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PubMed1994

[Laser and ultrasonic therapy in the treatment of acute purulent diseases of the soft tissues in children].

The article analyses the results of active treatment of pyoinflammatory diseases in 138 children by means of CO2-laser and ultrasonic cavitation. The control group was formed of 145 children who were treated by the commonly applied methods. The efficacy of surgical debridement was appraised according to the number of bacteria per g of tissues. Various methods of opening and treatment of the purulent cavity are compared. The differentiated use of the laser beam and ultrasonic cavitation depending on the character of the pathological process is substantiated. The schemes of ultrasonic cavitation with the use of various solutions and their combination depending on the phase of the wound process are shown. A combination of laser cleansing and ultrasonic cavitation is most rational. Complete epithelialization of the wound occurs 5-6 days earlier than in the control group.

Bacterial Infections↗

PubMed1993

Revision total hip arthroplasty using ultrasonically driven tools. A clinical evaluation.

A three-center clinical evaluation of the use of ultrasonic instrumentation for cement removal during 90 revision total hip arthroplasties was undertaken. In conjunction with hand tools, cement removal was facilitated with ultrasonic tools. Superficial bone burns were seen in eight cases (9%). Bone perforations were created with ultrasonic tools in three cases (4%)--two followed perforations already created by hand tools in the proximal metaphyseal area. Only one perforation (1%) was made in the shaft of the femur. Ultrasonic instrumentation is a valuable adjunct for cement removal in revision total hip arthroplasty.

Acetabulum↗

PubMed1993

Prosol-chlorhexidine irrigation reduces the incidence of bacteremia during ultrasonic scaling with the Cavi-Med: a pilot investigation.

The purpose of this pilot investigation was to determine whether the incidence of bacteremia following subgingival ultrasonic scaling and root planing could be reduced by the use, pre- and intraoperatively, of an irrigant containing 0.12 per cent chlorhexidine (CHX); Prosol. Individuals having evidence of significant periodontal disease (minimum of seven sites per quadrant 4.0 mm and bleeding on probing) were entered into this study. By use of a random number table, patients were assigned to either the experimental or control groups. The procedures, as described below, were carried out in a double blind fashion so that neither the investigator nor the patient was aware of whether Prosol or placebo was being used. The placebo solution was flavored to make it indistinguishable from Prosol. Patients were first anesthetized. Their gingival crevices were then irrigated using the Cavi-Med ultrasonic scaler. At this point, the ultrasonic action was not activated. Ten minutes later, ultrasonic scaling and root planing with the Cavi-Med unit were begun with a continuous flow of either the placebo or control solutions. Blood samples were taken preoperatively, while postoperative samples were taken one minute after completing the scaling of each quadrant and then 10 minutes after scaling the second quadrant. Routine aerobic and anaerobic bacterial culture methods were used to identify viable blood-borne bacteria. The results show that there was no difference in the distribution or presentation of periodontal disease between the experimental and control quadrants.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Effectiveness of ultrasonic cleaning of dental instruments.

PURPOSE: To quantitate blood contamination present on dental instruments used for routine prophylaxis and to assess the effectiveness of ultrasonic decontamination in reducing blood and virus contamination on dental instruments. MATERIALS AND METHODS: Human blood contamination present on dental instruments obtained after routine prophylaxis was analyzed using IgG as a blood marker. RESULTS: The estimated contaminating blood volume was found to normally range between 1.4 x 10(-6) to 2.0 x 10(-4) ml. Attempts to saturate the instruments with blood contamination suggested that the maximum possible retained blood volume was about 10-fold higher than the normal levels of contamination. Hand scrubbing of contaminated instruments was both relatively ineffective and inconsistent in removing blood contamination. Decontamination in an ultrasonic cleaner was more effective than hand washing, resulting in greater than a 100-fold reduction of blood contamination. Using a mouse model virus (lactate dehydrogenase-elevating virus, LDV), high levels of virus contamination of dental instruments and dental handpieces were achieved, as determined by assay of residual virus. Ultrasonic treatment reduced the level of virus contamination present on dental instruments by one million-fold, and virus contamination present in dental handpieces was reduced by one thousand-fold. These results provide quantitative estimations of the infection threat and its reduction by ultrasonication, posed by human-exposed dental instruments.

