The Experts below are selected from a list of 22455 Experts worldwide ranked by ideXlab platform
Butrus T. Khuri-yakub - One of the best experts on this subject based on the ideXlab platform.
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Capacitive Micromachined Ultrasonic Transducers for Therapeutic Ultrasound Applications
IEEE Transactions on Biomedical Engineering, 2010Co-Authors: S.h. Wong, Mario Kupnik, Ronald D. Watkins, Kim Butts-pauly, Butrus T. Khuri-yakubAbstract:Therapeutic Ultrasound guided by MRI is a noninvasive treatment that potentially reduces mortality, lowers medical costs, and widens accessibility of treatments for patients. Recent developments in the design and fabrication of capacitive micromachined ultrasonic transducers (CMUTs) have made them competitive with piezoelectric transducers for use in Therapeutic Ultrasound applications. In this paper, we present the first designs and prototypes of an eight-element, concentric-ring, CMUT array to treat upper abdominal cancers. This array was simulated and designed to focus 30-50 mm into tissue, and ablate a 2- to 3-cm-diameter tumor within 1 h. Assuming a surface acoustic output pressure of 1 MPa peak-to-peak (8.5 W/cm2) at 2.5 MHz, we simulated an array that produced a focal intensity of 680 W/cm2 when focusing to 35 mm. CMUT cells were then designed to meet these frequency and surface acoustic intensity specifications. These cell designs were fabricated as 2.5 mm x 2.5 mm test transducers and used to verify our models. The test transducers were shown to operate at 2.5 MHz with an output pressure of 1.4 MPa peak-to-peak (16.3 W/cm2). With this CMUT cell design, we fabricated a full eight-element array. Due to yield issues, we only developed electronics to focus the four center elements of the array. The beam profile of the measured array deviated from the simulated one because of the crosstalk effects; the beamwidth matched within 10% and sidelobes increased by two times, which caused the measured gain to be 16.6 compared to 27.4.
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Capacitive micromachined ultrasonic transducer (CMUT) for MR-guided noninvasive Therapeutic Ultrasound applications
TRANSDUCERS 2009 - 2009 International Solid-State Sensors Actuators and Microsystems Conference, 2009Co-Authors: S.h. Wong, Mario Kupnik, Kim Butts Pauly, Butrus T. Khuri-yakubAbstract:In the last decade, noninvasive Therapeutic Ultrasound guided by magnetic resonance imaging (MRI) has increased in popularity for diseases such as cancer and heart arrhythmias. While piezoelectric transducers are the dominant technology for Therapeutic Ultrasound applications, recently capacitive micromachined ultrasonic transducers (CMUTs) have demonstrated competitive performance and ease of fabrication. In this paper, we present a CMUT design for MR-guided Therapeutic Ultrasound, with circular cells and center mass (piston) that fulfills the requirements for therapy of upper abdominal cancers, i.e. 1 MPa peak to peak output pressure at 2.5 MHz. In particular, we discuss the choice of cell shape and membrane topography and their influences on output pressure of the device.
S.h. Wong - One of the best experts on this subject based on the ideXlab platform.
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Capacitive Micromachined Ultrasonic Transducers for Therapeutic Ultrasound Applications
IEEE Transactions on Biomedical Engineering, 2010Co-Authors: S.h. Wong, Mario Kupnik, Ronald D. Watkins, Kim Butts-pauly, Butrus T. Khuri-yakubAbstract:Therapeutic Ultrasound guided by MRI is a noninvasive treatment that potentially reduces mortality, lowers medical costs, and widens accessibility of treatments for patients. Recent developments in the design and fabrication of capacitive micromachined ultrasonic transducers (CMUTs) have made them competitive with piezoelectric transducers for use in Therapeutic Ultrasound applications. In this paper, we present the first designs and prototypes of an eight-element, concentric-ring, CMUT array to treat upper abdominal cancers. This array was simulated and designed to focus 30-50 mm into tissue, and ablate a 2- to 3-cm-diameter tumor within 1 h. Assuming a surface acoustic output pressure of 1 MPa peak-to-peak (8.5 W/cm2) at 2.5 MHz, we simulated an array that produced a focal intensity of 680 W/cm2 when focusing to 35 mm. CMUT cells were then designed to meet these frequency and surface acoustic intensity specifications. These cell designs were fabricated as 2.5 mm x 2.5 mm test transducers and used to verify our models. The test transducers were shown to operate at 2.5 MHz with an output pressure of 1.4 MPa peak-to-peak (16.3 W/cm2). With this CMUT cell design, we fabricated a full eight-element array. Due to yield issues, we only developed electronics to focus the four center elements of the array. The beam profile of the measured array deviated from the simulated one because of the crosstalk effects; the beamwidth matched within 10% and sidelobes increased by two times, which caused the measured gain to be 16.6 compared to 27.4.
