bluuebunny/crossref_metadata_2025_split huggingface dataset:
An integrated multichannel system for air-coupled CMUT array imaging and guided wave detection applications
Authors: Wang Junjie , Li Shaojie , Zhang Hui , Wang Zhuochen 
Published: October 2024

Abstract
Capacitive micromachined ultrasonic transducers (CMUTs) made by MEMS process have become a new choice for air-coupled ultrasonic transducers due to their high sensitivity, low acoustic impedance and easy arraying. At present, in the air coupling application of CMUT transducer, due to the weak signal strength of single element, the CMUT array usually works in a whole piece, limiting the advantage of the array. Therefore, a multi-channel air-coupled CMUT imaging system with high-voltage DC bias and low-noise high-gain current signal amplification is designed to realize the electronic scanning of our CMUT arrays. The imaging system has 16 transmit and receive channels, and each channel consists of pulse transmitting circuit, AC/DC coupling circuit, impedance matching circuit, low-noise transimpedance amplification circuit, controllable gain amplification circuit and AD circuit. The imaging chain and element control method of our CMUT array were developed to realize the electronic scanning imaging of air-coupled ultrasound. The feasibility of the system for non-destructive testing was also verified via the Lamb wave detection in a metal plate.…
A High Q Lamb Wave Resonator with Dummy Toes Based on 20% ScAlN Film
Authors: Yang Sijie , Liu Wenjuan , Wen Zhiwei , Cai Yao , Liu Yan , Sun Chengliang 
Published: October 2024

Abstract
The lamb wave resonator (LWR) based on aluminum nitride (AlN) films are preferred strategy for high-frequency filters in 5G communication due to the tunable electromechanical coupling and high Q value. However, since the low electromechanical coupling and piezoelectric coefficient of AlN films, conventional lamb filters are difficult to meet the requirements of high bandwidth and low loss. This work proposes a lamb wave resonator with dummy toes (DT-LWR) based on scandium-doped aluminum nitride (ScAlN) film to improve the quality factor(Q) meanwhile suppress the spurious modes. The processed DT-LWR was tested using a vector network analyser (VNA, Keysight N5222B), and the MBVD model was used to fit the Z parameters. The Q value of DT-LWR is 1437.23, while that of LWR is 1250.09. It is increased by 14.97%. The enhancements make the DT-IWR as an ideal for filters with minimal insertion loss.
Writing and Work
Authors: Rembis Michael 
Published: October 2024

Abstract
In a nineteenth-century world where madness was social and biological, open and fluid, and rooted in relationships, work played a central role in mad people’s lives and in the writing of former asylum inmates. The state, physicians, journalists, and mad writers considered the ability to perform certain forms of gendered labor a powerful measure of madness, and each offered different, often competing, perspectives on the relationship between madness and work. Mad writing was also a form of work that, to date, has not been explored by historians. Both women and men had to secure the resources, cultivate the relationships, and make the time necessary to write. For women, who faced limited social and economic options after asylum commitment, writing and speaking in public could be their only form of work.
Navigating dementia feeding decisions in Asia: a mixed methods study of caregivers
Authors: Andres Ellie B , Chaudhry Isha , Balasubramanian Ishwarya , Poco Louisa , Yap Philip , Malhotra Chetna ,   PISCES study group, Seow Dennis , Tan Lay Ling , Tham Weng Yew , Vaingankar Janhavi , Foo Jason , Tan Boon Yeow , Tong Kamun , Ng Wai Chong , Allen John Carson , Malhotra Rahul , Wee Weng Mooi Tan Shiou Liang , Ng Li Ling , Goveas Richard , Mok Vanessa , Sim Alisson , Ng Wei Fern , Wong Hon Khuan , Balasundaram Bharathi , Tan Rui Qi , Ong Pui Sim , Cheong Chin Yee , Yee Alethea , Pheng Chung , Tiong Christina , Hum Allyn , Lee Angel , Finkelstein Eric A 
Published: October 2024

Abstract

Background
Tube feeding is discouraged among older adults with advanced dementia; nevertheless, caregivers often find feeding decisions challenging to navigate.

Aim
This study aims to gain a comprehensive understanding of tube feeding among community-dwelling older adults with advanced dementia in Singapore and its relationship to older adult quality of life (QoL) and caregiver psychological distress.

Methods
We use a convergent mixed-methods design, synthesising analysis of qualitative caregiver interviews (n = 25) and two-year prospective, longitudinal cohort survey data (n = 215, 1018 observations).

