12
accepted that the saturation percentage is unreliable on the steep
part (around 60 mm Hg) of the oxyhemoglobin dissociation curve.
2.6
Innovative features of the 500DL
The 500DL is designed to address and alleviate some of the above
problems by
1) Increasing the sensitivity of the sensor to allow user to measure
his/her SpO
2
levels and Pulse Rate (PR) even at low blood perfusion.
2) Using a self-adjusting smart spring system to fit user’s finger snugly
but not too tight as to impede blood flow.
3) Using soft, hypoallergenic medical grade silicone in the finger
chamber to minimize discomfort to user’s finger.
4) Using solid ABS plastic to block ambient light from reaching the
sensor so that the signal to background ratio and accuracy of
measurement is dramatically increased.