(188 days)
The Keeler Cryomatic System and probes are for use in ophthalmic surgery such as cryopexy for retinal detachment, cyclo destructive procedures in refractory glaucoma, extraction of fragments within the vitreous cavity, cataract extraction, cryo destruction of lash follicles for trichiasis and treatment of retinopathy of prematurity (ROP).
The Cryomatic MKII console is a self-contained system. The console consists of a rigid PU enclosure, housing the principle subsystems, switch mode power supply, controller PCB and pneumatic control module. On the front of the console is an LCD screen and membrane key panel. The console provides the connection point for the range of probe (reusable and disposable), footswitch, mains electricity, gas supply and scavenging system.
There is a variety of Keeler Re-usable Cryomatic Probes whose stainless tips are shaped depending on surgical application. The plastic handle is permanently connected to flexible pressure hose and integral connector, which connects to Cryomatic MKII Console.
The Keeler Disposable Cryo Probe comprises a stainless steel stem with a metal handle connected to a 2m long bi-lumen high-pressure plastic hose contained within a protective outer tube and terminated with a customdesigned plastic connector for insertion into the Cryomatic MKII console.
Here's a breakdown of the acceptance criteria and study information for the Keeler Cryomatic MKII System, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Evaluated Aspects) | Reported Device Performance |
|---|---|
| a) Probe external temperature and repeatability | Confirmed to be comparable with the predicate device. |
| b) Iceball growth capability | Confirmed to be comparable with the predicate device. |
| c) Defrost performance | Confirmed to be comparable with the predicate device. |
| d) Tractive power | Confirmed to be comparable with the predicate device. |
| Electrical Safety (IEC 60601-1) | In compliance with the standard. |
| Electromagnetic Compatibility (IEC 60601-1-2) | In compliance with the standard. |
| Sterilization of Re-usable Probes | Validation of the steam sterilization process was carried out to demonstrate that the sterilization parameters outlined in the instruction for use are sufficient to sterilize the modified probes. The modified device's sterilization methods (Pre-vacuum (porous load) 134 - 137 °C, 3 minutes and 18 minutes) were validated and deemed acceptable, despite differing from the predicate's gravity method and having only one method instead of two for some parameters. |
| Intended Use | Unchanged from the predicate device and the original 510(k) clearances (K062412 & K112093). The device maintains its indications for use in ophthalmic surgery (cryopexy for retinal detachment, cyclodestructive procedures, extraction of fragments, cataract extraction, cryodestruction of lash follicles, and treatment of retinopathy of prematurity). This was confirmed through a comparison of IFUs and overall assessment that the modifications do not affect safety or effectiveness. |
| Coupling Mechanism | The new quick-release coupling mechanism accepts both Keeler Cryomatic disposable and re-useable probes without an adaptor. This was observed as a design modification that did not affect safety or effectiveness. |
2. Sample Sizes Used for the Test Set and Data Provenance
The document does not explicitly state specific sample sizes for each verification test. It refers to "verification tests" and "all tests," implying a comprehensive evaluation.
- Data Provenance: The document does not specify the country of origin of the data or whether the studies were retrospective or prospective. Given that Keeler Instruments Inc. is based in Broomall, PA, USA, and the 510(k) is submitted to the FDA, it is highly probable that the testing was conducted in a manner consistent with US regulatory requirements for medical devices. The nature of the modifications (simplification of a coupling mechanism) suggests bench testing and internal validation rather than clinical trials with patient data.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not mention the use of experts to establish "ground truth" in the context of diagnostic accuracy. This submission is for a modification to an existing surgical system, not a diagnostic imaging device that requires expert interpretation. The "ground truth" for this device's performance would be established through engineering and performance testing against predefined specifications and recognized standards.
4. Adjudication Method for the Test Set
Not applicable. As described in point 3, this is a modification to a surgical device, not a diagnostic AI system requiring adjudication of expert interpretations.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
No. An MRMC comparative effectiveness study is not mentioned and would not be relevant for this type of device modification. This device is a surgical instrument, not an assistive technology for diagnostic interpretation.
6. If a Standalone Study (i.e., algorithm only without human-in-the-loop performance) was Done
Not explicitly applicable in the context of a "standalone algorithm." The device itself functions as a "standalone" surgical tool in that it performs its intended function without requiring human input beyond operating it. The "verification tests" described are essentially standalone performance evaluations of the modified hardware and associated software.
7. The Type of Ground Truth Used
The "ground truth" for this device modification is based on:
- Engineering Specifications: The device's performance (probe temperature, iceball growth, defrost, tractive power) was measured against established specifications for the predicate device and the new design.
- Safety Standards: Compliance with recognized international standards (IEC 60601-1 for electrical safety, IEC 60601-1-2 for electromagnetic compatibility).
- Sterilization Validation: Specific protocols and measurements to ensure the re-usable probes could be adequately sterilized according to defined parameters.
8. The Sample Size for the Training Set
Not applicable. This device is not an AI/ML algorithm that requires a "training set" in the conventional sense. The "training" for this device would be its design, engineering tolerances, and manufacturing processes.
9. How the Ground Truth for the Training Set was Established
Not applicable for the same reasons as point 8.
§ 886.4170 Cryophthalmic unit.
(a)
Identification. A cryophthalmic unit is a device that is a probe with a small tip that becomes extremely cold through the controlled use of a refrigerant or gas. The device may be AC-powered. The device is intended to remove cataracts by the formation of an adherent ice ball in the lens, to freeze the eye and adjunct parts for surgical removal of scars, and to freeze tumors.(b)
Classification. Class II.