TY - GEN
T1 - Measuring neck nerve strain
T2 - 2nd Frontiers in Biomedical Devices Conference 2007
AU - Johnson, Tara L.
AU - LaPointe, Vanessa
AU - Shoukas, Artin A.
AU - Gurewitsch, Edith D.
AU - Allen, Robert H.
PY - 2007/11/23
Y1 - 2007/11/23
N2 - We sought to determine the effects of head rotation, lateral neck flexion, and traction force on brachial plexus (BP) nerve strain, specifically at C5-C6 (Erb's point), and C7, C8, and T1 roots in a multi-"filament" 3D model of the fetal BP. Using our constructed simulator and a tailored data acquisition system, strain readings were recorded and accurate to within <2%. Using our model and a position-sensing system, controlled loads and deformations were applied to a fetal head attached to a flexible spine. For each simulation, we measured BP strain at Erb's point, and C7, C8, and T1 roots. Increasing total traction force increases strain in the upper and middle nerves (Erb's point, C7, and C8). Lateral neck flexion produces the most strain (up to 25.4±6.6% in Erb's point with 4.5 kg (10 lbs) of traction), with concomitant head rotation magnifying strain levels by up to a factor of 1.7. Increasing head rotation and lateral neck flexion increases the strain in the lower nerve roots more than in the upper roots, in general, upper nerves undergo double the strain of lower nerves. Direct axial traction has the least effect, with 4.5 kg of traction producing a peak strain of 3.6±2.5% at Erb's point. BP strain can be reduced at Erb's point, C7, and C8 by maintaining neutral alignment between the head and trunk prior to applying traction, which should be minimized.
AB - We sought to determine the effects of head rotation, lateral neck flexion, and traction force on brachial plexus (BP) nerve strain, specifically at C5-C6 (Erb's point), and C7, C8, and T1 roots in a multi-"filament" 3D model of the fetal BP. Using our constructed simulator and a tailored data acquisition system, strain readings were recorded and accurate to within <2%. Using our model and a position-sensing system, controlled loads and deformations were applied to a fetal head attached to a flexible spine. For each simulation, we measured BP strain at Erb's point, and C7, C8, and T1 roots. Increasing total traction force increases strain in the upper and middle nerves (Erb's point, C7, and C8). Lateral neck flexion produces the most strain (up to 25.4±6.6% in Erb's point with 4.5 kg (10 lbs) of traction), with concomitant head rotation magnifying strain levels by up to a factor of 1.7. Increasing head rotation and lateral neck flexion increases the strain in the lower nerve roots more than in the upper roots, in general, upper nerves undergo double the strain of lower nerves. Direct axial traction has the least effect, with 4.5 kg of traction producing a peak strain of 3.6±2.5% at Erb's point. BP strain can be reduced at Erb's point, C7, and C8 by maintaining neutral alignment between the head and trunk prior to applying traction, which should be minimized.
KW - Brachial plexus
KW - Mechanical model
KW - Nerve strain
UR - http://www.scopus.com/inward/record.url?scp=36248936534&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=36248936534&partnerID=8YFLogxK
U2 - 10.1115/BioMed2007-38073
DO - 10.1115/BioMed2007-38073
M3 - Conference contribution
AN - SCOPUS:36248936534
SN - 0791842665
SN - 9780791842669
T3 - Proceedings of the 2nd Frontiers in Biomedical Devices Conference 2007
SP - 15
EP - 16
BT - Proceedings of the 2nd Frontiers in Biomedical Devices Conference 2007
Y2 - 7 June 2007 through 8 June 2007
ER -