A bone monitoring system , comprising: a bone monitoring device adapted to be applied on the skin of a patient adjacent to a target site of a bone, the device comprising: one or more external ultrasound transducers , at least one of the one or more external ultrasound transducers capable of transmitting a wave, and at least one of the one or more external ultrasound transducers capable of receiving the transmitted wave and creating a signal representative of a received wave; and a controller operably coupled with the device and comprising a central processing unit and a memory , wherein the controller is configured to: control at least one of the one or more external ultrasound transducers to transmit at least one ultrasound wave to the target site of the bone; control at least one of the one or more external ultrasound transducers to receive the at least one ultrasound wave to generate sensor readings; store data based on the sensor readings in the memory ; isolate wavelets for a plurality of frequency bands; for each wavelet, extract time-domain data regarding peaks, valleys, and bundle envelopes; and quantify a condition of the bone at the target site from the data based on sensor readings and one or more learning analysis methods; wherein the at least one ultrasound wave comprises a frequency in a range of 0.7 MHz - 3.0 MHz. a bone monitoring device adapted to be applied on the skin of a patient adjacent to a target site of a bone, the device comprising: one or more external ultrasound transducers , at least one of the one or more external ultrasound transducers capable of transmitting a wave, and at least one of the one or more external ultrasound transducers capable of receiving the transmitted wave and creating a signal representative of a received wave; and a controller operably coupled with the device and comprising a central processing unit and a memory , wherein the controller is configured to: control at least one of the one or more external ultrasound transducers to transmit at least one ultrasound wave to the target site of the bone; control at least one of the one or more external ultrasound transducers to receive the at least one ultrasound wave to generate sensor readings; store data based on the sensor readings in the memory ; isolate wavelets for a plurality of frequency bands; for each wavelet, extract time-domain data regarding peaks, valleys, and bundle envelopes; and quantify a condition of the bone at the target site from the data based on sensor readings and one or more learning analysis methods; wherein the at least one ultrasound wave comprises a frequency in a range of 0.7 MHz - 3.0 MHz. control at least one of the one or more external ultrasound transducers to transmit at least one ultrasound wave to the target site of the bone; control at least one of the one or more external ultrasound transducers to receive the at least one ultrasound wave to generate sensor readings; store data based on the sensor readings in the memory ; isolate wavelets for a plurality of frequency bands; for each wavelet, extract time-domain data regarding peaks, valleys, and bundle envelopes; and quantify a condition of the bone at the target site from the data based on sensor readings and one or more learning analysis methods; wherein the at least one ultrasound wave comprises a frequency in a range of 0.7 MHz - 3.0 MHz. <EOS>