Photoplethysmogram (PPG) Acquisition Devices

The following wearable devices are suitable for acquiring PPG signals:

Device	Location	Signals	Data capture	Further details
Smartcare Pulse Oximeter	wrist with finger probe	dual-wavelength PPG	via Bluetooth	Designed to acquire raw red and infrared PPG signals (at 100 Hz). Requires real-time connection to an android device to capture data (a phone or tablet). We assessed the feasibility of using this device to acquire PPG data in daily life here.
Empatica E4	wriststrap	PPG, EDA, accel, temp	On-device storage or via Bluetooth	Large on-device storage (up to 60 hours). PPG sampled at 64 Hz.
PulseOn OHR Tracker	wristband	PPG, accel	On-device storage or via Bluetooth	Good on-device storage (around 14 hours in my testing). PPG sampled at 25 Hz. Commercialised by Maxim Integrated in their Max-Health-Band