Ultrasound Waves Research Articles

Picosecond photoacoustic generation of ultrasounds with composites of graphene-decorated gold nanoparticles

Photoacoustic or light-to-pressure transducer materials exhibit tremendous potential across various disciplines and applications, embracing theragnostic ultrasounds and permeabilization of biological barriers for drug delivery or for gene transfection. Here, we report the photoacoustic response in the picosecond excitation regime of graphene and gold nanoparticles decorated graphene dispersed in a polydimethylsiloxane polymer matrix. A novel decoration method was developed to nucleate Au nanoparticles of 25 nm on the graphene surface without reducing agent. We observed that the picosecond excitation enforced by the stress confinement generates high-frequency waves, with bandwidths of −6 dB and −20 dB of around 70 MHz and 130 MHz respectively, and peak pressure > 5 MPa. Further, the presence of gold surface decoration leads to a better dispersibility of the flake into the polymer matrix and to an increasing bandwidth at −6 dB up to 85 MHz. The decrease in source thickness leads to an increase in ultrasound frequency, which retains its value even when the laser fluence is increased up to 150 mJ cm –2. This enables the generation of high pressures while keeping the same bandwidth. We experimentally show that the photoacoustic waveform can be tailored by changing the temporal duration of the laser light, the geometry of the acoustic source, and the nature of the graphene absorber. Flexible decoration and fabrication methods of thin films, along with the generation of high-frequency and high-pressure ultrasound waves, offer new perspectives for the use of physical methods to permeabilize biological barriers and develop high-resolution photoacoustic imaging systems.

Nonlinear three-dimensional modeling for encapsulated microbubble dynamics subject to ultrasound

Encapsulated microbubbles (EMBs) stabilized by thin coatings have been used as contrast agents for ultrasound sonography as well as having been demonstrated as a promising new technology for targeted drug delivery. The dynamics of EMBs is three-dimensional (3D) because EMBs within micro-vessels inevitably interact with boundaries, but the theoretical and numerical studies are limited to spherical, weakly non-spherical, and/or axisymmetric EMBs. Here, we have developed physical, mathematical, and numerical models for nonlinear 3D EMB dynamics. The liquid flow is evaluated using the boundary integral method. The EMB coating is modeled as a thin viscoelastic shell including stretching, bending, and shear effects and simulated using the finite element method. These models are coupled through the kinematic and dynamic boundary conditions at the interface. The model is in good agreement with the Hoff equation for spherical EMBs and the asymptotic theory for weakly non-spherical deformation of EMBs. Using this model, a numerical study for EMB dynamics near a rigid boundary subject to an ultrasonic wave is performed. The migration, non-spherical oscillation, resonant oscillation, and jetting of EMBs are displayed and analyzed systematically. If the ultrasound wave is strong, a high-speed liquid jet forms at the final stage of the collapse, orientated between the directions of the wave and toward the wall. The EMB jet is weaker and slower and has less momentum, as the non-spherical deformation of the coating and the jetting are suppressed by the viscoelastic property of the coating. If the ultrasound is not strong, the EMB remains spherical for many cycles of oscillation but the EMB undergoes resonant oscillation and becomes significantly non-spherical after several oscillation cycles, when the wave frequency is equal to its natural frequency. The numerical capability has the potential to be developed for the optimization of sonography or drug delivery.

Ultrasonic evaluation of wire arc additively manufactured parts with heterogeneous microstructure

Abstract In Wire Arc Additive Manufacturing (WAAM) components manufactured by gas metal arc welding strategy, periodically alternating patterns of fine- and coarse-grained microstructures develop along the building direction, depending on the temperature evolution. Ultrasonic non-destructive evaluation relies on the scattering of waves from defects. In the material microstructure, ultrasound waves are also scattered at the grain boundaries as grain noise. The work presents a study on the influence of heterogeneous microstructure in WAAM on defect detectability during ultrasonic inspections. The study used a 2D finite element model to simulate ultrasound wave propagation in the material microstructure represented by a surface element from electron backscatter diffraction scans. Side-drilled holes were introduced in the material as defects. Phased array was used to perform full matrix capture and obtain ultrasound image through total focusing method, with dynamic focusing capability to inspect the heterogeneous microstructure. The study analysed the defect echoes and noises using the signal-to-noise ratio (SNR) to assess its defect detectability. While defects were well detected, the SNR values differ by 10% for defects at various positions along the building and transverse directions in the heterogeneous microstructure.

