Acupuncture, a major treatment method in TCM(Traditional Chinese Medicine), becomes an alternative method for treating p

1. Dept. of Medical Engineering Graduate School of East-West Medical Science Power Supply Magnetic Probes Transfer Capacitor Discharge Capacitor Switching Circuit Driver Introduction Acupuncture by Magnetic Stimulations Controller & Driver • Acupuncture, a major treatment method in TCM(Traditional Chinese Medicine), becomes an alternative method for treating pains in western medicine. • Electro-acupuncture techniques have been widely used in TCM for more efficient treatments. • Acupuncture needles, essential tools for both traditional and electro acupunctures, are very invasive and occasionally unacceptable to very weak patients or children. • We introduce a magnetic acupuncture system with which needle-less acupuncture therapy can be performed • By applying a very strong magnetic pulse at the vicinity of the human skin, we can induce electric current inside the human body. • The induced eddy current has been utilized to stimulate central or peripheral nerves in western medicine.[1] • By using specially designed stimulating coils, we can stimulate acupuncture (meridian) points in a non-invasive manner. Probes <Fig. 3> The magnetic acupuncture system • To generate very strong magnetic fields up to several tesla, we have used a capacitor charge/discharge technique. Advantages of Magnetic Acupuncture The magnetic acupuncture method has some advantages over other acupuncture methods. <Fig. 1> Meridians and acupuncture points <Fig. 4> The magnetic coil driving circuit Probe Current Magnetic Probe • To feed electric current into discharge capacitors with a small capacity power supply, we have used transfer capacitors. During non-stimulating intervals, the power supply charges the transfer capacitors. After then, the electric charge is transferred to the discharge capacitors.(See fig.5) • After multiple charge transfers from the transfer capacitors to the discharge capacitors, the voltage of the discharge capacitor rises up to 2 KV. • The switching components are high speed SCRs Eddy Current Configuration of the Magnetic Acupuncture System Acupuncture Point • The system is composed of three major parts. • Magnetic acupuncture probes to generate time-varying magnetic fields • A driving circuit to feed electric current to the probes • A control circuit to generate timing signals <Fig. 2> Eddy current induced by an external magnetic coil

2. Dept. of Medical Engineering Graduate School of East-West Medical Science 0.7 B [T] 0.6 z = -2mm 0.5 0.4 z = -5mm 0.3 z = -10mm 0.2 0.1 0 0 1 2 3 4 5 6 7 8 9 10 x [cm] Design of Magnetic Acupuncture Probes • In fig. 9, the magnetic flux densities along the x-axis at several z-values are shown. 6kV Transfer Capacitor Voltage • To stimulate acupuncture points efficiently, small sized loop coils are preferable. • It is very difficult to cool the small sized loop coils. • In this study, we have used a large loop coil with a magnetic core along the central axis of the loop coil, as shown in fig. 7. Time 250ms 2kV Discharge Capacitor Voltage Time 20ms ~ 1s (1Hz ~ 50Hz) 200ms 2kA Acupuncture Coil Current z z Time y Magnetic core (m=20000m0) Coil x <Fig. 5> Timing diagrams to control the driving circuit <Fig. 9> The magnetic flux densities along the x-axis 2.5mm 32.5mm 5mm 80mm • Maximum pulsing frequency •  50 Hz • Maximum voltage of the discharge capacitor •  2 kV • Capacitance of the discharge capacitor •  100 mF • Inductance of the magnetic coils •  30 ~ 40 mH • Number of pulsing channels  4 channels x 10mm Conclusions <Fig.7> A schematic diagram of the magnetic acupuncture probe • The developed magnetic acupuncture system gives the localized stimulation similarly to the conventional electro acupuncture. • Clinical tests will be performed very soon in a Korean traditional medicine hospital and a Chinese traditional medicine hospital. • The magnetic acupuncture system is expected to become a complementary tool to the conventional acupuncture techniques. • Using a commercial FEM tool, we have analyzed the spatial distribution of the magnetic field produced by the magnetic acupuncture probe. • In fig. 8, the magnetic flux density of the probe is shown. z [cm] References • [1] M.J.R. Polson, A.T. Barker, and I.L. Freeston, "Stimulation of nerve trunks with time varying magnetic fields", Med. Biol. Eng. Comput., Vol. 20, pp.243-244, 1982 <Fig. 6> A photograph of the developed system <Fig. 8.> Magnetic flux density produced by the magnetic acupuncture probe