@ARTICLE\{IMM2011-06154,
    author       = "O. V. Olesen and R. R. Paulsen and L. H{\o}jgaard and B. Roed and R. Larsen",
    title        = "Motion Tracking for Medical Imaging: A Non-Visible Structured Light Tracking Approach",
    year         = "2011",
    keywords     = "Cameras , Face , Positron emission tomography , Surface reconstruction , Three dimensional displays , Tracking",
    journal      = "{IEEE} Transactions on Medical Imaging",
    volume       = "",
    editor       = "",
    number       = "",
    publisher    = "",
    note         = "{DOI} 10.1109/TMI.2011.2165157",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/6154-full.html",
    abstract     = "We present a system for head motion tracking in {3D} brain imaging. The system is based on facial surface reconstruction and tracking using a structured light (SL) scanning principle. The system is designed to fit into narrow {3D} medical scanner geometries limiting the field of view. It is tested in a clinical setting on the high resolution research tomograph (HRRT), Siemens {PET} scanner with a head phantom and volunteers. The {SL} system is compared to a commercial optical tracking system, the Polaris Vicra system, from {NDI} based on translatory and rotary ground truth motions of the head phantom. The accuracy of the systems was similar, with root-mean-square (RMS) errors of 0.09 . for 20 . axial rotations, and {RMS} errors of 0.24 mm for 25 mm translations. Tests were made using 1) a light emitting diode (LED) based miniaturized video projector, the Pico projector from Texas Instruments, and 2) a customized version of this projector replacing a visible light {LED} with a 850 nm near infrared {LED}. The latter system does not provide additional discomfort by visible light projection into the patientfs eyes. The main advantage over existing head motion tracking devices, including the Polaris Vicra system, is that it is not necessary to place markers on the patient. This provides a simpler workflow and eliminates uncertainties related to marker attachment and stability. We show proof of concept of a marker less tracking system especially designed for clinical use with promising results.",
    isbn_issn    = "0278-0062"
}