The Meridian DPA was given 510(k) clearance by the FDA in 2002.
The 501(k) number is K023238 (click here to view) and the approval states:
Device Name McPulse Photoelectric Plethysmograph [The original name of the Meridian DPA and still showing in the software window at startup].
Indications for Use: The device provides non-invasive measurement of the pulse waveform and heart rate by photoelectric plethysmography.