RESUMO
A retained surgical instrument is a frequent incident in medical surgery rooms all around the world, despite being considered an avoidable mistake. Hence, an automatic detection solution of the retained surgical instrument is desirable. In this paper, the use of millimeter waves at the 60 GHz band for surgical material RFID purposes is evaluated. An experimental procedure to assess the suitability of this frequency range for short distance communications with multiple obstacles was performed. Furthermore, an antenna suitable to be incorporated in surgical materials, such as sponges, is presented. The antenna's operation characteristics are evaluated as to determine if it is adequate for the studied application over the given frequency range, and under different operating conditions, such as varying sponge water content.