An Italian research institute has developed a mathematical means for rendering the sculptured surface of the human body on a computer screen and calculating its volume, which has enabled its medical researchers to study the body at work, according to Italian business journal Il Sole 24 Ore. The Milan-based Centre of Bioengineering Polytechnic and Pro Juventute Foundation combines expertise in advanced microelectronics and information systems expertise with neuroscientific and physiological research, as well as in clinical applications for various medical disciplines, says Antonio Pedotti, director of the centre. The system provides all the views of the body surface while calculating the volume that the surface contains. One of the applications, which demonstrates how the different thoracic muscular strata contribute to respiration, has been presented at the ninth international congress of the International Society of Electrophysiological Kinesiology in Florence. The program is based on a tetrahedral model of the thoracic cavity, which was written for this purpose by the centre’s researchers, explains Pedotti. It enables us, for the first time, to quantify the variations in volume of the three strata, the superior thoracic, middle and abdominal.
Marks of light on the skin
In other words, it means being able to estimate for the first time how these zones take part in respiration. In constructing the model of the human body, a person’s back, for example, is scanned with a low-power infrared laser. Every 15mS, at regular distances, the marks of light on the skin are simultaneously shown in their different positions by means of one or more pairs of telecameras. The images taken are elaborated upon by a parallel, dedicated system that comprises bioengineering, microelectronic and artificial intelligence components. The system is characterised by a two-level architecture: the first recognizes, on the basis of their form, the spots of light on the skin. At the second level, a Silicon Graphics Inc processor acquires the co-ordinates of the light spot and computes its position. A C-based program enables the user to reconstruct the surface of the body by means of a triangulation technique: the sides of the triangles unite adjacent points. The software calculates, point by point, the luminosity within each triangle and softens the contrast between the contiguous ones in a way implies continuity of surface. The resolution can be as high as desired; it is necessary only to increase the number of light spots and, consequently, the number of triangles. When it isn’t necessary to achieve a detailed resolution that distinguishes shadow and light, the reconstruction of the image can be realised by means of the Cardinal-spline method, rather than with triangles. This method uses mosaic surface interpolations, in which each piece can assume different positions with respect to those adjacent, without losing any continuity in the surface. The respiration application has shown that, in healthy individuals, the three strata work in almost equal measure and in perfect synchronisation. In someone with dystrophy, however, after an initial normal breath, the lowest stratum’s movement is missing suddenly, while the other two continue working. In someone with a vertebral inflammation, it can be seen that the top stratum is virtually absent, with little help from the middle stratum, so almost all of the work in respiration is being done by the abdominal stratum.
