There are multiple definitions:

1. powerline interference(English)

   • BPF, ECG
   • Electrophysiology, Bioengineering

2. power loss index(English)

3. professional liability insurance(English)

   • a form of liability insurance that helps protect professional advice- and service-providing individuals
   • AMA, CMS, RBRVS
   • Health insurance, Care giver/provider
   • https://www.va.…enefits/PLI.asp

4. pulmonary leak index(English)

   • used to measure pulmonary permeability
   • ALI, ARDS
   • Pulmonology
   • https://dx.doi.…crc.2009.02.009

5. phase locking index(English)

   • HRV, SUDEP, TLE
   • Epilepsy or syncope

6. phase-lag index(English)

   • PLV, PS
   • Signal analysis
   • https://doi.org…hum.2022.799881

7. polarized light imaging(English)

   • 3D-PLI
   • Photonics, Imaging
   • https://doi.org…155/2012/412512