LOW POWER CONTINUOUS WAVE ULTRASOUND TRANSMITTER

• US 20100113934A1
• Filed: 10/30/2008
• Published: 05/06/2010
• Est. Priority Date: 10/30/2008
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: KOEN, Myron J., OGUZMAN, Ismail H.
• Granted Patent: US 8,193,683 B2
• Time in Patent Office: Days
• US Class Current: 600/459
• 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 that shunts positive transmitter output voltage to ground; and

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

the shunt transistors comprise control inputs that, when modulated, cause the shunt transistors to produce a continuous wave (“

CW”

) ultrasonic drive signal on a transmitter output.

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

a first CW control transistor coupled to the first shunt transistor; and

a second CW control transistor coupled to the second shunt transistor;

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

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

a pair of B-mode drive transistors that generates a B-mode ultrasonic drive pulse;

wherein both B-mode driver transistors are disabled to allow generation of a CW-mode ultrasonic drive signal.

4. The ultrasound transmitter of claim 2, 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.

5. The ultrasound transmitter of claim 2, wherein the CW control transistors and the shunt transistors are disabled to allow generation of a B-mode ultrasonic drive signal.

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

negative and positive high-voltage (“

HV”

) power supplies respectively coupled to first and second B-mode driver transistors; 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.

7. The ultrasound transmitter of claim 2, wherein the first shunt transistor and the second shunt transistor are alternately enabled to generate the CW ultrasonic drive signal.

8. A method, comprising:

enabling a continuous wave (“

CW”

) control transistor;

enabling a first CW drive transistor;

disabling a second CW drive transistor; and

providing a CW drive signal to an acoustic transducer.

9. The method of claim 8, further comprising:

disabling the first CW drive transistor; and

enabling the second CW drive transistor.

10. The method of claim 8, further comprising enabling a CW output drive signal, at least in part, by disabling a B-mode drive transistor.

11. The method of claim 8, 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.

12. The method of claim 8, further comprising:

disabling ultrasonic output by;

enabling the first and second CW drive transistors;

disabling the CW control transistor; and

disabling a B-mode drive transistor.

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

14. An ultrasound imaging system, comprising:

an ultrasonic signal receiver; and

an ultrasonic signal transmitter, comprising;

means for generating a continuous wave (“

CW”

) ultrasonic drive signal through a transmitter shunt transistor.

15. The ultrasound imaging system of claim 14, further comprising means for providing a CW power supply voltage to the transmitter shunt transistor.

16. The ultrasound imaging system of claim 14, further comprising means for protecting a CW control transistor from an ultrasonic drive voltage generated by a B-mode drive circuit.

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

18. The ultrasound imaging system of claim 14, wherein all CW-mode drive circuits are disabled during generation of a B-mode drive pulse.

19. The ultrasound imaging system of claim 14, wherein the means for generating an ultrasonic signal alternately enables each transistor of a pair of transmitter output shunt transistors.

20. The ultrasound imaging system of claim 14, 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.