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Laser coagulation and hemostasis of large diameter blood vessels: effect of shear stress and flow velocity. Sci Rep 2022; 12:8375. [PMID: 35589781 PMCID: PMC9120470 DOI: 10.1038/s41598-022-12128-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 04/29/2022] [Indexed: 11/08/2022] Open
Abstract
Photocoagulation of blood vessels offers unambiguous advantages to current radiofrequency approaches considering the high specificity of blood absorption at available laser wavelengths (e.g., 532 nm and 1.064 µm). Successful treatment of pediatric vascular lesions, such as port-wine stains requiring microvascular hemostasis, has been documented. Although laser treatments have been successful in smaller diameter blood vessels, photocoagulation of larger sized vessels is less effective. The hypothesis for this study is that a primary limitation in laser coagulation of large diameter blood vessels (500-1000 µm) originates from shear stress gradients associated with higher flow velocities along with temperature-dependent viscosity changes. Laser (1.07 µm) coagulation of blood vessels was tested in the chicken chorio-allantoic membrane (CAM). A finite element model is developed that includes hypothetical limitations in laser coagulation during irradiation. A protocol to specify laser dosimetry is derived from OCT imaging and angiography observations as well as finite element model results. Laser dosimetry is applied in the CAM model to test the experimental hypothesis that blood shear stress and flow velocity are important parameters for laser coagulation and hemostasis of large diameter blood vessels (500-1000 µm). Our experimental results suggest that shear stress and flow velocity are fundamental in the coagulation of large diameter blood vessels (500-1000 µm). Laser dosimetry is proposed and demonstrated for successful coagulation and hemostasis of large diameter CAM blood vessels.
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Bianchi L, Cavarzan F, Ciampitti L, Cremonesi M, Grilli F, Saccomandi P. Thermophysical and mechanical properties of biological tissues as a function of temperature: a systematic literature review. Int J Hyperthermia 2022; 39:297-340. [DOI: 10.1080/02656736.2022.2028908] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Leonardo Bianchi
- Department of Mechanical Engineering, Politecnico di Milano, Milan, Italy
| | - Fabiana Cavarzan
- Department of Mechanical Engineering, Politecnico di Milano, Milan, Italy
| | - Lucia Ciampitti
- Department of Mechanical Engineering, Politecnico di Milano, Milan, Italy
| | - Matteo Cremonesi
- Department of Mechanical Engineering, Politecnico di Milano, Milan, Italy
| | - Francesca Grilli
- Department of Mechanical Engineering, Politecnico di Milano, Milan, Italy
| | - Paola Saccomandi
- Department of Mechanical Engineering, Politecnico di Milano, Milan, Italy
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De Vita E, De Landro M, Massaroni C, Iadicicco A, Saccomandi P, Schena E, Campopiano S. Fiber Optic Sensors-Based Thermal Analysis of Perfusion-Mediated Tissue Cooling in Liver Undergoing Laser Ablation. IEEE Trans Biomed Eng 2021; 68:1066-1073. [PMID: 32746040 DOI: 10.1109/tbme.2020.3004983] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The current challenge in the field of thermo-ablative treatments of tumors is to achieve a balance between complete destruction of malignant cells and safeguarding of the surrounding healthy tissue. Blood perfusion plays a key role for thermal ablation success, especially in the case of highly vascularized organs like liver. This work aims at monitoring the temperature within perfused swine liver undergoing laser ablation (LA). Temperature was measured through seven arrays of Fiber Bragg Grating sensors (FBGs) around the laser applicator. To mimic reality, blood perfusion within the ex-vivo liver was simulated using artificial vessels. The influence of blood perfusion on LA was carried out by comparing the temperature profiles in two different spatial configurations of vessels and fibers. The proposed setup permitted to accurately measure the heat propagation in real-time with a temperature resolution of 0.1 °C and to observe a relevant tissue cooling near to the vessel up to 65%.
