title: Comparison of blade temperature dynamics after activation of Harmonic Ace scalpel and the Ultracision Harmonic Scalpel LCS-K5.
abstract: OBJECTIVE
  To compare tip temperatures of the vibrating blades of the newer-generation Harmonic Ace device and the older-generation Ultracision Harmonic Scalpel LCS-K5.
  
  
  METHODS
  Comparison of two different harmonic scalpel blades was performed by applying them to 3-mm strips of raw chicken breast at room temperature and measuring the temperature of the tip of the vibrating blade at 0.5-second intervals using a thermocouple. Following activation, the tip was allowed to passively cool to 30 degrees C each time before reactivation. Each device was tested at power settings of 3 and 5 after activation for 1 to 5 seconds. All measurements were performed 5 times.
  
  
  RESULTS
  Compared to the older-generation Ultracision Harmonic Scalpel LCS-K5, the newer-generation Harmonic Ace was associated with higher tip temperatures at power level 5 at all times of activation (1-5 seconds), and at power level 3 at longer times of activation (3-5 seconds). The Harmonic Ace also takes longer to reach peak temperatures and can maintain blade hyperthermia for a longer period after activation for more than 3 seconds at power levels 3 and 5.
  
  
  CONCLUSIONS
  The newer-generation Harmonic Ace may be potentially more effective in tissue dissection, but is associated with greater increases in peak temperatures and longer blade hyperthermia periods compared to the older-generation Ultracision Harmonic Scalpel LCS-K5. The difference is greater after longer periods of activation, and this may have more potential for collateral damage, particularly to nerves and bowel.
authors.affiliation: Division of Urology, Department of Surgery, University of Wisconsin, Madison, Wisconsin, USA.
authors.forename: Gaurav
authors.initials: G
authors.lastname: Bandi
authors.forename: Charles C
authors.initials: CC
authors.lastname: Wen
authors.forename: Eric A
authors.initials: EA
authors.lastname: Wilkinson
authors.forename: Sean P
authors.initials: SP
authors.lastname: Hedican
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Moon
authors.forename: Stephen Y
authors.initials: SY
authors.lastname: Nakada
mesh_terms: D000818:Animals; D002645:Chickens; D004210:Dissection / Q000295:instrumentation*; D004867:Equipment Design; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D015203:Reproducibility of Results; D013696:Temperature; D014464:Ultrasonic Therapy / Q000295:instrumentation*