Real-time temperature control system based on the finite element method for liver radiofrequency ablation: effect of the time interval on control

Yosuke Isobe, Hiroki Watanabe, Nozomu Yamazaki, Xiao Wei Lu, Yo Kobayashi, Tomoyuki Miyashita, Makoto Hashizume, Masakatsu G. Fujie

Research output: Contribution to journalArticle

Abstract

Radiofrequency (RF) ablation is increasingly being used to treat liver cancer because it is minimally invasive. However, it is difficult for operators to control the size of the coagulation zones precisely, because no method has been established to form an adequate and suitable ablation area. To overcome this limitation, we propose a new system that can control the coagulation zone size. The system operates as follows: 1) the liver temperature is estimated using a temperature-distribution simulator to reduce invasiveness; 2) the output power of the RF generator is controlled automatically according to the liver temperature. To use this system in real time, both the time taken to calculate the temperature in the simulation and the control accuracy are important. We therefore investigated the relationship between the time interval required to change the output voltage and temperature control stability in RF ablation. The results revealed that the proposed method can control the temperature at a point away from the electrode needle to obtain the desired ablation size. It was also shown to be necessary to reduce the time interval when small tumors are cauterized to avoid excessive treatment. In contrast, such high frequency feedback control is not required when large tumors are cauterized.

Fingerprint

Real time control
Ablation
Temperature control
Liver
Control systems
Finite element method
Temperature
Coagulation
Tumors
Needles
Voltage control
Feedback control
Temperature distribution
Simulators
Computer Systems
Liver Neoplasms
Electrodes
Neoplasms

All Science Journal Classification (ASJC) codes

  • Signal Processing
  • Biomedical Engineering
  • Computer Vision and Pattern Recognition
  • Health Informatics

Cite this

Real-time temperature control system based on the finite element method for liver radiofrequency ablation : effect of the time interval on control. / Isobe, Yosuke; Watanabe, Hiroki; Yamazaki, Nozomu; Lu, Xiao Wei; Kobayashi, Yo; Miyashita, Tomoyuki; Hashizume, Makoto; Fujie, Masakatsu G.

In: Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, Vol. 2013, 2013, p. 392-396.

Research output: Contribution to journalArticle

@article{e644233d5d144c14aa2d2c81b42b01c5,
title = "Real-time temperature control system based on the finite element method for liver radiofrequency ablation: effect of the time interval on control",
abstract = "Radiofrequency (RF) ablation is increasingly being used to treat liver cancer because it is minimally invasive. However, it is difficult for operators to control the size of the coagulation zones precisely, because no method has been established to form an adequate and suitable ablation area. To overcome this limitation, we propose a new system that can control the coagulation zone size. The system operates as follows: 1) the liver temperature is estimated using a temperature-distribution simulator to reduce invasiveness; 2) the output power of the RF generator is controlled automatically according to the liver temperature. To use this system in real time, both the time taken to calculate the temperature in the simulation and the control accuracy are important. We therefore investigated the relationship between the time interval required to change the output voltage and temperature control stability in RF ablation. The results revealed that the proposed method can control the temperature at a point away from the electrode needle to obtain the desired ablation size. It was also shown to be necessary to reduce the time interval when small tumors are cauterized to avoid excessive treatment. In contrast, such high frequency feedback control is not required when large tumors are cauterized.",
author = "Yosuke Isobe and Hiroki Watanabe and Nozomu Yamazaki and Lu, {Xiao Wei} and Yo Kobayashi and Tomoyuki Miyashita and Makoto Hashizume and Fujie, {Masakatsu G.}",
year = "2013",
doi = "10.1109/EMBC.2013.6609519",
language = "English",
volume = "2013",
pages = "392--396",
journal = "Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings",
issn = "1557-170X",
publisher = "Institute of Electrical and Electronics Engineers Inc.",

}

TY - JOUR

T1 - Real-time temperature control system based on the finite element method for liver radiofrequency ablation

T2 - effect of the time interval on control

AU - Isobe, Yosuke

AU - Watanabe, Hiroki

AU - Yamazaki, Nozomu

AU - Lu, Xiao Wei

AU - Kobayashi, Yo

AU - Miyashita, Tomoyuki

AU - Hashizume, Makoto

AU - Fujie, Masakatsu G.

PY - 2013

Y1 - 2013

N2 - Radiofrequency (RF) ablation is increasingly being used to treat liver cancer because it is minimally invasive. However, it is difficult for operators to control the size of the coagulation zones precisely, because no method has been established to form an adequate and suitable ablation area. To overcome this limitation, we propose a new system that can control the coagulation zone size. The system operates as follows: 1) the liver temperature is estimated using a temperature-distribution simulator to reduce invasiveness; 2) the output power of the RF generator is controlled automatically according to the liver temperature. To use this system in real time, both the time taken to calculate the temperature in the simulation and the control accuracy are important. We therefore investigated the relationship between the time interval required to change the output voltage and temperature control stability in RF ablation. The results revealed that the proposed method can control the temperature at a point away from the electrode needle to obtain the desired ablation size. It was also shown to be necessary to reduce the time interval when small tumors are cauterized to avoid excessive treatment. In contrast, such high frequency feedback control is not required when large tumors are cauterized.

AB - Radiofrequency (RF) ablation is increasingly being used to treat liver cancer because it is minimally invasive. However, it is difficult for operators to control the size of the coagulation zones precisely, because no method has been established to form an adequate and suitable ablation area. To overcome this limitation, we propose a new system that can control the coagulation zone size. The system operates as follows: 1) the liver temperature is estimated using a temperature-distribution simulator to reduce invasiveness; 2) the output power of the RF generator is controlled automatically according to the liver temperature. To use this system in real time, both the time taken to calculate the temperature in the simulation and the control accuracy are important. We therefore investigated the relationship between the time interval required to change the output voltage and temperature control stability in RF ablation. The results revealed that the proposed method can control the temperature at a point away from the electrode needle to obtain the desired ablation size. It was also shown to be necessary to reduce the time interval when small tumors are cauterized to avoid excessive treatment. In contrast, such high frequency feedback control is not required when large tumors are cauterized.

UR - http://www.scopus.com/inward/record.url?scp=84938097083&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84938097083&partnerID=8YFLogxK

U2 - 10.1109/EMBC.2013.6609519

DO - 10.1109/EMBC.2013.6609519

M3 - Article

C2 - 24109706

VL - 2013

SP - 392

EP - 396

JO - Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings

JF - Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings

SN - 1557-170X

ER -