Measurement of stress hormones is a common objective method for assessment of mental stress. However, the stress of blood sampling alone may also increase stress hormone levels. In the present study, we sampled salivary biomarkers from healthy volunteers under noninvasive conditions and determined t

The relationship between salivary biomarkers and state-trait anxiety inventory score under mental arithmetic stress: a pilot study.

Hand-Held Monitor of Sympathetic Nervous System Using Salivary Amylase Activity and Its Validation by Driver Fatigue Assessment

Saliva is increasingly recognised as an attractive diagnostic fluid. The presence of various disease signalling salivary biomarkers that accurately reflect normal and disease states in humans and the sampling benefits compared to blood sampling are some of the reasons for this recognition. This explains the burgeoning research field in assay developments and technological advancements for the detection of various salivary biomarkers to improve clinical diagnosis, management, and treatment. This paper reviews the significance of salivary biomarkers for clinical diagnosis and therapeutic applications, with focus on the technologies and biosensing platforms that have been reported for screening these biomarkers.

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Saliva-Based Biosensors: Noninvasive Monitoring Tool for Clinical Diagnostics

In Japan, forest-air bathing and walking (shinrin-yoku) has been proposed as a health-facilitating activity in which people spend a short period of time in a forest environment. Initially, we examined the usefulness of salivary amylase activity as an indicator of an individual's stress levels in a forest environment. The circadian rhythm of salivary amylase activity was measured in healthy young male subjects under stress-free conditions. The salivary amylase activity remained relatively constant throughout the day. Salivary amylase activity was then measured before and after walking in both urban and forest environments using a hand-held monitor. Our results indicated that (i) the circadian rhythm fluctuations in salivary amylase activity were much smaller than the stressor-induced variations; (ii) salivary amylase activity was an excellent indicator of the changes in sympathetic nervous activity; and (iii) the forest was a good environment in which people could experience much less environment-derived stress.

https://journals.sagepub.com/doi/pdf/10.1177/147323000603400204

The effects of exercise in forest and urban environments on sympathetic nervous activity of normal young adults.

We have designed a stress management biofeedback mobile service for everyday use, aiding users to reflect on both positive and negative patterns in their behavior. To do so, we embarked on a complex multidisciplinary design journey, learning that: detrimental stress results from complex processes related to e.g. the subjective experience of being able to cope (or not) and can therefore not be measured and diagnosed solely as a bodily state. We learnt that it is difficult, sometimes impossible, to make a robust analysis of stress symptoms based on biosensors worn outside the laboratory environment they were designed for. We learnt that rather than trying to diagnose stress, it is better to mirror short-term stress reactions back to them, inviting their own interpretations and reflections. Finally, we identified several experiential qualities that such an interface should entail: ambiguity and openness to interpretation, interactive history of prior states, fluency and aliveness.

Mind the body!: designing a mobile stress management application encouraging personal reflection

Performance evaluation of salivary amylase activity monitor

The authors have been focusing on the activity of α-amylase in saliva (salivary amylase) with the aim of developing a simple quantitative measurement technique for monitor human stress. However, the measurement of enzymatic activity required a sufficiently large volume of substrate and the realization of quantification also required some mechanism to control reaction time. Moreover, a measurement method using saliva samples should have the merits of simplicity, the ability to yield instant results and the potential to be used any time. Based on this concept, a salivary amylase activity monitor consisting of the test strip, a salivary transcription device and an optical analyzer was fabricated. The calibration curve for the salivary amylase activity monitor obtained an R 2 value of 0.72. The monitor could be used for the analysis of salivary amylase activity. In order to evaluate the monitor, salivary amylase activity was measured using a videotape of corneal transplant surgery as a mental stressor. A significant difference between salivary amylase activity was recognized between the prestress, midstress and poststress periods, and it was confirmed that increasing or decreasing human stress level could be perceived as increases and decreases in salivary amylase activity.

Test-strip-type salivary amylase activity monitor and its evaluation

An object of the present invention is to provide a means for measuring amylase activity existing in biological samples such as saliva in a more convenient manner and is particularly to provide a means (reagent for measurement, method for measurement and apparatus) by which a sample containing high concentrations of amylase is measured. There has been found a means (reagent for measurement, method for measurement and apparatus), whereby amylase activity in an amylase sample having a high activity value can be quite conveniently measured by making an oligosaccharide substrate carry on a support in an enzymatic method for measuring amylase activity using a modified oligosacharide substrate, whereupon the present invention has been achieved.

Reagent, method and apparatus for measuring amylase activity

An object of the present invention is to provide a means for the measurement of amylase activity that exists in a biological sample such as saliva in a more convenient manner and particularly to provide a means (method and reagent) where a sample containing amylase in high concentration is directly measured without dilution. In the present invention, there has been found a method, which is an enzymatic method using a modified oligosaccharide substrate, comprising adding saccharide such as oligosaccharide that is competitive to the oligosaccharide substrate whereupon amylase activity in an amylase sample having a high activity value can be directly measured without dilution, and a result, the present invention has been achieved.

Reagent and method for measuring amylase

In order to realize a novel hand-held monitor of the sympathetic nervous system, we have developed an analytical systenm for salivary amylase activity (sAMY) using a dry-chemistry system named "salivary amylase monitor". The device to quantfy sAMY by the rate method was'completely automated *This method was made possible by the fabrication of a disposable test-strip equipped with built-in saliva collecting and reagent papers and an automatic saliva transfer mechanism. A total of one minute was enough to analyse the sAMY. Within a range of sAMY between 12.9 - 150.7 kU/1, the calibration curve for the monitor showed a coefficient with R2 = O.972 and coefficient of variation (CV) = 12.6%. The simultaneous repeatability showed within 10%. Moreover, it was demonstrated that (i) the effect of coexisting Protein on the accuracy is less than 5%, (ii) the life time of the test-strip was 1.5years. Thus, this study denmonstrated that the monitor might be used as a better index fbr psychological research.

Hiroshi Yoshida

Papers

Performance evaluation of salivary amylase activity monitor

Test-strip-type salivary amylase activity monitor and its evaluation

Reagent, method and apparatus for measuring amylase activity

Reagent and method for measuring amylase

Analysis of Accuracy of Salivary Amylase Monitor