[Study on the dosimetry of ultrasonics applied to medicine; physical concepts of ultrasonics: nature, propagation & the ultrasonic field; experimental research].
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Humans↗
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[Experimental study on the effect of ultrasonic surgical aspiration on blood flow and nerve function by use of ultrasonic Doppler flowmeter and auditory brainstem evoked response].
The effect of intracranial use of an ultrasonic surgical aspirator on major cerebral vessels and nervous tissue was studied in anesthetised adult cats. Experiments were performed without suction in order to investigate only the effect of ultrasonic emulsification. The flow rate of irrigation saline over the tip of the ultrasonic aspirator was set at either slow (4 ml/min) or fast (24 ml/min). Flow in the common carotid artery and superior sagittal sinus was studied by ultrasonic Doppler flowmetry during direct or indirect (intermediated by muscle fragment) application to the vessels of ultrasonic vibration for periods of 5 min. each in increments of 20% from 20% of maximal intensity. Flow in both the carotid artery and the superior sagittal sinus changed only with direct application on vascular surface of ultrasonic vibration of at least 80% of maximal intensity; otherwise flow in these vessels was not changed. The temperature rise caused by ultrasonic vibration was studied by use of a thermister buried in the brain parenchyma of animals 2 mm from the ultrasonic vibratory probe tip. A rise above the physiological range could be prevented by sufficient irrigation. The effect of ultrasonic vibration on the brainstem was studied by using auditory brainstem evoked response (ABR) to monitor brainstem function. An ultrasonic vibratory probe was applied to the ventral surface of the brainstem exposed by transclival approach. ABR changed noticeably only when ultrasonic vibration of 60% or more of maximal intensity was applied directly; otherwise ABR was not changed. The effect of ultrasonic vibration on the intracranial acoustic nerve was also studied by ABR.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
The application of ultrasonic locating techniques to ophthalmology. II. Ultrasonic slit lamp in the ultrasonic visualization of soft tissues.
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Diagnostic Techniques, Ophthalmological↗
[Canal obturation by means of ultrasonic systems. A new concept: combined ultrasonics thermomechanical and ultrasonic sound vibration technics of obturation].
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Gutta-Percha↗
Relationships of ultrasonic backscatter with ultrasonic attenuation, sound speed and bone mineral density in human calcaneus.
Ultrasonic attenuation and sound speed have been investigated in trabecular bone by numerous authors. Ultrasonic backscatter has received much less attention. To investigate relationships among these three ultrasonic parameters and bone mineral density (BMD), 30 defatted human calcanei were investigated in vitro. Normalized broadband ultrasonic attenuation (nBUA), sound speed (SOS), and logarithm of ultrasonic backscatter coefficient (LBC) were measured. Bone mineral density was assessed using single-beam dual energy x-ray absorptiometry (DEXA). The correlation coefficients of least squares linear regressions of the three individual ultrasound (US) parameters with BMD were 0.84 (nBUA), 0.84 (SOS) and 0.79 (LBC). The 95% confidence intervals for the correlation coefficients were 0. 69-0.92 (nBUA), 0.68-0.92 (SOS) and 0.60-0.90 (LBC). The correlations among pairs of US variables ranged from 0.63-0.79. Variations in nBUA accounted for r(2) = 62% of the variations in LBC. Variations in SOS accounted for r(2) = 40% of the variations in LBC. These results suggest that ultrasonic backscattering properties may contain substantial information not already contained in nBUA and SOS. A multiple regression model including all three US variables was somewhat more predictive of BMD than a model including only nBUA and SOS.
Absorptiometry, Photon↗
[Ultrasonic application and its usefulness in ultrasonographic diagnosis, ultrasonically guided needle biopsy and ultrasonic angiography of chest diseases (except breast and heart diseases) (author's transl)].
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Adenocarcinoma↗
The effect of friction reduction in presence of ultrasonic vibrations and its relevance to travelling wave ultrasonic motors.
In many ultrasonic applications frictional effects play an important role (e.g. ultrasonic machining, ultrasonic motors). For optimising the applications in terms of quality, efficiency and lifetime it is important to understand the frictional coupling of the vibrating and the non-vibrating part. This contribution is devoted to give an explanation for the reduction of friction forces which is often observed when ultrasonic vibrations are superimposed to macroscopic motions. Usually adopted coefficients of friction are used for modelling such conditions suggesting special frictional mechanisms for high frequency oscillations, whereas the present paper shows that Coulomb's friction law provides a very good description of the observed phenomena if the kinematics of the system is taken into account. Two systems are investigated. In the first system the ultrasonic and macroscopic movements are parallel and in the second they are perpendicular to each other but also within the plane of contact. Both systems were investigated analytically and experimentally using a specially designed test rig. The measurements confirmed the analytically derived equations and therefore the validity of Coulomb's friction law even for ultrasonic conditions.
