Send to

Choose Destination
See comment in PubMed Commons below
IEEE Trans Med Imaging. 1997 Feb;16(1):17-27.

A head motion measurement system suitable for emission computed tomography.

Author information

Biomedical Engineering and Instrumentation Program, National Institutes of Health, Bethesda, MD 20892, USA.


Subject motion during brain imaging studies can adversely affect the images through loss of resolution and other artifacts related to movement. We have developed and tested a device to measure head motion externally in real-time during emission computed tomographic (ECT) brain imaging studies, to be used eventually to correct ECT data for that motion. The system is based on optical triangulation of three miniature lights affixed to the patient's head and viewed by two position-sensitive detectors. The computer-controlled device converts the three sets of lamp positions into rotational and translational coordinates every 0.7 seconds. When compared against a mechanical test fixture, the optical system was found to be linear and accurate with minimal crosstalk between the coordinates. In a study of two subjects, comparing the angular motions measured by the optical device and a commercially available electromagnetic motion detector, the two systems agreed well, with an root mean square (rms) difference of less than 0.6 degree for all rotations.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for IEEE Engineering in Medicine and Biology Society
    Loading ...
    Support Center