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As transcranial ultrasound stimulation (TUS) advances as a precise, non-invasive neuromodulatory method, there is a need for consistent reporting standards to enable comparison and reproducibility across studies. To this end, the International Transcranial Ultrasonic Stimulation Safety and Standards Consortium (ITRUSST) formed a subcommittee of experts across several domains to review and suggest standardised reporting parameters for low intensity TUS, resulting in the guide presented here. The scope of the guide is limited to reporting the ultrasound aspects of a study. The guide and supplementary material provide a simple checklist covering the reporting of: (1) the transducer and drive system, (2) the drive system settings, (3) the free field acoustic parameters, (4) the pulse timing parameters, (5) in situ estimates of exposure parameters in the brain, and (6) intensity parameters. Detailed explanations for each of the parameters, including discussions on assumptions, measurements, and calculations, are also provided.
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Consenso , Humanos , Encéfalo/fisiología , Encéfalo/diagnóstico por imagen , Terapia por Ultrasonido/normas , Terapia por Ultrasonido/métodosRESUMEN
As transcranial ultrasound stimulation (TUS) advances as a precise, non-invasive neuromodulatory method, there is a need for consistent reporting standards to enable comparison and reproducibility across studies. To this end, the International Transcranial Ultrasonic Stimulation Safety and Standards Consortium (ITRUSST) formed a subcommittee of experts across several domains to review and suggest standardised reporting parameters for low intensity TUS, resulting in the guide presented here. The scope of the guide is limited to reporting the ultrasound aspects of a study. The guide and supplementary material provide a simple checklist covering the reporting of: (1) the transducer and drive system, (2) the drive system settings, (3) the free field acoustic parameters, (4) the pulse timing parameters, (5) in situ estimates of exposure parameters in the brain, and (6) intensity parameters. Detailed explanations for each of the parameters, including discussions on assumptions, measurements, and calculations, are also provided.
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Adaptations to resistance training and subsequent performance can be undermined by inadequate interset recovery. Methods typically used to monitor recovery were developed for longitudinal use, making them time-inefficient within singular exercise bouts. If valid, perceptual recovery status (PRS) may be used as an efficient and inexpensive assessment tool to monitor individual recovery. PURPOSE: The aim of this study was to assess the validity of PRS on monitoring recovery during a high-intensity back-squat session. METHODS: Ten healthy men participated in the 2-session study (separated by at least 48 h). Session 1 included anthropometrics, PRS familiarization, and a 1-repetition-maximum back squat. Session 2 included a high-intensity protocol (5 sets of 5 repetitions; 5-min interset recovery; 85% of 1-repetition maximum). PRS was obtained before the first set and during the last 30 seconds of each 5-minute recovery; rating of perceived exertion (RPE) was also collected. A linear position transducer collected mean barbell velocity (MBV). Repeated-measures correlations assessed the common intraindividual relationships of PRS scores to intraset MBV and RPE, respectively. RESULTS: A very large, positive correlation appeared between PRS and MBV (r [95% CI] = .778 [.613 to .878]; P < .0001). A large, negative correlation emerged between PRS and RPE (r [95% CI] = -.549 [-.737 to -.282]; P < .001). CONCLUSIONS: Results indicate that PRS can be a means for practitioners to monitor individualized recovery. PRS tracked well with RPE, strengthening its utility in a practitioner-based setting. Findings provide insight into the practicality of PRS for recovery monitoring. It could be used alongside other measures (eg, MBV and countermovement jump) to individually program and maintain performance.
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Ejercicio Físico , Entrenamiento de Fuerza , Masculino , Humanos , Postura , Entrenamiento de Fuerza/métodosRESUMEN
The primary purpose of this work was to design and implement a compact, battery-powered, fully wearable applicator for delivering therapeutic low-frequency (20-40kHz), low-intensity (100mW/cm2 ISPTP) (LFLI) ultrasound to enable treatment of chronic wounds in home setting. Such a device does not currently exist, and in addition to engineering aspects associated with electromechanical design, its implementation requires a novel approach involving consideration of feedback received not only from healthcare professionals, but also caregivers. One strong motivation for the novel design approach is to enable individuals with chronic wounds to enhance self-care management of wounds in the home setting instead of a hospital or outpatient clinic setting. In the home setting, the device may be exposed to physical maltreatment, requiring precautions with respect to its sturdiness. Although the holistic approach presented have been applied to the design of an applicator for chronic wounds, the design considerations and execution are transferable to any device targeted for home use. The implementation exemplified here examines transformation of an early, relatively fragile design into a robust, time-programmable, safe tool. The modification, which includes comprehensive reconfiguration and redesign of the electronics driving a piezoelectric transducer is presented along with methodology devised with the field feedback obtained from focus groups. This feedback evinced that in addition to electrical engineering, an extensive background in mechanical engineering, material science, biology, and clinical practice is needed to fabricate an end-user friendly, quality-of-life improving, ergonomic device.
