(111 days)
The Gemini is indicated for the fragmentation of urinary tract stones, i.e., renal calyceal stones, renal pelvic stones, and upper ureteral stones.
The Gemini is a modular urological work station designed for extracorporeal shock wave lithotripsy ("ESWL") and for diagnostic and therapeutic procedures usual in Urology. The Gemini is composed of the following modules: (1) basic unit with integrated X-ray C-arm and therapy arm for shockwave treatment; (2) patient table; (3) control desk – user interface; and (4) ultrasound unit.
The provided document is a 510(k) summary for the Gemini Lithotripter, detailing modifications to previously cleared predicate devices. It describes the device's intended use, technological characteristics, and conformance to various safety and performance standards. However, it does not include detailed acceptance criteria or a specific study proving the device meets those criteria in the way a clinical performance study would.
Here's an analysis based on the provided text, addressing your points:
1. A table of acceptance criteria and the reported device performance
The document does not specify quantitative acceptance criteria for clinical performance (e.g., stone fragmentation rates, stone-free rates, re-treatment rates). Instead, it relies on demonstrating substantial equivalence to predicate devices and compliance with a list of recognized standards and internal design control processes.
The "reported device performance" is primarily stated as: "In all instances, the Gemini Lithotripter functioned as intended and results observed were as expected." and "the system met all acceptance criteria" during internal design control.
| Acceptance Criterion (Implicit) | Reported Device Performance |
|---|---|
| Compliance with IEC 60601-1 (Electrical safety) | Complied |
| Compliance with IEC 60601-1-2 (Electromagnetic compatibility) | Complied |
| Compliance with IEC 60601-1-3 (Radiation protection) | Complied |
| Compliance with IEC 60601-1-6 (Usability) | Complied |
| Compliance with IEC 60601-2-7 (Safety of high-voltage X-ray) | Complied |
| Compliance with IEC 60601-2-28 (X-ray source assemblies) | Complied |
| Compliance with IEC 60601-2-36 (Extracorporeally induced Lithotripsy) | Complied |
| Compliance with IEC 60601-2-32 (Safety of X-ray equipment) | Complied |
| Compliance with ISO 13485 (Quality management system) | Complied |
| Compliance with IEC 61846 (Ultrasonics - Pressure pulse lithotripters) | Complied |
| Functionality of anti-collision system | Verified to perform as designed to mitigate the risk of injury. |
| Accuracy of stone localization methodology | Tested during design verification testing; assessment demonstrated the system is capable of locating the shock wave focus area with sufficient accuracy. |
| Device manual review | Reviewed and approved as part of design control process; contains all necessary warnings, cautions, and instructions to mitigate potential injuries. |
| Overall performance vs. Intended Use and Predicates | "In all instances, the Gemini Lithotripter functioned as intended and results observed were as expected." and "Performance data demonstrate that the Gemini Lithotripter is as safe and effective as the predicate devices." (This is a general statement rather than specific performance metrics.) |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
The document does not mention a clinical "test set" in the context of human patients or image data for evaluating an AI/algorithm's performance. The testing described focuses on engineering verification and validation against standard requirements and internal acceptance criteria during the design control process. There is no indication of retrospective or prospective clinical study data provenance mentioned for the submitted data.
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)
Not applicable. No clinical test set requiring expert ground truth is described. The "ground truth" for the engineering performance was established by the design specifications and regulatory standards.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not applicable. No clinical test set requiring adjudication is described.
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. This document does not mention any multi-reader multi-case (MRMC) comparative effectiveness study or any AI component designed to assist human readers. The device is an extracorporeal shock wave Lithotripter, a physical medical device for stone fragmentation, not a diagnostic AI system.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
Not applicable. The device is a physical Lithotripter, not solely an algorithm. While it has software for control and image storage, the "performance" described pertains to the overall system's operation and safety, not a diagnostic algorithm operating in a standalone mode. The "assessment demonstrated that the system is capable of locating the shock wave focus area with sufficient accuracy," which is an algorithm-driven function, but its evaluation isn't detailed as a standalone algorithm performance study.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
For the engineering and safety tests, the "ground truth" refers to the pass/fail criteria defined by the recognized standards (IEC, ISO) and the device's design specifications. For the "accuracy of stone localization methodology," the ground truth would have been derived from physical measurements against known targets or possibly phantom studies. No patient outcomes data, pathology, or expert consensus on clinical findings is mentioned as ground truth for the provided performance data.
8. The sample size for the training set
Not applicable. This is not an AI/ML device that would typically have a "training set" in the context of deep learning models for image analysis or diagnosis. The device's underlying technology (electromagnetic shock wave emitter, X-ray, ultrasound) is well-established.
9. How the ground truth for the training set was established
Not applicable, as there is no mention of a training set for an AI/ML model.
Summary of the Document's Approach:
The K121656 510(k) summary focuses on demonstrating substantial equivalence to predicate devices (Dornier Lithotripter (Doli) and Doli 140) based on:
- Identical Intended Use/Indications for Use.
- Similar Technological Characteristics/Principles of Operation: The core component (140f EMSE shock wave source) is identical to those in cleared devices. Other components (patient table, X-ray unit) are "similar to that of other cleared stationary Lithotripters" and "perform the same function and operate in the same manner."
- Compliance with Recognized Standards: A comprehensive list of IEC and ISO standards for electrical safety, EMC, radiation protection, usability, and specific Lithotripter requirements were met.
- Internal Design Control Testing: The company states that the system and its software were tested and validated, meeting "all acceptance criteria" during their design control process. Specific mention is made of the anti-collision system performing as designed and the stone localization methodology demonstrating sufficient accuracy.
This type of 510(k) submission, particularly a Special 510(k) as indicated, often relies heavily on demonstrating that modifications do not raise new questions of safety or effectiveness, rather than requiring extensive de novo clinical trials or AI performance studies with large, expert-adjudicated datasets. The "study" proving the device meets acceptance criteria is the sum of the documented engineering tests and validations against the listed standards and internal specifications, demonstrating its functional equivalence and safety compared to the predicates.
§ 876.5990 Extracorporeal shock wave lithotripter.
(a)
Identification. An extracorporeal shock wave lithotripter is a device that focuses ultrasonic shock waves into the body to noninvasively fragment urinary calculi within the kidney or ureter. The primary components of the device are a shock wave generator, high voltage generator, control console, imaging/localization system, and patient table. Prior to treatment, the urinary stone is targeted using either an integral or stand-alone localization/imaging system. Shock waves are typically generated using electrostatic spark discharge (spark gap), electromagnetically repelled membranes, or piezoelectric crystal arrays, and focused onto the stone with either a specially designed reflector, dish, or acoustic lens. The shock waves are created under water within the shock wave generator, and are transferred to the patient's body using an appropriate acoustic interface. After the stone has been fragmented by the focused shock waves, the fragments pass out of the body with the patient's urine.(b)
Classification. Class II (special controls) (FDA guidance document: “Guidance for the Content of Premarket Notifications (510(k)'s) for Extracorporeal Shock Wave Lithotripters Indicated for the Fragmentation of Kidney and Ureteral Calculi.”)