Tuesday, August 23, 2011

Engineering Explanations

Lately I have noticed my usual answers to the common questions "how does acupuncture work? I mean, what do the needles really do?" have not been working for the folks who want an explanation in 20 words or less. Although I provide excellent literature on theory, a few months ago I jettisoned my TCM explanation and shortened it to "the needle sensation helps direct the release and flow of endorphins to stimulate the body's self-healing processes." This seems to satisfy those who find things like Qi and meridians either too esoteric or too hippy dippy to accept as viable healthcare.

As it turns out, my simple explanation has evidence-based research to back it. The Columbia University electrical engineering department and University of Hong Kong medical faculty of the collaborated on a study published in the June 2011 issue of The European Journal of Physiology to explain how acupuncture works. Needling acupuncture points sends slow-moving acoustic waves into the muscles. This triggers a flow of calcium that interacts with white blood cells and produces endorphins which can relieve pain and nausea throughout the body. Accuracy and point selection are important. Correct placement generates a 6-8 centimeter wave whereas incorrect placement up to 1 centimeter generates only a 3-4 centimeter wave. This finding may help explain why sham acupuncture can have a therapeutic effect even if delivered via toothpick (as I have been saying as nauseam!).

Here is the abstract:
This article presents a novel model of acupuncture physiology based on cellular calcium activation by an acoustic shear wave (ASW) generated by the mechanical movement of the needle. An acupuncture needle was driven by a piezoelectric transducer at 100 Hz or below, and the ASW in human calf was imaged by magnetic resonance elastography. At the cell level, the ASW activated intracellular Ca2+ transients and oscillations in fibroblasts and endothelial, ventricular myocytes and neuronal PC-12 cells along with frequency–amplitude tuning and memory capabilities. Monitoring in vivo mammalian experiments with ASW, enhancement of endorphin in blood plasma and blocking by Gd3+ were observed; and increased Ca2+ fluorescence in mouse hind leg muscle was imaged by two-photon microscopy. In contrast with traditional acupuncture models, the signal source is derived from the total acoustic energy. ASW signaling makes use of the anisotropy of elasticity of tissues as its waveguides for transmission and that cell activation is not based on the nervous system.

Link to Study
10.1007/s00424-011-0993-7

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