Influence of ultrasound-assisted extraction on the pectin extraction yield and structural characteristics: A case study on carrot pomace (Daucus carota)

For the ultrasound-assisted extraction (UAE) of pectin from carrot pomace, the influence of different extraction parameters on the pectin yield and structure was studied. Therefore, an Orthogonal Minimally Aliased Response Surface (OMARS) design and a constant extraction temperature were used. This study showed that pH had the most pronounced effect on the pectin yield and molecular structure, and that a low pH is crucial to liberate pectin from the cell wall matrix. Besides, it was shown that an increased pectin yield can be achieved with an increased ultrasound intensity, provided that the pH is sufficiently low. The optimal UAE conditions resulted in a pectin yield of 57.2 %, while the control extraction, which used the same extraction conditions without the application of ultrasound waves, only resulted in a pectin yield of 37.4 %, showing a significant increase with ultrasonication. Due to the temperature-control during the ultrasonication process, this increased yield can be attributed to the ultrasound waves as such, and not to the accompanying temperature increase. Additionally, shorter extraction times can be used to obtain pectin yields comparable to a conventional acid extraction process. These increased yields and shorter extraction processes show the potential of UAE as an alternative extraction technology.

Industrial park wastewater treatment using a combined sono-pulsed electrochemical-coagulation process

Maintaining sustainable water management practices, preserving ecosystems, and safeguarding public health has depend on the treatment of wastewater. It has a significant impact on reducing water pollution and protecting the water supplies. Sono-pulsed electrochemical oxidation (S-PEO) process is a wastewater treatment method that uses ultrasound (US) waves and electrochemistry to enhance the pollutant removal efficiency. This study aim is to investigate the mineralization of industrial park wastewater by using pulsed electrochemical oxidation (PEO) and a combination of sonolysis and pulsed electrochemical oxidation (S-PEO) processes. The research focuses on the percentage elimination of chemical oxygen demand (COD) and color, as well as the assessment of power consumption. The study considers the influence of experimental parameters like initial pH, electrolysis time, and current to find the optimum conditions for maximum percentage removal efficiency with minimization of power consumption. According to the study, the optimum values of responses for the S-PEO process were obtained at pH=7, electrolysis time=40 min, and current =0.5 Amp. The optimum values for the maximum removal percentages of the responses COD and color were 97.04 %, and 99.70 %, respectively. The minimum of power consumption for S-PEO was 0.19 kWh/m3. These results demonstrate that, the superior efficiency of the S-PEO process and its feasibility in the removal of industrial wastewater pollutants. Optimizing parameters like pH, time, and current intensity is crucial for optimal performance, reducing energy consumption and operational costs. The S-PEO technique eliminates pollutants from wastewater efficiently and effectively, making it the suitable process when compared to the others.

Sonodynamic therapy for adult-type diffuse gliomas: past, present, and future.

Intra-axial brain tumors persist as significant clinical challenges. Aggressive surgical resection carries risk of morbidity, and the blood-brain barrier (BBB) prevents optimal pharmacological interventions. There is a clear clinical demand for innovative and less invasive therapeutic strategies for patients, especially those that can augment established treatment protocols. Focused ultrasound (FUS) has emerged as a promising approach to manage brain tumors. Sonodynamic therapy (SDT), a subset of FUS, utilizes sonosensitizers activated by ultrasound waves to generate reactive oxygen species (ROS) and induce tumor cell death. This review explores the historical evolution and rationale behind SDT, focusing on its mechanisms of action and potential applications in brain tumor management. A systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Preclinical studies have demonstrated the efficacy of various sonosensitizers, including 5-aminolevulinic acid (5-ALA), fluorescein, porphyrin derivatives, and nanoparticles, in conjunction with FUS for targeted tumor therapy and BBB disruption. Clinical trials have shown promising results in terms of safety and efficacy, although further research is needed to fully understand the potential adverse effects and optimize treatment protocols. Challenges such as skull thickness affecting FUS penetration, and the kinetics of BBB opening require careful consideration for the successful implementation of SDT in clinical practice. Future directions include comparative studies of different sonosensitizers, optimization of FUS parameters, and exploration of SDT's immunomodulatory effects. SDT represents a promising frontier in the treatment of aggressive brain tumors, offering hope for improved patient outcomes.