Animals↗

PubMed1996

Ultrasonic decalcification of calcified valve and annulus during heart valve replacement.

A heavily calcified heart valve annulus increases the likelihood of sequelae after prosthetic valve replacement. Such sequelae include cerebral embolism, paravalvular leakage, valvular dysfunction, rhythm disturbance, hemolysis, communication of the heart chambers, and rupture of the posterior wall of the left ventricle. From January 1991 through June 1994, we performed heart valve replacement on 30 patients, using an ultrasonic surgical aspirator to remove calcific deposits. We placed aortic valve prostheses in 12 patients, mitral valve prostheses in 13 patients, and both aortic and mitral prostheses in 5 patients, after ultrasonic débridement of calcified annuli. All patients were re-examined 6 months after surgery: echocardiographic study showed no paravalvular leakage or valve-related complications. In our experience, ultrasonic decalcification of the annulus is superior to traditional methods. We advocate the use of ultrasonic débridement as an adjunctive tool in calcified heart valve replacement.

Adult↗

PubMed1995

Preparation of curved canals using a combined hand-filing, ultrasonic technique.

Because of the difficulties involved in endodontic preparation of curved canals, many techniques have been suggested using mechanical means to improve final results. Ultrasonics have been used in dentistry for many years as adjuncts for cleaning instruments and as aids in scaling during periodontal treatment. Recent reports on their use in canal preparation have indicated that cleaner canals were obtained. This has led to attempts at using this instrument in curved canals. In this study, preparation with ultrasonics alone in canals of extracted human teeth with curvatures of 30 degrees or greater led to severe straightening, zipping, and strip perforations. The use of ultrasonics more coronally, with hand filing at the apex, avoids these problems. This article presents a step-by-step technique for a combination of hand filing with ultrasonics preparation.

Humans↗

PubMed1997

Scanning electron microscopic evaluation of the cleanliness of a new ultrasonic root end preparation.

Recently introduced ultrasonic instrumentation techniques for root end preparation have revolutionized the field of endodontic surgery. The specially designed tips offer improved access to the root end and create more conservative root and preparations while decreasing the amount of retained debris. This study compared the cleanliness of root end preparations made using ultrasonic instrumentation with that of those prepared in a traditional manner using a microhandpiece bur. We used 10 extracted maxillary human premolars and molars. After cleaning, shaping, and obturation of the root canals, a 3 mm root end resection perpendicular to the long axis of the root was performed with a carbide fissure bur. The roots were randomly divided into two groups and root end preparations were made using the two aforementioned techniques. The roots were longitudinally split and sputter-coated with gold for scanning electron microscopic study. Three independent dentists used a standardized grading system to evaluate the cleanliness of the root end preparations. The ultrasonic preparation had significantly less superficial debris and a thinner smear layer than the microhandpiece preparation (p < 0.05). There were no significant differences between the canal and isthmus portions of the root end preparations within each group in either superficial debris or smear layer. This indicates that cleaner surfaces for root end cavities are created using ultrasonic retrotips than using microhandpiece burs.

Dental Pulp Cavity↗

PubMed1997

Surface integrity of composite inlays following ultrasonic vibration.

