Gotowe bibliografie tematyczne / Catheter tip contact force

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Gotowa bibliografia na temat „Catheter tip contact force”

Autor: Grafiati

Data publikacji: 6 września 2023

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Artykuły w czasopismach na temat "Catheter tip contact force"

Shah, Dipen. "Evolution of Force Sensing Technologies". Arrhythmia & Electrophysiology Review 6, nr 2 (2017): 75. http://dx.doi.org/10.15420/aer.2017.8.2.

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In order to improve the procedural success and long-term outcomes of catheter ablation techniques for atrial fibrillation (AF), an important unfulfilled requirement is to create durable electrophysiologically complete lesions. Measurement of contact force (CF) between the catheter tip and the target tissue can guide physicians to optimise both mapping and ablation procedures. Contact force can affect lesion size and clinical outcomes following catheter ablation of AF. Force sensing technologies have matured since their advent several years ago, and now allow the direct measurement of CF between the catheter tip and the target myocardium in real time. In order to obtain complete durable lesions, catheter tip spatial stability and stable contact force are important. Suboptimal energy delivery, lesion density/contiguity and/or excessive wall thickness of the pulmonary vein-left atrial (PV-LA) junction may result in conduction recovery at these sites. Lesion assessment tools may help predict and localise electrical weak points resulting in conduction recovery during and after ablation. There is increasing clinical evidence to show that optimal use of CF sensing during ablation can reduce acute PV re-conduction, although prospective randomised studies are desirable to confirm long-term favourable clinical outcomes. In combination with optimised lesion assessment tools, contact force sensing technology has the potential to become the standard of care for all patients undergoing AF catheter ablation.

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Shah, Dipen. "Evolution of Force Sensing Technologies". Arrhythmia & Electrophysiology Review 6, nr 2 (2017): 75. http://dx.doi.org/10.15420/aer.2017:8:2.

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Bickel, Karen, Thorsten Lewalter, Johannes Fischer, Christine Baumgartner, Petra Hoppmann, Klaus Tiemann i Clemens Jilek. "Value of Mini Electrodes for Mapping Myocardial Arrhythmogenic Substrate—The Influence of Tip-to-Tissue Angulation and Irrigation Flow on Signal Quality". Journal of Vascular Diseases 1, nr 1 (3.08.2022): 3–12. http://dx.doi.org/10.3390/jvd1010002.

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Background: The use of mini electrodes with a small surface and narrow electrode-to-electrode spacing is believed to lead to a higher electrical resolution. Until now, the effects of tip-to-tissue contact, angulation, and irrigation on signal quality and morphology are unknown. Methods: The beating heart of an open-chest pig was examined while controlling the angulation and contact between the catheter tip and myocardial tissue, as well as the irrigation of the catheter tip. The mini electrodes were mounted onto commercially available 8 mm non-irrigated and 4 mm irrigated tip catheters. Different electrode interconnections, angulations, contact forces, and irrigation flow were analyzed and compared to signals recorded from conventional electrodes. Results: A total of 63 electrode samples of 21 defined, stable settings, each lasting 30 s, were analyzed. (1) Tissue contact of mini electrodes was given as soon as the conventional tip electrode showed tissue contact. (2) Angulation of the tip-to-tissue contact showed a trend towards changes in the integral of signals derived from mini electrodes, and no significant changes were seen in signals derived from conventional or mini electrodes. (3) Irrigation flow surrounding the mini electrodes did not influence signals derived from mini electrodes, whereas conventional electrodes showed signals with a longer duration under higher irrigation. Conclusion: Mini electrodes are robust to contact force and irrigation flow regarding signal quality, whereas signals of conventional electrodes are affected by irrigation flow, leading to substantial changes in signal duration and kurtosis. Signals of mini electrodes are sensitive to local electrical changes because of a high local resolution.

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Page, Stephen P., i Mehul Dhinoja. "SmartTouch™ – The Emerging Role of Contact Force Technology in Complex Catheter Ablation". Arrhythmia & Electrophysiology Review 1 (2012): 59. http://dx.doi.org/10.15420/aer.2012.1.59.

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Novel technologies have been developed recently to assess contact between the ablation catheter and the underlying tissue in an attempt to improve safe and effective lesion delivery. The most recently developed technology is the SmartTouch™ catheter which is an open irrigated-tip catheter integrated within the CARTO 3 3D mapping system. In this review we consider the role of contact force technology, evaluate the published data and discuss the potential applications of this novel technology.

