A STRUCTURED LIGHT SYSTEM FOR MEASURING WOUNDS

The lack of an accepted method of accurate and objective measurement o f wound dimensions is a major obstacle to the assessment of effective wound management regimes. This paper addresses the problems associated with wound measurements and introduces a new instrument based on the principle of coded structured light. The instrument projects a sequenc e of parallel stripes of light onto the surface of the lesion. These p atterns are observed by a video camera which is linked to a computer s ystem where the images can be stored and processed Using the positions of the focal points of the camera and the stripe projector, the compu ter calculates a three dimensional map of the observed scene by triang ulation. This map is then used to reconstruct the original, healthy sk irt surface by cubic spline interpolation. The area of the reconstruct ed surface is the area of the wound Irs volume is sandwiched between t he measured and the reconstructed surface. The system also calculates the depth and the circumference of the wound. The instrument measures the volume of the wound with a precision of about 5 per cent provided that the ratio of volume to area is greater than 4 mm.