Validity of Elastic Imaging Evaluation of Hamstring Muscles With Knee Contracture Using Ultrasound Shear Wave Elastography.

This study used ultrasound shear wave elastography (SWE) to evaluate the mechanical properties of hamstring muscles from cadaveric specimens with knee flexion contractures. Hamstring muscles for tensile testing were harvested from Thiel soft-embalmed cadavers with and without knee flexion contracture. Muscle specimens were mounted on a testing machine. The initial load detected when a tensile load was applied to the distal end was used as the slack length. The cross-sectional areas of the muscle at slack length were measured at the proximal and distal sites using B-mode ultrasonography. Subsequently, the muscle specimen was elongated from the slack length to 8% strain, with the shear modulus measured using SWE. Young's modulus (stress/strain) was calculated based on the displacement and tensile force obtained from the tensile test. Regression analysis showed a significant positive linear relationship between the Young's and shear moduli for all specimens at all the sites (P < 0.01 and coefficient of determination: 0.95-0.99). The Young's and average shear moduli at the proximal and distal sites were higher in all hamstring muscles with contractures than in those without contractures. SWE can be used to estimate Young's moduli of hamstring muscles with contractures. Muscle specimens with contractures exhibited higher resistance to elongation, thereby indicating that their mechanical properties differed from those of muscles without contractures.

Acoustic deep brain modulation: Enhancing neuronal activation and neurogenesis

BackgroundNon-invasive deep brain modulation (DBM) stands as a promising therapeutic avenue to treat brain diseases. Acoustic DBM represents an innovative and targeted approach to modulate the deep brain, employing techniques such as focused ultrasound and shock waves. Despite its potential, the optimal mechanistic parameters, the effect in the brain and behavioral outcomes of acoustic DBM remains poorly understood. ObjectiveTo establish a robust protocol for the shock wave DBM by optimizing its mechanistic profile of external stimulation, and to assess its efficacy in preclinical settings. MethodsWe used shockwaves due to their capacity to leverage a broader spectrum of peak intensity (10–127 W/mm2) in contrast to ultrasound (0.1–5.0 W/mm2), thereby enabling a more extensive range of neuromodulation effects. We established various types of shockwave pressure profiles of DBM and compared neural and behavioral responses. To ascertain the anticipated cause of the heightened neural activity response, numerical analysis was employed to examine the mechanical dynamics within the brain. ResultsAn optimized profile led to an enhancement in neuronal activity within the hypothalamus of mouse models. The optimized profile in the hippocampus elicited a marked increase in neurogenesis without neuronal damage. Behavioral analyses uncovered a noteworthy reduction in locomotion without significant effects on spatial memory function. ConclusionsThe present study provides an optimized shock wave stimulation protocol for non-invasive DBM. Our optimized stimulation profile selectively triggers neural functions in the deep brain. Our protocol paves the way for new non-invasive DBM devices to treat brain diseases.

Bragg grating etalon-based optical fiber for ultrasound and optoacoustic detection

Fiber-based interferometers receive significant interest as they lead to miniaturization of optoacoustic and ultrasound detectors without the quadratic loss of sensitivity common to piezoelectric elements. Nevertheless, in contrast to piezoelectric crystals, current fiber-based ultrasound detectors operate with narrow ultrasound bandwidth which limits the application range and spatial resolution achieved in imaging implementations. We port the concept of silicon waveguide etalon detection to optical fibers using a sub-acoustic reflection terminator to a Bragg grating embedded etalon resonator (EER), uniquely implementing direct and forward-looking access to incoming ultrasound waves. Precise fabrication of the terminator is achieved by continuously recording the EER spectrum during polishing and fitting the spectra to a theoretically calculated spectrum for the selected thickness. Characterization of the EER inventive design reveals a small aperture (10.1 µm) and an ultra-wide bandwidth (160 MHz) that outperforms other fiber resonators and enables an active detection area and overall form factor that is smaller by more than an order of magnitude over designs based on piezoelectric transducers. We discuss how the EER paves the way for the most adept fiber-based miniaturized sound detection today, circumventing the limitations of currently available designs.

Assessment of perianal fistulizing Crohn's disease activity with endoanal ultrasound: A retrospective cohort study.

