products are meant only as a sample to show what other researchers have needed.
Eye Tracking Camera
More analysis possibilities are available when you know how your
subject is paying attention. MD&E
offers a hardware solution to capture video of the eye during fMRI
acquisition. The eyetracker camera
does not interfere with the subject's view of the stimulus screen,
and works in total darkness.
Video collected via this eyetracking camera: eye_moving.avi
(25MB)
Still pictures of eye tracking: eye1.jpg
eye2.jpg
eye3.jpg
- Joystick
- A joystick is useful for many different feedback experiments. Any common computer
- interface or signal output can be accommodated. This fMRI version uses copper wires and
- carefully selected analog circuitry to avoid interference with the scanner.
- There have also been "MEG versions" of this joystick made
- that contain no metal at all in the joystick itself. All of the signal I/O is accomplished
- with fiber optics.
X-ray Tube Holder
This is a good example of MD&E's ability to custom fabricate
acrylic shapes. This device is
designed to hold an x-ray tube near the MR bore. The slides
and pivots allow
the tube to translate in three dimensions and rotate in one dimension.
Tactile Stimuli
Going beyond the basic auditory and visual stimuli is becoming increasingly
common among fMRI
researchers. Using pneumatically powered pistons, MD&E
is able to create completely safe
and effective devices to physically stimulate the subject.
Pneumatic pistons can provide stimulate at a maximum of a few
Hz. This piezoelectric
device was designed to be operated by MIDI commands and responds
as fast as the
computer can issue commands. The device could also be controlled
by a programmable
oscillator or custom computer program. The stimulator holds a finger
or toe similarly
to an ECG clip.
Response Pad
The most basic need for an fMRI researcher is to have the subject
reliably respond
to stimuli in the scanner. The subject's comfort is sometimes
overlooked, and this has
two bad effects. One: the subject fatigues sooner and
must take more breaks. Two: the
collected responses may become inaccurate as the subject's fingers
tire. The "button box" shown
below is designed to be completely MRI-safe and extremely comfortable
for long periods of use.
The distance from the wrist cushion to the buttons is adjustable,
as is the angle of the buttons. The design
is also extremely durable, and adaptable for use with many stimuli-presentation
programs.
Head Restraints
Whether you are collecting fMRI data or structural data, having
the subject's head stay
still is of the utmost importance. In order to achieve sharp
MR images, and to maintain the subject's
comfort for long scans, a wide array of head restraints have been
developed and built. Each application
requires a slightly different design. For example, fMRI researchers
may need to have an area
clear for mirror placement, while oddly-shaped headcoils may require
a different arrangement.
