Erik Harks

Eindhoven, Noord-Brabant, Nederland Contactgegevens
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All-round healthcare professional with 15+ years of experience in medical device industry…

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Publicaties

  • Characteristics of Radiofrequency Catheter Ablation Lesion Formation in Real Time In Vivo Using Near Field Ultrasound Imaging

    JACC Clin Electrophysiol . 2018 Aug;4(8):1062-1072

    Objectives: Visualizing myocardium with near field ultrasound (NFUS) transducers in the tip of the catheter might provide an image of the evolving pathological lesion during energy delivery.

    Background: Radiofrequency (RF) catheter ablation has been effective in arrhythmia treatment, but no technology has allowed lesion formation to be visualized in real time in vivo.

    Methods: RF catheter ablations were performed in vivo with the goal to create transmural atrial lesions and large…

    Objectives: Visualizing myocardium with near field ultrasound (NFUS) transducers in the tip of the catheter might provide an image of the evolving pathological lesion during energy delivery.

    Background: Radiofrequency (RF) catheter ablation has been effective in arrhythmia treatment, but no technology has allowed lesion formation to be visualized in real time in vivo.

    Methods: RF catheter ablations were performed in vivo with the goal to create transmural atrial lesions and large ventricular lesions. RF lesion formation was imaged in real time using M-mode, tissue Doppler, and strain rate information from the NFUS open irrigated RF ablation catheter incorporating 4 ultrasound transducers (1 axial and 3 radial), and growth kinetics were analyzed. Nineteen dogs underwent ablation in the right and left atria (n = 185), right ventricle (n = 67), and left ventricle (n = 66). Lesions were echolucent with tissue strain rate by NFUS.

    Results: Lesion growth frequently progressed from epicardium to endocardium in thin-walled tissue. The half time of lesion growth was 5.5 ± 2.8 s in thin-walled and 9.7 ± 4.3 s in thick-walled tissue. Latency of lesion onset was seen in 57% of lesions ranging from 1 to 63.8 s. Tissue edema (median 25% increased wall thickness) formed immediately upon lesion formation in 83%, and intramyocardial steam was seen in 71% of cases.

    Conclusions: NFUS was effective in imaging RF catheter ablation lesion formation in real time. It was useful in assessing the dynamics of lesion growth and could visualize impending steam pops. It may be a useful technology to improve both safety and efficacy of RF catheter ablation.

    Publicatie weergeven
  • Near-Field Ultrasound Imaging During Radiofrequency Catheter Ablation: Tissue Thickness and Epicardial Wall Visualization and Assessment of Radiofrequency Ablation Lesion Formation and Depth

    Circ Arrhythm Electrophysiol . 2017 Dec;10(12):e005295

    Background: Safe and successful radiofrequency catheter ablation depends on creation of transmural lesions without collateral injury to contiguous structures. Near-field ultrasound (NFUS) imaging through transducers in the tip of an ablation catheter may provide important information about catheter contact, wall thickness, and ablation lesion formation.

    Methods and results: NFUS imaging was performed using a specially designed open-irrigated radiofrequency ablation catheter incorporating…

    Background: Safe and successful radiofrequency catheter ablation depends on creation of transmural lesions without collateral injury to contiguous structures. Near-field ultrasound (NFUS) imaging through transducers in the tip of an ablation catheter may provide important information about catheter contact, wall thickness, and ablation lesion formation.

    Methods and results: NFUS imaging was performed using a specially designed open-irrigated radiofrequency ablation catheter incorporating 4 ultrasound transducers. Tissue/phantom thickness was measured in vitro with varying contact angles. In vivo testing was performed in 19 dogs with NFUS catheters positioned in 4 chambers. Wall thickness measurements were made at 222 sites (excluding the left ventricle) and compared with measurements from intracardiac echocardiography. Imaging was used to identify the epicardium with saline infusion into the pericardial space at 39 sites. In vitro, the measured exceeded actual tissue/phantom thickness by 13% to 20%. In vivo, NFUS reliably visualized electrode-tissue contact, but sensitivity of epicardial imaging was 92%. The chamber wall thickness measured by NFUS correlated well with intracardiac echocardiography (r=0.86; P<0.0001). Sensitivity of lesion identification by NFUS was 94% for atrial and 95% for ventricular ablations. NFUS was the best parameter to predict lesion depth in right and left ventricle (r=0.47; P<0.0001; multiple regression P=0.0025). Lesion transmurality was correctly identified in 87% of atrial lesions.

    Conclusions: NFUS catheter imaging reliably assesses electrode-tissue contact and wall thickness. Its use during radiofrequency catheter ablation may allow the operator to assess the depth of ablation required for transmural lesion formation to optimize power delivery.

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  • Tachycardia-induced silencing of subcellular Ca2+ signaling in atrial myocytes

    J Clin Invest . 2014 Nov;124(11):4759-72

    Atrial fibrillation (AF) is characterized by sustained high atrial activation rates and arrhythmogenic cellular Ca2+ signaling instability; however, it is not clear how a high atrial rate and Ca2+ instability may be related. Here, we characterized subcellular Ca2+ signaling after 5 days of high atrial rates in a rabbit model. While some changes were similar to those in persistent AF, we identified a distinct pattern of stabilized subcellular Ca2+ signaling. Ca2+ sparks, arrhythmogenic Ca2+…

    Atrial fibrillation (AF) is characterized by sustained high atrial activation rates and arrhythmogenic cellular Ca2+ signaling instability; however, it is not clear how a high atrial rate and Ca2+ instability may be related. Here, we characterized subcellular Ca2+ signaling after 5 days of high atrial rates in a rabbit model. While some changes were similar to those in persistent AF, we identified a distinct pattern of stabilized subcellular Ca2+ signaling. Ca2+ sparks, arrhythmogenic Ca2+ waves, sarcoplasmic reticulum (SR) Ca2+ leak, and SR Ca2+ content were largely unaltered. Based on computational analysis, these findings were consistent with a higher Ca2+ leak due to PKA-dependent phosphorylation of SR Ca2+ channels (RyR2s), fewer RyR2s, and smaller RyR2 clusters in the SR. We determined that less Ca2+ release per [Ca2+]i transient, increased Ca2+ buffering strength, shortened action potentials, and reduced L-type Ca2+ current contribute to a stunning reduction of intracellular Na+ concentration following rapid atrial pacing. In both patients with AF and in our rabbit model, this silencing led to failed propagation of the [Ca2+]i signal to the myocyte center. We conclude that sustained high atrial rates alone silence Ca2+ signaling and do not produce Ca2+ signaling instability, consistent with an adaptive molecular and cellular response to atrial tachycardia.

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  • Visualizing intramyocardial steam formation with a radiofrequency ablation catheter incorporating near-field ultrasound

    J Cardiovasc Electrophysiol . 2013 Dec;24(12):1403-9

    Introduction: Steam pops are a risk of irrigated RF ablation even when limiting power delivery. There is currently no way to predict gas formation during ablation. It would be useful to visualize intramyocardial gas formation prior to a steam pop occurring using near-field ultrasound integrated into a RF ablation catheter.

    Methods and results: In an in vivo open-chest ovine model (n = 9), 86 lesions were delivered to the epicardial surface of the ventricles. Energy was delivered for…

    Introduction: Steam pops are a risk of irrigated RF ablation even when limiting power delivery. There is currently no way to predict gas formation during ablation. It would be useful to visualize intramyocardial gas formation prior to a steam pop occurring using near-field ultrasound integrated into a RF ablation catheter.

    Methods and results: In an in vivo open-chest ovine model (n = 9), 86 lesions were delivered to the epicardial surface of the ventricles. Energy was delivered for 15-60 seconds, to achieve lesions with and without steam pops, based on modeling data. The ultrasound image was compared to a digital audio recording from within the pericardium by a blinded observer. Of 86 lesions, 28 resulted in an audible steam pop. For lesions that resulted in a steam pop compared to those that did not (n = 58), the mean power delivered was 8.0 ± 1.8 W versus 6.7 ± 2.0 W, P = 0.006. A change in US contrast due to gas formation in the tissue occurred in all lesions that resulted in a steam pop. In 4 ablations, a similar change in US contrast was observed in the tissue and RF delivery was stopped; in these cases, no pop occurred. The mean depth of gas formation was 0.9 ± 0.8 mm, which correlated with maximal temperature predicted by modeling. Changes in US contrast occurred 7.6 ± 7.2 seconds before the impedance rise and 7.9 ± 6.2 seconds (0.1-17.0) before an audible pop.

    Conclusion: Integrated US in an RF ablation catheter is able to visualize gas formation intramyocardially several seconds prior to a steam pop occurring. This technology may help prevent complications arising from steam pops.

    Keywords: animal model; catheter ablation; pericardium; steam pops; ultrasound.

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  • Real-time lesion assessment using a novel combined ultrasound and radiofrequency ablation catheter

    Heart Rhythm . 2011 Feb;8(2):304-12

    Background: Assessment of lesion size and transmurality is currently via indirect measures. Real-time image assessment may allow ablation parameters to be titrated to achieve transmurality and reduce recurrences due to incomplete lesions.

    Objective: The purpose of this study was to visualize lesion formation in real time using a novel combined ultrasound and externally irrigated ablation catheter.

