Surgical lighting
A surgical light – also referred to as an operating light or surgical lightheadis a medical device intended to assist medical personnel during a surgical procedure by illuminating a local area or cavity of the patient. A combination of several surgical lights is often referred to as a “surgical light system”. History. Technical development. In the mid-1850s, operating rooms were built towards the southeast with windows in the ceiling to benefit from natural sunlight as much as possible. The biggest problem was the dependence of lighting and whether a procedure could be done on the time of day and  weather conditions. Furthermore, a doctor, nurse or medical equipment easily blocked the light. The use of mirrors on the four corners of the ceiling to reflect sunlight towards the operating table only slightly alleviated these problems. Attempts were made to use an optical condenser in an indirect light to reduce the heating, but without success. The entrance of electric lights into the operating room in the 1880s was accompanied by problems. With early electrical technology control of the light emitted was poor. Electric light was still moving and diffuse, with great heat radiation. Light-emitting diodes as light sources remove  the problem of heat radiation and reduce energy requirements. Norms and requirements for surgical light. The International Electrotechnical Commission (IEC) created the document "IEC 60601-2-41 – Particular requirements for the basic safety and essential performance of surgical luminaires and luminaires for diagnosis, 2009 " to establish norms and guidelines for the characteristics of a surgical and examination light to secure safety for the patient as well as lower the risk to a reasonable level when the light is used according to the user manual. Some of the standards for surgical lightheads are the following: