Methods and apparatus for the examination and treatment of internal organs

• US 5,993,393 A
• Filed: 01/12/1995
• Issued: 11/30/1999
• Est. Priority Date: 07/14/1992
• Status: Expired due to Term

• Current Assignee: Jomed Imaging Ltd. (JOMED NV)
• Original Assignee: Jomed Imaging Ltd. (JOMED NV)
• Inventors: Barlow, Christopher John, Ryan, Patrick Joseph, Dickinson, Robert Julian
• Primary Examiner(s): Jaworski, Francis J.
• Application Number:
  US08/367,276
• Time in Patent Office: 1,783 Days
• Field of Search: 128/660.01, 128/660.07, 128/661.01, 128/662.03, 128/662.06, 73/625-626, 600/437, 600/443, 600/447, 600/459, 600/462-463
• US Class Current: 600/463
• CPC Class Codes: G01S 15/8927 using simultaneously or sequentially two or more subarrays or subapertures
• CPC Class Codes: G01S 15/8997 using synthetic aperture techniques
• CPC Class Codes: G01S 7/52028 using digital techniques
• CPC Class Codes: G01S 7/52034 Data rate converters

Abstract

Ultrasonic apparatus for visualizing the internal organs of the human body using an ultrasonic array probe is characterized by means for digitising the ultrasonic echo signals and means for processing the digitised signals. Data may be sampled from each array element excited separately, or on a group of elements sequentially with a very small time increment between samples. Processing of data can include switching the transmit carrier frequency between scans, compensation for ringing effects in the transducers, synthetic aperture focussing techniques, software envelope or transform demodulation, attenuation or time gain correction and data compression.

Claims

1. Ultrasonic apparatus for visualizing internal organs of a human body, comprising:

means for energizing elements of an ultrasonic transducer array to transmit ultrasonic vibrations from the elements;

means for acquiring echo signals in response to said energization;

means for sampling the echo signals at sample intervals so as to digitize said echo signals;

means for applying a delay to each echo signal;

means for storing a program;

means for controlling said means for applying a delay in accordance with said stored program so as to enable the delays to be produced by interpolation so they can take any value within a sample interval and to be less than the sample intervals; and

said means for applying a delay operates independently of the means for sampling.

2. Apparatus as claimed in claim 1 in which a sampling frequency of the means for sampling is in the range of twice to four times the signal frequency.

3. Ultrasonic apparatus for visualizing internal organs of a human body, comprising:

means for energizing elements of an ultrasonic transducer array to transmit ultrasonic vibrations from the elements;

means for acquiring echo signals in response to said energization;

means for sampling the echo signals at a sampling rate so as to digitize said echo signals;

means for applying a delay to each sampled echo signal; and

means for generating a data block in response to the sampled and delayed echo signals, in which the data block is always of a preset size irrespective of a field of view of the transducer array, said means for generating a data block being adapted to use the sampling rate according to the field of view in order to keep the amount of data to be processed constant and being adapted to increase the number of excitation cycles as the field of view increases, so that ultrasound resolution relates to displayed resolution.

4. Ultrasonic apparatus for visualizing internal organs of a human body, comprising:

means for energizing elements of an ultrasonic transducer array to transmit ultrasonic vibrations from the elements;

means for acquiring echo signals in response to said energization;

means for sampling the echo signals so as to digitize said echo signals;

means for applying a delay to each echo signal; and

means for generating a data block in response to the sampled and delayed echo signals, in which the data block is always of a preset size irrespective of a field of view of the transducer array, said means for generating a data block being adapted to increase the number of excitation cycles as the field of view increases, so that ultrasound resolution relates to displayed resolution.

