Arousal meter project
A computer system today receives no data regarding the physiological
or cognitive state of the user, but there are many cases where these
data could be useful.
For example, as the user becomes bored or lethargic, the system could
raise the workload or audio-visual feedback to stimulate arousal.
As the user becomes tense or strained, the system could lighten the
workload or simplify the feedback to lessen arousal. This type of
physiological-based closed-loop feedback could be applied in a
number of scenarios, such as driving, training, stressful repetitive
work (e.g. air-traffic control), and military operations.
In this project we have built a monitoring device that produces a
real-time cardiac-based measure of physiological arousal.
The measure is based upon changes in respiratory sinus arrhythmia,
an established measure of vagal activity.
The monitor provides the computing system with information about
the physiological state of the user.
Papers about this project:
A. Hoover, A. Singh, S. Fishel-Brown and E. Muth,
Real-time detection of workload changes using heart rate variability,
Biomedical Signal Processing and Control, vol 7 no 4, 2012, pp. 333-341.
J. Rand, A. Hoover, S. Fishel, J. Moss, J. Pappas and E. Muth,
Real-Time Correcton of Heart Interbeat Intervals,
in IEEE Trans. on Biomedical Engineering, vol. 54, 2007, pp. 946-950.
E. Muth, A. Kruse, A. Hoover and D. Schmorrow,
"'Augmented Cognition: Aiding the Soldier in High and
Low Workload Environments through Closed-Loop Human-Machine Interactions",
in Military Life: The Psychology of Serving in Peace and Combat,
edited by T. Britt, C. Castro and A. Adler, Praeger Security
Int'l Publishing, 2006, pp. 108-127.
S. Fishel, E. Muth, and A. Hoover,
Establishing appropriate physiological baseline procedures for
real-time physiological measurement,
in Journal of Cognitive Engineering and Decision Making,
vol. 1 no. 3, 2007, pp. 286-308.
A. Hoover and E. Muth,
A Real-Time Index of Vagal Activity,
International Journal of Human-Computer Interaction,
vol. 17, no. 2, 2004, pp. 197-209.
S. Fishel, J. Owens, E. Muth, A. Hoover and J. Rand,
"Augmented cognition: Developing and testing a physiology-based
task adaptation system",
in the proceedings of Human Factors and Ergonomics Society's
48th Annual Meeting, New Orleans, LA, October 2004.
L. Yu, A. Hoover and E. Muth,
"Detection of Human Physiological State Change Using Fisher's
Linear Discriminant", in the proc. of HCI International 2005.
E. Muth, A. Hoover and M. Loughry,
"Developing an Augmented Cognition Sensor for the Operational
Environment: The Wearable Arousal Meter", in the proc.
of HCI International 2005.
J. Rand, A. Hoover, J. Pappas, J. Moss, S. Fishel and E. Muth,
"Real-time correction of heart interbeat interval data",
in the proc. of Biomonitoring for Physiological and Cognitive
Performance during Military Operations, SPIE vol. 5797,
edited by J. Caldwell and N. Wesensten, 2005, pp. 63-70.
S. Fishel, E. Muth, A. Hoover and L. Gugerty,
"Determining the Resolution of a Real-Time Arousal Gauge",
SPIE, vol. 6218, June 2006.
The latest version of the desktop arousal meter software is
version 2.5b. Source code is available
Recent version upgrades made the following changes:
Version 2.3. Added Kalman filter for smoothing output.
Version 2.4. Added real-time IBI error detection and correction.
Version 2.5. Added various graphical displays (e.g. baloon)
for non-numerical feedback.
Version 2.5b. Updated to connect to EZ-IBI2, which sends data synchronously
instead of asynchronously.
We have created a tool (
IBIedit) for viewing and manual editing of IBI recordings.
AViewer tool allows viewing and comparison of arousal files,
along with simulatenous viewing of synchronous IBI traces.
In order to use our software, a heartbeat detector is required.
We recommend using the latest version of the EZ-IBI, available from
We have worked closely with UFI over the past few years to integrate
our software closely with their hardware.
They also sell a completely self-contained hardware arousal meter
(the wearable arousal meter, or WAM),
that embeds our software into their hardware.
Contact UFI for more details.
Last updated December 2012
AMeter Project Page / Clemson / email@example.com