1,074 results match your criteria: "Center for Medical Physics and Biomedical Engineering[Affiliation]"

Significance: A data-based calibration method with enhanced depolarization contrast in polarization-sensitive optical coherence tomography (PS-OCT) was developed and demonstrated effective for detecting melanin content in the eye.

Aim: We aim to mitigate the dependence between the measured depolarization metric and the intensity signal-to-noise ratio (SNR) for improved visualization of depolarizing tissues, especially in low SNR regions, and to demonstrate the enhanced depolarization contrast to evaluate melanin presence.

Approach: A function for calibrating the depolarization metric was experimentally derived from the young albino guinea pig, assuming depolarization free in the retina.

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: Patients with a HeartMate 3 (HM3) left ventricular assist device (LVAD) typically receive anticoagulation and antiplatelet therapy. The HM3 has shown a marked reduction in hemocompatibility-related adverse events (HRAEs) like stroke, bleeding, and pump thrombosis. This study evaluated whether aspirin (ASA) response influences HRAE incidence and if ASA sensitivity changes over time in HM3 recipients.

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5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PpIX) fluorescence shows high sensitivity in detecting the tumor core of high-grade gliomas (HGG) but poor sensitivity for tissue of low-grade gliomas (LGG) and the margins of HGG. The characteristic emission peak for PpIX is known to be located at 635 nm. Recently, a second emission peak was described at 620 nm wavelength in LGG and the tumor infiltration zone of HGG.

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Objectives: Radical prostatectomy (RP) is a common intervention in patients with localized prostate cancer (PCa), with nerve-sparing RP recommended to reduce adverse effects on patient quality of life. Accurate pre-operative detection of extraprostatic extension (EPE) remains challenging, often leading to the application of suboptimal treatment. The aim of this study was to enhance pre-operative EPE detection through multimodal data integration using explainable machine learning (ML).

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Mega scientific conferences increasingly suffer from the need for short and poster presentations without discussion. An alternative is to organize workshops in hotels large enough to accommodate all participants. This significantly increases the opportunities for constructive discussion during breakfasts, lunches, dinners and long evenings that can bring together experts of scientific and clinical sub-specialties and young fellows.

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Purpose: Currently, no standard for the measurement of retinal oxygen extraction exists. Here, we present a novel approach for measurement of retinal oxygen extraction based on two commercially available devices, namely laser speckle flowgraphy (LSFG) and retinal oximetry.

Methods: The study was conducted in a randomized, double-masked design.

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Source-detector trajectory optimization for FOV extension in dental CBCT imaging.

Comput Struct Biotechnol J

December 2024

Research Center for Clinical AI-Research in Omics and Medical Data Science (CAROM), Department of Medicine, Danube Private University (DPU), Krems, Austria.

Article Synopsis
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In vitro assessment of small-diameter synthetic vascular grafts usually uses standard cell culture conditions with early-passage cells. However, these conduits are mainly implanted in elderly patients and are subject to complex cellular interactions influenced by age and inflammation. Understanding these factors is central to the development of vascular grafts tailored to the specific needs of patients.

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Surface Functional Electrical Stimulation (FES) is a well-studied intervention for multiple muscular disorders. However, it is still controversially discussed as a complementary therapy for complete facial paralysis. The aim of this intervention is to test a daily home-based ES concept as a pilot study regarding safety, feasibility, and effects on facial functionality and symmetry.

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Purpose: To develop a quantitative tool for assessing the posterior ocular shape using widefield, volumetric optical coherence tomography (OCT) in eyes with myopia.

Methods: This observational, cross-sectional study included 178 eyes from 113 participants. Participants underwent a standardized eye examination, including ocular biometry and a custom ultrawide OCT.

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Functional Electrical Stimulation (FES) is an established intervention for a range of muscular and neurological disorders that has already been studied in numerous publications. However, its application to Peripheral Facial nerve Paralysis (PFP) still needs to be sufficiently investigated. As the first approach known to the authors, this study examines the effect of FES on the facial muscles in complete PFP using ultrasonography as a means of observation.

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Aside from enabling voluntary control over paralyzed muscles, a key effect of spinal cord stimulation is the alleviation of spasticity. Dysfunction of spinal inhibitory circuits is considered a major cause of spasticity. These circuits are contacted by Ia muscle spindle afferents, which are also the primary targets of transcutaneous lumbar spinal cord stimulation (TSCS).

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Bessel beam optical coherence microscopy enables multiscale assessment of cerebrovascular network morphology and function.

Light Sci Appl

November 2024

Institute of Pharmacology and Toxicology & Institute for Biomedical Engineering, Faculty of Medicine, University of Zurich, Zurich, Switzerland.

