Ultrasonic Shockwave

This paper introduces the simulation and measurement results of the phased-array focused ultrasound field of two-foci pattern.
Ultrasonic Therapy ; methods ; Ultrasonics

Imaging Techniques ; Ultrasonic Shockwave

The Harmonic Scalpel made by Ultracision is a system for endoscopic cutting. The energy source is vibration. The power box is attached to a forceps or blade, and the vibrational frequency of the blade approaches 55,500 cycles/second. This causes a knife-like action of the blade through tissue, with enough heating to create coagulation of small vessels. When this vibration energy is applied to the forceps configuration, coagulation occurs. By rotating the bottom blade of the forceps, the instrument becomes like a pair of scissors, and the tissue can divide. The Harmonic Scalpel allows the operator to cut using a tactile tissue. No smoke is created, only microaromized water droplets which are rapidly absorbed by the peritoneak surface. The instrument is extremely safe in that only tissue which is touched is cut; the energy source cannot travel through air, such as can happen with electrosurgery and laser surgery.
Animal ; Electrocoagulation ; Endoscopy* ; Human ; Laparoscopy ; Ultrasonic Therapy*

Background: In Vietnam, using dental loupe and ultrasonic tip to detect MB2 canal in mesiobuccal roots of maxillary molars is appropriate and necessary. Objective: The purpose of this study is to assess the effectiveness of magnification and dentine removal when locating the second mesiobuccal canal (MB2) in mesiobuccal roots of maxillary molars. Subject and methods: 49 mesiobuccal roots of maxillary molars were collected and studied. Conventional access of the cavity was prepared. After that, the MB1 and 2 canals in mesiobuccal roots were located in three stages. Stage 1: canals were located with no magnification. Stage 2: additional canals in the same teeth were located under magnification with a dental loupe. Stage 3: additional canals in the same teeth were located by removing dentine from the pulp chamber floor within 3mm from the MB1 canal towards the palatal canal in a groove 2 mm deep using ultrasonic tip (P5, Salatec). Result: The frequency of MB2 canal detection for an ultrasonic tip, dental loupes, and no magnification groups was 77.6%, 59.2% and 24.5%, respectively. Conclusion: Based on these results, more emphasis should be placed on the importance of using magnification dental ultrasonic tip to locate the MB2 canal.
MB2 canal ; Dental loupe ; Ultrasonic tip

A small HIFU system was used to investigate the phase-shift droplet vaporization in vivo and its effect on thermal absorption in tissue-mimicking phantoms. The experiments demonstrated that droplets could be vaporized to bubbles in vivo by the small HIFU system and the volume of bubbles could increase by tens of times. With appropriate droplets concentration, lesion volume produced by HIFU could be increased significantly under the same HIFU parameter.
Fluorocarbons ; Image Enhancement ; Ultrasonic Therapy ; methods

This paper provides a method of positioning the ultrasound probe in MR system. Machining 6 slots or cylinder perpendicular to the ultrasound probe surface on the edge of ultrasound probe as markers, 12 central cylinder ends are chosen as positioning points. By calculating these positioning points' coordinates in MR's coordinate system, the coordinate transformation between the ultrasound and MR coordinate system can be computed. Furthermore, by taking advantage of redundant information, calculating errors can be reduced and the precision can be improved.
Magnetic Resonance Imaging ; Ultrasonic Therapy ; methods

