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Ultrasonic international 1973
Lilrrnsoundrn Med. & &o/., Vol. I, pp. 331-332. Pergamon Press. 1974. Printed in Great Britain
ULTRASONICS At the Ultrasonics
International Meeting held in London papers of interest to our readers
Real-Time Acoustical-to-Optical P. GREGUSS. New York Medical
INTERNATIONAL
College,
Centre Hospitalier Con, France
U.S.A.
Real-time acoustical-to-optical conversion techniques are reviewed. It is shown that most new real-time displays are based on acousto-optic effects which were suggested several decades ago for the visualization of acoustical field intensity distributions, but are only now realizable through improved technology. The advantages and disadvantages of the systems are discussed together with the use of liquid crystals, one of the most promising developments in acoustical-to-optical converters. The paper will be supported by a short film. The Use of Shaped Acoustic Matching Elements Increase the Effective Aperture of the Sokoloff Tube
University,
Evanston,
to
University
Laboratories,
de Besancon,
Besan-
of Edinburgh,
Edinburgh,
Diagnosis
Scotland
A radical alternative to present cross-sectional scanning techniques using a three-dimensional cathode ray tube display fed from a motorized hand-held probe manipulator is described. The still relatively inexpensive but more sophisticated technique replaces the mechanical hardware of conventional scanning techniques. By providing adequate visual clues such as stereoscopy, perspective and adjustable observer view-point, the operator can make full use of his natural, but highly developed perceptual faculties to relate the information in the three-dimensional echo image to the position of the manipulator on the patient’s skin.
Ultrasonic Research in Medicine in Australia: A Review G. KOSS~FF, Acoustic
et Universitaire
Interactive Ultrasonic Scanning for Medical T. G. BROWN and J. R. GREENING-.
U.S.A.
A method of increasing the effective aperture of the Sokoloff tube to 30 degrees during ultrasonic imaging has been developed. In the past the use of the tube has been limited by its effective aperture of the order of two degrees. The new technique uses hemispheres of acoustic matching material placed on the conversion plate at centres spaced at quarter wavelength intervals.
Commonwealth lia
1973 the following
By using an ultrasonic B-scan device in which the probe is automatically and constantly moving in a distilled water enclosure, it is possible to obtain a tomoechoscopic cinematic picture of the heart. The heart is examined through the left intercostal space (horizontal scan) and the chondral part of the ribs (vertical, parasternal scan). The patient, if possible, is kept in an erect position. In the normal heart the myocardium comes in diastole to the anterior wall of the thorax. In pericardial effusion a ‘vacuum’ space remains free between myocardium and the thorax wall. Regular examinations can be made to examine the increase or healing of pericardial effusion.
J. E. JACOBS, D. A. PETERSEN, Northwestern
from 27 to 29 March were presented.
Tomoechoscopic Evaluation of Pericardial Effusion F. WEILL, J. C. BECKER and J. R. KRAEHENBLJHL.
Converters
New York,
1973
Sydney, Austra-
Australian research on ultrasonic techniques in medicine commenced in 1959. In diagnosis the emphasis has been on technological advances in cross sectional visualization techniques and their clinical application in the examination of the abdomen, eye and breast. Clinical research using commercial equipment is also being undertaken in several centres. In surgery, research has been on the ultrasonic treatment of Meniere’s disease and of laryngeal papillomas. Present technological research is based on phased arrays to electronically steer and focus the beam. Digital on-line processing of the ultrasonic data to improve the sensitivity and resolution of the echograms and to measure other acoustical parameters such as absorption and velocity is also under study. 331
lmpediography: A New Ultrasonic Technique for NonDestructive Testing and Medical Diagnosis J. P. JONES, Bolt Beranek
and Newman
Inc, Massachusetts,
U.S.A.
A new technique suitable for medical diagnosis and nondestructive testing is described. Termed impediography, this method employs time-domain deconvolution of appropriately shaped acoustic impulses and their echoes to produce a temporal waveform which can be related to physical parameters such as impedance. The results of an experimental study involving several biological and nonbiological test objects will be presented.
332 7.
