Tracking and analysis of human head motion during Guided fMRI motor tasks

Abstract

In this work, we studied human head motions during upper extremity motor task, conducted in functional magnetic resonance imaging (fMRI) studies. The experiments were performed on a mock up of the MRI bench. Three kinds of linear movements in the caudal-cranial, left-right and anterior-posterior directions, a reaching movement as well as single joint movements at shoulder, elbow and wrist, were investigated at three different speeds with the right arm. Optical markers tracked by a high-precision motion tracking system were used to detect head and arm movements. For each task, the head moved principally in the direction of right-caudal-posterior to left-cranial-anterior, parallel to the line from the right shoulder joint to the head. No principal rotation axis was observed. The translational and rotational head motions were 1.7 ~ 8.4 mm and 0.15deg ~ 0.96deg, respectively. We then applied a special head fixation to stabilize the head, and repeated all the experiments. The translational and rotational head motions were significantly suppressed by 78% and 73%, to the range of 0.3 ~ 2.4 mm and 0.04deg ~ 0.39deg. AAbstract In this work, we studied human head motions during upper extremity motor task, conducted in functional magnetic resonance imaging (fMRI) studies. The experiments were performed on a mock up of the MRI bench. Three kinds of linear movements in the caudal-cranial, left-right and anterior-posterior directions, a reaching movement as well as single joint movements at shoulder, elbow and wrist, were investigated at three different speeds with the right arm. Optical markers tracked by a high-precision motion tracking system were used to detect head and arm movements. For each task, the head moved principally in the direction of right-caudal-posterior to left-cranial-anterior, parallel to the line from the right shoulder joint to the head . No principal rotation axis was observed. The translational and rotational head motions were mm and , respectively. We then applied a special head fixation to stabilize the head, and repeated all the experiments. The translational and rotational head motions were significantly suppressed by 78% and 73%, to the range of mm and .

A Reliability Study on Brain Activation During Active and Passive Arm Movements Supported by an MRI-Compatible Robot

“…Maximal speed was saturated to 10 cm s when the force reached 30 N or beyond. For both, active and passive movements, low speed and smooth movements were selected to avoid head motion and potential moving artifacts in the images (Yu et al 2008(Yu et al , 2009. The dROM was approximately 16-20 cm depending on the body size of the individual subject.…”

fMRI assessment of upper extremity related brain activation with an MRI-compatible manipulandum

“…The maximal speed was saturated to 10 cm/s when the force reached 30 N or beyond. The low speed and smooth movements were used for both active and passive movements in order to avoid head motion, and thus, potential artifacts to brain images [6,11].…”