    Methods: In an in vivo open-chest sheep model, 144 lesions were delivered in 11…

    Background: Assessment of lesion size and transmurality is currently via indirect measures. Real-time image assessment may allow ablation parameters to be titrated to achieve transmurality and reduce recurrences due to incomplete lesions.

    Objective: The purpose of this study was to visualize lesion formation in real time using a novel combined ultrasound and externally irrigated ablation catheter.

    Methods: In an in vivo open-chest sheep model, 144 lesions were delivered in 11 sheep to both the atria and the ventricles, while lesion development was monitored in real time. Energy was delivered for a minimum of 15 seconds and a maximum of 60 seconds, with a range of powers, to achieve different lesion depths. Twenty-two lesions were also delivered endocardially. The ultrasound appearance was assessed and compared with the pathological appearance by four independent blinded observers.

    Results: For the ventricular lesions (n = 126), the mean power delivered was 6.1 ± 2.0 W, with a mean impedance of 394.7 ± 152.4 Ω and with an impedance drop of 136.4 ± 100.1 Ω. Lesion depths varied from 0 to 10 mm, with a median depth of 3.5 mm. At tissue depths up to 5 mm, changes in ultrasound contrast correlated well (r = 0.79, R(2) = 0.62) with tissue necrosis. The depth of ultrasound contrast correlated poorly with the depth of the zone of hemorrhage (r = 0.33, R(2) = 0.11), and impedance change correlated poorly with lesion depth (r = 0.29, R(2) = 0.08).

    Conclusion: Real-time lesion assessment using high-frequency ultrasound integrated into an ablation catheter is feasible and allows differentiation between true necrosis and hemorrhage. This may lead to safer and more efficient power delivery, allowing more effective lesion formation.

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  • Miniaturized ultrasound scanner by electrowetting

    Appl. Phys. Lett. 97, 064102 (2010)

    An ultrasound imaging technology based on electrowetting has been developed and integrated in a miniaturized ultrasound scanner. The feasibility of scanning the ultrasound beam of a single-piston transducer in a three-dimensional space by using electrowetting is demonstrated. The technology has a high potential to be embedded in devices where size restrictions do not allow the use of traditional ultrasound phased-array transducers.

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  • Distinct contractile and molecular differences between two goat models of atrial dysfunction: AV block-induced atrial dilatation and atrial fibrillation

    J Mol Cell Cardiol . 2009 Mar;46(3):385-94

    Atrial dilatation is an independent risk factor for thromboembolism in patients with and without atrial fibrillation (AF). In many patients, atrial dilatation goes along with depressed contractile function of the dilated atria. While some mechanisms causing atrial contractile dysfunction in fibrillating atria have been addressed previously, the cellular and molecular mechanisms of atrial contractile remodeling in dilated atria are unknown. This study characterized in vivo atrial contractile…

    Atrial dilatation is an independent risk factor for thromboembolism in patients with and without atrial fibrillation (AF). In many patients, atrial dilatation goes along with depressed contractile function of the dilated atria. While some mechanisms causing atrial contractile dysfunction in fibrillating atria have been addressed previously, the cellular and molecular mechanisms of atrial contractile remodeling in dilated atria are unknown. This study characterized in vivo atrial contractile function in a goat model of atrial dilatation and compared it to a goat model of AF. Atrial hypocontractility appeared to have distinct molecular contributors in different types of atrial remodeling.

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  • Blockade of atrial-specific K+-currents increases atrial but not ventricular contractility by enhancing reverse mode Na+/Ca2+-exchange

    Cardiovasc Res . 2007 Jan 1;73(1):37-47

    Background: AVE0118 (2'-{[2-(4-Methoxy-phenyl)-acetylamino]-methyl}-biphenyl-2-carboxylic acid (2-pyridin-3-yl-ethyl)-amide) blocks atrial ultrarapid delayed rectifier currents (I(Kur)) and prolongs the atrial action potential (AP) plateau without affecting ventricular repolarisation. In patients with atrial contractile dysfunction due to atrial tachyarrhythmias, this response might increase atrial contractility without risk of ventricular proarrhythmia. This study was designed to evaluate the…

    Background: AVE0118 (2'-{[2-(4-Methoxy-phenyl)-acetylamino]-methyl}-biphenyl-2-carboxylic acid (2-pyridin-3-yl-ethyl)-amide) blocks atrial ultrarapid delayed rectifier currents (I(Kur)) and prolongs the atrial action potential (AP) plateau without affecting ventricular repolarisation. In patients with atrial contractile dysfunction due to atrial tachyarrhythmias, this response might increase atrial contractility without risk of ventricular proarrhythmia. This study was designed to evaluate the inotropic mechanisms of AVE0118.

    Methods and results: In isometrically contracting atrial trabeculae, AVE0118 increased contractile force by 55.4% in sinus rhythm patients (n = 9) and by 107.4% in patients with atrial fibrillation (n = 8). In freshly isolated canine atrial myocytes studied under perforated patch current clamp (37 degrees C), AVE0118 increased myocyte fractional shortening from 3.8+/-0.6 to 9.6+/-0.8% and prolonged action potential duration at 30% repolarisation from 9+/-2 to 102+/-11 ms. In action potential clamp, peak Ca2+ inward current (I(CaL)) current declined from 5.5+/-1.3 pA/pF during control to 4.1+/-0.7 pA/pF when an AP recorded in the presence of AVE0118 was used as command waveform. However, I(CaL) was more sustained with AVE0118 and the time integral did not change (135+/-37 vs. 173+/-30 pA/pFms, p = ns). Importantly, blockade of reverse mode Na+/Ca2+-exchanger activity with 5 microM KBR7943 or using a Na+-free pipette solution abolished the positive inotropic effect of the AP recorded in the presence of AVE0118. In ventricular myocytes AVE0118 did not elicit a positive inotropic response.

    Conclusions: Block of I(Kur) by AVE0118 enhances atrial contractility both in patients with sinus rhythm and atrial fibrillation. The positive inotropic effect is atrial-specific and due to the changes of the action potential configuration which enhances Ca2+ entry via reverse mode Na+/Ca2+ exchange.

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  • AVE0118, blocker of the transient outward current (I(to)) and ultrarapid delayed rectifier current (I(Kur)), fully restores atrial contractility after cardioversion of atrial fibrillation in the goat

    Circulation . 2006 Sep 19;114(12):1234-42

    Background: The loss of atrial contractile function after cardioversion of atrial fibrillation (AF) contributes to the thromboembolic risk associated with AF. The newly developed blocker of the transient outward current (I(to)) and ultrarapid delayed rectifier current (I(Kur)) AVE0118 prolongs atrial action potential duration and might therefore enhance atrial contractility. We compared the ability of AVE0118 to restore atrial contraction after cardioversion of AF with the efficacy of…

    Background: The loss of atrial contractile function after cardioversion of atrial fibrillation (AF) contributes to the thromboembolic risk associated with AF. The newly developed blocker of the transient outward current (I(to)) and ultrarapid delayed rectifier current (I(Kur)) AVE0118 prolongs atrial action potential duration and might therefore enhance atrial contractility. We compared the ability of AVE0118 to restore atrial contraction after cardioversion of AF with the efficacy of conventional positive inotropic compounds in the goat model of AF.

    Methods and results: Eighteen goats were chronically instrumented with epicardial electrodes, a pressure transducer in the right atrium, and piezoelectric crystals to measure right atrial diameter. Atrial contractility and refractoriness and QT duration were measured before and after 1 week (3 to 8 days) of AF induced by repetitive burst pacing. After 1 week of AF, atrial contractility during sinus rhythm or slow atrial pacing was reduced to <10%. Digoxin and dobutamine failed to increase atrial contractility. EMD57033 restored 41% and BayY5959 restored 48% of atrial contractility at baseline. BayY5959 significantly prolonged QT duration by 24.7%. AVE0118 enhanced atrial contraction to 156% of the baseline value. The positive inotropic effect was accompanied by a pronounced prolongation of atrial action potential duration and refractoriness, whereas QT duration remained unchanged.

    Conclusions: Conventional positive inotropic drugs showed limited effect on atrial contractility after cardioversion of AF or produced QT prolongation. In contrast, the I(to)/I(Kur) blocker AVE0118 fully restored atrial contraction without proarrhythmic effects on the ventricle.

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  • Autocrine production of prostaglandin F2alpha enhances phenotypic transformation of normal rat kidney fibroblasts

    Am J Physiol Cell Physiol . 2005 Jul;289(1):C130-7

    We have used normal rat kidney (NRK) fibroblasts as an in vitro model system to study cell transformation. These cells obtain a transformed phenotype upon stimulation with growth-modulating factors such as retinoic acid (RA) or transforming growth factor-beta (TGF-beta). Patch-clamp experiments showed that transformation is paralleled by a profound membrane depolarization from around -70 to -20 mV. This depolarization is caused by a compound in the medium conditioned by transformed NRK cells…

    We have used normal rat kidney (NRK) fibroblasts as an in vitro model system to study cell transformation. These cells obtain a transformed phenotype upon stimulation with growth-modulating factors such as retinoic acid (RA) or transforming growth factor-beta (TGF-beta). Patch-clamp experiments showed that transformation is paralleled by a profound membrane depolarization from around -70 to -20 mV. This depolarization is caused by a compound in the medium conditioned by transformed NRK cells, which enhances intracellular Ca2+ levels and thereby activates Ca2+-dependent Cl- channels. This compound was identified as prostaglandin F2alpha (PGF2alpha) using electrospray ionization mass spectrometry. The active concentration in the medium conditioned by transformed NRK cells as determined using an enzyme immunoassay was 19.7 +/- 2.5 nM (n = 6), compared with 1.5 +/- 0.1 nM (n = 3) conditioned by nontransformed NRK cells. Externally added PGF2alpha was able to trigger NRK cells that had grown to density arrest to restart their proliferation. This proliferation was inhibited when the FP receptor (i.e., natural receptor for PGF2alpha) was blocked by AL-8810. RA-induced phenotypic transformation of NRK cells was partially (approximately 25%) suppressed by AL-8810. Our results demonstrate that PGF2alpha acts as an autocrine enhancer and paracrine inducer of cell transformation and suggest that it may play a crucial role in carcinogenesis in general.

