Black Box IEEE 1284 Betriebsanweisung PDF herunterladen (Seite 50)

Page 50 of 98 The Black Box Toolkit

In the example shown, line 1 is the simulated fMRI pulse produced by BBTK No 1. Line 2

shows audio detected coming from the headphones of the remote PC. Line 3 shows the

properties of the image displayed on the remote PC. Line 5 shows the response made on

the BBTK response pad. By using the measurement cursors you can obtain exact

millisecond timing between two events on any line.

Note: If you wish to use the toolkit in a scanner room you will need to contact us to discuss

options for sensors as the standard kit is not suitable for use in a live MRI environment.

8.4. Digital stimulus capture and response (DSCAR)

DSCAR combines the features of the EG and DSC modules to provide four input and four

output lines. A bank of simulated responses can be setup with between one and four lines

being defined as active during each response. A set of trigger event(s) can then be defined

which need to be detected before a response with known timing characteristics is

simulated and fed into a remote PC. You are free to alter the delay after detecting any

trigger event(s) and vary the duration of the response as you see fit. This is the essence of

the notion of a virtual human.

DSCAR can be used to check both stimulus and response timings with sub-millisecond

accuracy. By comparing what was recorded this gives you the opportunity to fine tune the

paradigm to improve presentation and response timing accuracy.

DSCAR is actually made up of two programs. The first is used to define the characteristics

of the “virtual human”. That is, which events will be reacted to and what responses will be

simulated. The second is used to run the sequences that have been designed. The best

way to illustrate the use of DSCAR is with a simple worked example. A more expansive

tutorial is given in the case study section where the effect of using various response

devices is examined in terms of presentation and response timing error.

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Black Box IEEE 1284 Betriebsanweisung Seite 50