Healson Technology Co.,Ltd.
17
the Digital Handheld Probe-type Ultrasound System.
b
The field strength should be less than V / m over the whole frequency range of KHz to MHz.
Table 4
Recommended separation distance between portable and mobile radio-frequency communication equipment
and Digital Handheld Probe-type Ultrasound System
Digital Handheld Probe-type Ultrasound System intend to be used in a controlled electromagnetic environment
for RF radiation disturbance. Based on the maximum output power of the communication device, the
purchasers or users of theDigital Handheld Probe-type Ultrasound System can maintain the minimum distance
between the portable and mobile RF communication devices (transmitters) and the Digital Handheld
Probe-type Ultrasound System to prevent electromagnetic interference
Transmitter maximum rated
output power
W
Isolation distance corresponding to different frequency of transmitter /m
KHz
～
MHz
d=.
MHz
～
MHz
d=.
MHz
～
. GHz
d=.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
For transmitters maximum ratings not listed above, the recommended separation distance in meters (m) as a
unit, can be determined by the corresponding transmitter frequency bar formula, where P is the maximum rated
output power of the transmitter provided by the transmitter Healson, in Watt (W) as aunit.
Note: In the MHz and MHz frequency, the higher frequency band should be used.
Note: These guides may not be appropriate for all situations. Electromagnetic propagation is affected by the
absorption and reflection of buildings, objects, and the human body.
Table 5
S/N
Description
Cable Length (m)
Whether to shield
USB cable
.
Yes
1.9 ALARA principle
Using ultrasound should follow ALARA principle(As Low As Reasonably Achievable). On the
premise of obtaining diagnostic information, use the lowest level energy that does not lead to
biological effects as far as possible. Ultrasonic energy depends on the intensity of output and
exposure time. Besides, different patients and clinical cases require different intensity of
ultrasound. Not all inspections can be done by using ultra-low ultrasound energy.The ultra-low
energy ultrasound can only produce low quality images or weak doppler signals, thereby affecting
the reliability of the diagnosis.However,using the sound power which is greater than actual need
does not help to improve the diagnostic information quality, but will increase the risk of biological