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  • Modeling action potential generation and propagation in NRK fibroblasts

    Am J Physiol Cell Physiol . 2004 Oct;287(4):C851-65

    Normal rat kidney (NRK) fibroblasts change their excitability properties through the various stages of cell proliferation. The present mathematical model has been developed to explain excitability of quiescent (serum deprived) NRK cells. It includes as cell membrane components, on the basis of patch-clamp experiments, an inwardly rectifying potassium conductance (G(Kir)), an L-type calcium conductance (G(CaL)), a leak conductance (G(leak)), an intracellular calcium-activated chloride…

    Normal rat kidney (NRK) fibroblasts change their excitability properties through the various stages of cell proliferation. The present mathematical model has been developed to explain excitability of quiescent (serum deprived) NRK cells. It includes as cell membrane components, on the basis of patch-clamp experiments, an inwardly rectifying potassium conductance (G(Kir)), an L-type calcium conductance (G(CaL)), a leak conductance (G(leak)), an intracellular calcium-activated chloride conductance [G(Cl(Ca))], and a gap junctional conductance (G(gj)), coupling neighboring cells in a hexagonal pattern. This membrane model has been extended with simple intracellular calcium dynamics resulting from calcium entry via G(CaL) channels, intracellular buffering, and calcium extrusion. It reproduces excitability of single NRK cells and cell clusters and intercellular action potential (AP) propagation in NRK cell monolayers. Excitation can be evoked by electrical stimulation, external potassium-induced depolarization, or hormone-induced intracellular calcium release. Analysis shows the roles of the various ion channels in the ultralong ( approximately 30 s) NRK cell AP and reveals the particular role of intracellular calcium dynamics in this AP. We support our earlier conclusion that AP generation and propagation may act as a rapid mechanism for the propagation of intracellular calcium waves, thus contributing to fast intercellular calcium signaling. The present model serves as a starting point to further analyze excitability changes during contact inhibition and cell transformation.

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  • Ionic basis for excitability of normal rat kidney (NRK) fibroblasts

    J Cell Physiol . 2003 Sep;196(3):493-503

    Ionic membrane conductances of normal rat kidney (NRK) fibroblasts were characterized by whole-cell voltage-clamp experiments on single cells and small cell clusters and their role in action potential firing in these cells and in monolayers was studied in current-clamp experiments. Activation of an L-type calcium conductance (GCaL) is responsible for the initiation of an action potential, a calcium-activated chloride conductance (GCl(Ca)) determines the plateau phase of the action potential…

    Ionic membrane conductances of normal rat kidney (NRK) fibroblasts were characterized by whole-cell voltage-clamp experiments on single cells and small cell clusters and their role in action potential firing in these cells and in monolayers was studied in current-clamp experiments. Activation of an L-type calcium conductance (GCaL) is responsible for the initiation of an action potential, a calcium-activated chloride conductance (GCl(Ca)) determines the plateau phase of the action potential, and an inwardly rectifying potassium conductance (GKir) is important for the generation of a resting potential of approximately -70 mV and contributes to action potential depolarization and repolarization. The unique property of the excitability mechanism is that it not only includes voltage-activated conductances (GCaL, GKir) but that the intracellular calcium dynamics is also an essential part of it (via GCl(Ca)). Excitability was found to be an intrinsic property of a fraction (approximately 25%) of the individual cells, and not necessarily dependent on gap junctional coupling of the cells in a monolayer. Electrical coupling of a patched cell to neighbor cells in a small cluster improved the excitability because all small clusters were excitable. Furthermore, cells coupled in a confluent monolayer produced broader action potentials. Thus, electrical coupling in NRK cells does not merely serve passive conduction of stereotyped action potentials, but also seems to play a role in shaping the action potential.

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  • Prostaglandin F2 alpha induces unsynchronized intracellular calcium oscillations in monolayers of gap junctionally coupled NRK fibroblasts

    Pflugers Arch . 2003 Oct;447(1):78-86

    We investigated the intracellular calcium oscillations induced by prostaglandin F2alpha (PGF2alpha) in individual cells of confluent, gap junction-coupled monolayers of normal rat kidney (NRK) fibroblasts. PGF2alpha (1000 nM) induced oscillations in more than 90% of the cells in the monolayer, but the frequency of these oscillations was highly variable between individual cells (0.2-1.4 min(-1)). The initial calcium peak resulted from calcium release from IP3-sensitive stores, while subsequent…

    We investigated the intracellular calcium oscillations induced by prostaglandin F2alpha (PGF2alpha) in individual cells of confluent, gap junction-coupled monolayers of normal rat kidney (NRK) fibroblasts. PGF2alpha (1000 nM) induced oscillations in more than 90% of the cells in the monolayer, but the frequency of these oscillations was highly variable between individual cells (0.2-1.4 min(-1)). The initial calcium peak resulted from calcium release from IP3-sensitive stores, while subsequent calcium transients were mediated by interplay between both IP3-sensitive calcium stores and calcium influx. The oscillation frequency was increased by sensitizing the IP3 receptor with thimerosal (10 microM) and depended on the extracellular calcium concentration. Thapsigargin (5 nM), which inhibits reuptake of calcium into the stores, only seemed to reduce the amplitude of the oscillation. Patch-clamp experiments revealed that PGF2alpha did not inhibit electrical coupling of the NRK cells in the monolayer. Gap junctional permeability of NRK cells thus appears to be sufficient to allow electrical coupling, resulting in a uniform membrane potential throughout the entire monolayer, but insufficient to synchronize the intracellular calcium oscillations upon PGF2alpha stimulation.

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  • Lipid factor (bVLF) from bovine vitreous body evokes in EGFR-T17 cells a Ca2+-dependent K+ current associated with inositol 1,4,5-trisphosphate-independent Ca2+ mobilization

    J Cell Physiol . 2003 Apr;195(1):108-18

    Bovine vitreous lipid factor (bVLF) is a complex phospholipid isolated from bovine vitreous body with strong Ca(2+)-mobilizing activity. In this study, the effects of bVLF on membrane potential were investigated in EGFR-T17 fibroblasts with the whole-cell patch clamp technique on monolayer cells, as well as with the fluorescent dye bis-oxonol as membrane potential-sensitive probe on monolayer and suspension cells. bVLF induced a transient hyperpolarization characterized by an initial peak and…

    Bovine vitreous lipid factor (bVLF) is a complex phospholipid isolated from bovine vitreous body with strong Ca(2+)-mobilizing activity. In this study, the effects of bVLF on membrane potential were investigated in EGFR-T17 fibroblasts with the whole-cell patch clamp technique on monolayer cells, as well as with the fluorescent dye bis-oxonol as membrane potential-sensitive probe on monolayer and suspension cells. bVLF induced a transient hyperpolarization characterized by an initial peak and subsequent return to resting membrane potential levels within 1-2 min. The increase of [Ca(2+)](i) was concomitant with an outward current responsible for the hyperpolarizing response. Results with: (a) high [K(+)](o) media; (b) the monovalent cation ionophore gramicidin; and (c) substitution of K(+) with Cs(+) in the intracellular solution were consistent with the involvement of K(+) channels. The bVLF-induced hyperpolarization was blocked by the K(+) channel blockers, quinine and tetraethylamonium chloride, and partially affected by 4-aminopyridine. The calcium ionophore ionomycin caused a similar hyperpolarization as bVLF. When intracellular calcium was buffered by adding BAPTA to the pipette solution, bVLF-activated outward current was prevented. Moreover, the hyperpolarization response was strongly reduced at low doses (3 nM) of specific Ca(2+)-activated K(+) channel blockers, charybdotoxin and iberiotoxin. Based on these observations we conclude that bVLF hyperpolarizes the cells via the activation of a Ca(2+)-dependent K(+) current. In addition, it was observed that bVLF did not have a significant effect on intercellular communication measured by a single patch-electrode technique. Thus, membrane potential changes appeared to belong to the earliest cellular responses triggered by bVLF, and are closely associated with phosphatidic acid-dependent [Ca(2+)](i) mobilization.

