ETIOGENESIS – D.I.P. Digital Imaging Plethysmography

The concept and development of digital imaging originated from a lecture at the University of Siena (Tuscany) in a specialized clinical nutrition course for physicians. Whilst waiting for the physicians to get seated and with the lecture hall light dimmed, I noticed that the light at the entry door was modulating in proportion to the size of the individuals passing through the area of the door opening. Specifically, wide-bodied individuals blocked more background light than smaller ones. Voila, the concept emerged that body surface, size, and shape directly affected the relationship between background and silhouette in a fixed area!

The proportion (%) of an object (individual or silhouette of an individual) filling a frame (doorway) of known dimensions, could be exploited to estimate (measure) its surface/volume, regardless of the distance between an observer and the frame.

I soon conducted a pilot experiment using an early digital camera model. The resolution was rather low, using pixels as coarse as bricks, nevertheless, the present occupation was strongly correlated with the body mass index (BMI) of everyone.

I manufactured a small series of wooden cabinets that included a computer-controlled rotating platform on the floor. The stepping motor would halt at consecutive 45° rotations and a digital image was obtained. Everyone underwent a body composition assessment with a BIA phase-sensitive impedance device that was at that time manufactured by my company. Rotation and sequenced pictures were originally purported to compute body volume, which is associated with weight to obtain density and thereafter, body composition.

After >50 male and female adults were observed, I soon realized that Body Density (BD) was as innovative as dinosaurs and that a better predictive projection for body composition assessment was the lateral digital image.

In collaboration with local Institutes such as Dr. A. Polito (INRAN -Rome), Dr. N. Di Lorenzo (University of Tor Vergata-Rome), and Dr. Jordan Moon (University of Oklahoma), we conducted a multiple-site study to validate this novel digital image body volume estimating approach.

Tony Talluri