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Wu C, Huang H, Liu Y, Chen L, Yu S, Moser MAJ, Zhang W, Fang Z, Zhang B. Optimal design of aperiodic tri-slot antennas for the conformal ablation of liver tumors using an experimentally validated MWA computer model. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2023; 242:107799. [PMID: 37703699 DOI: 10.1016/j.cmpb.2023.107799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 09/03/2023] [Accepted: 09/03/2023] [Indexed: 09/15/2023]
Abstract
OBJECTIVE This study aims to demonstrate that the conformal microwave ablation (MWA) of liver tumors could be attained by optimizing the structure of an aperiodic tri-slot coaxial antenna, its insertion depth, and input power. METHODS A computational MWA model with an aperiodic tri-slot coaxial antenna operating at the frequency of 2.45 GHz was built and validated by both an ex vivo and a pilot in vivo experiment with porcine healthy livers. The validated in vivo computational MWA model implemented with a liver tumor was then used as a testbed to investigate the conformal ablation of liver tumors. Five liver tumors in different sizes and shapes were investigated. A genetic algorithm optimization method (NSGA-II) was used to optimize the structure of antenna, insertion depth of antenna, and microwave antenna input power for the conformal ablation of liver tumors. RESULTS The validation results showed that a good agreement in both the spatiotemporal temperature distribution and ablation zone was found between the computer model and the ex vivo experiments at both 45 W, 5 min and 60 W, 3 min treatments and the in vivo experiment at 45 W, 5 min treatment. The optimized simulation results confirmed that five cases of liver tumors in different sizes and shapes can be conformally ablated by optimizing the aperiodic tri-slot coaxial antenna, antenna insertion depth, and microwave antenna input power. CONCLUSION This paper demonstrates that the aperiodic tri-slot coaxial antenna can be optimized with the insertion depth and input power for the conformal ablation of liver tumors, regardless the size and shape of liver tumors.
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Affiliation(s)
- Chen Wu
- Intelligent Energy-based Tumor Ablation Laboratory, School of Mechatronic Engineering and Automation, Shanghai University, Shanghai 200444, China
| | - Hangming Huang
- Intelligent Energy-based Tumor Ablation Laboratory, School of Mechatronic Engineering and Automation, Shanghai University, Shanghai 200444, China
| | - Yongfang Liu
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201412, China
| | - Lingchao Chen
- Department of Neurosurgery, Huashan Hospital Shanghai Medical College, Fudan University, Shanghai 200040, China
| | - Shuangquan Yu
- Department of Neurosurgery, Huashan Hospital Shanghai Medical College, Fudan University, Shanghai 200040, China
| | - Michael A J Moser
- Department of Surgery, University of Saskatchewan, Saskatoon, Canada
| | - Wenjun Zhang
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada
| | - Zheng Fang
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada.
| | - Bing Zhang
- Intelligent Energy-based Tumor Ablation Laboratory, School of Mechatronic Engineering and Automation, Shanghai University, Shanghai 200444, China.
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Moll X, Fondevila D, García-Arnas F, Burdio F, Trujillo M, Irastorza RM, Berjano E, Andaluz A. Comparison of two radiofrequency-based hemostatic devices: saline-linked bipolar vs. cooled-electrode monopolar. Int J Hyperthermia 2022; 39:1397-1407. [DOI: 10.1080/02656736.2022.2140840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Xavier Moll
- Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Barcelona, Spain
- Fundació Hospital Clínic Veterinari, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Dolors Fondevila
- Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Félix García-Arnas
- Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Fernando Burdio
- Department of Surgery, Division of Hepato-Biliary and Pancreatic Surgery, Hospital del Mar, Barcelona, Spain; Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
| | - Macarena Trujillo
- Department of Applied Mathematics, BioMIT, Universitat Politècnica de València, Valencia, Spain
| | - Ramiro M. Irastorza
- Instituto de Física de Líquidos y Sistemas Biológicos (CONICET), La Plata, Argentina
- Departamento de Ingeniería Mecánica, Universidad Tecnológica Nacional, Facultad Regional La Plata, La Plata, Argentina
| | - Enrique Berjano
- Department of Electronic Engineering, BioMIT, Universitat Politècnica de València, Valencia, Spain
| | - Anna Andaluz
- Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Barcelona, Spain
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Cao Z, Li J, Fang Z, Feierkaiti Y, Zheng X, Jiang X. The factors influencing the efficiency of drug-coated balloons. Front Cardiovasc Med 2022; 9:947776. [PMCID: PMC9602405 DOI: 10.3389/fcvm.2022.947776] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 08/26/2022] [Indexed: 11/13/2022] Open
Abstract
The drug-coated balloon (DCB) is an emerging percutaneous coronary intervention (PCI) device that delivers drugs to diseased vessels to decrease the rate of vascular stenosis. Recent clinical studies have demonstrated that DCBs tend to have both good safety and efficacy profiles, leading to extended application indications in the clinic, including in-stent restenosis (ISR) for metal stents such as drug-eluting stents (DESs), small vascular disease, bifurcation disease, large vascular disease, acute coronary syndrome (ACS), and high bleeding risk. However, some previous clinical data have suggested that DCBs performed less effectively than DESs. No studies or reviews have systematically discussed the improvement strategies for better DCB performance until now. Drug loss during the process of delivery to the target lesion and inefficient delivery of the coating drug to the diseased vascular wall are two key mechanisms that weaken the efficiency of DCBs. This review is the first to summarize the key influencing factors of DCB efficiency in terms of balloon structure and principles, and then it analyzes how these factors cause outcomes in practice based on current clinical trial studies of DCBs in the treatment of different types of lesions. We also provide some recommendations for improving DCBs to contribute to better DCB performance by improving the design of DCBs and combining other factors in clinical practice.
