Ultrasonic transmit and receive system

• US 6,122,222 A
• Filed: 05/07/1999
• Issued: 09/19/2000
• Est. Priority Date: 03/02/1995
• Status: Expired due to Term

• Current Assignee: Acuson Corporation (Siemens AG)
• Original Assignee: Acuson Corporation (Siemens AG)
• Inventors: Mo, Jian-Hua, Hossack, John A.
• Primary Examiner(s): Pihulic, Daniel T.
• Application Number:
  US09/307,491
• Time in Patent Office: 501 Days
• Field of Search: 367/138, 367/7, 367/11, 367/103, 367/105, 600/447, 600/458
• US Class Current: 367/7
• CPC Class Codes: G01N 2291/012 Phase angle
• CPC Class Codes: G01N 2291/015 Attenuation, scattering
• CPC Class Codes: G01N 2291/106 one or more transducer arrays
• CPC Class Codes: G01N 29/2456 Focusing probes focusing arrangements G01N29/221
• CPC Class Codes: G01N 29/2462 Probes with waveguides, e.g. SAW devices
• CPC Class Codes: G01N 29/262 by electronic orientation or focusing, e.g. with phased arrays phased arrays per se G10K11/34
• CPC Class Codes: G01N 29/343 pulse waves, e.g. particular sequence of pulses, bursts
• CPC Class Codes: G01N 29/348 with frequency characteristics, e.g. single frequency signals, chirp signals measuring frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04; measuring frequency or analysing frequency spectra G01R23/00
• CPC Class Codes: G01N 29/40 by amplitude filtering, e.g. by applying a threshold or by gain control
• CPC Class Codes: G01N 29/42 by frequency filtering or by tuning to resonant frequency
• CPC Class Codes: G01N 29/46 by spectral analysis, e.g. Fourier analysis or wavelet analysis spectral signal processing per se G06F17/14
• CPC Class Codes: G01S 15/8909 using a static transducer configuration
• CPC Class Codes: G01S 15/895 characterised by the transmitted frequency spectrum
• CPC Class Codes: G01S 7/5202 for pulse systems
• CPC Class Codes: G01S 7/52034 Data rate converters
• CPC Class Codes: G01S 7/52036 using analysis of echo signal for target characterisation
• CPC Class Codes: G01S 7/52038 involving non-linear properties of the propagation medium or of the reflective target
• CPC Class Codes: G01S 7/52039 exploiting the non-linear response of a contrast enhancer, e.g. a contrast agent diagnostic techniques involving the use of contrast agents A61B8/481
• 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 7/52047 for elimination of side lobes or of grating lobes; for increasing resolving power
• CPC Class Codes: G10K 11/341 : Circuits therefor
• CPC Class Codes: G10K 11/343 : using frequency variation or different frequencies

Abstract

A transmit beamformer includes multiple transducers, each responsive to a respective transmit waveform to produce a respective transducer waveform. A transmit waveform generator generates the transmit waveforms, and the transmit waveforms each include multiple frequency components. Progressively higher frequency components of the transmit waveforms are timed to cause corresponding progressively higher frequency components of the transducer waveforms to focus along a line at progressively shorter ranges. In this way, a frequency dependent line focus is achieved.

Claims

1. An ultrasonic imaging system comprising:

a two dimensional transducer array;

a transmit beamformer operatively coupled with the two dimensional transducer array and operative to generate waveforms at fundamental frequencies; and

a receive beamformer operatively coupled with the two dimensional transducer array and having an adjustable filter operative to receive echo signals from the two dimensional transducer array and to filter out echoes at the fundamental frequencies and pass echoes at a harmonic frequency.

2. The ultrasonic imaging system of claim 1 wherein the transmit beamformer is operative to focus a first frequency component at a first depth and a second frequency component at a second depth.

3. The ultrasonic imaging system of claim 1 wherein the adjustable filter comprises a time varying filter.

4. The ultrasonic imaging system of claim 1 wherein the adjustable filter comprises a digital finite impulse response filter.

5. The ultrasonic imaging system of claim 1 wherein the adjustable filter comprises a filter operable to provide adjustable decimation.

6. The ultrasonic imaging system of claim 1 wherein the adjustable filter receives the echo signals and the echo signals are responsive to contrast agents.

7. The ultrasonic imaging system of claim 1 wherein the adjustable filter comprises a bandpass filter.

8. The ultrasonic imaging system of claim 1 wherein the transmit beamformer is operative to generate waveforms comprising a Gaussian spectrum.