(40 days)
The Z-type Digital Keeler Applanation Tonometer is indicated for measuring intraocular pressure to aid in the screening and diagnosis of Glaucoma.
The Z-type Digital Keeler Applanation Tonometer is a screening device used to measure intraocular pressure which is one of the factors considered in diagnosing glaucoma. The product is an active medical device, powered by a single AA battery. The operation principal is based on Goldmann applanation method.
The provided text is a 510(k) summary for a modified medical device, the Z-type Digital Keeler Applanation Tonometer. The primary focus of this document is to demonstrate "substantial equivalence" to a predicate device, rather than to establish new performance criteria for a novel device. As such, it relies heavily on the fact that existing performance characteristics (like measurement deviation, range, and technique) remain unchanged.
Here's an analysis of the acceptance criteria and study information available in the document:
1. A table of acceptance criteria and the reported device performance
Since this is a submission for a modified device claiming substantial equivalence, the "acceptance criteria" are essentially the performance characteristics of the predicate device, which the modified device is expected to match. The document explicitly states "No change" for most performance-related characteristics when comparing the modified device to the predicate device.
| Characteristic Feature | Acceptance Criteria (Predicate Device Performance) | Reported Device Performance (Modified Device) | Notes |
|---|---|---|---|
| Type | Manual contact Tonometer | Manual contact Tonometer | No change. |
| Indicated Use | Measuring intraocular pressure to aid in the screening and diagnosis of Glaucoma. | Measuring intraocular pressure to aid in the screening and diagnosis of Glaucoma. | No change. |
| Intended Use | Intraocular Pressure (IOP) measurement | Intraocular Pressure (IOP) measurement | No change. |
| Target Population | Patients with high IOP | Patients with high IOP | No change. |
| Anatomical Sites | Cornea | Cornea | No change. |
| Where Used | In a professional healthcare facility environment | In a professional healthcare facility environment | No change. |
| Units of Measure | mmHg - millimeter of mercury | mmHg - millimeter of mercury | No change. |
| Display | Numerical display - Direct reading of IOP in mmHg from display | Numerical display - Direct reading of IOP in mmHg from display | No change. |
| Measurement Range | 5-65mmHg | 5-65mmHg | No change. |
| Measurement Technique | Applanation | Applanation | No change. |
| Measurement Method | Goldmann method - the measuring of pressure to maintain a uniform applanation of the surface of the eye. | Goldmann method - the measuring of pressure to maintain a uniform applanation of the surface of the eye. | No change. |
| Measurement Deviation | 0.49 mN or 1.5% of measurement value, whichever is the greater. | 0.49 mN or 1.5% of measurement value, whichever is the greater. | No change. |
| Power Requirements | AA Battery to power digital display | AA Battery to power digital display | No change. |
| Software | Contains software | Contains software | No change. |
| Maintenance and Calibration | Maintenance and calibration required, factory set. Calibration arm assembly supplied with each device. | Maintenance and calibration required, factory set. Calibration arm assembly supplied with each device. | No change. |
| Materials | Tonometer body - anodized aluminium; Tonometer prism - Medical grade acrylic. | Tonometer body - anodized aluminium; Tonometer prism - Medical grade acrylic. | No change. |
| Biocompatibility | All materials are tested for biocompatibility. | All materials are tested for biocompatibility. | No change. |
| Design / Mounting | Mounted on top illuminating (Haag-Streit-style) Slit lamp, manual dial. (Predicate device K093445) | Mounted on bottom-illuminating (Zeiss-style) Slit lamp, manual dial. | Change in shape of the device to allow mounting on bottom-illuminating slit lamp (Zeiss-type illumination system). The change does not affect the intended use, safety and effectiveness or the fundamental scientific technology. |
| Mounting method on slit lamp | Fixed (R-Type) and Take-away (T-Type) | Fixed | No change (referring to the modified device being fixed, which is a specific characteristic of the Z-type mentioned in the product description, not necessarily a change from the predicate which may have had both fixed and take-away options). The comparison table is a bit ambiguous here as it lists "Fixed (R-Type) and Take-away (T-Type)" for the predicate and "Fixed" for the modified, but then says "No change." It seems to imply that the new model is just one type of mounting. |
2. Sample sized used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
The document mentions "Verification tests have been carried out in accordance to the FDA guidelines 'Tonometers - Premarket Notification [510(k)] Submissions'." However, it does not specify the sample size for any clinical or performance test set, nor does it provide details about data provenance (country of origin, retrospective/prospective). The tests mentioned are primarily engineering verification tests (electrical safety, EMC, software).
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
No information is provided regarding the number or qualifications of experts used to establish ground truth for any clinical test set. Given it's a 510(k) for a modification and claims substantial equivalence based on engineering verification, explicit clinical ground truth establishment with experts is not detailed.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
No information is provided regarding an adjudication method.
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
This device is not an AI-assisted diagnostic tool. It is a physical tonometer. Therefore, an MRMC comparative effectiveness study involving human readers and AI assistance is not applicable and was not performed.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
The device is a manual contact tonometer that requires a human operator for its use. It is not an algorithm-only standalone device.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
For the mechanical and electrical verification mentioned, the ground truth would be based on established engineering standards (e.g., ISO 8612:2009 for tonometer calibration, BS EN 60601-1 for electrical safety, BS EN 60601-1-2 for electromagnetic compatibility). For the primary function of measuring IOP, the gold standard is stated as the "Goldmann tonometer." The document indicates that the device's operating principle is based on the Goldmann method, and its measurement deviation aligns with previous models.
8. The sample size for the training set
This is not an AI/machine learning device, so there is no concept of a "training set" in the traditional sense. The device's "training" or calibration is factory-based using known pressures and a calibration arm.
9. How the ground truth for the training set was established
For the calibration process, the ground truth is established by "known pressures covering the measurement range applied to the measurement arm using a calibration arm verified using the calibration procedure outlined in the Tonometer standard ISO 8612:2009." This means the ground truth for the device's accuracy is derived from international standards for tonometer calibration.
§ 886.1930 Tonometer and accessories.
(a)
Identification. A tonometer and accessories is a manual device intended to measure intraocular pressure by applying a known force on the globe of the eye and measuring the amount of indentation produced (Schiotz type) or to measure intraocular tension by applanation (applying a small flat disk to the cornea). Accessories for the device may include a tonometer calibrator or a tonograph recording system. The device is intended for use in the diagnosis of glaucoma.(b)
Classification. Class II.