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This work describes a unique ultrasound (US) exposure system designed to create very localized ( [Formula: see text]) sound fields at operating frequencies that are currently being used for preclinical US neuromodulation. This system can expose small clusters of neuronal tissue, such as cell cultures or intact brain structures in target animal models, opening up opportunities to examine possible mechanisms of action. We modified a dental descaler and drove it at a resonance frequency of 96 kHz, well above its nominal operating point of 28 kHz. A ceramic microtip from an ultrasonic wire bonder was attached to the end of the applicator, creating a 100- [Formula: see text] point source. The device was calibrated with a polyvinylidene difluoride (PVDF) membrane hydrophone, in a novel, air-backed, configuration. The experimental results were confirmed by simulation using a monopole model. The results show a consistent decaying sound field from the tip, well-suited to neural stimulation. The system was tested on an existing neurological model, Drosophila melanogaster, which has not previously been used for US neuromodulation experiments. The results show brain-directed US stimulation induces or suppresses motor actions, demonstrated through synchronized tracking of fly limb movements. These results provide the basis for ongoing and future studies of US interaction with neuronal tissue, both at the level of single neurons and intact organisms.
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Drosophila melanogaster , Movimiento , Animales , UltrasonografíaRESUMEN
Background: MemorialCare Medical Group (MCMG) designed and implemented an advanced health care practitioner (AHP)-led home-visit primary care program to address the needs of a frail older adult population, who struggled with arriving for in-office care. We sought to perform a preliminary analysis to determine the program's efficacy. Methods: We conducted a retrospective review of patients enrolled in the program through tabulation of total costs of care, inpatient visits (IPVs), emergency department visits (EDVs), and 30-day readmissions (30DRs) 1-year pre-enrollment and postenrollment. Results: For the prior year and postyear windows, per-member per-month total cost of care decreased 21.4% ($5,883.44-$4,622.31), reflecting a gross savings of $2,693,480.32. Mean IPVs (2.42-1.56), EDVs (1.53-0.93), and 30DRs (0.27-0.13) were reduced. Conclusions: Initial analysis of an AHP-led in-home primary care program for frail seniors shows promise for improved outcomes with a clear decrease in the total cost of care.
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Costos de la Atención en Salud , Servicios de Atención de Salud a Domicilio , Humanos , Anciano , Atención a la Salud , Readmisión del Paciente , Atención Primaria de SaludRESUMEN
This article is a review of the techniques for characterizing ultrasound surgical devices, as a guide to those undertaking a program of measurement, and as a basis for further standardization of those methods. The review covers both acoustic and nonacoustic measurements, with an emphasis on proper techniques, devices, and analyses according to the IEC Standard 61847. Low-frequency hydrophone measurements are presented, which are centered on simple acoustic theory. Inertial cavitation measurements are described based on detailed analyses of shock wave propagation. Cutting force tests are also presented as a basis for determining relative performance characteristics and determining mechanisms of action. Example data from each type of test are given. Comparison between acoustic output measurements, in vitro data, and clinical outcomes help establish that inertial cavitation is the predominant mechanism of soft tissue erosion and emulsification. The test results also demonstrate approaches to improving efficiency while minimizing undesired effects. Finally, recommendations are made for updates to the 61847 Standard and for other device labeling that would improve patient safety.
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Equipo Quirúrgico , Ultrasonido , Humanos , Ultrasonido/instrumentaciónRESUMEN
Transcranial ultrasound stimulation (TUS) has been shown to be a safe and effective technique for non-invasive superficial and deep brain stimulation. Safe and efficient translation to humans requires estimating the acoustic attenuation of the human skull. Nevertheless, there are no international guidelines for estimating the impact of the skull bone. A tissue independent, arbitrary derating was developed by the U.S. Food and Drug Administration to take into account tissue absorption (0.3 dB/cm-MHz) for diagnostic ultrasound. However, for the case of transcranial ultrasound imaging, the FDA model does not take into account the insertion loss induced by the skull bone, nor the absorption by brain tissue. Therefore, the estimated absorption is overly conservative which could potentially limit TUS applications if the same guidelines were to be adopted. Here we propose a three-layer model including bone absorption to calculate the maximum pressure transmission through the human skull for frequencies ranging between 100 kHz and 1.5 MHz. The calculated pressure transmission decreases with the frequency and the thickness of the bone, with peaks for each thickness corresponding to a multiple of half the wavelength. The 95th percentile maximum transmission was calculated over the accessible surface of 20 human skulls for 12 typical diameters of the ultrasound beam on the skull surface, and varies between 40% and 78%. To facilitate the safe adjustment of the acoustic pressure for short ultrasound pulses, such as transcranial imaging or transcranial ultrasound stimulation, a table summarizes the maximum pressure transmission for each ultrasound beam diameter and each frequency.
