Blar i NTNU Open på forfatter "Torp, Hans"
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Cerebral Hemodynamics in Normal Neonates During Tilt: Computer Modelling and Experiments
Jarmund, Anders Hagen (Master thesis, 2019)Nyfødte barn er sårbare for å få forstyrret blodstrømmen i hjernen. I verste fall kan forstyrrelsen føre til hjerneskader og ende med død eller livsvarige funksjonsnedsettelser. Et ultralyd-system kalt NeoDoppler har nylig ... -
Clutter Filter Wave Imaging
Salles, Sebastien; Løvstakken, Lasse; Aase, Svein Arne; Bjåstad, Tore Grüner; Torp, Hans (Journal article; Peer reviewed, 2019)The elastic properties of human tissue can be evaluated through the study of mechanical wave propagation captured using high frame rate ultrasound imaging. Methods such as block-matching or phase-based motion estimation ... -
Coded Excitation in Color Flow Imaging
Holje, Jostein (Master thesis, 2007) -
Combined 2-D Vector imaging and Tracking Doppler for improved vascular blood velocity quantification
Avdal, Jørgen; Løvstakken, Lasse; Torp, Hans; Ekroll, Ingvild Kinn (Journal article; Peer reviewed, 2017)Measurement of the maximum blood flow velocity is the primary means for determining the degree of carotid stenosis using ultrasound. The current standard for estimating the maximum velocity is Pulsed Wave (PW) Doppler with ... -
Combining Automatic Angle Correction and 3-D Tracking Doppler for the Assessment of Aortic Stenosis Severity
Fiorentini, Stefano; Espeland, Torvald; Berg, Erik Andreas Rye; Aakhus, Svend; Torp, Hans; Avdal, Jørgen (Journal article; Peer reviewed, 2019)Aortic valve stenosis (AS) is a narrowing of the aortic valve opening, which causes increased load on the left ventricle. Untreated, this condition can eventually lead to heart failure and death. According to current ... -
Correlation Between Fetal Weight Gain and Birth Weight with Blood Flow in the Uterine Arteries Calculated with the PixelFlux Technique
Arneberg, Helene Caroline; Andersen, Thea Anette; Lorås, Liv; Torp, Hans; Scholbach, Thomas; Eggebø, Torbjørn Moe (Journal article; Peer reviewed, 2018)Introduction The aim was to investigate correlations between fetal weight gain/day and birthweight with blood flow estimates in the uterine arteries calculated with the PixelFlux technique and with measurements from TAmax. ... -
Data Adaptive 2-D Tracking Doppler for High-Resolution Spectral Estimation
Karabiyik, Yücel; Avdal, Jørgen; Ekroll, Ingvild Kinn; Fiorentini, Stefano; Torp, Hans; Løvstakken, Lasse (Peer reviewed; Journal article, 2019)Spectral broadening in pulsed-wave Doppler caused by the transit-time effect deteriorates the frequency resolution and may cause overestimation of maximum velocities in high-velocity blood flow regions and for large ... -
Design, Fabrication and Testing Highly Sensitive Single Element Doppler Transducers
Bolstad, Per Kristian; Hoff, Lars; Torp, Hans; Johansen, Tonni Franke (Journal article; Peer reviewed, 2018)Three common piezoelectric materials have been studied for use in pulsed wave Doppler ultrasound, where high sensitivity is required, while bandwidth is less important. A large transducer aperture, 80 mm 2 , results in a ... -
Detection of Cerebral High-Intensity Transient Signals by NeoDoppler during Cardiac Catheterization and Cardiac Surgery in Infants
Leth-Olsen, Martin; Døhlen, Gaute; Torp, Hans; Nyrnes, Siri Ann (Peer reviewed; Journal article, 2022)There is a risk of gaseous and solid micro-embolus formation during transcatheter cardiac interventions and surgery in children with congenital heart disease (CHD). Our aim was to study the burden of high-intensity transient ... -
Deteksjon av luftembolier i hjernen hos nyfødte ved hjelp av ultralyd Doppler
Kjelsaas, Karoline (Master thesis, 2020)Når spedbarn er født med en form for hjertefeil kan kateterintervensjon eller hjerte-kirurgi hjelpe. Dette kan føre til at luftbobler, eller embolier, kommer inn i blodstrømmen. Årsaken er for det meste ukjent, men ... -
Earlybird: A new approach to vascular assessment
Pettersen, Erik Mulder (Doctoral theses at NTNU, 2022:81, Doctoral thesis, 2022)The aim of the thesis was to explore and identify possible clinical applications within vascular health for a novel, high-sensitivity, ultrasound Doppler system (earlybird). The unit was developed by Professor Hans Torp, ... -