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Deubner, N., H. Greiss, E. Akkaya, A. Berkowitsch, S. Zaltsberg, C. W. Hamm, M. Kuniss i T. Neumann. "Clinical experience with contact-force and flexible-tip ablation catheter designs". Journal of Interventional Cardiac Electrophysiology 47, nr 1 (31.03.2016): 75–82. http://dx.doi.org/10.1007/s10840-016-0128-3.

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Karkowski, Grzegorz, Marcin Kuniewicz, Andrzej Ząbek, Edward Koźluk, Maciej Dębski, Paweł T. Matusik i Jacek Lelakowski. "Contact Force-Sensing versus Standard Catheters in Non-Fluoroscopic Radiofrequency Catheter Ablation of Idiopathic Outflow Tract Ventricular Arrhythmias". Journal of Clinical Medicine 11, nr 3 (25.01.2022): 593. http://dx.doi.org/10.3390/jcm11030593.

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Background: Adequate contact between the catheter tip and tissue is important for optimal lesion formation and, in some procedures, it has been associated with improved effectiveness and safety. We evaluated the potential benefits of contact force-sensing (CFS) catheters during non-fluoroscopic radiofrequency catheter ablation (NF-RFCA) of idiopathic ventricular arrhythmias (VAs) originating from outflow tracts (OTs). Methods: A group of 102 patients who underwent NF-RFCA (CARTO, Biosense Webster Inc., Irvine, CA, USA) of VAs from OTs between 2014 to 2018 was retrospectively analyzed. Results: We included 52 (50.9%) patients in whom NF-RFCA was performed using CFS catheters and 50 (49.1%) who were ablated using standard catheters. Arrhythmias were localized in the right and left OT in 70 (68.6%) and 32 (31.4%) patients, respectively. The RFCA acute success rate was 96.1% (n = 98) and long-term success during a minimum 12-month follow-up (mean 51.3 ± 21.6 months) was 85.3% (n = 87), with no difference between CFS and standard catheters. There was no difference in complications rate between CFS (n = 1) and standard catheter (n = 2) ablations. Conclusions: There is no additional advantage of CFS catheters use over standard catheters during NF-RFCA of OT-VAs in terms of procedural effectiveness and safety.

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Paulsen, Benjamin Alexander, Hannes Schwenke, Jakob Seemann, Peter Schramm, Georg Männel i Philipp Rostalski. "Towards Test Bench for Aspiration Catheters in Realistic Evaluation Scenarios". Current Directions in Biomedical Engineering 8, nr 2 (1.08.2022): 185–88. http://dx.doi.org/10.1515/cdbme-2022-1048.

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Abstract Aspiration catheters play an important role in mechanical thrombectomy in interventional neuroradiology as they provide support for stent retrievers or are increasingly used separately for contact aspiration. To evaluate the performance of different aspiration catheters in terms of suction force, most current studies rely on manual measurement methods or the suction force is not measured close to the aspiration catheter tip. Moreover, there is currently no standardized method that records measurements digitally and with high temporal resolution. To overcome these challenges, we propose a new test bench that simulates a dedicated aspiration scenario and takes measurements close to the aspiration catheter tip. To meet the requirements, a simplified vascular phantom, a pressure sensor and a simplified clot model were implemented in the prototype. To demonstrate the applicability of the prototype, two commonly used aspiration catheters were evaluated. The obtained measurements show that it is possible to perform standardized comparisons between aspiration catheters from different manufacturers as well as different aspiration pumps and aspiration tubings and their combinations. The developed prototype overcomes the still widely used manual and semimanual and thus error prone measurement methods for the evaluation of vacuum based thrombectomy systems.

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Bunch, T. Jared. "Excessive contact force can overcome irrigated tip catheter benefits during atrial fibrillation ablation". Journal of Cardiovascular Electrophysiology 29, nr 2 (14.12.2017): 236–38. http://dx.doi.org/10.1111/jce.13391.

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Perna, Francesco, E. Kevin Heist, Stephan B. Danik, Conor D. Barrett, Jeremy N. Ruskin i Moussa Mansour. "Assessment of Catheter Tip Contact Force Resulting in Cardiac Perforation in Swine Atria Using Force Sensing Technology". Circulation: Arrhythmia and Electrophysiology 4, nr 2 (kwiecień 2011): 218–24. http://dx.doi.org/10.1161/circep.110.959429.

