PHOTOTHERAPY APPARATUS AND METHOD FOR HYPERBILIRUBINEMIA TREATMENT

摘要

In apparatuses and methods for the medical treatment of hyperbilirubinemia, itis known to usephototherapy lamps in a manner that exposes the patient to an essentiallysteady stream of light.Even the "intermittent" variety of known phototherapy methods arecharacterized by steadyexposure to light whereby the light remains continuously on during theirrelatively long "lights-on" segments of treatment, such a continuously-on segment lasting on the orderof many minutesto several hours. In this invention, however, light is delivered to thepatient instead in burstpulses greatly shortened in duration, down to tiny fractions of a second, toapproach the merenanoseconds-long time period actually required to cause the molecular-leveltherapeuticphotoisomerization of bilirubin. Such flashes of light are then repeated onlyoften enough toaccommodate or match the actual bilirubin migratory rates of the particulartissue being targeted.The short-duration flashes spaced in time as far apart as possible insequential cycling can thusreduce to a minimum total light irradiance dose, therefore helping to minimizethe potential forphototoxic side effects. This in turn allows the use of greatly increasedintensity of light fordeeper penetration into patients' target tissue to allow a greater number ofbilirubin molecules tosimultaneously undergo molecular photoisomerization, all to thetherapeutically advantageouseffect of more rapid lowering of serum bilirubin levels. Even with such use ofgreatly-increasedintensity of light, actual total irradiance dose to the patient can in factstill remain lower than withpreviously known phototherapy approaches since the invention so unprecedentlyeliminatesexposure during strategic, extensive 'blackout' periods which the Applicanthas discovered asbeing unnecessary for coverage by light exposure given the actual relationshipof required timeperiods of bilirubin molecular geometric structure alteration byphotoisomerization and bilirubinmigration in target tissue. The light source used can be of virtually any safetype that includes inits emission sufficient energy levels in the appropriate wavelength range,while specifically axenon flash tube embodiment would allow for particularly efficient electronicflashing of thelight and also possesses the property of yielding a therapeutically optimaloutput emphasisaround the blue wavelengths portion (400 to 500 nanometers) of the visiblespectrum. In anotherembodiment based more on traditional phototherapy light sources, the short-duration flashes canbe produced by various mechanical shutter or electrical means. Light deliveryto relevant tissuein the patient can be accomplished by any of various external, internal, orsurgical means.