Inhoudsopgave
Advertenties
All 20 second segments together led to a total number of 1187 ECG signals in the nonshockable
group and 200 ECG signals in the shockable group. These ECG segments were fed through to the
device and the recognition decisions on rhythm analysis were recorded through the voice prompts.
Figure 1: ECG-signals prepared for Test
According to the standard
• A true positive (A) is a correct classification of a shockable rhythm.
• A true negative (D) is a correct classification of all rhythms for which a shock is not indicated.
• A false positive (B) is an organized or perfusing rhythm or asystole that has been incorrectly
classified as a shockable rhythm.
• A false negative (C) is a VF or VT associated with cardiac arrest that has been incorrectly classified
as non-shockable.
The sensitivity of the device for shockable rhythms is A / (A+C)
The true predictive value is expressed as A / (A+B)
The specificity of the device for non-shockable rhythms is D / (B+D)
The false positive rate is expressed as B / (B+D)
c. Test results
The results of the tests are shown in the tables below:
True Positives (A)
192
Specifity
1161 / (1161+26) x
100%
= 97,8%
d. Conclusion
Sensitivity and specificity comply with all requirements set by IEC/EN 60601-2-4 and ANSI/AAMI
DF80.
False Positives (B)
26
Sensitivity
192 / (192 + 8) x 100%
= 96%
False Negatives (C)
8
True predictive value
192 / (192 + 26) x
100%
= 88%
53
True Negatives (D)
1161
False positive rate
26 / (26 + 1161) x
100%
= 2,2%
Advertenties
Inhoudsopgave