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Encéfalo , Cráneo , Humanos , Cráneo/diagnóstico por imagen , Ultrasonografía , Acústica , CabezaRESUMEN
This article presents basic principles of hydrophone measurements, including mechanisms of action for various hydrophone designs, sensitivity and directivity calibration procedures, practical considerations for performing measurements, signal processing methods to correct for both frequency-dependent sensitivity and spatial averaging across the hydrophone sensitive element, uncertainty in hydrophone measurements, special considerations for high-intensity therapeutic ultrasound, and advice for choosing an appropriate hydrophone for a particular measurement task. Recommendations are made for information to be included in hydrophone measurement reporting.
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Terapia por Ultrasonido , Ultrasonografía/métodos , Calibración , Procesamiento de Señales Asistido por ComputadorRESUMEN
This quasi-experimental study evaluated the impact of a 10-week evidence-based falls prevention program (Bingocize®) on self-reported fear of falling, general health, physical activity, social isolation, and avoidance behavior, in community-dwelling older adults in Virginia. Participants > 60 years of age (n= 481) attended BingocizeR group sessions twice per week for 10 weeks. The program combined conventional bingo with periodic strength, balance, flexibility exercises, and fall prevention education. Pre and post assessments gauged participants' self-perception of fear of falling, general health, physical activity, social isolation, and avoidance behavior. 481 participants attended at least 80% of the sessions. Following the intervention, paired sample t-tests revealed statistically significant improvements (p <.05) in fear of falling, physical activity, social isolation, avoidance behavior, and yet there was no notable change in self-reported general health. The 10-week BingocizeR program appears to improve physical activity, social isolation, avoidance behavior, and fear of falling. Self-reported general health did not significantly change.
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The Bruce and Astrand treadmill protocols are commonly utilized when assessing maximal oxygen consumption (VO2max). However, the steep grade implemented in the protocols often leads to localized muscular fatigue, potentially causing participants prematurely to terminate the test prior to reaching their true VO2max. The purpose of this study was to evaluate a Novel VO2max protocol that may be better suited for young, apparently healthy populations. The Novel protocol starts at a higher speed and lower initial grade to limit lower extremity fatigue. Fifteen participants performed the Bruce, Astrand, and Novel protocols with the following maximal values recorded from each: VO2max, maximal ventilation (VEmax), respiratory exchange ratio (RER), heart rate (HR), rating of perceived exertion (RPE) and time to exhaustion (TTE). The Novel protocol displayed substantial agreement with both criterion protocols. Mean absolute percent error (MAPE) was less than 10% indicating that the Novel protocol is a valid measurement for VO2max values. Bland-Altman analysis revealed that the Novel protocol exhibited a low degree of bias, with tight limits of agreement when compared to the Bruce (bias ±95% LOA = 0.824 ± 3.163) and Astrand protocols (-0.153 ± 3.528) for VO2max. A paired samples t-test revealed no significant differences between Novel and criterion protocols for VO2max. Paired samples t-tests revealed that the Novel protocol had significantly lower TTE when compared to the Bruce and Astrand protocols and produced similar VO2max values to that of the Bruce and Astrand. The Novel protocol may be considered a valid and time-efficient protocol.
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Exercise guidance for women with pregnancies complicated by fetal growth restriction (FGR) is vague, despite the fact that physical activity during pregnancy improves placental development, placental blood flow, and encourages healthy fetal growth. The goal of this study is to test the hypothesis that women with pregnancies complicated by FGR are fearful of physical activity and are being given unclear or limited advice from healthcare providers. Participants (N = 78) (women who delivered an infant diagnosed with FGR within the past 5 years) took an electronic survey including demographic information, pregnancy information, provider advice recall, and other health-related information relevant to growth-restricted pregnancies. Quantitative and qualitative (post-positivism paradigm) methods were employed to analyze the data. When asked specifically about how the FGR diagnosis impacted their activity levels, nearly 50% of participants said the diagnosis led them to decrease their activity levels. Participants reported that healthcare providers who do discuss activity with pregnant patients with FGR suggest low-intensity activities or ceasing activity, although the majority of providers did not discuss activity at all. More fears surrounding physical activity were reported post-FGR diagnosis, including worrying about fetal growth and development and causing fetal harm when engaging in physical activity.
