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N H Saunders

Publications and source records attributed to N H Saunders.

5 recordsLinked to original sources
PubMed1997

The performance of an infra-red interactance instrument for assessing total body fat.

Infra-red interactance has been evaluated as a technique for measuring total body fat in comparison with a range of alternative methods. The alternative techniques employed were neutron activation analysis, tritiated water dilution, whole-body potassium-40 counting, skinfold anthropometry, bioelectrical impedance analysis and the body mass index. The study group consisted of 43 healthy adults (16 males and 27 females). For 11 women, measurements were obtained before and after 11 weeks on a very low-calorie diet, giving a total of 54 sets of data. Correlation coefficients between infra-red interactance and the other techniques varied between 0.58 (p < 0.0002) and 0.80 (p < 0.0001) for females, and between 0.64 (p < 0.009) and 0.94 (p < 0.0001) for males. The average fat for the study group was underestimated by 15% using infra-red interactance in comparison with the average fat obtained from the other techniques. It was also noted that the infra-red interactance instrument yielded a very narrow range of body fats in females in comparison with the other techniques. It is essential that these differences are reconciled before infra-red interactance takes a significant role in body composition analysis.

Adipose Tissue↗
PubMed1993

A feasibility study of in vivo electromagnetic imaging.

Over the last decade several non-invasive electromagnetic techniques to determine human body composition have been described, based primarily on the good discrimination in electrical conductivity between fat tissue and water-bearing fat-free tissue. As an extension of such work, carried out within the Swansea In Vivo Analysis Research Group, an electromagnetic system is described which has the potential to generate useful in vivo images of body structure. Preliminary experiments on this electromagnetic scanning imager, using simple saline phantoms as objects, are discussed. It is shown that objects with electrical conductivities corresponding to fat and fat-free tissue can be differentiated and that the internal and external geometry of simple objects can be sensed. Images are presented which have been generated by several image reconstruction techniques.

Diagnostic Imaging↗
PubMed1993

The composition of weight loss in dieting obese females by electrical methods.

The fat and fat-free components of the weight loss of a group of obese females undergoing a clinically monitored dieting regime have been estimated by two noninvasive electrical techniques, bioelectrical impedance analysis (BIA) and tissue resonance impedance monitoring (TRIM). These two procedures are described and results presented for a group of volunteers representing a wide range of body mass index. During the 11 weeks of the study the members of the group were on a 405 kcal liquid ketogenic diet. Within experimental error, the estimates of changes in body composition by the two methods agree with each other and also with estimates determined by tritiated water dilution and neutron activation measurements on the same group of subjects. The average loss in body mass was 16.2 kg, representing approximately 18% of the average initial body mass. The loss comprised about 20% fat-free tissue and 80% fat tissue. The safety, convenience and non-invasive nature of the electrical techniques makes them useful additional procedures to be deployed in the routine monitoring of body composition.

Adult↗