Breath-Triggered Drug Release for Preterm Neonates

Inhalation therapy is a form of treatment for respiratory diseases. However, a major disadvantage of inhalation therapy with continuous drug delivery to the patient is the waste of drugs during exhalation. The development of a breath-triggered drug delivery system can greatly reduce this waste. Furthermore, in preterm and term neonates, this is further complicated by their challenging respiratory parameters such as high respiratory rate, low tidal volume, and short inhalation times. Given these challenges, there is currently no technology that enables breath-triggered drug release directly at the patient interface of preterm and term neonates. To close this gap, it is not only necessary to develop devices that enable efficient drug release at high frequencies, but also test beds that can be used to determine the efficiency of drug release. Moreover, the respiratory phases must be detected to release the aerosol in synchrony with the respiration.

Therefore, an overall system consisting of aerosol output determination, breath-triggered aerosol release, and breath detection published by Wiegandt et al. is presented in this thesis as follows:
1. A test bed, consisting of gravimetric and optical particle detection which allows the determination of the aerosol output in real time as well as the determination of the particles' water content.
2. A breath-triggered aerosol delivery system consisting of a novel patient interface with an integrated micronized aerosol valve which allows direct and rapid breath-triggered delivery of aerosol as a targeted bolus at different times of inhalation.
3. A respiratory detection system consisting of a time-of-flight camera for recording the abdominal movement of preterm neonates which enables the determination of respiratory parameters.