Basic concepts of optical measuring of bone thickness with IR-beam

This paper describes a new concept for measuring bone thickness via optically analyzing of hard tissue. In many surgical disciplines effecting bone treatment, like oral and maxillofacial surgery or otolaryngology, the knowledge of existing bone material is very important in order not to hurt anatomically sensitive structures. The existing bone material can be determined preoperatively using imaging procedures. However, the surgeon has no information about the residual bone thickness during the intervention. As a consequence of this, the distance between the tip of his instrument and sensitive structures is also unknown. Therefore, it would be very useful, if the bone thickness could be measured concurrently to the bone ablation. In this work, bone was irradiated with IR-Light and the reflection was detected. It would be examined, if there was an interrelation between bone thickness and reflection and how it could be measured. The results of the experiments show, that by means of this method it is possible to detect different bone thicknesses for a bone thickness < 1 mm.