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Van De Steeg MGM, Van De Vosse FN, Pijls NHJ, Van 't Veer M. Quantification of the temperature gradient through a catheter in continuous infusion thermodilution for coronary flow measurements. Physiol Meas 2020; 41:075006. [PMID: 32464612 DOI: 10.1088/1361-6579/ab979d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Quantifying the absolute coronary blood flow can be done using continuous infusion thermodilution requiring a dedicated infusion catheter. Up to now, there has been little insight into the effect of small variabilities in the physical parameters on the temperature gradient along this catheter. The key goal of this study is to develop and validate a computer model that predicts the temperature of the infusion fluid at the infusion site of the infusion catheter. A secondary goal is to gain insight into the influence of physical variations for the individual patient on the calculated blood flow rate. APPROACH A numerical model of the temperature in the catheter was built using the convection-diffusion equation and validated using an in vitro setup. A sensitivity analysis was performed to investigate the influence of the catheter path inside the body and the temperature of the infusion fluid at different infusion rates. These results were compared to in vivo measurements of 94 patients. Finally, the variation in the computed blood flow rate is estimated considering an average patient, using small variations in the physical parameters. MAIN RESULTS The computed temperature corresponded well with the in vitro measurements, since a maximal difference of 1.5% was observed. The length of the catheter path inside the body had the most influence on the temperature of the infusion fluid at the infusion site. Moreover, temperatures from the numerical model were similar to the results from in vivo measurements. By varying the length of the catheters with 0.04 m, the largest deviation in the calculated blood flow was 33.3 ml/min. SIGNIFICANCE Insight is gained into the influence of physical variations on the temperature of the infusion fluid at the infusion site of the catheter using thermodilution. The developed numerical model can possibly be used to reduce time in estimating the blood flow rate.
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Current Solutions for the Heat-Sink Effect of Blood Vessels with Radiofrequency Ablation: A Review and Future Work. COMMUNICATIONS IN COMPUTER AND INFORMATION SCIENCE 2017. [DOI: 10.1007/978-981-10-6370-1_12] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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CONSIGLIERI LUISA. ANALYTICAL SOLUTIONS IN THE MODELING OF THE LOCAL RF ABLATION. J MECH MED BIOL 2016. [DOI: 10.1142/s0219519416500718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Coupled mathematical models for the radiofrequency (RF) ablation performed in biomedical sciences have been developed based on the bioheat transfer theory. The heat exchange problem is important to be analytically studied in order to control the size of the necrosis zone caused by RF ablation. This lesion size in the tissue may be predicted by the knowledge of the internal tissue temperature. We propose an analytical solution for the Pennes heat transfer equation in bi- and tri-region domains, applicable to the RF ablation of cancerigeneous tissue — a clinical relevant problem. The model consists of two partial differential equations describing the spatio-temporal interactions between the electric and thermic effects. The aim is to find simple algebraic expressions of analytical solutions that may allow to generate quantitative results which in turn may be interpreted (including uncertainties). The dependence of the temperature as function of the electrothermal parameters in both diseased and surrounding healthy tissues is pointed out. Two cases, namely the tumor–tissue and tumor–tissue–skin systems, are graphically computed, and important findings include the fact that the presence of tissue with smaller value parameters protects somehow healthy cells. Moreover, the graphical representations are conducted to highlight the link of the profile of current density distribution in the physiological problem with the (neither oval nor circular) shape of the temperature isoclinic lines.
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Chiang J, Birla S, Bedoya M, Jones D, Subbiah J, Brace CL. Modeling and validation of microwave ablations with internal vaporization. IEEE Trans Biomed Eng 2014; 62:657-63. [PMID: 25330481 DOI: 10.1109/tbme.2014.2363173] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Numerical simulation is increasingly being utilized for computer-aided design of treatment devices, analysis of ablation growth, and clinical treatment planning. Simulation models to date have incorporated electromagnetic wave propagation and heat conduction, but not other relevant physics such as water vaporization and mass transfer. Such physical changes are particularly noteworthy during the intense heat generation associated with microwave heating. In this paper, a numerical model was created that integrates microwave heating with water vapor generation and transport by using porous media assumptions in the tissue domain. The heating physics of the water vapor model was validated through temperature measurements taken at locations 5, 10, and 20 mm away from the heating zone of the microwave antenna in homogenized ex vivo bovine liver setup. Cross-sectional area of water vapor transport was validated through intraprocedural computed tomography (CT) during microwave ablations in homogenized ex vivo bovine liver. Iso-density contours from CT images were compared to vapor concentration contours from the numerical model at intermittent time points using the Jaccard index. In general, there was an improving correlation in ablation size dimensions as the ablation procedure proceeded, with a Jaccard index of 0.27, 0.49, 0.61, 0.67, and 0.69 at 1, 2, 3, 4, and 5 min, respectively. This study demonstrates the feasibility and validity of incorporating water vapor concentration into thermal ablation simulations and validating such models experimentally.