Journal Article↗
[A comparative study on external ultrasonic, internal ultrasonic and simple negative pressure liposuction operations under tumescent anesthesia].
OBJECTIVE: To compare the effects of the external ultrasonic, the internal ultrasonic and simple negative pressure liposuction operations under tumescent anesthesia. METHODS: The fat volume, operative time, complications and other indexes of liposuction in 276 cases were collected and compared. RESULTS: External ultrasonic liposuction rapidly emulsified the fat with the least complication. The effects of the internal ultrasonic liposuction was next to the external ultrasonic method while the simple negative pressure liposuction had the poorest effects. CONCLUSION: The external ultrasonic liposuction operation is a safe and effective method for local overweight reduction.
Adolescent↗
Safety of ultrasonic-assisted liposuction (UAL) using a non-water-cooled ultrasonic cannula. A report of six cases of disproportionate fat deposits treated with UAL.
BACKGROUND: There has been much medical investigation and much public relations in the media regarding ultrasonic liposuction. With different methodologies and instrumentation for applying ultrasonic energy to soft tissue in conjunction with liposuction, there is appropriate confusion and skepticism in the medical community. OBJECTIVE: To present case reports that delineate the possible morbidities and/or safety of one method of application of ultrasonic energy to enhance liposuction--ultrasonic assisted Liposuction (UAL) performed with a non-water-cooled ultrasonic cannula. METHODS: Description of six cases in which this procedure was performed and their follow-up over a 4-week period. RESULTS: Much of the morbidity described in these six cases was indistinguishable from that noted following standard tumescent liposuction with micro cannulas. There is a significant risk of heat necrosis of soft tissue with this procedure, which can be minimized with proper technique. CONCLUSIONS: UAL with a non-water-cooled cannula can be performed safely when proper education regarding its usage is followed. However, surgeons wishing to perform this technique must be willing to experience a significant learning curve.
Adipose Tissue↗
Ultrasonic masker clarifies ultrasonic perception in man.
Bone conduction enables ultrasound to be heard. Although several hypotheses about ultrasonic perception have been presented, the perception mechanism of bone-conducted ultrasound has not yet been established. In this study, to investigate ultrasonic perception, the amount of masking produced by 27-, 30- and 33-kHz bone-conducted ultrasonic maskers for air-conducted high-frequency sounds was measured in the frequency range of 8-18 kHz at 1-kHz intervals. The results showed that the air-conducted signals in the frequency range of 10-14 kHz were strongly masked by the ultrasonic maskers. When the masker intensity increased from 5 to 10 dB SL, the growth of masking was more than 10 dB in the frequency range of 9-15 kHz, and the masking spread strongly to lower frequencies. Furthermore, the dynamic range for bone-conducted ultrasound was clearly narrower than that for air-conducted high-frequency sounds. These results suggest that perception of bone-conducted ultrasound depends on inner hair cell activity induced by ultrasound, even without modulation being present, and does not depend on enhancement by the outer hair cells in the basal turn of the cochlea.
Adult↗
The effect of ultrasonic waves on the oxidation current of chlorpromazine in the 38 and 96 kHz-ultrasonic vibrating electrode voltammetry.
In the case of 38 and 96 kHz ultrasonic vibrating electrode (USVE) voltammetry of chlorpromazine, the oxidation current increased considerably with ultrasonic power (amplitude). Movement of the first oxidation product, crimson coloured cation radical, and the streaming of liquid in the neighbourhood of the USVE, were visually observed in order to understand the mechanism of the promotive effects of ultrasound on the oxidation reaction. The reaction profile of the oxidation of chlorpromazine in 38 kHz seems to be somewhat different from that in 96 kHz. However, the mechanical agitation of solution in the area nearest the electrode surface, which is essentially the same fundamental mechanism, takes place in both the cases of 38 and 96 kHz. Both micro- and macro-streamings due to the vibration of a small bubble on the electrode surface with a frequency lower than that of the ultrasonic wave were formed in 38 kHz. These streamings seemed to contribute to the agitation and the exchange of the solution near the electrode surface. However, at the same ultrasonic amplitude, the oxidation current at 96 kHz was much greater than that at 38 kHz. Such a promoting effect of ultrasound on the electrode reaction was considered to be due to the increase of the moving speed or to the acceleration of the particle in the solution.
Antipsychotic Agents↗
Ultrasonic waste-water treatment: incidence of ultrasonic frequency on the rate of phenol and carbon tetrachloride degradation.
