Bioelectrical parameters of the whole human body obtained through bioelectrical impedance analysis

Abstract

Knowledge of electrical properties of body tissues across the frequency spectrum is useful for tissue characterization. The bioelectric impedance analysis method, operating from 1 to 250 kHz (multi-frequency), was used in 23 normal male human subjects between the ages of 21 and 52 years, for estimation of their bioelectrical parameters. Amplitude of the output current was set to 800 microA(RMS). The experimental data showed that bioelectric parameters were highly dependent on frequency and the presence of a threshold frequency around 4 kHz. In order to explain the unusual features observed in our experimental data, the human body was simulated through the Cole-Fricke-Cole model (RC circuit) and the Extended Cole-Fricke-Cole model (RLC circuit). The simulated data showed that the Extended Cole-Fricke-Cole model had a higher accuracy than the traditional Cole-Fricke-Cole model. These results suggest that the unusual features could be due to the possible existence of inductive effects in biological cells and body tissues and that the inductive parameter and the threshold frequency could be used for characterizing the healthy tissues as well as the traditional bioelectric parameters.

Blood Impedance Characterization from Pulsatile Measurements

“…The inductive effect in curves Z d (f ) and Z s (f ), corresponding to the sub-ripple on the high frequency end (Fig. 4(a)), can be observed in many real measurements even on homogenous tissue [9]. This is alleviated in the pulsatile curve in which, although there still has a extension to negative part of imaginary axis at high frequency, it can be regarded as extrapolation of the Cole-Cole curve without affecting Cole parameters' fitting accuracy.…”

“…fitted in a ECFC model [9]. The Spice simulated data and the fitted data are denoted as x and solid lines, respectively.…”

Bioelectrical Parameters of People Exposed to Radiofrequency in Workplace and Houses Provided to Workers

“…the application of the bioelectric impedance analysis (BiA) method is growing in popularity because it is safe, noninvasive, rapid, portable, inexpensive, easy to use, and amenable for laboratory, clinical, and field assessment of human body composition. Recently, great advances were made in the art of accurately measuring the electrical properties of matter (14). However, giving the definition of some BIA parameters such as resistance, reactance, phase angle, body capacitance and basal metabolic rate would help to understand physics of BiA.…”

Bioimpedance Measurement in the Kidney Disease Patient

“…In Cartesian form this gives Z = R + jX where R is the resistance, X is the reactance, both expressed in Ohms, and j the imaginary unit, j = 1  Setting Z = 22 RX  and  = arctg (X/R) gives the polar form Z = Z e j  The bioelectric impedance Z describes the inertia of a biological medium opposing passage of a sinusoidal current with intensity I and pulsation  (rad/s). Along the lines of the electrical current, this impedance generates a difference of potential U. Bioelectrical impedance can be represented in a complex plane.…”

“…Many different instruments have been marketed using algorithms based on different equations predicting body composition from impedance measurements [22,23,24,25]. The validity of these different equations remains a question of debate since most have been established empirically.…”