A snapshot of the RF excitation pulse that was used to energize the transmitting transducer.
A pulse received by the receiving transducer after propagation through a 9 mm block of polystyrene.
A plot of the received pulse after application of the synthetic impulse method.
One of the 17 different cortical bone phantoms from two sets, which varied in BMD from 0 to 1700 mg/cm3.
The NCU measurement configuration showing the upper and lower transducers, the monitor screen, the scanning system, and the computer software utilized to measure the SOS, IR, attenuation, and thickness for all of the cortical bone phantoms.
The velocity/thickness algorithm uses measurements of the time of flight and signal strength in these four propagation paths. P1 and P4 are the two transmission paths and P2 and P3 represent the two reflection paths.
Measurements of SOS as a function of density comparing the data collected from conventional contact ultrasound by using the single transducer pulse-echo technique with data collected from the authors’ sia-7 and NCA-1000 noncontact analysis programs with their NCU analyzer. Both programs were used to collect data from the BN and NEW phantom sets during the dates noted in the legend, on the right.
(a) IR as a function of phantom density using the NCA-1000 and Pathway 4 (P4) which is used for pulses that are emitted from the upper transducer, transmitted through the sample, and received by the lower transducer. (b) IR as a function of phantom density measured using the sia-7 protocol for the same pathway as in (a).
Transmittance images of the cortical bone phantoms using the IPass system. The BMD ranges from 150 to 1250 mg/cm3.
Average transmittance of the IPass C-scans as a function of phantom density for both phantom sets. A least-squares line fit is included and plotted.
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