The unit of the rate of ultrasound
is Hertz and that of the intensity
(the density of the output power)
of ultrasound is Watt, while the
action strength is W/cm2, i.e.
one unit of output intensity working
on one square centimeter. We have
to set for different intensities
for different purposes, or else
powerful ultrasound could hurt
very much like a keen knife. However,
the kind of ultrasound is not
so easy for common people to touch
with.
There are two kinds of waveforms
that common ultrasound devices
provide. One is continuous waveform
and the other, pulses. The difference
between the two is that the pulse
waveform, unlike the continuous
one having heat efficacy, produces
more powerful output suddenly
in every circle. It is better
for us to treat certain abnormalities.
Hence, we use it on the field
of therapy rather than the others.
On the other hand, heat helps
beautification so much that we
prefer the continuous waveform.
The rate
of ultrasound
The rate
of ultrasound means the numbers of vibration occurred in
a second. Hertz is the unit of measurement. 1000 wave circles
occurring in one second means 1000Hz, 10000 wave circles,
10000Hz. As to ultrasound, over 20000Hz, it is not to be
heard by human beings. At present, the ultrasound devices
for both medicine and beauty are ranged from 1MHz to 5MHz
or so.
The intensity
of ultrasound
The intensity
of ultrasound is measured as Watt, while the action strength
is W/cm2, i.e. one unit of output intensity working on one
square centimeter. Passed through the safe test, the safe
standard of continuous waveform is 1W/cm2 and pulse waveform,
240mW/cm2. For instance, shattering the stones inside the
body needs 10W/cm2 of ultrasound. Cleaning equipment uses
10 to 100W/cm2. Continuous ultrasound of 0.5~3 W/cm2 affects
the transmission of the peripheral nerves obviously. 5~10
minutes 2~3 W/cm2 causes the axis cylinder of the sciatic
nerve to bulge up and then block the nervous pulses. As
to beautification, the action strength must be much lesser,
for not over-stimulating the tissues. On the face, the output
is 0.5W/cm2, to muscles, 1~2W/cm2. That is why almost all
beauty devices limit the highest output. The higher output
is used on the body or to relieve the sore and pain of the
muscles, the lower output, to the facial beautification.
The output level of action strength is displayed as following:
Low output <0.3W/cm2
Middle output 0.3~1.2W/cm2
High output 1.2~3W/cm2
The wave
property of ultrasound
Now we understand
that ultrasound is used in wide range. Besides, the feature
of the wave itself plays an important role too. When the
waves contact with matters, they would reflex different
types of waveforms back. Therefore, dense waves like the
ones produced by ultrasound would supply more delicate readouts.
We take the advantage to distinguish the baby's sex, detect
shoals of fishes, etc.
These foundations mentioned above bring us three best efficacy
of ultrasound that we will explain later. So far we recognize
that not only the tiny bubbles remove away tiny dirt, the
heat also accelerates the metabolism and blood circulation.
It is applied as a new way to solve healthy troubles in
modern days.
One who experienced ultrasound may feel nothing but a little
warm. Nevertheless, we can not neglect the long-time stimulation,
for it causes the dermis tissue fatigued. Generally speaking,
the maximum time is suggested not over 15 minutes. On the
body, 10-15 minutes is suitable, on face, about 10. As to
the guys over weight, prolonging few minutes would be fine.
The time between two treatments is better over than 5 hours.
The transmission
of ultrasound
Ultrasound
can not transmit in the air. If the treatment head does
not completely contact with the skin, the result would not
meet your expectation. Researches display, the transmission
proportion of ultrasound in the air is 0, about 50% in general
water, 60% in distilled water, near 70% in glue matter,
and above 70% in special gel. Besides, another efficacy
of ultrasound is to promote the skin absorbing outside matters,
no matter nutrition or dirt. Hence, the transmission is
worthy to be noticed. Except cleaning your skin before using
ultrasound device, we also suggested you use special gels
or creams (they must be certified by hygiene organization)
in case side effects.
