Photogrammetric methods for acquiring accurate head surfaces for optical tomography monitoring of newborn infants

Three-dimensional optical imaging of the brains of newborn infants requires precise knowledge of the head surface and optode positions. Photogrammetric techniques are being developed in order to obtain these parameters with more precision than conventional methods which rely on generic head shapes and mechanical probing. Improvements in easurement precision will result in optical images with better quality in order to help in clinical diagnosis. Clinically ill infants represent a novel and challenging subject, since that the main requirements are a non-contact and non-invasive technique, which will not interfere with the normal treatment in the clinic. Whilst commercial systems are in use for facial mapping, the specific challenge is to determine the level of accuracy required and to develop robust and versatile tools which can be employed on newborn and severely ill infants in an intensive care environment, to measure not only the head surface, under varying amounts of hair, but also the optical fiber alignment to the head.