There are nine kinds of acupuncture tools for different diseases in ancient China: Shear Needle (Chan Zhen), Round-pointed Needle (Yuan Zhen), Spoon Needle (Di Zhen), Lance Needle (Feng Zhen), Stiletto Needle (Pi Zhen), Round-sharp Needle (Yuan Li Zhen), Filiform Needle (Hao Zhen), Long Needle (Chang Zhen), and Big Needle (Da Zhen). Spiritual Pivot-Application of Needles (Chapter 7) says: The nine kinds of needles have different usages. They are either long, or short, or large, or small. They are used for different purposes. Most modern acupuncturists use filiform needles only and have almost discarded the other eight of Nine Classical Needles. In other words, they try to use filifrom needles only to treat different diseases, which is obviously impossible.

In 1968, a tomb in West Han Dynasty (202BC-8AD) was discovered in Mancheng, Hebei Province, China. Four gold and five silver needles were found and identified as tools for acupuncture in the early times. They are the earliest metal needles that have been discovered so far. Some of these needles were rusted and broken due to the long history and poor resistance against corrosion. The remains of these needles show the rough sizes of ancient needles, which have short shafts and long handles, with a length of 6.5-6.9 cm. The shafts are 1.5-4.3 in length and 1.5 in diameter. Limited by the producing techniques and the requirements (proper strength and tenacity) of acupuncture practice, the diameter of ancient needles was mostly about 1mm.

Due to the advances of materials and producing techniques as well as patients’ fear of pain, modern filiform needles are produced with a diameter of 0.25-0.3mm, which means an ancient acupuncture needle may be 3-5 times thicker than a modern one.

The efficacy of acupuncture is closely related to selected points and puncture needles.

The Annals of Three Kingdoms (San Guo Zhi) records that Huatuo was professional at treating pains. He selected points along both sides of the spine, which are named Huatuojiaji points, for back pain. In his practice, one or two points were punctured and needles were withdrawn as soon as qi arrived, then patients were cured.

Needles must be thick at Huatuo’s time due to the limitations of producing techniques. With thick needles, robust muscles at Huatuojiaji area in the back were dilated; the sticking tissues were separated; the effects of unblocking the meridians and stopping the pains were, thus, achieved.

In modern clinical practice, the same Huatuojiaji points are selected, but very few can remove the needles immediately after the arrival of qi and cure the diseases. This is probably associated with the fact that the thickness of needles has impacts on therapeutic effects. The universal use of filiform needles has been reducing the therapeutic effects.

Qihuang needle, 0.5 mm in diameter, was developed on the basis of twenty years clinical practice by Dr. Zhenhu Chen. It can not only be used as filiform needles, but also functions as Lance Needle (Feng Zhen) and Round-sharp Needle (Yuan Li Zhen) for pain management. It is considered as an improvement of acupuncture needles because it enjoys the advantages of several ancient classical needles and reduces impacts of needle thickness on therapeutic effects.