Page 12 of 87 DGH 55B-INS-OMENG Rev: 3
5. Ultrasonic Exposure And Intensities
5.1 Tissue Exposure To Ultrasound Energy
The ultrasound energy emitted by the Pachmate 2 is low intensity and will have no adverse
effects on the patient and/or operator. However, the operator is still cautioned to perform
examinations using the principle of ALARA (As Low As Reasonably Achievable). All
examinations should be done so that the patient receives as little ultrasound radiation as possible.
Do not hold the probe against the eye or other tissue with the system activated except when
making a measurement. Do not make unnecessary measurements.
5.2 Ultrasonic Intensities
The Pachmate 2 has only one mode, and ultrasonic intensity settings are not under the control of
the operator. Thus, the values below are the values to be expected for a typical transducer.
Since the DGH 55B Pachmate 2 is not capable of exceeding either a TI of 1.0 or an MI of 1.0 in
any operating mode, the output of the system is reported as shown in the Table below.
The appropriate Thermal Index is the Thermal Index for Soft Tissue, TIS, for the non-scanning
case with a beam aperture of less than 1.0 cm.
Output Summary Table
The acoustic output values given above are based on a presumed attenuation of ultrasound on
tissue, as developed by the U.S. Food and Drug Administration in 1985, and later incorporated
into other international Standards.
The attenuated intensity in the eye at the transducer focus (corresponding to maximum intensity)
may be calculated according to the formula recommended by the FDA:
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