The Application Of Photoacoustic Imaging Technology In Accupuncture

Acupuncture has more than two thousand years of application history. The practice of Traditional Chinese Medicine(TCM) has proven that acupuncture can treat a variety of diseases. Experimental acupuncture rise in recent years, which involves new research methods and qualitative and quantitative results, is more persuasive than the empirical TCM. Nevertheless, the process of internationalization of acupuncture is still slow for the lack of theoretical basis and scientific explanation means. In order to promote the internationalization of acupuncture, a bridge connecting traditional medicine and modern medicine should be established, which enables the visualization of acupuncture and drives the development of its theory establishment, demonstration and clinical promotion.The current visualization tools for acupuncture involve functional magnetic resonance imaging, positron emission tomography, electroence-phalogram and magnetoence-phalogram. However they all have limitations. To my best knowledge, this article first proposes the application of a novel biomedical imaging technology-photoacoustic tomography(PAT) in acupuncture. Photoacoustic tomography technique integrates the high optical imaging contrast with high ultrasonic imaging resolution. Thus it has high sensitivity to tissue structural and functional information. Acupuncture mechanism is largely associated with the dynamic changes in brain function. Hence, the paper focuses on the application of PAT in functional brain imaging. By doing repetitive experiments, comparing the changes of cerebral blood flow before and after acupuncture of the experimental animal and using post- statistical analysis, this article proves the feasibility of PAT in studying acupuncture and shows the cerebral changes of blood flow after acupuncture in Yongquan. It tries to explain the mechanism of acupuncture from hemodynamics.This paper mainly emphasizes on the experimental study of photoacoustic tomography in brain imaging and acupuncture mechanism. The structure is as follows:1. Described the process of visualization research about acupuncture mechanism both at home and abroad in recent years. Then it analyzed the advantages and disadvantages of a variety of visualization tools in brain imaging and introduced a novel technology-photoacoustic imaging technology that has a comparative advantage. Its development was briefly presented and its application in brain imaging and related groundbreaking research were mainly discussed.2. Began with stating the optical and acoustic properties of biological tissue, this article explained the specific generation process of photoacoustic signal within the organization from three aspects, including the interaction of light and tissue, the ultrasound propagation characteristics within the organization and the photoacoustic signal generation mechanism. Then it derived photoacoustic wave equation and the solution based on Green Function;3. Study the ability of photoacoustic tomography system in brain imaging. Firstly the article introduced the hardware, working process and delay-sum algorithm used in image reconstruction of the laboratory PAT system. Second, it made simulation of soft tissue and cortical vascular model to demonstrate capacity of the system for structural and functional imaging. The in vitro brain imaging experiments showed that the system can distinguish cerebral blood vessels and the in vivo brain imaging proved that the system can be applied to the living animals. These studies laid the foundation for the study of acupuncture mechanism.4. Applied the PAT system to study the changes of blood flow in brain before and after acupuncture in three cases, including when the acupoint is Yongquan in the right hind paw, Yongquan in the left hind paw and Yongquan both in the right and left hind paw, respectively. The repetitive experimental data obtained in the experiments was testing by a statistical analysis method called hypothesis testing. Ultimately the feasibility of the PAT system was proved to be used in studying acupuncture mechanism This study provides a visual test criterion for acupuncture.