Bioelectrical impedance

One of the main determinants of the number of subjects required to reach the desired statistical power is the precision of the measurement tool utilized. More precise measurements will reduce the number of subjects required. As an example, if a study is being conducted to assess the influence of a dietary supplement on body fat, several measurement tools could be used to assess this outcome. These tools range from low levels of cost and precision (e.g. skinfold measurements) to moderate levels (e.g. bioelectrical impedance) to high levels of cost and precision (dual x-ray absorptiometry - DXA). A study that uses skinfold measurements to measure the outcome will require many more subjects than one which employs DXA. Therefore, it is often less expensive in total to utilize a more expensive measurement tool, because the more precise tool will allow the study to have sufficient power with a smaller number of subjects. 

Anthropometric measurements are gross measurements of body cell mass used to evaluate LBM and fat stores. The most common measurements are weight, height, limb size (e.g., skinfold thickness and midarm muscle, wrist, and waist circumferences), and bioelectrical impedance analysis (BIA). 

Several methods are available to evaluate a patient s actual body composition rather than total body mass. Skin-fold measurement may be of value in evaluating subcutaneous adiposity (adipose tissue accumulation) proper technique is required for reliable results. Other anthropomorphic measurements such as bioelectrical impedance, dual-energy x-ray absorptiometry, and total body water immersion are also available.These last techniques are often of value in research studies, but it is clinically impractical to use them routinely (Elberg et al., 2004). 

Bioelectrical impedance. This technique involves connecting electrodes to the hands and feet and passing a mild electric current through the body. Most organs and tissues conduct the electric current, as they contain water and salts. However, adipose tissue contains only about 14% water, by weight, and does not readily conduct electricity. The results give an indication of total body fat. 

BEE basal energy expenditure BIA bioelectrical impedance analysis... 

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

Kyle UG, Genton L, Mentha G, et al. Reliable bioelectrical impedance analysis estimate of fat-free mass in liver, lung, and heart transplant patients. JPEN J Parenter Enteral Nutr 2001 25 45-51. 

BI bladder irritation bowel impaction bioelectric impedance... 

Lukaski, H.C.. Johnson, PF., Bolonchuk, W.W., and Lykken, G.I. (1985) Assessment of Fat-Free Mass Using Bioelectrical Impedance Measurements of the Human Body, Am. J. Clin. Nutr. 47,810-817. 

Svendsen, O.L., Haarbo, J., Heitmarm, BF., Gotfredsen, A., and Christiansen, C. (1991) Measurement of Body Fat in Elderly Subjects by Dual-Energy X-Ray Absorptiometry, Bioelectrical Impedance Analysis and Anthropometry, Am. J. Clin. Nutr. 53. im-n23. 

Nagano, M., Suita, S., and Yamanouchi, T. (2000) The Validity of Bioelectrical Impedance Phase Angle for Nutritional Assessment in Children. 7. Pediatr. Surg. 35.1035 1039. 

Scanferla, E., Landini, S., Fracasso, A., Morachiello, P, Righetto, F.,Toffoletto, P.P. and Bazzato, G. (1990) On-Line Bioelectric Impedance During Hemodialysis Monitoring of Body Fluids and Cell Membrane Status. Nephrol. Dial. Transplant Suppl. 1,167-170. 

Ott, M.,Fischer, H., Polat, H., Helm, E.B.,Frenz,M., Caspary, WF., and Lembcke, B. (1995) Bioelectrical Impedance Analysis as a Predictor of Survival in Patients with Human Immunodeficiency Virus Infection, J. Acquir. Immune Defic. Syndr. Hum. Retroviral. 9,20-25. 

VanderJagt, D.J., Okolo, S.N., Rabasa, A.I., and Glew, R.H. (2000) Bioelectrical Impedance Analysis of the Body Composition of Nigerian Children with Sickle Cell Disease, J. Trap. Pediatr. 46,67-72. 

Passadakis, P., Sud, K., Dutta, A,. Singhal, M., Pettit, J., Chatalalsingh, C., Thodis, E., Vargemezis, V., and Oreopou-los, D. (1999) Bioelectrical Impedance Analysis in the Evaluation of the Nutritional Status of Continuous Ambulatory Peritoneal Dialysis Patients, Adv. Perit. Dial. 15, 147-152. 

Toso, S., Piccoli, A., Gusella, M., Menon, D., Bononi, A., Crepaldi, G., and Ferrazzi, E. (2000) Altered Tissue Electric Properties in Lung Cancer Patients as Detected by Bioelectric Impedance Vector Analysis, AutriViow 16,120-124. 

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. 

Cornish BH, Thomas BJ, Ward LC. 1993. Improved prediction of extracellular and total body water using impedance loci generated by multiple frequency bioelectrical impedance analysis. Phys Med Biol 38, 337. 

Lukaski HC, Hall CB, Siders WA. 2007. Assessment of change in hydration in women during pregnancy and postpartum with bioelectrical impedance vectors. Nutrition 8,543-550. 

Patterson R. 1995. Bioelectric impedance measurement. In Bronzino JD (ed.) The Biomedical Engineering Handbook. Boca Raton, FL, CRC Press, 3rd edition, pp. 1223-1230. 

Sun SS, Chumlea WC, Heimsfield SB et al. 2003. Development of bioelectrical impedance analysis prediction equations for body composition with the use of a multicomponent model for use in epidemiological surveys. Am Clin Nutr 77,331-340. 

In addition to MLP based classifier the presented approach should be validated with other advanced classification techniques such as Support Vector Machine (SVM). The robustness should be further examined with more statistics and with data from real driving scenarios. Inspired by study in [15] driving impairment such as inebriation should be investigated by utilizing bioelectrical impedance with tetrapolar electrode method. Correlation study of bioelectrical impedance and human emotional state can be carried out thereafter. 

Miller, H.A., Harrison, D.C., 1974. Biomedical Electrode Technology. Theory and Practice. Acad. Press. Morucci, J.-R, Valentinuzzi, M.E., Rigaud, B., Felice, C.J., Chauveau, N., Marsili, P.-M., 1996. Bioelectrical impedance techniques in medicine. Crit. Rev. Biomed. Eng. 24, 223—681. 

Bogonez-Franco, P., Nescolarde, L., Bragos, R., Rosell-Ferrer, J., Yandiola, I., 2009. Measurement errors in multifrequency bioelectrical impedance analyzers with and without impedance electrode mismatch. 

Cornish, B.H., Thomas, BJ., Ward, L.C., 1993. Improved prediction of extracellular and total body water using impedance loci generated by multiple frequency bioelectrical impedance analysis. Phys. Med. Biol. 38, 337. Cornish, B.H., Jacobs, A., Thomas, BJ., Ward, L.C., 1999. Optimising electrode sites for segmental bioimpedance measurements. Physiol. Meas. 20, 241—250. 

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