Perianal fistulas pose dual challenges to Crohn's disease (CD) patients. Low patient compliance due to the complexity of existing examination methods plagues the treatment and follow-up management of perianal CD. To determine the accuracy of endoanal ultrasound (EUS) and shear wave elastography (SWE) for evaluating perianal fistulizing CD (PFCD) activity. This was a retrospective cohort study. A total of 67 patients from August 2022 to December 2023 diagnosed with CD were divided into three groups: Non-anal fistula group (n = 23), low-activity perianal fistulas [n = 19, perianal disease activity index (PDAI) ≤ 4], high-activity perianal fistulas (n = 25, PDAI > 4) based on the PDAI. All patients underwent assessments including EUS + SWE, pelvic magnetic resonance [pelvic magnetic resonance imaging (MRI)], C-reactive protein, fecal calprotectin, CD activity index, PDAI. The percentage of fistulas indicated by pelvic MRI and EUS was consistent at 82%, and there was good consistency in the classification of perianal fistulas (Kappa = 0.752, P < 0.001). Significant differences were observed in the blood flow Limberg score (χ 2 = 8.903, P < 0.05) and shear wave velocity (t = 2.467, P < 0.05) between group 2 and 3. Shear wave velocity showed a strong negative correlation with magnetic resonance novel index for fistula imaging in CD (Magnifi-CD) score (r = -0.676, P < 0.001), a weak negative correlation with the PDAI score (r = -0.386, P < 0.05), and a weak correlation between the Limberg score and the PDAI score (r = 0.368, P < 0.05). EUS combined with SWE offers a superior method for detecting and quantitating the activity of perianal fistulas in CD patients. It may be the ideal tool to assess PFCD activity objectively for management strategies.

Enhancing sonothrombolysis outcomes with dual-frequency ultrasound: Insights from an in silico microbubble dynamics study

Sonothrombolysis is a technique that employs the ultrasound waves to break down the clot. Recent studies have demonstrated significant improvement in the treatment efficacy when combining two ultrasound waves of different frequencies. Nevertheless, the findings remain conflicted on the ideal frequency pairing that leads to an optimal treatment outcome. Existing experimental studies are constrained by the limited range of frequencies that can be investigated, while numerical studies are typically confined to spherical microbubble dynamics, thereby restricting the scope of the analysis. To overcome this, the present study investigated the microbubble dynamics caused by the different combinations of ultrasound frequencies. This was carried out using computational modelling as it enables the visualisation of the microbubble behaviour, which is difficult in experimental studies due to the opacity of blood. The results showed that the pairings of two ultrasound waves with low frequencies generally produced stronger cavitation and higher flow-induced shear stress on the clot surface. However, one should avoid the frequency pairings that are integer multipliers of each other, i.e., frequency ratio of 1/3, 1/2 and 2, as they led to resultant wave with low pressure amplitude that weakened the cavitation. At 0.5 + 0.85 MHz, the microbubble caused the highest shear stress of 60.5 kPa, due to its large translational distance towards the clot. Although the pressure threshold for inertial cavitation was reduced using dual-frequency ultrasound, the impact of the high-speed jet can only be realised when the microbubble travelled close to the clot. The results obtained from the present study provide groundwork for deeper understanding on the microbubble dynamics during dual-frequency sonothrombolysis, which is of paramount importance for its optimisations and the subsequent clinical translation.

EVALUATION OF FOCAL BREAST LESIONS USING ULTRASOUND ELASTOGRAPHY

Breast lesions pose a significant diagnostic challenge, necessitating advanced imaging techniques for accurate characterization. Ultrasound elastography, including strain and shear wave methods, offers promising diagnostic capabilities for distinguishing between benign and malignant breast lesions. Objective: This study aimed to evaluate the effectiveness of ultrasound elastography in characterizing focal breast lesions and to compare the diagnostic performance of strain and shear wave elastography techniques. Methods: A prospective observational study was conducted, enrolling 200 women aged 18 and older with focal breast lesions detected on conventional ultrasound. Participants underwent both strain and shear wave elastography. Lesion characteristics, including stiffness scores and echogenicity, were documented. Histopathological analysis was performed on biopsied lesions to confirm diagnoses. Diagnostic accuracy metrics were calculated for both elastography techniques, including sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Results: The average age of participants was 52 ± 10 years. Most lesions were solid (70%), with an average size of 22 mm. Shear wave elastography exhibited higher stiffness scores (average 4.5) than strain elastography (average 3.2). Diagnostic accuracy for benign lesions showed a sensitivity of 85% and specificity of 90% with elastography. For malignant lesions, sensitivity was 90% and specificity was 85%. The ROC curve analysis indicated the superior performance of shear wave elastography with an AUC of 0.85 compared to 0.80 for strain elastography. Conclusion: Ultrasound elastography, particularly shear wave elastography, demonstrates high diagnostic accuracy in characterizing breast lesions, providing valuable support in clinical decision-making.

