Ultrasonic pulse temperature determination method and apparatus

• US 4,754,760 A
• Filed: 03/30/1987
• Issued: 07/05/1988
• Est. Priority Date: 11/13/1986
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Square Enix
• Original Assignee: Agency of Industrial Science & Technology, Ministry of International Trade & Industry (Government of Malaysia)
• Inventors: Ueno, Shinichirou, Fukukita, Hiroshi
• Primary Examiner(s): Jaworski, Francis J.
• Application Number:
  US07/031,372
• Time in Patent Office: 463 Days
• Field of Search: 728/660-663, 73/597, 73/599-600, 73/602, 374/117-119
• US Class Current: 600/438
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 8/5223 for extracting a diagnostic or physiological parameter from medical diagnostic data for algorithms to analyse biomedical images G06T7/0012
• CPC Class Codes: G01H 5/00 Measuring propagation velocity of ultrasonic, sonic or infrasonic waves , e.g. of pressure waves
• CPC Class Codes: G01S 7/52036 using analysis of echo signal for target characterisation
• CPC Class Codes: G01S 7/527 Extracting wanted echo signals Doppler systems G01S15/50
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

A first ultrasonic pulse formed by the superposition of a probe pulse on a pump pulse having a frequency lower than the center frequency of the ultrasonic probe pulse where the particle velocity of the pump pulse is in the vicinity of zero in addition to which the particle acceleration of which is at a constant portion, and a second pulse formed by the superposition of the probe pulse center frequency on the peak particle velocity portion of the pump pulse, as well as a probe pulse alone, are transmitted into a specimen before and after it is heated and the reflections of the transmitted signals from two or more reflecting points that are at different depths in the specimen are received. The received signals are subjected to frequency analysis and the spectral shift and the phase shift of the probe pulse and superposed pulses are obtained, and from these values the attenuation of the probe pulse between the differing depths is determined. Such an attenuation determination is obtained before and after heating of the specimen and the change in temperature of the specimen is determined from the obtained attenuation values on the basis of a pre-prepared table of changes in attenuation factor in accordance with changes in the temperature of the specimen.

Claims

1. A method for determining temperature of a specimen which utilizes ultrasonic pulses, comprising the steps of:

providing an ultrasonic probe pulse having a center frequency, forming a first pulse by superposing the probe pulse on a pump pulse having a a frequency lower than the center frequency of the ultrasonic probe pulse where a particle velocity of the pump pulse is in the vicinity of zero in addition to which a particle acceleration of which is at a constant portion,

forming a second pulse by superposing the probe pulse center frequency on a peak particle velocity portion of the pump pulse,

transmitting said first and second and probe pulses into the specimen, receiving the reflections of the transmitted signals from two or more reflecting points that are at different depths in the specimen,

heating said specimen, repeating said transmitting and receiving steps,

subjecting the received signals to frequency analysis and obtaining a spectral shift and a phase shift of the probe pulse and the superposed pulses, and from these values obtaining the attenuation of the probe pulse between differing depths in the specimen before and after heating, and estimating the change in temperature of the specimen from the obtained attenuation values on the basis of a pre-prepared table of changes in attenuation factor in accordance with changes in the temperature of the specimen.

2. The method according to claim 1, wherein said specimen is a living organism.

3. The method according to claim 1 wherein said heating step is a heat treatment of cancer in said specimen.

4. An ultrasonic apparatus for determining the temperature within a region, comprising:

(a) transudcer means for emitting ultrasonic probe pulses and pump pulses into said region,

(b) phase control driving means for controlling said transducer means to emit a first pulse comprising a probe pulse having a center frequency superimposed on a pump pulse having a frequency lower than the center frequency of the ultrasonic probe pulse at a first superposition location on said pump pulse, and to emit a second pulse comprising a probe pulse superimpsed on a said pump pulse at a second different location on said pump pulse, and to emit a probe pulse into said region,

(c) means for receiving said first and second and probe pulse and for detecting the amount of phase shift of the received first and second pulses with respect to said probe pulse,

(d) means responsive to said receiving means for determining the temperature change within said region from the detected amounts of spectral and phase shifts of said received pulses.

5. An apparatus according to claim 4, wherein said phase control driving means and receiving means include means for controlling the emission and receiving of pulses at successive times, and said temperature determining means determines change in temperature between said successive times.

6. An apparatus according to claim 4 wherein said specimen is a living organism and said temperature change is the temperature change within said region during cancer diathermy treatment,

7. An apparatus according to claim 4 wherein said temperature change determining means comprises means for determining the attenuation within said region from said detected spectral and phase shift amounts and providing an output thereof, and means for determining the temperature change within said region responsive to said attenuation output.

8. An ultrasonic apparatus for determining the attenuation of a region of a specimen, comprising:

(a) transducer means for emitting ultrasonic probe pulses and pump pulses into said region,

(b) phase control driving means for controlling said transducer means to emit a first pulse comprising a probe pulse having a center frequency superimposed on a pump pulse having a frequeny lower than the center frequency of the ultrasonic probe pulse at a first superposition location on said pump pulse, and to emit a second pulse comprising a probe pulse superimposed on a said pump pulse at a second different location on said pump pulse, and to emit a probe pulse into said region,

(c) means for receiving said first and second and probe pulses and for providing an output indicative of the spectral content thereof,

(d) means responsive to said receiving means and spectral content output thereof for determining the amounts of phase shift and spectral shift of the spectral content outputs associated with said first and second pulses with respsect to the spectral content output associated with said probe pulse, and for providing outputs indicative thereof,

(e) means for determining the attenuation of said specimen region responsive to said outputs of said phase shift and spectral shift determining means.