Acoustical imaging system

Claim 2

In a method for generating frequency demodulated acoustic images of a body organ, said method including the steps of generating an electrical signal at a defined frequency, projecting said signal against said organ, receiving the acoustic pressure signals reflected from said organ, frequency demodulating said reflected signals to produce the scattering properties of said organ, and displaying images of said demodulated signal, the improvement comprising: generating a fixed frequency signal; and adding said fixed frequency signal to said reflected acoustic pressure signals prior to said frequency demodulation such that low-level signals or noise in said reflected acoustic pressure signals is suppressed, whereby said images are enhanced.

Claim 3

The method as defined in claim 1, wherein said step of generating said fixed frequency signal comprises: generating a sine wave signal having a frequency of approximately 2 MHz.

Claim 4

The method as defined in claim 2, wherein said step of generating said fixed frequency signal further comprises: generating said sine wave with an amplitude in the range of 0 to -20 db below the amplitude of said reflected acoustic pressure signal.

Claim 7

The method as defined in claim 2, wherein said step of generating said squelch signal comprises: generating a sine wave signal having a frequency of approximately 2 MHz.

Claim 8

The method as defined in claim 5, wherein said step of generating said squelch signal further comprises: generating said sine wave with an amplitude in the range of 0 to -20 db below the amplitude of said reflected acoustic pressure signal.

Claim 9

An improved system for generating an electrical signal having instantaneous frequency deviations corresponding to the scattering properties of a media supporting acoustic pulse propagation against which said signal is electrically projected, said system having a transmitter for generating a first electrical signal, a transducer for transforming said signal into said acoustic pulse and projecting said pulse into said media, a receiver to transform echo pulse returns into a second electrical signal, and a frequency demodulator for processing said second electrical signal, said improvement comprising: squelch means, coupled to the output of said receiver, for suppressing low level signals at the input of said frequency demodulator, whereby low level noise effects on said second electrical signal are substantially eliminated.

Claim 10

An improved system for generating an electrical signal having instantaneous frequency deviations corresponding to the scattering properties of a media supporting acoustic pulse propagation against which said signal is electrically projected, said system having a transmitter for generating a first electrical signal, a transducer for transforming said signal into said acoustic pulse and projecting said pulse into said media, a receiver to transform echo pulse returns into a second electrical signal, and a frequency demodulator for processing said second electrical signal, said improvement comprising: squelch means, coupled to the output of said receiver, for suppressing low level signals at the input of said frequency demodulator, whereby low level noise effects on said second electrical signal are substantially eliminated.

Claim 11

The improvement as defined in claim 7, wherein said squelch means comprises: signal generator means for variably generating a fixed frequency wave; and circuit means, coupling said signal generator means to said output of said receiver, for adding said fixed frequency wave to said secondary signal.

Claim 12

The improvement as defined in claim 8, wherein said fixed frequency wave comprises: a sine wave having a frequency of approximately 2 MHz.

Claim 13

The improvement as defined in claim 9, wherein said sine wave has an amplitude in the range of 0 to -20 db below the amplitude of said first signal.

Claim 14

An improvement to a system for displaying frequency demodulated acoustic images of an object, said system being of the type having: a transmitter for generating a signal at a defined frequency; a transducer for transforming said electrical signal into an ultrasonic acoustic pressure signal, for projecting said acoustic pressure signal against said object, and for receiving acoustic pressure signals reflected from said object in response to said projected acoustic pressure signal; a receiver for transforming said reflected acoustic pressure signal into an electrical signal; a frequency demodulator for frequency demodulating said electrical signal of said receiver to produce a frequency demodulated signal containing instantaneous frequency deviations from said defined frequency responsive to the scattering properties of said object; and means for transforming said frequency demodulated signal into a video signal and for displaying said video signal, said improvement comprising: signal generator means, for generating a fixed frequency sine wave squelch signal; and circuit means for adding electrical signals, coupling said signal generator means to the output of said receiver such that said squelch signal captures said frequency demodulated signal, whereby said acoustic images are enhanced.

Claim 15

An improvement to a system for displaying frequency demodulated acoustic images of an object, said system being of the type having: a transmitter for generating a signal at a defined frequency; a transducer for transforming said electrical signal into an ultrasonic acoustic pressure signal, for projecting said acoustic pressure signal against said object, and for receiving acoustic pressure signals reflected from said object in response to said projected acoustic pressure signal; a receiver for transforming said reflected acoustic pressure signal into an electrical signal; a frequency demodulator for frequency demodulating said electrical signal of said receiver to produce a frequency demodulated signal containing instantaneous frequency deviations from said defined frequency responsive to the scattering properties of said object; and means for transforming said frequency demodulated signal into a video signal and for displaying said video signal, said improvement comprising: signal generator means, for generating a fixed frequency sine wave squelch signal; and circuit means for adding electrical signals, coupling said signal generator means to the output of said receiver such that said squelch signal captures said frequency demodulated signal, whereby said acoustic images are enhanced.