(347 days)
The Minuteful - kidney test is an in-vitro diagnostic, home-use urine analysis test system for the semi-quantitative measurement of albumin and creatinine in urine, as well as the presentation of their ratio, the albumin-creatinine ratio (ACR). The system consists of a smartphone application, proprietary Color-Board and an ACR Reagent Strip. The system is available for prescription-use only and is intended for people at risk of kidney disease. Results are used in conjunction with clinical evaluation as an aid in the assessment of kidney health.
The Minuteful - kidney test is comprised of a kit and a smartphone application. It is intended for the semi-quantitative measurement of albumin and creatinine in urine, as well as the presentation of their ratio, the albumin-creatinine ratio (ACR). The Minuteful - kidney test is intended for prescription-use only, as a home-use device to aid in the assessment of kidney health. The results can be used together with clinical evaluation to guide patient care. The device's kit includes a urine receptacle, an ACR Reagent Strip, an absorbing (i.e. "blotting") pad, a proprietary Color-Board and a user manual. The device also consists of an easy-to-use smartphone application, image recognition algorithms, and a physician compendium. The software component of the Minuteful - kidney test consists of both an application (app) and a backend server. Both components encompass different computer vision and machine learning algorithmic components, performing the image analysis activities. The app instructs the user how to accurately administer the test. The Image Validation Transfer System (IVTS) component of the Minuteful - kidney test enables its usage across a wide range of smartphone types and operating systems, essentially making the test platform agnostic.
The provided text describes the Minuteful-kidney test (K222921) and its substantial equivalence to a predicate device (K210069). However, it specifically states that "The rest of the analytical performance studies are still relevant for the modified version of the Minuteful - kidney test, and their summary is available in the predicate device documentation (K210069)." This means the detailed acceptance criteria and the comprehensive study demonstrating the device meets those criteria are not present in this document but are referenced as being in the predicate device's documentation.
Therefore, I can report on the studies performed for K222921 to assert its substantial equivalence, but I cannot provide a table of acceptance criteria and reported device performance from this document for the overall device functionality as those details are in K210069. Nor can I provide information regarding sample sizes for test sets, expert qualifications, adjudication methods, MRMC studies, standalone performance, or ground truth details for K222921's overall performance since those are tied to the K210069 submission.
The studies described in K222921 (the current device) are focused on demonstrating that changes made to the device in K222921 do not negatively impact performance, thus maintaining substantial equivalence to its predicate.
Here's an analysis based solely on the provided text for K222921, noting the limitations:
Acceptance Criteria and Device Performance (Limited to K222921 changes):
Since the comprehensive performance data is referenced in K210069, the "acceptance criteria" discussed here are implicitly related to demonstrating that the modifications in K222921 (e.g., multilingual support, software enhancements) do not degrade the performance previously established for K210069. The studies conducted for K222921 focused on the robustness of the Image Validation Transfer System (IVTS) and the analytical limits of detection.
| Acceptance Criteria (Implied for K222921 changes) | Reported Device Performance (K222921) |
|---|---|
| Limit of Detection (LoD) | Testing was conducted in accordance with CLSI document EP17-A2. (Specific LoD values are not provided in this document but are likely in K210069). |
| Illumination Conditions | Performance is "not impacted" by different lighting conditions (color temperatures, intensities, light sources) representative of home use, nor by different light color saturations and intensities at the edges of device boundary conditions. |
| Physical Conditions | Performance is "not impacted" by different distance and angle conditions at the edges of device boundary conditions. |
| Multiple Shadow Conditions | Performance is "not impacted" by different shadow configurations (intensity, coverage) at the edges of device boundary conditions. |
| Blurriness | Performance is "not impacted" by different levels of focus and motion blur in images at the edges of device boundary conditions. |
| Misplaced Urine Stick | Performance is "not impacted" by different urine test strip placements at the edges of device boundary conditions. |
| Dirty Color-Board | Performance is "not impacted" by different dirty substances covering parts of the Color-Board at the edges of device boundary conditions. |
| Overall Equivalence to Predicate | The modified Minuteful-kidney test is concluded to be substantially equivalent to the predicate device (K210069), implying that the changes did not degrade its overall performance in terms of precision, interference, linearity, stability, and clinical performance, which are referenced back to the K210069 summary. The new IVTS system allows usage across a wide range of smartphone types and operating systems, making the test platform agnostic, without impacting performance in various challenging conditions. |
Study Details (for K222921 specific enhancements):
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Sample size used for the test set and the data provenance:
- Limit of Detection (LoD): The document does not specify the sample size for the LoD study for K222921. It mentions the study was designed and executed according to CLSI document EP17-A2.
- Illumination, Physical, Shadow, Blurriness, Misplaced Urine Stick, Dirty Color-Board Studies: The document refers to "Tested smartphones" and "different conditions," but specific numerical sample sizes (e.g., number of images, tests, or smartphones) are not provided. The data provenance is implied to be laboratory-controlled since these are experimental conditions, but no explicit country of origin or retrospective/prospective nature is stated for these new studies. The overall device is intended for home use, so these validations mimic adverse home conditions.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- This information is not provided in the K222921 document. These types of analytical studies typically rely on reference methods or scientifically established standards rather than expert consensus. For the clinical performance, the document refers to the predicate device K210069, where such details would likely be found if applicable.
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Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- Not applicable/Not provided for these specific analytical studies. The assessment of whether performance was "not impacted" would likely come from statistical analysis against pre-defined thresholds.
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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 MRMC or comparative effectiveness study involving human readers with and without AI assistance is mentioned in the K222921 submission. This device is an in-vitro diagnostic home-use test system where the smartphone app performs the measurement, rather than assisting a human in interpreting diagnostic images. Thus, the concept of "human readers improve with AI" in a traditional MRMC sense does not directly apply to this device's function.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- The core of the described studies (LoD, Illumination, Physical, Shadow, Blurriness, Misplaced Urine Stick, Dirty Color-Board) are indeed standalone performance tests of the device's algorithmic capability to accurately read the test strip under various challenging conditions encountered in a home setting. The device is described as having "image recognition algorithms" and performing "image analysis activities."
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- For the analytical studies described (LoD, Illumination, etc.), the ground truth would be based on controlled experimental conditions and potentially quantitative reference measurements (e.g., known concentrations for LoD, controlled lighting conditions). The document does not specify the exact methods for establishing this ground truth but implies scientific rigor (e.g., "in accordance with guidance provided by the Clinical and Laboratory Standards Institute (CLSI) document EP17-A2"). For the clinical performance aspects, the document refers to K210069.
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The sample size for the training set:
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How the ground truth for the training set was established:
§ 862.1645 Urinary protein or albumin (nonquantitative) test system.
(a)
Identification. A urinary protein or albumin (nonquantitative) test system is a device intended to identify proteins or albumin in urine. Identification of urinary protein or albumin (nonquantitative) is used in the diagnosis and treatment of disease conditions such as renal or heart diseases or thyroid disorders, which are characterized by proteinuria or albuminuria.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 862.9.