Results
Findings from the qualitative interviews revealed caregivers’ expectations of reduced QoL for older adults with feeding tubes and their own distress related to making feeding decisions and fears prompting plans to tube-feed. Sixteen percent of community-dwelling older adults with advanced dementia relied on feeding tubes during the two-year study period. Adjusting for potential confounding and using instrumental variables estimation, tube feeding was associated with reduced older adult QoL (P &lt; .05) and increased caregiver anxiety and depression (P &lt; .10).

Conclusion
Consistent with expert guidelines, we found that tube feeding was associated with significantly reduced QOL among older adults living with dementia and increased distress among caregivers relative to those of older adults without feeding tubes. Despite caregivers’ recognition of reduced QOL associated with older adult use of feeding tubes, many expressed angst related to feeding choices. Our findings suggest the need for decision tools to support caregivers in making informed decisions concordant with their values.
Global longitudinal strain measurement in the modern era - is artificial intelligence the answer ?
Authors: Botan R , Winkler A , Dindane Z , Alothman G , Sveric K , Linke A 
Published: October 2024

Abstract

Background
Global longitudinal strain (GLS) enhances the assessment of left ventricular (LV) function beyond ejection fraction (EF) in 2D echocardiography (Echo). However, manual GLS measurement, the most common technique, is operator dependent. A novel vendor-independent artificial intelligence (AI)-based software streamlines automated 2D-Echo exam evaluation and GLS calculation.

Purpose
We sought to evaluate the ability of the AI to automatically identify LV 4-, 2-, and 3-chamber views (CV) from 2D-Echo exams and to validate GLS against the conventional manual method.

Methods
540 patients underwent standard 2D-Echo exams. The server-based AI recognized the optimal LV CVs from 2D-Echo exams and automatically calculated triplane GLS by endocardial delineation (n=489, 91%). Manual LV GLS was performed independently by accredited cardiologists. Pearson’s correlation (R) and Bland-Altman analysis were performed to assess bias and limits of agreement (LOA) for GLS. Multivariate between-method regression was performed using ordinary least squares to disclose possible sources of possible bias. Significance was defined as a 2-tailed P value &lt; 0.05.

Results
Patients’ median age was 70 years [18-93], 59% were males. The 2D-Echo indications were coronary artery disease (36%), valvular heart disease (15%), non-ischemic heart failure (15%) and others (34%). The feasibility of the AI to calculate GLS was 91% (n=489) due to endocardial border delineation issues. AI correctly classified all CVs. An excellent correlation (r=0.92, p&lt;0.001) was observed between AI and manual GLS, with low bias (0.5%) and narrow LOAs (-3.1 and +4.2%) (Figure 1, top row). We identified LV end-diastolic volume and EF as statistically significant confounders (p &lt; 0.05) with only small effect as depicted in Figure 1 (bottom row). Neither sex, age, acoustic window, body mass index, nor heart rate, along with the interaction with sex, end-diastolic volume, or EF, were significant (p &gt; 0.23).

Conclusion
AI-based LV GLS calculation in 2D-Echo shows promising feasibility and accuracy. Strong agreement between AI-derived GLS and manual measurements supports its reliability. The AI's ability to identify optimal LV views underscores its robustness. Further validation and refinement are warranted, highlighting the transformative potential of AI in advancing cardiovascular diagnostics.
Evaluating the performance of automatic wave speed estimators of natural shear waves to assess myocardial stiffness
Authors: Araujo Andrade Sousa A , Orlowska M , Wouters L , Youssef A , Caenen A , Duchenne J , D'hooge J , Voigt J U 
Published: October 2024

Abstract

Introduction
Cardiac Shear Wave Elastography is an emerging non-invasive technique using ultrafast echocardiographic imaging. Natural shear waves (SW) occur after mitral valve closure (MVC) and aortic valve closure (AVC), and their propagation velocities are directly related to myocardial stiffness. However, the current assessment of SW velocities lacks a gold standard method, and relies on manual measurements with their inherent variability.

Purpose
To explore new automated methods for shear wave velocity estimates, aiming to achieve greater accuracy, less variability, and high feasibility.

