The human scanner that measures body fat

A new scanner that measures the composition of the body - and can potentially also provide relevant data for studies comparing and relating body shapes to health risks such as heart disease - is being developed.

A prototype scanner - designed and built by Lancaster University engineers and scientists at the Institute of Food Research, England - is fast, safe, non-invasive and should be relatively low-cost when manufactured for commercial use.

The scanner uses two imaging techniques to predict the amount of fat present by estimating both the volume and water content of the body. It measures the outer shape of the body and could estimate regional variations in composition such as fat distribution.

Dr Henri Tapp, from the Institute of Food Research explains: "Body composition is an indicator of an individual's nutritional status. It can be used to monitor child development, pregnancy and changes during diet and exercise regimes. In addition to clinical applications, our system could also become a feature of leisure centres, allowing clients to see how their shape and composition changes through exercise."

The specially designed scanning cubicle is fitted with digital cameras and light projectors to map the surface contours of the body, to give body volume. An array of coils is used to map the internal electrical conductivity, to give water content. The camera and coils are fitted to a sliding sensor ring, designed to scan the whole body as a series of horizontal slices.

Although the initial aim is to predict percentage fat content, the system could potentially also provide regional information. This includes estimates for individual body segments, or differentiating between surface and internal fat within the torso. The surface data also provides anthropometric measures of body shape, such as android (apple-shaped) and gynoid (pear-shaped) fat distributions. This could be clinically useful, for example, in epidemiological studies comparing and relating body shapes to health risks such as heart disease.

Traditional measurement methods are time-consuming and inconvenient. For example, calculating body volume involves repeatedly submerging an individual in water, while simultaneously estimating lung volume. Determining body water involves drinking isotope-labelled water and then waiting for this to mix evenly within the body.

The novel sensor also has an advantage over x-ray methods because it is non-ionising and therefore safe for repeated use. The system should be relatively low cost, due to a fall in prices of the key hardware components.

Dr Tony Peyton, from the Engineering Department of Lancaster University, said: "Our prototype has demonstrated the feasibility of adopting this approach. The next stage would be to develop a prototype system leading to clinical trials and validation of the technology which we hope to pursue with commercial partners."