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Retardo del Crecimiento Fetal , Placenta , Estudios Transversales , Ejercicio Físico , Miedo , Femenino , Humanos , Placentación , Embarazo , Estudios RetrospectivosAsunto(s)
Barrera Hematoencefálica , Encéfalo , Encéfalo/diagnóstico por imagen , Encéfalo/patología , HumanosRESUMEN
OBJECTIVE: Transcranial Focused Ultrasound (tFUS) is a promising new potential neuromodulation tool. However, the safety of tFUS neuromodulation has not yet been assessed adequately. Patients with refractory temporal lobe epilepsy electing to undergo an anterior temporal lobe resection present a unique opportunity to evaluate the safety and efficacy of tFUS neuromodulation. Histological changes in tissue after tFUS can be examined after surgical resection, while further potential safety concerns can be assessed using neuropsychological testing. METHODS: Neuropsychological functions were assessed in eight patients before and after focused ultrasound sonication of the temporal lobe at intensities up to 5760 mW/cm2. Using the BrainSonix Pulsar 1002, tFUS was delivered under MR guidance, using the Siemens Magnetom 3T Prisma scanner. Neuropsychological changes were assessed using various batteries. Histological changes were assessed using hematoxylin and eosin staining, among others. RESULTS: With respect to safety, the histological analysis did not reveal any detectable damage to the tissue, except for one subject for whom the histology findings were inconclusive. In addition, neuropsychological testing did not show any statistically significant changes in any test, except for a slight decrease in performance on one of the tests after tFUS. SIGNIFICANCE: This study supports the hypothesis that low-intensity Transcranial Focused Ultrasound (tFUS) used for neuromodulation of brain circuits at intensities up to 5760 mW/cm2 may be safe for use in human research. However, due to methodological limitations in this study and inconclusive findings, more work is warranted to establish the safety. Future directions include greater number of sonications as well as longer exposure at higher intensity levels to further assess the safety of tFUS for modulation of neuronal circuits.
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Epilepsia del Lóbulo Temporal , Epilepsia del Lóbulo Temporal/diagnóstico por imagen , Epilepsia del Lóbulo Temporal/terapia , Humanos , SonicaciónRESUMEN
ABSTRACT: Although anxiety and depression have been central topics for scholars and clinicians in the United States, few studies have examined their correlates in sub-Saharan Africa and none have examined large urban slums. Using face-to-face interviews in two African cities, we analyze self-reported symptoms of anxiety and depression in a community-based sample (n = 495). Ordinary least squares regression was used to analyze a variety of demographic and social predictors including sex, child-rearing, marital status, education, income, age, and neighborhood for residents of Agbogbloshie (Accra, Ghana) and Kangemi (Nairobi, Kenya). Controlling for other factors, two personal network dimensions were significant. Total network size is positively associated with symptoms of anxiety and depression in Kenya but not in Ghana. However, one factor was predictive of symptoms of anxiety and depression in both locations: the reported percentage of ties with older persons. Higher levels of anxiety and depression are associated with a larger share of older individuals in one's personal network.
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Ansiedad/etnología , Depresión/etnología , Familia/etnología , Áreas de Pobreza , Características de la Residencia , Red Social , Población Urbana , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Femenino , Ghana/etnología , Humanos , Kenia/etnología , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
Relationships with peers are critical for many aspects of adolescent development, including academic outcomes. Incorporating social control, social learning, and social capital theories, we investigated connections between two types of peer networks, close friends and extracurricular activity (ECA) members, and students' own academic performance. Social learning and bonding social capital perspectives posit that close friends should have a symmetrical effect, either beneficial or harmful, because they exert strong influences on adolescents. By contrast, social control and bridging/linking social capital perspectives suggest that ECA member influences should be asymmetrical as they amplify benefits from higher-performing ECA peers and minimize harmful influences from lower-performing ones. We used Add Health data to test our hypotheses. We found that the average friend GPA was positively associated (in the same direction) with student GPA, while ECA member GPAs were, as hypothesized, asymmetrically linked to student GPA. We discussed implications for educators and future research.
