(76 days)
The Delia Localizer and Caroline Guide are indicated for use by neurosurgeons as shunt accessories for patients scheduled to undergo a posterior ventricular catheter placement procedure who are: 1) Adults 2) Have enlarged ventricles 3) Have normal scalp, skull, external ear and orbital anatomy 4) Do not have intracranial mass lesions or any structural abnormalities other than hydrocephalus 5) Have no general contraindications to surgery
The Delia Localizer is a head-band based apparatus that aids the surgeon in identifying the optimal location for placing a posterior burr hole for purposes of inserting a posterior ventricular catheter. It mechanically reduces to practice geometric principles that are already used to manually calculate where to position a posterior burr hole. The Caroline Guide is a mechanical device that helps the surgeon orient a ventricular catheter along a straight line connecting the posterior burr hole entrance point and the frontal target point.
The provided text describes a 510(k) summary for the "Caroline Guide and Delia Localizer" integrated system. However, it does not explicitly state specific numerical acceptance criteria or detail a study designed to prove the device meets these criteria in the typical quantitative manner we might expect for medical device performance evaluation.
Instead, the document focuses on:
- Substantial Equivalence: The primary goal of the 510(k) submission is to demonstrate that the new device is "substantially equivalent" to a legally marketed predicate device (a ventricular catheter stylette).
- Technological Characteristics: It highlights similarities in indications for use, method for advancing the catheter, and patient exposure to materials, while describing how the new device mechanically simplifies existing manual techniques.
- Pre-clinical Testing: This testing focused on confirming geometric principles and mechanical accuracy.
- Clinical Testing: A clinical trial of the Caroline Guide alone was reported in peer-reviewed literature. More recently, a clinical trial of the combined Delia Localizer and Caroline Guide system was approved, and clinical data on its performance was "now available."
Given this, I will reconstruct the "acceptance criteria" and "study" information based on the emphasis of the 510(k) process, which prioritizes safety and effectiveness demonstrated through substantial equivalence rather than explicit quantitative performance metrics like sensitivity/specificity often seen in AI/diagnostic device submissions.
Here's a breakdown of the requested information based on the provided text:
Acceptance Criteria and Device Performance
The concept of "acceptance criteria" in this 510(k) notice is primarily framed around the demonstration of substantial equivalence to a predicate device, and ensuring the new technological features do not adversely affect safety or effectiveness. Specific quantitative performance metrics are not provided as acceptance criteria.
| Acceptance Criteria (Implied by 510(k) content) | Reported Device Performance (Summary from text) |
|---|---|
| 1. Substantial Equivalence to Predicate Device: Same indications for use, method for advancing catheter, and materials exposure. | Met: The integrated system shares the same indications for use, method for advancing the catheter into the ventricle, and materials exposure to the patient during surgery as the predicate ventricular catheter stylette. The new features mechanically simplify existing manual techniques. |
| 2. Validity of Geometric Principles (Delia Localizer): Accurate embodiment of established geometric principles for burr hole placement. | Met: Pre-clinical testing involved anatomical analysis of CT scans of hydrocephalus patients, confirming the validity of the geometric principles. Testing on cranial phantoms of differing head sizes ensured accurate reduction of principles to practice. |
| 3. Mechanical Accuracy (Caroline Guide): Maintenance of catheter alignment with the frontal target point. | Met: Non-clinical studies confirmed that ventricular catheters passed through the guide tube maintained alignment with the frontal target point as advanced by hand. |
| 4. Safety and Effectiveness (Combined System): New technological features do not adversely affect safety or effectiveness. | Met: Pre-clinical and clinical test data indicate that the new technologic features of the Delia Localizer and Caroline Guide "do not adversely affect safety or effectiveness in a way that is consequential under the conditions of intended use." Clinical data from a trial using the combined system was available (approved by the University of Iowa Institutional Review Board). |
Study Details
The text describes both non-clinical and clinical tests. The primary "study" proving the device meets the substantial equivalence criteria encompasses these findings.
2. Sample size used for the test set and the data provenance:
- Delia Localizer (Pre-clinical):
- Test Set: Head CT scans of patients with hydrocephalus (number not specified).
- Provenance: Not explicitly stated, but implies clinical data from patients with hydrocephalus. The cranial phantoms used were for "differing head sizes."
- Caroline Guide (Non-clinical):
- Test Set: Not a human sample size, but involved testing with ventricular catheters and the guide tube.
- Caroline Guide (Clinical - standalone):
- Test Set: Not explicitly stated, but a clinical trial was conducted at the Universities of Iowa and Washington. This trial was reported in peer-reviewed literature in 1995. This would be prospective data given it was a trial.
- Delia Localizer + Caroline Guide (Clinical - combined system):
- Test Set: Clinical data (number of patients not specified) from a new clinical trial approved by the University of Iowa Institutional Review Board. This would be prospective data.
- Provenance: University of Iowa.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- For the pre-clinical analysis of CT scans, "anatomical analysis" was performed, which implies expert involvement, but the number and qualifications of experts are not specified.
- For the clinical trials, it is implied that neurosurgeons were involved in using and evaluating the device, but their number and specific qualifications for establishing 'ground truth' or evaluating outcomes are not detailed in this summary.
4. Adjudication method for the test set:
- Not specified. The 510(k) summary does not provide details on adjudication methods for either the pre-clinical or clinical studies.
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, an MRMC study was not done. This device is a mechanical surgical guide, not an AI-assisted diagnostic tool. Therefore, the concept of "human readers improve with AI vs without AI assistance" does not apply. The comparison is between manual surgical techniques and mechanically guided techniques. The summary states that the new device "mechanically reduces to practice geometric principles that are already used to manually calculate."
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, in essence. The pre-clinical tests for the Delia Localizer (validity of geometric principles, accuracy on phantoms) and the non-clinical tests for the Caroline Guide (mechanical accuracy with catheters) can be considered "standalone" evaluations of the device's mechanical function, prior to or separate from human-in-the-loop clinical use.
7. The type of ground truth used:
- Delia Localizer (Pre-clinical): Established geometric principles related to burr hole placement, confirmed by "anatomical analysis of head CT scans" and testing against physical cranial phantoms.
- Caroline Guide (Non-clinical): Mechanical alignment with a "frontal target point."
- Clinical Trials (Caroline Guide alone and combined system): Clinical performance, which for a surgical guidance device typically involves outcomes like successful catheter placement, reduction in complications, accuracy of placement, and patient safety. The specific metrics are not detailed but would be expert-assessed clinical outcomes.
8. The sample size for the training set:
- Not applicable in the typical sense of machine learning. This device is mechanical, not an AI/ML algorithm that requires a "training set." The development of the device would have been基于engineering principles and anatomical knowledge rather than data training.
9. How the ground truth for the training set was established:
- Not applicable as there is no "training set" in the context of an AI/ML algorithm. The "ground truth" for the device's design principles was established through anatomical and geometric understanding, surgical practice, and pre-clinical verification.
§ 882.4560 Stereotaxic instrument.
(a)
Identification. A stereotaxic instrument is a device consisting of a rigid frame with a calibrated guide mechanism for precisely positioning probes or other devices within a patient's brain, spinal cord, or other part of the nervous system.(b)
Classification. Class II (performance standards).