US 6,485,420 B1 · Attenuation leveling method and apparatus for improved ultrasonic wave propagation

Abstract

Improved ultrasonic wave propagation in connection with operation of ultrasonic imaging systems is made possible by the method of attenuation leveling. Attenuation leveling allows effective focusing of systems that operate through irregular surfaces that cause uneven attenuation effects. Apparatus is provided to implement this method in clinical applications and research applications. The basic attenuation leveling is accomplished with material that attenuates like the body part to be imaged. The apparatus includes conformal surfaces that are in contact with a patient's body that serve to prevent direct contact of the body with the attenuating material. It also includes fairing surfaces that modify shape of a patient's body to enable scanning of surfaces. Alternate devices include stand-off devices and immersion configurations.

Claims51

Dependent claims

A sensing system for examining a subject, said sensing system comprising

(a) a transducer device that operates in relation to propagating wavefronts, and
(b) said propagating wavefronts propagate in a medium that causes signal attenuation that variably attenuates signals that are distributed over said wavefronts, and
(c) attenuation leveling material placed in the path of said propagating wavefronts that compensates for variable attenuation to control signal amplitude for said signals that are distributed over a wavefront, and
(d) a fairing device placed in the path of said propagating wavefronts that reduces uneven surfaces of said subject of examination, and
(e) a conforming surface placed in the path of said propagating wavefronts that prevents direct contact of a surface of said subject of examination and said attenuation leveling material.

2 more elements

An ultrasonic system comprising

(a) a transducer that operates in relation to waves in a subject material, where said waves are related to said transducer through a medium by propagation through said medium, where said propagation is described by wavefronts that travel between said transducer and points in said subject material, where signals that are distributed over a wavefront have relative magnitude that conforms to an amplitude distribution function, where effectiveness of system operations depends on propagation where such signal distributions do not deviate from desired amplitude distribution functions, and
(c) a conforming arrangement of different materials that implements said medium to enable said propagation, where said different materials include a coupling material where said coupling material intervenes between said transducer and said subject material, and where said conforming arrangement causes path length variations in said subject material such that, for a said coupling material that does not attenuate, said path length variations would cause deviation from a desired amplitude distribution function, and
(d) said coupling material having an attenuation effect such that said coupling material is an attenuation leveling material, where said leveling attenuation effect matches an attenuation effect of said subject material so as to provide approximately uniform attenuation in said medium such that significant deviation from said desired amplitude distribution functions is prevented.

Dependencies are inferred from the claim text.

Attenuation leveling method and apparatus for improved ultrasonic wave propagation

Life of this patent

Attenuation leveling method and apparatus for improved ultrasonic wave propagation

Life of this patent

Abstract

Claims51