Actiheart Guide to Getting Started 5.1.11 (Feb 2020)
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9.0 Summary of Recording, Reading and Analysis Options
Once a
Signal Test
has been successfully completed the collection of data can
then commence. It is important to choose the recording mode taking into account
what the data will be used for, both immediately and for any potential future
analysis. This section summarises both the physical recording capabilities of the
Actiheart 5, and the focus of the main operating modes of the software both for
configuration and analysis.
9.1 Actiheart 5
Recording Modes
The Actiheart 5 offers two internal recording modes:
Full Waveform
: This mode records the ECG waveform between the two ECG
pads on the chest, simultaneously with three-axis acceleration waveforms.
Recordings made with this mode are marked as “Ah5 Wave” in the list of
recordings.
IBI Mode
: This mode records the amplitudes and timings of each peak captured
in the ECG waveform, along with three-axis acceleration waveforms. The ECG
peak recording allows a visual representation of the ECG waveform to be given
and also produces more robust IBI results than simple device-beat-detection
algorithms.
Recordings made with this mode are marked as “Ah5 IBI” in the list of
recordings.
In both of these cases, the acceleration waveforms will consist of X, Y & Z axes
and may be recorded with sample rates of 25Hz, 50Hz or 100Hz. Note that the
exact acceleration sampling frequency will vary internally, but it is timestamped
alongside the ECG signal capture and interpolated as necessary for each
analysis window. The raw data exported as text from the Recording Details
window will show the timing for each raw sample rather than any interpolated
results.
For the Full Waveform mode, the ECG may be captured at 128Hz, 256Hz, 512Hz
or 1024Hz. In all cases, the analogue bandwidth is limited to ~55Hz, and the
analysis software will interpolate each IBI to 1ms resolution. For this reason, we
do not recommend the highest rate modes (particularly 1024Hz), unless you
have a specific need to interface to legacy software which cannot interpolate
waveforms.
In IBI mode, the ECG will be sampled at 256Hz. Peaks are detected in this data
and both their timing and amplitude recorded for processing later in the PC
software. Again, the timing of each IBI is interpolated to 1ms resolution.
9.2 Other Device
Recording Modes
The Actiheart 5 PC software can also be used to configure and record with
legacy Actiheart 4 devices and Actiwave Cardios. Both of those offer a range of
different recording capabilities. For more details consult the original
documentation delivered with your recording hardware.
The Actiheart 5 software will attempt to offer recording modes for each device
which are suited to the function you have selected from the main menu. In some
cases no suitable mode will be available for that device. For example, this will be
