Tunable ultrasound transmitter

Patent metadata

Field	Value
Publication number	US-2016101436-A1
Application number	US-201514887267-A
Country	US
Kind code	A1
Filing date	Oct 19, 2015
Priority date	Jan 13, 2010
Publication date	Apr 14, 2016
Grant date	—

Abstract

The use of power-efficient transmitters to establish acoustic wave energy having low undesirable harmonics is achieved by adjusting the transmitter output waveform to minimize the undesirable harmonics. In one embodiment both the timing and slope of the waveform edges are adjusted to produce the desired output waveform having little or no second harmonics. In the embodiment, output waveform timing adjustments on the order of fractions of the system clock interval are provided. This then allows for very fine control of a coarsely produced waveform. In one embodiment, the user can select the fine tuning to match the transmitter output signal to a particular load transducer.

First claim

1 . A transmitter circuit for delivering acoustical energy to a transducer element; said circuit comprising:
a switching amplifier operable to produce at least a portion of a transmitter output waveform for delivery to said transducer element; and a controller coupled to said amplifier and operable to control at least a portion of the transmitter output waveform to mitigate second-order harmonics from being generated by said transducer element.

2 . The circuit of claim 1 , wherein the switching amplifier comprises a class C switching amplifier.

3 . The circuit of claim 1 wherein said portion of the transmitter output waveform comprises a slope of a voltage transition of the transmitter output waveform.

4 . The circuit of claim 3 wherein the switching amplifier comprises:
an adjustable transistor circuit, wherein said slope of the voltage transition of the transmitter output waveform is controlled by said controller providing control signals to adjust said adjustable transistor circuit.

5 . The circuit of claim 3 further comprising:
a return to zero circuit operable to produce at least a portion of said transmitter output waveform, wherein said return to zero circuit comprises an adjustable transistor circuit, and wherein said slope of the voltage transition of the transmitter output waveform is controlled by said controller providing control signals to adjust said adjustable transistor circuit.

8 . The circuit of claim 1 wherein said controller comprises;
timing control circuitry operable to provide sub-clock cycle adjustment with respect to timing pulses used by said control circuitry in controlling said switching amplifier to produce said at least a portion of the transmitter output waveform.

7 . The circuit of claim 6 wherein said portion of the transmitter output waveform comprises timing of a corner of the transmitter output waveform, wherein the timing of the transmitter output waveform corner is controlled by said timing control circuitry.

8 . A method of performing tissue harmonic imaging, said method comprising:
generating, using a switching amplifier, a transmitter output waveform signal having at least a positive slope portion and a negative slope portion; and for a cycle of said transmitter output waveform signal, allowing said positive slope portion to form unadjusted and modifying said negative slope portion to control formation of said negative slope so that said negative slope conforms to a shape of said positive slope portion.

9 . The method of claim 8 wherein the switching amplifier comprises a class C switching amplifier.

10 . The method of claim 8 further comprising:
delivering said transmit signal to an element of a multi-element transducer.

11 . The method of claim 10 wherein said modifying comprises:
selectively adjusting a pull-down strength of transmitter circuitry utilized in generating said transmitter output waveform signal.

12 . The method of claim 11 , wherein the transmitter circuitry comprises pull-down circuitry of said switching amplifier.

13 . The method of claim 11 , wherein the transmitter circuitry comprises pull-down circuitry of a return to zero circuit utilized to generate said transmitter output waveform signal.

14 . An ultrasound imaging system comprising:
a class C amplifier operable to produce at least a portion of a transmitter output waveform for delivery to an ultrasound transducer element; and a controller coupled to said amplifier and operable to control at least a portion of the transmitter output waveform to mitigate second-order harmonics from being generated by said ultrasound transducer element.

15 . The system of claim 14 wherein the controller comprises: timing control circuitry operable to provide the control of the at least a portion of the transmitter output waveform.

16 . The system of claim 15 wherein said controller comprises:
at least one state machine operable for controlling said timing control circuitry.

17 . The system of claim 15 wherein the portion of the transmitter output waveform comprises timing of a corner of the transmitter output waveform.

18 . The system of claim 15 wherein the timing control circuitry is operable to provide sub-clock cycle adjustment with respect to timing pulses to produce the at least a portion of the transmitter output waveform.

19 . The system of claim 14 wherein the portion of the transmitter output waveform comprises a slope of a voltage transition of the transmitter output waveform.

20 . The system of claim 19 further comprising:
means for controlling a slope of at least one slope portion of said created signals.

21 - 23 . (canceled)

Assignees

• Fujifilm Sonosite Inc

Inventors

• Stice John R
• Wang Yanwei
• Siedenburg Clinton T
• Lundberg Andrew K
• Coughlin Justin
• Nielsen Max

Classifications

• G01S15/8963

  using pulse inversion · CPC title

• G01S7/5202

  for pulse systems · CPC title

• G01S7/52038

  involving non-linear properties of the propagation medium or of the reflective target · CPC title

• A61B8/5207

  involving processing of raw data to produce diagnostic data, e.g. for generating an image · CPC title

• B06B1/0207

  Driving circuits (specially adapted for particular applications, see the relevant subclass, e.g. G01; circuits for steering transducer arrays G10K11/34; basic circuits H03) · CPC title