scholarly journals High-frequency High-resolution Echocardiography: First Evidence on Non-invasive Repeated Measure of Myocardial Strain, Contractility, and Mitral Regurgitation in the Ischemia-reperfused Murine Heart

10.3791/1781 ◽  
2010 ◽  
Author(s):  
Surya C. Gnyawali ◽  
Sashwati Roy ◽  
Jason Driggs ◽  
Savita Khanna ◽  
Thomas Ryan ◽  
...  
Keyword(s):  
High Resolution ◽  
Mitral Regurgitation ◽  
High Frequency ◽  
Myocardial Strain ◽  
Repeated Measure ◽  
Non Invasive

scholarly journals High resolution ultrasound imaging for repeated measure of wound tissue morphometry, biomechanics and hemodynamics under fetal, adult and diabetic conditions

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0241831
Author(s):  
Surya C. Gnyawali ◽  
Mithun Sinha ◽  
Mohamed S. El Masry ◽  
Brian Wulff ◽  
Subhadip Ghatak ◽  
...  
Keyword(s):  
Wound Healing ◽  
High Resolution ◽  
Ultrasound Imaging ◽  
High Frequency ◽  
Normal Skin ◽  
Repeated Measure ◽  
Non Invasive ◽  
Severe Strain ◽  
Inflammatory Phase ◽  
Wound Tissue

Non-invasive, repeated interrogation of the same wound is necessary to understand the tissue repair continuum. In this work, we sought to test the significance of non-invasive high-frequency high-resolution ultrasound technology for such interrogation. High-frequency high-resolution ultrasound imaging was employed to investigate wound healing under fetal and adult conditions. Quantitative tissue cellularity and elastic strain was obtained for visualization of unresolved inflammation using Vevo strain software. Hemodynamic properties of the blood flow in the artery supplying the wound-site were studied using color Doppler flow imaging. Non-invasive monitoring of fetal and adult wound healing provided unprecedented biomechanical and functional insight. Fetal wounds showed highly accelerated closure with transient perturbation of wound tissue cellularity. Fetal hemodynamics was unique in that sharp fall in arterial pulse pressure (APP) which was rapidly restored within 48h post-wounding. In adults, APP transiently increased post-wounding before returning to the pre-wounding levels by d10 post-wounding. The pattern of change in the elasticity of wound-edge tissue of diabetics was strikingly different. Severe strain acquired during the early inflammatory phase persisted with a slower recovery of elasticity compared to that of the non-diabetic group. Wound bed of adult diabetic mice (db/db) showed persistent hypercellularity compared to littermate controls (db/+) indicative of prolonged inflammation. Normal skin strain of db/+ and db/db were asynchronous. In db/db, severe strain acquired during the early inflammatory phase persisted with a slower recovery of elasticity compared to that of non-diabetics. This study showcases a versatile clinically relevant imaging platform suitable for real-time analyses of functional wound healing.

Non-invasive high-resolution acoustic microscopy technique using embedded nanostructures

2007 ◽  
Vol 1019 ◽  
Author(s):  
Daniel Wulin ◽  
Shriram Ramanathan
Keyword(s):  
High Resolution ◽  
Acoustic Waves ◽  
High Frequency ◽  
Acoustic Microscopy ◽  
Biological Applications ◽  
Acoustic Oscillations ◽  
Non Invasive ◽  
Microscopy Technique ◽  
First Time

AbstractAn opto-acoustic system capable of operating at frequencies greater than 1 GHz with novel biological applications is proposed for the first time. Metallic spheres with radii on the order of hundreds of nanometers dispersed inside a bio-matrix can be used to generate in-situ ultra-high frequency acoustic waves whose normal mode frequencies can be calculated using Lamb's theory for acoustic oscillations of elastic spheres. The frequency and amplitude of the resulting acoustic waves can be related to the physical properties of the metallic spheres and the surrounding bio-matrix: the acoustic waves produced by the metallic spheres are well-suited to high resolution acoustic imaging. We anticipate that our approach will open up new nanoscale techniques to study cells non-invasively.

