Coupling Gel Research Articles

The Value of First-Order Features Based on the Apparent Diffusion Coefficient Map in Evaluating the Therapeutic Effect of Low-Intensity Pulsed Ultrasound for Acute Traumatic Brain Injury With a Rat Model.

PurposeIn order to evaluate the neuroprotective effect of low-intensity pulsed ultrasound (LIPUS) for acute traumatic brain injury (TBI), we studied the potential of apparent diffusion coefficient (ADC) values and ADC-derived first-order features regarding this problem.MethodsForty-five male Sprague Dawley rats (sham group: 15, TBI group: 15, LIPUS treated: 15) were enrolled and underwent magnetic resonance imaging. Scanning layers were acquired using a multi-shot readout segmentation of long variable echo trains (RESOLVE) to decrease distortion. The ultrasound transducer was applied to the designated region in the injured cortical areas using a conical collimator and was filled with an ultrasound coupling gel. Regions of interest were manually delineated in the center of the damaged cortex on the diffusion weighted images (b = 800 s/mm2) layer by layer for the TBI and LIPUS treated groups using the open-source software ITK-SNAP. Before analysis and modeling, the features were normalized using a z-score method, and a logistic regression model with a backward filtering method was employed to perform the modeling. The entire process was completed using the R language.ResultsDuring the observation time, the ADC values ipsilateral to the trauma in the TBI and LIPUS groups increased rapidly up to 24 h. After statistical analysis, the 10th percentile, 90th percentile, mean, skewness, and uniformity demonstrated a significant difference among three groups. The receiver operating characteristic curve (ROC) analysis shows that the combined LR model exhibited the highest area under the curve value (AUC: 0.96).ConclusionThe combined LR model of first-order features based on the ADC map can acquire a higher diagnostic performance than each feature only in evaluating the neuroprotective effect of LIPUS for TBI. Models based on first-order features may have potential value in predicting the therapeutic effect of LIPUS in clinical practice in the future.

Disinfection of Ultrasound Transducers Using Non-Sterile Tissue Paper in Some Low-Cost Private Ultrasound Centres in Nigeria – Implications for Nosocomial Infection Management

Background/Aims: The incidence of disease outbreaks in clinical settings arising from ultrasound examinations is well documented, and is a source of worry. The ultrasound transducers and the coupling gel are potential sources of these infections since they come in direct contact with the patient’s skin. In this study, we examine the efficacy of the widespread practice of the use of plain non-sterile tissue paper in some low cost private ultrasound centres in our locality as a method of disinfecting ultrasound transducers after each use. Its potential impact on nosocomial infection management in clinical practice is also examined. Methods: Swab samples from convex ultrasound transducers before and after transabdominal scanning of three consecutive patients were obtained from 10 different ultrasound centres in urban and rural areas of Enugu state. Ultrasound coupling gel samples were equally obtained, and all samples cultured for bacteria growth which was quantified in colony forming units per ml (cfu/ml) and reported in 1000/ml. Paired sampled t-test was used to check for significance in reduction in bacterial load before and after the transducer was cleaned.Results: Nine different bacterial strains were isolated. Staphylococcus aureus and Klebsiella spp had the highest percentage of occurrence in all centres. Significant bacteria growth was recorded in the morning before the examination, and plain tissue paper significantly reduced the bacteria load in the ultrasound transducer.Conclusion: Even though disinfecting ultrasound transducers with non-sterile plain tissue paper alone is statistically effective and has the potential to minimize nosocomial infection, it is however not clinically effective and hence not advised.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Neonatal and Infant Spine.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Neonatal and Infant Spine.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Extracranial Cerebrovascular System.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Extracranial Cerebrovascular System.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Abdomen and/or Retroperitoneum.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Abdomen and/or Retroperitoneum.

