@article {Kaisti79, author = {Kaike K. Kaisti and Jukka M{\"a}kitalo and Hannu T. Sipil{\"a} and Mika I.P. Ter{\"a}s and Harry Scheinin}, title = {Ventilator Add-On for Delivering PET Tracer Gases}, volume = {32}, number = {2}, pages = {79--82}, year = {2004}, publisher = {Society of Nuclear Medicine}, abstract = {Objectives: The increasing use of PET for assessing cerebral blood flow, oxygen metabolism, and blood volume in critically ill patients has created a need for reliable technical solutions for delivering 15O-tracer gases to mechanically ventilated subjects. Our objective was to create such a solution. Methods: We designed a ventilator add-on unit that enables complex functional brain studies using labeled oxygen and carbon monoxide gases as tracers. The unit manages both steady-state and bolus inhalations, and the latter can be manually initiated using a remote trigger. All parts conducting breathing gases can be sterilized. The unit can be operated during both spontaneous pressure support breathing and volume-controlled ventilation. It supports the standard safety features and alarms of the ventilator and includes an overflow valve in the bolus reservoir. Results: The count rate curves obtained using the new unit were similar to those from the standard bag-inhalation method. Conclusion: The unit we describe offers an economical and easily operated solution for providing uninterrupted ventilator treatment while performing PET brain studies, and the provided treatment meets intensive care criteria.}, issn = {0091-4916}, URL = {https://tech.snmjournals.org/content/32/2/79}, eprint = {https://tech.snmjournals.org/content/32/2/79.full.pdf}, journal = {Journal of Nuclear Medicine Technology} }