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Kluzik, Anna, Hanna Tomczak, Marek Nowicki, Tomasz Koszel, Alicja Bartkowska-Śniatkowska, Krzysztof Kusza i Małgorzata Grześkowiak. "Atomic force microscopy and scanning electron microscopy as alternative methods of early identification of pathogens causing catheter-related bloodstream infections of patients in ICU". Postępy Higieny i Medycyny Doświadczalnej 76, nr 1 (1.01.2022): 157–64. http://dx.doi.org/10.2478/ahem-2022-0010.

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Abstract Introduction Vascular catheters are an indispensable element of the therapy of patients in intensive care. Their use is associated with the possibility of complications, including infectious. According to various sources, the incidence of catheter-related bloodstream infections (CRBSIs) ranges from 0.1 to 22.7 per 1,000 catheter days. Materials and Methods The central venous catheter tip culture samples were collected from 24 patients with suspected catheter-related bloodstream infection, from three intensive care units (ICUs). The results of microscopic examinations: atomic force microscope (AFM) and scanning electron microscope (SEM) were compared with the results of microbiological analysis of the central venous catheter tip and blood collected from the catheter. Results The microscopic examination and microbiological analysis of both the blood and central venous catheter samples confirmed the presence of microorganisms in 16 cases (double positive result). Our study was conducted in a short period of time (up to 6 hours) and it gave an initial answer to the question about the type of microorganisms colonising the central venous catheter. In one patient the infection was not caused by removal of the central venous catheter. However, not all results were fully consistent within the two diagnostic methods. The colonisation of the central venous catheter with Pseudomonas aeruginosa and Staphylococcus epidermidis was microbiologically confirmed, but it was not confirmed by the microscopic examination of the sample collected from patient No. 20. However, the examination enabled preliminary assessment of the microorganism colonising the catheter, which may have caused the blood infection. It cannot be ruled out that Pseudomonas aeruginosa bacilli were grown on the catheter that came into contact with blood from another source of infection, e.g. the respiratory, nervous or urinary systems. Information on the presence of cocci-shaped bacteria forming characteristic clusters or rods may enable initial diagnosis of catheter-related bloodstream infection if it is accompanied by typical clinical symptoms. Alternative diagnostics also provides valuable information on the presence of biofilm, which is a factor hindering the body’s response to infection and penetration of antibiotics. Conclusions Our pilot study presents new diagnostic possibilities of microscopic imaging with the atomic force microscope (AFM) and scanning electron microscope (SEM) to identify pathogens on routinely used disposable medical devices, such as the central venous catheter. On the other hand, this range of diagnostics reveals the potential to constantly improve medical materials which come into direct contact with patients’ tissues. It is important to create a database of microscopic images, which would be a repeatable diagnostic pattern and fully correlated with the results of microbiological analysis, because it would facilitate initial quick diagnosis of a potential CRBSI.

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Rozprawy doktorskie na temat "Catheter tip contact force"

Lübbe, Jannis Ralph Ulrich. "Cantilever properties and noise figures in high-resolution non-contact atomic force microscopy". Doctoral thesis, 2013. https://repositorium.ub.uni-osnabrueck.de/handle/urn:nbn:de:gbv:700-2013040310741.

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Different methods for the determination of cantilever properties in non-contact atomic force microscopy (NC-AFM) are under investigation. A key aspect is the determination of the cantilever stiffness being essential for a quantitative NC-AFM data analysis including the extraction of the tip-surface interaction force and potential. Furthermore, a systematic analysis of the displacement noise in the cantilever oscillation detection is performed with a special focus on the thermally excited cantilever oscillation. The propagation from displacement noise to frequency shift noise is studied under consideration of the frequency response of the PLL demodulator. The effective Q-factor of cantilevers depends on the internal damping of the cantilever as well as external influences like the ambient pressure and the quality of the cantilever fixation. While the Q-factor has a strong dependence on the ambient pressure between vacuum and ambient pressure yielding a decrease by several orders of magnitude, the pressure dependence of the resonance frequency is smaller than 1% for the same pressure range. On the other hand, the resonance frequency highly depends on the mass of the tip at the end of the cantilever making its reliable prediction from known cantilever dimensions difficult. The cantilever stiffness is determined with a high-precision static measurement method and compared to dimensional and dynamic methods. Dimensional methods suffer from the uncertainty of the measured cantilever dimensions and require a precise knowledge its material properties. A dynamic method utilising the measurement of the thermally excited cantilever displacement noise to obtain cantilever properties allows to characterise unknown cantilevers but requires an elaborative measurement equipment for spectral displacement noise analysis. Having the noise propagation in the NC-AFM system fully characterised, a proposed method allows for spring constant determination from the frequency shift noise at the output of the PLL demodulator with equipment already being available in most NC-AFM setups.

