830nm 대역 통과 필터

Context: This patent describes an Optical Coherence Tomography (OCT) system used to diagnose glaucoma by analyzing the Retinal Nerve Fiber Layer (RNFL).

Usage of Filter: The system utilizes an 830 nm bandpass filter (or source isolation) to direct a specific band of Near-Infrared (NIR) light into the eye. This 830 nm beam is often combined with a visible beam (e.g., 500 nm) using a beam combiner (dichroic filter) and then separated or analyzed using interferometry.

Function: The 830 nm light penetrates the retinal layers effectively, while the 500 nm light reflects off the surface. The filter ensures that only the relevant backscattered 830 nm signal is collected for the deep-tissue tomogram.

Result: The system achieves high-contrast differentiation of the RNFL from underlying tissues, enabling earlier and more accurate detection of glaucoma-related nerve damage than using reflectance intensity alone.

Context: A hybrid imaging system that combines an OCT scanner with a Line Scanning Laser Ophthalmoscope (LSLO) for comprehensive eye exams.

Usage of Filter: The system uses an illumination source in the 800–900 nm range (centered at ~830 nm). Optical filters are used in the detection arm to separate this imaging light from other potential signals or stray light.

Function: The 830 nm wavelength is used because it is invisible to the patient (preventing the pupil from constricting/closing during the scan) but detectable by standard silicon CCD/CMOS cameras.

Result: This allows for "non-mydriatic" imaging, meaning the doctor can get high-resolution, wide-field images of the retina without needing to use chemical drops to dilate the patient's pupils.