Trans-orbital sonographic assessment of optic nerve diameter in a sampled Nigerian population

Background: Studies have reported variants in the dimensions of optic nerve diameter among different ethnic groups, just as other body anatomy differs from regions to regions.Aim: To establish normal range of optic nerve diameter in a sampled Nigerian population, sonographically.Materials and Method: A total of 725 apparently healthy adult subjects (362 males aged 32 to 65 years and 363 females aged 30 to 68 years) were recruited from the South South and South Eastern parts of Nigeria for this prospective descriptive study. The optic nerve diameter (OND) was measured using a high-resolution digital dedicated small-parts real time ultrasound machine (Sonoace 5500; Medicol, Medison, Miami, FL, USA) with a high frequency (10-MHz) linear array transducer. Subjects were in supine position and were asked to keep their eyes closed and still. Coupling gel was placed on the closed eye lid with the transducer softly placed over the upper temporal eyelid in an axial plane. The OND was measured perpendicular to the vertical axis of the scanning plane as a horizontal distance between the two walls of the nerve sheath. The height and weight of the subjects were determined using a meter rule and a weighing scale.Results: The mean optic nerve sheath diameter of males and females was 4.2 ± 0.13 mm. It ranged from 4.0 to 4.45 mm. The optic nerve sheath diameter of males was not significantly different from that of females (p = 0.345). No significant difference between the mean OND of both eyes (p = 0.345). Body mass index and age did not have any association with OND (r = 0.017, 0.034), the data were normally distributed.Conclusion: Optic nerve diameter of apparently normal Nigerian adults ranges from 4.0 to 4.5 mm. Values outside this range may demand further evaluation in the study population.

Acrylate pressure-sensitive adhesives tape as cover membrane for preventing ultrasound probes from cross-infections

Ultrasonic diagnosis is convenient and effective. However, insufficient and improper cleaning or disinfection will not only cause cross-infection, but also damage the outermost acoustic lens which is the most critical acoustic part of the medical ultrasonic imaging system. Herein, acrylate pressure-sensitive adhesive (PSA) tapes, intended as coverings for protecting ultrasound probes to prevent cross-infections, were prepared by the transfer coating method using acrylate copolymer as the adhesive and polyethylene film as the substrate. Ultrasound testing using PSA tape as a barrier for the probe was carried out on a skin-like silicone puncture phantom and the distal forearm of a volunteer. The clarity of ultrasonic images analyzed by Image J Software based on gray value and judged by the clinician was compared. Effect of acrylate copolymers with different molecular weights synthesized through free radical polymerization by adjusting the amount of solvent (ethyl acetate) and crosslinker (aluminum acetylacetonate) on adhesive properties and clarity of ultrasonic images were investigated in detail. Results showed that the shear strength of PSA tapes improved with increasing molecular weight of acrylate copolymer, however, tack and 180° peel strength showed a downward trend. The formation of a cross-linked network among polymer chains also greatly improved the shear strength of PSA tapes to meet the requirements of ultrasound probe covers, such as ‘easy to adhere and peel from the ultrasound probe’, ‘without adhesive residue on the surface of the ultrasound probe’ and ‘less impact on the clarity of ultrasonic images’. Viscoelastic adhesive layer of tape replaces the coupling gel between ultrasound probe and PSA tape. The ease of preparation, convenience of use, and effectiveness of acrylate PSA tapes indicate that they have broad application prospects for sonographic examinations.

Study of the Optimal Waveforms for Non-Destructive Spectral Analysis of Aqueous Solutions by Means of Audible Sound and Optimization Algorithms

Acoustic analysis of materials is a common non-destructive technique, but most efforts are focused on the ultrasonic range. In the audible range, such studies are generally devoted to audio engineering applications. Ultrasonic sound has evident advantages, but also severe limitations, like penetration depth and the use of coupling gels. We propose a biomimetic approach in the audible range to overcome some of these limitations. A total of 364 samples of water and fructose solutions with 28 concentrations between 0 g/L and 9 g/L have been analyzed inside an anechoic chamber using audible sound configurations. The spectral information from the scattered sound is used to identify and discriminate the concentration with the help of an improved grouping genetic algorithm that extracts a set of frequencies as a classifier. The fitness function of the optimization algorithm implements an extreme learning machine. The classifier obtained with this new technique is composed only by nine frequencies in the (3–15) kHz range. The results have been obtained over 20,000 independent random iterations, achieving an average classification accuracy of 98.65% for concentrations with a difference of ±0.01 g/L.

