DocumentCode :
1422177
Title :
Assessment of Alterations in the Electrical Impedance of Muscle After Experimental Nerve Injury via Finite-Element Analysis
Author :
Wang, Lucy L. ; Ahad, Mohammad ; McEwan, Alistair ; Li, Jia ; Jafarpoor, Mina ; Rutkove, Seward B.
Author_Institution :
Dept. of Neurology, Beth Israel Deaconess Med. Center, Boston, MA, USA
Volume :
58
Issue :
6
fYear :
2011
fDate :
6/1/2011 12:00:00 AM
Firstpage :
1585
Lastpage :
1591
Abstract :
The surface measurement of electrical impedance of muscle, incorporated as the technique of electrical impedance myography (EIM), provides a noninvasive approach for evaluating neuromuscular diseases, including amyotrophic lateral sclerosis. However, the relationship between alterations in surface impedance and the electrical properties of muscle remains uncertain. In order to investigate this further, a group of healthy adult rats, a group of rats two weeks postsciatic crush, and a group of animals six months postcrush underwent EIM of the gastrocnemius-soleus complex. The animals were then killed and the conductivity and permittivity of the extracted muscle measured. Finite-element models based on MRI data were then constructed for each group. The characteristic EIM parameter, 50 kHz phase (±standard error), obtained with surface impedance measurements was 17.3° ± 0.3° for normal animals, 13.8° ± 0.7° for acutely injured animals, and 16.1° ± 0.5° for chronically injured animals. The models predicted parallel changes with phase values of 24.3°, 18.8°, and 21.2° for the normal, acute, and chronic groups, respectively. Other multifrequency impedance parameters showed similar alterations. These results confirm that surface impedance measurements taken in conjunction with anatomical data and finite-element models may offer a noninvasive approach for assessing biophysical alterations in muscle in neuromuscular disease states.
Keywords :
biomedical MRI; biomedical measurement; diseases; electric impedance measurement; electrical conductivity; electromyography; finite element analysis; medical signal processing; neurophysiology; permittivity; physiological models; MRI; amyotrophic lateral sclerosis; conductivity; electrical impedance myography; finite element analysis; frequency 50 kHz; gastrocnemius-soleus complex; multifrequency impedance parameters; muscle; nerve injury; neuromuscular diseases; permittivity; sciatic nerve crush; surface electrical impedance alterations; Animals; Conductivity; Electrodes; Finite element methods; Impedance; Muscles; Surface impedance; Element methods; impedance; muscle; Animals; Electric Impedance; Finite Element Analysis; Linear Models; Magnetic Resonance Imaging; Male; Muscle, Skeletal; Myography; Rats; Rats, Wistar; Sciatic Nerve;
fLanguage :
English
Journal_Title :
Biomedical Engineering, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9294
Type :
jour
DOI :
10.1109/TBME.2011.2104957
Filename :
5682397
Link To Document :
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