Abstract: An apparatus and a method are provided for directing an ultrasonic signal along a desired path through a member and for establishing the strength of the member. A transmitter sends an ultrasonic signal through the member that is received by a receiver and a conditioned electronic waveform is generated that is representative of the received waveform. Selected characteristics of the conditioned electronic waveform are compared with corresponding characteristics of a canonical waveform, the canonical waveform being obtained when ultrasonic signals propagate along the desired path through the member. When the selected characteristics of the conditioned electronic waveform are substantially the same as the corresponding characteristics of the canonical waveform, the ultrasonic signal has propagated at least along the desired path. The apparent velocity of the ultrasonic signal that propagates along the desired path is computed and is related to bone strength.