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  • Besides affecting intracellular calcium signaling, 2-APB reversibly blocks gap junctional coupling in confluent monolayers, thereby allowing measurement of single-cell membrane currents in undissociated cells

    FASEB J . 2003 May;17(8):941-3

    2-aminoethoxydiphenyl borate (2-APB) has been widely used as a blocker of the IP3 receptor and TRP channels, including store-operated calcium channels. We now show in monolayers of normal rat kidney cells (NRK/49F) that 2-APB completely and reversibly blocks gap junctional intercellular communication at concentrations similar to that required for inhibition of PGF2alpha-induced increases in intracellular calcium. Gap junctional conductances between NRK cells were estimated with single-electrode…

    2-aminoethoxydiphenyl borate (2-APB) has been widely used as a blocker of the IP3 receptor and TRP channels, including store-operated calcium channels. We now show in monolayers of normal rat kidney cells (NRK/49F) that 2-APB completely and reversibly blocks gap junctional intercellular communication at concentrations similar to that required for inhibition of PGF2alpha-induced increases in intracellular calcium. Gap junctional conductances between NRK cells were estimated with single-electrode patch-clamp measurements and were fully blocked by 2-APB (50 microM), when applied extracellularly but not via the patch pipette. Half maximal inhibition (IC50) of electrical coupling in NRK cells was achieved at 5.7 microM. Similar results were obtained for human embryonic kidney epithelial cells (HEK293/tsA201) with an IC50 of 10.3 microM. Using 2-APB as an electrical uncoupler of monolayer cells, we could thus measure inward rectifier potassium, L-type calcium, and calcium-dependent chloride membrane currents in confluent NRK monolayers, with properties similar to those in dissociated NRK cells in the absence of 2-APB. The electrical uncoupling action described here is a new 2-APB property that promises to provide a powerful pharmacological tool to study single-cell properties in cultured confluent monolayers and intact tissues by electrical and chemical uncoupling of the cells without the need of prior dissociation.

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  • Fenamates: a novel class of reversible gap junction blockers

    J Pharmacol Exp Ther . 2001 Sep;298(3):1033-41

    The effect of fenamates on gap junctional intercellular communication was investigated in monolayers of normal rat kidney (NRK) fibroblasts and of SKHep1 cells overexpressing the gap junction protein connexin43 (Cx43). Using two different methods to study gap junctional intercellular communication, single electrode voltage-clamp step response measurements and dye microinjection, we show that fenamates are reversible blockers of Cx43-mediated intercellular communication. After adding fenamates…

    The effect of fenamates on gap junctional intercellular communication was investigated in monolayers of normal rat kidney (NRK) fibroblasts and of SKHep1 cells overexpressing the gap junction protein connexin43 (Cx43). Using two different methods to study gap junctional intercellular communication, single electrode voltage-clamp step response measurements and dye microinjection, we show that fenamates are reversible blockers of Cx43-mediated intercellular communication. After adding fenamates to a confluent monolayer of electrically coupled NRK fibroblasts, the voltage step-induced capacitive current transient changed from a transient characteristic for charging multiple coupled cell capacitances to one characteristic for a single cell in isolation. The capacitance of completely uncoupled cells was 19.7 +/- 1.0 pF (mean +/- S.E.M.; n = 11). Junctional conductance between the patched cell and the surrounding cells in the monolayer changed from >140.7 +/- 9.6 nS (mean +/- S.E.M.; n = 14) to <1.4 +/- 0.4 nS (mean +/- S.E.M.; n = 11) after uncoupling. Electrical coupling could be restored to >51.8 +/- 4.2 nS (mean +/- S.E.M.; n = 11) by washout of the fenamates. Voltage-clamp step response measurements showed that the potency of fenamates in inhibiting electrical coupling decreases in the order meclofenamic acid > niflumic acid > flufenamic acid. The half-maximal concentration determined by dye-coupling experiments was 25 and 40 microM for meclofenamic acid and flufenamic acid, respectively. Voltage-clamp step response measurements in confluent monolayers of SKHep1 cells that had been stably transfected with Cx43 revealed that fenamates are potent blockers of Cx43-mediated intercellular communication. In conclusion, fenamates represent a novel class of reversible gap junction blockers that can be used to study the role of Cx43-mediated gap junctional intercellular communication in biological processes.

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Patenten

  • A METHOD OF REGISTERING ULTRASOUND IMAGES TO AN ANATOMICAL MAP

    Toegekend WO2022053440

    A mechanism for registering ultrasound images with an anatomical map generated using a dielectric imaging process. The positions of electrodes that move with the ultrasound probe are monitored using the same dielectric imaging system that generated the anatomical map. The position at which ultrasound images are generated is captured, and this information is used to register the ultrasound image(s) with respect to the anatomical map.

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  • INTRALUMINAL MEDICAL IMAGING INTERFACE DEVICES AND SYSTEMS

    Toegekend WO2019211150

    An intraluminal medical imaging interface device includes an arm assembly comprising one or more longitudinal members and one or more joints coupled to the one or more longitudinal members, and a head assembly coupled to a distal portion of the arm assembly and comprising a proximal portion coupled to the distal portion of the arm assembly and a distal portion. The distal portion of the head assembly includes a mechanical coupling and an electrical coupling configured to separably connect to an…

    An intraluminal medical imaging interface device includes an arm assembly comprising one or more longitudinal members and one or more joints coupled to the one or more longitudinal members, and a head assembly coupled to a distal portion of the arm assembly and comprising a proximal portion coupled to the distal portion of the arm assembly and a distal portion. The distal portion of the head assembly includes a mechanical coupling and an electrical coupling configured to separably connect to an intraluminal imaging catheter and to transmit electrical signals between a console and the intraluminal imaging catheter. The arm assembly is configured to couple to a surface to maintain the head assembly at a first position and an orientation with respect to a patient without continued support by an operator. Associated devices, systems, and methods are also provided.

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  • ULTRASOUND TRACKING AND VISUALIZATION

    Toegekend WO2019096810

    The invention relates to an ultrasound visualization system (111, 311) for tracking a position of an interventional device (112) based on a stream of live ultrasound images (113). A processor (117) receives the stream of live ultrasound images (113), extracts a reference image (118) that includes an anatomical feature (119), extracts from the stream of live ultrasound (113) images a current image (120) that includes a portion of the anatomical feature (119) and a portion of the interventional…

    The invention relates to an ultrasound visualization system (111, 311) for tracking a position of an interventional device (112) based on a stream of live ultrasound images (113). A processor (117) receives the stream of live ultrasound images (113), extracts a reference image (118) that includes an anatomical feature (119), extracts from the stream of live ultrasound (113) images a current image (120) that includes a portion of the anatomical feature (119) and a portion of the interventional device (112) at a current position (121), matches the portion of the anatomical feature in the current image 120 with the anatomical feature in the reference image (118) to determine a spatial relationship between the current position of the interventional device and the anatomical feature in the reference image (118), and indicates, in the reference image (118), the current position (121) of the interventional device (112), based on the determined spatial relationship.

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  • ULTRASOUND IMAGE PROCESSING

    Toegekend WO2019052965

    Disclosed is an ultrasound image processing apparatus (5) comprising an image processor arrangement (50) adapted to receive a plurality of ultrasound images (150), each ultrasound image imaging an invasive medical device (15) relative to an anatomical feature of interest (151) during a particular phase of a cardiac cycle, said anatomical feature of interest having a different shape at different phases of the cardiac cycle, the plurality of ultrasound images covering at least two cardiac cycles…

    Disclosed is an ultrasound image processing apparatus (5) comprising an image processor arrangement (50) adapted to receive a plurality of ultrasound images (150), each ultrasound image imaging an invasive medical device (15) relative to an anatomical feature of interest (151) during a particular phase of a cardiac cycle, said anatomical feature of interest having a different shape at different phases of the cardiac cycle, the plurality of ultrasound images covering at least two cardiac cycles during which the invasive medical device is displaced relative to the anatomical feature of interest; compile a plurality of groups of the ultrasound images, wherein the ultrasound images in each group belong to the same phase of said cardiac cycles; and for each group: determine the displacement of the invasive medical device relative to the anatomical feature of interest between at least two ultrasound images in said group; and generate an augmented ultrasound image from one of the ultrasound images of the at least two ultrasound images by removing a shadow region (17) on the anatomical feature of interest caused by the invasive medical device from said ultrasound image based on the determined displacement of the invasive medical device. Also disclosed are an ultrasound imaging system comprising such an ultrasound image processing apparatus, a method to be implemented by such an ultrasound image processing apparatus and a computer program product facilitating the implementation of such a method.

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  • ULTRASOUND IMAGE PROCESSING

    Toegekend WO2019052968

    Disclosed is an ultrasound image processing apparatus (5) comprising an image processor arrangement (50) adapted to receive a first sequence (100') of ultrasound images (150) imaging an anatomical feature of interest (151) during a first full cardiac cycle in the absence of an invasive medical device (15) in said ultrasound images, each ultrasound image corresponding to a different phase of said cardiac cycle; receive a further sequence (100') of ultrasound images (150) imaging the anatomical…

    Disclosed is an ultrasound image processing apparatus (5) comprising an image processor arrangement (50) adapted to receive a first sequence (100') of ultrasound images (150) imaging an anatomical feature of interest (151) during a first full cardiac cycle in the absence of an invasive medical device (15) in said ultrasound images, each ultrasound image corresponding to a different phase of said cardiac cycle; receive a further sequence (100') of ultrasound images (150) imaging the anatomical feature of interest (151) during a further full cardiac cycle in the presence of the invasive medical device (15) in said ultrasound images, each ultrasound image corresponding to a different phase of said cardiac cycle said invasive medical device (15) at least partially obscuring the anatomical feature of interest, and for each ultrasound image of the further sequence: track the location of the invasive medical device in the ultrasound image; isolate the invasive medical device from the ultrasound image; and insert the isolated invasive medical device into an ultrasound image of the first sequence of a corresponding phase of the cardiac cycle in the tracked location; and control a display device to display the first sequence of ultrasound images including the inserted invasive medical device. Also disclosed are an ultrasound imaging system comprising such an ultrasound image processing apparatus and a computer program product facilitating the configuration of such an image processing apparatus in accordance with embodiments of the present invention.

