Modeling of a single bipolar electrode with tines for irreversible electroporation delivery

Objective: To test a new bipolar electrode for electroporation consisting of a single minimally invasive needle. Methods: A theoretical study was performed by using Comsol Multiphysics® software. The prototypes of electrode have been tested on potatoes and pigs, adopting an irreversible electroporation protocol. Different applied voltages and different geometries of bipolar electrode prototype have been evaluated. Results: Simulations and pre-clinical tests have shown that the volume of ablated area is mainly influenced by applied voltage, while the diameter of the electrode had a lesser impact, making the goal of minimal-invasiveness possible. The conductive pole’s length determined an increase of electroporated volume, while the insulated pole length inversely affects the electroporated volume size and shape; when the insulated pole length decreases, a more regular shape of the electric field is obtained. Moreover, the geometry of the electrode determined a different shape of the electroporated volume. A parenchymal damage in the liver of pigs due to irreversible electroporation protocol was observed. Conclusion: The minimally invasive bipolar electrode is able to treat an electroporated volume of about 10 mm in diameter by using a single-needle electrode. Moreover, the geometry and the electric characteristics can be selected to produce ellipsoidal ablation volumes.

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Novel platinum bipolar electrode for irreversible electroporation in prostate cancer: preclinical study in the beagle prostate

Scientific Reports ◽

10.1038/s41598-021-96734-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Bumjin Lim ◽

Hong Bae Kim ◽

Seung Jeong ◽

Song Hee Kim ◽

Jeon Min Kang ◽

...

Keyword(s):

Prostate Cancer ◽

Field Strength ◽

Electric Field ◽

Electric Field Strength ◽

Irreversible Electroporation ◽

Preclinical Study ◽

Bipolar Electrode ◽

The Novel ◽

Monopolar Electrodes ◽

Cancer Ablation

AbstractThe exposure of the prostate to high electric field strength during irreversible electroporation (IRE) has been extensively investigated. Multiple monopolar electrodes, however, have risks of organ piercing and bleeding when placing electrodes. A novel bipolar electrode made of pure platinum and stainless steel was developed for prostate cancer ablation. Voltages of 500 and 700 V were applied to the beagle prostate with this electrode to evaluate ablated tissues and their characteristics. IRE procedures were technically successful in all dogs without procedure-related complications. The current that flowed through the anode and cathode while applying 500 and 700 V were 1.75 ± 0.25 A and 2.22 ± 0.35 A, respectively. TUNEL assays showed that the estimated ablated areas when applying 500 and 700 V were 0.78 cm2 and 1.21 cm2, respectively. The minimum electric field strength threshold required for induction of IRE was 800 V/cm. The platinum electrode was resistant to corrosion. The IRE procedure for beagle prostates using a single bipolar electrode was technically feasible and safe. The novel bipolar electrode has great potential for treating human prostate cancer with fewer IRE-related complications.

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DEVELOPMENT OF NOVEL ENDOSCOPIC IRREVERSIBLE ELECTROPORATION ABLATION DEVICE

10.1055/s-0038-1637298 ◽

2018 ◽

Author(s):

G Min ◽

HS Choi ◽

W Kim ◽

SJ Choi ◽

JM Lee ◽

...

Keyword(s):

Irreversible Electroporation

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Comparison of Irreversible Electroporation and Radical Prostatectomy in Treating Prostate Cancer

Case Medical Research ◽

10.31525/ct1-nct04278261 ◽

2020 ◽

Author(s):

Keyword(s):

Prostate Cancer ◽

Radical Prostatectomy ◽

Irreversible Electroporation

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Accuracy of diffusion tensor magnetic resonance imaging tractography assessed using intraoperative subcortical stimulation mapping and magnetic source imaging

Journal of Neurosurgery ◽

10.3171/jns-07/09/0488 ◽

2007 ◽

Vol 107 (3) ◽

pp. 488-494 ◽

Cited By ~ 158

Author(s):

Jeffrey I. Berman ◽

Mitchel S. Berger ◽

Sungwon Chung ◽

Srikantan S. Nagarajan ◽

Roland G. Henry

Keyword(s):

