The hippocampus pulse is not visible to the naked eye. The happy pulse is a common term in Chinese medicine and refers to the sensation of the pulsation of the radial artery on the forearm of the body near the thumb side of the palm root with the finger tip in the abdominal position during pulse diagnosis. In clinical practice, the happy pulse is also standardized as the slippery pulse, which feels like the sliding sensation of pearls rolling on a disc, and is experienced by using the index, middle and ring fingers to feel the pulsation of the radial artery, and therefore cannot be seen with the naked eye. Generally, if the embryo is well developed, the happy pulse is strong and the pulsation is more powerful; if the embryo is poorly developed, the happy pulse is weak and the pulsation is more feeble.