Ultrasonics Study of Decompression Sickness sonic Imaging of Bubbles R. S. MACKAY, Boston
University,
Massachusetts,
International
8.
U.S.A.
A New Method to Detect the Movements of Bodies in an Electrolyte or Colloid M. POLLAK, G. QUENTIN and P. WACKHERR, University
different masses and frictional coefficients, with consequent periodic variations of potential. Part of the ultrasound is reflected by the fetal heart in movement and gives Debye’s vibration potentials which can interfere with an external imposed electric field. The study of the fetal cardiac activity can therefore be carried out by completely external means.
(Bends) Using Ultra-
Diverse structures in animal and human legs have been observed by both continuous Doppler and pulsed systems during pressure changes. By using a fast sector scan with combined brightness and deflection display and a synchronized tine camera, it has been possible to observe the pattern of bubbles come and go, particularly in vessels and in the vicinity of fat pads. The equipment and methods feature novel aspects which have allowed decompression by ultrasonic observation alone. A film showing current work will be shown.
of Paris, Paris, France
The evaluation of fetal heart activity is investigated by a new method using ultrasonic waves and an electric field. Theoretical interpretations can be related to ultrasonic Debye’s vibration potentials. By introducing ultrasonic waves into an electrolytic or colloidal solution at a given point, periodic excesses of either cations or anions appear. This is because of differences in the velocities imparted to the cations and anions through their
1973
9.
A Method of Measuring the Worst-Case Total Dose Received by a Patient in Ultrasonic Pulse-Echo Scanning T. A. WHITTINGHAM, Regional Medical Physics Department, Tyne, England
Newcastle-upon-
A technique of displaying a number proportional to the total ultrasonic energy received by a patient is described. The method assumes that acoustic coupling between transducer and patient has been perfect. This worst-case measurement mcludes automatic allowance during the course of a scan for changes of the electrical power delivered to the transducer, and of the pulse repetition frequency. Allowance is also made for the frequent intervals when the transducer is not in contact with the patient. To convert the displayed number to absolute units of energy it would be necessary to measure, for each transducer, the acoustic energy of a single pulse radiating into a matched load. It is shown how this circuit may be combined with that of an electronic caliper, with resulting benefits of space, cost and display simplification.
ULTRASONICS At the Ultrasonics
International Meeting held in London papers of interest to our readers
Real-Time Acoustical-to-Optical P. GREGUSS. New York Medical
INTERNATIONAL
College,
Centre Hospitalier Con, France
U.S.A.
Real-time acoustical-to-optical conversion techniques are reviewed. It is shown that most new real-time displays are based on acousto-optic effects which were suggested several decades ago for the visualization of acoustical field intensity distributions, but are only now realizable through improved technology. The advantages and disadvantages of the systems are discussed together with the use of liquid crystals, one of the most promising developments in acoustical-to-optical converters. The paper will be supported by a short film. The Use of Shaped Acoustic Matching Elements Increase the Effective Aperture of the Sokoloff Tube
University,
Evanston,
to
University
Laboratories,
de Besancon,
Besan-
of Edinburgh,
Edinburgh,
Diagnosis
Scotland
A radical alternative to present cross-sectional scanning techniques using a three-dimensional cathode ray tube display fed from a motorized hand-held probe manipulator is described. The still relatively inexpensive but more sophisticated technique replaces the mechanical hardware of conventional scanning techniques. By providing adequate visual clues such as stereoscopy, perspective and adjustable observer view-point, the operator can make full use of his natural, but highly developed perceptual faculties to relate the information in the three-dimensional echo image to the position of the manipulator on the patient’s skin.
Ultrasonic Research in Medicine in Australia: A Review G. KOSS~FF, Acoustic
et Universitaire
Interactive Ultrasonic Scanning for Medical T. G. BROWN and J. R. GREENING-.
U.S.A.
A method of increasing the effective aperture of the Sokoloff tube to 30 degrees during ultrasonic imaging has been developed. In the past the use of the tube has been limited by its effective aperture of the order of two degrees. The new technique uses hemispheres of acoustic matching material placed on the conversion plate at centres spaced at quarter wavelength intervals.
