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Theory of Operation
The ACT continuous ECG cellular phone and arrhythmia detector
consists of a chest-worn ECG sensor ("sensor") with electrodes and
a cellular phone with proprietary ACT cellular phone software. The
sensor records the ECG data and transmits the ECG signals via
Bluetooth to the cellular phone. The sensor also detects pacemaker
pulse and transmits a pacemaker flag to the cellular phone.
The sensor periodically measures the electrodes to body
impedance and transmits the measured values to the cellular
phone. The impedance test occurs every two minutes. During the
impedance test, ECG recording cannot be performed. The
impedance test session takes two seconds, and is performed once
every two minutes.
Notes
A short Pause episode which takes place
during, immediately before, or right after an
impedance check, might not trigger a
physiological alarm.
The cellular phone monitors the data by an incorporated algorithm
for the detection of certain arrhythmias. A detected arrhythmia
event triggers transmission, accompanied by the cardiac
arrhythmia type, a time stamp, and the raw ECG data to a
monitoring center for analysis. The cellular phone sends the end
time of the physiological event (pause event in whole) when the
algorithm has detected that the event is not active.
The sensor can store internally six (6) hours of ECG data, in order
to support Bluetooth link disconnections (due to interferences or the
patient moving out of the Bluetooth range). The cellular phone
stores the ECG data in the internal memory (not applicable for CEM
mode) for a period of up to 30 days.