Transcript PowerPoint 프레젠테이션

Dept. of Medical Engineering
Graduate School of East-West Medical Science
Introduction
Acupuncture by Magnetic Stimulations
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.
Advantages of Magnetic Acupuncture
The magnetic acupuncture method has
some advantages over other acupuncture
methods.
NonContinuously
invasive ? stimulating ?
<Fig. 1> Meridians and acupuncture points
Probe
Current
Magnetic
Probe
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.
Power
Supply
Magnetic
Probes
Controllability
of stimulating
strength
Transfer
Capacitor
Traditional
needle
acupuncture
No
Electro
acupuncture
No
No
Discharge
Capacitor
No
Switching
Circuit Driver
Yes
Yes
<Fig. 4> The magnetic coil driving circuit
Magnetic
acupuncture
Yes
Yes
Yes
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
<Fig. 2> Eddy current induced by an external
magnetic coil
Controller & Driver
 A driving circuit to feed electric current to
the probes
 A control circuit to generate timing signals
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
Dept. of Medical Engineering
Graduate School of East-West Medical Science
Design of Magnetic Acupuncture Probes
6kV
Transfer
Capacitor
Voltage
250ms
Time
2kV
Discharge
Capacitor
Voltage
200ms
20ms ~ 1s
Time
(1Hz ~ 50Hz)
2kA
Acupuncture
Coil Current
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.
In fig. 9, the magnetic flux densities along
the x-axis at several z-values are shown.
0.7
B [T] 0.6
z = -2mm
0.5
0.4
z = -5mm
0.3
0.2
0.1
z
z
Time
0
y
Magnetic core
(m=20000m0)
<Fig. 5> Timing diagrams to control the
driving circuit
Coil
2.5mm
32.5mm
5mm
z = -10mm
0
1
2
3
4
5
6
7
8
9
10
x [cm]
x
<Fig. 9> The magnetic flux densities
along the x-axis
80mm
Maximum pulsing frequency
x
10mm
 50 Hz
Maximum voltage of the discharge capacitor
 2 kV
Capacitance of the discharge capacitor
<Fig.7> A schematic diagram of the
magnetic acupuncture probe
 100 mF
Inductance of the magnetic coils
 30 ~ 40 mH
Number of pulsing channels
 4 channels
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]
Conclusions
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.
References
<Fig. 6> A photograph of the developed system
<Fig. 8.> Magnetic flux density produced
by the magnetic acupuncture probe
[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