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Yapici, Murat K. "Development of Micromachined Probes for Bio-Nano Applications". 2009. http://hdl.handle.net/1969.1/ETD-TAMU-2009-08-6966.

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The most commonly known macro scale probing devices are simply comprised of metallic leads used for measuring electrical signals. On the other hand, micromachined probing devices are realized using microfabrication techniques and are capable of providing very fine, micro/nano scale interaction with matter; along with a broad range of applications made possible by incorporating MEMS sensing and actuation techniques. Micromachined probes consist of a well-defined tip structure that determines the interaction space, and a transduction mechanism that could be used for sensing a change, imparting external stimuli or manipulating matter. Several micromachined probes intended for biological and nanotechnology applications were fabricated, characterized and tested. Probes were developed under two major categories. The first category consists of Micro Electromagnetic Probes for biological applications such as single cell, particle, droplet manipulation and neuron stimulation applications; whereas the second category targets novel Scanning Probe topologies suitable for direct nanopatterning, variable resolution scanning probe/dip-pen nanolithography, and biomechanics applications. The functionality and versatility of micromachined probes for a broad range of micro and nanotechnology applications is successfully demonstrated throughout the five different probes/applications that were studied. It is believed that, the unique advantages of precise positioning capability, confinement of interaction as determined by the probe tip geometry, and special sensor/actuator mechanisms incorporated through MEMS technologies will render micromachined probes as indispensable tools for microsystems and nanotechnology studies.

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Książki na temat "Catheter tip contact force"

Heithaus, Evans, Almas Syed i Chet R. Rees. Advancing the Difficult Drainage Catheter. Redaktorzy S. Lowell Kahn, Bulent Arslan i Abdulrahman Masrani. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199986071.003.0097.

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Advancing a drainage catheter can be difficult in certain situations, particularly when the catheter “accordions” upon itself. Most tubes are built with a small shelf in the tip of the catheter, and metal and plastic stiffeners are provided. Applying the majority of the advancing force at the hub of the metal stiffener rather than along the midportion of the catheter exerts force at the tip of the catheter via the internal metal stiffener, which is lodged against the small shelf inside the catheter. Using this method, the operator is able to translate a majority of the forward force to the catheter tip, thereby “pulling” the rest of the catheter through tissues and thus reducing the accordion effect.

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Części książek na temat "Catheter tip contact force"

Salvatori, Carlotta, Diego Trucco, Ignazio Niosi, Leonardo Ricotti i Lorenzo Vannozzi. "A Novel Steerable Catheter Controlled with a Biohybrid Actuator: A Feasibility Study". W Biomimetic and Biohybrid Systems, 378–93. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-39504-8_26.

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AbstractTargeted therapies allow increasing the efficacy of treatments for several diseases, including cancer. The release of drugs or chemicals directly in the site of interest will be beneficial for maximizing the therapy and minimize side effects.Here, we report the concept and a preliminary analysis of an innovative intravascular steerable catheter guided by an on-board biohybrid actuator, aiming to release drugs into deep and tortuous regions within the cardiovascular systems. The catheter performance has been estimated through analytical and numerical analyses, varying catheter diameter, wall thickness, and actuator force. Results show how larger catheter deflections can be obtained with a smaller outer diameter and decreasing wall thickness. Besides, improved outcomes can be achieved by applying the biohybrid actuator distant from the catheter tip extremity and maximizing the magnitude of the applied forces. Despite the need to further improve the performance of this concept (e.g., by decreasing material stiffness), these preliminary results show great promise in view of future experimentation of such kind of actuation to drive microcatheters through the cardiovascular network.

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Karim, Rashed, Gang Gao, James Harrison, Aruna Arujuna, Hendrik Lambert, Giovanni Leo, Jaswinder Gill i in. "Mapping Contact Force during Catheter Ablation for the Treatment of Atrial Fibrillation: New Insights into Ablation Therapy". W Functional Imaging and Modeling of the Heart, 302–3. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-21028-0_37.

