Technology

Tracking Laser Tomography - Combining the Best of cSLO and SD-OCT

Heidelberg Engineering is the first company to introduce tracking laser tomography, a technology which enables real-time, simultaneous imaging while tracking eye movement. Utilizing our TruTrack™ image alignment software, the Spectralis^® is able to continuously monitor the position of the eye using a beam of light. Once eye tracking is engaged, the Spectralis^® tracks the motion of the eye and can direct a second beam of light to the correct position like a missile tracking system.

The ability to have eye tracking, retina recognition, and automatic rescan at the same location are key characteristics of this new hybrid technology known as tracking laser tomography.

Heidelberg Noise Reduction™ for Imaging is like Dolby^® Noise Reduction for Sound

Heidelberg Noise Reduction™ uses our TruTrack™ software to produce high quality images. Applying our eye tracking technology, multiple images are obtained from the same exact location. These images are compared and combined, filtering random noise (sometimes called “speckle”) from the final image. This is similar in concept to the way that Dolby® Noise Reduction produces high fidelity sound in recordings.

Automatic Rescan at Follow-up

TruTrack™ precisely tracks change over time by automatically looking for the same area on the retina. Using a selected prior reference scan, the Spectralis^® aligns the reference fundus image with the live patient fundus image at follow-up. The Eye Tracker recognizes the retina and then directs the SD-OCT scan to the same location. This eliminates subjective placement of the scan by the operator.

Confocal Imaging Blocks the Haze

Confocal imaging is the process of shining light on an object, then capturing reflected light by passing the light through a pinhole. The pinhole blocks light not coming from the plane or layer of interest and blocks scattered light which can “fog” the image. The result is focused, high resolution images without glare.

40,000 A-Scans per Second: Fastest Available SD-OCT

Spectralis^® is the fastest commercially available spectral-domain OCT instrument, scanning 100 times faster than time-domain OCT at 40,000 A-scans per second. Spectral-domain OCT (also known as Fourier-domain OCT) uses a broadband light source to simultaneously measure multiple wavelengths across a spectrum, hence the name “spectral-domain”. The older time-domain systems use a moving reference mirror for measuring the return time of the light from the retina. This mechanical moving reference mirror limited the speed at which data could be acquired. Since it works on the “time of flight” principle, it is known as “time-domain” OCT. Spectralis^® is the only instrument to center the SD-OCT wavelength at 870 nm. This gives the instrument better light penetrating properties than other systems using shorter 820 nm light. Also, the longer wavelength has the advantage of opening up the optical window for compatibility with the many other wavelengths used by the system.