Effects of Ultrasonication in Water and Isopropyl Alcohol on High-Crystalline Cellulose: A Fourier Transform Infrared Spectrometry and X-ray Diffraction Investigation.

This paper investigates the effects of ultrasonication on cellulose microparticles in different conditions. FTIR (Fourier transformed infrared spectrometry) and XRD (X-ray diffraction) analyses were used to compare the changes in the cellulose microstructure caused by the following various ultrasonic treatment conditions: time, amplitude of generated ultrasound waves, output power converted into ultrasound, the liquid medium (water and isopropyl alcohol) used for ultrasonication, and the shape of the vessel used for sonication. The cumulative results lead to an increase in the crystalline region directly proportional to the condition of sonication. Also, the total crystallinity index varied from 1.39 (pristine cellulose) to 1.94 for sonication in alcohol to 0.56 for sonication in water. The crystallinity index varied from 67% (cellulose) to 77% for the sample with 15 min of sonication in isopropyl alcohol and 50.4% for the sample with 15 min of sonication in water.

Focused Ultrasound: Noninvasive Image-Guided Therapy.

Invasive open surgery used to be compulsory to access tumor mass to perform excision or resection. Development of minimally invasive laparoscopic procedures followed, as well as catheter-based approaches, such as stenting, endovascular surgery, chemoembolization, brachytherapy, which minimize side effects and reduce the risks to patients. Completely noninvasive procedures bring further benefits in terms of reducing risk, procedure time, recovery time, potential of infection, or other side effects. Focusing ultrasound waves from the outside of the body specifically at the disease site has proven to be a safe noninvasive approach to localized ablative hyperthermia, mechanical ablation, and targeted drug delivery. Focused ultrasound as a medical intervention was proposed decades ago, but it only became feasible to plan, guide, monitor, and control the treatment procedures with advanced radiological imaging capabilities. The purpose of this review is to describe the imaging capabilities and approaches to perform these tasks, with the emphasis on magnetic resonance imaging and ultrasound. Some procedures already are in clinical practice, with more at the clinical trial stage. Imaging is fully integrated in the workflow and includes the following: (1) planning, with definition of the target regions and adjacent organs at risk; (2) real-time treatment monitoring via thermometry imaging, cavitation feedback, and motion control, to assure targeting and safety to adjacent normal tissues; and (3) evaluation of treatment efficacy, via assessment of ablation and physiological parameters, such as blood supply. This review also focuses on sonosensitive microparticles and nanoparticles, such as microbubbles injected in the bloodstream. They enable ultrasound energy deposition down to the microvascular level, induce vascular inflammation and shutdown, accelerate clot dissolution, and perform targeted drug delivery interventions, including focal gene delivery. Especially exciting is the ability to perform noninvasive drug delivery via opening of the blood-brain barrier at the desired areas within the brain. Overall, focused ultrasound under image guidance is rapidly developing, to become a choice noninvasive interventional radiology tool to treat disease and cure patients.

Shear Wave Elastography of the Skin following Radial Forearm Free Flap Surgery in Transgender Patients: Observational Study.

Background: Ultrasound shear wave elastography (SWE) noninvasively measures the stiffness of tissue by producing and measuring tissue deformation. Scar formation, a crucial aspect of wound healing, can lead to functional and aesthetic complications when pathological. While SWE has shown promise in dermatological evaluations, its role in surgical scar assessment remains underestimated. Our study aims to investigate SWE in evaluating surgical scars at the donor site after forearm free flap surgery in transgender patients. Methods: After radial forearm free flap harvesting, the donor site was grafted with a split-thickness skin graft with or without interposition of Matriderm. Eleven patients were evaluated more than one year after surgery, using SWE alongside scar characteristics, sensory outcomes, and patient satisfaction surveys. Results: Our study revealed no significant difference in stiffness (p > 0.15), pigmentation (p = 0.32), or erythema (p = 0.06) between operated and non-operated sides. The interposition of Matriderm did not influence the stiffness. Patients significantly (p < 0.0001) reported a loss of discrimination. Patients' subjective scar evaluation appeared in line with our quantitative and objective results. Conclusions: This study contributes to the evolving understanding of SWE's role in scar assessment, highlighting its feasibility in evaluating surgical scars. However, continued research efforts are necessary to establish SWE as a reliable and objective method for surgical scar evaluation and management.

