Warning:
The use of ACCESSORIES, transducers and cables other than those specified, with the exception of transducers and cables sold by the manufacturer of the EQUIPMENT or SYSTEM as replacement parts for internal components, may result in increased EMISSION or decreased
Ultrasound safety considerations and data
Ultrasound safety considerations and data
General
Diagnostic ultrasound has been in use for over 25 years with no confirmed adverse effects on patients or instrument operators at the intensities typical of present diagnostic instruments. Although the total absence of adverse effects to human subjects after such extensive use at diagnostic power levels is gratifying,
available data are not conclusive and the possibility that biological effects may be identifiedin the future remains.
It is therefore deemed desirable by medical and other scientific authorities in this field that exposure to ultrasound should be limited to the duration and intensity appropriate for the clinical objective. Because fetal tissue could be more sensitive to biological effects by reason of pregnant subjects be kept toa minimum.
At present, there is a clear consensus that the benefits to patients of prudent use of diagnostic ultrasound outweigh the risks, if any, that may be present.
AngelSounds JPD-100S is a portable battery operated detector designed for the detection of fetal life and confirmation of continued life during pregnancy.
Minimizing patient exposure
Acoustic output of the AngelSounds JPD-100S is internally controlled and cannot changed by the operator in the course of the examination. The duration of sure is, however, fully under the control of the operator. Mastery of the techniques described in the operating instructions will facilitate limit the maximum amount of diagnostic information with the minimum of exposure.
Acoustic output data
The acoustic output of the AngelSounds JPD-100S transducer has been measured in water using a calibrated hydrophone at Authorized Laboratory.
超音波の使用を最低限に抑えるために
AngelSounds JPD-100Sで発信される音波は内部でコントロールされており、検査の途中で変更することはできません。ただし検査にかける時間は使用者が決めることができます。使用説明書に記載されている技術に慣れれば、超音波にさらされる時間を最低限に抑えながら、検査器としての性能を最大限に生かすことが容易になります。
音波データ
AngelSounds JPD-100Sから発信される音波は、権威ある研究所で、水中聴音器を使って水中で測定されています。
Normalized values, which estimate the maximum 'in-situ' dosage to tissue at the point of highest intensity in the beam path have been calculated.
These data are presentedin the following tables.
Table 1 Maximum acoustic output measured in water
Parameter of AngelSounds JPD-100S transducer
Operating mode Continuous Doppler
Frequency 3.3 MHz
Intended use Fetal heart detection
Intended for fetal use Yes
Control settings None
Acoustic intensity:
ISPTA (mW/cm ) <10mW/cm
Peak negative pressure <1 Mpa
Output beam intensity <20 mW/cm
ISPTA=Spatial peak, Temporal Average
Table 2 Estimation of maximum normalized 'in-situ'
Intensity in tissue estimate the 'in-situ' value in tissue at the point of examination, where:
IT=Spatial peak intensity 'in-situ' (tissue)
IW=Spatial peak intensity in water
F=Ultrasound frequency(MHz)
Z=Distance from the face of the transducer
to the point ofmeasurement (cm)
then:
IT=IW exp.(-0.069f.z.)
For example; at a typical point of measurement using the AngelSounds JPD-100S the following value of maximum intensity is obtained: Parameter of AngelSounds JPD-100S transducer
Typical measurement 4.8
Depth in tissue(cm)
Maximum intensity ISPTA 0.8
in tissue(mW/cm )
This also conforms tothe requirements of IEC1157 (details on request).
「超音波の安全性について」は原文にあわせて省略しています。また直後のＧｅｎｅｒａｌは「総評」のような感じだと思うのですが、日本語の文で見かけない表現なので省略しました。