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Affiliation(s)
- Zheng Cao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China,Cardiovascular Research Institute, Wuhan University, Wuhan, Hubei, China,Hubei Key Laboratory of Cardiology, Wuhan, Hubei, China
| | - Jun Li
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China,Cardiovascular Research Institute, Wuhan University, Wuhan, Hubei, China,Hubei Key Laboratory of Cardiology, Wuhan, Hubei, China
| | - Zhao Fang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China,Cardiovascular Research Institute, Wuhan University, Wuhan, Hubei, China,Hubei Key Laboratory of Cardiology, Wuhan, Hubei, China
| | - Yushanjiang Feierkaiti
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China,Cardiovascular Research Institute, Wuhan University, Wuhan, Hubei, China,Hubei Key Laboratory of Cardiology, Wuhan, Hubei, China
| | - Xiaoxin Zheng
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China,Cardiovascular Research Institute, Wuhan University, Wuhan, Hubei, China,Hubei Key Laboratory of Cardiology, Wuhan, Hubei, China,*Correspondence: Xiaoxin Zheng,
| | - Xuejun Jiang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China,Cardiovascular Research Institute, Wuhan University, Wuhan, Hubei, China,Hubei Key Laboratory of Cardiology, Wuhan, Hubei, China,Xuejun Jiang,
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Chang CF, Kuo HY, Lee JP. AC measurements and simulations of hepatic radiofrequency ablation. Int J Hyperthermia 2021; 38:1322-1332. [PMID: 34477032 DOI: 10.1080/02656736.2021.1971779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
INTRODUCTION The radiofrequency ablation (RFA) of liver cancer is a desirable treatment option, as it is minimally invasive. An accurate numerical simulation can greatly help physicians better plan their surgical protocols. Previously, the displacement current in the RFA process was considered negligible, and therefore RFA simulation was modeled as a direct current (DC) system instead of an alternating current (AC) system. Our study investigated the hypothesis that the displacement current in the RFA process should not always be considered negligible. METHODS AC measurements of ex vivo bovine liver ablation were performed, and numerical simulations were also conducted to test the hypothesis that the relative permittivity would significantly decrease after the liver tissue reached a high temperature. RESULTS The displacement current was observed to be a sizable fraction of the conduction current, especially before the onset of the first pause. The simulation results indicated that the relative permittivity is likely to decrease to several hundred or lower at elevated temperatures. CONCLUSIONS Our study results suggest that the DC model may be inadequate, especially before the first roll-off and that additional information could be available during RFA treatment by considering the AC nature of RFA, which could lead to improved numerical simulation. Additional measurements of tissue parameters are needed to reach the full potential of the AC model for further development of ablation control.