Ultrasound Shear Wave Elastography for Noninvasive Diagnosis of Acute Compartment Syndrome Using a Novel In Vivo Turkey Model.

Acute Compartment Syndrome (ACS) is a severe trauma caused by elevated intra-muscle-compartment pressure (ICP). The current standard method for diagnosis is to insert a needle into the muscle sterilely under anesthesia. However, to secure the environment is sometimes not easy and leads to delays in diagnosis. Recently, we have focused on shear wave ultrasound elastography (SWE) as an alternative, which can be done concisely in unclean environment and without anesthesia. We would like to report the usefulness of SWE for ACS diagnosis using 2-pedal walking turkey model recently developed in our lab. A total of 32 1-year-old Bourbon turkeys were used. 5% solution of chicken albumin was infused continuously into the tibialis cranialis (TC) muscle using IV pump. The ICP was increased stepwise from 0 to 50 mmHg. During the rising of ICP, the correlation between values of SWE (kPa) and ICP (mmHg) was measured. After the ICP reached 50 mmHg, half of the turkeys were maintained at this pressure for 2 hours and the rest for 6 hours. After infusion, a fasciotomy was performed on the half turkey. Half of the turkeys were euthanized after 2 weeks and the rest after 6 weeks. SWE of TC muscle and walking gait data on turkeys using a portable walkway system were measured weekly until euthanasia. At euthanasia, isometric tetanic muscle force (ITF) tests to TC muscle and histological evaluations were performed. SWE value (kPa) was highly significantly correlated to the actual ICP (mmHg) (R2 = 0.91). Stance of ACS side leg were significantly extended, and swing of the control side shortened from the second to the third week after ACS in the 6 hours infusion-no-fasciotomy group (P < 0.05*). ITF was significantly reduced mainly in the 6 hours infusion group (P < 0.05*). Histological evaluation revealed that in the 6 hours infusion and 6 weeks survival group, both the muscle fiber and intercellular distances were significantly expanded (P < 0.05). SWE seems to be a substitute measure of ICP in diagnosing ACS. With regard to our in vivo ACS model using turkey, survival at 50 mmHg ICP for 6 hours and 6 weeks post ACS would be an appropriate situation.

Direct Sonochemical Leaching of Li, Co, Ni, and Mn from Mixed Li-Ion Batteries with Organic Acids

Metals such as nickel, cobalt, lithium, and manganese are widely used in lithium-ion batteries (LIBs) in electronic devices and electric vehicles. It is forecast that there will be a strong increase in the number of electronic devices and electric vehicles in the coming years. (1) Background: In this paper, the application of ultrasound waves on improving Li, Co, Mn, and Ni leaching efficiency from mixed active cathode materials from different types of LIBs is presented. (2) Methods: Environmentally friendly, low-concentrated (0.75 M) organic acids (oxalic acid, citric acid) and, additionally, sulfuric acid, were used in sonochemical and chemical leaching (stirring process) at a temperature of 60 °C. (3) Results: The results showed significantly higher leaching efficiency of metals with ultrasound-assisted treatment, especially when using organic acids. An average of 50% better leaching results were obtained for Li in oxalic acid (99.6%) and for Co (93.1%) in citric acid during sonochemical leaching. (4) Conclusions: Based on the theory of hydrogen peroxide formation during ultrasound wave transition in solutions, the role of H2O2 as one of the most effective reductants used to enhance cobalt, manganese, and nickel leaching from LIBs is indicated.

