CARDIAC ADAPTED SLEEP PARAMETERS ELECTROCARDIOGRAM RECORDER (CASPER)
Research Area: Human Behavior and Performance
Expedition(s): 14
Principal Investigator(s): ● Marc O’Griofa, University College, Dublin, Ireland
RESEARCH OBJECTIVES
Sleep deprivation can detrimentally affect mission success and crew member performance. The
effects are often compounded by the isolation, confinement, and the lack of normal
psychosocial interactions on space missions. Cardiac Adapted Sleep Parameters
Electrocardiogram Recorder (CASPER) investigates the use of cardiopulmonary coupling (CPC)
as a surrogate marker for sleep stability in comparison to a variety of other traditional markers
of sleep and circadian rhythm disruption in extreme environments. The two primary study
measurements are a single lead electrocardiogram and a subjective sleep diary that was
completed both pre-sleep and post-sleep.
SPACE APPLICATION
CASPER also resulted in the development of a non-contact, non-invasive, state-of-the-art Radio
Frequency Impedance Interrogation (RFII) hemodynamic monitor. The chest-mounted unit is
worn on various missions as a technology demonstrator and in conjunction with traditional
electrocardiogram (ECG) to correlate both signals.
Both the peak and period of the RFII signal are used
for analysis as the signal results from hemodynamic
motion as opposed to cardiac autonomic activity.
The RFII signal and data correlate significantly in
both the low- and high-frequency spectrums against
both CPC and traditional ECG HRV. Preliminary
research is also completed using the RFII signal for
unique subject identification.
EARTH APPLICATION
The results and technology development from
CASPER and this research create groundbreaking
advancements and remove many of the
impediments involved in the monitoring of
physiology and performance in extreme operational
environments ranging from spaceflight to remote
habitats on Earth.RESULTS
CASPER showed the effective use of CPC in a variety
of extreme operational environments by
demonstrating the strong correlation between traditional ECG heart rate variability (HRV) and
CPC high-frequency components across all missions. In contrast there was a weak correlation
between ECG HRV and CPC low-frequency components across all missions. This was
ESA astronaut Thomas Reiter wears the
Cardiac Adapted Sleep Parameters
Electrocardiogram Recorder vest right before
going to sleep. ESA image.