(182 days)
The XyCAM RI System is intended to capture, store, and display images of dynamic blood flow changes in the human retina, and to provide quantitative outputs of relative blood flow information.
The XyCAM™ RI System (or XyCAM RI) is a non-invasive retinal blood flow imaging device. It generates images of one or more regions of the retina by using an imaging technique called Laser Speckle Contrast Imaging (LSCI). This technique utilizes a lowintensity laser beam to illuminate the back of the eye and a high-speed, high-sensitivity camera to acquire a stack of images. The captured image stack is then processed such that the intensity at every image pixel is processed in conjunction with the intensities of other spatio-temporally adjacent pixels to obtain a speckle contrast value at the said pixel. which is indicative of blood flow velocity at the said pixel. Accordingly, the XyCAM RI is able to generate and display a map of Blood Flow Velocity indices within the imaged field of view.
The XyCAM RI System consists of following modules:
- The XyCAM RI contains a module to provide illumination to the back of the eye, various optical components to manipulate light along the illumination and imaging path, a high-speed camera to capture images, visual targets for the imaged subject to fixate his/her gaze on during imaging, and electronic and mechanical components for control and operation.
- System PC contains the XyCAM RI Software. The Operator uses the XyCAM RI System PC keyboard, mouse, and monitor to interact with the XyCAM RI Software, which controls the XyCAM RI operation including management of user and patient information, control of image acquisition, facilitation of image analysis, and generation of imaging results.
- Accessories include an imager station and an external hard drive.
- A pulse oximeter is included as an optional third-party device.
The XyCAM RI Software outputs Blood Flow Velocity indices (arbitrary units) that can be assessed for spatial and temporal trends in user defined regions.
The XyCAM RI System is intended to capture, store, and display images of dynamic blood flow changes in the human retina, and to provide quantitative outputs of relative blood flow information.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:
1. A table of acceptance criteria and the reported device performance
While explicit acceptance criteria (e.g., "CV must be less than X%") are not directly stated in the provided text as numerical targets prior to the results, the study design implicitly aims to demonstrate good repeatability and reproducibility. Therefore, the reported performance metrics serve as the de facto "met" acceptance criteria.
| Metric (Implicit Acceptance Criteria) | Reported Device Performance (XyCAM RI) |
|---|---|
| Intra-session Repeatability (ONH region) | Mean intra-session CV: 2.883 ± 1.049% |
| Inter-session Reproducibility (ONH region) | Mean inter-session CV: 7.069 ± 2.018% |
| Intra-session Repeatability (Macular region) | Mean intra-session CV: 2.782 ± 2.044% |
| Inter-session Reproducibility (Macular region) | Mean inter-session CV: 6.447 ± 3.778% |
| Bench Testing - Intrasession CV vs. Calibrated Flow Pump | "Intrasession coefficient of variation significantly less than 10%" |
| Bench Testing - Comparative assessment with RFI 3000 | "Demonstrated substantial equivalence between the two outputs and consistent repeatable measurements of physiologically relevant blood flow velocities" |
| Software Level of Concern | Moderate (addressed by verification and validation testing) |
| Electrical Safety and EMC Compliance | Complies with ANSI/AAMI ES60601-1 and IEC 60601-1-2 |
| Illumination Classification and Safety | Class 1 Laser Product (IEC 60825:2007) and Group 1 Ophthalmic Instrument (ANSI Z80.36-2016) |
2. Sample size used for the test set and the data provenance
- Sample Size for Clinical Test Set: 20 healthy subjects.
- Data Provenance: The text does not explicitly state the country of origin of the data. It is implied to be prospective since it describes "subjects were recruited and imaged" as part of the clinical testing.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
The text does not mention the use of experts to establish a "ground truth" for the blood flow measurements in the clinical study. The study focuses on the device's own measurement repeatability and reproducibility, and its ability to generate images, rather than comparing its diagnostic output to an expert-validated diagnosis.
- Number of Experts: Not applicable/not mentioned for clinical ground truth.
- Qualifications of Experts: Not applicable/not mentioned.
4. Adjudication method for the test set
The text describes an assessment of measurement errors across imaging sessions and operators in the clinical study but does not detail an adjudication method for discrete classifications or diagnoses. The analysis involved calculating coefficients of variation (CV) for regions of interest (ROIs) across multiple cardiac cycles and imaging sessions.
- Adjudication Method: Not applicable/not mentioned for adjudicating a diagnosis or classification. The study focused on quantitative measurement variability. For the clinical performance, imaging sessions were conducted by one operator for Group A1 and by three operators for Groups A2 and A3 to assess operator variability.
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
- MRMC Study: No, a multi-reader multi-case comparative effectiveness study with human readers assessing improvement with AI assistance was not mentioned. The device, XyCAM RI, provides quantitative outputs of relative blood flow information and is not described as an AI-assisted diagnostic tool for human readers in the way a typical MRMC study would evaluate.
- Effect Size: Not applicable.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, the primary performance evaluation described for the XyCAM RI System is a standalone performance assessment. The device itself (algorithm only, as it processes captured images) generates quantitative outputs (Blood Flow Velocity indices or BFVi). The clinical study evaluated the repeatability and reproducibility of these outputs when the device was used in a clinical setting.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The clinical study did not use an external "ground truth" such as pathology or expert consensus for the retinal blood flow measurements. Instead, the study's goal was to demonstrate the device's intrinsic reliability through repeatability and reproducibility of its own measurements in healthy subjects.
- For bench testing, a calibrated flow pump was used as a reference to analyze the device's ability to reliably capture retinal blood flow.
8. The sample size for the training set
The document does not explicitly state a training set size. The XyCAM RI System utilizes Laser Speckle Contrast Imaging (LSCI) for blood flow measurement, which is a physics-based imaging technique. While such systems might involve some internal calibration or model parameters, the document does not suggest a deep learning or machine learning model that would typically have a distinct "training set" in the context of diagnostic AI. The term "training set" is generally used for machine learning models, which is not clearly indicated as the core technology for the XyCAM RI.
9. How the ground truth for the training set was established
Since a "training set" in the context of machine learning is not explicitly mentioned or implied as part of the core technology described, the method for establishing its ground truth is also not provided. The system's operation is based on the physical principles of Laser Speckle Contrast Imaging.
§ 886.1120 Ophthalmic camera.
(a)
Identification. An ophthalmic camera is an AC-powered device intended to take photographs of the eye and the surrounding area.(b)
Classification. Class II (special controls). The device, when it is a photorefractor or a general-use ophthalmic camera, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 886.9.