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González-Suárez A, Trujillo M, Burdío F, Andaluz A, Berjano E. Could the heat sink effect of blood flow inside large vessels protect the vessel wall from thermal damage during RF-assisted surgical resection? Med Phys 2014; 41:083301. [DOI: 10.1118/1.4890103] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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Paul A, Narasimhan A, Kahlen FJ, Das SK. Temperature evolution in tissues embedded with large blood vessels during photo-thermal heating. J Therm Biol 2014; 41:77-87. [PMID: 24679976 DOI: 10.1016/j.jtherbio.2014.02.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 12/24/2013] [Accepted: 02/05/2014] [Indexed: 11/25/2022]
Abstract
During laser-assisted photo-thermal therapy, the temperature of the heated tissue region must rise to the therapeutic value (e.g., 43°C) for complete ablation of the target cells. Large blood vessels (larger than 500 micron in diameter) at or near the irradiated tissues have a considerable impact on the transient temperature distribution in the tissue. In this study, the cooling effects of large blood vessels on temperature distribution in tissues during laser irradiation are predicted using finite element based simulation. A uniform flow is assumed at the entrance and three-dimensional conjugate heat transfer equations in the tissue region and the blood region are simultaneously solved for different vascular models. A volumetric heat source term based on Beer-Lambert law is introduced into the energy equation to account for laser heating. The heating pattern is taken to depend on the absorption and scattering coefficients of the tissue medium. Experiments are also conducted on tissue mimics in the presence and absence of simulated blood vessels to validate the numerical model. The coupled heat transfer between thermally significant blood vessels and their surrounding tissue for three different tissue-vascular networks are analyzed keeping the laser irradiation constant. A surface temperature map is obtained for different vascular models and for the bare tissue (without blood vessels). The transient temperature distribution is seen to differ according to the nature of the vascular network, blood vessel size, flow rate, laser spot size, laser power and tissue blood perfusion rate. The simulations suggest that the blood flow through large blood vessels in the vicinity of the photothermally heated tissue can lead to inefficient heating of the target.
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Affiliation(s)
- Anup Paul
- Heat Transfer and Thermal Power Laboratory, Department of Mechanical Engineering, IIT Madras, Chennai, Tamilnadu 600036, India
| | - Arunn Narasimhan
- Heat Transfer and Thermal Power Laboratory, Department of Mechanical Engineering, IIT Madras, Chennai, Tamilnadu 600036, India
| | - Franz J Kahlen
- Department of Mechanical Engineering, University of Cape Town, Rondebosch 7701, Republic of South Africa
| | - Sarit K Das
- Heat Transfer and Thermal Power Laboratory, Department of Mechanical Engineering, IIT Madras, Chennai, Tamilnadu 600036, India.
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Abstract
Microwave tissue heating is being increasingly utilised in several medical applications, including focal tumour ablation, cardiac ablation, haemostasis and resection assistance. Computational modelling of microwave ablations is a precise and repeatable technique that can assist with microwave system design, treatment planning and procedural analysis. Advances in coupling temperature and water content to electrical and thermal properties, along with tissue contraction, have led to increasingly accurate computational models. Developments in experimental validation have led to broader acceptability and applicability of these newer models. This review will discuss the basic theory, current trends and future direction of computational modelling of microwave ablations.
