Een spier die beweegt wekt potentiaalveranderingen op. Dat geldt ook voor passief bewogen spieren, zoals beweging door aanraking.
rescue heeft wel gelijk als hij zegt dat grotere bewegingen nodig zijn om de beweging te kunnen registreren.
Ik heb op internet de technische handleiding van de lifepack 500 het volgende gevonden:
Motion Detection
The Shock Advisory System detects patient motion independent of ECG analysis. A motion detector is
designed into the LIFEPAK 500 AED. MOTION DETECTION can be configured in the setup mode to be ON
or OFF.
A number of activities can create motion, including CPR, rescuer movement, patient movement, vehicle
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:
• Such motion may cause artifact in the ECG signal. This artifact may occasionally cause the Shock
Advisory System to reach an incorrect decision.
• 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.
The motion detection feature can be set to OFF. When this option is off, analysis of the ECG is allowed to
proceed uninhibited even in the presence of motion, which may or may not cause artifact in the ECG as
described previously. Artifact in the ECG can sometimes cause an erroneous shock advisory decision.
The skill and training level of the care providers should be taken into consideration when deciding whether
or not to turn off the motion detection feature. How readily do the users respond to the AED voice
prompt? For example, do they immediately stop CPR upon hearing the STAND CLEAR, ANALYZING NOW
prompt?