Methods
To visualize shear waves, anatomical M-modes were drawn (4±1 cm) along ventricular septum in parasternal long axis views (PLAX), acquired with high-frame-rate echocardiography (1055±159 Hz). M-modes were colour coded for tissue acceleration. SWs appear as tilted green bands after MVC & AVC, the slope of which represents the SW propagation velocity. One hundred-twenty different slopes from healthy volunteers (n=67) and patients (n=53) were measured manually and with 9 different automatic methods. All automatic methods were initiated by indicating the approximate position of the shear wave in the M-mode with a mouse click of the user. Measurements were repeated three times to assess measurement reproducibility. (figure 1, A). In order to determine the influence of display settings, three different acceleration colour scales were tested (0.5, 1, 2 m/s²). (Figure 1, B). Failure of correctly identifying shear waves was counted to assess feasibility. Due to the lack of a gold standard, manual measurements of an experienced reader served as reference.

Results
Three of nine automatic methods: Radon Transformation (RT), Regression Segmentation Maximum value (RM), Regression Segmentation Weighted Maximum (RMW), revealed the least variability with repeated measurements (0.0±0.0 m/s for all) and colour scales (0.0±0.0, 0.1±0.2 and 0.1±0.2 m/s, resp.). Those three methods showed moderate to good agreement (r=0.66, ICC 0.77 [CI 0.64- 0.85]; r= 0.67, ICC 0.75 [CI 0.50 -0.86]; and r= 0.77, ICC 0.85 [CI 0.73-0.90], resp.) with manual measurements (r=0.96, ICC 0.98 [CI 0.97- 0.99] (figure 2).

Conclusion
RT, RM, and RMW showed a good reproducibility while RMW showed the best agreement with manual measurements. Our data suggest, that the RMW method could offer an objective alternative for SW velocity estimations. Further research is needed to explore their applicability in clinical scenarios.
Usefulness of left ventricular mechanical dyssynchrony for predicting atrial fibrillation and adverse outcomes following first atrial fibrillation event
Authors: Alhakak A , Skaarup K G , Lassen M C H , Johansen N D , Jensen G B , Schnohr P , Mogelvang R , Biering-Sorensen T 
Published: October 2024

Abstract

Background
Left ventricular mechanical dyssynchrony (LVMD) has shown to predict many cardiovascular outcomes including ventricular arrhythmias. Our hypothesis is that LVMD can reveal early atrial dysfunction.

Purpose
The aim of this study was to investigate whether LVMD can be used to predict atrial fibrillation (AF) and adverse outcomes following first AF event in individuals from the general population.

Methods
A total of 3785 individuals (mean age 55±17 years, 57% women) from the general population free of AF, heart failure (HF) and prior stroke had an echocardiographic examination performed including two-dimensional speckle tracking echocardiography. LVMD was calculated as the standard deviation of the regional time-to-peak strain from the three apical views. The primary endpoint was AF, and the secondary endpoint was complicated AF as assessed by the occurrence of either stroke or HF after the diagnosis of AF.

Results
During a median follow-up of 5 years (interquartile range, 4.4-6.2 years), 142 (4%) individuals were diagnosed with AF, and of these 22 (15%) individuals developed HF or stroke. LVMD was a univariable predictor of AF (per 10ms increase: HR 1.03; 95% CI (1.02-1.05), p&lt;0.001, Figure). The association remained significant even after multivariable adjustment for age, sex, body mass index, diabetes, hypertension, heart rate, previous ischaemic heart disease, systolic blood pressure, diastolic blood pressure, smoking, left ventricular ejection fraction, global longitudinal strain, left atrial volume index (LAVI), and E/e’ (per 10ms increase: HR 1.02; 95% CI (1.00-1.04), p=0.042). LVMD also predicted complicated AF, and the association remained significant even after multivariable adjustment (per 10ms increase: HR 1.05; 95% CI (1.01-1.09), p=0.026).
Furthermore, LVMD provided incremental prognostic information over the LAVI with regard to predicting AF (Harrell’s C-statistics 0.66 vs. 0.70, p=0.012).

Conclusion
In a low-risk general population, LVMD provides prognostic information on the risk of AF. Additionally, LVMD can identify individuals with complicated AF defined as occurrence of either stroke or HF following the diagnosis of incident AF. Furthermore, LVMD provides incremental prognostic information over the LAVI in predicting AF.
Left atrial strain demonstrates the ability to distinguish patients with pre and post-capillary pulmonary hypertension
Authors: Bauer F , Raitiere O , Artaud Macari E , Besbes B , Si Belkacem N , Saidi N , Savale L 
Published: October 2024

Abstract

Background
The characterization of pulmonary hypertension (PH) patients into pre or postcapillary (pcPH)phenotypes poses a challenge during screening due to the ambiguity surrounding their comorbidities. This distinction is crucial as it influences treatment decisions and prognostication.

Purpose
Investigating Left Atrial Strain as a Discriminant Marker for Distinguishing Pre and Post-Capillary PH.

