PPG Logger app for iPhone and iPad

PPG Logger is the first and only app that lets you record, plot and export not only heart rate, RR intervals, time and frequency domain Heart Rate Variability Features but also the PPG raw data.

HOW DOES IT WORK?
PPG Logger uses a technique called photoplethysmography (PPG for short), which consists in detecting changes in blood volume during a cardiac cycle, by illuminating the skin and measuring changes in light absorption. PPG has become quite a popular non-invasive method for extracting physiological measurements such as heart rate and oxygen saturation. However, most applications today focus simply on heart rate or respiration rate. On the contrary, PPG Logger can also accurately determine HRV features.

WHAT CAN YOU USE IT FOR?
PPG Logger can assess cardiac autonomic regulation through quantification of sinus rhythm variability. Since HRV aims at quantifying autonomic regulations, it can be used as marker of sympathetic or parasympathetic predominance, and therefore become relevant in many applications. In athletes for example heavy training is responsible for shifting the cardiac autonomic balance toward a predominance of the sympathetic over the parasympathetic drive, and HRV analysis attempts to quantify this shift. Other applications span from stress monitoring, assessment of pathological conditions and even emotional regulation during financial decision-making.

MAIN FEATURES:
- stores raw PPG data at 180 Hz
- extracts, plots, stores and exports heart rate, rr-intervals, time and frequency domain heart rate variability features (AVNN, SDNN, rMSSD, pNN50, LF, HF, LF/HF)
- configurable time window for feature extraction (30 seconds to 5 minutes)
- automatic RR-interval correction
- event annotation
- comparison between up to 3 recordings lets you get a better understanding of autonomic regulation and sympathetic/parasympathetic activity under different contexts in a glance
- data export/storage on iTunes and Dropbox (csv format, exports heart rates, rr intervals, events and computed features). Data export needs to be performed from the history -> recording view, by clicking on the export button (bottom left)

Find out more at this link: http://www.marcoaltini.com/2/post/2014/01/heart-rate-variability-using-the-phones-camera.html

The app requires iphones 5, 6 or later (all versions).