With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: L.A. Law is a legal drama television series.
text_B: The photoplethysmogram -LRB- PPG -RRB- measurement made at a peripheral site , such as the finger , ear or forehead represents the volume of blood in the vessel at the site of measurement .. photoplethysmogram. photoplethysmogram. The PPG signal consists of pulses that reflect the change in vascular blood volume with each cardiac beat .. cardiac. cardiac. Beat-to-beat fluctuations , known as photoplethysmogram variability -LRB- PPGV -RRB- are found in the signal baseline and amplitude which reflects various physiological influences such as respiration and regulation of vascular tone by the sympathetic nervous system .. photoplethysmogram. photoplethysmogram. amplitude. amplitude. respiration. Respiration ( physiology )
not_related.