scholarly journals Non-invasive high-frequency oscillatory ventilation in preterm infants after extubation: a randomized, controlled trial

2021 ◽  
Vol 49 (2) ◽  
pp. 030006052098491
Author(s):  
Yan Li ◽  
Qiufen Wei ◽  
Dan Zhao ◽  
Yan Mo ◽  
Liping Yao ◽  
...  
Keyword(s):  
Randomized Controlled Trial ◽  
Preterm Infants ◽  
High Frequency ◽  
Controlled Trial ◽  
High Frequency Oscillatory Ventilation ◽  
Positive Pressure ◽  
Non Invasive ◽  
Randomized Controlled ◽  
Oscillatory Ventilation ◽  
High Frequency Oscillatory

Objective To investigate the effectiveness and safety of non-invasive high-frequency oscillatory ventilation (NHFOV) in post-extubation preterm infants. Methods This was a randomized, controlled trial. A total of 149 preterm infants aged between 25 to 34 weeks’ gestational age with a birth weight of <1500 g who required invasive mechanical ventilation on admission were included. After extubation, they were randomized to the NHFOV group (n = 47), nasal intermittent positive pressure ventilation (NIPPV) group (n = 51), or nasal continuous positive airway pressure (NCPAP) group (n = 51). We compared the effectiveness and safety among these three groups. Results A total of 139 preterm infants finally completed the study. The reintubation rate was significantly lower in the NHFOV group than in the other groups. The duration of non-invasive ventilation and the length of hospital stay in the NHFOV and NIPPV groups were significantly shorter than those in the NCPAP group. The incidence of bronchopulmonary dysplasia in the NHFOV and NIPPV groups was significantly lower than that in the NCPAP group. The NHFOV group had significantly less nasal injury than the NCPAP group. Conclusion As post-extubation respiratory support in preterm infants, NHFOV has a lower reintubation rate compared with NCPAP and NIPPV, without increasing the rate of complications.

scholarly journals Predictive values of multiple non-invasive markers for myocardial fibrosis in hypertrophic cardiomyopathy patients with preserved ejection fraction

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yumin Li ◽  
Jia Liu ◽  
Yukun Cao ◽  
Xiaoyu Han ◽  
Guozhu Shao ◽  
...  
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Ejection Fraction ◽  
Myocardial Fibrosis ◽  
Troponin I ◽  
Myocardial Strain ◽  
Left Ventricular ◽  
Preserved Ejection Fraction ◽  
Predictive Values ◽  
Non Invasive ◽  
Potential Biomarker

AbstractMyocardial fibrosis assessed by late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) is associated with cardiovascular outcomes in hypertrophic cardiomyopathy (HCM) patients, but little is known about the utility of non-invasive markers for detecting LGE. This study aims to explore the association between cardiac-specific biomarkers, CMR myocardial strain, left ventricular (LV) hypertrophy and LGE in HCM patients with preserved ejection fraction (EF) and investigate the predictive values of these indexes for LGE. We recruited 33 healthy volunteers and 86 HCM patients with preserved EF to undergo contrast-enhanced CMR examinations. In total, 48 of 86 HCM patients had the presence of LGE. The LGE-positive patients had significant higher serum high-sensitivity cardiac troponin I (hs-cTnI) and N-terminal pro b-type natriuretic peptide (Nt-proBNP) levels and lower global longitudinal (GLS) and circumferential (GCS) strains than the LGE-negative group. The LGE% was independently associated with the Nt-proBNP levels, GCS, LV end-diastolic maximum wall thickness (MWT) and beta-blocker treatment. In the receiver operating characteristic curve analysis, the combined parameters of Nt-proBNP ≥ 108.00 pg/mL and MWT ≥ 17.30 mm had good diagnostic performance for LGE, with a specificity of 81.25% and sensitivity of 70.00%. These data indicate that serum Nt-proBNP is a potential biomarker associated with LGE% and, combined with MWT, were useful for identifying myocardial fibrosis in HCM patients with preserved EF. Additionally, LV GCS may be a more sensitive indicator for reflecting the presence of myocardial fibrosis than GLS.