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  • ABLATION CATHETER, CATHETER ARRANGEMENT AND SYSTEM FOR PROVIDING ABLATIVE TREATMENT

    Toegekend WO2019042769

    An ablation catheter (100) for ablative treatment of ventricular tachycardia is provided. The catheter comprises a shaft (102) which is capable of being guided to the tissue to be ablated. An ablation element (104) for ablating tissue is mounted on the shaft. The catheter further comprises a plurality of ultrasound transducer arrays (106) for obtaining images of myocardial tissue. The arrays are positioned separately from each other around the circumference of the shaft. The catheter can adopt…

    An ablation catheter (100) for ablative treatment of ventricular tachycardia is provided. The catheter comprises a shaft (102) which is capable of being guided to the tissue to be ablated. An ablation element (104) for ablating tissue is mounted on the shaft. The catheter further comprises a plurality of ultrasound transducer arrays (106) for obtaining images of myocardial tissue. The arrays are positioned separately from each other around the circumference of the shaft. The catheter can adopt a folded configuration and a deployed configuration. In the folded configuration, the arrays are positioned against or close to the shaft thereby facilitating insertion and guiding of the catheter. In the deployed configuration, the arrays are more separated from the shaft than in the folded configuration. Further provided is a catheter arrangement including the ablation catheter, and a system for providing ablative treatment comprising the ablation catheter or catheter arrangement.

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  • REGISTRATION OF X-RAY AND ULTRASOUND IMAGES

    Toegekend WO2019020498

    An image registration system (111) for registering a live stream of ultrasound images (112) of a beamforming ultrasound probe (113) with an X-ray image (114) is described. The image registration (111) system identifies, from the X-ray image (114), the position of a medical device (116) represented in the X-ray image (114); and determines, based on ultrasound signals transmitted between the beamforming ultrasound probe (113) and an ultrasound transducer (115) disposed on the medical device…

    An image registration system (111) for registering a live stream of ultrasound images (112) of a beamforming ultrasound probe (113) with an X-ray image (114) is described. The image registration (111) system identifies, from the X-ray image (114), the position of a medical device (116) represented in the X-ray image (114); and determines, based on ultrasound signals transmitted between the beamforming ultrasound probe (113) and an ultrasound transducer (115) disposed on the medical device (116), a location of the ultrasound transducer (115) respective the beamforming ultrasound probe (113). Each ultrasound image from the live stream (112) is registered with the X-ray (114) image based on the identified position of the medical device (116). The registration includes determining an offset from said identified position that is based on i) a predetermined spatial relationship of the ultrasound transducer (115) respective the medical device (116) and ii) the determined location of the ultrasound transducer (115) respective the beamforming ultrasound probe (113).

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  • NAVIGATION PLATFORM FOR A MEDICAL DEVICE, PARTICULARLY AN INTRACARDIAC CATHETER

    Toegekend WO2018115200

    The invention relates to a system for assisting in navigating a medical device (1) in a region of a patient body, such as a cardiac chamber. The system comprises a unit (5) for providing a three-dimensional model of the region and an ultrasound probe (2) for acquiring image signals of the region of the patient body. At least one an ultrasound sensor (6) is attached to the medical device (1) for sensing ultrasound signals emitted by the 5 ultrasound probe (2) and a tracking unit (7) determines a…

    The invention relates to a system for assisting in navigating a medical device (1) in a region of a patient body, such as a cardiac chamber. The system comprises a unit (5) for providing a three-dimensional model of the region and an ultrasound probe (2) for acquiring image signals of the region of the patient body. At least one an ultrasound sensor (6) is attached to the medical device (1) for sensing ultrasound signals emitted by the 5 ultrasound probe (2) and a tracking unit (7) determines a relative position of the at last one ultrasound sensor (6) with respect to the live images and/or the ultrasound probe (2) on the basis of the sensed ultrasound signals. Further, a mapping unit (8) maps the determined relative position of the at least one ultrasound sensor (6) onto the model to generate a visualization of region of the patient body.

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  • INTERVENTIONAL INSTRUMENT COMPRISING AN ULTRASOUND TRANSDUCER

    Toegekend WO2018077909

    The invention relates to an interventional instrument like a catheter comprising an ultrasound unit (41) and a rotation unit (5) for rotating the ultrasound unit, wherein the rotation unit comprises an actuation element (8) being an electroactive polymer or a one-way shape memory alloy for actuating the rotation of the ultrasound unit. Since the rotation unit comprises, as an actuation element for actuating the rotation of the ultrasound unit, an electroactive polymer or a one-way shape memory…

    The invention relates to an interventional instrument like a catheter comprising an ultrasound unit (41) and a rotation unit (5) for rotating the ultrasound unit, wherein the rotation unit comprises an actuation element (8) being an electroactive polymer or a one-way shape memory alloy for actuating the rotation of the ultrasound unit. Since the rotation unit comprises, as an actuation element for actuating the rotation of the ultrasound unit, an electroactive polymer or a one-way shape memory alloy, the rotation unit with the actuation element can be very compact and small.

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  • VISUALIZATION OF AN IMAGE OBJECT RELATING TO AN INSTRUMENT IN AN EXTRACORPOREAL IMAGE

    Toegekend WO2018054796

    The invention relates to an apparatus and a system for visualizing an image object relating to an instrument (3), particularly a medical instrument, in an extracorporeal image. The image object may comprise a representation of the instrument (3) or an intracorporeal image (40) acquired using the instrument (3). The system comprises an extracorporeal image acquisition device (1) for acquiring extracorporeal images with respect to an extracorporeal image frame and a tracking arrangement (2) for…

    The invention relates to an apparatus and a system for visualizing an image object relating to an instrument (3), particularly a medical instrument, in an extracorporeal image. The image object may comprise a representation of the instrument (3) or an intracorporeal image (40) acquired using the instrument (3). The system comprises an extracorporeal image acquisition device (1) for acquiring extracorporeal images with respect to an extracorporeal image frame and a tracking arrangement (2) for tracking the instrument (3) independent of the extracorporeal images with respect to a tracking frame. Further, the invention relates to a method carried out in the system.

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  • ULTRASOUND DEVICE CONTACTING

    Toegekend WO2017186781

    An ultrasound device (10) is disclosed comprising a transducer arrangement (110) and an acoustically transmissive window (150) over said arrangement, said window comprising an elastomer layer (153) having conductive particles dispersed in the elastomer, the elastomer layer having a pressure-sensitive conductivity, the ultrasound device further comprising an electrode arrangement (160) coupled to said elastomer layer and adapted to measure said pressure-sensitive conductivity. An ultrasound…

    An ultrasound device (10) is disclosed comprising a transducer arrangement (110) and an acoustically transmissive window (150) over said arrangement, said window comprising an elastomer layer (153) having conductive particles dispersed in the elastomer, the elastomer layer having a pressure-sensitive conductivity, the ultrasound device further comprising an electrode arrangement (160) coupled to said elastomer layer and adapted to measure said pressure-sensitive conductivity. An ultrasound system and arrangement including such an ultrasound device are also disclosed.

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  • MEDICAL PROBE FOR ULTRASOUND IMAGING

    Toegekend WO2017072098

    An internal probe device for insertion into the body of a patient, comprises an elongate body with a plurality of EAP actuators mounted at the surface of the body. The EAP actuators are made to vibrate so that their position becomes visible in a Doppler ultrasound image. The use of EAP actuators to provide vibrations enables individual locations to be identified. In particular, the movement of the EAP actuator may be largely isolated from the main body of the probe. Furthermore, EAP actuators…

    An internal probe device for insertion into the body of a patient, comprises an elongate body with a plurality of EAP actuators mounted at the surface of the body. The EAP actuators are made to vibrate so that their position becomes visible in a Doppler ultrasound image. The use of EAP actuators to provide vibrations enables individual locations to be identified. In particular, the movement of the EAP actuator may be largely isolated from the main body of the probe. Furthermore, EAP actuators can be thin, lightweight and have a small form factor suitable for application to or within the surface of a probe, such as a catheter, needle or endoscope.

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  • IMPLANTABLE MEDICAL DEVICE AND SYSTEM TO HEAT TISSUE

    Toegekend WO2016202708

    A medical implant device (18) for atrial appendage (20) is presented, suitable to transmit energy to its surrounding. The medical implant device (18) comprising an expandable structure(31,34) and a cover (32) disposed on the expandable structure is adapted toextend across the ostium (21) of the atrial appendage (20) for restricting migration of thrombi from the appendage to the blood stream in the heart (13). The expandable structure (31,34) of the medical implant device (18) configured to…

    A medical implant device (18) for atrial appendage (20) is presented, suitable to transmit energy to its surrounding. The medical implant device (18) comprising an expandable structure(31,34) and a cover (32) disposed on the expandable structure is adapted toextend across the ostium (21) of the atrial appendage (20) for restricting migration of thrombi from the appendage to the blood stream in the heart (13). The expandable structure (31,34) of the medical implant device (18) configured to receive energy from an external energy source (11) is further configured to transmit energy to its surrounding for altering the electrical activation pathways in heart by heating the tissue adjacent to the medical implant device (18).

