Low power continuous wave ultrasound transmitter

• US 8,193,683 B2
• Filed: 10/30/2008
• Issued: 06/05/2012
• Est. Priority Date: 10/30/2008
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Oguzman, Ismail H., Koen, Myron J.
• Primary Examiner(s): Dougherty, Thomas
• Application Number:
  US12/261,185
• Publication Number:
  US 20100113934A1
• Time in Patent Office: 1,314 Days
• Field of Search: 310/317
• US Class Current: 310/317
• CPC Class Codes: A61B 8/4483 characterised by features of the ultrasound transducer
• CPC Class Codes: B06B 1/023 and stepped in amplitude, e.g. square wave, 2-level signal
• CPC Class Codes: G01S 15/8979 Combined Doppler and pulse-echo imaging systems
• CPC Class Codes: G01S 7/5202 for pulse systems

Abstract

A system and method for providing a continuous wave (“CW”) ultrasonic drive signal and a B-mode ultrasonic drive signal from an ultrasonic transmitter are disclosed herein. An ultrasonic transmitter includes a first shunt transistor and a second shunt transistor. The first shunt transistor shunts positive transmitter output voltage to ground. The second shunt transistor shunts negative transmitter output voltage to ground. The shunt transistors include control inputs that, when modulated, cause the shunt transistors to produce a CW ultrasonic drive signal on a transmitter output. The ultrasonic transmitter also includes a first CW control transistor coupled to the first shunt transistor, and a second CW control transistor coupled to the second shunt transistor. The first and second CW control transistors respectively provide negative and positive CW drive voltage to the first and second shunt transistors.

Claims

1. An ultrasound transmitter, comprising:

a first shunt transistor, coupled to a first signal, that shunts positive transmitter output voltage to ground;

a first continuous wave CW control transistor coupled to the first shunt transistor and a first continuous wave control signal;

a second shunt transistor, coupled to a second signal, that shunts negative transmitter output voltage to ground;

a second continuous wave CW control transistor coupled to the second shunt transistor and a second continuous wave control signal; and

the shunt transistors comprise control inputs that, when modulated, cause the shunt transistors to produce a continuous wave ultrasonic drive signal on a transmitter output;

wherein the first and second CW control transistors respectively provide negative and positive CW drive voltage to the first and second shunt transistors.

2. The ultrasound transmitter of claim 1, further comprising:

a pair of B-mode drive transistors Q1 (202) and Q2 (204) coupled to the first and second shunt transistors that generates a B-mode ultrasonic drive pulse;

wherein both B-mode driver transistors Q1 (202) and Q2 (204) are disabled to allow generation of a CW-mode ultrasonic drive signal.

3. The ultrasound transmitter of claim 1, further comprising:

a first rectifying device coupled from the first shunt transistor and the first CW control transistor to ground; and

a second rectifying device coupled from the second shunt transistor and the second CW control transistor to ground.

4. The ultrasound transmitter of claim 1, wherein the CW control transistors and the shunt transistors are disabled by a pair of B-mode driver transistors Q1 (202) and Q2 (204) to allow generation of a B-mode ultrasonic drive signal.

5. The ultrasound transmitter of claim 1, further comprising:

negative and positive high-voltage (“

HV”

) power supplies respectively coupled to first and second B-mode driver transistors Q1 (202) and Q2 (204); and

negative and positive CW power supplies respectively coupled to the first and second CW control transistors;

wherein the CW power supply output voltages are lower that the HV power supply output voltages.

6. The ultrasound transmitter of claim 1, wherein the first shunt transistor and the second shunt transistor are alternately enabled to generate the CW ultrasonic drive signal.

7. A method, comprising:

enabling a first continuous wave (“

CW”

) control transistor coupled to a CW voltage allowing a current to flow to a first CW drive transistor coupled to the CW control transistor;

enabling the first CW drive transistor to drive the CW voltage onto an output;

disabling a second CW drive transistor coupled to the output and a second CW control transistor; and

providing a CW ultrasonic drive signal to an acoustic transducer via the output.

8. The method of claim 7, further comprising:

disabling the first CW drive transistor; and

enabling the second CW drive transistor.

9. The method of claim 7, further comprising enabling a CW output drive signal, at least in part, by disabling a pair of B-mode drive transistors Q1 (202) and Q2 (204).

10. The method of claim 7, further comprising enabling a B-mode output drive signal, at least in part, by disabling the first and second CW drive transistors and the CW control transistor.

11. The method of claim 7, further comprising:

disabling ultrasonic output by;

enabling the first and second CW drive transistors;

disabling the CW control transistors; and

disabling a pair of B-mode drive transistors Q1 (202) and Q2 (204) coupled to the output.

12. The method of claim 11, further comprising shunting voltage on an ultrasonic transmitter output to ground through the CW drive transistors.

13. An ultrasound imaging system, comprising:

an ultrasonic signal receiver coupled to a transducer system and a signal processor, the transducer system for converting a plurality of detected waves into electrical signals;

an ultrasonic signal transmitter coupled to the transducer system, said transmitter comprising;

means for generating a continuous wave (“

CW”

) ultrasonic drive signal through a transmitter shunt transistor;

means coupled to a CW power supply voltage and to the shunt transistor for providing the CW power supply voltage to the transmitter shunt transistor; and

means for protecting a CW control transistor coupled to the shunt transistor from an ultrasonic drive voltage generated by a B-mode drive circuit coupled to the shunt transistor.

14. The ultrasound imaging system of claim 13, wherein all B-mode drive circuits are disabled during generation of the CW ultrasonic drive signal.

15. The ultrasound imaging system of claim 13, wherein all CW-mode drive circuits are disabled during generation of a B-mode drive pulse.

16. The ultrasound imaging system of claim 13, wherein the means for generating an ultrasonic signal alternately enables each transistor of a pair of transmitter output shunt transistors.

17. The ultrasound imaging system of claim 13, wherein a means for providing a B-mode power supply voltage to a B-mode ultrasonic driver is separate from the means for providing a CW power supply voltage to the transmitter shunt transistor.