This live wallpaper with ECG waveforms changing based on battery level. The wallpaper cycles through ECG hearth rhythm of Normal Sinus, Ventricular Tachycardia, Ventricular fibrillation and Asystole when phone is on battery use with settings for each rhythm. As the phone charges the rhythm shown is Supraventricular Tachycardia.
Each waveform can be colored with a different color and triggered based on the battery level. You can also select the speed of the waveform along with a host of other settings. The app can be downloaded from Google Play - https://play.google.com/store/apps/details?id=com.androidrec.wallpaper.live.
The app can also be downloaded from Android Wallpapers.
Below are a few screenshots from the live wallpaper.