**5. Summary**

In summary, there is a great potential for micro- and nanosensors' integration into healthcare monitoring devices, developing new technologies for noninvasive detection of diseases in the human body. Flexible wearable devices offer promising capabilities in real-time monitoring of body fluids including tear, sweat, and saliva. However, more research is required to expand the use of wearable platforms in continuous analysis of body fluids, providing reliable real-time detection of targeting ions and proteins, among other complex analytes.

**7**

**Author details**

Noushin Nasiri

Sydney, NSW, Australia

School of Engineering, Faculty of Science and Engineering, Macquarie University,

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*Address all correspondence to: noushin.nasiri@mq.edu.au

provided the original work is properly cited.

*Introductory Chapter: Wearable Technologies for Healthcare Monitoring*

*DOI: http://dx.doi.org/10.5772/intechopen.89297*

*Introductory Chapter: Wearable Technologies for Healthcare Monitoring DOI: http://dx.doi.org/10.5772/intechopen.89297*

*Wearable Devices - The Big Wave of Innovation*

detection of glucose over a range of 5–1000 μmol L<sup>−</sup><sup>1</sup>

ing ions and proteins, among other complex analytes.

Saliva, as a great diagnostic fluid, can be used in personal health devices for realtime monitoring of chemical markers including salivary lactate analysis [33]. Chai et al. developed a saliva nanosensor with a radio-frequency identification tag, integrated into dental implants for detecting cardiac biomarkers in saliva and predicting close heart attack in patients suffering from cardiovascular diseases [34]. In another approach, an instrumented mouthguard was designed and fabricated by Kim et al. [35] for measuring salivary uric acid levels which could be a biomarker for several diseases including hyperuricemia, gout, physical stress, and renal syndrome. The fabricated device showed high selectivity and sensitivity to low level of uric acid as well as great stability during a 4-h operation period [35]. Mannoor et al. [36] developed a hybrid biosensor made of graphene layers printed onto water-soluble silk, for noninvasive detection of bacteria through body fluids including sweat and saliva. This graphene/silk hybrid device illustrated an extremely high sensitivity to bacteria in body fluid with detection limits down to a single bacterium [36]. In addition, the fabricated device provided the potential users with battery-free operation and wireless communication system via radio frequency [36]. Arakawa et al. [37] designed and fabricated a salivary sensor equipped with a wireless measurement system, embedded onto a mouthguard support, featuring a high sensitivity toward

great stability during a 5-h real-time glucose monitoring period in an artificial saliva with a phantom jaw [37]. In a similar approach, de Castro et al. [38] developed a microfluidic paper-based device integrated into a mouthguard, for continues monitoring of glucose and nitrite in human saliva. The saliva samples were collected from periodontitis and/or diabetes patients as well as healthy individuals. The

In summary, there is a great potential for micro- and nanosensors' integration into healthcare monitoring devices, developing new technologies for noninvasive detection of diseases in the human body. Flexible wearable devices offer promising capabilities in real-time monitoring of body fluids including tear, sweat, and saliva. However, more research is required to expand the use of wearable platforms in continuous analysis of body fluids, providing reliable real-time detection of target-

fabricated device featured a low detection limit of 27 and 7 μmol L<sup>−</sup><sup>1</sup>

. The device demonstrated a

for glucose and

**4. Saliva analysis**

nitrite, respectively [38].

**5. Summary**

**6**
