Sensor Based Saliva Gas Analysis for Rapid Non Invasive Disease Detection

Abstract

The increasing rates of prevalence of metabolic and gastrointestinal and chronic diseases have increased the need to have non-invasive and immediate diagnostic technologies. Conventional types of diagnostic modalities, based on blood sampling and laboratory tests, are often intrusive, lengthy, and depend on expert clinical facilities. Saliva has been recently seen as a pre-emerging biofluid as a promising non-invasive diagnostic biofluid due to a long list of biochemical and gaseous biomarkers that reflect systemic physiological conditions. In this study, a sensor-implemented saliva gas analysis system is proposed to identify the disease indicators through the quantification of the volatile gases released by saliva samples. The experimental subsystem incorporates sensors for methane, ammonia, oxygen, and conductivity in a closed examination chamber. These sensors record changes in gaseous levels of biomarkers that are related to the level of metabolic activity, fermentation by the microbes, and oxidative stress. The data analysis through statistical analysis indicated that there were significant differences in the concentration of gases among disease cohorts. Methane was most significantly separated in the statistic with an F-value of more than 4000, and ammonia and oxygen also showed high degrees of difference, above an F-value of $600(\mathbf{p}<\mathbf{1})$. On the other hand, salivary conductivity exhibited relative level change with a level of significance of p=0.03. The results are supportive of the fact that the salivary gas analysis can determine the presence of aberrant patterns of biomarkers in approximately 20 minutes of sample collection. In turn, the suggested system will provide a fast, non-invasive, and low-cost diagnostic method that may be utilized to enable portable point-of-care monitoring and preliminary disease detection in a clinical and remote care environment.