Providing effective low-cost back lighting for localized surgical procedures

A method of providing back light illumination was developed in the context of injecting rat fetuses. The illuminator had a compact flat design measuring approximately 2.6 cm x 6 cm, with minimal thickness (about 7 mm), and a proportionately large amount of active area. The top working surface was a glass plate through which the illumination was provided. The head provided diffuse light and remained relatively cool during operation. The unit was water proof (suitable for immersion in a warm saline bath) and provided isolation from hazardous voltages. The head was able to be freely positioned, with a small, flexible power lead that exited from a non-active area of the unit. The head was free of sharp or rough edges and was suitable for direct contact with delicate tissues.