title: Standardized bench method for evaluating the efficacy of phototherapy devices.
abstract: OBJECTIVE
  As phototherapy (PT) devices employ a variety of broadband light sources, we developed and tested a standardized bench method for evaluating the efficacy of some devices.
  
  
  METHODS
  To evaluate efficacy, we quantified the in vitro photodegradation rate (expressed as t1/2) of unconjugated bilirubin in solution at 37 degrees C during exposure to a given light source at its mean delivered irradiance to the 2D body surface area (BSA) of newborn models. Reproducibility (between-day variation) of the method was determined at irradiance levels from 10 to 70 microW/cm2/nm on three different days.
  
  
  RESULTS
  Between-day t1/2 measurements had coefficients of variation from 3% to 10%. When t1/2 values were normalized to the exposable 2D horizontal BSA, halogen lamp devices, without and with fiberoptics, were least effective (t1/2=60-108 min and 100-126 min for preterm and term models, respectively). Fluorescent tube devices had t1/2=19-78 min and 25-78 min, for preterm and term models, respectively. Light-emitting diode (LED)-based devices yielded the shortest t1/2 values (16-24 min) for preterm and term newborn models.
  
  
  CONCLUSIONS
  We demonstrated the applicability of the method through the determination of the efficacy of several commercially available PT devices. This standardized method is reproducible and effectively evaluates the relative in vitro efficacy of various devices and may guide further in vitro and in vivo evaluations of devices.
authors.affiliation: Department of Pediatrics, Stanford University School of Medicine, Stanford, California 94305-5208, USA. henk.vreman@stanford.edu
authors.forename: H J
authors.initials: HJ
authors.lastname: Vreman
authors.forename: R J
authors.initials: RJ
authors.lastname: Wong
authors.forename: J R
authors.initials: JR
authors.lastname: Murdock
authors.forename: D K
authors.initials: DK
authors.lastname: Stevenson
mesh_terms: D001830:Body Surface Area; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007567:Jaundice, Neonatal / Q000628:therapy; D010789:Phototherapy / Q000295:instrumentation*; D015203:Reproducibility of Results