Olfactory Measurement System to Quantify the Ability to Smell Using Pulse Ejection

Olfaction is a very important sense in daily life. Decline in olfaction has been reported to be an early symptom of diseases such as Alzheimer's and Parkinson's diseases. It is therefore important to understand the condition of the olfactory system. However, existing olfactory measurement techniques suffer from the problems of scents scattering in the air and measurements needing a lot of time and effort. In this study, we developed an olfactory measurement system that uses pulse ejection. Unlike existing olfactory measurement techniques, our olfactory display employing pulse ejection measures olfaction by changing the ejection quantity. We conducted an experiment that measured and quantified the human olfactory characteristics in precise detail in response to pulsed scents. The results reveal that people are able to sense extremely small quantities of scent. Measurements were finished in approximately 5 min and were influenced very little by lingering scent. In the future we aim to find a diagnostic threshold for smell disorders through measurements of more people and hope that screening by olfactory measurement will be implemented at health checkups and in hospitals.