Datascope Passport - Mindray

Arrhythmia Algorithm (Optional Passport 2) Operation
3.8 Arrhythmia Algorithm (Optional Passport 2)
The Passport 2 uses an arrhythmia algorithm to monitor ECG waveform data. The
algorithm creates ECG waveform templates based on a patient’s normal ECG data and uses
them to analyze newly received data. The algorithm verifies that data is free from noise and
artifact, and that it does not deviate from the patient’s normal ECG rhythms.
A normal ECG waveform typically includes consistent spacing between R waves, a sharp
and well defined QRS complex, and an ECG baseline that is free of noise and artifact.
P
ISO Point
Q
FIGURE 3-16 Sample Waveform
Noise and Artifact
R
ST deviation
(Depression or Elevation)
S
J Point
The presence of noise or artifact in an ECG waveform makes the accurate detection and
classification of heart beats difficult. To best optimize performance, all leads should be free
of noise.
Some of the causes of ECG noise include poor skin preparation, improperly attached
electrodes, dried electrode gel, defective leadwires, and patient movement. The algorithm
uses several techniques to differentiate a patient’s QRS complexes from noise sources.
If noise levels are too high, the following will occur until the signal quality is re-established:
Beat detection is suspended
All rhythm calls are suspended
An ECG Noise message is displayed when ECG noise is detected in one or more ECG
leads. If ECG noise continues beyond the configured noise delay, an alarm is triggered,
and ECG rhythm analysis is stopped.
3 - 34 0070-10-0649-01 Passport 2 ® /Passport 2 LT Operating Instructions
ST Point
ST Segment
T
40 to 80 msec