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  • APPARATUS FOR VISUALIZING TISSUE PROPERTY

    Toegekend WO2016078992

    The present invention relates to an apparatus (1) comprising a signal processor (2) for processing measurement signals (3) from a motion-mode ultrasound measurement and a rendering device (4) coupled to a processor (2) for rendering a one-dimensional representation (40) along a temporal axis (41) indicative of a property within a tissue. The values (42) in the one-dimensional representation (40) are derived on the basis of measured values in an observation window (12, 22, 32) defined on an…

    The present invention relates to an apparatus (1) comprising a signal processor (2) for processing measurement signals (3) from a motion-mode ultrasound measurement and a rendering device (4) coupled to a processor (2) for rendering a one-dimensional representation (40) along a temporal axis (41) indicative of a property within a tissue. The values (42) in the one-dimensional representation (40) are derived on the basis of measured values in an observation window (12, 22, 32) defined on an M-mode ultrasound image (10), a tissue velocity image (20) or a strain rate image (30).

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  • VISUALIZATION APPARATUS FOR PROPERTY CHANGE OF A TISSUE

    Toegekend WO2016079659

    The present invention relates to a visualization apparatus (1) comprising a signal processor (2) for processing measurement signals from an ultrasound measurement (3) and a rendering device (4) coupled to a processor for rendering a representation for discerning a region of tissue with changed property (42) upon energy application to the tissue from a region with unchanged property (41) within two extremities (44,47) of the representation indicative of two boundaries defining the tissue…

    The present invention relates to a visualization apparatus (1) comprising a signal processor (2) for processing measurement signals from an ultrasound measurement (3) and a rendering device (4) coupled to a processor for rendering a representation for discerning a region of tissue with changed property (42) upon energy application to the tissue from a region with unchanged property (41) within two extremities (44,47) of the representation indicative of two boundaries defining the tissue thickness. The rendering of the tissue with changed property (42) and the tissue with unchanged property (41) with different visual aspects is readily absorbable by a person who applies energy to the tissue.

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  • CONTACT DETERMINATION APPARATUS

    Toegekend WO2015166106

    The invention relates to a contact determination apparatus for determining a degree of contact between a device (2) and a moving object (3), wherein the contact determination apparatus comprises a motion distribution providing unit for providing a motion distribution being indicative of motion in the surrounding of the device and a contact determination unit (14) for determining a degree of contact between the device and the object based on the provided motion distribution. Since the degree of…

    The invention relates to a contact determination apparatus for determining a degree of contact between a device (2) and a moving object (3), wherein the contact determination apparatus comprises a motion distribution providing unit for providing a motion distribution being indicative of motion in the surrounding of the device and a contact determination unit (14) for determining a degree of contact between the device and the object based on the provided motion distribution. Since the degree of contact between the device and the object is determined based on the provided motion distribution and not simply based on, for instance, a peak of an A-mode signal, the determination of the degree of contact can be less disturbed by artifacts like ring-down artifacts or by blood scattering, if the object is, for instance, tissue. This can lead to a more accurate determination of the degree of contact.

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  • ULTRASOUND DATA VISUALIZATION APPARATUS

    Toegekend WO2014060870

    The invention relates to an ultrasound data visualization apparatus for visualizing ultrasound data showing an object during an interventional procedure. A reference image (65) and a current image (68) of the object are simultaneously displayed, wherein the current image corresponds to a current time interval and the reference image corresponds to a reference time interval and wherein the current time interval and the reference time interval correspond to different phases of the interventional…

    The invention relates to an ultrasound data visualization apparatus for visualizing ultrasound data showing an object during an interventional procedure. A reference image (65) and a current image (68) of the object are simultaneously displayed, wherein the current image corresponds to a current time interval and the reference image corresponds to a reference time interval and wherein the current time interval and the reference time interval correspond to different phases of the interventional procedure. The current image can be shown therefore with, for instance,a relatively high temporal resolution for allowing a user to observe detailed object changes, which may be caused by the interventional procedure, while an overview over different phases of the interventional procedure can still be provided, because also the reference image is displayed and can be used by a user for comparing the current image with the reference image.

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  • ULTRASOUND DATA VISUALIZATION APPARATUS

    Toegekend WO2014057427

    The invention relates to an ultrasound data visualization apparatus for visualizing ultrasound data, in particular, during a cardiac ablation procedure. An M-mode ultrasound image of an object (23) being preferentially a heart of a person or a feature image of the object comprising features derived from the M-mode ultrasound image and a repetitive signal like an electrocardiography signal being indicative of a repetitive cycle in the image are provided. An image frames determination unit (13)…

    The invention relates to an ultrasound data visualization apparatus for visualizing ultrasound data, in particular, during a cardiac ablation procedure. An M-mode ultrasound image of an object (23) being preferentially a heart of a person or a feature image of the object comprising features derived from the M-mode ultrasound image and a repetitive signal like an electrocardiography signal being indicative of a repetitive cycle in the image are provided. An image frames determination unit (13) determines image frames by temporally segmenting the provided image into image frames corresponding to different repetitive cycles based on the repetitive signal, wherein a display (24) displays the image frames temporally consecutively. Since the display shows these image frames temporally consecutively, a movie-like displaying of the ultrasound data is provided, which allows for a better observation of details and changes of the object, especially of changes in cardiac tissue during an ablation procedure.

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  • DISTRIBUTED SENSING DEVICE FOR REFERENCING OF PHYSIOLOGICAL

    Toegekend WO2013182953

    A distributed sensor and a method for identifying an internal anatomical landmark (R) includes inserting (502) a distributed sensing device (212) into a volume of a body and extending (504) a portion of a length of the distributed sensing device beyond an area of interest. Parameters are measured (506) using sensors (202) located along the length of the distributed sensing device (212), and a transition region is determined (510) based upon a parameter value difference between adjacent sensors.…

    A distributed sensor and a method for identifying an internal anatomical landmark (R) includes inserting (502) a distributed sensing device (212) into a volume of a body and extending (504) a portion of a length of the distributed sensing device beyond an area of interest. Parameters are measured (506) using sensors (202) located along the length of the distributed sensing device (212), and a transition region is determined (510) based upon a parameter value difference between adjacent sensors. A location of an anatomical landmark is assigned (512) using the transition region.

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  • ENERGY APPLICATION APPARATUS

    Toegekend WO2013156896

    The invention relates to an energy application apparatus (1) for applying energy to an object(2). An energy application unit applies energy to the object, wherein the energy application unit is adapted to use electrical current for applying the energy. A current measuring unit(15) measures the electrical current used by the energy application unit and provides a signal being indicative of whether the energy is applied to the object based on the measured electrical current. The signal can be…

    The invention relates to an energy application apparatus (1) for applying energy to an object(2). An energy application unit applies energy to the object, wherein the energy application unit is adapted to use electrical current for applying the energy. A current measuring unit(15) measures the electrical current used by the energy application unit and provides a signal being indicative of whether the energy is applied to the object based on the measured electrical current. The signal can be used by, for instance, a monitoring unit and/or a display unit for using and/or indicating the information whether energy is actually applied or not, without requiring a direct communication between the energy application unit and the monitoring unit and/or the display unit.

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  • IMAGING SYSTEM FOR IMAGING A PERIODICALLY MOVING OBJECT

    Toegekend WO2013140353

    The invention relates to an imaging system for imaging a periodically moving object. An assigning unit (18) assigns ultrasound signals like A-lines to motion phases based on a provided phase signal, wherein an ultrasound images generation unit (19) generates several ultrasound images like gated M-mode images for the different motion phases based on the ultrasound signals assigned to the respective motion phase. A selecting unit (20) is used to select an ultrasound image from the generated…

    The invention relates to an imaging system for imaging a periodically moving object. An assigning unit (18) assigns ultrasound signals like A-lines to motion phases based on a provided phase signal, wherein an ultrasound images generation unit (19) generates several ultrasound images like gated M-mode images for the different motion phases based on the ultrasound signals assigned to the respective motion phase. A selecting unit (20) is used to select an ultrasound image from the generated ultrasound images, wherein a display unit (21) displays the selected ultrasound image. The selected ultrasound image corresponds therefore to a single motion phase only such that motion artifacts in the displayed ultrasound image are reduced. The imaging system is particularly useful for, for instance, monitoring cardiac ablation procedures.

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  • IMAGING SYSTEM FOR IMAGING A PERIODICALLY MOVING OBJECT

    Toegekend WO2013140358

    The invention relates to an imaging system for imaging a periodically moving object. An assigning unit (18) assigns ultrasound signals like A-lines to motion phases based on a provided phase signal,wherein an ultrasound images generation unit (19) generates several ultrasound images like gated M-mode images for the different motion phases based on the ultrasound signals assigned to the respective motion phase. The ultrasound images are temporally consecutively displayed on a display unit (21)…

    The invention relates to an imaging system for imaging a periodically moving object. An assigning unit (18) assigns ultrasound signals like A-lines to motion phases based on a provided phase signal,wherein an ultrasound images generation unit (19) generates several ultrasound images like gated M-mode images for the different motion phases based on the ultrasound signals assigned to the respective motion phase. The ultrasound images are temporally consecutively displayed on a display unit (21) for showing the periodic movement of the object (24).The resulting dynamic, movie-like image of the object allows a user like a physician to more reliably determine properties of the object like a thickness of a tissue wall, in particular, during an ablation procedure. The imaging system is therefore particularly useful for monitoring cardiac ablation procedures.

