Computational Analysis of Pulsed Radiofrequency Ablation in Treating Chronic Pain

In this paper, a parametric study has been conducted to evaluate the effects of frequency and duration of the short burst pulses during pulsed radiofrequency ablation (RFA) in treating chronic pain. Affecting the brain and nervous system, this disease remains one of the major challenges in neuroscience and clinical practice. A two-dimensional axisymmetric RFA model has been developed in which a single needle radiofrequency electrode has been inserted. A finite-element-based coupled thermo-electric analysis has been carried out utilizing the simplified Maxwell’s equations and the Pennes bioheat transfer equation to compute the electric field and temperature distributions within the computational domain. Comparative studies have been carried out between the continuous and pulsed RFA to highlight the significance of pulsed RFA in chronic pain treatment. The frequencies and durations of short burst RF pulses have been varied from 1 Hz to 10 Hz and from 10 ms to 50 ms, respectively. Such values are most commonly applied in clinical practices for mitigation of chronic pain. By reporting such critical input characteristics as temperature distributions for different frequencies and durations of the RF pulses, this computational study aims at providing the first-hand accurate quantitative information to the clinicians on possible consequences in those cases where these characteristics are varied during the pulsed RFA procedure. The results demonstrate that the efficacy of pulsed RFA is significantly dependent on the duration and frequency of the RF pulses

Effect of applied voltage, duration and repetition frequency of RF pulses for pain relief on temperature spikes and electrical field: a computer modeling study

Background: The thermal and electrical effects of pulsed radiofrequency (PRF) for pain relief can be controlled by modifying the characteristics of the RF pulses applied. Our goal was to evaluate the influence of such modifications on the thermal and electric performance in tissue. Methods: A computational model was developed to compare the temperature and electric field time courses in tissue between a standard clinical protocol (45 V pulses, 20 ms duration, 2 Hz repetition frequency) and a new protocol (55 V pulses, 5 ms duration, 5 Hz repetition frequency) with a higher applied electric field but a smaller impact on temperature alterations in tissue. The effect of including a temperature controller was assessed. Complementarily, an agar-based experimental model was developed to validate the methodology employed in the computer modeling. Results: The new protocol increased the electric field magnitude reached in the tissue by around +20%, without increasing the temperature. The temperature controller was found to be the fundamental factor in avoiding thermal damage to the tissue and reduced the total number of pulses delivered by around 67%. The experimental results matched moderately well with those obtained from a computer model built especially to mimic the experimental conditions. Conclusions: For the same delivered energy, the new protocol significantly increases the magnitude of the applied electric field, which may be the reason why it is clinically more effective in achieving pain relief