The Experts below are selected from a list of 27654 Experts worldwide ranked by ideXlab platform
Stephan B Felix - One of the best experts on this subject based on the ideXlab platform.
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cutting balloon angioplasty effectively facilitates the Interventional Procedure and leads to a low rate of recurrent stenosis in ostial bifurcation coronary lesions a subgroup analysis of the nicecut multicenter registry
International Journal of Cardiology, 2008Co-Authors: Johannes B Dahm, Marcus Dorr, Elisabeth Scholz, Jorg Ruppert, Astrid Hummel, Alexander Staudt, Stephan B FelixAbstract:Abstract Background Displacement of plaque is a major concern during coronary intervention of ostial bifurcation lesions. For this reason, angioplasty involves complex stenting Procedures, which may trigger development of restenosis in a previously non-diseased parent vessel. Objectives To examine, whether plaque displacement may be prevented by scoring atherosclerotic plaque with a cutting-balloon (CB) stand-alone Procedure. Methods Data of patients with Duke E and B type ostial bifurcation lesions (≥70% stenosis involving a diagonal and/or marginal branch >2 mm deriving from a non-diseased parent vessel), who were treated with CB as stand-alone Procedure within the prospective NICECUT multicenter trial were analyzed. Primary endpoint was the rate of binary stenosis and target lesion revascularization (TLR). Secondary endpoints were procedural success and major adverse cardiac events (MACE) at 6-months follow-up. Results 63 out of 65 lesions (56 patients) were successfully amenable to treatment with CB (96.4% procedural success). 76.9% of patients were successfully treated with CB as a stand-alone Procedure, while provisional stenting was necessary in 23.1%. At follow-up, binary stenosis was found in 23.2%, among the total population. Total rate of TLR and MACE were 7.7% and 3.6%, respectively, compared to 4.0% and 2.0% in patients for whom CB stand-alone Procedure was feasible, while it was 20.0% and 6.7% for stented lesions. Conclusions CB angioplasty as a stand-alone Procedure may facilitate Interventional treatment of ostial bifurcation lesions and may help to avoid complex stenting Procedures. It is associated with a low rate of binary stenosis and TLR.
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directional atherectomy facilitates the Interventional Procedure and leads to a low rate of recurrent stenosis in left anterior descending and left circumflex artery ostium stenoses subgroup analysis of the flexi cut study
Heart, 2006Co-Authors: Johannes B Dahm, Astrid Hummel, Joerg Ruppert, Stefanie Hartmann, Dirk Vogelgesang, Stephan B FelixAbstract:Objectives: To examine by retrospective analysis of data from the FLEXI -CUT monocentre registry whether atherectomy can effectively simplify complex stent implantation in ostial bifurcation lesions by reducing the Procedure to stenting of the left anterior descending (LAD) or left circumflex (LCX) artery ostium alone. Patients and methods: All patients who had been enrolled in the prospective FLEXI -CUT study (directional atherectomy with adjunctive balloon angioplasty) were retrospectively analysed on the basis of significant LAD or LCX ostial stenosis (⩾ 70% stenosis) deriving from an undiseased left main stem. The primary combined end point was the rate of target lesion revascularisation (TLR) and binary restenosis; secondary end points were procedural success and major adverse cardiac events (MACE) at the six-month follow up. Results: Of 30 patients enrolled with significant LAD or LCX ostium stenosis, 29 were effectively treated with directional atherectomy (96.7% procedural success). All patients underwent single-vessel stenting Procedures of solely the LAD or LCX ostium. At follow up, binary stenosis was 25% (6 of 24), TLR (angiographic plus clinical) 10.3% (3 of 29) and total MACE 6.9% (2 of 29). Conclusions: Directional atherectomy with single-vessel stenting Procedures facilitates the Interventional treatment of LAD and LCX ostium stenosis, and leads to remarkably low TLR and binary stenosis at follow up.
Iulian Iordachita - One of the best experts on this subject based on the ideXlab platform.
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development and evaluation of an actuated mri compatible robotic system for mri guided prostate intervention
IEEE-ASME Transactions on Mechatronics, 2013Co-Authors: Axel Krieger, Sang-eun Song, Gabor Fichtinger, Iulian Iordachita, Peter Guion, Louis L WhitcombAbstract:This paper reports the design, development, and magnetic resonance imaging (MRI) compatibility evaluation of an actuated transrectal prostate robot for MRI-guided needle intervention in the prostate. The robot performs actuated needle MRI guidance with the goals of providing 1) MRI compatibility; 2) MRI-guided needle placement with accuracy sufficient for targeting clinically significant prostate cancer foci; 3) reducing Interventional Procedure times (thus increasing patient comfort and reducing opportunity for needle targeting error due to patient motion); 4) enabling real-time MRI monitoring of Interventional Procedures; and 5) reducing the opportunities for error that arise in manually actuated needle placement. The design of the robot, employing piezoceramic-motor actuated needle guide positioning and manual needle insertion, is reported. Results of an MRI compatibility study show no reduction of MRI signal-to-noise ratio (SNR) with the disabled motors. Enabling the motors reduces the SNR by 80% without radio frequency (RF) shielding, but the SNR is only reduced by 40-60% with RF shielding. The addition of RF shielding is shown to significantly reduce image SNR degradation caused by the presence of the robotic device. An accuracy study of MRI-guided biopsy needle placements in a prostate phantom is reported. The study shows an average in-plane targeting error of 2.4 mm with a maximum error of 3.7 mm. These data indicate that the system's needle targeting accuracy is similar to that obtained with a previously reported manually actuated system, and is sufficient to reliably sample clinically significant prostate cancer foci under MRI guidance.
