Monitor, Actigraph Activity

The LSLE Activity Monitor (Actigraph) is a wrist-worn instrument that records body motion. The device uses a piezoelectric sensor to detect zero crossings. The zero crossing counts are stored in a 64K RAM memory chip that uses an interface unit to a PC for initialization and memory download. The interface unit is not flight-qualified so the analysis and initialization is performed on the ground. Memory capacity depends on the data packing option selected. The number of counts stored during a time period or epoch is programmed pre-flight. The packing options are optimized for expected activity (awake or sleep), memory capacity and battery life. The unit is powered by two 160 mAH lithium cells powers. The actigraph uses a wristband made of Nomex and Velcro to meet flight material requirements and ease of attachment in microgravity.NASA transferred this monitor to the Museum in 2012.