PURPOSE: To assess the effect of ultrasonic vibration on the surface integrity of a resin composite inlay. MATERIALS AND METHODS: Ultrasonic vibration in the form of a scaling tip oriented either parallel or perpendicular to the surface was applied to 2 mm thick, 10 mm wide composite discs and the experiment was repeated with the probe oriented perpendicular using composite or rubber shields. The indentations produced were measured using a form Talysurf profilometer. The surfaces of the discs were also observed using scanning electron microscopy. Five discs were used for each experiment. RESULTS: Both parallel and perpendicular orientations produced an indentation with a scattering of composite debris. A significant increase in the depth of indentation occurred if the vibrations of the ultrasonic scaler were oriented parallel to the composite surface (Two sample t- test, P < 0.01). The presence of a composite shield significantly reduced (Mann-Whitney, P < 0.05) the depth of indentation but produced roughening of the surface with impaction of material from the shield onto the surface. The rubber shield, however, polished the surface significantly smoother than the control specimens (Mann-Whitney, P < 0.05). Microscope slide separation was used to measure the thickness of composite luting agent following vibration with an ultrasonic scaling tip with and without a protective sleeve. There was a significantly thinner film of luting agent when an unsleeved scaler was used (ANOVA, P < 0.001). Although an unguarded tip oriented perpendicular to the surface appears to result in the best energy transfer for a thin layer of composite luting agent, it does, however, create minimal surface damage.

Analysis of Variance↗

PubMed1998

Hearing in mole crickets (Orthoptera: Gryllotalpidae) at sonic and ultrasonic frequencies.

We have studied auditory responses in two species of mole cricket (Scapteriscus borellii and S. abbreviatus) to determine (1) whether they show sensitivity to ultrasound, (2) whether their hearing (at both low and high frequencies) is based on the same neural circuitry as that of true crickets, and (3) whether ultrasound sensitivity in different mole cricket species varies with their ability to fly. S. borellii are sensitive to ultrasonic frequencies. There is evidence of a segregation of frequency bands in prothoracic auditory neurons. There are two pairs of omega neurons (ONs) with similar morphology to ON1 of true crickets. The two pairs of ONs differ in tuning. One pair has two sensitivity peaks: at the frequency of the calling song of this species (3 kHz), and in the ultrasonic range (25 kHz). The other pair lacks the high-frequency sensitivity and responds exclusively to frequencies in the range of the species song. These two types are not morphologically distinguishable. In S. abbreviatus, only one class of ON was found. S. abbreviatus ONs are narrowly tuned to the frequency of the species' calls. A T-neuron had the best ultrasonic frequency sensitivity in S. borellii. This cell showed a broad tuning to ultrasonic frequencies and was inhibited by low-frequency stimuli. A morphologically similar neuron was also recorded in S. abbreviatus, but lacked the high-frequency sensitivity peak of that in S. borellii. We also assessed the responses of flying S. borellii to ultrasound using field playbacks to free-flying animals. The attractiveness of broadcast calling song was diminished by the addition of an ultrasound signal, indicating that S. borellii avoid high-frequency sound. The results indicate that mole crickets process low-frequency auditory stimuli using mechanisms similar to those of true crickets. They show a negative behavioural response to high-frequency stimuli, as do true crickets, but the organization of ultrasound-sensitive auditory circuitry in mole crickets differs from that of true crickets.

Acoustic Stimulation↗

PubMed1998

Laparoscopic cholecystectomy using ultrasonically activated coagulating shears.

Ultrasonic energy has recently been used for surgical cutting and coagulating. A prospective randomized study was undertaken to determine the effectiveness of ultrasonic energy versus monopolar electrosurgery in human laparoscopic cholecystectomy. Two hundred patients were enrolled and randomized into two groups of 100 patients each. Group A patients underwent laparoscopic cholecystectomy with monopolar electrocautery. Group B patients underwent laparoscopic cholecystectomy with ultrasonically activated shears. In 18 cases of this group, the cystic artery was coagulated and cut without clips. Subhepatic closed drainage was left for 24 h in patients who were candidates for oozing of blood or leakage of bile. The median operating time was 45 min in group A and 37 min in group B. Subhepatic drainage was left in 37 patients of group A and 26 of group B. The median blood loss was 14 ml in group A and 2 ml in group B, while 3 patients of group A and none of group B had bile leakage from the bed of the gallbladder for 1, 1, and 6 days, respectively. Postoperative ultrasound examination showed a minor subhepatic fluid collection in 5 patients of group A and in 1 patient of group B. All these collections were treated without drainage. The length of hospital stay was 1.9 +/- 0.5 days in group A and 1.4 +/- 0.2 days in group B. Postoperative pain scores, nausea, and vomiting were equivalent in both groups. It is concluded that ultrasonically activated coagulating shears are safer, easier to use, faster, and less prone to intraoperative complications and postoperative morbidity than monopolar electrocautery in laparoscopic cholecystectomy.

