The invention discloses a multi-mode ultrasonic
coupling analysis
system for measuring
bone mineral density. The
system comprises a shell, a foot placing groove, a sole supporting plate, a display screen, a first
transducer, a second
transducer, a clamping mechanism and a
signal collecting and
processing module, wherein the first
transducer and the second transducer are oppositely arranged. A detachable double-state
coupling piece is installed at the front end of the transducer, the
coupling piece is provided with a first coupling face and a second coupling face which are equal in thickness but different in
acoustic impedance, and the first coupling face and the second coupling face make contact with the
skin in sequence when used. The device carries out
bidirectional transmission measurement under multiple frequencies, the
processing module averagely extracts transmission
frequency dispersion characteristics through two-state difference and reciprocity, the
center frequency, sharpness and sensitivity of a transmission window are obtained through fitting, and cortical-spongy transmission window indexes are formed and used for distinguishing
osteoporosis phenotypes and longitudinal follow-up visit. According to the method, a traditional homogeneous model that QUS only depends on sound velocity and attenuation is broken through,
frequency dispersion window characteristics of a cortical-cancellous double-layer structure are introduced into clinical quantitative indexes for the first time, and sensitivity to early
osteoporosis and follow-up visit reliability are improved.