Actiwatch Spectrum System (Actiwatch Spectrum) - 11.18.15
The Actiwatch Spectrum is a waterproof, nonintrusive, sleep-wake monitor worn on the wrist of a crewmember. The device contains an accelerometer for measuring motion and color sensitive photodiodes (a photodetector capable of converting light into voltage) for monitoring ambient lighting. Together, these capabilities enable the Actiwatch Spectrum to be used to analyze circadian rhythms, sleep-wake patterns, and activity. Science Results for Everyone
Information Pending Facility Details
Suzanne McCollum, Johnson Space Center, Houston, TX, United States
NASA Johnson Space Center, Human Research Program, Houston, TX, United States
Philips Respironics, Inc., Bend, OR
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Human Exploration and Operations Mission Directorate (HEOMD)
ISS Expedition Duration
September 2010 - September 2015
Previous ISS Missions
- The Actiwatch Spectrum captures data on subject activity and the amount of ambient light to which the subject is exposed.
The Actiwatch Spectrum is a replacement for an older Actiwatch system and comes with the added capability to differentiate between multiple wavelengths or colors of ambient light across a broad spectrum (400-700 nm). The Actiwatch Spectrum also has the added capability to display time and function as a watch.
The Actiwatch Spectrum can be used to investigate a number of activities such as sleep quality, sleep onset, hyperactivity and other daily routines.
Integrated Cardiovascular (NASA):
- Used in the ambulatory monitoring portion of the experiment beginning with Increment 28. Activity data collected by the Actiwatch Spectrum was analyzed in conjunction with cardiovascular data from other devices to estimate the amount of work the crewmember’s heart performed on a daily basis.
Circadian Rhythms (ESA):
- Used to monitor daily activity and sleep for some sessions aboard the ISS.
Biological Rhythms 48 Hrs (JAXA):
- HRF Actiwatch Spectrum Dock used to configure JAXA-owned Actiwatch Spectrums for data collection and to download the data after completion.
- Used as a contingency replacement to ESA’s activity-monitoring Armband hardware.
Sleep ISS-12 (NASA):
- Used to monitor daily activity, light exposure, and sleep patterns throughout the ISS mission for participating crewmembers.
- Use of the Actiwatch Spectrum involves a small number of basic operations: initialization, data collection, downloading data and downlinking data.
- Initialization of the Actiwatch Spectrum involves configuring the hardware to start recording data at a specific sampling rate at a specific time.
- The period over which the Actiwatch Spectrum may be used to collect data depends on the sampling rate and is limited by the internal storage capacity of the device and battery life.
- Data collection using the Actiwatch Spectrum is very similar to wearing a standard wristwatch. Once the device has been initialized and begins collecting data, the user need merely wear it at the location specified by the experiment for which data is being collected.
- Downloading the Actiwatch Spectrum involves connecting the device to a reader plugged into a computer and transmitting the data from the Actiwatch Spectrum to the computer.
- Downlinking the data from the Actiwatch Spectrum is a matter of transmitting the data stored on the ISS servers to the science teams on the ground.
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