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"When the Tip Contacts the Substrate: Contact Mechanics". W Fundamentals of Atomic Force Microscopy, 131–62. WORLD SCIENTIFIC, 2015. http://dx.doi.org/10.1142/9789814630368_0005.

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Krishnan, Kannan M. "Scanning Probe Microscopy". W Principles of Materials Characterization and Metrology, 745–802. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198830252.003.0011.

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Scanning probe microscopy (SPM) scans a fine tip close to a surface and measures the tunneling current (STM) or force (SFM), based on many possible tip-surface interactions. STM provides atomic resolution imaging, or the local electronic structure (spectroscopy) as a function of bias voltage, and is also used to manipulate adsorbed atoms on a clean surface. STM operates in two modes— constant current or height—and requires a conducting specimen. SFM uses a cantilever (force sensor) to measure short range (< 1 nm) chemical, and a variety of long-range (< 100 nm) forces, depending on the tip and the specimen; a conducting specimen is not required. In static mode, the tip height is controlled to maintain a constant force, and measure surface topography. In dynamic mode, changes in the vibrational properties of the cantilever are measured using frequency, amplitude, or phase modulation as feedback to control the tip-surface distance and form the image. Dynamic imaging includes contact and non-contact modes, but intermittent contact or tapping mode is common. SPMs measure properties (optical, acoustic, conductance, electrochemical, capacitance, thermal, magnetic, etc.) using appropriate tips, and find applications in the physical and life sciences. They are also used for nanoscale lithography.

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Chen, C. Julian. "Nanomechanical Effects". W Introduction to Scanning Tunneling Microscopy, 253–72. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198856559.003.0009.

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This chapter discusses the effect of force and deformation of the tip apex and the sample surface in the operation and imaging mechanism of STM and AFM. Because the contact area is of atomic dimension, a very small force and deformation would generate a large measurable effect. Three effects are discussed. First is the stability of the STM junction, which depends on the rigidity of the material. For soft materials, hysterisis is more likely. For rigid materials, the approaching and retraction cycles are continuous and reproducible. Second is the effect of force and deformation to the STM imaging mechanism. For soft material such as graphite, force and deformation can amplify the observed corrugation. For hard materials as most metals, force and deformation can decrease the observed corrugation. Finally, the effect of force and deformation on tunneling barrier height measurements is discussed.

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Desai, Manishi. "Intraocular Pressure Measurement". W Glaucoma. Oxford University Press, 2012. http://dx.doi.org/10.1093/oso/9780199757084.003.0006.

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Intraocular pressure (IOP) measurement is a key test by which patients with glaucoma are clinically monitored. Clinical trials have demonstrated that a reduction in IOP results in a reduction in the risk of progression of glaucoma. Accordingly, measuring IOP with relative accuracy is very important in managing patients. There are multiple methods to measure IOP. The method used may depend on the particular clinical setting. All are surrogate measures in comparison to manometry (i.e., IOP measurement using an intracameral cannula), which is the most direct means to measure IOP. However, manometry is not practical for everyday clinical practice since it is invasive. This overview provides information about currently available methods to measure IOP and how they may be best applied. This section also outlines the advantages and disadvantages involved with these methods. Not all techniques are available to every practitioner, but knowing the principles behind these methods and the limitations should allow clinicians to more carefully interpret and reliably obtain IOP measurements using the techniques at their disposal. Goldmann applanation tonometry (GAT) is considered to be the standard by which IOP is measured for the average patient (i.e., average corneal thickness without apparent corneal abnormalities). GAT is also likely the measurement modality most readily available to practitioners. The Perkins tonometer is a handheld Goldmann applanation device (Fig. 1.1B). This is helpful when measuring IOP in children as it can be used in the upright or supine position and for patients unable to come to the slit lamp. Based on the Imbert-Fick principle Applanation diameter is 3.06 mm (not the size of the applanation tip, which is larger), so that 1 g of force represents 10 mmHg. Assumes the eye is a sphere, corneal thickness is estimated to be 0.52 mm, and volume displaced by contact is negligible Instill topical anesthetic and fluorescein dye. Clean tip (see recommended cleaning technique at end of this section). Position patient at slit lamp (for GAT). Set illumination to cobalt blue filter and set force knob/drum to 1 (which corresponds to 10 mmHg).