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Affiliation(s)
- Chieh-Feng Chang
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Chutung, Taiwan
| | - Hsuan-Yu Kuo
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Chutung, Taiwan
| | - Jo-Ping Lee
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Chutung, Taiwan
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Yan S, Gu K, Wu X, Wang W. Computer simulation study on the effect of electrode-tissue contact force on thermal lesion size in cardiac radiofrequency ablation. Int J Hyperthermia 2020; 37:37-48. [PMID: 31918588 DOI: 10.1080/02656736.2019.1708482] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Purpose: In cardiac radiofrequency (RF) ablation, RF energy is often used to create a series of transmural lesions for blocking accessory conduction pathways. Electrode-tissue contact force (CF) is one of the key determinants of lesion formation during RF ablation. Low electrode-tissue CF is associated with ineffective RF lesion formation, whereas excessive CF may increase the risk of steam pop and perforation. By using finite element analysis, we studied lesion size and features at different values of electrode-tissue CF in cardiac RF ablation.Materials and methods: A computer-model-coupled electrode-tissue CF field, RF electric field, and thermal field were developed to study temperature distribution and lesion dimensions in cardiac tissue subjected to CF of 2, 5, 10, 20, 30, and 40 g with identical RF voltage and duration.Results: Increasing CF was associated with an increase in lesion depth, width, and cross-section area. The lesion cross-section area exhibited a linear increase, and the lesion width was significantly greater than lesion depth under the identical ablation condition. The relationship between CF value and lesion size is a power function: Lesion Size = a × CFb (Lesion Depth = 3.17 × CF0.14 and Lesion Width = 5.17 × CF0.14).Conclusions: This study confirmed that CF is a major determinant of RF lesion size and that electrode-tissue CF affects the amount of power dissipated in tissue. At a constant RF voltage and application time, RF lesion size increases as CF increases.
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Affiliation(s)
- Shengjie Yan
- Electronic Engineering Department, Fudan University, Shanghai, China
| | - Kaihao Gu
- Electronic Engineering Department, Fudan University, Shanghai, China
| | - Xiaomei Wu
- Electronic Engineering Department, Fudan University, Shanghai, China.,Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention (MICCAI) of Shanghai, Fudan University, Shanghai, China.,Shanghai Engineering Research Center of Assistive Devices, Shanghai, China
| | - Weiqi Wang
- Electronic Engineering Department, Fudan University, Shanghai, China
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A review of radiofrequency ablation: Large target tissue necrosis and mathematical modelling. Phys Med 2016; 32:961-71. [PMID: 27461969 DOI: 10.1016/j.ejmp.2016.07.092] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Revised: 06/06/2016] [Accepted: 07/18/2016] [Indexed: 12/15/2022] Open
Abstract
Radiofrequency ablation (RFA) is an effective clinical method for tumour ablation with minimum intrusiveness. However, the use of RFA is mostly restricted to small tumours, especially those <3cm in diameter. This paper discusses the state-of-the-art of RFA, drawn from experimental and clinical results, for large tumours (i.e. ⩾3cm in diameter). In particular, the paper analyses clinical results related to target tissue necrosis (TTN) and mathematical modelling of the RFA procedure to understand the mechanism whereby the TTN is limited to under 3cm with RFA. This paper also discusses a strategy of controlling of the temperature of target tissue in the RFA procedure with the state-of-art device, which has the potential to increase the size of TTN. This paper ends with a discussion of some future ideas to solve the so-called 3-cm problem with RFA.
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Trujillo M, Bon J, José Rivera M, Burdío F, Berjano E. Computer modelling of an impedance-controlled pulsing protocol for RF tumour ablation with a cooled electrode. Int J Hyperthermia 2016; 32:931-939. [PMID: 27452352 DOI: 10.1080/02656736.2016.1190868] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
PURPOSE To develop computer models to mimic the impedance-controlled pulsing protocol implemented in radiofrequency (RF) generators used for clinical practice of radiofrequency ablation (RFA), and to assess the appropriateness of the models by comparing the computer results with those obtained in previous experimental studies. METHODS A 12-min RFA was modelled using a cooled electrode (17G, 3 cm tip) inserted in hepatic tissue. The short (transverse) diameter of the coagulation zone was assessed under in vivo (with blood perfusion (BP) and considering clamping) and ex vivo (at 21 °C) conditions. The computer results obtained by programming voltage pulses were compared with current pulses. RESULTS The differences between voltage and current pulses were noticeable: using current instead of voltage allows larger coagulation zones to be created, due to the higher energy applied by current pulses. If voltage pulses are employed the model can accurately predict the number of roll-offs, although the waveform of the applied power is clearly not realistic. If current voltages are employed, the applied power waveform matches well with those reported experimentally, but there are significantly fewer roll-offs. Our computer results were overall into the ranges of experimental ones. CONCLUSIONS The proposed models reproduce reasonably well the electrical-thermal performance and coagulation zone size obtained during an impedance-controlled pulsing protocol.
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Affiliation(s)
- Macarena Trujillo
- a Instituto Universitario de Matemática Pura y Aplicada, Universitat Politècnica de València , Spain
| | - Jose Bon
- b Food Technology Department , Universitat Politècnica de València , Spain
| | - María José Rivera
- c Applied Mathematics Department , Universitat Politècnica de València , Spain
| | - Fernando Burdío
- d Department of Surgery , Hospital del Mar , Barcelona , Spain
| | - Enrique Berjano
- e Biomedical Synergy, Department of Electronic Engineering , Universitat Politècnica de València , Spain
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