Adult↗

PubMed1986

Further studies on ultrasonic properties of blood clots.

Two-dimensional echocardiography has been found to be an effective clinical tool in diagnosing intracardiac thrombi. Misdiagnosis may, however, still frequently occur because of the difficulty in differentiating the thrombi from other intracavitary masses based only on the echographic appearance of these structures. Ultrasonic tissue characterization techniques have been used in attempts to minimize this diagnostic uncertainty. Previously, we have shown that all ultrasonic parameters of blood, including ultrasonic backscatter, a quantitative measure of echogenicity, at 7.5 MHz increase rapidly following clotting. In this article, we report recent results on the measurements of attenuation and backscatter of thrombi as a function of time following clotting over the frequency range of 3 MHz to 8 MHz. These results indicate that ultrasonic backscatter from thrombi 12 h old is at least 18 dB higher than that of unclotted blood over the frequency range of 3 MHz to 8 MHz, and the slope of the attenuation coefficient is increased to 0.43 dB/cm-MHz. Comparison with the backscatter of bovine myocardium shows that the myocardium is more echogenic than fresh thrombi and is less echogenic than thrombi 12 to 24 h old. Similar results were also obtained for integrated backscatter measurements over the same frequency range.

Animals↗

PubMed2006

Multiple breath washout with a sidestream ultrasonic flow sensor and mass spectrometry: a comparative study.

Over recent years, there has been renewed interest in the multiple breath wash-out (MBW) technique for assessing ventilation inhomogeneity (VI) as a measure of early lung disease in children. While currently considered the gold standard, use of mass spectrometry (MS) to measure MBW is not commercially available, thereby limiting widespread application of this technique. A mainstream ultrasonic flow sensor was marketed for MBW a few years ago, but its use was limited to infants. We have recently undertaken intensive modifications of both hardware and software for the ultrasonic system to extend its use for older children. The aim of the current in vivo study was to compare simultaneous measurements of end-tidal tracer gas concentrations and lung clearance index (LCI) from this modified ultrasonic device with those from a mass spectrometer. Paired measurements of three MBW, using 4% sulfur hexafluoride (SF(6)) as the tracer gas and the two systems in series, were obtained in nine healthy adult volunteers. End-tidal tracer gas concentrations (n = 675 paired values) demonstrated close agreement (95% CI of difference -0.23; -0.17%, r(2) = 1). FRC was slightly higher from the MS (95%CI 0.08;0.17 L), but there was no difference in LCI (95%CI -0.10; 0.3). We conclude, that this ultrasonic prototype system measures end-tidal tracer gas concentration accurately and may therefore be a valid tool for MBW beyond early childhood. This prototype system could be the basis for a commercial device allowing more widespread application of MBW in the near future.

Adult↗

PubMed1993

Ultrasonic velocity measurements through the calcaneus: which velocity should be measured?