Methods
Out of 164 patients exhibiting both pre- and post-capillary phenotypes, 97 had optimal left atrial 2D strain. Left atrial 2D strain was performed with a GE Vivid9 ultrasound machine equipped with dedicated software, ensuring meticulous attention to image quality and region of interest thickness restricted to a maximum of 6 mm. Subsequently, the peak left atrial strain during reservoir function was quantified as part of the investigation. To determine the optimal cut-off value, ROC curve analysis was employed.

Results
60 patients had pcPH while 37 had pre-capillary PH. Mean age was 65±12y. Mean pulmonary artery pressure, wedge pressure, cardiac output and pulmonary vascular resistance averaged 40,9±10,7 mm Hg, 15,7±8,7 mm Hg, 5,9±2,0 l/min and 4,7±3,1 WU, respectively. Left atrial 2D strain ranged from +2,5% to 60%, with a mean of +18,2±11,2%. From ROC cure analysis, patients with LA 2D strain &gt; +19,1% had a precapillary phenotype with a sensitivity and a specifity of 93% and 88% respectively (Fig 1). Left atrial 2D strain demonstrates higher sensitivity compared to various parameters, such as scores from the European Society of Respiratory Disease, left ventricular end-diastolic pressure estimation from the American Society of Echocardiography, HFA-PEFF score, and H2FPEF from the AHA.

Conclusion
Left atrial 2D strain demonstrates superior sensitivity in distinguishing between patients with pre and post-capillary pulmonary hypertension compared to other assessment methods.FIG 1:Left atrial 2D strainFig 2:SENS of parameters and scores
Normal reference of myocardial work during exercise stress echocardiography and the doubt about wasted work
Authors: Wang Y , Yin L 
Published: October 2024

Abstract

Aims
Myocardial work (MW) estimated based on pressure-strain loops is a noninvasive parameter for evaluating left ventricular function. The aims of this study were (1) to characterize the MW changes at rest and post-exercise in healthy adults and heart failure with preserved ejection fraction (HFpEF) patients, (2) to explore the related influencing factors for the increase of global wasted work (GWW) after exercise.

Methods and results
The study enrolled 167 healthy adults and 38 HFpEF patients. All subjects underwent comprehensive echocardiographic assessment at rest and immediately after a symptom-limited treadmill stress test. The MW changes and the impact of sex were analyzed. The related influencing factors for the increase of GWW after exercise were explored. Global work efficiency (GWE) was decreased and other global parameters were increased after exercise in normal adults. There was no significant difference of all global parameters between sexes at rest. GWE was higher in men after exercise (p&lt;0.05).There was no significant difference in MW reserve parameters between sexes. Peak positive strain (PPS) significantly increased after exercise, while GWE reduced in normal adults and HFpEF patients (p&lt;0.05). PPS was independently associated with GWW in normal adults and patients with HFpEF both at rest and after exercise (normal adults: r: 0.77, p&lt;0.001 at rest, r: 0.72, p&lt;0.001 after exercise; HFpEF patients: r: 0.74, p&lt;0.001 at rest, r: 0.62, p&lt;0.001 after exercise).

Conclusion
Global MW parameters were less affected by sex. PPS was independently associated with GWW in normal adults and patients with HFpEF and the work done due to myocardial elongation might not be calculated as wasted work during the isovolumic contraction phase.example of myocardial work and PPSThe relationship between PPS and GWW
High altitude exercise stress echocardiograph for identification of susceptibility to acute mountain sickness
Authors: Wang Y , Xu Y , Wang S J , Yin L X 
Published: October 2024

Abstract

Background
Acute high-altitude exposure increases the risk of acute mountain disease (AMS) and high-altitude pulmonary edema. After the initial exposure to high altitude, mountain climbers are worried about whether they will develop AMS. At high altitudes, there are no accurate indicators to predict the near future occurrence of AMS.

Objectives
To investigate whether treadmill exercise stress echocardiography at high altitude can predict the occurrence of AMS, and to find out some powerful factors associated with the susceptibility to AMS.

