The fMRI-compatible patient response system.
The Lumina LP-400 is a patient response system designed specifically for use in an fMRI environment.
The system consists of several components including the pads, controller, and over 40 meters (140 feet) of cables.
Lumina was developed to satisfy the requirements of both the clinical and research fields.
It is compatible with many of the leading software packages on the market and interfaces easily with a number of third party hardware devices as well.
Lumina LP-400 specifications
 |
 |
|||
| In this article | ||||
 |
|
|
|
|
| Other information | ||
|
|
|
|
|
The Lumina LP-400 system includes two fiber optic response pads, each with two colored push buttons.
They are:
• Built of 100% plastic and fiber optic parts
• Magnetically and RF inert
• Water resistant
• Delivered with right hand and left hand versions
• Safe -- no laser lights are used
The pads come permanently connected to a unit called the OTEC via a 3 m (15 ft.) fiber optic cable.
This cable is protected by a sturdy crush resistant cover.
The OTEC is the unit that converts the electrical signals to light. It is housed in an aluminum enclosure and is typically installed under the magnet.
The picture above on the left shows the OTEC unit connected to the two response pads via the protected fiber optic cable. The picture on the right shows more details of the OTEC unit.
Il regolatore
The controller is where everything connects. The controller:
Powers the OTEC unit and detects input from the response pads
• Times the reaction time of the patient and provides other timing functions
• Accepts triggers from the MRI scanner via an optically isolated input (see below).
• Has lights with colors that match the push buttons to show when the patient has pressed a button
• Interacts with the host computer via the serial port
• Provides TTL input and output via the Accessory Connector.
Controller's Trigger Input
The controller features a scanner trigger input. Physically, this is a BNC connector (75 ohm). The minimum width of a trigger pulse is 300 microseconds and there must be at least 25 milliseconds between pulses when in XID mode at 9600 baud. This can be 12 milliseconds for all other modes and baud rates.
In optical isolation mode, the minimum voltage for an 'ON' is 1.5V or higher, and 'OFF' is 1.3V or lower (measured with pin positive with respect to the aluminum enclosure).
Cavi
Two shielded cables are included, each about 20 m (65 ft.) long.
The first cable is installed inside the magnet room. It has a circular connector that plugs into the OTEC unit on one end, and a DB9 male connector that plugs into a DB9 cutout on the MRI room's penetration panel.
The second cable has a DB9 female connector that plugs into the penetration panel from outside the magnet room, and a circular connector that plugs into the controller.
Other Components
The Lumina system comes with the following additional components:
• A filter for the penetration panel. This item is not normally included but is provided free of charge upon request. It is needed only if your penetration panel is not filtered already.
• A 9 volt A/C adapter.
• A serial port cable.
The most frequently asked question is how a Lumina system is installed. The following diagram gives an overview:
A - Response Pads: These are built of 100% plastic and fiber optics. They are totally inert and safe.
B - OTEC Unit: Converts electricity to light and is connected to the pads via protected fiber optic cables.
C - Shielded Cable: Connects the OTEC unit to the penetration panel. Uses wires and connectors of the highest quality.
D - RF Filter: Optionally installed if the penetration panel does not have a built-in filter.
E - Shielded Cable: Connects the penetration panel to the controller.
F - Controller: Detects key presses, times them, performs TTL I/O, and connects to the host computer.
G - Serial Cable: Connects the controller to the host computer.