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Affiliation(s)
- Jason Chiang
- Department of Radiology, University of Wisconsin – Madison, Madison WI
- Department of Biomedical Engineering, University of Wisconsin – Madison, Madison WI
| | - Peng Wang
- Department of Radiology, University of Wisconsin – Madison, Madison WI
| | - Christopher L. Brace
- Department of Radiology, University of Wisconsin – Madison, Madison WI
- Department of Biomedical Engineering, University of Wisconsin – Madison, Madison WI
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Nan Q, Zheng W, Fan Z, Liu Y, Zeng Y. Analysis to a critical state of thermal field in microwave ablation of liver cancer influenced by large vessels. Int J Hyperthermia 2010; 26:34-8. [DOI: 10.3109/02656730903419257] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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12
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dos Santos I, Haemmerich D, Pinheiro CDS, da Rocha AF. Effect of variable heat transfer coefficient on tissue temperature next to a large vessel during radiofrequency tumor ablation. Biomed Eng Online 2008; 7:21. [PMID: 18620566 PMCID: PMC2500024 DOI: 10.1186/1475-925x-7-21] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Accepted: 07/11/2008] [Indexed: 11/10/2022] Open
Abstract
Background One of the current shortcomings of radiofrequency (RF) tumor ablation is its limited performance in regions close to large blood vessels, resulting in high recurrence rates at these locations. Computer models have been used to determine tissue temperatures during tumor ablation procedures. To simulate large vessels, either constant wall temperature or constant convective heat transfer coefficient (h) have been assumed at the vessel surface to simulate convection. However, the actual distribution of the temperature on the vessel wall is non-uniform and time-varying, and this feature makes the convective coefficient variable. Methods This paper presents a realistic time-varying model in which h is a function of the temperature distribution at the vessel wall. The finite-element method (FEM) was employed in order to model RF hepatic ablation. Two geometrical configurations were investigated. The RF electrode was placed at distances of 1 and 5 mm from a large vessel (10 mm diameter). Results When the ablation procedure takes longer than 1–2 min, the attained coagulation zone obtained with both time-varying h and constant h does not differ significantly. However, for short duration ablation (5–10 s) and when the electrode is 1 mm away from the vessel, the use of constant h can lead to errors as high as 20% in the estimation of the coagulation zone. Conclusion For tumor ablation procedures typically lasting at least 5 min, this study shows that modeling the heat sink effect of large vessels by applying constant h as a boundary condition will yield precise results while reducing computational complexity. However, for other thermal therapies with shorter treatment using a time-varying h may be necessary.
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Affiliation(s)
- Icaro dos Santos
- Department of Electrical Engineering, University of Brasilia, Brasilia, DF 70910-900, Brazil.
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Horng TL, Lin WL, Liauh CT, Shih TC. Effects of pulsatile blood flow in large vessels on thermal dose distribution during thermal therapy. Med Phys 2007; 34:1312-20. [PMID: 17500462 DOI: 10.1118/1.2712415] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The aim of this study is to evaluate the effect of pulsatile blood flow in thermally significant blood vessels on the thermal lesion region during thermal therapy of tumor. A sinusoidally pulsatile velocity profile for blood flow was employed to simulate the cyclic effect of the heart beat on the blood flow. The evolution of temperature field was governed by the energy transport equation for blood flow together with Pennes' bioheat equation for perfused tissue encircling the blood vessel. The governing equations were numerically solved by a novel multi-block Chebyshev pseudospectral method and the accumulated thermal dose in tissue was computed. Numerical results show that pulsatile velocity profile, with various combinations of pulsatile amplitude and frequency, has little difference in effect on the thermal lesion region of tissue compared with uniform or parabolic velocity profile. However, some minor differences on the thermal lesion region of blood vessel is observed for middle-sized blood vessel. This consequence suggests that, in this kind of problem, we may as well do the simulation simply by a steady uniform velocity profile for blood flow.