Methods
36 healthy lowlanders were taken by bus from sea level to an altitude of 3600 m the next morning, during which they rested overnight at an altitude of 2150 m. Treadmill exercise stress echocardiography was performed immediately upon arrival at 2150 m, and the 2018 Lake Louise Questionnaire Score was performed the next day when arrived at the altitude of 3600 m. Heart rate (HR) and blood pressure (BP) were monitored during stress echocardiography. Left ventricular (LV) ejection fraction and E/e’ were calculated at rest and immediately after exercise. Other right ventricular systolic function parameters and pulmonary artery pressure (PAP) were calculated at the same time, which included tricuspid regurgitation velocity (TRV), tricuspid annular peak systolic excursion (TAPSE), systolic PAP (SPAP), right ventricular (RV) dimension by 2D, RV fraction of area change (FAC), right ventricular outflow tract velocity time integral (RVOT VTI). Pulmonary vascular resistance (PVR) was calculated according to the formula: TRV/RVOT VTI*10+0.16. Mean PAP (mPAP) was calculated as the formula: sPAP*0.61+2. All subjects ascended to 3600m within 24 hours by bus. AMS was identified by 2018 Lake Louise Questionnaire Score. Univariable and multivariable logistic regression analysis assessed independent factors associated with AMS.

Results
At the altitude of 3600m, 13 of 36 subjects had AMS, which defined as AMS (+) group. And the rest was AMS (-) group. There were no significant differences in HR, BP, SO2 and LV systolic and diastolic function between the two groups (P &gt; 0.05). No significant differences were noted at rest except for TV s' (P &lt; 0.05). Immediately after exercise, TRV, TAPSE, SPAP, mPAP, PVR, and RV area at the end of systole were much higher in AMS (+) group (all P &lt; 0.05). While FAC and TVs’/SPAP were much lower in AMS (+) group (P &lt; 0.05). By multivariable logistic regression model, mPAP immediately after exercise was significantly correlated with AMS occurrence (OR =1.332, 95% CI: 0.669-0.993, P= 003). The cutoff value of mPAP to predict AMS was 32 mmHg (AUC: 0.831, specificity: 86.7%, sensitivity: 76.9%).

Conclusions
The mPAP immediately after exercise upon arrival at an altitude of 2150 m is a strong predictor of near future AMS, and treadmill exercise stress echocardiography is a simple and non-invasive tool to help mountain climbers avoid more severe mountain sickness.
Regadenoson stress echocardiography: a road ahead
Authors: Fernandez Galindo M , Capdeville S , Abad Romero R , Nieto Becerro S , Denche C , Garcia Robles J A , Arribas Ynsaurriaga F , Solis J 
Published: October 2024

Abstract

Introduction
Drugs used in stress echocardiography (SE) have important limitations due to side effects and contraindications. Since its approval in 2008, Regadenoson has seen a significant increase in usage. This is largely attributed to its good safety profile and diagnostic accuracy, making it the preferred drug for stress tests in many European centers. However, despite its expanding use and major advantages, current guidelines don't place it as the first choice for SE, probably because the reported experience with this drug remains limited. The aim of the present study was to assess the safety and short-medium term prognosis of patients who underwent Regadenoson SE.

Methods
Retrospective observational study. Patients who underwent Regadenoson SE between 2017 and 2023 were included. Safety was assessed by monitoring immediate adverse effects following Regadenoson infusion and the need for using an antidote (Aminophylline). A positive test result was defined by the occurrence of any of the following: wall motion abnormalities, left ventricle dilatation, electrocardiographic changes or symptoms of ischemia. During the follow up, we registered the incidence of ischaemic events (admission for unstable angina, acute myocardial infarction (AMI) or cardiovascular (CV) death) and other CV events such as admission for heart failure (HF) and stroke. Additionally, we evaluated patients in both groups who underwent coronary angiography (by computerized tomography or coronary catheterization) during the follow up period. The groups with negative SE (NSE) and positive SE (PSE) were compared.

Results
The total number of patients was 344, with a median follow up of 29 months. Basal population characteristics and events by group (NSE and PSE) are shown in Figure 1. We needed to use the antidote in only one case, because of ventricular bigeminism, with no other major adverse effects reported. SE was positive in 37 (11%) patients. In this group, patients were more likely to present ischaemic events (16% vs. 3%, p&lt;0.01) and admissions for HF (24% vs. 5%, p &lt;0.01), compared to the NSE one. In those who underwent coronary angiography, revascularization was needed in 14 patients of the PSE group, and only in 7 of the NSE group (38% vs 2%, p &lt; 0.05). The indications for these last cases were persistent angina in 5 patients (2 of them with history of coronary artery disease) and revascularization following an AMI in 2 patients. (Figure 2).

Conclusions
The probability of an ischaemic event after a negative Regadenoson SE remains very low, unlike positive studies. Regadenoson SE showed to be both safe in assessing ischemic cardiomyopathy and very useful for its prognostic value. These findings encourage its expanding use in the stress echo lab.