I haven't used but Sleepimage seems to collect detailed data. I don't think it is good for diagnosing sleep apnea.
The SleepImage CPC technology uses electrocardiogram (ECG) and accelerometer data to measure the effects of the sympathetic and parasympathetic nervous systems to determine sleep quality, objectively and accurately.
What is CPC? CPC is an algorithm that uses mathematical analysis to determine the synchronization between modulations of heart rate variability and respiration. The algorithm calculates the percent of stable sleep, presented as high frequency coupling (HFC), unstable sleep, presented as low frequency coupling (LFC) and wake/rapid eye movement, presented as very low frequency coupling (VLFC) in their respective spectral bands. Oscillations between stable and unstable sleep are expected within an intact system to modulate in 30 – 90 minute infra radian cycles that range from 5 – 16 cycles in an 8-hour sleep period and correspond to the alternating periods of non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. Disease states negatively impact this rhythm.
