Biomechanical response of human rib cage to cardiopulmonary resuscitation maneuvers: Effects of the compression location

Abstract

The biomechanical response of a human rib cage to cardiopulmonary resuscitation maneuvers was investigated by means of finite element simulations. We analyzed the effect of the location where the force was applied on the achieved compression depths and stress levels experienced by the breastbone and ribs. For compression locations on the breastbone, a caudal shift of the application area toward the breastbone tip resulted in a 17% reduction of the force required to achieve a target 5 cm compression depth. We found that the use of compression regions located on the costal cartilages would involve higher risk of rib fractures.

The effect of thoracic dimensions on compression depth during cardiopulmonary resuscitation

“…In the present study, we assume a CS value of 1.5 for the costal cartilages, which leads to E c = 27 MPa according to Forman's formula. Suazo et al 15 showed that using this E c value, together with a Poisson ratio of η c = 0.45 for the cartilage, the linear elastic model reproduced fairly well the experimental test results of Forman and Kent 22 …”

“…In the present study, the parameters used in the elastoplastic model for the bone tissue are E b = 7 GPa, η b = 0.45, σ Y = 30 MPa and E T = 2 GPa. Suazo et al 15 showed that these parameter values produced good simulations of the rib bending experiments previously reported by Kindig et al 29 …”

“…The computational mesh resulting from the discretization of the refined geometry model consisted of 1,006,571 nodes and 5,624,647 linear elements (1,235,972 triangles and 4,388,675 tetrahedrals). The compression force is applied into a small patch (some 10 cm 2 in area) on the outer surface of the breastbone (the region referred to as P1 in 15 1C).…”

“…Following Suazo et al, 15 in the present study the costo‐vertebral joints are modeled as capsule‐like volumes of a softer material appended to the rear tip of the ribs. The capsule material was assumed to behave as an elastic solid, with a Young modulus of E j = 1 MPa and a Poisson ratio of η j = 0.45.…”

“…Finite element (FE) simulations provide, at a relatively low cost, the ability to simulate different conditions and to predict the effect of changes in the model parameters. Recently, Suazo et al 15 used a FE approach to simulate the effect of changes in the CPR compression location on the response experienced by an adult rib cage. The aim of the present study is to perform FE simulations of rib cage compression on a set of differently sized adult models and, on the basis of the numerical results obtained, to develop predictive models for the achieved compression depth and rib stress during CPR maneuvers.…”