The assessment of skeletal integrity by the measurement of ultrasonic velocity through the calcaneus has only recently become widely available and is usually made in conjunction with the measurement of broadband ultrasonic attenuation. Using data obtained with a contact ultrasonic bone analyser (CUBA) system, this report examines whether ultrasonic studies of the heel require the measurement of true velocity of sound in the calcaneus (Vbone), or whether heel velocity (Vheel, defined as the mean velocity through bone and soft tissue) or time of flight velocity (Vtof, defined as the mean velocity between the two transducers) are adequate surrogates. The populations selected for study were 15 healthy young women (group 1, mean age 26 years), 231 healthy peri- and postmenopausal women (group 2, mean age 52 years) and 33 osteoporotic women with confirmed vertebral fracture (group 3, mean age 66 years). Precision was studied by performing 10 repeated scans on the subjects in group 1 and duplicate scans on 144 women randomly selected in groups 2 and 3. Precision was expressed as the percentage coefficient of variation (CV). Both precision studies yielded similar results. The precisions (and 5% to 95% ranges) for all groups combined were: Vbone 2.71% (1465-1809 m/s); Vheel, 1.10% (1511-1646 m/s): Vtof, 0.70% (1349-1425 m/s). Although the precision data suggest Vtof should be preferred, when the range of clinical values is taken into account the smaller CV is exactly cancelled by the narrower range.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1983

Endoluminal ultrasonic scanning in the evaluation of rectal cancer: a preliminary report of 13 cases.

In 13 patients with a verified tumor of the rectum, endoluminal ultrasonic scanning was performed to evaluate the degree of tumor infiltration in the muscular wall and the perirectal tissue. In 11 cases the degree of tumor infiltration found by ultrasonic scanning was in complete accordance with the histopathologic finding. In 2 cases the examination was incomplete because the ultrasonic probe could not pass the tumor. We believe that endoluminal ultrasonic scanning will further development of the equipment will be a valuable additional diagnostic tool in the evaluation of gastrointestinal tract tumors. It will make it possible to decide whether local excision of the tumor is possible, based on the diagnostic procedure.

Carcinoma↗

PubMed1993

Automatic quantification of withdrawal from 5-day diazepam in rats: ultrasonic distress vocalizations and hyperreflexia to acoustic startle stimuli.

The purpose of the present work was to develop an objective and precise method to quantify withdrawal responses from anxiolytics relying on ethologically valid responses. Behavioral effects of diazepam withdrawal in rats are automatically measured that appear to correspond to clinically relevant disturbances in affective and sensory-motor functions. Ultrasonic vocalizations and startle reflexes in response to acoustic stimuli were measured as indices of withdrawal 24 h after 5 days of 2.5, 5 or 10 mg/kg diazepam, b.i.d., IP in male Long-Evans rats. About 60% of male rats emit 22-26 kHz ultrasonic calls when exposed to acoustic startle stimuli (18 presentations, 9 at 105 dB and 9 at 115 dB, each 30 s apart on average). Diazepam-withdrawn rats exhibited startle responses with larger maximal and average amplitude and emitted more frequent 22-26 kHz ultrasonic vocalizations than vehicle-treated control animals. The magnitude of the withdrawal changes in ultrasonic calls and in startle reflex amplitude increased significantly already at the low 2.5 mg/kg diazepam dose in spite of considerable individual variability. The increased ultrasound rates during diazepam withdrawal contrast with the suppressive effects of acutely administered diazepam in drug-naive rats. The current methodology offers the opportunity to more adequately characterize withdrawal from anxiolytic substances in a quantitative, objective and automated manner.

Acoustic Stimulation↗

PubMed2006

Dynamic assessment of the focal hepatic lesion in rats using ultrasonic contrast agent.

The focal hepatic lesion caused by local injection of absolute alcohol in rats was evaluated with ultrasonic contrast agent and pathologic examination. Twenty adult Wistar rats weighing about 200 g were injected with absolute alcohol (0.05-0.1 mL each one) on the exterior left lobe of the liver under the monitoring of ultrasound. Pulse inversion harmonic imaging was used to evaluate the focal lesion after bolus injection of ultrasonic contrast agent (0.05 mL/200 g) through caudal vein. Seven days later, the focal lesion was studied again as before. The exterior left lobe of liver with focal lesion was incised and underwent pathologic examination. The results showed that all of the focal lesions could be defined clearly after bolus injection of the ultrasonic contrast agent under the mode of pulse inversion harmonic imaging. There was good correlation between the size of the focal lesion measured by ultrasound on the 7th day after the "ablation" under the mode of pulse inversion harmonic imaging and that gotten by pathologic examination (P = 0.39). The focus size measured by ultrasound right after the ablation was larger than that gotten by pathologic examination (P = 0.002). It was concluded that ultrasonic contrast agent plus pulse inversion harmonic imaging could be used to assess the size of the focal hepatic lesion caused by local injection of absolute alcohol in rats.

