Low-pressure mercury-vapor discharge lamp for treatment of hyperbilirubinemia and method

DETAILED DESCRIPTION There is provided a lamp combination for phototherapeutic treatment of hyperbilirubinemia, including a low-pressure mercury-vapor discharge lamp having a hollow elongated vitreous envelope with electrodes operatively disposed proximate the ends thereof.
The envelope encloses a discharge sustaining atmosphere comprising mercury and an inert, ionizable starting gas.
The improvement in the combination is a coating of selected phosphors carried as a layer on the inner surface of the envelope substantially comprising blue-radiating alkaline-earth metal halophosphate activated by divalent europium and a phosphor with a color output that falls within an area of an xy-C.
I.
E.
coordinate diagram, said area constituting a trapezium with corners at xy-C.
I.
E.
coordinates (0.
423, 0.
370), (0.
370, 0.
410), (0.
445, 0.
550), (0.
515, 0.
484) with a weight ratio of alkaline-earth metal halophosphate activated by divalent europium to the second phosphor being from about 90:10 to 85:15.
When treating infantile hyperbilirubinemia with such a lamp, any tendency of the blue emission of the europium-activated alkaline-earth metal halophosphate to produce nausea in certain attendant individuals is substantially eliminated without appreciably affecting the efficacy of the treatment process.