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4 Auricular Laser Treatments
4.1
Introduction
4.1.1 Historical Background
Light treatments are about as old as the origins of acupuncture. The first experiments with
sun light were carried out by Hippocrates (460–370 BC) and Galen (131–201 AD). In both
Chinese and Arabic culture there were therapeutic approaches with red light therapy which
was noted and further developed in Europe in the 19
th
century. In the 30s of last century ex-
periments were carried out with fluorescent light emitting a wave length of 632.8 nm. This
frequency is used today by red lasers (
›
4.3.1 Wavelength).
After developing auricular acupuncture Nogier used laser therapy for stimulating auric-
ular points. Using a low, tissue-protective intensity, he experimented with different frequen-
cies (
›
table 4.3-1) and, based on his observation, developed recommendations for clinical
application. Further representatives of Western acupuncture using laser therapy and who
have compiled their experiences include Elias, Voll, and Bahr.
4.1.2 Physical Foundation
Technical Data
■
Energy:
in Joule (1J = 1mWs)
■
Frequency:
frequency of the periodically repeating light pulse; in Hertz (1/s = 1Hz).
■
Coherence:
A fixed phase relationship (spatial and temporal) exists among all parts of
the laser radiation; therefore laser represents light with an extremely high degree of or-
der (coherent light)
■
Power:
in Watt (W) or Milliwatt (mW).
■
Spectrum:
Laser is typically monochromatic (light of only one wavelength) in contrast
to white light which contains all colours.
■
Projection:
Typically, the divergence of the laser light beam is very low (to a large ex-
tent parallel), resulting in a point-like image of the beam on the skin.
■
Wave length
(
›
4.3.1): in nanometres (nm)
Penetration depth
This is the depth at which a third of the original radiation is still detectable (Monte Carlo
definition).
The penetration depth is determined by the following factors:
■
Power
(
›
4.3.2): decisive factor; the penetration depth is directly proportional to the
power
■
Wave length
(
›
4.3.1): the greater the wave length, the greater the penetration depth
■
Frequency
(
›
4.3.3): has only a negligible effect on the penetration depth
■
Angle of incidence
(
›
4.3.3): lowest reflection loss (20–30 %) at an impact angle of 90°
(‘vertical laser’). With increasing impact angle there is increasing reflection and there-
fore a lower penetration depth.
■
Type of tissue:
Different tissues absorb and reflect the beam differently. Penetration
depth (in decreasing order): fat > skin > muscle > bone
