TY - JOUR
T1 - Electrically induced mechanomyograms reflect inspiratory muscle strength in young or elderly subjects
AU - Watanabe, Shogo
AU - Nojima, Ippei
AU - Agarie, Yuuna
AU - Watanabe, Tatsunori
AU - Fukuhara, Shinichi
AU - Fujinaga, Takeshi
AU - Oka, Hisao
N1 - Funding Information:
This work was supported by a JSPS Grant-in-Aid for Young Scientists (B) Grant Number 23700628 .
Publisher Copyright:
© 2016 The Japanese Respiratory Society
PY - 2016/11/1
Y1 - 2016/11/1
N2 - Background Respiratory muscle strength has been used as a tool for evaluating respiratory rehabilitation in chronic obstructive pulmonary disease. However, mouth pressure measurement evaluated by maximum expiratory mouth pressure (PEmax) or inspiratory mouth pressure (PImax) offers an indirect method for measuring respiratory muscle strength. We demonstrated the evaluation of diaphragm contractility using a mechanomyogram (MMG), which is the mechanical signal generated by the motion of the diaphragm induced by the electric stimulation of the phrenic nerve. Methods Study participants were 21 young and 20 elderly subjects with no symptoms of respiratory disease. The elderly subjects were divided into non-smoker or smoker groups. The smoker group was defined as subjects having a Brinkman Index of greater than 300. We measured basic spirometric parameters, mouth pressure (PEmax, PImax), and diaphragmatic MMG. Results Diaphragmatic MMG showed more clear contrast between young subjects and elderly non-smoker or smoker subjects than the conventional method for respiratory muscle contraction (PEmax, PImax). In addition, the diaphragmatic MMG strongly correlated with inspiratory muscle strength. Conclusions Diaphragmatic MMG may reflect diaphragmatic contractility more directly and sensitively than the conventional method.
AB - Background Respiratory muscle strength has been used as a tool for evaluating respiratory rehabilitation in chronic obstructive pulmonary disease. However, mouth pressure measurement evaluated by maximum expiratory mouth pressure (PEmax) or inspiratory mouth pressure (PImax) offers an indirect method for measuring respiratory muscle strength. We demonstrated the evaluation of diaphragm contractility using a mechanomyogram (MMG), which is the mechanical signal generated by the motion of the diaphragm induced by the electric stimulation of the phrenic nerve. Methods Study participants were 21 young and 20 elderly subjects with no symptoms of respiratory disease. The elderly subjects were divided into non-smoker or smoker groups. The smoker group was defined as subjects having a Brinkman Index of greater than 300. We measured basic spirometric parameters, mouth pressure (PEmax, PImax), and diaphragmatic MMG. Results Diaphragmatic MMG showed more clear contrast between young subjects and elderly non-smoker or smoker subjects than the conventional method for respiratory muscle contraction (PEmax, PImax). In addition, the diaphragmatic MMG strongly correlated with inspiratory muscle strength. Conclusions Diaphragmatic MMG may reflect diaphragmatic contractility more directly and sensitively than the conventional method.
KW - Electric stimulation
KW - Mechanomyogram
KW - Respiratory muscle strength
KW - Smoking
UR - http://www.scopus.com/inward/record.url?scp=84979632760&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84979632760&partnerID=8YFLogxK
U2 - 10.1016/j.resinv.2016.06.001
DO - 10.1016/j.resinv.2016.06.001
M3 - Article
C2 - 27886855
AN - SCOPUS:84979632760
VL - 54
SP - 436
EP - 444
JO - Respiratory Investigation
JF - Respiratory Investigation
SN - 2212-5345
IS - 6
ER -