title: A flexible pressure sensor could correctly measure the depth of chest compression on a mattress.
abstract: BACKGROUND
  Feedback devices are used to improve the quality of chest compression (CC). However, reports have noted that accelerometers substantially overestimate depth when cardiopulmonary resuscitation (CPR) is performed on a soft surface. Here, we determined whether a flexible pressure sensor could correctly evaluate the depth CC performed on a mannequin placed on a mattress.
  
  
  METHODS
  Chest compression was performed 100 times/min by a compression machine on the floor or a mattress, and the depth of CC was monitored using a flexible pressure sensor (Shinnosukekun) and CPRmeter(™). The depth of machine-performed CC was consistently 5cm. We compared data from the feedback sensor with the true depth of CC using dual real-time auto feedback system that incorporated an infrared camera (CPR evolution(™)).
  
  
  RESULTS
  On the floor, the true depth of CC was 5.0±0.0cm (n=100), or identical to the depth of CC performed by the machine. The Shinnosukekun(™) measured a mean (±SD) CC depth of 5.0±0.1cm (n=100), and the CPRmeter(™) measured a depth of 5.0±0.2cm (n=100). On the mattress, the true depth of CC was 4.4±0.0cm (n=100). The Shinnosukekun(™) measured a mean CC depth of 4.4±0.0cm (n=100), and the CPRmeter(™) measured a depth of 4.7±0.1cm (n=100). The data of CPRmeter(™) were overestimated (P<.0001 between the true depth and the CPRmeter(™)-measured depth).
  
  
  CONCLUSIONS
  The Shinnosukekun(™) could correctly measure the depth of CC on a mattress. According to our present results, the flexible pressure sensor could be a useful feedback system for CC performed on a soft surface.
authors.affiliation: Emergency Life Saving and Technique Tokyo, Hachioji, Tokyo, Japan. Electronic address: kminami@med.uoeh-u.ac.jp.
authors.forename: Kouichiro
authors.initials: K
authors.lastname: Minami
authors.affiliation: New Products Development Office, New Business Research and Development Laboratories, Research and Development Headquarters, SUMITOMO RIKO Company Limited, Komaki-shi, Aichi, Japan.
authors.forename: Yota
authors.initials: Y
authors.lastname: Kokubo
authors.affiliation: New Products Development Office, New Business Research and Development Laboratories, Research and Development Headquarters, SUMITOMO RIKO Company Limited, Komaki-shi, Aichi, Japan.
authors.forename: Ichinosuke
authors.initials: I
authors.lastname: Maeda
authors.affiliation: New Products Development Office, New Business Research and Development Laboratories, Research and Development Headquarters, SUMITOMO RIKO Company Limited, Komaki-shi, Aichi, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Hibino
mesh_terms: D001513:Beds; D004867:Equipment Design; D006336:Heart Massage / Q000379:methods*; D006801:Humans; D008348:Manikins; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D011312:Pressure