The efficacy of infrared filter window film to prevent hyperthermia in neonatal hyperbilirubinemia with conventional phototherapy: a randomized control trial

BACKGROUND

Phototherapy is the first-line treatment of neonatal hyperbilirubinemia. Possible side effects caused by phototherapy include hyperthermia and dehydration. Currently, there are many types of infrared blocking film for potential use in reducing infrared radiation exposure and preventing hyperthermia. This study aims to evaluate the efficacy of infrared blocking film in preventing hyperthermia during the first 24 h of phototherapy.

METHODS

The randomized controlled trial study was carried out in 44 newborns with hyperbilirubinemia. Infrared filter film with 75% visible light transmission and 90% infrared rejection was used in the study. Body temperature was measured for the assessment of the efficacy of filter film from axillary and rectal routes.

RESULTS

There was a significantly lower incidence of hyperthermia from the axillary temperature in the group with infrared blocking film compared to the control group (p = 0.031). The axillary temperature between before and after initiation of phototherapy in filter film group was significantly better (p = 0.008). According to efficacy of treatment, the study demonstrated that infrared filter film did not interfere with the efficacy of phototherapy in reducing bilirubin level.

CONCLUSIONS

The infrared filter film was significantly more effective in preventing hyperthermia from phototherapy in the first 24 h without causing any significant difference in reduction of bilirubin level.

THAI CLINICAL TRIALS REGISTRY

TCTR20190619001.

Evolving random fractal Cantor superlattices for the infrared using a genetic algorithm

Ordered and chaotic superlattices have been identified in Nature that give rise to a variety of colours reflected by the skin of various organisms. In particular, organisms such as silvery fish possess superlattices that reflect a broad range of light from the visible to the UV. Such superlattices have previously been identified as ‘chaotic’, but we propose that apparent ‘chaotic’ natural structures, which have been previously modelled as completely random structures, should have an underlying fractal geometry. Fractal geometry, often described as the geometry of Nature, can be used to mimic structures found in Nature, but deterministic fractals produce structures that are too ‘perfect’ to appear natural. Introducing variability into fractals produces structures that appear more natural. We suggest that the ‘chaotic’ (purely random) superlattices identified in Nature are more accurately modelled by multi-generator fractals. Furthermore, we introduce fractal random Cantor bars as a candidate for generating both ordered and ‘chaotic’ superlattices, such as the ones found in silvery fish. A genetic algorithm is used to evolve optimal fractal random Cantor bars with multiple generators targeting several desired optical functions in the mid-infrared and the near-infrared. We present optimized superlattices demonstrating broadband reflection as well as single and multiple pass bands in the near-infrared regime.