Ultrasonic diagnostic apparatus with multiple focal lengths

• US 4,850,363 A
• Filed: 10/13/1988
• Issued: 07/25/1989
• Est. Priority Date: 10/16/1986
• Status: Expired due to Term

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Yanagawa, Yutaka
• Primary Examiner(s): Jaworski, Francis
• Assistant Examiner(s): MANUEL, GEORGE C
• Application Number:
  US07/258,061
• Time in Patent Office: 285 Days
• Field of Search: 128/660.09, 128/660.1, 128/662.06, 128/660.01
• US Class Current: 600/445
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/14 Echo-tomography
• CPC Class Codes: A61B 8/445 Details of catheter construction
• CPC Class Codes: A61B 8/4461 Features of the scanning mechanism, e.g. for moving the transducer within the housing of the probe

Abstract

First and second ultrasonic transducers having the same resonance frequency are provided at the distal end portion of an endoscope. Ultrasonic lenses having different focal lengths are mounted on first and second transducers, respectively. First and second transducers are rotated around the axis of the insertion portion and mechanically radial-scan an object to be examined. A controller supplies timing signals for driving the transducers in response to the radial-scan to a diagnostic device. The diagnostic device supplies drive pulses synchronized with the timing signals to either of first and second transducers. Ultrasonic echo signals received by first and second transducers are converted into reception signals and input to the diagnostic device. The diagnostic device synthesizes only those signals among the reception signals falling within predetermined distance ranges including focal points to form a tomographic image of the object.

Claims

1. An ultrasonic diagnostic apparatus comprising:

a plurality of transducers having the same resonance frequency and different respective focal lengths;

scanning means for scanning said plurality of transducers such that said transducers radiate ultrasonic waves in the same plane;

driving means for applying drive signals having the same frequency to said plurality of transducers;

said plurality of transducers receiving echo signals corresponding to reflected radiated ultrasonic waves, and producing corresponding reception signals; and

synthesizing means for receiving reception signals from said plurality of transducers and for synthesizing only those reception signals from said plurality of transducers which represent distances falling within a predetermined distance range including the focal length of the respective transducer, to thereby form an image viewed in said same plane;

said synthesizing means comprising;

time gain controlling means for performing complemental time gain control of said reception signals from said plurality of transducers, said time gain controlling means including means for increasing gain during a time period corresponding to the focal length of each transducer, after the transducers have radiated ultrasonic waves; and

modulating means for modulating the output signal from said time gain controlling means to control a brightness of an image viewed in said same plane.

2. An apparatus according to claim 1, in which said scanning means scans said plurality of transducers in a given direction such that said driving means sequentially drives all of said plurality of transducers in said given direction.

3. An apparatus according to claim 1, in which said scanning means scans said plurality of transducers in a given direction such that said driving means sequentially drives at least one of said plurality of transducers in said given direction.

4. An ultrasonic diagnostic apparatus for an endoscope, comprising:

a plurality of transducers provided at a distal end of an insertion portion of an endoscope and having the same resonance frequency and different respective focal lengths, said insertion portion having an axis;

scanning means for integrally rotating said plurality of transducers in a plane perpendicular to said axis of said insertion portion of said endoscope such that said transducers radiate ultrasonic waves in the same plane;

driving means for sequentially applying drive signals having the same frequency to said plurality of transducers;

said plurality of transducers receiving echo signals corresponding to reflected radiated ultrasonic waves, and producing corresponding reception signals; and

synthesizing means for receiving reception signals from said plurality of transducers and for synthesizing only reception signals from said plurality of transducers which represent distances falling within a predetermined distance range including the focal length of the respective transducer, to thereby form an image viewed in said same plane;

said synthesizing means comprising;

time gain controlling means for performing complemental time gain control of said reception signals from said plurality of transducers and for producing output signals, said time gain controlling means including means for increasing gain during a time period corresponding to the focal length of each transducer, after the transducers have radiated ultrasonic waves; and

modulating means for modulating the output signals from said time gain controlling means to control a brightness of an image viewed in said same plane.

5. An apparatus according to claim 4, in which said scanning means scans said plurality of transducers in a given direction such that said driving means sequentially drives all of said plurality of transducers in said given direction.

6. An apparatus according to claim 4, in which said scanning means scans said plurality of transducers in a plurality of directions, such that said driving means sequentially drives said plurality of transducers in all of said directions and drives only one of said plurality of transducers in one of said directions.

7. An apparatus according to claim 4, in which:

the endoscope of said ultrasonic diagnostic apparatus comprises grip means;

said plurality of transducers each have transducer surfaces and respective opposite surfaces, and wherein said transducers are adhered with each other so as to be integral with each other on said surface opposite to their said transducer surfaces; and

said grip means comprises said scanning means mounted thereto, said scanning means comprising a motor having a rotatable shaft coupled thereto, said rotatable shaft extending along said axis of said insertion portion, and a transmission member coupled to said rotatable shaft for transmitting a rotational force of rotatable shaft of said motor to said plurality of transducers which are adhered with each other.