Ultrasound-guided regional anesthesia in COVID-19 and future pandemics: infection control.

Purpose of reviewInfection control is inherent in ultrasound-guided regional anesthesia practice, because ultrasound transducer and coupling gel can be vectors for pathogen transmission. We reviewed the current standards and recommendations of ultrasound transducer cleaning, disinfection, and safe handling of ultrasound equipment. Based on the available data, we propose a set of practical recommendations applicable to coronavirus disease 2019 (COVID-19) pandemic and future epidemics.Recent findingsRegional anesthesia is often preferred over general anesthesia for COVID-19 patients. Avoidance of general anesthesia reduces the need for aerosol generating procedures. Administration of ultrasound-guided regional anesthesia and surgery under regional anesthesia in COVID-19 patients requires careful infectious precautions to prevent the viral spread through the use equipment.SummaryUltrasound machine, transducer and coupling gel can serve as a vector for transmission of pathogens. In the era of COVID-19 pandemic, standardized strategies are recommended to minimize the risk of spread of COVID-19 to both patients and the healthcare providers.

A rigid-flexible coupling gel polymer electrolyte towards high safety flexible Li-Ion battery

Presently, the commercial applications of gel polymer electrolytes (GPEs) in Li-ion batteries (LIBs) is still limited. Here, a novel large-scale feasible poly(vinyl acetate) (PVAc) incorporating poly(vinylidene fluoride)-co-hexafluoropropylene (PVDF-HFP)/SiO2 membrane is prepared by a simple solution casting method. Then, the dry membrane is directly swollen by LiPF6-carbonate based electrolyte to obtain a rigid-flexible coupling GPE. The solubility of PVAc into electrolyte is greatly alleviated due to the intermolecular complexation between PVAc and PVDF-HFP. This PVAc/PVDF-HFP/SiO2 based GPE enables LiNi0.5Co0.2Mn0.3O2 (NCM523)/mesocarbon microbeads (MCMB) full cell with excellent cycling stability and rate capability. Based on conventional hot calendar “Bellcore” technology, a NCM523/MCMB pouch cell prototype using this GPE is successfully fabricated, demonstrating both excellent flexibility and high tolerance to mechanical abuse. By saving the complicated pore-regulating procedure, the design concept of rigid-flexible coupling GPE will provide new perspective on the promotion of conventional hot calendar “Bellcore” technology.

Imaging the pediatric retina: An overview.

Recent decade has seen a shift in the causes of childhood blinding diseases from anterior segment to retinal disease in both developed and developing countries. The common retinal disorders are retinopathy of prematurity and vitreoretinal infections in neonates, congenital anomalies in infants, and vascular retinopathies including type 1 diabetes, tumors, and inherited retinal diseases in children (up to 12 years). Retinal imaging helps in diagnosis, management, follow up and prognostication in all these disorders. These imaging modalities include fundus photography, fluorescein angiography, ultrasonography, retinal vascular and structural studies, and electrodiagnosis. Over the decades there has been tremendous advances both in design (compact, multifunctional, tele-consult capable) and technology (wide- and ultra-wide field and noninvasive retinal angiography). These new advances have application in most of the pediatric retinal diseases though at most times the designs of new devices have remained confined to use in adults. Poor patient cooperation and insufficient attention span in children demand careful crafting of the devices. The newer attempts of hand-held retinal diagnostic devices are welcome additions in this direction. While much has been done, there is still much to do in the coming years. One of the compelling and immediate needs is the pediatric version of optical coherence tomography angiography. These needs and demands would increase many folds in future. A sound policy could be the simultaneous development of adult and pediatric version of all ophthalmic diagnostic devices, coupled with capacity building of trained medical personnel.

AIUM Practice Parameter for the Performance of Sonohysterography and Hysterosalpingo-Contrast Sonography.