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Preliminary evaluation of a MRI-compatible modular robotic system for MRI-guided prostate interventions
2010 3rd IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics, 2010Co-Authors: Sang-eun Song, Junichi Tokuda, Nobuhiko Hata, Clare Tempany, Gabor Fichtinger, Iulian IordachitaAbstract:Magnetic Resonance Imaging (MRI) guided robotic interventions have been introduced in order to advance prostate cancer detection and treatment. To overcome problems of such robotic interventions, we have been developing a pneumatically actuated MRI-compatible modular robotic system for MRI-guided transperineal prostate intervention and its Interventional Procedure. For system evaluation, a series of experiments have been conducted and this paper reports a needle insertion experiment using prostate phantom and patient mockup trials. The needle insertion experiment resulted in noticeable consistent error in one direction, which we will investigate further. Nonetheless, patient mockup experiences suggest that the modular robotic system and its Interventional Procedure are well integrated and implemented in clinical environment.
Johannes B Dahm - One of the best experts on this subject based on the ideXlab platform.
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cutting balloon angioplasty effectively facilitates the Interventional Procedure and leads to a low rate of recurrent stenosis in ostial bifurcation coronary lesions a subgroup analysis of the nicecut multicenter registry
International Journal of Cardiology, 2008Co-Authors: Johannes B Dahm, Marcus Dorr, Elisabeth Scholz, Jorg Ruppert, Astrid Hummel, Alexander Staudt, Stephan B FelixAbstract:Abstract Background Displacement of plaque is a major concern during coronary intervention of ostial bifurcation lesions. For this reason, angioplasty involves complex stenting Procedures, which may trigger development of restenosis in a previously non-diseased parent vessel. Objectives To examine, whether plaque displacement may be prevented by scoring atherosclerotic plaque with a cutting-balloon (CB) stand-alone Procedure. Methods Data of patients with Duke E and B type ostial bifurcation lesions (≥70% stenosis involving a diagonal and/or marginal branch >2 mm deriving from a non-diseased parent vessel), who were treated with CB as stand-alone Procedure within the prospective NICECUT multicenter trial were analyzed. Primary endpoint was the rate of binary stenosis and target lesion revascularization (TLR). Secondary endpoints were procedural success and major adverse cardiac events (MACE) at 6-months follow-up. Results 63 out of 65 lesions (56 patients) were successfully amenable to treatment with CB (96.4% procedural success). 76.9% of patients were successfully treated with CB as a stand-alone Procedure, while provisional stenting was necessary in 23.1%. At follow-up, binary stenosis was found in 23.2%, among the total population. Total rate of TLR and MACE were 7.7% and 3.6%, respectively, compared to 4.0% and 2.0% in patients for whom CB stand-alone Procedure was feasible, while it was 20.0% and 6.7% for stented lesions. Conclusions CB angioplasty as a stand-alone Procedure may facilitate Interventional treatment of ostial bifurcation lesions and may help to avoid complex stenting Procedures. It is associated with a low rate of binary stenosis and TLR.
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directional atherectomy facilitates the Interventional Procedure and leads to a low rate of recurrent stenosis in left anterior descending and left circumflex artery ostium stenoses subgroup analysis of the flexi cut study
Heart, 2006Co-Authors: Johannes B Dahm, Astrid Hummel, Joerg Ruppert, Stefanie Hartmann, Dirk Vogelgesang, Stephan B FelixAbstract:Objectives: To examine by retrospective analysis of data from the FLEXI -CUT monocentre registry whether atherectomy can effectively simplify complex stent implantation in ostial bifurcation lesions by reducing the Procedure to stenting of the left anterior descending (LAD) or left circumflex (LCX) artery ostium alone. Patients and methods: All patients who had been enrolled in the prospective FLEXI -CUT study (directional atherectomy with adjunctive balloon angioplasty) were retrospectively analysed on the basis of significant LAD or LCX ostial stenosis (⩾ 70% stenosis) deriving from an undiseased left main stem. The primary combined end point was the rate of target lesion revascularisation (TLR) and binary restenosis; secondary end points were procedural success and major adverse cardiac events (MACE) at the six-month follow up. Results: Of 30 patients enrolled with significant LAD or LCX ostium stenosis, 29 were effectively treated with directional atherectomy (96.7% procedural success). All patients underwent single-vessel stenting Procedures of solely the LAD or LCX ostium. At follow up, binary stenosis was 25% (6 of 24), TLR (angiographic plus clinical) 10.3% (3 of 29) and total MACE 6.9% (2 of 29). Conclusions: Directional atherectomy with single-vessel stenting Procedures facilitates the Interventional treatment of LAD and LCX ostium stenosis, and leads to remarkably low TLR and binary stenosis at follow up.
