2.3.4.1 Annotated alarms

Since no large annotated dataset of alarms is publicly available, a set of gold standard alarms to support the development and testing of a false alarm suppression algorithm was generated from the above alarms. Initially we have concentrated on life-threatening arrhythmia alarms, namely; Asystole, Extreme Bradycardia, Extreme Tachycardia, Ventricular Tachycardia and Ventricular Fibrillation. In order to assemble such a database we first searched for patient records in the MIMIC II database that met the following two criteria:

1. Record contains at least one of the 5 above listed critical alarm categories.
2. At least one of the alarms is associated with simultaneous ABP and ECG waveforms.

Our initial search yielded 496 patient records with a total of 45,370 hours of simultaneous ECG & ABP waveforms containing 8,636 alarms. Each alarm was manually reviewed by two independent experts, and discrepancies were adjudicated by a third expert.

Alarm repetitions referring to the same event, were removed. Furthermore, all 48 patients that possessed active intra-aortic balloon pumps (IABP) were removed, since their ABP waveforms do not appear as ``physiologically normal''. The final set comprises 448 patients with 5,386 alarms with simultaneous ABP & ECG waveforms. These annotations have been posted on PhysioNet with the file extension .alM.

Full details of how these alarms were annotated is available in Aboukhalil et al (11), together with an evaluation of their statistics.