Cardiac Adapted Sleep Parameters Electrocardiogram Recorder (CASPER) examined the sleep patterns of International Space Station (ISS) and NASA Extreme Environment Mission Operations (NEEMO) crewmembers by monitoring heart rates and information provided in a questionnaire. This information was designed to help determine what might be causing any sleep disturbances and develop countermeasures.
CASPER combined objective physiological data and subjective inputs. Physiological data was obtained through a specially adapted vest, worn by the crewmember, with embedded sensors and cabling that connected electrocardiogram (ECG) electrodes, for measuring heart rate, to a PDA for storing the heart rate data. Subjective inputs were obtained via a questionnaire, which ran on the same PDA. A questionnaire was completed both prior to and after each sleep period that the heart rate was measured.
The data collected on these missions can help to establish and distinguish the reasons and patterns of astronaut sleep disruption and facilitate the development of relevant countermeasures to monitor and ensure astronaut sleep stability during long-term space flight.