The majority of research into respiratory transport phenomena has commonly centred on adults, yet these findings are not always transferable, as children have distinct lung structures. Mapping and quantifying the nature of respiration in children could help clinicians treat respiratory conditions more effectively, as Associate Professor Josué Sznitman of the RespMicroFlows project explains
A deeper picture of respiratory transport The lungs are
a highly complex structure that closely resemble an upsidedown tree, with branches bifurcating from the main trunk into very small airspaces which are populated with alveoli, tiny sacs in which carbon dioxide and oxygen are exchanged. This is an area of great interest to Dr Josué Sznitman, the Principal Investigator of the RespMicroFlows project. “The essence of our research is that we work on mapping and quantifying the nature of respiration.
physics of flows and particle transport. “RespMicroFlows is taking these kinds of concepts and developing strategies on medication delivery through the lungs, with a focus on children,” says Dr Sznitman. The majority of research on respiratory transport phenomena has historically focused on adults, but now Dr Sznitman and his colleagues are looking to redress the balance. “In RespMicroFlows, we’re looking to see if we can make children-tailored models, to resolve the
The essence of our research is that we work on mapping and quantifying the nature of respiration. We’re very interested in delivering aerosols, in the context of inhalation therapy, to target specific regions of the respiratory tract and even more so for the young populations We’re very interested in delivering aerosols, in the context of inhalation therapy, to treat various types of diseases through inhaled medication,” he outlines. One important issue in treating certain respiratory conditions, including emphysema, is delivering drugs deeper into the lungs, past the main branches and into these very small airspaces where alveoli are located. “One of the approaches that has been advocated is to use inhalation therapy to deliver drugs directly to the deep lungs either for topical or systemic treatment,” explains Dr Sznitman.
RespMicroFlows project The primary focus in the RespMicroFlows project is investigating how aerosols can be delivered much deeper into the lung, which could greatly improve the effectiveness of treatment. This involves looking at a number of physical questions, including around fluid dynamics, the
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specificity of delivering aerosols in children,” he continues. “We’re developing numerical simulations and physical models of how air travels through the lung, how it travels through the trachea and makes its way down to the distal ends, or deep lungs.” This is a world that is characterised by very small scales, in the range of around 100 microns or so, with cavities barely the thickness of a hair. Delivering medication deep into this dense and populous environment is a complex challenge; researchers are using computational fluid dynamics (CFD) and physical models to build a clearer picture of how it can be achieved. “This includes using microfluidics very intensively in order to make airway models that capture the right scales of the alveolar environment, under a few hundred microns,” outlines Dr Sznitman. The project is also using sophisticated techniques to model airflows
in the lungs of an infant. “If you think about a new-born baby, or even a 2 year old, you can imagine their lungs are substantially smaller than an adult’s,” points out Dr Sznitman. “The largest airway is just a few millimetres, so you can imagine that everything downstream of that is going to be extremely small. There, we are using 3D printing techniques to reconcile the microfluidic world with these small yet millimetre-sized dimensions in upper airways.” The lung of an infant of course differs in size from that of an adult, but there is also still debate over exactly how the lung develops as we grow. It is thought that the main conductive structure of the lung is in place in a new-born, but the number of
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