Physio-Control LIFEPAK 15 - Manual (Page 268)

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LIFEPAK 15 Monitor/Defibrillator Operating Instructions
Shock Advisory System
Motion Detection
The Shock Advisory System detects patient motion independent of ECG analysis. A motion detector
is designed into the LIFEPAK 15 monitor/defibrillator. MOTION DETECTION can be set up to be ON or
OFF . For more information, see the LIFEPAK 15 Monitor/Defibrillator Setup Options provided with
your device.
A number of activities can create motion, including CPR, rescuer movement, patient movement,
and some internal pacemakers. If variations in the transthoracic impedance signal exceed a
maximum limit, the Shock Advisory System determines that patient motion of some kind is present.
If motion is detected, the ECG analysis is inhibited. The operator is advised by a displayed
message, a voice prompt, and an audible alert. After 10 seconds, if motion is still present, the
motion alert stops and the analysis always proceeds to completion. This limits the delay in therapy
in situations where it may not be possible to stop the motion. However, the rescuer should remove
the source of motion whenever possible to minimize the chance of artifact in the ECG.
There are two reasons why ECG analysis is inhibited when the motion alert occurs, and why the
rescuer should remove the source of the motion whenever possible:
1. Such motion may cause artifact in the ECG signal. This artifact can cause a nonshockable ECG
rhythm to look like a shockable rhythm. For example, chest compressions during asystole can
look like shockable ventricular tachycardia. Artifact can also cause a shockable ECG rhythm to
look like a nonshockable rhythm. For example, chest compressions during ventricular fibrillation
can look like an organized, and therefore nonshockable, rhythm.
2. The motion may be caused by a rescuer’s interventions. To reduce the risk of inadvertently
shocking a rescuer, the motion alert prompts the rescuer to move away from the patient. This
will stop the motion and ECG analysis will proceed.