BVP Headband Sensor for the NeXus-4, 10 & 16.  Blood Volume Pulse Sensor
This BVP sensor monitors the relative blood flow in the hands (fingers) with near infrared light. This method is also know as photoplethysmography. (PPG) From the pulse signal the software can compute the heart rate.  This sensor can be used to monitor HR, HRV (heart rate variability), bloodflow and pulse.

We also recommend: NeXus-4, NeXus-10, NeXus-16, BVP Finger Sensor