ObjectiveTo analyze and evaluate the diaphragm motor function in normal healthy people on the basis of M-mode ultrasound, and explore the application value of tissue Doppler in observing the diaphragm motor function.

MethodsA total of 43 healthy volunteers were selected, including 22 males and 21 females, with an average age of (37.5±4.3) years.The M-mode ultrasound was used to obtain the motion amplitude of right diaphragm under calm breathing and deep breathing, and duration and intensity of diaphragm contraction.The range of motion, duration of contraction and intensity of diaphragm under calm breathing and deep breathing were measured by tissue Doppler at the same point of the diaphragm.The tissue Doppler was used to obtain the displacement-time curves of diaphragm at different points during the same respiratory cycle.The parameters obtained by the two methods in calm breathing and deep breathing were compared between two groups.The correlations between the diaphragm motion amplitude and systolic strength measured by the two methods, and lung function were analyzed.The displacement-time curves of the diaphragm at different points in the same respiratory movement period were observed to analyze the synchronicity of the movement.

ResultsIn calm breathing and deep breathing, there was no statistical significance in the amplitude of diaphragm movement between the obtained by quantitative tissue Doppler analysis and that measured by M-mode ultrasound(P>0.05).The differences of the duration and intensity of diaphragm contraction between the two methods in calm breathing and deep breathing were not statistically significant(P>0.05).In the state of deep breathing, there was a strong positive correlation between diaphragm motion amplitude and systolic strength, and lung function obtained by two methods(P < 0.01).The diaphragmatic movement of normal people in the same respiratory movement cycle has synchronization.

ConclusionsThe quantitative analysis of tissue Doppler ultrasound can quantitatively evaluate the contractive motion of diaphragm, the movement of diaphragm muscle in the same respiratory cycle of normal people is synchronized, and which lays a foundation for the tissue Doppler ultrasound to evaluate diaphragm motion in pathological state.