Device Description
Until the development of the Smell Identification Test™, also known as the University of Pennsylvania Smell Identification Test (UPSIT), no convenient means for subjectively assessing smell function was generally available. By incorporating microencapsulation technology and sound psychometric principles into a simple test format, the Smell Identification Test™ filled this void. Although this test was initially designed to provide only a first-step olfactory “screening” function, it became quite clear early on that the test was much more broadly useful than first envisioned and had applicability in numerous clinical, laboratory, and industrial settings. Indeed, the Smell Identification Test™ was found to be more reliable and to correlate more closely in the clinical setting with patient complaints and other indices of dysfunction than more traditional threshold and suprathreshold psychophysical methods.
The Smell Identification Test consists of four envelope-sized booklets, each containing ten “scratch & sniff ” odorants. The odorants are embedded in 10- to 50-um urea-formaldehyde polymer microencap- sules fixed in a proprietary binder and positioned on brown strips at the bottom of the test booklets. The stimuli are released by scratching strips with a pencil tip in a standardized manner. Above each odorant strip is a multiple-choice question with four alternative responses. For example, one of the items reads: “This odor smells most like: a) chocolate; b) banana; c) onion; or d) fruit punch.” The test is forced-choice; i.e., the subject is required to mark one of the four alternatives even if no smell is perceived.