Calibration and measurement issues for therapeutic ultrasound

Shaw, Adam; Hodnett, Mark

doi:10.1016/j.ultras.2007.10.010

Cited by 68 publications

(59 citation statements)

References 95 publications

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“…Poliachik et al showed that with intensities lower than 100 mW/cm 2 , in underwater mode the thermal effects are minimized. With respect to beam uniformity, Shaw & Hodnett (2008) argues theoretically that for a head of 5 cm 2 the boundary between the near-distant fields is 100 mm. Therefore, according to the literature and the empirical measurement performed during the calibration of the equipment, the distance of 80 mm is located in the near field, in which the peak of intensities (area of beam uniformity) is prevented and The attenuation of the wave, and the thermal effects are minimized.…”

Section: Discussionmentioning

confidence: 99%

Effects of Underwater Lipus on the Morphohistology of the CF-1 Mice Growth Plate in Late Lactation Stage

Henríquez

Yuing

Pallauta³

et al. 2017

Int. J. Morphol.

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Morphol., 35(4):1351Morphol., 35(4): -1358Morphol., 35(4): , 2017. SUMMARY:Ultrasound is one of the most used tools in physiotherapy, its LIPUS modality allows to treat musculoskeletal injuries, but like the conventional ultrasound it is contraindicated its application in areas close to growth cartilage by a possible closure of this one. In the literature there is no conclusive evidence of this contraindication, so the objective of the present study is to evaluate the effects of doses equivalent to underwater LIPUS on the histomorphometry of the proximal tibial epiphysis growth plate in an animal model. LIPUS was applied in underwater mode in the right pelvic limb to 8 mice in p 15 for 4 days, 2 times a day. On completion of 8 sessions the histology of the stimulated limb growth plate was sacrificed and the histology. When evaluating the histomorphometry of the plaque, a significant increase in the thickness and area of the proliferative zone stimulated with LIPUS (p = 0.048) was observed. In the hypertrophic area were observed no significant differences in thickness or areas, but in the hypertrophic area there were significant changes in the histological organization, observing a significant increase of the entire columns in the stimulated plaque (p = 0.04). LIPUS in underwater modality modifies the histomorphometry of the proximal epiphyseal PC of the tibia of rodents in the late postnatal stage, promoting proliferation and columnar organization in the proliferative and hypertrophic zone, respectively.

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Section: Discussionmentioning

confidence: 99%

Effects of Underwater Lipus on the Morphohistology of the CF-1 Mice Growth Plate in Late Lactation Stage

Henríquez

Yuing

Pallauta³

et al. 2017

Int. J. Morphol.

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“…The reduction of the output power and the differences observed in the study can be interpreted by phenomena such as cavitation and standing waves and by considering the intrinsic factors of the coupling media, such as the thickness of the coupling agent layer, the positioning of the glove membrane, the target size, and beam divergence (Casarotto et al, 2004;Poltawski and Watson, 2007;Shaw and Hodnett, 2008;Wells, 1977).…”

Section: General Commentsmentioning

confidence: 99%

Evaluation of gloves as a water bag coupling agent for therapeutic ultrasound

et al. 2017

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Introduction: Therapeutic ultrasound (TUS) is a widespread modality in physiotherapy, and the water bag technique is a coupling method employed in the presence of anatomical irregularities in the treatment area. The aim of the present study is to evaluate the acoustic attenuation of the water bag and its effectiveness as a TUS coupling agent. Methods:The rated output powers (ROPs) of the TUS equipment were evaluated based on IEC 61689. Then, a radiation force balance was used to measure ROP with and without a water bag (latex and nitrile gloves filled with deionized water) between a TUS transducer and the cone-shaped target of the balance. Each experiment was performed five times for each nominal power (

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“…So, measurement of acoustical fields of HIFU transducers is a problem of high importance. 1,2 Various methods can be employed, such as hydrophones, thermocouples, magnetic resonance imaging (MRI), and ultrasound thermometry, to measure the spatial distributions of pressure or intensity in water. There has been considerable interest in using the infrared (IR) technique to investigate the acoustical fields of HIFU transducers [3][4][5] which seems to have increased in recent years.…”

Section: Introductionmentioning

confidence: 99%

Infrared mapping of ultrasound fields generated by medical transducers: Feasibility of determining absolute intensity levels

Khokhlova

Shmeleva

Гаврилов

et al. 2013

The Journal of the Acoustical Society of America

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Considerable progress has been achieved in the use of infrared (IR) techniques for qualitative mapping of acoustic fields of high intensity focused ultrasound (HIFU) transducers. The authors have previously developed and demonstrated a method based on IR camera measurement of the temperature rise induced in an absorber less than 2 mm thick by ultrasonic bursts of less than 1 s duration. The goal of this paper was to make the method more quantitative and estimate the absolute intensity distributions by determining an overall calibration factor for the absorber and camera system. The implemented approach involved correlating the temperature rise measured in an absorber using an IR camera with the pressure distribution measured in water using a hydrophone. The measurements were conducted for two HIFU transducers and a flat physiotherapy transducer of 1 MHz frequency. Corresponding correction factors between the free field intensity and temperature were obtained and allowed the conversion of temperature images to intensity distributions. The system described here was able to map in good detail focused and unfocused ultrasound fields with sub-millimeter structure and with local time average intensity from below 0.1 W/cm 2 to at least 50 W/cm 2 . Significantly higher intensities could be measured simply by reducing the duty cycle.

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Calibration and measurement issues for therapeutic ultrasound

Cited by 68 publications

References 95 publications

Effects of Underwater Lipus on the Morphohistology of the CF-1 Mice Growth Plate in Late Lactation Stage

Effects of Underwater Lipus on the Morphohistology of the CF-1 Mice Growth Plate in Late Lactation Stage

Evaluation of gloves as a water bag coupling agent for therapeutic ultrasound

Infrared mapping of ultrasound fields generated by medical transducers: Feasibility of determining absolute intensity levels

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