A measurement is the topmost object in libRASCH. Figure 2 shows the
elements of the measurement. They contain
one or more recording sessions, information about the measurement object
(e.g. name, forename and birthday) and general informations about the
measurement. Additionally, evaluations are stored in the measurement.
Figure 2: Structure of a measurement in libRASCH.
A Session (see figure 2, middle part) is a recording for a specific
time interval without any interruptions during that time
interval. The measurement can contain more than one recording
session, but the layout of the recording (see below) must not be
A recording contains the measured data (e.g. ECG leads V1-V6)
or two or more sub recordings (in the figure 2, 'rec 0' has two
sub recordings ('rec 1' and 'rec 2')). Sub recordings are used if more than one
recording device is used. For example when one ADC-system records
3 ECG leads and one blood pressure channel and another system
records 12 eeg leeds, the measurement consists of one top
recording with two sub recordings. The first sub recording
contains 4 channels (3 ECG and 1 blood pressure channel) and the second
sub recording contains 12 channels (12 eeg channels).
The channels of sub recordings are mapped to the parent
recording. This allows the access to all channels through the top
most recording. The top most recording appears to be one device,
which measures all the data. In the above example, this means that
'rec 0' contains 16 channels: 3 ECG, 1 blood pressure and 12 eeg