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Affiliation(s)
- Tzyy-Leng Horng
- Department of Applied Mathematics, Feng Chia University, Taichung, Taiwan
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Jacobsen S, Stauffer PR. Can we settle with single-band radiometric temperature monitoring during hyperthermia treatment of chestwall recurrence of breast cancer using a dual-mode transceiving applicator? Phys Med Biol 2007; 52:911-28. [PMID: 17264361 DOI: 10.1088/0031-9155/52/4/004] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The total thermal dose that can be delivered during hyperthermia treatments is frequently limited by temperature heterogeneities in the heated tissue volume. Reliable temperature information on the heated area is thus vital for the optimization of clinical dosimetry. Microwave radiometry has been proposed as an accurate, quick and painless temperature sensing technique for biological tissue. Advantages include the ability to sense volume-averaged temperatures from subsurface tissue non-invasively, rather than with a limited set of point measurements typical of implanted temperature probes. We present a procedure to estimate the maximum tissue temperature from a single radiometric brightness temperature which is based on a numerical simulation of 3D tissue temperature distributions induced by microwave heating at 915 MHz. The temperature retrieval scheme is evaluated against errors arising from unknown variations in thermal, electromagnetic and design model parameters. Whereas realistic deviations from base values of dielectric and thermal parameters have only marginal impact on performance, pronounced deviations in estimated maximum tissue temperature are observed for unanticipated variations of the temperature or thickness of the bolus compartment. The need to pay particular attention to these latter applicator construction parameters in future clinical implementation of the thermometric method is emphasized.
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Affiliation(s)
- Svein Jacobsen
- Electrical Engineering Group, Department of Physics and Technology, Faculty of Science, University of Tromsø, N-9037 Tromsø, Norway.
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McCreedy ES, Cheng R, Hemler PF, Viswanathan A, Wood BJ, McAuliffe MJ. Radio frequency ablation registration, segmentation, and fusion tool. ACTA ACUST UNITED AC 2006; 10:490-6. [PMID: 16871716 PMCID: PMC2614074 DOI: 10.1109/titb.2006.872076] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The radio frequency ablation segmentation tool (RFAST) is a software application developed using the National Institutes of Health's medical image processing analysis and visualization (MIPAV) API for the specific purpose of assisting physicians in the planning of radio frequency ablation (RFA) procedures. The RFAST application sequentially leads the physician through the steps necessary to register, fuse, segment, visualize, and plan the RFA treatment. Three-dimensional volume visualization of the CT dataset with segmented three dimensional (3-D) surface models enables the physician to interactively position the ablation probe to simulate burns and to semimanually simulate sphere packing in an attempt to optimize probe placement. This paper describes software systems contained in RFAST to address the needs of clinicians in planning, evaluating, and simulating RFA treatments of malignant hepatic tissue.
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Affiliation(s)
- Evan S McCreedy
- Center for Information Technology, National Institutes of Health, Bethesda, MD 20892, USA.
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Berjano EJ. Theoretical modeling for radiofrequency ablation: state-of-the-art and challenges for the future. Biomed Eng Online 2006; 5:24. [PMID: 16620380 PMCID: PMC1459161 DOI: 10.1186/1475-925x-5-24] [Citation(s) in RCA: 177] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Accepted: 04/18/2006] [Indexed: 01/09/2023] Open
Abstract
Radiofrequency ablation is an interventional technique that in recent years has come to be employed in very different medical fields, such as the elimination of cardiac arrhythmias or the destruction of tumors in different locations. In order to investigate and develop new techniques, and also to improve those currently employed, theoretical models and computer simulations are a powerful tool since they provide vital information on the electrical and thermal behavior of ablation rapidly and at low cost. In the future they could even help to plan individual treatment for each patient. This review analyzes the state-of-the-art in theoretical modeling as applied to the study of radiofrequency ablation techniques. Firstly, it describes the most important issues involved in this methodology, including the experimental validation. Secondly, it points out the present limitations, especially those related to the lack of an accurate characterization of the biological tissues. After analyzing the current and future benefits of this technique it finally suggests future lines and trends in the research of this area.
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Affiliation(s)
- Enrique J Berjano
- Center for Research and Innovation on Bioengineering, Valencia Polytechnic University, Camino de Vera s/n, 46022 Valencia, Spain.
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