White Matter ◽

Magnetic Resonance ◽

Diffusion Tensor ◽

Fiber Tracking ◽

Bipolar Electrode ◽

Source Imaging ◽

Magnetic Source Imaging ◽

Motor Pathway ◽

Magnetic Source ◽

Subcortical Stimulation

Object Resecting brain tumors involves the risk of damaging the descending motor pathway. Diffusion tensor (DT)–imaged fiber tracking is a noninvasive magnetic resonance (MR) technique that can delineate the subcortical course of the motor pathway. The goal of this study was to use intraoperative subcortical stimulation mapping of the motor tract and magnetic source imaging to validate the utility of DT-imaged fiber tracking as a tool for presurgical planning. Methods Diffusion tensor-imaged fiber tracks of the motor tract were generated preoperatively in nine patients with gliomas. A mask of the resultant fiber tracks was overlaid on high-resolution T1- and T2-weighted anatomical MR images and used for stereotactic surgical navigation. Magnetic source imaging was performed in seven of the patients to identify functional somatosensory cortices. During resection, subcortical stimulation mapping of the motor pathway was performed within the white matter using a bipolar electrode. Results A total of 16 subcortical motor stimulations were stereotactically identified in nine patients. The mean distance between the stimulation sites and the DT-imaged fiber tracks was 8.7 ±3.1 mm (±standard deviation). The measured distance between subcortical stimulation sites and DT-imaged fiber tracks combines tracking technique errors and all errors encountered with stereotactic navigation. Conclusions Fiber tracks delineated using DT imaging can be used to identify the motor tract in deep white matter and define a safety margin around the tract.

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Faculty Opinions recommendation of Renal tissue ablation with irreversible electroporation: preliminary results in a porcine model.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.11523957.12565055 ◽

2011 ◽

Author(s):

Uri Lindner ◽

Alyssa Louis

Keyword(s):

Porcine Model ◽

Irreversible Electroporation ◽

Renal Tissue ◽

Tissue Ablation ◽

Preliminary Results

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Amplitude cancellation reduces the size of motor unit potentials averaged from the surface EMG

Journal of Applied Physiology ◽

10.1152/japplphysiol.01282.2005 ◽

2006 ◽

Vol 100 (6) ◽

pp. 1928-1937 ◽

Cited By ~ 78

Author(s):

Kevin G. Keenan ◽

Dario Farina ◽

Roberto Merletti ◽

Roger M. Enoka

Keyword(s):

Motor Unit ◽

Conduction Velocity ◽

Motor Units ◽

Surface Emg ◽

Excitation Level ◽

Bipolar Electrode ◽

Emg Signal ◽

Motor Unit Synchronization ◽

Rate Coding ◽

Simulated Surface

The purpose of the study was to evaluate the influence of selected physiological parameters on amplitude cancellation in the simulated surface electromyogram (EMG) and the consequences for spike-triggered averages of motor unit potentials derived from the interference and rectified EMG signals. The surface EMG was simulated from prescribed recruitment and rate coding characteristics of a motor unit population. The potentials of the motor units were detected on the skin over a hand muscle with a bipolar electrode configuration. Averages derived from the EMG signal were generated using the discharge times for each of the 24 motor units with lowest recruitment thresholds from a population of 120 across three conditions: 1) excitation level; 2) motor unit conduction velocity; and 3) motor unit synchronization. The area of the surface-detected potential was compared with potentials averaged from the interference, rectified, and no-cancellation EMGs. The no-cancellation EMG comprised motor unit potentials that were rectified before they were summed, thereby preventing cancellation between the opposite phases of the potentials. The percent decrease in area of potentials extracted from the rectified EMG was linearly related to the amount of amplitude cancellation in the interference EMG signal, with the amount of cancellation influenced by variation in excitation level and motor unit conduction velocity. Motor unit synchronization increased potentials derived from both the rectified and interference EMG signals, although cancellation limited the increase in area for both potentials. These findings document the influence of amplitude cancellation on motor unit potentials averaged from the surface EMG and the consequences for using the procedure to characterize motor unit properties.

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