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Indicated Use is for scanning, mapping, and displaying the geometry of the anterior segment of the eye. Also indicated for the measurement and analysis of optical aberrations of the eye by use of wavefront technology.

The NGDI Workstation comprises two individual measuring systems. The Anterior Segment Analyzer measures elevation and curvature on both the anterior and posterior surfaces of the cornea, full corneal pachymetry, white-to-white, anterior chamber depth and angle kappa. The Anterior Segment Analyzer in the NGDI Workstation is a diagnostic system that provides a complete analysis of the eye's optical system by utilizing slit scanning technology with an advanced Placido disc system. The slit scan is used to create the pachymetry model in the NGDI Workstation, which gives the thickness of the cornea and the location of the lens. The Aberrometer is a precision optical instrument which measures the deviation of light beams reflected off the eye's retina to define the wavefront deformation as a function of the position of the pupil. It uses a motor-controlled trombone to set up the optical path for the eye image to return through in complete focus. The Aberrometer function of the NGDI employs the principles of Hartman-Schack wavefront sensing in which a narrow illumination beam from a 785 mm, low power, laser diode goes into the eye and focuses into a diffraction limited point on the retina. The light reflects off the retina and comes back out the eye. The light exiting the eye is then passed through an array of tiny lenses (the lenslet array) that tak the exiting rays of light and breaks them into small points. With a normal, regular pattern, one can see where there is a plain wavefront with a uniform and symmetric grid and regular spacing between the points. Aberrated wavefronts are characterized by a distortion of the grid pattern after the light passes through the lenslet array.

Here's a breakdown of the acceptance criteria and study information for the NGDI (Next Generation Diagnostic Instrument) based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state formal "acceptance criteria" for clinical performance. Instead, it presents a comparison of the NGDI's performance to a predicate device (Orbscan) in terms of repeatability and error statistics for keratometric power using test objects. The implicit acceptance is that the NGDI should perform comparably to or better than the predicate device.

2. Sample Size Used for the Test Set and Data Provenance

• Sample Size: The document refers to "a number of test objects." A specific numerical count is not provided.
• Data Provenance: Not specified. The study was non-clinical, using "test objects," not human patient data.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

• Number of Experts: Not applicable. The ground truth was established by the known curvatures of the "test objects," which are physical standards, not human interpretations.
• Qualifications of Experts: Not applicable.

4. Adjudication Method (e.g., 2+1, 3+1, none) for the Test Set

• Adjudication Method: Not applicable. The ground truth for the test objects was intrinsic (known curvature), not based on human adjudication.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done

• MRMC Study: No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. The study focused on instrument performance with test objects.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done

• Standalone Performance: Yes, the study focused on the standalone performance of the NGDI and Orbscan instruments in measuring test objects. There was no human-in-the-loop component in this specific non-clinical test.

7. The Type of Ground Truth Used

• Ground Truth Type: Known physical properties of "test objects" (specifically, their curvatures).

8. The Sample Size for the Training Set

• Training Set Sample Size: Not applicable. This document describes a non-clinical testing phase for device comparison, not a machine learning algorithm that requires a training set. The device itself (NGDI) is an optical instrument, not an AI/ML algorithm.

9. How the Ground Truth for the Training Set Was Established

• Ground Truth for Training Set: Not applicable, as there was no training set for an AI/ML algorithm.

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