Engineering and Physics in Respiratory Diagnostics and Therapeutics

抄録

Understanding, diagnosing and treating respiratory diseases is more important now than ever due to increasing pollution as well as the current and future pandemics. Inhaled air may contain dust, bacterial and viral particles that can irritate a person's nose, throat or airways. This irritation can easily turn into an allergic reaction. Furthermore, if particles reach deep alveolar regions of the lung, bacterial and viral particles can cause severe pneumonia leading to some form of acute respiratory distress syndrome (ARDS). For example, the SARS-Cov-2 virus can bind to cell surface receptors on type II alveolar epithelial cells and following internalization and replication, the virus may cause a lung disease, the Covid-19, which, in its severe form, invariably requires mechanical ventilation. The mortality rate of ARDS unrelated to SARSCov-2 is between 30% and 40%, whereas that of Covid-19 is higher than 50%. Thus, detection of particles, diagnosing the early symptoms and treating patients with the mild and severe form of lung diseases require tools that combine engineering and physics with biology, immunology and nanomedicine. In this presentation, I will discuss 4 areas of interdisciplinary research that are at the forefront of respiratory diagnostics and therapeutics. 1) Modeling the interaction of particle properties, airflow and complex airway geometry to better understand where inhaled particles are deposited. Our recent work suggests that particle transport in a complex branching structure can be modeled using a Markov chain approach which not only provides a deposition map, but can also be used to optimize inhalation strategies for targeted delivery of drug particles. 2) Mechanical ventilation methods to minimize the risk of full blown ARDS and maximize resources for optimal strategies ventilating patients. First, I will describe 2 types of mechanical ventilation, airway pressure release ventilation (APRV) and variable ventilation (VV), both of which have the potential to mitigate ARDS and accelerate recovery. Next, I will describe a new engineering method to safely individualize management of multiple patients using a single ventilator. 3) A novel method, called ZVV, which can be used both as a diagnostic and a therapeutic tool when ARDS patients require mechanical ventilation. The diagnostic aspect of ZVV is related to the specific mode of ventilation offered by VV, namely, that tidal volume and frequency is varied from cycle-to-cycle. Analyzing each breath separately, allows us to reconstruct the impedance spectrum Z of the respiratory system over a range of frequencies. Features of Z can in turn guide ventilation protocols, while VV itself helps recruiting the lung and hence minimizing ventilator-induced lung injury. 4) Mechanical vibrations utilized as therapeutic means to reduce irregular breathing in preterm infants. I will describe 2 methods of applying mild vibrations to infants that have the potential to reduce irregular breathing and hence the risk of sudden infants death syndrome. Before concluding, I will highlight possible areas where engineering and physics can be further utilized to solve outstanding biological and medical problems of our times. In summary, it may be expected that the presented engineering and physics methods together with other methods that already exist or are waiting to be developed, will help public health combat respiratory diseases in the future.