title: A thermochromic dispersive electrode can measure the underlying skin temperature and prevent burns during radiofrequency ablation.
abstract: Evaluation of a thermochromic dispersive electrode.
  
  
  BACKGROUND
  Burns at the dispersive electrode are serious complications of diathermy and radiofrequency (RF) ablation procedures. We aimed to create a new methodology to reduce the incidence of dispersive electrode related skin burns. We hypothesized that a dispersive electrode incorporating a thermochromic liquid crystal (TLC) layer could accurately measure underlying skin temperatures and help prevent burns.
  
  
  RESULTS
  The TLC electrode was compared with a standard dispersive electrode in 12 male sheep. RF current was delivered with the dispersive electrode fully applied or partially detached to simulate different clinical scenarios. The temperature of the TLC layer, calculated from the hue (color) every 15 seconds, was compared with fluoroptic skin temperature probes. TLC electrodes with a temperature range of 45-58 degrees C were used in six sheep to assess the correlation of TLC temperature distribution with skin temperature and burns. TLC electrodes with a temperature range of 40-50 degrees C were used in another 6 sheep to simulate clinical conditions in which the ablation was stopped if the TLC temperature was >42 degrees C. The TLC measured temperatures correlated well with fluoroptic probes at the skin surface (r=0.94+/-0.05, mean of the absolute difference in temperature difference 0.9+/-0.58 degrees C). Ablations with partial application of standard dispersive electrodes consistently caused skin burns. There were no burns under the TLC electrode when ablations were ceased for temperatures>42 degrees C.
  
  
  CONCLUSIONS
  TLC-equipped dispersive electrodes were able to accurately measure skin temperature under the electrode. This technology is likely to prevent dispersive electrode related burns.
authors.affiliation: Department of Cardiology, Westmead Hospital, Westmead, Australia. aravinda@westgate.wh.usyd.edu.au
authors.forename: Aravinda
authors.initials: A
authors.lastname: Thiagalingam
authors.forename: Jim
authors.initials: J
authors.lastname: Pouliopoulos
authors.forename: Michael Anthony Tony
authors.initials: MA
authors.lastname: Barry
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Salisbury
authors.forename: Nirmala
authors.initials: N
authors.lastname: Pathmanathan
authors.forename: Anita
authors.initials: A
authors.lastname: Boyd
authors.forename: David L
authors.initials: DL
authors.lastname: Ross
authors.forename: Pramesh
authors.initials: P
authors.lastname: Kovoor
mesh_terms: D000818:Animals; D002056:Burns / Q000209:etiology* / Q000473:pathology / Q000517:prevention & control*; D017115:Catheter Ablation / Q000009:adverse effects*; D004566:Electrodes / Q000592:standards; D008297:Male; D012756:Sheep; D012867:Skin / Q000293:injuries* / Q000473:pathology; D012881:Skin Temperature