Organic compounds in aqueous solution submitted to an ultrasonic irradiation behave differently according to their physical and chemical properties. In this work, hydrogen peroxide formation and the degradation rate of phenol and carbon tetrachloride have been studied at different frequencies: 20, 200, 500 and 800 kHz. Whatever the frequency, it is easier to decompose CCl4 than phenol by means of ultrasonic wave. It is shown that the rates of reactions involving hydroxyl radicals (hydrogen peroxide formation and phenol degradation) have a maximum value at 200 kHz. The best yield observed at 200 kHz for the phenol degradation may be the result of better HO radicals availability outside of the bubble of cavitation. The degradation rate for carbon tetrachloride which decomposes into the bubble of cavitation increases with frequency. Calculating the reaction rate for one ultrasonic period shows that the efficiency of one ultrasonic cycle decreases as frequency increases.
Carbon Tetrachloride↗
[An experimental study of a new ultrasonic scalpel. Observations on the quality of the ultrasonic effect and the prospects for its clinical use on different parenchyma and tissues].
The ultrasonic scalpel has been used for some time in surgery in tissue with a predominantly cellular component since it can be used selectively on the parenchymatous component while respecting the vasculo-stromal component. On the basis of their earlier experience and using a versatile ultrasonic device currently utilised in plastic surgery, the authors subjected a series of animal organs to ultrasonic action at a frequency of 19800 Hz and with an output of 65 Watt. The aim of the study was to evaluate the widest potential in terms of efficiency and safety for the use of a ultrasonic scalpel on a vast range of animal parenchyma (batches of Sprague-Dawley rats). The authors' comments and histological results highlight the striking efficiency of this form of energy in the dissolution of parenchyma while respecting the organ's vascular and stromal components.
Animals↗
[Sawing and welding with ultrasonics. Experimental investigation to test the applicability of an apparatus for sawing and welding bone tissue with ultrasonics in orthopedics (author's transl)].
An experimental investigation of a procedure for sawing and welding of bone tissue with ultrasonics in the area of orthopedics was reported. The welding of bone with ultrasonic waves, bone meal and a plastic adhesive did not product satisfactory results in terms of stability and tissue reaction. The applicability of the ultrasonic saw is limited by the thickness of the bone on which the osteotomy is to be performed. We saw no advantages over against the oscillating saws which were available to us. In our opinion, an indication for the application of the ultrasonic apparatus could be the removal of inflammatory, tumerous or necrotic bone processes.
Animals↗
Ultrasonic tomography by means of an ultrasonic fiberendoscope.
The diagnositc value of ultrasonic tomography of the upper abdominal organs is sometimes limited by bones and gas. Endoscopic ultrasonography (EUST) combines the advantages of the direct visualization of the upper GI tube and the ultrasonic imaging of adjacent organs. The ultrasonic probe consists of a 5 MHz array that generates a good resolution at the acustical focus, the endoscope is a conventional Olympus gastroscope type GFB3. The ultrasonic transducer is firmly attached to the distal end of the endoscope. Combined examinations are performed in 18 patients with biliary, pancreatic and hepatic disorders or postoperative changes. EUST may be of value not only for gastrointestinal but also for retroperitoneal, cardiac, and mediastinal diseases.
Adult↗
Ultrasonic tissue characterization and histopathology in tumor xenografts following ultrasonically induced hyperthermia.
Cells derived from human skin malignant melanoma were implanted subcutaneously in athymic nude mice. Tumors which developed at the implant site were treated with ultrasonically induced hyperthermia at 49 degrees C for 30 min. Tumors were scanned with a computerized diagnostic ultrasound system before and after treatment. Light (LM) and electron (EM) micrographs of tumors were obtained after scanning. Changes in ultrasonic tissue characterization parameters following treatment were well correlated with histopathologic changes observed in tumors. The results are significant in terms of clinical application of ultrasonically induced hyperthermia for treatment of intraocular tumors and the noninvasive monitoring of tumors by use of diagnostic ultrasound.
Animals↗
[Basic studies on ultrasonic surgery. I. Principles, status and perspectives of ultrasonic surgery].
The ultrasonic power with regard to its medical use for resection, treatment, and joining of soft and hard biologic tissues is investigated after the formation of the ultrasonic diagnostics and therapy. The situation of the ultrasonic surgery as an unconventional method for the ingenious complementation of tested operative techniques is valued after the representation of the mode of operation and the present equipment. The trend of development and prospective problems of the research are deduced from them.
Amputation Stumps↗
[Perspectives of ultrasonic diagnosis for the localization of intrauterine pessaries. Ultrasonic presentation of various types of IUDs].
The authors report on their experiences with ultrasonic localization of several types of IUDs. The investigations were carried out with the ultrasonic equipment-B-scanning -- Vidoson S 635 (Siemens). The characteristics of the echosonic pictures of 6 IUDs (Szontágh-IUD, Lippes-Loop, Gravigard, Alza-T, Copper-T, Antigon were studied. It could be stated that the IUDs can be well identified by ultrasonics. In cases of IUD in situ and early pregnancy the amnion and the IUD can be exactly localized.
Amnion↗