5. Ultrasonic apparatus for visualizing internal organs of a human body, comprising:

means for energizing elements of an ultrasonic transducer array to transmit ultrasonic vibrations from the elements;

means for acquiring echo signals in response to said energization;

means for sampling the echo signals so as to digitize said echo signals;

means for applying a delay to each echo signal;

means for generating a data block in response to the sampled and delayed echo signals, in which the data block is always of a preset size irrespective of a field of view of the transducer array, said means for generating a data block being adapted to increase the number of excitation cycles as the field of view increases, so that ultrasound resolution relates to displayed resolution; and

means for tailoring the number of cycles in a transmit pulse to the field of view.

6. Ultrasonic apparatus for visualizing internal organs of a human body, comprising:

means for energizing elements of an ultrasonic transducer array to transmit ultrasonic vibrations from the elements;

means for acquiring echo signals in response to said energization;

means for sampling the echo signals so as to digitize said echo signals;

means for applying a delay to each echo signal;

means for exciting transducers of said transducer array at two frequencies, one frequency being a non-resonant frequency in order to reduce ring-down; and

means for combining echo signals acquired at the two frequencies to allow display of echoes normally in a ringdown region of the transducer.

7. Ultrasonic apparatus for visualizing internal organs of a human body, comprising:

means for exciting a sub-group of at least one transducer element of an ultrasonic transducer array to transmit ultrasonic vibrations from the at least one element;

means for acquiring echo signals by said at least one transducer element in response to said excitation;

means for employing a synthetic aperture focusing with respect to said echo signals; and

means for sampling the echo signals received by both a given transducer element of said sub-group and at least one other transducer element of a sub-group which is different from the excited sub-group, both of which echo signals were acquired in response to the excitation of said at least one transducer element of said sub-group, so as to digitize said echo signals.

8. Ultrasonic apparatus for visualizing internal organs of a human body, comprising:

means for exciting a sub-group of at least one transducer element of an ultrasonic transducer array to transmit ultrasonic vibrations from the at least one element, wherein said means for exciting excites a single transducer element of a sub-group at a time,

means for acquiring echo signals by said at least one transducer element in response to said excitation;

wherein said means for acquiring acquires said echo signals from said single transducer element, and

means for sampling the echo signals received by both a given transducer element of said sub-group and at least one other transducer element of a sub-group which is different from the excited sub-group, both of which echo signals were acquired in response to the excitation of said at least one transducer element of said sub-group, so as to digitize said echo signals, wherein said means for sampling samples the echo signals received by only said single transducer element and thereafter only on another transducer element of a sub-group which is different from the single transducer element of the excited sub-group.

9. Apparatus as claimed in claim 8 wherein said means for exciting transmits on said single transducer element and said means for acquiring thereafter acquires echo signals from only said single transducer element during a first acquisition step, and then in a second sequential acquisition step, said means for exciting for acquiring thereafter acquires echo signal from only said another transducer element of the different sub-group.

10. Ultrasonic apparatus for visualizing internal organs of a human body, comprising:

means for exciting a sub-group of at least one transducer element of an ultrasonic transducer array to transmit ultrasonic vibrations from at least one element;

means for acquiring echo signals by at least one transducer element in response to said excitations;

means for sampling the echo signals received by both a given transducer element of said sub-group and at least one other transducer element of a sub-group which is different from the excited sub-group, both of which echo signals were acquired in response to the excitation of said at least one transducer element of said sub-group, so as to digitize said echo signals;

means for applying a delay to each echo signal;

means for storing a program;

means for controlling said means for applying a delay in accordance with said stored program so as to enable the delays to be produced by interpolation and to be less than the sample intervals; and

said means for applying a delay operates independently of the means for sampling.

11. Ultrasonic apparatus for visualizing internal organs of a human body, comprising the steps of:

exciting a sub-group of at least one transducer element of an ultrasonic transducer array to transmit ultrasonic vibrations from at least one element;

acquiring echo signals by at least one transducer element in response to said excitations;

sampling the echo signals received by both a given transducer element of said sub-group and at least one other transducer element of a sub-group which is different from the excited sub-group, both of which echo signals were acquired in response to the excitation of said at least one transducer element of said sub-group, so as to digitize said echo signals;

applying a delay to each echo signal, independently of the sampling;

storing a program;

controlling said delay in accordance with said stored program so as to enable the delays to be produced by interpolation and to be less than the sample intervals.