Sang-eun Song - One of the best experts on this subject based on the ideXlab platform.
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development and evaluation of an actuated mri compatible robotic system for mri guided prostate intervention
IEEE-ASME Transactions on Mechatronics, 2013Co-Authors: Axel Krieger, Sang-eun Song, Gabor Fichtinger, Iulian Iordachita, Peter Guion, Louis L WhitcombAbstract:This paper reports the design, development, and magnetic resonance imaging (MRI) compatibility evaluation of an actuated transrectal prostate robot for MRI-guided needle intervention in the prostate. The robot performs actuated needle MRI guidance with the goals of providing 1) MRI compatibility; 2) MRI-guided needle placement with accuracy sufficient for targeting clinically significant prostate cancer foci; 3) reducing Interventional Procedure times (thus increasing patient comfort and reducing opportunity for needle targeting error due to patient motion); 4) enabling real-time MRI monitoring of Interventional Procedures; and 5) reducing the opportunities for error that arise in manually actuated needle placement. The design of the robot, employing piezoceramic-motor actuated needle guide positioning and manual needle insertion, is reported. Results of an MRI compatibility study show no reduction of MRI signal-to-noise ratio (SNR) with the disabled motors. Enabling the motors reduces the SNR by 80% without radio frequency (RF) shielding, but the SNR is only reduced by 40-60% with RF shielding. The addition of RF shielding is shown to significantly reduce image SNR degradation caused by the presence of the robotic device. An accuracy study of MRI-guided biopsy needle placements in a prostate phantom is reported. The study shows an average in-plane targeting error of 2.4 mm with a maximum error of 3.7 mm. These data indicate that the system's needle targeting accuracy is similar to that obtained with a previously reported manually actuated system, and is sufficient to reliably sample clinically significant prostate cancer foci under MRI guidance.
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Preliminary evaluation of a MRI-compatible modular robotic system for MRI-guided prostate interventions
2010 3rd IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics, 2010Co-Authors: Sang-eun Song, Junichi Tokuda, Nobuhiko Hata, Clare Tempany, Gabor Fichtinger, Iulian IordachitaAbstract:Magnetic Resonance Imaging (MRI) guided robotic interventions have been introduced in order to advance prostate cancer detection and treatment. To overcome problems of such robotic interventions, we have been developing a pneumatically actuated MRI-compatible modular robotic system for MRI-guided transperineal prostate intervention and its Interventional Procedure. For system evaluation, a series of experiments have been conducted and this paper reports a needle insertion experiment using prostate phantom and patient mockup trials. The needle insertion experiment resulted in noticeable consistent error in one direction, which we will investigate further. Nonetheless, patient mockup experiences suggest that the modular robotic system and its Interventional Procedure are well integrated and implemented in clinical environment.
Nobuhiko Hata - One of the best experts on this subject based on the ideXlab platform.
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Preliminary evaluation of a MRI-compatible modular robotic system for MRI-guided prostate interventions
2010 3rd IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics, 2010Co-Authors: Sang-eun Song, Junichi Tokuda, Nobuhiko Hata, Clare Tempany, Gabor Fichtinger, Iulian IordachitaAbstract:Magnetic Resonance Imaging (MRI) guided robotic interventions have been introduced in order to advance prostate cancer detection and treatment. To overcome problems of such robotic interventions, we have been developing a pneumatically actuated MRI-compatible modular robotic system for MRI-guided transperineal prostate intervention and its Interventional Procedure. For system evaluation, a series of experiments have been conducted and this paper reports a needle insertion experiment using prostate phantom and patient mockup trials. The needle insertion experiment resulted in noticeable consistent error in one direction, which we will investigate further. Nonetheless, patient mockup experiences suggest that the modular robotic system and its Interventional Procedure are well integrated and implemented in clinical environment.
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real time magnetic resonance imaging driven by electromagnetic locator for Interventional Procedure and endoscopic therapy
Surgical Endoscopy and Other Interventional Techniques, 2008Co-Authors: Jaesung Hong, Nobuhiko Hata, Kozo Konishi, Makoto HashizumeAbstract:Background Surgical navigation systems using an optical position sensor have the occlusion problem due to a person or instrument in the line of sight of the camera. In this study, occlusion-free real-time magnetic resonance (MR) scanning with a passive electromagnetic locator is proposed. Methods A newly developed converter transforms the data of an electromagnetic locator into that of an optical sensor. Registration between the two different coordinate systems is performed for the electromagnetic locator to substitute the optical sensor without modifying the MRI system. Results An oil marker attached to the electromagnetic locator was identified in real-time MR images. Preliminary results demonstrated the high usability of the electromagnetic locator as an alternative position tracking method in the MR gantry. Conclusions The occlusion problem of optical sensors is resolved by the proposed method.
