Whole Slide Scanner Specifications

1. Scanning principle and light path

• Brightfield transmitted scanning as standard, multicolour fluorescence optional

• Line scan with continuous motion, or area scan with step-and-stitch

• Autofocus by image contrast or laser assist, focusing per field in real time

• Automatic white balance and illumination uniformity correction, leaving no seams after stitching

• Z-stack scanning to pick the best focal plane in thick sections

2. Objectives and resolution: the key item

• 20X objective as standard, 40X optional

• Numerical aperture of 0.75 or more at 20X, 0.95 or more at 40X

• Indicative resolution of 0.25 micrometre per pixel at 20X and 0.12 at 40X

• Optical and pixel resolution stated separately, interpolation adds no real detail

• Note: pathology diagnosis generally needs 20X or higher, with 40X for nuclear detail

3. Speed and throughput

• A 15 x 15 mm tissue area scanned in 60 seconds or less at 20X brightfield

• Continuous loading of 6 slides or more, with 8 and 12 slide options

• Unattended batch scanning, moving to the next slide automatically

• Speed and image quality assessed together, since over-compression to gain speed loses diagnostic information

4. Slide loading and compatibility

• Standard slides of 25 x 75 mm, 1.0 to 1.2 mm thick

• Compatible with common mountants and stains such as HE, Pap and immunohistochemistry

• Automatic barcode reading with laboratory information system integration as an option

• Magazine removable as a unit for batch loading

5. Image output and formats

• Output in SVS, TIFF, JPEG2000 or a proprietary format, with a statement on exporting to common formats

• Pyramidal multi-resolution storage for fast zooming

• Export of single fields and of annotated regions

• Colour management following an ICC workflow for consistency between displays

6. AI analysis and viewing

• Optional AI modules for cell counting, nuclear-cytoplasmic ratio, immunohistochemistry quantification and chromosome analysis

• Viewing over the local network or in a browser, without a dedicated workstation if required

• Measurement, annotation, capture and sharing for consultation

• AI results traceable through model version, parameters and source image

7. Network and storage

• A 20X whole slide image runs from 200 MB to 1 GB, so size storage by daily volume

• Dedicated NAS or server recommended, archived by case

• Gigabit network as a minimum, 10 gigabit where several people view at once

• Regular backup, since images are primary medical or research data

8. Power and environment

• Power supply AC 220 V, 50 Hz

• Operating temperature 5 to 40 degrees Celsius, relative humidity up to 80 percent, dust kept out

• UPS recommended, an interrupted scan loses the current slide

• Clean the light path and stage guides periodically

9. Three points where procurement often goes wrong

• Only 40 megapixels is quoted without objective power or true resolution, and interpolated images cannot be used for diagnosis

• Speed is quoted on the smallest tissue area, while a full slide takes several times longer

• Output is a closed format with no export, which blocks later AI or consultation integration