A portable and low-cost fMRI compatible pneumatic system for the investigation of the somatosensensory system in clinical and research environments.
There still is a need for devices that allow reproducible stimulation of skin areas of the human body. We constructed a stimulation system and tested it by using brief pneumatic stimulation to the right thumb of nine healthy volunteers. BOLD-signals in response to tactile stimulation with frequencies of 1, 3 and 5 Hz were measured using a 3T MRI scanner. The stimulation device consists of synthetic membranes connected to plastic tubes capable of carrying compressed air, and an electronic component, which controls the on- and off-switching of an electromagnetic valve. The valve near the MR-scanner did not lower the image quality. Primary somatosensory activation contralateral to the stimulation site was reliably detected in response to a stimulus magnitude of 3.5 bar in all volunteers. 1 Hz stimulation resulted in higher maximal percentage BOLD-signal changes. Our device is an easy-to-construct, low-cost and portable tool suitable for research and clinical environments. It permits passive non-painful stimulation relevant for clinical assessments and is also compatible with magnetoencephalography (MEG) and electroencephalography (EEG). In basic and clinical research, this device therefore contributes to meaningful comparisons between results obtained with different techniques.
Department of Psychology, University of Konstanz, Fach D25, D-78457 Konstanz, Germany, and Institute of Neuroradiology, University Hospital of Zurich, Switzerland.
Christian
C
Wienbruch
Victor
V
Candia
Jonas
J
Svensson
Raimund
R
Kleiser
Spyros S
SS
Kollias
D000328:Adult; D000388:Air; D001931:Brain Mapping / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D010812:Physical Stimulation; D011312:Pressure; D013003:Somatosensory Cortex / Q000503:physiopathology*