Report of the Director-General of Health / Commonwealth of Australia.

  • Australia. Department of Health
Date:
[1972]
Catalogue details

Licence: Public Domain Mark

Credit: Report of the Director-General of Health / Commonwealth of Australia. Source: Wellcome Collection.

    63/300 (page 61)
    to noise were ascertained whenever use of the armoured vehicles involved frequent or lengthy stops with the engine idling. Shorter periods of continued running at speed gave rise to substantia] threshold shifts. This finding agrees with previous data obtained by these laboratories. Research into the measurement of sound attenuation of ear protectors has led to the development of procedures for calculating attenuation to octave bands of noise from measurements of pure tone attenuation at third octave levels. The new method is much more accurate than the standard methods presently used. Ultrasonics — physiology An evaluation of the long-term effectiveness of the round window ultrasonic treatment of Meniere’s disease in thirty-eight patients over a three-year period has shown that the treatment has relieved attacks of vertigo in twenty-nine patients (75 per cent) and that preoperative hearing has remained unchanged in thirty-one patients (80 per cent). This compares quite favourably with results obtained from use of other methods of treatment for this condition. Further work was done on the investigation of the mechanism of functional changes caused by ultrasonic irradiation of the inner ear by studying its effects on the cochlear microphonics of guinea pigs. Ultrasonics — medical applications Continuous progress has been made with the use of ultrasonic diagnostic cross-sectional visualisation techniques in the examination of the abdomen, eye, breast and heart. A major report was prepared on the application of the technique in obstetrical and gynaecological examination, and a research program was formulated with several hospitals for studying the application of the technique in the diagnosis of abnormalities in the early foetus. A new multi-element scanner at present under development should allow rapid examination of patients while giving optimum resolution throughout the whole examining plane. Several patents have been taken out on various aspects of its design. The original eye echoscope has been replaced by the Mark 2 instrument, which allows more detailed examination of the eye. Significant developments have been made in the clinical application of the breast echoscope and a number of centres in Sydney are now referring patients to the breast clinic at the Royal North Shore Hospital. The computer which has been installed is being used in the development of a number of concepts relating to the use of digital processing techniques for improving the results of current procedures and for measuring other acoustic parameters of tissue. The resultant new methods should lead to a further increase in the diagnostic information available from ultrasonic visualisation. Standards Staff members continued their active participation in work connected with Australian standards. An extensive series of computer calculations was undertaken to predict the distribution of hearing impairment in a hypothetical population of workers subject to various industrial noise exposures. The definition of impairment itself was a variable in the calculations. The results provided the basis for the laboratories’ comments on relevant parts of the Standards Association of Australia Draft Code of Practice for Hearing Conservation.