Noninvasive vibration measurement system and method for measuring amplitude of vibration of tissue in an object being investigated

• US 4,819,649 A
• Filed: 11/03/1986
• Issued: 04/11/1989
• Est. Priority Date: 11/03/1986
• Status: Expired due to Term

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Rogers, Peter H., Cox, Helen M.
• Primary Examiner(s): Jaworski, Francis
• Assistant Examiner(s): MANUEL, GEORGE C
• Application Number:
  US06/926,452
• Time in Patent Office: 890 Days
• Field of Search: 128/328, 128/660, 128/24 A, 128/660.02, 73/599, 73/602, 73/624, 73/625, 73/626, 73/627, 73/628, 73/629, 73/632, 73/633
• US Class Current: 600/438
• CPC Class Codes: A61B 5/12 Audiometering
• CPC Class Codes: A61B 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: G01N 29/11 by measuring attenuation of acoustic waves
• CPC Class Codes: G01S 15/50 Systems of measurement, based on relative movement of the target

Abstract

A system and method for measuring the acoustically induced vibrations within a living organism. The object is ensonified to set it into low frequency vibration. A continuous wave beam of ultrasonic energy is transmitted along one path and focused at the tissue to be investigated. A focused transducer receives the reflected beam along a second axis such that the intersection of the transmitted and received beams define a small, concentrated region positioned at the object under investigation. The received beam is phase modulated by the amplitude of vibration of the object producing sidebands whose amplitude can be ratioed to the amplitude of the high frequency peak to determine the absolute amplitude of the low frequency vibration.

Claims

1. The method of investigating an acoustically vibrating object which comprises the steps of obtaining an acoustically vibrating object, transmitting a focused beam of ultrasonic continuous wave energy along one axis into the object, receiving a focused beam of reflected ultrasonic energy along a second axis from the object, intersecting the axes of the transmitted and received beams such that the beams at the intersection of their axes define a small, concentrated spot within the object, relatively positioning the object under investigation and the concentrated spot so that the received beam is phase modulated by the vibration of the object, the modulated received beam including a carrier and sidebands and determining the amplitude of vibration of the object from the phase modulation of the received beam.

2. The method as defined in claim 1 wherein the step of determining the amplitude of vibration of the object includes comparing the amplitudes of sidebands resulting from phase modulation to the amplitude of the carrier in the received beam.

3. The method of investigating a vibrating entity with ultrasonic energy which comprises the steps of focusing continuous wave ultrasonic energy on the entity, receiving continuous wave ultrasonic energy reflected or scattered by the entity, and determining the amplitude of vibration of the object from the phase modulation of the received energy as phase modulated by the vibration of the object.

4. Apparatus for investigating a particular volume within a living organism which comprises the combination of:

means for non-invasively illuminating the particular volume within the living organism with continuous wave ultrasonic energy;

means for vibrating the living organism including the particular volume being investigated at a frequency which causes vibration of the particular volume being investigated to phase modulate the continuous wave ultrasonic energy returned from the particular volume being investigated;

means for determining the amplitude of vibration of the particular volume being investigated from the phase modulated continuous wave untrasonic energy.

5. Apparatus as defined in claim 4 wherein said means for determining the amplitude of vibration includes means for comparing the amplitude of upper and lower sidebands to the amplitude of the continuous wave ultrasonic energy.

6. The method of investigating the amplitude response of living tissue of a living organism to an excitation frequency which causes acoustic vibration of the living tissue being investigated, which comprises the steps of:

subjecting the living organism to the excitation frequency;

focusing continuous wave ultrasonic energy on the living tissue being investigated so that the living tissue being investigated reflects or scatters ultrasonic energy which is phase modulated by vibrational movement of the living tissue being investigated;

determining the amplitude of the vibration of the living tissue being investigated from the reflected or scattered continuous wave ultrasonic energy.

7. The method of investigating tissue of a living organism which comprises the steps of:

vibrating the living organism at an excitation frequency which causes vibration of the tissue being investigated;

focusing low power ultrasonic energy on the tissue being investigated by coupling such ultrasonic energy to the living organism through a liquid medium, the frequency of the ultrasonic energy being a continuous wave form so that the continuous wave ultrasonic energy reflected or scattered from the tissue being investigated is phase modulated by the vibration of the tissue being investigated to produce upper and lower sidebands generally centered on the frequency of the ultrasonic energy;

detecting, through the liquid medium, the phase modulated energy reflected or scattered from the tissue being investigated; and

determining the amplitude of vibration of the living tissue being investigated from the ratio of the amplitude of the upper and lower sidebands to the amplitude of the continuous wave frequency of the detected ultrasonic energy.

8. Apparatus for investigating the amplitude response of living tissue of a living organism to an excitation frequency which causes vibration of the living tissue being investigated, which comprises the combination of:

means for subjecting the living organism to an excitation frequency which causes vibration of the living tissue being investigated;

means for focusing continuous wave ultrasonic energy on the living tissue being investigated so that the living tissue being investigated reflects or scatters ultrasonic energy phase modulated by vibrational movement of the living tissue being investigated; and

means for determining the amplitude of the vibration of the living tissue being investigated from the reflected or scattered ultrasonic energy.

9. The method of investigating a particular region of living tissue of a living organism, which comprises the steps of:

ensonifying the living organism with low frequency acoustic energy having a spectrum including a frequency which causes the particular region to vibrate;

focusing continuous wave ultrasonic energy on the particular region of the living tissue in which the focused continuous wave energy is of a frequency sufficiently high so that vibration of the particular region of the living tissue is substantially unaffected thereby;

detecting the continuous wave ultrasonic energy on the particular region of the living tissue in which the focused continuous wave energy is of a frequency sufficiently high so that vibration of the particular region of the living tissue is substantially unaffected thereby;

detecting the continuous wave ultrasonic energy reflected or scattered by the particular region as phase modulated by the vibrational movement of the particular region of the living tissue; and

determining the amplitude of vibration of the particular region of the living tissue from the detected continuous wave ultrasonic energy as phase modulated by the vibrational movement of the living tissue.