Stimulated oxygen transport in tissue by magnetic needle acupuncture

Aim To understand physiology of magnetic needle acupuncture by investigating O 2 transport in tissue during needle intervention. Methods O 2 transport in tissue is modeled by utilizing COMSOL with magnetic needle inserted into muscle tissue in a 2D porous media. The damaged tissue has been mimicked by an extracted tissue block with 1 st order O 2 consumption rate. The convection-diffusion O 2 transport in the damaged tissue has been further evaluated by varying magnetic flux density B 0 of the needle (0-1 T), myoglobin concentration (0-1 mM), O 2 tension (5-100 Torr), O 2 consumption rates, tissue permeability (10 −12 -10 −6 m 2 ) and porosity (0.1-0.9). Results 1) Active O 2 transport carried by interstitial flow is enhanced with the intervention of a magnetic needle by generating a high gradient magnetic field around the tip, which exerts a strong force (10 4 N/m 3 ) on the diamagnetic interstitial fluid to accelerate the flow. 2) This interstitial flow can reach 30 μm/s at B 0 = 1T and strongly correlates to the needle B 0 and tissue permeability. 3) The needle stirs the interstitial flow can pump O 2 flux by 1-2 orders of magnitude compared to that without magnetic field. 4) The enhancement of active O 2 transport by magnetic needle is site-specific to the tissue in the vicinity of the tip. This enhancement is more effective in edema condition with a high tissue permeability (>10 −9 m 2 ). Conclusions The dramatic enhancement of O 2 transport to restore the O 2 mitochondria metabolism for dysfunctional muscle tissues is the fundamental physiological mechanism of magnetic needle acupuncture.