title: Ultrasound heating is curvilinear in nature and varies between transducers from the same manufacturer.
abstract: BACKGROUND
  Ultrasound heating rates are known to differ between various manufacturers; it is unknown whether this difference exists within a manufacturer.
  
  
  OBJECTIVE
  Determine if intramuscular heating differences exist between transducers from the same manufacturer.
  
  
  METHODS
  3 x 10 repeated measures. Independent variables were Transducer (A, B, and C) and Time (10-min time points during the treatment).
  
  
  METHODS
  Controlled laboratory.
  
  
  METHODS
  Twelve volunteers (M = 4, F = 8; age: 23 +/- 4 years; calf-girth: 37.94 +/- 4.16 cm; calf-skinfold: 27 +/- 17 mm).
  
  
  METHODS
  Three 10-min 1MHz continuous ultrasound treatments performed at an intensity of 1.2 W/cm2, over an area 2x transducer.
  
  
  METHODS
  Calf temperature increase.
  
  
  RESULTS
  Heating curve generated for each transducer were significantly different (P = .034) but the overall temperature increases following 10 minutes of treatment were within 0.1 degree C (F = 1.023 P = .573).
  
  
  CONCLUSIONS
  Heating curves differ between transducers from the same manufacturer but peak heating at 10 minutes was similar.
authors.affiliation: Athletic Training Department, Indiana State University, Terre Haute, IN, USA. athdemch@isugw.indstate.edu
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Demchak
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Straub
authors.forename: Lennart D
authors.initials: LD
authors.lastname: Johns
mesh_terms: D000328:Adult; D001831:Body Temperature; D004311:Double-Blind Method; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D014159:Transducers; D014464:Ultrasonic Therapy / Q000295:instrumentation*