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Rendimiento Académico , Capital Social , Adolescente , Amigos , Humanos , Grupo Paritario , EstudiantesRESUMEN
Bacterial biofilms are highly resistant to antibiotics and have been implicated in the etiology of 60%-80% of chronic microbial infections. We tested a novel combination of low intensity ultrasound and blue light against biofilm and planktonic bacteria. A laboratory prototype was built which produced both energies uniformly and coincidently from a single treatment head, impinging upon a 4.45 cm2 target. To demonstrate proof of concept, Propionibacterium acnes biofilms were cultured on Millicell hanging inserts in 6-well plates. Hanging inserts with biofilms were treated in a custom exposure chamber designed to minimize unwanted ultrasound reflections. Coincident delivery of both energies demonstrated synergy over either alone, killing both stationary planktonic and biofilm cultures of P. acnes. Reduction in biofilm bacteria was dose dependent on exposure time (i.e., energy delivered). P. acnes biofilms were significantly reduced by dual energy treatment (p < 0.0001), with a >1 log10 reduction after a 5 min (9 J/cm2) and >3 log10 reduction after a 30 min (54 J/cm2) treatment (p < 0.05). Mammalian cells were found to be unaffected by the treatment. Both the light and the ultrasound energies are at levels previously cleared by the FDA. Therefore, this combination treatment could be used as a safe, efficacious method to treat biofilm related syndromes.
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Noninvasive low-intensity focused ultrasound pulsation (LIFUP) neuromodulation provides a unique approach to both investigating and treating the brain. This work describes a well-calibrated, simple-to-use ultrasound stimulation system for neuromodulation studies. It provides a single-element 650-kHz transducer design and a straightforward control mechanism, with extensive calibration and internal electronic monitoring to prevent unwanted over or under treatment. One goal of this approach is to relieve researchers of many of the details associated with developing their own exposure equipment. A unique transducer positioning system and distinctive MRI fiducial targets simplify alignment and targeting. The system design, control software, calibration, and alignment techniques are described in detail. Examples of transducer targeting and neurostimulation using the system are provided.
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Imagen por Resonancia Magnética , Terapia por Ultrasonido , Encéfalo/diagnóstico por imagen , Diseño de Equipo , Transductores , UltrasonografíaRESUMEN
This article introduces the plastic surgeon to the basics of high-resolution ultrasound (HRUS) for screening breast implants. It describes how HRUS has become an accepted alternative to MRI for screening and diagnosis, and how plastic surgeons should use this new technology for the benefit of their patients and their practices. Basic principles, technology, and nomenclature are presented. Key steps to obtaining diagnostic images of breast implants are reviewed, including typical artifacts and sources of error. Imaging examples are presented. The article ends with a review and a step-by-step guide for plastic surgeons looking to use the technology.
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Implantes de Mama , Mama/diagnóstico por imagen , Ultrasonografía Mamaria/métodos , Femenino , Humanos , Sensibilidad y Especificidad , Geles de Silicona , Cirujanos , Ultrasonografía Mamaria/instrumentaciónRESUMEN
Cardiorespiratory endurance is an important element of aerobic fitness, particularly in weight management and reducing risk for cardiovascular disease. While there are numerous options for aerobic exercise, rope jumping is often overlooked. In addition to regular exercise and a healthy diet, the American Heart Association strongly recommends rope jumping. The first purpose of this study was to determine the steady state metabolic cost of repetitive jumping on the Digi-Jump machine to evaluate whether exercise on this device is more or less strenuous than similar exercise with a jump rope, as demonstrated in previous literature. A second purpose was to determine the relative intensity of exercise on the Digi-Jump by comparing to VO2max as measured on a treadmill. Twenty-seven participants completed two trials, one jumping trial at a rate of 120 jumps per minute with the jumping height set at 0.5 inch for 5-min on the Digi-Jump, and one graded exercise test using the Bruce protocol. Oxygen uptake (VO2), heart rate (HR), respiratory exchange ratio (RER), and rating of perceived exertion (RPE) were measured each minute during each trial. Results of this study indicated that steady state VO2 during the 5-min jump test was reached at the 3rd min. Steady state variables during the jumping trial expressed as percentage of max were as follows: VO2 was 57.1% of VO2max; HR was 80.9% of HRmax; RER was 86%of RERmax; and RPE was 75.2% of RPEmax. These data indicate that repetitive jumping is a strenuous activity and similar in intensity to jumping rope, even if the trial is done on the Digi-Jump machine with free-swinging arms and without a jump rope.