Ultrasonic diagnosis system

• US 4,566,459 A
• Filed: 02/14/1984
• Issued: 01/28/1986
• Est. Priority Date: 02/14/1983
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ogawa, Toshio, Umemura, Shinichiro, Katakura, Kageyoshi
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): Jaworski, Francis J.
• Application Number:
  US06/580,166
• Time in Patent Office: 714 Days
• Field of Search: 128/660-661, 73/597, 73/598, 73/602, 73/626
• US Class Current: 600/443
• CPC Class Codes: A61B 8/00 Diagnosis using ultrasonic, sonic or infrasonic waves imaging of objects using sonar G01S15/00
• CPC Class Codes: G01S 15/8918 the array being linear
• CPC Class Codes: G01S 15/8927 using simultaneously or sequentially two or more subarrays or subapertures
• CPC Class Codes: G01S 7/52046 Techniques for image enhancement involving transmitter or receiver image enhancement by image data processing G06T5/00
• CPC Class Codes: G01S 7/52065 Compound scan display, e.g. panoramic imaging
• CPC Class Codes: G10K 11/345 using energy switching from one active element to another

Abstract

An ultrasonic diagnosis system comprising a variable setting arrangement including an ultrasonic transducer array for transmitting a pulse-like ultrasonic wave to an object and detecting a reflection wave from the object, and assuming the acoustic velocity of the object; a control arrangement for determining the depth of electronic focusing in accordance with this assumed acoustic velocity; and a display for displaying the assumed acoustic velocity. The ultrasonic diagnosis system determines whether the reflection signal of the object at a predetermined position is in-focus or out-of-focus and knows the actual acoustic velocity of the object from the assumed acoustic velocity when the reflection signal is in-focus.

Claims

1. An ultrasonic diagnosis system comprising:

a transducer array having a plurality of transducer elements;

transmitting means for driving said transducer elements so that a pulse-like ultrasonic wave is transmitted from said transducer array to an object;

receiving means for receiving reflection signals from said transducer elements, the reflection signals being indicative of reception at said transducer elements of waves reflected from said object;

signal generating means for generating an adjustable signal representative of an assumed acoustic velocity for said object;

indicating means for indicating the assumed velcoity of said object;

focusing means for delaying respective reflection signals in accordance with a delay amount distribution and for summing the delayed reflection signals, the delay amount distribution being determined in accordance with the assumed acoustic velocity so that a receiving ultrasonic beam of said transducer elements is focused to a predetermined focal point; and

display means for displaying an image of said object by converting an output of said focusing means to a visual signal;

whereby an actual acoustic velocity of said object is indicated by said indicating means when said adjustable signal of said signal generating means is adjusted so that an image of a reflector on said image of said object displayed by said display means has the highest intensity.

2. An ultrasonic diagnosis system according to claim 1, further comprising selecting means for selecting one number of transducer elements of said transducer array in response to said tansmitting means and another number of transducer elements of said transducer array in response to said receiving means, a greater number of transducer elements of said transducer array being selected in response to said receiving means than the number of transducer elements of said transducer array in response to said transmitting means so that the receiving aperture of said transducer array is larger than the transmitting aperture of said transducer array.

3. An ultrasonic diagnosis system according to claim 2, wherein said selecting means is responsive to said receiving means for selecting three groups of transducer elements of said transducer array, the three groups of transducer elements being located at the center and both ends of said transducer array.

4. An ultrasonic diagnosis system according to claim 1 further comprising selecting means for selecting transducer elements of said transducer array, said selecting means being responsive to said receiving means for selecting three groups of transducer elements of said transducer array, said three groups of transducer elements being located at the center and both ends of said transducer array.

5. An ultrasonic diagnosis system according to claim 1, wherein said focusing means provides for scanning said predetermined focal point along a line of a depth direction for achieving real time dynamic focusing.

6. An ultrasonic diagnosis system comprising:

a transducer array having a plurality of transducer elements;

transmitting means for repeatedly driving said transducer elements so that pulse-like ultrasonic waves are repeatedly transmitted from said transducer array to an object;

receiving means for receiving reflection signals representative of perception at said transducer elements of said transducer array of reflection waves from reflectors in said object;

delay means for delaying respective reflection signals in accordance with a changeable delay distribution;

summing means for summing the delayed reflection signals;

self-running control means for providing a gradually changing control signal for controlling said changeable delay amount distribution to said delay means;

automatic focus detection means for stopping the gradual change of the gradually changing control signal when a peak value of the output of said summing means becomes a maximum value; and

calculating means for calculating the acoustic velocity of said object in accordance with an initial value and the stopped value of the gradually changing control signal.

7. A method for measuring acoustic velocity of an object comprising the steps of:

transmitting a pulse-like ultrasonic wave from a transducer array having a plurality of transducer elements to the object by applying driving signals to the transducer elements;

receiving from the transducer elements reflection signals indicative of reception at the transducer elements of reflecting waves from reflectors in the object by summing the reflection signals from the transducer elements;

delaying at least one of respective driving signals applied to the transducer elements and respective reflection signals from the transducer elements in accordance with a predetermined delay amount distribution so that at least one of the pulse-like ultrasonic wave and a receiving ultrasonic beam are focused to a point at a predetermined distance;

determining the delay amount distribution in accordance with the predetermined distance and an assumed acoustic velocity;

measuring the time elapsed for the pulse-like ultrasonic wave to be transmitted and a reflection signal of the highest intensity to return to the transducer array; and

determining an actual acoustic velocity of the object in accordance with the predetermined distance, the assumed acoustic velocity and the elapsed time.

8. A method for measuring acoustic velocity of an object comprising the steps of:

transmitting a pulse-like ultrasonic wave from a transducer array having a plurality of transducer elements to the object by applying driving signals to the transducer elements;

receiving from the transducer elements reflection signals indicative of reception at the transducer elements of reflecting waves from reflectors in the object by summing the reflection signals from the transducer elements

delaying at least one of respective driving signals applied to the transducer elements and respective reflection signals from the transducer elements in accordance with a predetermined delay amount distribution so that at least one of the pulse-like ultrasonic wave and a receiving ultrasonic beam are focused to a point at a predetermined distance;

determining the delay amount distribution in accordance with the predetermined distance and an assumed acoustic velocity;

displaying an image of the reflection signals; and

determining the acoustic velocity of the object by adjusting the assumed acoustic velocity and repeating the steps of transmitting, receiving and displaying so as to obtain an image of a reflector having the highest intensity, the acoustic velocity of the object corresponding to the assumed acoustic velocity utilized for obtaining the image having the highest intensity.

9. Amethod for measuring acoustic velocity of an object comprising the steps of:

transmitting a pulse-like ultrasonic wave from a transducer array having a plurality of transducer elements to the object by applying driving signals to the transducer elements;

receiving from the transducer elements reflection signals indicative of reception at the transducer elements of reflecting waves from reflectors in the object by summing the reflection signals from the transducer elements;

delaying respective reflection signals from the transducer elements in accordance with a time varying delay amount distribution so that a focus point of a receiving ultrasonic beam is scanned along a line of depth direction;

determining the time varying delay amount distribution in accordance with an assumed acoustic veleocity;

displaying an image of a reflection signal; and

determining the acoustic velocity of the object by adjusting the assumed acoustic velocity and repeating the steps of transmitting, receiving and displaying so as to obtain an image having the highest intensity, the acoustic velocity of the object corresponding to the assumed acoustic velocity for obtaining the image having the highest intensity.