There are multiple definitions:

1. respiratory therapy technician(English)

   • Pulmonology, Therapeutic approaches

2. reflection transit time(English)

   • time difference between forward and backward waves, usually based on pulse counter analysis of a single pulse waveform
   • AC, AIx, DBP, PCA, PWV, SBP, WSA
   • Hemodynamics, Signal analysis

3. Rett syndrome(English)

   • a rare neurodevelopmental disorder with a notable period of developmental regression following apparently normal initial development
   • MeCP2
   • Neuropathy
   • https://doi.org…ene.2021.620859