Automatic Respiratory Gas Delivery Device for Noninvasive Administration of Hyperpolarized Gaseous Contrast Agents to Consciously Breathing Subjects

Kiarash Emami¹, Hooman Hamedani¹, Biao Han¹, Yinan Xu¹, Stephen J. Kadlecek¹, Masaru Ishii², Rahim R. Rizi¹

The design of an automatic MRI-compatible respiratory gas mixing, delivery and monitoring device capable of administering a predefined tidal volume and concentration of gaseous contrast agents to consciously breathing subjects is described. This system divides the mixture of hyperpolarized gas and oxygen over several breaths for multi-breath imaging protocols or oxygen-weighted MRI, queues the subject (without the risk of over-inflating the lungs) and synchronizes image acquisition with MRI scanner. This device eliminates the need for operator supervision by responding to subjects voluntary respiratory effort, and makes it possible to maintain a respiratory pattern very similar to normal breathing.