Anterior-Posterior Thoracic Force-Deflection Characteristics Measured During Cardiopulmonary Resuscitation: Comparison to Post-Mortem Human Subject Data

In comparative thoracic compression response data using both post mortem human subjects (PMHS) and live subjects, live subject tests often include muscle tensing effects and are at low deflections. Several of these limitations have been overcome through novel technology development. A clinical monitor-defibrillator has had a load cell and accelerometer integrated into it to measure applied force and chest compression during live human cardio-pulmonary resuscitation (CPR). The sensor is interposed between the patient's sternum and the CPR administrator's hands. Comparison of thoracic force-deflection measured during adult PMHS hub-based loading and adult CPR is the study objective. CPR creates a unique setting similar to a frontal crash environment for chest mechanics during thoracic loading using maximum chest deflection and minimal muscle tensing. Progressive spring in parallel with a viscous damper were used in PMHS and CPR data modeling. Model parameter statistical comparison describing thoracic compliance during large compressions showed that during testing under specific loading conditions less force at equivalent deflections were generated by chest compressions during CPR than the PMHS. Specifically, 40 mm deflection for CPR data was 286 N and for PMHS was 588 N. This may be partially explained through load application area and engaged thoracic structural differences. Also, the suggestion that the thorax's viscoelastic nature is more pronounced with naturally perfused tissues before substantial tissue autolysis has begun is gained through response difference when during CPR greater hysteresis was shown than during PMHS. The authors present adult thorax mechanical response fundamental biomechanical data that increases understanding of potential differences between PMHS and chest response obtained during CPR and prior to onset of substantial tissue autolysis. Important future force-deflection estimates may continue by measuring thoracic compliance during CPR.

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  • Authors:
    • Arbogast, Kristy B
    • Maltese, Matthew R
    • Nadkarni, Vinay M
    • Steen, Petter Andreas
    • Nysaether, Jon B
  • Conference:
  • Publication Date: 2006-11


  • English

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  • Accession Number: 01046246
  • Record Type: Publication
  • ISBN: 139780768018295
  • Files: TRIS
  • Created Date: Apr 10 2007 4:21PM