AIUM Practice Parameter for the Performance of Sonohysterography and Hysterosalpingo-Contrast Sonography.

AIUM Practice Parameter for the Performance of Ultrasound Evaluations of the Prostate (and Surrounding Structures).

AIUM Practice Parameter for the Performance of Ultrasound Evaluations of the Prostate (and Surrounding Structures).

Disinfection of Ultrasound Transducers Used for Percutaneous Procedures: Intersocietal Position Statement.

Disinfection of Ultrasound Transducers Used for Percutaneous Procedures: Intersocietal Position Statement.

The effects of gel pad thickness on the evaluation of skin structures using ultrasonography in normal dogs

Gel pads are commonly used in skin ultrasonography; however, the effects of their thickness are unknown. This study investigated the effects of pad thickness on measurements of skin thickness in 10 beagle dogs. Sonograms to measure neck skin thickness were captured without pads and using pads with thicknesses of 3, 5, 10, and 20 mm. Without pads, acoustic shading was observed due to air bubbles in the coupling gel. With 20-mm pads, echogenic artifacts were observed on the skin surface. Entry echo with 20-mm pads was significantly higher than with 3-mm pads. This suggests that visibility of the skin structure could be affected when a gel pad is not used or when a thick gel pad is selected.

Directional Ultrasound Source for Solid Materials Inspection: Diffraction Management in a Metallic Phononic Crystal.

In this work, we numerically investigate the diffraction management of longitudinal elastic waves propagating in a two-dimensional metallic phononic crystal. We demonstrate that this structure acts as an “ultrasonic lens”, providing self-collimation or focusing effect at a certain distance from the crystal output. We implement this directional propagation in the design of a coupling device capable to control the directivity or focusing of ultrasonic waves propagation inside a target object. These effects are robust over a broad frequency band and are preserved in the propagation through a coupling gel between the “ultrasonic lens” and the solid target. These results may find interesting industrial and medical applications, where the localization of the ultrasonic waves may be required at certain positions embedded in the object under study. An application example for non-destructive testing with improved results, after using the ultrasonic lens, is discussed as a proof of concept for the novelty and applicability of our numerical simulation study.

A new approach in improving granular cold water swelling starch properties using xanthan gum and β-lactoglobulin/xanthan gum electrostatic coupled gel

Granular cold water swelling (GCWS) starches are capable of creating cold-set gels without any heat treatment. However, similar to their thermally gelatinized counterparts, there are some techno-functional challenges related to these physically modified starches. The main objective of this study was to investigate the probable improvement of physical and mucoadhesive properties of alcoholic-alkaline modified GCWS tapioca and corn starches (GCWSTS and GCWSCS, respectively) in the presence of xanthan gum (XG) or β-lactoglobulin-XG electrostatic coupled gel (βlg-XG ECG). Results showed that the viscosity, consistency, pseudo-plasticity, structure recovery, and cold storage stability were improved, and the turbidity development and susceptibility against temperature rise and successive freeze-thaw cycles decreased by increasing the XG to starch ratio from 1:99 to 10:90 in the XG/GCWSTS mixtures, and from 5:95 to 10:90 in XG/GCWSCS mixtures, compared to the respective GCWS starches. The XG to starch ratios of 1:99 and 2.5:97.5 negatively influenced the characteristics of GCWSCS, except for its mucoadhesion. The maximum work of adhesion was obtained at XG to TS ratio of 5:95. Partial substitution of the starch with βlg-XG ECG increased shear-thinning behavior, percent recovery, and work of adhesion, although to a lower degree compared with XG. In contrast, the ECG could substantially reduce the long-term retrogradation and after-five-cycles freeze-thaw syneresis of the GCWS starches much more than XG, despite having a lower concentration. The results of this study suggested that the XG and βlg-XG ECG are capable of extending the applications of GCWS starches in the heat-sensitive functional formulations and 3D printable foods.