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  • AN EXAMINATION SYSTEM WITH MULTIPLE ULTRASOUND TRANSDUCERS

    Toegekend WO2013084094

    To sum up, the present invention relates to an examination system 1301 for examining an associated tissue sample 1302, where the examination system comprises an interventional device 1320 which comprises a plurality of ultrasound transducers 306a-c and wherein the different ultrasound transducers are arranged to obtain images of different regions of an associated tissue sample, and wherein the examination system furthermore comprises a display device 1351 arranged for showing the images so that…

    To sum up, the present invention relates to an examination system 1301 for examining an associated tissue sample 1302, where the examination system comprises an interventional device 1320 which comprises a plurality of ultrasound transducers 306a-c and wherein the different ultrasound transducers are arranged to obtain images of different regions of an associated tissue sample, and wherein the examination system furthermore comprises a display device 1351 arranged for showing the images so that each of their positions corresponds to the corresponding positions of the different adjacent tissue sample regions in the adjacent associated tissue sample. A possible advantage of the system may be that relevant information regarding the associated tissue sample is conveyed to an observer in a fast an intuitive manner.

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  • ABLATION APPARATUS

    Toegekend WO2013014583

    The invention relates to an an ablation apparatus for ablating a structure (14) within tissue of a living being. An ultrasound visualization unit (15) generates a two- dimensional or a three-dimensional ultrasound image for finding the structure to be ablated within the tissue. Ablation energy provided by an ablation unit (19) can then accurately be directed to the found structure. Moreover, the ultrasound visualization unit is adapted to generate during the provision of the ablation energy an…

    The invention relates to an an ablation apparatus for ablating a structure (14) within tissue of a living being. An ultrasound visualization unit (15) generates a two- dimensional or a three-dimensional ultrasound image for finding the structure to be ablated within the tissue. Ablation energy provided by an ablation unit (19) can then accurately be directed to the found structure. Moreover, the ultrasound visualization unit is adapted to generate during the provision of the ablation energy an M-mode ultrasound image by sending and receiving ultrasound waves in the direction, in which the structure is located, as found by using the two-dimensional or three-dimensional ultrasound image, thereby monitoring the ablation procedure. This allows for an improved control of the ablation procedure and, thus, for an improved quality of this procedure.

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  • GUIDED DELIVERY OF PROSTHETIC VALVE

    Toegekend WO2012147028

    An image-guided prosthetic valve deployment system employs a prosthetic valve (80), a catheter (70) and a delivery tracking system (90). The catheter (70) has an elongated body with a proximal tip (71a) and a distal tip (71b), and the elongated body includes a delivery section (72) adjacent the distal tip (71b) for deploying the prosthetic valve (80) relative to a heart valve (21) within an anatomical region (20). The delivery section (72) includes a delivery segment (73) for sensing a shape…

    An image-guided prosthetic valve deployment system employs a prosthetic valve (80), a catheter (70) and a delivery tracking system (90). The catheter (70) has an elongated body with a proximal tip (71a) and a distal tip (71b), and the elongated body includes a delivery section (72) adjacent the distal tip (71b) for deploying the prosthetic valve (80) relative to a heart valve (21) within an anatomical region (20). The delivery section (72) includes a delivery segment (73) for sensing a shape and an orientation of the delivery section (72) within the anatomical region (20) relative to a reference point (74). The delivery tracking system (90) tracks a position and an orientation of the prosthetic valve (80) relative to the heart valve (21) as a function of a sensed shape and a sensed orientation of the delivery section (72) within the anatomical region (20) relative to the reference point (74) by the delivery segment (73).

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  • APPARATUS FOR BEING USED FOR DETECTING A PROPERTY OF AN OBJECT

    Toegekend WO2012066455

    The invention relates to an apparatus for being used for detecting a property of an object. An ultrasound signal providing unit (2) provides an ultrasound signal, which is indicative of a property of the object (9) at oneor several depths within the object (9) and which depends on time, and a periodicity value determination unit (5) determines a periodicityvalue being indicative of a degree of temporal periodicityofthe ultrasound signal for a constant depth. The temporalperiodicityofthe…

    The invention relates to an apparatus for being used for detecting a property of an object. An ultrasound signal providing unit (2) provides an ultrasound signal, which is indicative of a property of the object (9) at oneor several depths within the object (9) and which depends on time, and a periodicity value determination unit (5) determines a periodicityvalue being indicative of a degree of temporal periodicityofthe ultrasound signal for a constant depth. The temporalperiodicityofthe ultrasound signalat the respective constant depth, i.e. the periodicity value, depends on the property of the object at this depth and can therefore be used for detecting a property of the object.

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  • FILTERING APPARATUS FOR FILTERING AN ULTRASOUND SIGNAL

    Toegekend WO2012066462

    The invention relates to a filtering apparatus (15) for filtering an ultrasound signal, which is influenced by an electrical unit and comprises a first part including information about an object (4) from which the ultrasound signal has been received and a second part not comprising information about the object. A correction signal determination unit (17) determines a correction signal being indicative of the influence of the electrical unit on the ultrasound signal from the second part of the…

    The invention relates to a filtering apparatus (15) for filtering an ultrasound signal, which is influenced by an electrical unit and comprises a first part including information about an object (4) from which the ultrasound signal has been received and a second part not comprising information about the object. A correction signal determination unit (17) determines a correction signal being indicative of the influence of the electrical unit on the ultrasound signal from the second part of the ultrasound signal and a correction unit (18) corrects the first part of the ultrasound signal based on the determined correction signal for filtering the influence of the electrical unit out of the ultrasound signal. Since the correction signal is indicative of the influence of the electrical unit, wherein the correction signal is used for correcting the ultrasound signal, unwanted interference visible in the unfiltered ultrasound signal can be filtered out.

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  • LOCATION DETERMINATION APPARATUS

    Toegekend WO2012066437

    The invention relates to location determination apparatus for determining a location of a first object (2) like a catheter within a second object (3) being, for example, the heart of a person. The first object comprises a first ultrasound unit, and a second ultrasound unit (5) is located outside the second object. A location determination unit determines the location of the first object within the second object based on ultrasound signals transmitted 5 between the first ultrasound unit and the…

    The invention relates to location determination apparatus for determining a location of a first object (2) like a catheter within a second object (3) being, for example, the heart of a person. The first object comprises a first ultrasound unit, and a second ultrasound unit (5) is located outside the second object. A location determination unit determines the location of the first object within the second object based on ultrasound signals transmitted 5 between the first ultrasound unit and the second ultrasound unit. This allows determining the location of the first object within the second object reliably in a way which is an alternative to using a transmission of electrical signals for determining the location and which may lead to an improved accuracy of determining the location.

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  • PROPERTY DETERMINATION APPARATUS FOR DETERMINING A PROPERTY OF AN OBJECT

    Toegekend WO2012049621

    The invention relates to a property determination apparatus (1) for determining a property of an object (3). Optical sensing data being indicative of an optical property of the object and ultrasound sensing data being indicative of an ultrasound property of the object are generated, and a property determination unit (75) determines a property of the object based on at least one of the optical sensing data and the ultrasound sensing data. Since light and ultrasound have generally different…

    The invention relates to a property determination apparatus (1) for determining a property of an object (3). Optical sensing data being indicative of an optical property of the object and ultrasound sensing data being indicative of an ultrasound property of the object are generated, and a property determination unit (75) determines a property of the object based on at least one of the optical sensing data and the ultrasound sensing data. Since light and ultrasound have generally different penetration depths and scattering properties with respect to the object, a property of the object can be determined with good quality, even if the quality of one of the optical sensing data and the ultrasound sensing data is reduced by, for example, a relatively small penetration depth, or if one of the optical sensing data and the ultrasound sensing data is less suitable for determining a desired property of the object.

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  • ENERGY APPLICATION APPARATUS FOR APPLYING ENERGY TO AN OBJECT

    Toegekend WO2012001595

    The invention relates to an energy application apparatus for applying energy to an object. A plurality of energy application elements (4) applies energy to the object at different locations and at least one ultrasound element (18) generates an ultrasound signal being indicative of a property of the object at the different locations, wherein at least one energy application element is individually controlled depending on an energy application influence, in particular, an ablation depth…

    The invention relates to an energy application apparatus for applying energy to an object. A plurality of energy application elements (4) applies energy to the object at different locations and at least one ultrasound element (18) generates an ultrasound signal being indicative of a property of the object at the different locations, wherein at least one energy application element is individually controlled depending on an energy application influence, in particular, an ablation depth, determined for the location at which the at least one energy application element applies energy from the ultrasound signal. Thus, at least one local control point for applying energy to the object is provided, thereby improving the control of applying energy to the object.

