Tunable white light source for medical applications

Development of light-emitting diodes has brought new possibilities in many applications, especially in terms of flexible adjustment of spectra of light. This feature is very useful in construction of many devices, for example lamps for medical diagnosis and treatment. It was proved, that in some cases LEDs can easily replace lasers during therapy of cancer without reduction of efficiency of this process. On the other hand during diagnosis process LED-based constructions can provide that the image of the examined tissue in the light of different colors is much more contrast.
In the paper we describe the construction of the tunable LED-based tunable source designed for application in endoscopy. It was optimized from the point of view of the color rendition for 5 different correlated color temperatures (illuminant A, D55, D65, 3500K and 4500K) with the restriction of very high (>90) values of general and specific color rendering indexes (according to Ra method). The source is composed of 13 light-emitting diodes from visible region mounted on the common radiator and controlled by dedicated system. Spectra of the components are mixed and the spectra of output light are analyzed. On the basis of obtained spectra colorimetric parameters are calculated and compared with the results of theoretical analysis.

This research was conducted with financing from the statutory work S/WE/4/2013 (Ministry of Science and Higher Education Republic of Poland) in the Department of Electric Power Engineering, Photonics and Lighting Technology, Bialystok University of Technology.