# Web Applications for Teaching the Respiratory System: Content Validation
###### Abstract  
The subject of respiratory mechanics has complex characteristics, functions, and interactions that can be difficult to understand in training and medical education contexts. As such, education strategies based on computational simulations comprise useful tools, but their application in the medical area requires stricter validation processes. This paper shows a statistical and a Delphi validation for two modules of a web application used for respiratory system learning: (I) \"Anatomy and Physiology\" and (II) \"Work of Breathing Indexes\". For statistical validation, population and individual analyses were made using a database of healthy men to compare experimental and model-predicted data. For both modules, the predicted values followed the trend marked by the experimental data in the population analysis, while in the individual analysis, the predicted errors were 9.54% and 25.38% for maximal tidal volume and airflow, respectively, and 6.55%, 9.33%, and 11.77% for rapid shallow breathing index, work of breathing, and maximal inspiratory pressure, respectively. For the Delphi validation, an average higher than 4 was obtained after health professionals evaluated both modules from 1 to 5. In conclusion, both modules are good tools for respiratory system learning processes. The studied parameters behaved consistently with the expressions that describe ventilatory dynamics and were correlated with experimental data; furthermore, they had great acceptance by specialists. respiratory system; communication technologies; model validation; ventilatory signals; work of breathing indexes +
Footnote †: journal: Medicaldecreasing the work of breathing and does not generate an unnecessary burden on the patient [4]. Some ventilation indexes have been proposed to assess the effect of MV. Three of them are widely used, owing to their ease of application in daily clinical practice: the _work of breathing_ (WOB) index, which describes the energy required to achieve ventilation [5]; _rapid shallow breathing index_ (RSBI), proposed by [PERSON] and [PERSON] in [6] to quantify the degree of shallow breathing, defined as the ratio of respiratory frequency (RR) to tidal volume (V\({}_{\text{T}}\)); and _maximal inspiratory pressure_ (PI\({}_{\text{max}}\)), described as a measure of the strength of inspiratory muscles, primarily the diaphragm, which allows for the assessment of ventilatory failure, restrictive lung disease, and respiratory muscle strength [7]. Maintaining airflow within the pulmonary airways requires a pressure gradient that falls along the direction of flow, the magnitude of which is determined by the flow rate, the frictional resistance to flow, and the elastic recoil of the lungs and the chest wall; the respiratory muscles must overcome those loads for ventilation [8; 9]. In fact, like any other mechanism involving fluid dynamics, the respiratory system responds according to thermodynamics and fluid mechanics laws [10], including the equation of air motion. This expression relates the pressure in the system to the different values of volume and airflow as a function of time and the system's mechanical characteristics (elastance and resistance), so all the respiratory mechanics can be described [11]. Due to the relationship between the dynamics of the respiratory system and classical physics, understanding respiratory behavior may be challenging for some regular students. Moreover, there are medical, scientific, and educational interests to promote medical students' training in the interaction of mechanical properties in the ventilatory process to determine an accurate and effective treatment with timely diagnostics for some respiratory pathologies. Some studies [12; 13] highlight the advantages of implementing communication and information technologies in the teaching-learning process. For medical training, students approve in silico didactic strategies that facilitate their learning through intuitive and interactive tools.