12. Ultrasonic apparatus for visualizing internal organs of a human body, comprising:

a catheter for insertion within a blood vessel of a person;

an ultrasonic transducer array formed at an end of the catheter and including at least one transducer element;

means for exciting a sub-group of at least one transducer element of an ultrasonic transducer array to transmit ultrasonic vibrations from the at least one element;

means for acquiring echo signals by said at least one transducer element in response to said excitation; and

means for sampling the echo signals received by both a given transducer element of said sub-group and at least one other transducer element of a sub-group which is different from the excited sub-group, both of which echo signals were acquired in response to the excitation of said at least one transducer element of said sub-group, so as to digitize said echo signals, and a sampling frequency of the means for sampling is in the range of twice to four times the signal frequency.

13. Ultrasonic apparatus for visualizing internal organs of a human body, comprising:

a catheter for insertion within a blood vessel of a person;

an ultrasonic transducer array formed at an end of the catheter and including at least one transducer element;

means for energizing elements of the ultrasonic transducer array to transmit ultrasonic vibrations from the elements;

means for acquiring echo signals in response to said energization;

means for sampling the echo signals at a sampling rate so as to digitize said echo signals;

means for applying a delay to each sampled echo signal; and

means for generating a data block in response to the sampled and delayed echo signals, in which the data block is always of a preset size irrespective of a field of view of the transducer array, said means for generating a data block being adapted to use the sampling rate according to the field of view in order to keep the amount of data to be processed constant and being adapted to increase the number of excitation cycles as the field of view increases, so that ultrasound resolution relates to displayed resolution.

14. Ultrasonic apparatus for visualizing internal organs of a human body, comprising:

a catheter for insertion within a blood vessel of a person;

an ultrasonic transducer array formed at an end of the catheter and including at least one transducer element;

means for energizing elements of the ultrasonic transducer array to transmit ultrasonic vibrations from the elements;

means for acquiring echo signals in response to said energization;

means for sampling the echo signals so as to digitize said echo signals;

means for applying a delay to each sampled echo signal; and

means for generating a data block in response to the sampled and delayed echo signals, in which the data block is always of a preset size irrespective of a field of view of the transducer array, said means for generating a data block being adapted to increase the number of excitation cycles as the field of view increases, so that ultrasound resolution relates to displayed resolution.

15. Ultrasonic apparatus for visualizing internal organs of a human body, comprising:

a catheter for insertion within a blood vessel of a person;

an ultrasonic transducer array formed at an end of the catheter and including at least one transducer element;

means for energizing elements of the ultrasonic transducer array to transmit ultrasonic vibrations from the elements;

means for acquiring echo signals in response to said energization;

means for sampling the echo signals so as to digitize said echo signals;

means for applying a delay to each sampled echo signal;

means for generating a data block in response to the sampled and delayed echo signals, in which the data block is always of a preset size irrespective of a field of view of the transducer array, said means for generating a data block being adapted to increase the number of excitation cycles as the field of view increases, so that ultrasound resolution relates to displayed resolution; and

means for tailoring the number of cycles in a transmit pulse to the field of view.

16. Ultrasonic apparatus for visualizing internal organs of a human body, comprising:

a catheter for insertion within a blood vessel of a person;

an ultrasonic transducer array formed at an end of the catheter and including at least one transducer element;

means for energizing elements of the ultrasonic transducer array to transmit ultrasonic vibrations from the elements;

means for acquiring echo signals in response to said energization;

means for sampling the echo signals so as to digitize said echo signals;

means for applying a delay to each sampled echo signal;

means for exciting transducers of said transducer array at two frequencies, one frequency being a non-resonant frequency in order to reduce ring-down; and

means for combining echo signals acquired at the two frequencies to allow display of echoes normally in a ringdown region of the transducer.

