Body Composition Analyzer Based on PGNAA Method

Determination of the elemental compositions of a human body is a useful tool for understanding general physiology relationships, diagnosing some disease and cancers. Measurements of body composition yield data about normal growth, maturity and the process of ageing. Practically, these measurements provide standards against which departures from normality may be judged. It is necessary to define differences between genetic groups, the sexes within each group, the systematic variations with age and body size and the distribution of the seemingly random differences between individuals that remain unexplained. Knowledge of the range of normality is of value in studying trends in disease processes and monitoring the response to treatment. Body composition data may influence the choice of the most appropriate treatment of wasting illness, sepsis, trauma, renal failure and nutritional disorders. So many experimental methods employed in the measurement of the composition of the human body over the past 50 years and in the consequence a lot of techniques have been applied to determine the weight percentage of body chemical compositions. Early methods such as hydrodensitometry and skinfold anthropometry have been superseded by dual-energy x-ray absorptiometry and bioelectrical impedance spectroscopy. Also x-ray fluorescence can give important information of clinical significance. The relatively simple, rapid and risk-free electrical methods such as multifrequency bioelectrical impedance analysis, which can be employed at the bedside, have been found to be more complicated in their interpretation. Electromagnetic methods may only measure the composition of the human body at its surface. X-ray computed tomography and magnetic resonance imaging have not yet been employed much in body composition measurements. One of the non-destructive and the most sensitive approaches is Prompt Gamma Neutron Activation Analysis (PGNAA) method (Miri & Panjeh, 2007, Chichester, 2004, Metwally, 2004) but neutron activation facilities in practice remain available in only a few centers worldwide. In this method the sample is excited with neutrons. When an atom in the sample captures a neutron, that atom is transformed to another nuclear state of the same element. The new atom can be radioactive. If it decays with a short half life the radioactive signal can be