scholarly journals PCDRN: Progressive Cascade Deep Residual Network for Pansharpening

2020 ◽  
Vol 12 (4) ◽  
pp. 676 ◽  
Author(s):  
Yong Yang ◽  
Wei Tu ◽  
Shuying Huang ◽  
Hangyuan Lu
Keyword(s):  
High Resolution ◽  
Loss Function ◽  
High Frequency ◽  
Experimental Results ◽  
Superior Performance ◽  
Residual Network ◽  
High Quality ◽  
Convolution Approach ◽  
Visual Assessments ◽  
Coarse To Fine

Pansharpening is the process of fusing a low-resolution multispectral (LRMS) image with a high-resolution panchromatic (PAN) image. In the process of pansharpening, the LRMS image is often directly upsampled by a scale of 4, which may result in the loss of high-frequency details in the fused high-resolution multispectral (HRMS) image. To solve this problem, we put forward a novel progressive cascade deep residual network (PCDRN) with two residual subnetworks for pansharpening. The network adjusts the size of an MS image to the size of a PAN image twice and gradually fuses the LRMS image with the PAN image in a coarse-to-fine manner. To prevent an overly-smooth phenomenon and achieve high-quality fusion results, a multitask loss function is defined to train our network. Furthermore, to eliminate checkerboard artifacts in the fusion results, we employ a resize-convolution approach instead of transposed convolution for upsampling LRMS images. Experimental results on the Pléiades and WorldView-3 datasets prove that PCDRN exhibits superior performance compared to other popular pansharpening methods in terms of quantitative and visual assessments.

scholarly journals Miniaturized high frequency phased array devices for high resolution neonatal and intraoperative imaging

1990 ◽  
Vol 15 (2) ◽  
pp. A10 ◽  
Author(s):  
David J. Sahn ◽  
Diana Tasker ◽  
Sandra Hagen-Ansert ◽  
Axel Brisken ◽  
Scott Corbett
Keyword(s):  
High Resolution ◽  
High Frequency ◽  
Phased Array ◽  
Intraoperative Imaging

Increased high-frequency heart rate variability during insulin-induced hypoglycaemia in healthy humans

2004 ◽  
Vol 106 (6) ◽  
pp. 583-588 ◽  
Author(s):  
Hartmut SCHÄCHINGER ◽  
Johannes PORT ◽  
Stuart BRODY ◽  
Lilly LINDER ◽  
Frank H. WILHELM ◽  
...  
Keyword(s):  
Heart Rate ◽  
High Frequency ◽  
Concomitant Increase ◽  
Plasma Adrenaline ◽  
Non Invasive ◽  
Hyperinsulinaemic Clamp ◽  
Healthy Humans ◽  
Plasma Insulin Levels ◽  
Single Blind ◽  
Cardiac Autonomic Activity

Despite causing sympathetic activation, prolonged hypoglycaemia produces little change in HR (heart rate) in healthy young adults. One explanation could be concurrent parasympathetic activation, resulting in unchanged net effects of autonomic influences. In the present study, hypoglycaemic (2.7 mmol/l) and normoglycaemic (4.7 mmol/l) hyperinsulinaemic clamp studies were performed after normoglycaemic baseline clamp periods with 15 healthy volunteers (seven male; mean age, 27 years) on two occasions in a randomized single-blind cross-over design. Non-invasive indices of cardiac autonomic activity and hormones were measured at baseline and 1 h after the beginning of hypoglycaemia or control normoglycaemia. Plasma insulin levels and mean HR were similar during both conditions. During hypoglycaemia, there was a 485% increase in plasma adrenaline (epinephrine). A shortening of the pre-ejection period by 45% suggested strong sympathetic cardiac activation. High-frequency (0.15–0.45 Hz) HRV (HR variability) increased, indicating a concomitant increase in parasympathetic tone. Thus, during hypoglycaemia-induced sympathetic cardiac activation in healthy adults, parasympathetic mechanisms are involved in stabilizing mean HR.

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