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Capacitive micromachined ultrasonic transducer (CMUT) for MR-guided noninvasive Therapeutic Ultrasound applications
TRANSDUCERS 2009 - 2009 International Solid-State Sensors Actuators and Microsystems Conference, 2009Co-Authors: S.h. Wong, Mario Kupnik, Kim Butts Pauly, Butrus T. Khuri-yakubAbstract:In the last decade, noninvasive Therapeutic Ultrasound guided by magnetic resonance imaging (MRI) has increased in popularity for diseases such as cancer and heart arrhythmias. While piezoelectric transducers are the dominant technology for Therapeutic Ultrasound applications, recently capacitive micromachined ultrasonic transducers (CMUTs) have demonstrated competitive performance and ease of fabrication. In this paper, we present a CMUT design for MR-guided Therapeutic Ultrasound, with circular cells and center mass (piston) that fulfills the requirements for therapy of upper abdominal cancers, i.e. 1 MPa peak to peak output pressure at 2.5 MHz. In particular, we discuss the choice of cell shape and membrane topography and their influences on output pressure of the device.
M.s.j. Hashmi - One of the best experts on this subject based on the ideXlab platform.
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Performance characteristics of a Therapeutic Ultrasound wire waveguide apparatus
International Journal of Mechanical Sciences, 2007Co-Authors: Graham P. Gavin, Garrett B. Mcguinness, Finbar Dolan, M.s.j. HashmiAbstract:Abstract Therapeutic Ultrasound angioplasty has been investigated, clinically, by a number of researchers and represents a potentially promising therapy for the treatment of atherosclerotic lesions. To date, there has been no detailed analysis of the effect of mechanical design parameters, such as wire geometry or damping characteristics, on wire waveguide performance. An apparatus capable of delivering Therapeutic Ultrasound down small diameter nickel–titanium (NiTi) wire waveguides is described. The output peak-to-peak (p–p) displacements at the distal tip of a 1.0 mm diameter waveguide were measured experimentally, by means of an optical microscope and image analysis software. The output was measured for a range of waveguide lengths from 118 to 303 mm. Wire waveguide distal tip displacements as high as 98 μm (p–p) at 23.5 kHz were measured. For the range of lengths tested, the experimental measurements show the critical relationship between the length of the waveguide and the output distal tip displacements. A finite element model that can predict the resonant frequencies and distal tip displacements of various wire waveguide geometries and configurations, including the effect of damping, is presented. This numerical model has been validated against the experimental displacement data obtained. This will be a valuable design tool for ensuring the safety and effectiveness of Therapeutic Ultrasound angioplasty procedures.
Quan Wei - One of the best experts on this subject based on the ideXlab platform.
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Effect of Therapeutic Ultrasound for neck pain: A systematic review and meta-analysis.
Archives of physical medicine and rehabilitation, 2021Co-Authors: Wanyi Qing, Xian Shi, Qing Zhang, Lihong Peng, Quan WeiAbstract:Abstract Objective The study evaluated the effects and safety of Therapeutic Ultrasound in patients with neck pain. Data sources The PubMed, EMBASE, CENTRAL and Physiotherapy Evidence databases were searched for articles published prior to 1 December 2020. Study selection Randomized controlled trials that compared the effects of Therapeutic Ultrasound on neck pain were included in this review. The included studies compared Therapeutic Ultrasound plus other treatments with the other treatments or compared Therapeutic Ultrasound with sham or no treatment. Outcome measures involved the effects on pain, disability, and quality of life. Other treatments included all nonultrasonic therapies, e.g., various exercises, massage, and electrotherapy. Data extraction Data on the study population, Therapeutic Ultrasound intervention, combined intervention, outcome measures, and follow-up were extracted. Data synthesis Twelve randomized controlled trials (705 patients) fulfilled the inclusion criteria. Seven studies compared Therapeutic Ultrasound plus other treatments with the other treatments (449 patients). Therapeutic Ultrasound yielded additional benefits for pain, but there was high heterogeneity, and we could not draw a clear conclusion. Ultrasound did not have a better effect on disability or quality of life when it was combined with other treatments. Five studies compared Therapeutic Ultrasound with sham or no treatment (256 patients), and the pooled data showed that Therapeutic Ultrasound significantly reduced pain intensity. No adverse events of Therapeutic Ultrasound were reported in the included studies. Conclusions Therapeutic Ultrasound may reduce the intensity of pain more than sham or no treatment, and it is a safe treatment. Whether Therapeutic Ultrasound in combination with other conventional treatments produced additional benefits on pain intensity, disability or quality of life is not clear. The randomized trials included had different levels of quality and high heterogeneity. A large trial using a valid methodology is warranted.
