800 to 1200 RPM.
Here's an analysis of the provided text regarding the acceptance criteria and study for the Cranial Perforator:
The provided text describes a 510(k) submission for a Cranial Perforator. The primary goal of the submission is to demonstrate substantial equivalence to legally marketed predicate devices, specifically the Acra-Cut DGR-1 and Codman 26-1221. The performance testing focuses on demonstrating that the Anspach Cranial Perforator's declutch features are equivalent to the predicate, and that it meets user requirements for cutting rate and hole quality, without gross mechanical failures.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria / Performance Metric | Device Performance (Anspach Cranial Perforator) |
|---|---|
| Equivalence to Predicate Device (Acra-Cut DGR-1, Codman) | Found to be equivalent to competitors (Acracut and Codman) with respect to Plunge and Early Declutch failures. |
| Plunge Failures | Reported as equivalent to predicate devices. (Implied acceptance: no unacceptable plunge failures, similar to predicate). |
| Early Declutch Failures | Reported as equivalent to predicate devices. (Implied acceptance: no unacceptable early declutch failures, similar to predicate). |
| Cutting Rate | Found to meet the user requirement of a cutting rate equal to or greater than 0.24 mm/sec. |
| Hole Quality | Capable of creating clean holes when performing perforations. |
| Gross Mechanical Failures | Did not exhibit any gross mechanical failures. |
| Speed Range (when used with Anspach equipment) | Successfully operates within the range of 800 to 1200 RPM when used with recommended Anspach motors (Black Max, MicroMax, eMax) and Anspach Speed Reducer attachments. (This is a functional specification, not explicitly an acceptance criterion for the perforator itself, but rather for its intended use.) |
| Intended Use (cranial trephination in bone at least 3mm thick) | Intended for this use, implied successful performance in cadaver testing for this application. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The text states testing was performed on "human cadaver test samples." No specific number of cadaver samples or perforations is provided.
- Data Provenance: Human cadaver test samples. The country of origin is not explicitly stated, but given the US regulatory context and submitter, it's likely US-sourced cadavers. The study was prospective in the sense that the Anspach Cranial Perforator was directly tested, but the comparison to predicate devices uses their established performance as a benchmark.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
The text does not mention the use of experts to establish ground truth for the test set in the traditional sense (e.g., radiologists interpreting images). The assessment of "Plunge and Early Declutch failures," "cutting rate," "clean holes," and "gross mechanical failures" appears to be based on direct physical measurement and observation during cadaver testing, likely by engineers or technicians overseeing the mechanical performance test.
4. Adjudication Method for the Test Set
No explicit adjudication method (e.g., 2+1, 3+1) is mentioned or implied, as the performance metrics seem to be objective measurements or direct observations of mechanical function rather than subjective assessments requiring expert consensus.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No. An MRMC comparative effectiveness study was not conducted. This device is a mechanical surgical tool, not an imaging or diagnostic AI device that would typically involve human readers.
6. Standalone Performance Study
Yes. A standalone performance study of the Anspach Cranial Perforator was performed. The "Performance Testing" section states: "The Anspach Cranial Perforator (75-0002-1) was tested for performance and safety: refer to Verification Report 06-0708, using a comparative method to predicate cranial perforators Acracut and Codman." This testing evaluated the device's ability to:
- Perform without Plunge or Early Declutch failures (compared to predicates).
- Achieve a cutting rate equal to or greater than 0.24 mm/sec.
- Create clean holes.
- Operate without gross mechanical failures.
While a "comparative method" was used for some aspects (Plunge/Early Declutch), the other metrics (cutting rate, clean holes, no gross failures) indicate standalone performance evaluation against defined criteria.
7. Type of Ground Truth Used
The ground truth used is primarily physical performance metrics and direct observation on human cadaver bone, compared against established performance characteristics of predicate devices and user requirements. This isn't "expert consensus" or "pathology" in the medical imaging sense, but rather engineering-based verification.
8. Sample Size for the Training Set
Not applicable. This device is a mechanical surgical tool, not an AI/ML algorithm. Therefore, there is no "training set" in the context of machine learning.
9. How the Ground Truth for the Training Set Was Established
Not applicable. As above, there is no training set for a mechanical device.
§ 882.4305 Powered compound cranial drills, burrs, trephines, and their accessories.
(a)
Identification. Powered compound cranial drills, burrs, trephines, and their accessories are bone cutting and drilling instruments used on a patient's skull. The instruments employ a clutch mechanism to disengage the tip of the instrument after penetrating the skull to prevent plunging of the tip into the brain.(b)
Classification. Class II (performance standards).