Ultrasonic diagnostic apparatus
AssigneeTokyo Shibaura Denki Kabushiki Kaisha
InventorYuuichi Muranaka
Life of this patent
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Abstract
In an ultrasonic diagnostic apparatus, the center frequency of the spectrum of the received echo signal is decreased, depending upon the penetration depth of the patient. This phenomenon is noticeable when the frequency of the excited ultrasonic waves is selected to a higher range. The ultrasonic diagnostic apparatus employs an STC circuit, a gain of which is varied in accordance with the penetration depth of the patient.
Claims13
An ultrasonic diagnostic apparatus for displaying a tomographic image of an object to be investigated, the apparatus comprising:
- a transducer means, including an array of ultrasonic vibration elements, for applying beams of ultrasonic waves into the object at preselected steering angles, receiving ultrasonic echo signals reflected from the object, and converting the received echo signals into electric echo signals;
- transmitter means coupled with said transducer means for applying timed electric pulses to the array of ultrasonic vibration elements in a manner that produces beams of ultrasonic waves deflected at preselected steering angles;
- a variable gain amplification means coupled with said transducer means for receiving electric echo signals from said transducer means and selectively amplifying the received electric echo signals;
- signal means for producing signals representative of the steering angle of each respective ultrasonic beam;
- a gain sensitivity control means responsive to the deflection angle of the respective ultrasonic beams and coupled with said signal means and said variable gain amplification means for increasing the gain of the variable gain amplification means as the steering angle of the respective ultrasonic beams increases;
- and
- display means coupled with said variable gain amplification means for converting the amplified echo signals into a tomographic image of the object being investigated.
An ultrasonic diagnostic apparatus for displaying a tomographic image of an object to be investigated, the apparatus comprising:
- a transducer means, including an array of ultrasonic vibration elements, for applying beams of ultrasonic waves into the object at preselected steering angles, receiving ultrasonic echo signals reflected from the object and converting the received signals into electric echo signals;
- transmitter means coupled with said transducer means for applying timed electric pulses to the array of ultrasonic vibration elements in a manner that produces beams of ultrasonic waves deflected at preselected steering angles;
- variable band pass filter means for receiving electric echo signals from said transducer means and selectively filtering the received electric echo signals;
- signal means for producing signals representative of the steering angle of each respective ultrasonic beam;
- a frequency sensitivity control means responsive to the deflection angle of the respective ultrasonic beams and coupled with said signal means and said variable band pass filter means for decreasing the band pass of the variable band pass filter as the steering angle of the respective ultrasonic beams increases;
- and
- display means coupled with said variable gain amplification means for converting the filtered echo signals into a tomographic image of the object being investigated.
Dependencies are inferred from the claim text.