When a population or group of something is declining, and the amount that decreases is proportional to the size of the population, it's called exponential decay. In exponential decay, the total value decreases but the proportion that leaves remains constant over time.
A ventriculoperitoneal (VP) shunt is a medical device that relieves pressure on the brain caused by fluid accumulation. VP shunting is a surgical procedure that primarily treats a condition called hydrocephalus. This condition occurs when excess cerebrospinal fluid (CSF) collects in the brainâs ventricles. CSF cushions your brain and protects it from injury inside your skull.
How It Works. A shunt usually consists of two catheters and a one-way valve. The valve regulates the amount, flow direction, and pressure of cerebrospinal fluid out of the brainâs ventricles. As the pressure of cerebrospinal fluid inside the brain increases, the one-way valve opens and the excessive fluid drains to the downstream cavity.