Use of a hand-held spectroradiometer for the measurement of neonatal phototherapy lamp outputs

Abstract

The measurement capability of a hand-held spectroradiometer for validation of phototherapy light treatment for neonates is described. This function is compared with that of a double grating monochromator system with photomultiplier detector, where parameters evaluated included wavelength accuracy and accuracy of irradiance within set wavelength intervals - 460 nm to 490 nm and 400 nm to 550 nm. Measurements carried out in a clinical setting revealed that the hand-held spectroradiometer provided an acceptable level of accuracy for determining output characteristics of the phototherapy devices investigated. It was observed that measurement errors were more significant for studies involving direct contact with light emitting surfaces. It was identified that the spectral resolution of the MSC15 device could act to degrade the accuracy of the device where narrow spectrum peaks occurred around the limits of specific identified bandwidths - such as at 460 nm and 490 nm. This was identified not to be an issue with typical light emitting diode phototherapy systems, where the spectral outputs do not contain narrow spectral components. The device lends itself also to use by clinical staff in the clinical environment to verify the output of phototherapy lamps. The availability of such hand-held spectroradiometer devices represents an advance on the use of output meters suppled by equipment manufacturers.

Keywords: Bilirubin; Neonatal phototherapy; Spectoradiometer.