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"Figure 9.4 The effect of tendon tension on carpal tunnel pressure and median nerve contact stress. Flexor tendons loaded with 10N force. Hydrostatic pressure was measured by catheter and contact stress by a tubular rubber transducer replacing the excised median nerve (Keir et al., 1997)". W Biomechanics in Ergonomics, 200–201. CRC Press, 1999. http://dx.doi.org/10.4324/9780203016268-39.

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Mattei, Eugenio, Giovanni Calcagnini, Michele Triventi, Federica Censi, Pietro Bartolini, Wolfgang Kainz i Howard Bassen. "MRI Induced Heating on Pacemaker Leads". W Encyclopedia of Healthcare Information Systems, 950–57. IGI Global, 2008. http://dx.doi.org/10.4018/978-1-59904-889-5.ch117.

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Magnetic resonance imaging (MRI) is a widely accepted tool for the diagnosis of a variety of disease states. The presence of a metallic implant, such as a cardiac pacemaker (PM), or the use of conductive structures in interventional therapy, such as guide wires or catheters, are currently considered a strong contraindication to MRI (Kanal, Borgstede, Barkovich, Bell, Bradley, Etheridge, Felmlee, Froelich, Hayden, Kaminski, Lester, Scoumis, Zaremba, & Zinninger, 2002; Niehaus & Tebbenjohanns, 2001; Shellock & Crues, 2002). Potential effects of MRI on PMs’ implantable cardioverter defibrillator (ICDs) include: force and torque effects on the PM (Luechinger, Duru, Scheidegger, Boesiger, & Candinas, 2001; Shellock, Tkach, Ruggieri, & Masaryk, 2003); undefined reed-switch state within the static magnetic field (Luechinger, Duru, Zeijlemaker, Scheidegger, Boesiger, & Candinas, 2002); potential risk of heart stimulation and inappropriate pacing (Erlebacher, Cahill, Pannizzo, & Knowles, 1986; Hayes, Holmes, & Gray, 1987); and heating effects at the lead tip (Achenbach, Moshage, Diem, Bieberle, Schibgilla, & Bachmann, 1997; Luechinger, Zeijlemaker, Pedersen, Mortensen, Falk, Duru, Candinas, & Boesiger, 2005; Sommer, Vahlhaus, Lauck, von Smekal, Reinke, Hofer, Block, Traber, Schneider, Gieseke, Jung, & Schild, 2000). In particular, most of the publications dealing with novel MRI techniques on patients with implanted linear conductive structures (Atalar, Kraitchman, Carkhuff, Lesho, Ocali, Solaiyappan, Guttman, & Charles, 1998; Baker, Tkach, Nyenhuis, Phillips, Shellock, Gonzalez-Martinez, & Rezai, 2004; Nitz, Oppelt, Renz, Manke, Lenhart, & Link, 2001) point out that the presence of these structures may produce an increase in power deposition around the wire or the catheter. Unfortunately, this increased local specific absorption rate (SAR) is potentially harmful to the patient, due to an excessive temperature increase which can bring living tissues to necrosis. The most direct way to get a measure of the SAR deposition along the wire is by using a temperature probe: the use of fluoroptic® thermometry to measure temperature has become “state-of-the-art,” and is the industry standard in this field (Shellock, 1992; Wickersheim et al., 1987). When the investigation involves small objects and large spatial temperature gradients, the measurement of the temperature increase and of the local SAR may become inaccurate, unless several precautions are taken. It seems obvious to: (1) evaluate the error associated with temperature increase and SAR measurements; (2) define a standard protocol for probe positioning, which minimizes the error associated with temperature measurement.

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Streszczenia konferencji na temat "Catheter tip contact force"

Roshanfar, Majid, Pedram Fekri i Javad Dargahi. "A Deep Learning Model for Tip Force Estimation on Steerable Catheters Via Learning-From-Simulation". W THE HAMLYN SYMPOSIUM ON MEDICAL ROBOTICS. The Hamlyn Centre, Imperial College London London, UK, 2023. http://dx.doi.org/10.31256/hsmr2023.17.