17. Ultrasonic apparatus for visualizing internal organs of a human body, comprising:

a catheter for insertion within a blood vessel of a person;

an ultrasonic transducer array formed at an end of the catheter and including at least one transducer element;

means for exciting a sub-group of at least one transducer element of the ultrasonic transducer array to transmit ultrasonic vibrations from the at least one element;

means for acquiring echo signals by said at least one transducer element in response to said excitation;

means for employing a synthetic aperture focusing with respect to said echo signals; and

means for sampling the echo signals received by both a given transducer element and at least one other transducer element of a sub-group which is different from the excited sub-group, so as to digitize said echo signals.

18. Apparatus as claimed in claim 17 wherein:

said means for exciting excites a single transducer element of a sub-group at a time,

said means for acquiring acquires said echo signals from said single transducer element, and

said means for sampling samples the echo signals received by only said single transducer element and thereafter only on another transducer element of a sub-group which is different from the single transducer element of the excited sub-group.

19. Ultrasonic apparatus for visualizing internal organs of a human body, comprising:

a catheter for insertion within a blood vessel of a person;

an ultrasonic transducer array formed at an end of the catheter and including at least one transducer element;

means for exciting a sub-group of at least one transducer element of an ultrasonic transducer array to transmit ultrasonic vibrations from the at least one element, wherein said means for exciting excites a single transducer element of a sub-group at a time;

means for acquiring echo signals by said at least one transducer element in response to said excitation, wherein said means for acquiring acquires said echo signals from said single transducer element; and

means for sampling the echo signals received by both a given transducer element and at least one other transducer element of a sub-group which is different from the excited sub-group, so as to digitize said echo signals, wherein said means for sampling samples the echo signals received by only said single transducer element and thereafter only on another transducer element of a sub-group which is different from the single transducer element of the excited sub-group; and

wherein said means for exciting transmits on said single transducer element and said means for acquiring thereafter acquires echo signals from only said single transducer element during a first acquisition step, and then in a second sequential acquisition step, said means for exciting transmits on said single transducer element, and said means for acquiring thereafter acquires echo signal from only said another transducer element of the different sub-group.

20. Ultrasonic apparatus for visualizing internal organs of a human body, comprising:

a catheter for insertion within a blood vessel of a person;

an ultrasonic transducer array formed at an end of the catheter and including at least one transducer element;

means for exciting a sub-group of at least one transducer element of the ultrasonic transducer array to transmit ultrasonic vibrations from at least one element;

means for acquiring echo signals by at least one transducer element in response to said excitations;

means for sampling the echo signals received by both a given transducer element of said sub-group and at least one other transducer element of a sub-group which is different from the excited sub-group, both of which echo signals were acquired in response to the excitation of said at least one transducer element of said sub-group, so as to digitize said echo signals;

means for applying a delay to each echo signal;

means for storing a program;

means for controlling said means for applying a delay in accordance with said stored program so as to enable the delays to be produced by interpolation and to be less than the sample intervals; and

said means for applying a delay operates independently of the means for sampling.

21. Ultrasonic method for visualizing internal organs of a human body, comprising the steps of:

a catheter for insertion within a blood vessel of a person;

an ultrasonic transducer array formed at an end of the catheter and including at least one transducer element;

exciting a sub-group of at least one transducer element of the ultrasonic transducer array to transmit ultrasonic vibrations from at least one element;

acquiring echo signals by at least one transducer element in response to said excitations;

sampling the echo signals received by both a given transducer element of said sub-group and at least one other transducer element of a sub-group which is different from the excited sub-group, both of which echo signals were acquired in response to the excitation of said at least one transducer element of said sub-group, so as to digitize said echo signals;

applying a delay to each echo signal, independently of the sampling;

storing a program;

controlling said delay in accordance with said stored program so as to enable the delays to be produced by interpolation and to be less than the sample intervals.