Predicting ultrasound wave stimulated bone growth in bioinspired scaffolds using machine learning

For conditions like osteoporosis, changes in bone pore geometry even when porosity is constant have been shown to correlate to increased fracture risk using techniques such as dual-energy x-ray absorptiometry (DXA) and computed tomography (CT). Additionally, studies have found that bone pore geometry can be characterized by ultrasound to determine fracture risk, since certain pore geometries can cause stress concentration which in turn will be a source for fracture. However, it is not yet fully understood if changes in pore geometry can be detected by ultrasound when the porosity is constant. Therefore, this study develops an unsupervised machine learning model classifying pore geometry between bioinspired and quadrilateral pore scaffolds with constant porosity using experimental ultrasound wave transmission data. Our results demonstrate that differences in pore geometry can be detected by ultrasound, even at constant porosity, and that these differences can be distinguished in an unsupervised manner with machine learning. For traumatic bone injuries and late-stage osteoporosis where fracture occurs, tissue scaffolds are used to aid the healing of fractures or bone loss. The scaffold design is optimized to match material properties closely with bone, and healing can be enhanced with ultrasound stimulation. In this study we predict the combined effects of ultrasound parameters, such as wave frequency and mode of displacement, and scaffold material properties on bone tissue growth. We therefore develop an unsupervised machine learning clustering model of bone tissue growth in the scaffolds using finite element analysis and bone growth algorithms evaluating effects of pore geometry, scaffold materials, ultrasound wave type and frequency, and mesenchymal stem cell distribution on bone tissue growth. The computational predictions of tissue growth agreed within 10% of comparable experimental studies. The data corresponding to pore geometry, mesenchymal stem cell distribution, and scaffold material demonstrate distinct clusters of total bone formation, while ultrasound frequency and mesenchymal stem cell distribution show distinct clusters in bone growth rate. These variables can be tuned to tailor the scaffold design and optimize the required amount and rate of bone growth to meet a patient's specific needs.

Ultrasound of the bowel with a focus on IBD: the new best practice.

Inflammatory Bowel Disease (IBD) is a lifelong chronic disease affecting any part of the gastrointestinal tract with a predilection for the terminal ileum. IBD patients require repeat imaging throughout the course of their disease, necessitating a safe, noninvasive, available, and repeatable method. Imaging is required at diagnosis, routine surveillance, and acute exacerbation of disease. Ultrasound imaging meets these demands with a high degree of accuracy and wide patient acceptance. Ultrasound provides high-resolution imaging and is excellent for detailed evaluation of the bowel wall and surrounding soft tissues. Regular greyscale bowel evaluation and color Doppler imaging now have accepted standards for evaluating disease activity based on wall thickness, perienteric inflammatory fat, and blood flow, which is invaluable in staging and grading disease. High-resolution dynamic real-time imaging on ultrasound has the ability to show functional as well as morphologic detail, including dysfunctional peristalsis associated with bowel stricture and incomplete mechanical bowel obstruction. Fibrostenotic and penetrating complications of IBD may be associated with an acute or chronic presentation that is easily assessed using ultrasound. Newer software technologies for ultrasound, including Contrast-Enhanced ultrasound and Shear wave elastography, have transformed ultrasound from a basic preliminary imaging technique into a highly sophisticated modality that is now competitive with CT and MR enterography for managing IBD patients. Our long experience with ultrasound of the bowel suggests that the new best practice would include ultrasound as the first test for evaluation of the bowel at any stage of the disease.

Ultrasound-Mediated Antibiotic Delivery to In Vivo Biofilm Infections: A Review.

Bacterial biofilms are a significant concern in various medical contexts due to their resilience to our immune system as well as antibiotic therapy. Biofilms often require surgical removal and frequently lead to recurrent or chronic infections. Therefore, there is an urgent need for improved strategies to treat biofilm infections. Ultrasound-mediated drug delivery is a technique that combines ultrasound application, often with the administration of acoustically-active agents, to enhance drug delivery to specific target tissues or cells within the body. This method involves using ultrasound waves to assist in the transportation or activation of medications, improving their penetration, distribution, and efficacy at the desired site. The advantages of ultrasound-mediated drug delivery include targeted and localized delivery, reduced systemic side effects, and improved efficacy of the drug at lower doses. This review scrutinizes recent advances in the application of ultrasound-mediated drug delivery for treating biofilm infections, focusing on in vivo studies. We examine the strengths and limitations of this technology in the context of wound infections, device-associated infections, lung infections and abscesses, and discuss current gaps in knowledge and clinical translation considerations.