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Atrial Fibrillation (AFib) is the most common arrhyth- mia among the elderly population, where electrical activity becomes chaotic, leading to blood clots and strokes. During Radio Frequency Ablation (RFA), the arrhythmogenic sites within the cardiac tissue are burned off to reduce the undesired pulsation. Manual catheters are used for most atrial ablations, however, robotic catheter intervention systems provide more precise map- ping. Several studies showed excessive contact forces (> 0.45 N) increase the incidence of tissue perforation, while inadequate force (< 0.1 N) results in ineffective ablation. Fig.1 shows a schematic of a cardiac RFA catheter used for AFib treatment. For robot-assisted RFA to be safe and effective, real-time force estimation of catheter’s tip is required. As a solution, finite element (FE) analysis can provide a useful tool to estimate the real-time tip contact force. In this work, a nonlinear planar FE model of a steerable catheter was first developed with parametric material properties in ANSYS software. After that, a series of simulations based on each mechanical property was performed, and the deformed shape of the catheter was recorded. Next, validation was conducted by comparing the results of the simulation with experimental results between the range of 0-0.45 N to determine the material properties. Despite the previous work, which was a study to estimate the tip contact force of a catheter using a deep convolutional neural network [1], [2], the main contribution of this study was proposing a synthetic data generation, so as to train a light deep learning (DL) architecture for tip force estimation according to the FE simulations. Due to the availability of real-time X-ray images during RFA procedures (fluoroscopy), the shape of the catheter is available intraoperatively. The proposed solution not only feeds the data-hungry methods based on DL with a sufficient amount of data, but also shows the feasibility of replacing the fast, accurate, and light-weight learning-based methods with slow simulations.

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Shi, Xiaochan, Xuelian Gu, Jiahong Tan i Bo Liang. "A New Design of the Miniature Force Sensor Based on Strain Gages for Ablation Catheter". W 2017 Design of Medical Devices Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/dmd2017-3413.

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Recently, the radiofrequency ablation catheter is widely used in the treatment of atrial fibrillation. Radiofrequency catheter tip is inserted through femoral vein puncture and pushed to the heart cavity. The radio frequency energy is applied to the ablation lesion on the inner wall of the heart, and then the heart cells die to achieve the aim of treatment[1]. During the treatment, however, the patients need repeated ablation because of the ineffective ablation, and the complications may occur. Continuous pulmonary vein lesion and isolation of wall is very important to increase the success of surgery [2]. Research [3] shows that the contact force between catheter tip and the tissue of inner heart is a key factor influencing the lesion size. In order to monitor the contact force, many force sensors have been studied. Fukuda [4] used semiconductor strain gage outside of the catheter to monitor the contact force. Peirs [5] monitored the contact force by optical technology. The disadvantages of the current sensors are using special expensive signal detecting and analyzing instrument, such as Endosense (SMART touch), which will increase the cost tremendously. For clinical application, it is necessary to develop a low cost sensor with enough accuracy which can also be used in the catheter for contact force measurement. This paper focuses on designing a novel force-voltage transferring sensor. The sensor consists of a Ni-Ti alloy tube and several strain gages. With the compact design of a spiral structure, it can reduce the overall cost while keeping a good performance at the same time. The price of SMART touch catheter is 4, 348 dollars. The proposed design will be as much as 20–30 percent below SMART’s price.

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Jin, Xiaoliang, Shuxiang Guo, Jian Guo, Peng Shi i Xinming Li. "Preliminary Method for Reducing Contact Force between Catheter Tip and Vessel Wall in Endovascular Surgery". W 2021 IEEE International Conference on Mechatronics and Automation (ICMA). IEEE, 2021. http://dx.doi.org/10.1109/icma52036.2021.9512638.

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Jin, Xiaoliang, Shuxiang Guo, Jian Guo, Peng Shi i Dapeng Song. "A Method for Obtaining Contact Force between Catheter Tip and Vascular Wall in Master-slave Robotic System". W 2020 IEEE International Conference on Mechatronics and Automation (ICMA). IEEE, 2020. http://dx.doi.org/10.1109/icma49215.2020.9233611.

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Ijima, Yukako, Kriengsak Masnok, Juan J. Perez, Ana González-Suárez, Enrique Berjano i Nobuo Watanabe. "Relationship Between Mechanical Deformation and Contact Force Applied by Catheter Tip on Cardiac Muscle: Experimentation and Computer Modeling". W 2023 IEEE 5th Eurasia Conference on Biomedical Engineering, Healthcare and Sustainability (ECBIOS). IEEE, 2023. http://dx.doi.org/10.1109/ecbios57802.2023.10218520.

