There are multiple definitions:

1. in vitro diagnostics(English)

   • tests which use blood, saliva, and other human samples to detect the presence or risk of certain diseases — a pillar of modern medicine
   • EDMA, IVDD, MDD, MDR, CLIA, IVCT, KOL, LDT
   • Diagnostics, Biomarker

2. intervertebral disc(English)

   • In general, the anterior and middle IVD heights are approximately 2–4 mm, whereas the posterior heights are approximately 2–3 mm, producing a general lordotic IVD shape along the cervical spine. Their lowest values are usually at C2–3 and T1–2
   • CEH, DDD, MnO2
   • Spine (or spinal cord), Anatomy, Headache
   • https://doi.org…598-021-98981-y