Development of a simple MR-compatible vibrotactile stimulator using a planar-coil-type actuator.
For this study, we developed a magnetic resonance (MR)-compatible vibrotactile stimulator using a planar-coil-type actuator. The newly developed vibrotactile stimulator consists of three units: control unit, drive unit, and planar-coil-type actuator. The control unit controls frequency, intensity, time, and channel, and transfers the stimulation signals to the drive unit. The drive unit operates the planar-coil-type actuator in response to commands from the control unit. The planar-coil-type actuator, which uses a planar coil instead of conventional electric wire, generates vibrating stimulation through interaction of the current of the planar coil with the static magnetic field of the MR scanner. Even though the developed tactile stimulating system is small, simple, and inexpensive, it has a wide range of stimulation frequencies (20 ~ 400 Hz, at 40 levels) and stimulation intensities (0 ~ 7 V, at 256 levels). The stimulation intensity does not change due to frequency changes. Since the transient response time is a few microseconds, the stimulation time can be controlled on a scale of microseconds. In addition, this actuator has the advantages of providing highly repeatable stimulation, being durable, being able to assume various shapes, and having an adjustable contact area with the skin. The new stimulator operated stably in an MR environment without affecting the MR images. Using functional magnetic resonance imaging, we observed the brain activation changes resulting from stimulation frequency and intensity changes.
Department of Biomedical Engineering, Research Institute of Biomedical Engineering, College of Biomedical & Health Science, Konkuk University, 322 Danwol-dong, Chungju-si, Chungcheongbuk-do, 380-701, South Korea. hyungshikkim@gmail.com
Hyung-Sik
HS
Kim
Mi-Hyun
MH
Choi
Yoon-Gi
YG
Chung
Sung-Phil
SP
Kim
Jae-Hoon
JH
Jun
Jang-Yeon
JY
Park
Jeong-Han
JH
Yi
Jong-Rak
JR
Park
Dae-Woon
DW
Lim
Soon-Cheol
SC
Chung
D000328:Adult; D001921:Brain / Q000502:physiology; D004867:Equipment Design; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D019047:Phantoms, Imaging; D010812:Physical Stimulation / Q000295:instrumentation*; D014110:Touch / Q000502:physiology; D014732:Vibration