MW8 & MotionWare User Guide: Issue 1.2.1
Page 20
Recording Mode
The MotionWatch offers the following recording modes:
MotionWatch Mode 1
– This is an epoch based
recording mode designed to produce similar
behaviour to legacy Actiwatch and similar products,
using a single axis algorithm and peak detection.
Tri-Axial Mode 3
– This is an epoch based
recording mode that uses all three of the
accelerometer axes to produce a vector magnitude
result per epoch. This mode is used for recording
daytime activity when the watch can be mounted at
other locations on the body (See body position
below). Note that this mode will shorten the battery
life as there is more data processing.
Body Position
For daytime activity analysis it is recommended to note the
location upon the body where the MotionWatch is
mounted. The physical mounting position will have an
effect upon the data (e.g. data from the wrist will differ from
that recorded at the waist). This is an optional field that
does not affect the data processing.
Epoch
The epoch is the duration for which the MotionWatch will
accumulate samples before storing the result in memory.
For example, using a 1 minute epoch, one result will be
stored in memory every one minute. The MotionWatch
offers the following epoch length options:
1 Second
2 Seconds
5 Seconds
15 Seconds
30 Seconds
60 Seconds
Note
: the algorithms used for sleep analysis are validated
using a 30 second epoch.
Light Recording
The MotionWatch has a built in ambient light sensor. Light
recording may be enabled or disabled by checking or
unchecking the ‘Record light’ checkbox during setup.
When enabled the MotionWatch will store light values in
lux at the same epoch as the activity samples. The light
sensor records white light with a response optimised to
match the human eye. The light is sampled once per
second and averaged over the epoch. The results are
stored as lux values.
Recording Lengths
The MotionWatch calculates and displays the expected
recording length as the settings are changed. The
recording mode, epoch, light settings and compression will
