(29 days)
The Clarifi™ Imaging System is indicated for use to determine oxygenation levels in superficial tissues for patients with potential circulatory compromise.
The Clarifi Imaging System is intended for use by healthcare professionals as a non-invasive tissue oxygenation measurement system that reports an approximate value of:
- Oxygen saturation (StO2) ●
- Oxyhemoglobin (HbO2), and .
- Deoxyhemoglobin (HbR) .
in superficial tissue.
The Clarifi Imaging System is a noninvasive non-contact imaging device used to visualize spatially-resolved functional parameters of biological tissue. The Clarifi Imaging System shares fundamental principles with other oximeters and tissue oxygenation measurement systems. Tissue oximetry exposes tissue to optical radiation of known wavelengths and captures the remitted light or reflectance. The remitted-back scattered light is then used to calculate the tissue constituents. Spectral analysis is used to measure tissue oxygen saturation (StO2), oxyhemoglobin (HbO2), deoxyhemoglobin (HbR), and total hemoglobin (HbT: superficial and subsurface hemoglobin) and determine tissue optical properties (absorption and scattering). The Clarifi Imaging System uses both visible (VIS) and near-infrared (NIR) wavelengths; other systems that also measure oxygenation levels in superficial tissue may use only VIS or NIR wavelengths. The analysis for Clarifi is based on principles of multi-spectral imaging and Spatial Frequency Domain Imaging (SFDI).
The Clarifi system displays two-dimensional color-coded images of tissue oxygenation of the scanned surface and reports hyperspectral tissue oxygenation measurements for selected tissue regions.
Here's an analysis of the acceptance criteria and study proving device conformance, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The provided document does not explicitly state acceptance criteria in a quantitative table format. Instead, it focuses on demonstrating substantial equivalence to a predicate device (Ox-Imager CS - K153426) based on similar performance and design. The performance data section describes verification testing, which implies internal acceptance limits were met, but these limits are not explicitly listed as "acceptance criteria."
However, we can infer some performance aspects from the "Performance Testing" section:
| Acceptance Criteria (Inferred from Performance Testing) | Reported Device Performance (Clarifi Imaging System) |
|---|---|
| Linearity of diffuse reflectivity (vs. NIST-traceable Spectralon standards) | Strong, linear agreement (r² > 0.9) with predicate device |
| Precision of reflectivity measurements | Within specifications ( 40 |
2. Sample Size for the Test Set and Data Provenance
- Sample Size for Test Set: Not explicitly stated as a number of patients or cases. The performance testing was done on "NIST-traceable Spectralon standards" and "reflectance targets," which suggests a benchtop test rather than a clinical study with patient samples.
- Data Provenance: The testing was conducted as "bench performance data... under design validation 21 CFR 820.30(g)." This indicates internal laboratory testing, not patient data from a specific country or setting.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
- Number of Experts: Not applicable. The "ground truth" for the bench performance tests was based on "NIST-traceable Spectralon standards" and physical "reflectance targets," which have known properties, not expert interpretation.
4. Adjudication Method for the Test Set
- Adjudication Method: Not applicable. The performance testing was based on direct measurements against established physical standards and device specifications, not on expert adjudication of ambiguous cases.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- MRMC Study Done? No. The submission focuses on demonstrating substantial equivalence through technical and bench performance comparisons to a predicate device, not through a comparative effectiveness study with human readers.
6. Standalone Performance (Algorithm only without human-in-the-loop performance)
- Standalone Performance Done? Yes, effectively. The reported performance data (linearity, precision, stability, image homogeneity, SNR) are measurements of the device's intrinsic capabilities and performance characteristics as a standalone system (Clarifi Imaging System) when compared against physical standards and its predicate device. There is no mention of a "human-in-the-loop" component for these specific validation tests.
7. The Type of Ground Truth Used
- Type of Ground Truth: For the performance tests, the ground truth was based on physical standards (NIST-traceable Spectralon standards) and known properties of reflectance targets.
8. The Sample Size for the Training Set
- Sample Size for Training Set: The document does not describe a "training set" in the context of machine learning or AI models. The Clarifi Imaging System uses "principles of multi-spectral imaging and Spatial Frequency Domain Imaging (SFDI)" and "spectral model-based analysis." This indicates a physics-based model rather than a data-driven machine learning model that would typically require a training set. Therefore, this concept is not applicable as described in the provided text.
9. How the Ground Truth for the Training Set Was Established
- How Ground Truth for Training Set Was Established: Not applicable, as there is no mention of a training set for a machine-learning model. The system relies on physical principles and models to determine oxygenation levels.
§ 870.2700 Oximeter.
(a)
Identification. An oximeter is a device used to transmit radiation at a known wavelength(s) through blood and to measure the blood oxygen saturation based on the amount of reflected or scattered radiation. It may be used alone or in conjunction with a fiberoptic oximeter catheter.(b)
Classification. Class II (performance standards).