Dual-mode ultrasonic assessment of bone

A system for non-invasive and quantitative assessment of the status of bone tissue in a bony member within a living organism, comprising:

• a first transducer configured for coupling to skin disposed over the bony member;
• a second transducer configured for coupling to skin disposed over the bony member;
• a controller coupled to the first and second transducers and configured to:
• generate a first control signal causing the first transducer to
• generate a first axial ultrasound signal from the first transducer towards and into the bony member wherein portions of the first axial ultrasound signal travel along a longitudinal axis of the bony member in a first axial direction;
• receive first and second portions of the first axial ultrasound signal at a first pair of acoustic elements of the first transducer after the first and second portions of the first axial ultrasound signal have exited the bony member and generate a first pair of axial output signals in response;
• process the first pair of axial output signals to obtain an axial transmission time delay;
• generate a second control signal causing the second transducer to
• generate a first radial ultrasound signal from the second transducer towards and into the bony member wherein portions of the first radial ultrasound signal are reflected by the bony member in a direction away from the longitudinal axis of the bony member;
• receive first and second portions of the first radial ultrasound signal after reflection by the bony member and generate a pulse-echo output signal in response;
• process the pulse-echo output signal to obtain a pulse-echo time delay corresponding to a transit time for the first radial ultrasound signal to travel between a periosteum of the bony member and an endosteum of the bony member;
• and,
• generate an estimate of a characteristic of the bone tissue responsive to the axial-transmission time delay and the pulse-echo time delay.

A method of non-invasive and qualitative assessment of the status of bone tissue in a bony member within a living organism, comprising the steps of:

• acoustically coupling a transducer to skin disposed over the bony member;
• generating a first axial ultrasound signal from the transducer towards and into the bony member wherein portions of the first axial ultrasound signal travel along a longitudinal axis of the bony member in a first axial direction;
• receiving first and second portions of the first axial ultrasound signal at a first pair of acoustic elements of the transducer after the first and second portions of the first axial ultrasound signal have exited the bony member and generating a first pair of axial output signals in response;
• processing the first pair of axial output signals to obtain an axial transmission time delay;
• generating a first radial ultrasound signal from the transducer towards and into the bony member wherein portions of the first radial ultrasound signal are reflected by the bony member in a direction away from the longitudinal axis of the bony member;
• receiving first and second portions of the first radial ultrasound signal after reflection by the bony member and generating a pulse-echo output signal in response;
• processing the pulse-echo output signal to obtain a pulse-echo time delay corresponding to a transit time for the first radial ultrasound signal to travel between a periosteum of the bony member and an endosteum of the bony member;
• and,
• generating an estimate of a characteristic of the bone tissue responsive to the axial-transmission time delay and the pulse-echo time delay.

A method of non-invasive and qualitative assessment of the status of bone tissue in a bony member within a living organism, comprising the steps of:

• acoustically coupling a first transducer to skin disposed over the bony member;
• generating a first axial ultrasound signal from the first transducer towards and into the bony member wherein portions of the first axial ultrasound signal travel along a longitudinal axis of the bony member in a first axial direction;
• receiving first and second portions of the first axial ultrasound signal at a first pair of acoustic elements of the first transducer after the first and second portions of the first axial ultrasound signal have exited the bony member and generating a first pair of axial output signals in response;
• processing the first pair of axial output signals to obtain an axial transmission time delay;
• acoustically coupling a second transducer to skin disposed over the bony member;
• generating a first radial ultrasound signal from the second transducer towards and into the bony member wherein portions of the first radial ultrasound signal are reflected by the bony member in a direction away from the longitudinal axis of the bony member;
• receiving first and second portions of the first radial ultrasound signal after reflection by the bony member and generating a pulse-echo output signal in response;
• processing the pulse-echo output signal to obtain a pulse-echo time delay corresponding to a transit time for the first radial ultrasound signal to travel between a periosteum of the bony member and an endosteum of the bony member;
• and,
• generating an estimate of a characteristic of the bone tissue responsive to the axial-transmission time delay and the pulse-echo time delay.

A method of non-invasive and quantitative assessment of the status of bone tissue in a bony member within a living organism, comprising the steps of:

• acoustically coupling a transducer to skin disposed over the bony member;
• generating a first axial-ultrasound signal in the bony member along a longitudinal axis of the bony member in a first axial direction to obtain a first pair of axial-ultrasound output signals, and generating a second axial-ultrasound signal in the bony member along the longitudinal axis of the bony member in a second axial direction, wherein the second axial direction is opposite to the first axial direction, to obtain a second pair of axial-ultrasound output signals;
• processing the first pair of axial-ultrasound output signals and the second pair of axial-ultrasound output signals, to obtain an axial-transmission time delay;
• generating a radial ultrasound signal and directing the radial ultrasound signal from the transducer radially through the bone tissue to obtain a pulse-echo output signal;
• processing the pulse-echo output signal to obtain a pulse-echo time delay corresponding to a transit time for the radial ultrasound signal to travel between a periosteum of the bony member and an endosteum of the bony member;
• and,
• generating an estimate of a characteristic of the bone tissue responsive to both the axial-transmission time delay and the pulse-echo time delay.