Commonwealth lia
1973 the following
By using an ultrasonic B-scan device in which the probe is automatically and constantly moving in a distilled water enclosure, it is possible to obtain a tomoechoscopic cinematic picture of the heart. The heart is examined through the left intercostal space (horizontal scan) and the chondral part of the ribs (vertical, parasternal scan). The patient, if possible, is kept in an erect position. In the normal heart the myocardium comes in diastole to the anterior wall of the thorax. In pericardial effusion a ‘vacuum’ space remains free between myocardium and the thorax wall. Regular examinations can be made to examine the increase or healing of pericardial effusion.
J. E. JACOBS, D. A. PETERSEN, Northwestern
from 27 to 29 March were presented.
Tomoechoscopic Evaluation of Pericardial Effusion F. WEILL, J. C. BECKER and J. R. KRAEHENBLJHL.
Converters
New York,
1973
Sydney, Austra-
Australian research on ultrasonic techniques in medicine commenced in 1959. In diagnosis the emphasis has been on technological advances in cross sectional visualization techniques and their clinical application in the examination of the abdomen, eye and breast. Clinical research using commercial equipment is also being undertaken in several centres. In surgery, research has been on the ultrasonic treatment of Meniere’s disease and of laryngeal papillomas. Present technological research is based on phased arrays to electronically steer and focus the beam. Digital on-line processing of the ultrasonic data to improve the sensitivity and resolution of the echograms and to measure other acoustical parameters such as absorption and velocity is also under study. 331
lmpediography: A New Ultrasonic Technique for NonDestructive Testing and Medical Diagnosis J. P. JONES, Bolt Beranek
and Newman
Inc, Massachusetts,
U.S.A.
A new technique suitable for medical diagnosis and nondestructive testing is described. Termed impediography, this method employs time-domain deconvolution of appropriately shaped acoustic impulses and their echoes to produce a temporal waveform which can be related to physical parameters such as impedance. The results of an experimental study involving several biological and nonbiological test objects will be presented.
332 7.
Ultrasonics Study of Decompression Sickness sonic Imaging of Bubbles R. S. MACKAY, Boston
University,
Massachusetts,
International
8.
U.S.A.
A New Method to Detect the Movements of Bodies in an Electrolyte or Colloid M. POLLAK, G. QUENTIN and P. WACKHERR, University
different masses and frictional coefficients, with consequent periodic variations of potential. Part of the ultrasound is reflected by the fetal heart in movement and gives Debye’s vibration potentials which can interfere with an external imposed electric field. The study of the fetal cardiac activity can therefore be carried out by completely external means.
(Bends) Using Ultra-
Diverse structures in animal and human legs have been observed by both continuous Doppler and pulsed systems during pressure changes. By using a fast sector scan with combined brightness and deflection display and a synchronized tine camera, it has been possible to observe the pattern of bubbles come and go, particularly in vessels and in the vicinity of fat pads. The equipment and methods feature novel aspects which have allowed decompression by ultrasonic observation alone. A film showing current work will be shown.
of Paris, Paris, France
The evaluation of fetal heart activity is investigated by a new method using ultrasonic waves and an electric field. Theoretical interpretations can be related to ultrasonic Debye’s vibration potentials. By introducing ultrasonic waves into an electrolytic or colloidal solution at a given point, periodic excesses of either cations or anions appear. This is because of differences in the velocities imparted to the cations and anions through their
1973
9.
A Method of Measuring the Worst-Case Total Dose Received by a Patient in Ultrasonic Pulse-Echo Scanning T. A. WHITTINGHAM, Regional Medical Physics Department, Tyne, England
Newcastle-upon-
A technique of displaying a number proportional to the total ultrasonic energy received by a patient is described. The method assumes that acoustic coupling between transducer and patient has been perfect. This worst-case measurement mcludes automatic allowance during the course of a scan for changes of the electrical power delivered to the transducer, and of the pulse repetition frequency. Allowance is also made for the frequent intervals when the transducer is not in contact with the patient. To convert the displayed number to absolute units of energy it would be necessary to measure, for each transducer, the acoustic energy of a single pulse radiating into a matched load. It is shown how this circuit may be combined with that of an electronic caliper, with resulting benefits of space, cost and display simplification.