Bioelectrical applications

Electrochemical stability is an essential requirement for CPs designed for any long-term bioelectric applications. Cychc voltammetry (CV) is used to measure the electrochemical characteristics of a CP sample, including the reduction/oxidation potentials and reversibility. By performing CV over multiple cycles the long-term electrochemical stability of a sample can be assessed. This technique has been shown to be particularly important in the... 

Poly(chloro-p-xylylene) is suitable for its use in implantable, microfabricated devices [83]. It is hydro-phobic, with a low dielectric constant, and a good biocompatibility. However, for many bioelectrical applications, its poor wet adhesion may be a drawback. 

S.A. Jaffari and A.P.F. Turner, Novel hexacyanoferrate(III) modified graphite disc electrodes and their application in enzyme electrodes.1. Biosens. Bioelectr. 12,1—9 (1997). 

The rat skin TER assay enables to reliably discriminate between skin corrosives and noncorrosive substances [148], The assay relies on the change in the bioelectrical properties of the skin in response to the application of test chemicals. For the measurements, small discs of rat skin are necessary onto which the substances are applied to the epidermal surface for up to 24 h. In... 

The phenomenon of bioelectrical catalysis with direct electron transfer from electrode to enzyme active site was primarily observed in the study of electrochemical oxygen reduction in the presence of a copper-containing oxidase - laccase, adsorbed on electrodes of different origins. This work was developed with peroxidase and hydrogenase application as the working components [2],... 

Davis F. and Hingson S.P.J. (2007) Biofuel Cell, Recent Advances and Applications. Biosens. Bioelectr., 22, 1224-1235. 

Roubenoff R, Baumgartner RN, Harris TB, et al. Application of bioelectrical impedance analysis to elderly population. J Gerontol 1997 52A M129-M136. 

Castaneda, M.T., Merko i, A., Pumera, M. and Alegret, S. (2007) Electrochemical genosensors for biomedical applications based on gold nanoparticles. Biosen. Bioelectr. 22, 1961-1967... 

Sode K, Ohta S, Yanai Y, Yamazaki T (2003) Construction of a molecular imprinting catalyst using target analogue template and its application for an amperometric fructosylamine sensor. Biosens Bioelectr 18(12) 1485—1490... 

Malmivuo J. and Plonsey R. 1995. Bioelectromagnetism Principles and Applications of Bioelectric and Biomagnetic Fields. New York, Oxford University Press. 

This section provides an overview of numerical techniques which can be apphed to a class of bioelectric field problems. Bioelectric field problems are found in a wide variety of biomedical applications which range from single cells [1], to organs [2], up to models which incorporate partial to full human structures [3-5]. We describe some general modeling techniques which will be applicable, in part, to all the... 

The application program interface (API) to SClRun is the visual dataflow environment called the network editor. Within the network editor, programs can be visually assembled from the hbrary of available algorithms. The dataflow network for a sample bioelectric field simulation is shown in Figure 23.1. 

C.E. Miller and C.S. Henriquez. Finite element analysis of bioelectric phenomena. Crit. Rev. Biomed. Eng., 18 181-205,1990. This represents the first review paper on the use of the finite element method as applied to biomedical problems. As the authors note, bioengineers came to these methods only fairly recently, as compared to other engineers. It contains a good survey of applications. 

Y. Kim, J.B. Fahy, and B.J. Tupper. Optimal electrode designs for electrosurgery. IEEE Trans. Biomed. Eng., 33 845-853, 1986. This paper discusses an example of the modeling of bioelectric fields for applications in surgery. 

Y. Rudy and B.J. Messinger-Rapport. The inverse solution in electrocardiography solutions in terms of epicardial potentials. CRC Crit. Rev. Biomed. Eng., 16 215-268,1988. An excellent overview on the inverse problem in electrocardiography as well as a section on the application of the boundary element method to bioelectric field problems. 

C.R. Johnson and R.S. MacLeod. Nonuniform spatial mesh adaption using a posteriori error estimates applications to forward and inverse problems. Appl. Numer. Math., 14 331-326, 1994. This is a paper by the author which describes the apphcation of the h-method of mesh refinement for large scale two- and three-dimensional bioelectric field problems. 

Good overviews of biopotential electrodes are found in Geddes L. A. 1972. Electrodes and the Measurement of Bioelectric Events, New York, John Wiley 8c Sons and Ferris C.D. 1974. Introduction to Bioelectrodes, New York, Rlenum. Even though these references are more than 20 years old, they clearly cover the field, and httle has changed since these books were written. Overviews of biopotential electrodes are found in chapters of two works edited by John Webster. Chapter 5 of his textbook. Medical Instrumentation Application and Design, covers the material of this chapter in more detail, and there is a section on bioelectrodes in the Encyclopedia of Medical Devices and Instrumentation... 

The parameters of interest in body composition analysis (bioelectric impedance analysis, BIA) are (a) TBW, (b) extracellular/intracellular fluid balance, (c) muscle mass, and (d) fat mass. Application areas are as diversified as sports, medicine, nutrition, and fluid balance in renal dialysis and transplantations. 

The applications discussed above address the interaction between humans and biomedical products and systems that use embedded and connected information technologies. However, as HCI technology develops to address new paradigms, new modes of interaction (e.g., haptics, gestures, speech, bioelectric signals, and behaviometrics) will increasingly involve biomedical factors. 

Bioimmittance is measured in vivo or in vitro. The tissue may be kept alive and perfused under ex vivo conditions. Bioimmittance can be measured with two-, three- or four-electrode systems. With four electrodes, one electrode pair is current carrying and the other pair picks up the corresponding potential difference somewhere else in the tissue. If the measured voltage is divided by the applied current, the transfer impedance is calculated. If no voltage is measured, the transfer impedance is zero. This is equivalent to the bioelectricity case in which a signal from the source, such as the heart, is transferred to the skin surface electrodes. Zero transfer impedance does not mean the tissue conducts well, only that no signal transfer occurs. With the bioimpedance two-electrode technique, the transfer factor is eliminated because current application and signal pickup occur at the same site, which means that measured impedance reflects tissue electrical properties more directly. 

In this book, and in Chapter 10 in particular, we take a look at the many applications of bioimpedance and bioelectricity, including clinical, laboratory, borderline medical and nonmedical, nonmedical, and nonbiological applications. 

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