User's Manual

128
Handling and Implantation
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Sensor Gain
The sensor gain controls the change in pacing rate for a certain change
in workload detected by the sensor. An exercise test (such as walking)
is recommended in order to achieve a rate response proportional to
workload by optimizing the sensor gain. If the pacing rate is too high
for the specific amount of workload, the sensor gain should be
reduced. If the pacing rate is too low, a higher gain setting should be
selected. The sensor trend with rate forecast can be used to record the
pacing rate during exercise.
Additionally to the fixed sensor setting, an automatic sensor gain is
available.
Sensor Threshold
The sensor threshold controls the signal amplitude that has to be
exceeded to cause a rate increase. This parameter is meant to assure a
stable pacing rate at rest and to prevent rate increases at signal levels
not consistent with physical exertion.
The sensor threshold should be optimized after adjusting the sensor
gain.
If the patient does not have a stable pacing rate at rest, the sensor
threshold should be increased. If, however, the pacemaker tends to
respond only at higher workloads, a reduction of the sensor threshold
should be considered. The sensor trend with rate forecast can be used
to record the pacing rate during provocation tests.