Understanding the morphology and function of large-scale cerebrovascular networks is crucial for studying brain health and disease. However, reconciling the demands for imaging on a broad scale with the precision of high-resolution volumetric microscopy has been a persistent challenge. In this study, we introduce Bessel beam optical coherence microscopy with an extended focus to capture the full cortical vascular hierarchy in mice over 1000 × 1000 × 360 μm field-of-view at capillary level resolution.

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Purpose: To study the ocular and systemic factors affecting optic nerve head (ONH) perfusion data as obtained using a commercially available laser speckle flowgraphy (LSFG) device in a cohort of Caucasian subjects without ocular diseases. Also, to assess the intrasession repeatability and intersession reproducibility of ONH, macular, retinal, and choroidal perfusion.

Methods: Seventy-five healthy eyes of 75 Caucasian participants underwent LSFG and spectral-domain optical coherence tomography (SD-OCT) on the same visit.

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Significance: Optical coherence tomography (OCT) images are prone to image artifacts due to the birefringence of the sample or the optical system when a polarized light source is used for imaging. These artifacts can lead to degraded image quality and diagnostic information.

Aim: We aim to mitigate these birefringence-related artifacts in OCT images by adding a depolarizer module in the reference arm of the interferometer.

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Background: Accurate pharmacokinetic modelling in PET necessitates measurements of an input function, which ideally is acquired non-invasively from image data. For hepatic pharmacokinetic modelling two input functions need to be considered, to account for the blood supply from the hepatic artery and portal vein. Image-derived measurements at the portal vein are challenging due to its small size and image artifacts caused by respiratory motion.

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Closing the sensory feedback loop is necessary for effective neurorehabilitation.

PLoS Biol

October 2024

Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.

Recent advances in neurotechnology enable somatosensory feedback restoration in disabled individuals. This Perspective discusses how closing the sensory feedback loop with brain implants and nerve electrodes for stimulation may improve rehabilitation and assistive systems for patients.

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Background: P-glycoprotein (P-gp) is an efflux transporter which is abundantly expressed at the blood-brain barrier (BBB) and which has been implicated in the pathophysiology of various brain diseases. The radiolabelled antiemetic drug [C]metoclopramide is a P-gp substrate for positron emission tomography (PET) imaging of P-gp function at the BBB. To assess whether [C]metoclopramide can detect increased P-gp function in the human brain, we employed drug-resistant temporal lobe epilepsy (TLE) as a model disease with a well characterised, regional P-gp up-regulation at the BBB.

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We present improvements on the adaptive optics (AO) correction method using a pyramid wavefront sensor (P-WFS) and introduce a novel approach for closed-loop focus shifting in retinal imaging. The method's efficacy is validated through adaptive optics optical coherence tomography (AO-OCT) imaging in both, healthy individuals and patients with diabetic retinopathy. In both study groups, a stable focusing on the anterior retinal layers is achieved.

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Effect of childhood atropine treatment on adult choroidal thickness using sequential deep learning-enabled segmentation.

Asia Pac J Ophthalmol (Phila)

October 2024

Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore; Duke-NUS Medical School, National University of Singapore, Singapore, Singapore. Electronic address:

Article Synopsis
  • The study aimed to measure choroidal thickness in adults who underwent childhood atropine treatment for myopia using a deep learning segmentation method.
  • It found that 77.7% of the participants received atropine, which was linked to a choroid thickness increase of 20-40 μm in specific regions of the eye, after accounting for age and sex.
  • The research also indicated a relationship between greater central choroidal thickness and a lower incidence of tessellated fundus, implying childhood atropine exposure may have lasting effects on eye structure.
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Article Synopsis
  • - A quasi-experimental study tested the effects of photobiomodulation (a type of laser therapy) on bone mineral density (BMD) in eight patients with complete spinal cord injury and osteoporosis, applying the treatment on one side of the body and using the other side as a control.
  • - The treatment involved using a specific type of laser at various energy densities based on the bone's depth from the skin and was administered three times weekly for eight weeks, with BMD and vitamin D levels measured at the start, after treatment, and weeks later.
  • - Results showed significant BMD improvements in the proximal-femur and forearm regions, along with increased vitamin D levels, although no changes were noted in other areas or
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Article Synopsis
  • - Somatosensory neuroprostheses are devices designed to restore or enhance touch and body awareness in individuals with sensory impairments from neurological issues or injuries, using electrical stimulation methods.
  • - Recent advancements have shifted focus from just developing these technologies to actual clinical studies, showing promising results in how they affect sensory perception, function, and mental well-being.
  • - The review discusses ongoing human trials, findings on the effectiveness of these systems, potential improvements for more realistic sensory experiences, and outlines challenges that still need to be overcome for wider use.
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Low-cost optical coherence tomography has recently emerged as a growing field due to the increased need for general availability of OCT devices outside of the clinics. One of the main obstacles in creating low-cost SS-OCT systems is the price of the laser. In this work, we study the influence of different tuning parameters (e.

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