A humidifier for olfaction studies during functional magnetic resonance imaging

Functional magnetic resonance imaging has been used to study the transmission of olfactory sensations in the nervous system. Researchers hypothesize that olfactory sensation depends on the humidity of the air containing the odorant. We were asked to create this device for a biomedical design course offered at Worcester Polytechnic Institute. Our purpose was to create a device for researchers who are conducting initial research on rat models. The device allows researchers to provide a humidified source of oxygen safely to an anesthetized laboratory rat for up to six hour experimental sessions. Furthermore, the humidifier allows the user to manually control the humidity by a simple valve. In addition, the humidifier increases and decreases the humidity by slow increments to ensure the safety of the lab animal as well as the accuracy of the humidity readings. Finally, the design consists of two ports where a gaseous or liquid form odorant may be administered and evaluated for olfactory fMRI information. This device is a user-friendly, user-safe, and animal-safe method of odorant administration for fMRI studies. Moreover, this device can be easily expanded to become a computer-controlled humidifying system.