Finite element analysis predicts dose-response relationship for constant power and temperature controlled radiofrequencg ablation

Jain, M.K.; Wolf, Patrick D.

doi:10.1109/iembs.1997.754493

Cited by 11 publications

(16 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, the usual practice is to model a constant-temperature RF ablation, in which the delivered electrical power is modulated by the RF generator to maintain at a preset value the temperature of a sensor located in the electrode. In this case, a boundary condition of fixed voltage on the active electrode is used, but its value is adjusted to keep the sensor temperature constant [ 14 , 16 , 29 , 31 , 32 , 34 , 36 , 37 , 42 , 43 , 45 , 46 , 50 , 51 , 53 ]. This procedure involves manual adjustment based on a costly trial-and-error method.…”

Section: Description Of Methodologymentioning

confidence: 99%

“…In this respect, a closed loop control joined to the theoretical model allows not only a temperature controlled RF ablation to be modeled with minimal user input, but also gives results comparable to clinical devices that use this type of control [ 33 , 69 ]. Other studies also modeled constant-power ablation [ 14 , 32 , 42 , 43 , 70 ], which is a clinically employed procedure. Finally, some models included ablation with controlled impedance mode, i.e.…”

Section: Description Of Methodologymentioning

confidence: 99%

“…Thermal conditions can be of two types: 1) null thermal flux (Neumann boundary condition), for instance, at the symmetry axis and plane [ 17 , 52 ]; 2) constant temperature (Dirichlet boundary condition) for instance, at points distant from the heated zone [ 17 , 24 , 27 , 42 , 48 , 49 , 71 ], at the same active electrode used to model an internally cooled electrode [ 41 , 68 ], and 3) thermal convection (forced or free) modeled by means of a thermal transfer coefficient, e.g. at the air-tissue interface [ 17 , 25 , 48 , 49 , 52 ], and the endothelium-blood interface in cardiac chambers [ 24 , 25 , 27 , 45 ].…”

Section: Description Of Methodologymentioning

confidence: 99%

See 2 more Smart Citations

Theoretical modeling for radiofrequency ablation: state-of-the-art and challenges for the future

2006

View full text Add to dashboard Cite

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.

show abstract

Section: Description Of Methodologymentioning

confidence: 99%

Section: Description Of Methodologymentioning

confidence: 99%

Section: Description Of Methodologymentioning

confidence: 99%

See 1 more Smart Citation

Theoretical modeling for radiofrequency ablation: state-of-the-art and challenges for the future

2006

View full text Add to dashboard Cite

show abstract

“…Several studies have been conducted to describe lesion growth for radiofrequency ablation devices [2,[9][10][11][12]21,24,[29][30][34][35]. In the majority of these cases, markers such as temperature isotherms and thermal dosing are used as the primary measure for lesion size.…”

Section: Discussionmentioning

confidence: 99%

Considerations for Thermal Injury Analysis for RF Ablation Devices

Chang¹

2010

TOBEJ

View full text Add to dashboard Cite

Abstract:Background: The estimation of lesion size is an integral part of treatment planning for the clinical applications of radiofrequency ablation. However, to date, studies have not directly evaluated the impact of different computational estimation techniques for predicting lesion size. In this study, we focus on three common methods used for predicting tissue injury: (1) iso-temperature contours, (2) Cumulative equivalent minutes, (3) Arrhenius based thermal injury. Methods:We created a geometric model of a multi-tyne ablation electrode and simulated thermal and tissue injury profiles that result from three calculation methods after 15 minutes exposure to a constant RF voltage source. A hybrid finite element technique was used to calculate temperature and tissue injury. Time-temperature curves were used in the assessment of iso-temperature thresholds and the method of cumulative equivalent minutes. An Arrhenius-based formulation was used to calculate sequential and recursive thermal injury to tissues. Results: The data demonstrate that while iso-temperature and cumulative equivalent minute contours are similar in shape, these two methodologies grossly over-estimate the amount of tissue injury when compared to recursive thermal injury calculations, which have previously been shown to correlate closely with in vitro pathologic lesion volume measurement. In addition, Arrhenius calculations that do not use a recursive algorithm result in a significant underestimation of lesion volume. The data also demonstrate that lesion width and depth are inadequate means of characterizing treatment volume for multi-tine ablation devices. Conclusions: Recursive thermal injury remains the most physiologically relevant means of computationally estimating lesion size for hepatic tumor applications. Iso-thermal and cumulative equivalent minute approaches may produce significant errors in the estimation of lesion size.

show abstract

“…The temperature elevation history can then be used to assess thermal damage. Many researchers have been utilising temperature thresholds to predict lesion size and to define thermal injury [9][10][11][12][13][14][15]. The most common temperature thresholds assigned are 43 C, 48 C, 50 C, and 60 C [16][17][18][19][20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Development of a computational simulation tool to design a protocol for treating prostate tumours using transurethral laser photothermal therapy

Manuchehrabadi

Zhu

2014

International Journal of Hyperthermia

View full text Add to dashboard Cite

Heating time to achieve 100% damage to the tumour was identified to be approximately 630 s when using a laser irradiance of 7 W/cm2 incident on the prostatic urethral surface. Parametric studies were conducted to show how the local blood perfusion rate and urethral surface cooling affect the heating time to achieve the same thermal dosage. The heating time was shorter when cooling at the urethra was not applied and/or with heat-induced vasculature damage. The identified treatment protocols were acceptable since the calculated percentages of the damaged healthy tissue volume to the healthy prostatic volume were approximately 2%, less than the threshold of 5%. The approach and results from this study can be used to design individualised treatment protocols for patients suffering from prostatic cancer.

show abstract

Finite element analysis predicts dose-response relationship for constant power and temperature controlled radiofrequencg ablation

Cited by 11 publications

References 10 publications

Theoretical modeling for radiofrequency ablation: state-of-the-art and challenges for the future

Theoretical modeling for radiofrequency ablation: state-of-the-art and challenges for the future

Considerations for Thermal Injury Analysis for RF Ablation Devices

Development of a computational simulation tool to design a protocol for treating prostate tumours using transurethral laser photothermal therapy

Contact Info

Product

Resources

About