What are the AF, Normal and Unreadable Algorithms? - Medical Solutions Co., Ltd.

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What are the AF, Normal and Unreadable Algorithms?

AliveCor has developed multiple FDA-cleared detectors or algorithms. These detectors are only appropriate for use on Lead I.
The Normal detector will notify you when no abnormalities are detected by displaying the message “Normal. No abnormalities were detected in your EKG.” This means that your heart rate was between 50-100 beats per minute, there were no or very few abnormal beats, and the shape, timing and duration of each beat is considered normal. Remember that there is a wide range of “normal” variability among different individuals, so the Normal detector has been designed to be conservative. Also, if you have been diagnosed by a physician with a condition that affects the shape of your EKG, are experiencing an arrhythmia or took a poor quality recording, it is unlikely that you will be notified that your EKG is normal.

The Noise detector will notify you when the recording is “Unreadable” because the signal contains a clinically relevant amount of noise which is determined to not be an EKG. This can be caused by physical movement, dry skin, or other sources. To try to solve “Unreadable” results, try to relax and hold still, rest your arms or move to a quiet location.” Once you’ve made these changes you can go ahead and take another recording. Other best practices to get a high quality recording include:

  • Keep your Kardia electrodes clean using an alcohol-based sanitizer.
  • Apply a water-based lotion to your hands prior to taking an EKG recording if your hands are very dry.
  • Ensure your smartphone or tablet is not plugged in or charging during recording.

The AF detector will notify you to the presence of atrial fibrillation with 97% sensitivity and 98% specificity. If AF is detected, you will see the message “Possible AF Detected.” This result is not a diagnosis, only a possible finding. We recommend sending it AliveCor’s EKG analysis service for review, or sharing it with your doctor or medical professional.

Note that the EKG recording must be 30 seconds in length for the detectors to function.