Animals↗

PubMed1976

Combined hemodynamic-ultrasonic method for studying left ventricular wall stress: comparison with angiography.

Calculation of left ventricular wall stress in man has traditionally required angiographic and left ventricular pressure measurement, making study of interventions difficult. We have developed a combined hemodynamic-ultrasonic technique for measuring left ventricular meridional wass stress (sigma m) throughout the cardiac cycle. Simultaneous measurements of left ventricular pressure, ultrasonically determined wall thickness (h[echo]), and minor axis (D[echol]) were made during cardiac catheterization in nine subjects, three with chronic left ventricular pressure overload, four with left ventricular volume overload and two with normal left ventricular function. Within 30 minutes, left ventricular cineangiography was performed in each subject and angiographic wall thickness (h[angio]) and minor axis (D[angio]) were measured. Comparison of values for each subject throughout the cardiac cycle (average 18 data points/cycle) yielded close correlation: For D(echo) versus D(angio), r values ranged from 0.82 to 0.98 whereas for h(echo) versus h(angio), r values ranged from 0.56 to 0.98 for the nine subjects. Meridional wall stress was calculated after the method of Sandler and Dodge as PRi2/h(2Ri + h), where Ri equals the inner wall radius, calculated as D/2 for both ultrasonic and angiographic methods. Agreement between ultrasonic and angiographic methods was excellent in each subject, with close superimposition of the stress-time plots constructed by the different techniques. In summary, a new method for measurement of left ventricular wall stress has been developed and validated by comparison with an angiographic reference standard. This method has potential advantages, including the ability to study meridional wall stress continuously and to assess its response to serial interventions.

Cineangiography↗

PubMed1981

Detection of cardiomyopathic changes induced by doxorubicin based on quantitative analysis of ultrasonic backscatter.

Ultrasonic measurements are valuable in characterizing cardiac dimensions and structure. Recently, analysis of ultrasonic properties of tissue has proved useful in detecting morphologic changes such as those accompanying myocardial infarction. This study was undertaken to determine whether acoustic properties of tissue can be utilized to detect cardiomyopathic changes as well. Cardiomyopathy was induced by prolonged administration of doxorubicin (Adriamycin) (1.2 mg/kg twice weekly) in 25 rabbits and results were compared with those in normal control rabbits, housed identically. The 15 surviving treated animals were killed at selected intervals to 10 to 18 weeks after initiation of drug administration and the hearts were analyzed for collagen content based on hydroxyproline. Regional ultrasonic backscatter was assessed with a frequency-averaging procedure to minimize effects of phase cancellation and with an independent method employing spectral display over the frequency range of 1 to 11 megahertz from which an index of backscatter at a single frequency (2.25 megahertz) could be calculated. In hearts from treated animals, collagen content was significantly increased (p less than 0.05). Integrated ultrasonic backscatter was markedly increased (by more than 500 percent, that is, equivalent to 7 decibels) in fibrotic regions and significantly, although less markedly, in myopathic regions without marked collagen deposition. Thus, increased backscatter correlated with collagen deposition. Backscatter at 2.25 megahertz was significantly increased (by more than 500 percent, that is, equivalent to 7 decibels) in fibrotic regions. These results indicate that alterations in acoustic properties occur in cardiomyopathic tissue and that such alterations can be detected with the use of reflected ultrasound. Accordingly, assessment of integrated backscatter offers a promising approach for early clinical detection and characterization of evolution of cardiomyopathy induced by doxorubicin or of other causes.

Animals↗