Anthropomorphic optical phantom of the neonatal thorax: a key tool for pulmonary studies in preterm infants.

Andrea Pacheco,Monisha Chakravarty,Sanathana Konugolu Venkata Sekar,Stefan Andersson-Engels,Haiyang Li

doi:10.1117/1.jbo.25.11.115001

Andrea Pacheco, Monisha Chakravarty + Show 3 more

Open Access

https://doi.org/10.1117/1.jbo.25.11.115001

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Abstract

.Significance: Gas in scattering media absorption spectroscopy (GASMAS) is a technique for gas sensing in cavities surrounded by scattering materials. GASMAS could be translated to the clinic to monitor lung function continuously and noninvasively in neonates. Accurate tissue phantoms are essential to assess the strengths and limitations of gas spectroscopy in gas-containing cavities in the human body.Aim: The aim is to develop a detailed protocol to produce a long-lasting, multistructure tissue phantom of the thorax of a neonate. The phantom mimics the geometry and the optical properties of the main organs of the thorax and has an empty pulmonary cavity that facilitates GASMAS monitoring of gas content.Approach: The anatomic geometry of heart, lungs, bones, muscle, fat, and skin was obtained from a neonatal computed tomography scan. Once segmented, organs were 3D printed and used to create negative rubber molds. The entire thorax was built in phantom material (silicone as matrix, black ink as absorber, and silica microspheres as scatters) by placing all phantom organs inside the muscle structure. Our phantom recipe was customized by mixing specific ratios of ink and spheres to match the optical properties of the different organs that were consider to be homogeneous.Results: An anthropomorphic thorax phantom with the desired optical properties ( and ) at 760 nm was built and used to obtain “transdermal” GASMAS measurements of oxygen content within the lung cavity.Conclusion: A protocol to build a robust optical phantom of the thorax of a neonate was used to conduct benchtop studies. This recipe can be implemented to reproduce the geometry and optical properties of any human or animal tissue.

Highlights

Over the last decade, the feasibility of the clinical translation of gas in scattering media absorption spectroscopy (GASMAS) to measure the existence and concentration of gas in the human body has been pursued.[1]
The geometry of the phantom and materials that mimics the absorption and scattering properties of human tissue are chosen according to the intended use
Anthropomorphic computer models of the relevant organs within the thorax were created after segmenting the organs in a computed tomography (CT) scan

Summary

Introduction

The feasibility of the clinical translation of gas in scattering media absorption spectroscopy (GASMAS) to measure the existence and concentration of gas in the human body has been pursued.[1]. The geometry of the phantom and materials that mimics the absorption and scattering properties of human tissue are chosen according to the intended use. To accurately characterize clinical devices in biophotonics, there is a need to develop anthropomorphic phantoms that mimic both optical properties and morphological features of human organs.12–14 3D printing techniques have been used to replicate complex anatomic structures, such as human breast.[15] reduced scattering and absorption properties of 3D-printed phantoms are, so far, restricted to the mixing compatibility of the printing material with scattering particles and ink. Most of the 3D printers just print one material at a time, making it impossible to obtain a phantom with diverse optical properties in a single cross section

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