Vein bursting is a common condition. I would recommend that you discuss this with your doctor as it may be a a sign of an underlying disorder that requires treatment. First of all, everyone occasionally experiences veins bursting. This results in an ecchymosis, or a bruise.
Couplings & Flexible Shafts. Couplings are devices used to connect two shafts together and are divided into two categories: Rigid and Flexible. Both are used for the purpose of transmitting power, rigid couplings being more limited in applications as compared to flexible couplings.
coupling interval the length of time between an ectopic beat and the sinus beat preceding it; in an arrhythmia characterized by such beats, the intervals may be constant (fixed coupling i's) or inconstant (variable coupling i's) .