Design and Construction of a Distributed Sensor NET for Biotelemetric Monitoring of Brain Energetic Metabolism using Microsensors and Biosensors

Neurochemical pathways involved in brain physiology or disease pathogenesis are mostly unknown either in physiological conditions or in neurodegenerative diseases. Nowadays the most frequent usage for biotelemetry is in medicine, in cardiac care units or step-down units in hospitals, even if virtually any physiological signal could be transmitted (FCC, 2000; Leuher, 1983; Zhou et al., 2002). In this chapter we present a wireless device connected with microsensors and biosensors capable to detect real-time variations in concentrations of important compounds present in central nervous system (CNS) and implicated in brain energetic metabolism (Bazzu et al., 2009; Calia et al., 2009). Molecular Oxygen (O2), an essential molecule for life, is utilized not only for cellular respiration but also for biosynthesis and metabolism of various important biomolecules such steroids, eicosanoids and neuroactive substances (Watanabe et al., 1997). It is also implicated in several biochemical reactions involving, for instance, ATP in the brain (Bazzu et al., 2009). To monitor istantaneous oxygen concentrations and relative variations could give important information about brain energetic metabolism related to glucose (Fillenz, 2005) or lactate consumption (Aubert et al., 2005). Eletrochemical reduction of oxygen is amperometrically obtained by means of complex transformations occurring at a carbonepoxy sensor surface by applying a potential of -400 mV vs Ag/AgCl reference electrode (RE) (Bazzu et al., 2009; Calia et al., 2009) as follows: