Dynamically Controlled LED Luminaire for Contrast Visualisation of Biological Tissues During Surgical Procedures

The article reviews the main theoretical, engineering and technological, circuit-engineering and software aspects of development of a dynamically controlled luminaire based on light emitting diodes for contrast visualisation of biological tissues during surgical procedures. The design concept of such surgical luminaire is proposed, which combines high-quality white lighting and coloured accent lighting increasing the contrast of visualisation of particular tissues and borders between them. The calculation model of the luminaire optical system allows maximising the level of illumination and uniformity of illuminance and colour of the surgical area. The software of the luminaire allows to independently modifying intensity of radiation of six coloured light emitting diodes with blue (460 nm), turquoise (505 nm), green (530 nm), green-yellow (550 nm), orange (590 nm) and red (630 nm) light colours for synthesis of coloured lighting of virtually any chromaticity. The level of general lighting by means of phosphor light emitting diodes can also be varied within a wide range. Chromaticity and level of lighting are adjusted by means of pulse-duration modulation of light emitting diode current and the light parameters of the luminaire are controlled by a remote computer via a radio channel. This medical luminaire is primarily designed for lighting during surgical procedures and it can also be used for visual diagnostics based on the colour of analysed tissues.