Evaluation of Salivation Promotion by Odor, Pressure, and Thermal Stimulus for Designing Wearable Device to Increase Salivation

Abstract

Saliva is an important fluid related to the maintenance of oral and systemic health, and a decrease in saliva volume causes various adverse effects. Saliva volume should be increased to avoid the adverse effects caused by decreased saliva volume. One method to increase saliva volume is to use a wearable device daily. Wearable devices that increase saliva volume in daily life should have the following features: easy to put on and take off, automatic movement, and no need to put the device in the mouth. To the authors’ knowledge, no such device exists. Therefore, this study aims to design a wearable device that can increase saliva volume in daily life using stimulus. Several previous studies have shown that lemon odor, massage of the lower part of the jaw, and warming of the lower jaw can increase saliva volume. However, it is not known whether these three stimuli can increase saliva volume quickly and under any situation. Therefore, in this paper, we investigate suitable stimuli for increasing saliva volume under situations that may change the effect of the stimuli for the construction of a wearable device. First, we implemented a mask-type experimental wearable device that can provide odor, pressure, and thermal stimulus. Next, a questionnaire survey was administered to confirm the situations under which saliva volume decreases. The results of the questionnaire showed that saliva volume decreased after conversations, after exercise, and upon waking up. Therefore, we investigated which of the three stimuli increased saliva volume quickly under these three situations and the usual situation. The results show that an odor stimulus significantly increased saliva volume in all situations compared to other stimuli. Based on the experimental results, we propose an eyeglass-shaped device that can provide an odor stimulus. The odor stimulus of the proposed device also significantly increased saliva volume.

Keywords

• wearable computing
• healthcare
• saliva secretion
• oral environment