This chapter discusses the mathematical modeling process and how it can be an effective tool in developing a virtual lab of simulation for medical devices, with lung therapy devices in particular. The chapter introduces the concept of “Talkative Models” in biomedical applications. The discussion includes some criteria for selecting “Talkative Models”: conditions imposed on the interfaces between the models; requirements of biological and medical device models; performance criterion; and a typical case study that applies the model of a Bubble continuous positive airway pressure (CPAP) device to lung models that represent lungs with respiratory distress syndrome (RDS) to assess device...