OBJECTIVES: This was a cross sectional study conducted in the Paediatric Institute among infants and children with chronic respiratory symptoms with the following objectives: i) to determine the prevalence of gastro-oesophageal reflux in children with persistent respiratory symptoms, ii) to identify the clinical predictors of GOR (Gastro-oesophageal reflux) in children with persistent respiratory symptoms and iii) assess the validity of abdominal ultrasound, barium oesophagogram and chest radiograph in diagnosing GOR in these patients. MATERIALS AND METHODS: Forty-four patients were recruited over a period of six months. All the presenting symptoms were identified. The patients were subjected to chest radiograph, abdominal ultrasound, barium oesophagogram and 24-hour pH oesophageal monitoring. The predictive validity of clinical symptoms, chest radiograph, abdominal ultrasound and barium oesophagogram were assessed. Twenty-four hours oesophageal pH was the gold standard to diagnose GOR. RESULTS: The mean age of patients was 9.1 months (1-58 months). Thirty-one patients (70.5%) were confirmed to have GOR by pH study. Respiratory symptoms alone were not useful to predict GOR. Cough had the highest sensitivity of 51.6%. Stridor, wheeze and choking each had a specificity of 76%. Wheeze, vomiting, choking and stridor were identified to have high specificity (90-100%) in diagnosing GOR when any two symptoms were taken in combination. Collapse/consolidation was the commonest radiological abnormality but had low sensitivity (35.5%) and specificity (53.8%). However hyperinflation on chest radiograph had a specificity of 92.3% with positive predictive value of 80% in diagnosing GOR. Barium oesophagogram has low sensitivity (37.9%) and moderate specificity (75%) in diagnosing GOR in children with respiratory symptoms. Abdominal ultrasound was a valid mode of diagnosing GOR when there were three or more reflux episodes demonstrated during the screening period with a specificity of 90.9%. However the sensitivity was low i.e. 20-25%. The specificity increased to 90-100% when two positive tests were taken in combination (abdominal ultrasound and barium oesophagogram). However the sensitivity remained low (10-20%). Chest radiograph did not improve the predictive value when considered with the above tests. Combination of clinical symptoms were useful as clinical predictors of GOR. In the absence of a pH oesophageal monitoring, a combination of barium oesophagogram and ultrasound may be helpful in diagnosing GOR.
symptoms <1> ; Respiratory ; Ultrasonic ; Clinical ; Child

Low-intensity pulsed ultrasound (LIPUS) is a promising therapy that has been increasingly explored in basic research and clinical applications. LIPUS is an appealing therapeutic option as it is a noninvasive treatment that has many advantages, including no risk of infection or tissue damage and no known adverse reactions. LIPUS has been shown to have many benefits including promotion of tissue healing, angiogenesis, and tissue regeneration; inhibition of inflammation and pain relief; and stimulation of cell proliferation and differentiation. The biophysical mechanisms of LIPUS remain unclear and the studies are ongoing. In recent years, more and more research has focused on the relationship between LIPUS and stem/progenitor cells. A comprehensive search of the PubMed and Embase databases to July 2020 was performed. LIPUS has many effects on stem cells. Studies show that LIPUS can stimulate stem cells in vitro; promote stem cell proliferation, differentiation, and migration; maintain stem cell activity; alleviate the problems of insufficient seed cell source, differentiation, and maturation; and circumvent the low efficiency of stem cell transplantation. The mechanisms involved in the effects of LIPUS are not fully understood, but the effects demonstrated in studies thus far have been favorable. Much additional research is needed before LIPUS can progress from basic science research to large-scale clinical dissemination and application.
Cell Proliferation ; Humans ; Signal Transduction ; Stem Cells/radiation effects* ; Ultrasonic Therapy/methods* ; Ultrasonic Waves

High-intensity focused ultrasound (HIFU) has been used to precisely ablate a targeted area within the body without harming the overlying tissues. In recent years, HIFU, as a noninvasive, effective and feasible modality, has been used for cancer therapy. The development of HIFU transducer is the key technology of HIFU. This paper shows the acoustic lens transducer, spherical auto-focused transducer, pluralistic auto-focused transducer and the electronic phased array transducer in HIFU treatment, and the performance of each of the four HIFU transducers was evaluated.
Equipment Design ; Humans ; Neoplasms ; therapy ; Transducers ; Ultrasonic Therapy ; instrumentation ; methods