Apparatus and method for a noninvasive estimate of the characteristics of a periodic/cyclic bodily sound in a region close to its source

Apparatus for noninvasively determining a source sound pressure of a source located inside of a body, the source transmitting a generally periodic acoustic signal including at least one signal component to a surface of the body, the system comprising:

• a first acoustic transducer disposed on the surface for receiving the signal component at the surface of the body;
• a second acoustic transducer disposed on the surface of the body;
• and
• a source pressure determination system comprising:
• a signal generator configured to generate an estimated phase-inverted signal component responsive to the signal component received at the surface by the first acoustic transducer, the phase-inverted signal component approximating a phase-inverted version of the received signal component, and
• a controller for:
• a) providing a predetermined time increment to the signal generator for advancing the generated phase-inverted signal component, the predetermined time increment corresponding to a distance of the signal component within the body, the second acoustic transducer transmitting the advanced phase-inverted signal component provided by the signal generator toward the source, and
• b) adjusting at least one feature of the estimated phase-inverted signal generated by the signal generator until a further signal received from the first acoustic transducer approximates a minimum value, the controller setting the adjusted signal component as the phase-inverted signal component corresponding to the signal component at the distance,
• wherein the source pressure determination system determines the phase-inverted signal component that corresponds to the signal component being proximate to the source.