Matthew J Page - One of the best experts on this subject based on the ideXlab platform.
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Therapeutic Ultrasound for carpal tunnel syndrome
Cochrane Database of Systematic Reviews, 2013Co-Authors: Matthew J Page, Denise Oconnor, Veronica Jean Pitt, Nicola MassywestroppAbstract:Background Therapeutic Ultrasound may be offered to people experiencing mild to moderate symptoms of carpal tunnel syndrome (CTS). The effectiveness and duration of benefit of this non-surgical intervention remain unclear. Objectives To review the effects of Therapeutic Ultrasound compared with no treatment, placebo or another non-surgical intervention in people with CTS. Search methods On 27 November 2012, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL (2012, Issue 11 in The Cochrane Library), MEDLINE (January 1966 to November 2012), EMBASE (January 1980 to November 2012), CINAHL Plus (January 1937 to November 2012), and AMED (January 1985 to November 2012). Selection criteria Randomised controlled trials (RCTs) comparing any regimen of Therapeutic Ultrasound with no treatment, a placebo or another non-surgical intervention in people with CTS. Data collection and analysis Two review authors independently selected trials for inclusion, extracted data and assessed the risk of bias in the included studies. We calculated risk ratio (RR) and mean difference (MD) with 95% confidence intervals (CIs) for primary and secondary outcomes. We pooled results of clinically homogenous trials in a meta-analysis using a random-effects model, where possible, to provide estimates of the effect. Main results We included 11 studies including 414 participants in the review. Two trials compared Therapeutic Ultrasound with placebo, two compared one Ultrasound regimen with another, two compared Ultrasound with another non-surgical intervention, and six compared Ultrasound as part of a multi-component intervention with another non-surgical intervention (for example, exercises and splint). The risk of bias was low in some studies and unclear or high in other studies, with only two reporting that the allocation sequence was concealed and six reporting that participants were blinded. Overall, there is insufficient evidence that one Therapeutic Ultrasound regimen is more efficacious than another. Only two studies reported the primary outcome of interest, short-term overall improvement (any measure in which patients indicate the intensity of their complaints compared with baseline, for example, global rating of improvement, satisfaction with treatment, within three months post-treatment). One low quality trial with 68 participants found that when compared with placebo, Therapeutic Ultrasound may increase the chance of experiencing short-term overall improvement at the end of seven weeks treatment (RR 2.36; 95% CI 1.40 to 3.98), although losses to follow-up and failure to adjust for the correlation between wrists in participants with bilateral CTS in this study suggest that this data should be interpreted with caution. Another low quality trial with 60 participants found that at three months post-treatment Therapeutic Ultrasound plus splint increased the chance of short-term overall improvement (patient satisfaction) when compared with splint alone (RR 3.02; 95% CI 1.36 to 6.72), but decreased the chance of short-term overall improvement when compared with low-level laser therapy plus splint (RR 0.87; 95% CI 0.57 to 1.33), though participants were not blinded to treatment, it was unclear if the random allocation sequence was adequately concealed, and there was a potential unit of analysis error. Differences between groups receiving different frequencies and intensities of Ultrasound, and between Ultrasound as part of a multi-component intervention versus other non-surgical interventions, were generally small and not statistically significant for symptoms, function, and neurophysiologic parameters. No studies reported any adverse effects of Therapeutic Ultrasound, but this outcome was only measured in three studies. More adverse effects data are required before any firm conclusions on the safety of Therapeutic Ultrasound can be made. Authors' conclusions There is only poor quality evidence from very limited data to suggest that Therapeutic Ultrasound may be more effective than placebo for either short- or long-term symptom improvement in people with CTS. There is insufficient evidence to support the greater benefit of one type of Therapeutic Ultrasound regimen over another or to support the use of Therapeutic Ultrasound as a treatment with greater efficacy compared to other non-surgical interventions for CTS, such as splinting, exercises, and oral drugs. More methodologically rigorous studies are needed to determine the effectiveness and safety of Therapeutic Ultrasound for CTS.