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Khoshbakht, Reza, Mojtaba Kheiri, Javad Dargahi i Amir Hooshiar. "Effects of Blood Flow on the Tip Contact Force of Cardiac Ablation Catheters". W 2022 IEEE International Symposium on Robotic and Sensors Environments (ROSE). IEEE, 2022. http://dx.doi.org/10.1109/rose56499.2022.9977429.

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Chatzipirpiridis, G., S. Gervasoni, F. Berlinger, S. Blaz, O. Ergeneman, S. Pane i B. J. Nelson. "Miniaturized magnetic force sensor on a catheter tip". W TRANSDUCERS 2015 - 2015 18th International Solid-State Sensors, Actuators and Microsystems Conference. IEEE, 2015. http://dx.doi.org/10.1109/transducers.2015.7181278.

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Koch, Martin, Alexander Brost, Atilla Kiraly, Norbert Strobel i Joachim Hornegger. "Post-procedural evaluation of catheter contact force characteristics". W SPIE Medical Imaging, redaktorzy Bram van Ginneken i Carol L. Novak. SPIE, 2012. http://dx.doi.org/10.1117/12.912315.

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Obata, K. J., S. Saito i K. Takahashi. "Expansion of capillary force range by probe-tip curvature". W CONTACT/SURFACE 2007. Southampton, UK: WIT Press, 2007. http://dx.doi.org/10.2495/secm070311.

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Pandya, Hardik J., Jun Sheng i Jaydev P. Desai. "Towards a tri-axial flexible force sensor for catheter contact force measurement". W 2016 IEEE SENSORS. IEEE, 2016. http://dx.doi.org/10.1109/icsens.2016.7808954.

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Raporty organizacyjne na temat "Catheter tip contact force"

Law, Edward, Samuel Gan-Mor, Hazel Wetzstein i Dan Eisikowitch. Electrostatic Processes Underlying Natural and Mechanized Transfer of Pollen. United States Department of Agriculture, maj 1998. http://dx.doi.org/10.32747/1998.7613035.bard.

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The project objective was to more fully understand how the motion of pollen grains may be controlled by electrostatic forces, and to develop a reliable mechanized pollination system based upon sound electrostatic and aerodynamic principles. Theoretical and experimental analyses and computer simulation methods which investigated electrostatic aspects of natural pollen transfer by insects found that: a) actively flying honeybees accumulate ~ 23 pC average charge (93 pC max.) which elevates their bodies to ~ 47 V likely by triboelectrification, inducing ~ 10 fC of opposite charge onto nearby pollen grains, and overcoming their typically 0.3-3.9 nN detachment force resulting in non-contact electrostatic pollen transfer across a 5 mm or greater air gap from anther-to-bee, thus providing a theoretical basis for earlier experimental observations and "buzz pollination" events; b) charge-relaxation characteristics measured for flower structural components (viz., 3 ns and 25 ns time constants, respectively, for the stigma-style vs. waxy petal surfaces) ensure them to be electrically appropriate targets for electrodeposition of charged pollen grains but not differing sufficiently to facilitate electrodynamic focusing onto the stigma; c) conventional electrostatic focusing beneficially concentrates pollen-deposition electric fields onto the pistill tip by 3-fold as compared to that onto underlying flower structures; and d) pollen viability is adequately maintained following exposure to particulate charging/management fields exceeding 2 MV/m. Laboratory- and field-scale processes/prototype machines for electrostatic application of pollen were successfully developed to dispense pollen in both a dry-powder phase and in a liquid-carried phase utilizing corona, triboelectric, and induction particulate-charging methods; pollen-charge levels attained (~ 1-10 mC/kg) provide pollen-deposition forces 10-, 77-, and 100-fold greater than gravity, respectively, for such charged pollen grains subjected to a 1 kV/cm electric field. Lab and field evaluations have documented charged vs. ukncharged pollen deposition to be significantly (a = 0.01-0.05) increased by 3.9-5.6 times. Orchard trials showed initial fruit set on branches individually treated with electrostatically applied pollen to typically increase up to ~ 2-fold vs. uncharged pollen applications; however, whole-tree applications have not significantly shown similar levels of benefit and corrective measures continue. Project results thus contribute important basic knowledge and applied electrostatics technology which will provide agriculture with alternative/supplemental mechanized pollination systems as tranditional pollen-transfer vectors are further endangered by natural and man-fade factors.

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