The Effect of 12-Week Treatment with Intermittent Negative Pressure on Blood Flow Velocity and Flowmotion, Measured with a Novel Doppler Device (Earlybird). Secondary Outcomes from a Randomized Sham-Controlled Trial in Patients with Peripheral Arterial Disease
Pettersen, Erik Mulder; Hoel, Henrik; Torp, Hans; Hisdal, Jonny; Seternes, Arne (Peer reviewed; Journal article, 2022)Background Treatment with intermittent negative pressure (INP) is proposed as an adjunct to standard care in patients with peripheral arterial disease (PAD). The aims of this study were to evaluate the applicability of a ... -
Effects of tilt on cerebral hemodynamics measured by NeoDoppler in healthy neonates
Jarmund, Anders Hagen; Ødegård, Siv Steinsmo; Torp, Hans; Nyrnes, Siri Ann (Peer reviewed; Journal article, 2021)Background: Today, there are conflicting descriptions of how neonates respond to tilt. Examining physiologic responses of cerebral blood flow velocities (BFVs) in challenging situations like a tilt requires equipment that ... -
The Generalized Contrast-to-Noise Ratio: A Formal Definition for Lesion Detectability
Molares, Alfonso Rodrígues; Rindal, Ole Marius Hoel; D´Hooge, Jan; Måsøy, Svein-Erik; Austeng, Andreas; Bell, Muyinatu A. Lediju; Torp, Hans (Peer reviewed; Journal article, 2020)In the last 30 years, the contrast-to-noise ratio (CNR) has been used to estimate the contrast and lesion detectability in ultrasound images. Recent studies have shown that the CNR cannot be used with modern beamformers, ... -
Hands-free continuous carotid Doppler ultrasound for detection of the pulse during cardiac arrest in a porcine model
Faldaas, Bjørn Ove; Nielsen, Erik Waage; Storm, Benjamin; Lappegård, Knut Tore; How, Ole-Jakob; Nilsen, Bent Aksel; Kiss, Gabriel Hanssen; Skogvoll, Eirik; Torp, Hans; Ingul, Charlotte Ingeborg Björk (Peer reviewed; Journal article, 2023)Background/Purpose Pulse palpation is an unreliable method for diagnosing cardiac arrest. To address this limitation, continuous hemodynamic monitoring may be a viable solution. Therefore, we developed a novel, hands-free ... -
Hurtig simulering av ultralydavbildning av flater i 3D: Ved hjelp av Fouriertransformen
Galtrud, Bernt Garten (Master thesis, 2009)Denne rapporten presenter en ny og egenutviklet metode for å simulere ultralydavbildning av flater i rommet. Metoden bygger på, og er laget med tanke på bruk sammen med, ultralydsimulatoren FUSK som er utviklet av Torbjørn ... -
In Vitro Setup for Coronary Circulation with Ventricular Motion
Garcia Mayuri, Alyssa Ninoska (Master thesis, 2017)Blood and tissue motion can be detected using Doppler ultrasound. However, in a complex system such as the human body, the blood is not the only matter in motion. Doppler signals reflected by blood are often disturbed by ... -
Instant Detection of Cerebral Blood Flow Changes in Infants with Congenital Heart Disease during Transcatheter Interventions
Leth-Olsen, Martin; Døhlen, Gaute; Torp, Hans; Nyrnes, Siri Ann (Journal article; Peer reviewed, 2024)Background: Transcatheter interventions are increasingly used in children with congenital heart disease. However, these interventions can affect cardiac output and cerebral circulation. In this pilot study, we aimed to ... -
Intraoperative Ultrasound Strain Imaging of Brain Tumors
Børstad, Thomas Kristoffersen (Master thesis, 2011)Intraoperative ultrasound strain imaging of the brain visualizes brain tissue deformation as an image. The hypothesis is that strain and elastographic values can be used to complement conventional B-mode image in the task ... -
Low frequency cerebral arterial and venous flow oscillations in healthy neonates measured by NeoDoppler
Ødegård, Siv Steinsmo; Torp, Hans; Follestad, Turid; Leth-Olsen, Martin; Støen, Ragnhild; Nyrnes, Siri Ann (Peer reviewed; Journal article, 2022)Background: A cerebroprotective effect of low frequency oscillations (LFO) in cerebral blood flow (CBF) has been suggested in adults, but its significance in neonates is not known. This observational study evaluates normal ...