Until a few years ago, pulse wave velocity in experimental animals (mice, rats, rabbits, etc.) could only be measured by invasive methods. The carotid or femoral artery was surgically isolated and catheterized to assess intra-arterial pressure. The carotid and femoral signals were measured simultaneously, and the pulse wave transit time was then calculated. However, this operation would cause the death of the small laboratory animal, which was then dissected to measure the distance between the two catheters. Pulse wave velocity was calculated in this way.