At the heart of my novel - like a golden pulse - lies the concept of chi.

Chi has never been clinically established inside a laboratory and it is not a concept used in Western medicine. In China, however, it is different. Chi lies at the heart of traditional Chinese medicine and the codified Chinese acupuncture studies go back two thousand years.

The concept of vital energy informs The Emperor's Classic of Internal Medicine - the historical equivalent of the Western Corpus Hippocraticum.

Chi enters the body through acupuncture points and flows through twelve meridians and two midline collaterals and through paired yin and yang organs. The movement of chi builds up in wavelike movements, completing a cycle every twenty-four hours. In the early morning hours, chi is at its lowest ebb.

Although chi cannot be dissected under a microscope and does not fit the empirical model, many Western scientists have done experiments with acupuncture. Robert Becker, an American orthopaedic surgeon who specialises in biomedical electronics, found that there are electrical charges separate from the pulses of the body's nervous system, which correspond to the body's acupuncture meridians. Other scientists have proved that there are differences in the levels of potassium and sodium in acupuncture points compared to the surrounding tissue. Acupoints also exhibit lower skin resistance: these points conduct electrical current more efficiently. What's interesting is that this lower skin resistance is even measurable after death.

Chi and Reiki

In Keeper my heroine is a long distance Reiki practitioner who uses chi as a healing force to protect the fighters in her keep. The founder of Reiki is considered to be Usui Mikao (1865-1926) but it is worth remembering that the origin of healing through universal energy dates back before the time of Christ and Sammasambuddha. Fa gung - the transmission of chi through meditation -- is a very old concept.

Chi and martial arts

I believe in chi myself and I also think that we are all subliminally aware of each other's chi and react to it intuitively. Some among us are blessed with strong chi, in others vital energy is blocked and may lead to malaise and depression.

There is no place where I am more aware of my own vital energy than when I am training in the dojo. Increasing your chi sensitivity is central to the discipline of martial arts. For a beautifully written exposition of this journey I highly recommend Kenji Tokitsu's Ki and the Way of the Martial Arts.