Novel Highly Efficient System for Breath-Triggered Aerosol Delivery for Preterm Infants using Non-Contact Breath Capture

Felix C. Wiegandt1, Luisa K. Ermoneit1, Ulrich P. Froriep1 and Gerhard Pohlmann1

1Fraunhofer Institute for Toxicology and Experimental Medicine, Nikolai-Fuchs-Stra├če 1, 30625 Hannover, Germany

Summary

A major and costly disadvantage of inhalation therapy with continuous drug delivery to patients is its inefficiency, also often leading to ineffectiveness. Breath-triggered drug release systems can highly improve efficiency. Preterm infants have especially challenging breathing patterns with breathing frequency up to 1 Hz, low tidal volume (4-6 ml/kg) and short inspiration times (0.2-0.4 s). There is currently no technology available enabling breath-triggered drug release directly into the patient interface for (pre)term infants. The breathing pattern has to be detected in order to deliver an aerosolized drug in a breath-triggered manner. For (pre)term infants, contact-based sensors such as the Graseby capsule are usually employed. However, these have the drawback of being highly position-dependent and can irritate or, in the worst case, injure the sensitive skin of preterm infants. Therefore, we developed a system combining (1) a novel patient interface with (2) a non-contact breath detection unit to enable breath-triggered aerosol release in preterm infants.

As test substance saline solution was aerosolized with a mesh nebulizer and delivered to a preterm neonate test bed via a standard interface (FlexitrunkTM) and our novel interface, respectively. For breath detection abdominal movement of preterm infants was recorded with a time-of-flight camera.

We achieved up to 2.5-fold (non-triggered) and 4-fold (triggered) dose increase with the novel patient interface compared to the standard interface. Breathing patterns were reliably extracted from the abdominal movement data to generate trigger signals.

Thus, despite the extreme respiratory patterns of preterm infants, our system enables a very efficient breath-triggered drug release.

Key Message

A system has been developed that is able to release medical aerosol in a breath-triggered manner using a novel patient interface in combination with a non-contact breath detection unit. This system is up to 4 times more efficient than standard of care.