In vivo experimental study of acute intraocular hypertension in rabbit based on particle image velocimetry technique

At present, there are few in vivo experimental studies on anterior chamber flow field, and the relevant technologies are not mature. This study explores the experimental method and key techniques of particle image velocimetry (PIV) for the in vivo measurement of anterior chamber flow field with slow flow velocity in the rabbit with acute intraocular hypertension. The experimental process can be divided into three parts: model construction of rabbit eye with acute intraocular hypertension, in vivo eyeball preparation, and PIV setup. The following key techniques were mainly investigated: the optimal injection strategy of fluorescent particles and the correction strategy for image acquisition errors caused by the effects of image refraction and respiration. The results showed that the best injection method was that 15 μL of fluorescent particles solution was slowly injected into the anterior chamber through the lower part of iris and then the rabbit was released and waited for 13 h. In this way particles were completely distributed in the anterior chamber with the help of the aqueous humor circulation, and then in vivo PIV experiment could be performed. The eyeball should be covered with a square flume filled with ultrasonic coupling gel for the sake of imaging during the experiment. The Maximal Information Coefficient algorithm could be applied to correct the measured results before post-processing calculation. The results indicated that feasible injection strategy of fluorescent particles and the correction strategy for image acquisition are critical to obtain nice experiment effects for the in vivo PIV measurement of anterior chamber flow field in the rabbit with acute intraocular hypertension.

Society for Maternal-Fetal Medicine Special Statement: Reducing the risk of transmitting infection by transvaginal ultrasound examination

Recent surveys have shown widespread lapses in the procedures used to reduce the risk of transmitting infection via medical devices. Transvaginal ultrasound examination has the potential to transmit vaginal infections, including human papillomavirus. Areas of particular concern are the use of probe covers with high rates of leakage, disinfectants that are not effective against human papillomavirus, and coupling gel from multiple-use containers. We reviewed these issues, and we recommend 4 steps to reduce the risk of transmitting infection. First, during every transvaginal ultrasound exam, the probe should be covered with a sterile, single-use "viral barrier" cover or a condom. Second, sterile, single-use ultrasound gel packets should be used. Third, after every examination, the probe should be cleaned to remove any visible gel or debris. Finally, after cleaning, the probe should undergo high-level disinfection using an agent with proven efficacy against the human papillomavirus, including hydrogen peroxide, hypochlorite, or peracetic acid. Glutaraldehyde, orthophthalaldehyde, phenols, and isopropyl alcohol have virtually no efficacy against the human papillomavirus.

Incorporating chemical acids to react with bio-oil: Hydrophobicity improvement and effect on the moisture susceptibility of bio-binder

Using bio-oil to replace petroleum-based asphalt binder in pavement construction can minimize the demand for crude oil, but different sourced bio-oil may have a different effect on the asphalt binder’s properties, especially on the moisture damage resistance of pavement. Our previous research found that bio-oil from corn can increase moisture susceptibly of the asphalt binders, so this paper studies the variance of binder’s moisture susceptibly due to the addition of bio-oil and chemical modification of bio-oil to improve its hydrophobicity. Chemical characterization by elemental analysis, SARA analysis, Fourier transform infrared (FTIR) spectroscopy, and gas chromatography-mass spectrometer (GC-MS) indicated that elements and fractions distribution of bio-oil vary greatly from that of petroleum-based asphalt, and the small-molecule alcohols in bio-oil was a primary cause of bio-binder’s moisture damage resistance degradation. Moisture damage resistance validation of bin-binder at the mixture level showed that chemical modification incorporating one of the proposed chemical acids, phthalic anhydride with the dosage of 15% wt., can increase the moisture damage resistance index of residual Marshall stability (MS0) from 35.3% to 83.3%, and the tensile strength ratio (TSR) from 42.8% to 79.5%, which could meet pavement service specifications. Mechanism investigation of bio-oil’s chemical modification coupling gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) showed that the chemical modification proposed in this study improved bio-oil’s average molecular formulas from C14H35O18N0.1 to C32H56O6.3 N0.5, which was closer to that of base asphalt of C56H83O0.3 N0.5S0.2.