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The Cochrane Library - Therapeutic Ultrasound for carpal tunnel syndrome
The Cochrane database of systematic reviews, 2013Co-Authors: Matthew J Page, Veronica Jean Pitt, Denise O'connor, Nicola Massy-westroppAbstract:Background Therapeutic Ultrasound may be offered to people experiencing mild to moderate symptoms of carpal tunnel syndrome (CTS). The effectiveness and duration of benefit of this non-surgical intervention remain unclear. Objectives To review the effects of Therapeutic Ultrasound compared with no treatment, placebo or another non-surgical intervention in people with CTS. Search methods On 27 November 2012, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL (2012, Issue 11 in The Cochrane Library), MEDLINE (January 1966 to November 2012), EMBASE (January 1980 to November 2012), CINAHL Plus (January 1937 to November 2012), and AMED (January 1985 to November 2012). Selection criteria Randomised controlled trials (RCTs) comparing any regimen of Therapeutic Ultrasound with no treatment, a placebo or another non-surgical intervention in people with CTS. Data collection and analysis Two review authors independently selected trials for inclusion, extracted data and assessed the risk of bias in the included studies. We calculated risk ratio (RR) and mean difference (MD) with 95% confidence intervals (CIs) for primary and secondary outcomes. We pooled results of clinically homogenous trials in a meta-analysis using a random-effects model, where possible, to provide estimates of the effect. Main results We included 11 studies including 414 participants in the review. Two trials compared Therapeutic Ultrasound with placebo, two compared one Ultrasound regimen with another, two compared Ultrasound with another non-surgical intervention, and six compared Ultrasound as part of a multi-component intervention with another non-surgical intervention (for example, exercises and splint). The risk of bias was low in some studies and unclear or high in other studies, with only two reporting that the allocation sequence was concealed and six reporting that participants were blinded. Overall, there is insufficient evidence that one Therapeutic Ultrasound regimen is more efficacious than another. Only two studies reported the primary outcome of interest, short-term overall improvement (any measure in which patients indicate the intensity of their complaints compared with baseline, for example, global rating of improvement, satisfaction with treatment, within three months post-treatment). One low quality trial with 68 participants found that when compared with placebo, Therapeutic Ultrasound may increase the chance of experiencing short-term overall improvement at the end of seven weeks treatment (RR 2.36; 95% CI 1.40 to 3.98), although losses to follow-up and failure to adjust for the correlation between wrists in participants with bilateral CTS in this study suggest that this data should be interpreted with caution. Another low quality trial with 60 participants found that at three months post-treatment Therapeutic Ultrasound plus splint increased the chance of short-term overall improvement (patient satisfaction) when compared with splint alone (RR 3.02; 95% CI 1.36 to 6.72), but decreased the chance of short-term overall improvement when compared with low-level laser therapy plus splint (RR 0.87; 95% CI 0.57 to 1.33), though participants were not blinded to treatment, it was unclear if the random allocation sequence was adequately concealed, and there was a potential unit of analysis error. Differences between groups receiving different frequencies and intensities of Ultrasound, and between Ultrasound as part of a multi-component intervention versus other non-surgical interventions, were generally small and not statistically significant for symptoms, function, and neurophysiologic parameters. No studies reported any adverse effects of Therapeutic Ultrasound, but this outcome was only measured in three studies. More adverse effects data are required before any firm conclusions on the safety of Therapeutic Ultrasound can be made. Authors' conclusions There is only poor quality evidence from very limited data to suggest that Therapeutic Ultrasound may be more effective than placebo for either short- or long-term symptom improvement in people with CTS. There is insufficient evidence to support the greater benefit of one type of Therapeutic Ultrasound regimen over another or to support the use of Therapeutic Ultrasound as a treatment with greater efficacy compared to other non-surgical interventions for CTS, such as splinting, exercises, and oral drugs. More methodologically rigorous studies are needed to determine the effectiveness and safety of Therapeutic Ultrasound for CTS.