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  • PROPERTY DETERMINING APPARATUS FOR DETERMINING A PROPERTY OF AN OBJECT

    Toegekend WO2011135482

    The invention relates to a property determining apparatus for determining a property of an object, which is preferentially a heart. An ultrasound signal providing unit provides an ultrasound signal of the object and a scatter determination unit (8) determines at least one scatter value being indicative of a scatter of the ultrasound pulse by a fluid perfusing the object depending on the ultrasound signal. A property determination unit (15) determines a property of the object depending on the at…

    The invention relates to a property determining apparatus for determining a property of an object, which is preferentially a heart. An ultrasound signal providing unit provides an ultrasound signal of the object and a scatter determination unit (8) determines at least one scatter value being indicative of a scatter of the ultrasound pulse by a fluid perfusing the object depending on the ultrasound signal. A property determination unit (15) determines a property of the object depending on the at least one scatter value. In contrast to tissue damage detection methods based on bubble formation, an object property related to perfusion, like whether tissue is ablated or non-ablated, can relatively directly be determined based on the scatter of the ultrasound pulse by the fluid, thereby increasing the accuracy of determining a property of the object.

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  • ABLATION CATHETER AND A METHOD OF PERFORMING ABLATION

    Toegekend WO2011101778

    The invention relates to an ablation catheter, for performing ablation of a target tissue in a patient, where the ablation catheter comprises an elongate body part with a distal end, and an ablation electrode with a distal part. A tissue abutment part extends to a location distal of the ablation electrode distal part in order to separate the distal part of the ablation electrode spatially from the target tissue. This allows of more efficient irrigation and cooling of the target tissue site and…

    The invention relates to an ablation catheter, for performing ablation of a target tissue in a patient, where the ablation catheter comprises an elongate body part with a distal end, and an ablation electrode with a distal part. A tissue abutment part extends to a location distal of the ablation electrode distal part in order to separate the distal part of the ablation electrode spatially from the target tissue. This allows of more efficient irrigation and cooling of the target tissue site and of the ablation electrode, and further allows direct monitoring of the target tissue, e.g. by an ultrasound transducer.

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  • COMBINED ABLATION AND ULTRASOUND IMAGING

    Toegekend WO2011095937

    The present invention relates to a system (100) for combined ablation and ultrasound imaging of associated tissue (40), which is particularly useful for use in an ablation process. The system comprises an interventional device (20) with an ultrasound transducer and an ablation unit. During an ablation process, the interventional device (20) can be applied for both ablation and imaging of the tissue (40) subject to the ablation. A controlling unit (CTRL) is further comprised within the system…

    The present invention relates to a system (100) for combined ablation and ultrasound imaging of associated tissue (40), which is particularly useful for use in an ablation process. The system comprises an interventional device (20) with an ultrasound transducer and an ablation unit. During an ablation process, the interventional device (20) can be applied for both ablation and imaging of the tissue (40) subject to the ablation. A controlling unit (CTRL) is further comprised within the system, and arranged to calculate a predictor value based on one or more signals from the ultrasound transducer, where the predictor value relates to a risk of impending tissue damage due to a rapid release of bubble energy. According to a specific embodiment, a primary signal is sent if the predictor value exceeds a threshold value, so that proper measures can be taken.

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  • MEDICAL ULTRASOUND DEVICE WITH FORCE DETECTION

    Toegekend WO2011033421

    A medical ultrasound device is disclosed. The device comprises an elongated body having a proximal end and a distal end region (1). One or more ultrasound transducers (4) for generating acoustic radiation are positioned in the distal end region, inside the elongated body. A transmission element (5) which is substantially transparent to acoustic radiation is positioned in the radiation path of the acoustic radiation, and a controller unit is operatively connected to the ultrasound transducer…

    A medical ultrasound device is disclosed. The device comprises an elongated body having a proximal end and a distal end region (1). One or more ultrasound transducers (4) for generating acoustic radiation are positioned in the distal end region, inside the elongated body. A transmission element (5) which is substantially transparent to acoustic radiation is positioned in the radiation path of the acoustic radiation, and a controller unit is operatively connected to the ultrasound transducer. The transmission element and the one or more ultrasound transducers are mounted so that an acoustic path length (8) between the transmission element (5) and the ultrasound transducer (4) varies with contact force (10) imposed to the distal end region. The controller unit detects the acoustic path length between the ultrasound transducer and the transmission element and determines the contact force from the detected acoustic path length. In an embodiment, the medical device is an ultrasound RF ablation catheter.

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  • A CATHETER FOR OPEN-LOOP IRRIGATED ABLATION OF TISSUE

    Toegekend WO2011024133

    The present invention relates to a catheter (20) adapted for open-loop irrigated ablation, such as RF ablation, of a tissue (40). Said catheter has a distal tip (22) with an ablation entity (15) adapted for performing ablation of the tissue, an irrigation hole (21) and an ultrasound transducer (5) adapted for transmitting and/or receiving ultrasonic waves. The ultrasound transducer is disposed behind or in the irrigation hole of the catheter, so as to allow an irrigation fluid to flow out of…

    The present invention relates to a catheter (20) adapted for open-loop irrigated ablation, such as RF ablation, of a tissue (40). Said catheter has a distal tip (22) with an ablation entity (15) adapted for performing ablation of the tissue, an irrigation hole (21) and an ultrasound transducer (5) adapted for transmitting and/or receiving ultrasonic waves. The ultrasound transducer is disposed behind or in the irrigation hole of the catheter, so as to allow an irrigation fluid to flow out of the irrigation hole, and so as to allow transmitting and/or receiving the ultrasonic waves through the irrigation hole. The invention also relates to an imaging system and to a corresponding method for operating a catheter.

    Patent weergeven
  • VISUALIZATION APPARATUS

    Toegekend WO2010140069

    The invention relates to a visualization apparatus for visualizing aquality of applying energy to an object. The quality of applying energy at a location on the object (3) is visualized based on a) a provided image of the object and b) a provided quality value representing the quality of applying energy to the object at the location on the object (3), wherein a visual property assigning unit (9) assigns a visual property to the location depending on the quality value and a display(10) displays…

    The invention relates to a visualization apparatus for visualizing aquality of applying energy to an object. The quality of applying energy at a location on the object (3) is visualized based on a) a provided image of the object and b) a provided quality value representing the quality of applying energy to the object at the location on the object (3), wherein a visual property assigning unit (9) assigns a visual property to the location depending on the quality value and a display(10) displays the provided image and the assigned visual property at the location on the object shown in the image.In general a person who applies energy to the object is focused on the location at which energy is applied. Since quality information is shown at the location on which the person is already focused, the quality dependent information can easily be absorbed by the person.

    Patent weergeven
  • APPARATUS, METHOD AND COMPUTER PROGRAM FOR DETERMINING A PROPERTY OF A HEART

    Toegekend WO2010131178

    The present invention relates to an apparatus for determining a property of a heart. The apparatus comprises a catheter (5), which comprises a first property sensing unit for sensing a contraction signal indicative of a reoccurring local contraction of the heart (2) at a sensing site of the heart (2). The apparatus further comprises a first property determining unit (8) for determining the reoccurring local contraction of the heart (2) at the sensing site from the sensed contraction signal as a…

    The present invention relates to an apparatus for determining a property of a heart. The apparatus comprises a catheter (5), which comprises a first property sensing unit for sensing a contraction signal indicative of a reoccurring local contraction of the heart (2) at a sensing site of the heart (2). The apparatus further comprises a first property determining unit (8) for determining the reoccurring local contraction of the heart (2) at the sensing site from the sensed contraction signal as a first property of the heart (2). The reoccurring local contraction provides information about the heart (2), which can be used for a better and/or more reliable characterization of the heart (2).

    Patent weergeven
  • MONITORING APPARATUS FOR MONITORING AN ABLATION PROCEDURE

    Toegekend WO2010082146

    The present invention relates to a monitoring apparatus(101) for monitoring an ablation procedure. The monitoring apparatus (101) comprises an ultrasound signal providing unit for providing an ultrasound signal that depends on received echo series of an object (4) that is ablated. The monitoring apparatus (101) further comprises an ablation depth determination unit (103) for determining an ablation depth from the provided ultrasound signal. The ablation depth can be determined directly from the…

    The present invention relates to a monitoring apparatus(101) for monitoring an ablation procedure. The monitoring apparatus (101) comprises an ultrasound signal providing unit for providing an ultrasound signal that depends on received echo series of an object (4) that is ablated. The monitoring apparatus (101) further comprises an ablation depth determination unit (103) for determining an ablation depth from the provided ultrasound signal. The ablation depth can be determined directly from the ultrasound signal and is an important parameter while performing an ablation procedure. For example, it can be used for determining the progress of ablation within the object (4) and for determining when the ablation has reached a desired progression.

    Patent weergeven
  • ACOUSTICAL SWITCH AND CATHETER COMPRISING ACOUSTICAL SWITCH

    Toegekend WO2010055443

    The invention relates to an acoustical switch wherein the idea to the ultrasound propagation direction may be changes without moving the switch. The switch device comprises two sheets of acoustically transparent material. The sheets constitute opposite walls of a housing. The switch device further comprises one or more orifices for allowing conduction of fluid into and/or out of said housing. The switch device may be made reflective by filling the housing with a gas via the one or more…

    The invention relates to an acoustical switch wherein the idea to the ultrasound propagation direction may be changes without moving the switch. The switch device comprises two sheets of acoustically transparent material. The sheets constitute opposite walls of a housing. The switch device further comprises one or more orifices for allowing conduction of fluid into and/or out of said housing. The switch device may be made reflective by filling the housing with a gas via the one or more orifices. Moreover, the switch device may be made transmissive to ultrasound by filling the housing with a liquid via the one or more orifices and/or by subjecting the housing to underpressure via the one or more orifices. The acoustical switch device fits well within a catheter, which has severe dimensional limitations.

    Patent weergeven

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