Contactless multiple wavelength photoplethysmographic imaging: A first step toward "spO2 camera" technology

We describe a route toward contactless imaging of arterial oxygen saturation (SpO2) distribution within tissue, based upon detection of a two-dimensional matrix of spatially resolved optical plethysmographic signals at different wavelengths. As a first step toward SpO 2-imaging we built a monochrome CMOS-camera with apochromatic lens and 3λ-LED...

Absorption of the eye lens and macular pigment derived from the reflectance of cone photoreceptors

We measured the amplitude of the directional component of the bleached fundus reflectance, the so-called optical Stiles-Crawford effect, as a function of wavelength. The directional reflectance originates from within the outer segments of the photoreceptors. Thus only two anterior absorbers are of importance: Macular pigment and the crystalline...

Developments in radiographic caries diagnosis

The developments that have been taking place in radiographic caries diagnosis, within the context of the changes occurring in both the disease process and the available technology, are reviewed. The decline in caries prevalence seen in many western countries has been accompanied by changes in the pattern and behaviour of lesions. More lesions...