Integrated bias circuitry for ultrasound imaging devices configured to image the interior of a living being

• US 7,967,754 B2
• Filed: 10/14/2004
• Issued: 06/28/2011
• Est. Priority Date: 10/14/2004
• Status: Expired due to Fees

• Current Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Knight, Jon M.
• Primary Examiner(s): Le; Long V
• Assistant Examiner(s): Rozanski; Michael T
• Application Number:
  US10/966,594
• Publication Number:
  US 20060084875A1
• Time in Patent Office: 2,448 Days
• Field of Search: 600/437, 600/459, 600/447, 600460-471, 128/661, 367/138, 367/153
• US Class Current: 600/459
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: B06B 1/0292 Electrostatic transducers, e.g. electret-type
• CPC Class Codes: G01S 15/8906 Short-range imaging systems; Acoustic microscope systems using pulse-echo techniques

Abstract

The systems and methods described herein allow for the application of a bias voltage to one or more transducers implemented within a medical ultrasound imaging system. Bias circuitry is placed within an imaging device and used to apply a DC bias to one or more transducers requiring a DC bias to operate. The one or more transducers can be fabricated in a semiconductor manufacturing process and integrated with the bias circuitry on a common semiconductor substrate. Also provided is a method for operating the one or more transducers and bias circuitry using a communication channel having two signal lines.

Claims

1. A medical imaging system, comprising:

an imaging device configured to be insertable into an intravascular portion of a living being and to image the interior of the living being, the imaging device comprising;

an ultrasound transducer; and

bias circuitry electrically coupled with the transducer and configured to electrically bias the transducer;

a driveshaft coupled to the imaging device and configured and arranged for rotating the imaging device; and

a signal line located along the driveshaft and coupled to both the ultrasound transducer and the bias circuitry and configured and arranged for delivery of both a transducer drive signal to the transducer and a charge to the bias circuitry;

wherein the transducer includes a capacitive micromachined ultrasound transducer (CMUT) and the bias circuitry is integrated with the CMUT on a common semiconductor substrate.

2. The system of claim 1, further comprising an image processing system communicatively coupled with the imaging device.

3. The system of claim 2, wherein the imaging device is communicatively coupled with the image processing system with an inductive coupling.

4. The system of claim 3, wherein the image processing system is configured to output the transducer drive signal to the transducer and provide the charge to the bias circuitry over the signal line.

5. The system of claim 2, wherein the image processing system is configured to output the transducer drive signal to the transducer via the signal line during a first time period, receive an echo signal during a second time period and output a bias signal to the bias circuitry via the signal line during a third time period, wherein the first time period, the second time period, and the third time period are in a single imaging cycle.

6. The system of claim 5, wherein the signal line is inductively coupled to the image processing system and the bias signal is a series of DC pulses.

7. The system of claim 5, wherein the bias circuitry comprises a charge pump and the amplitude of the bias signal is below an excitement threshold for the transducer.

8. The system of claim 7, wherein the image processing system is further configured to output the bias signal during a fourth time period, longer than the third time period and prior to the first time period.

9. The system of claim 8, wherein the bias signal output during the fourth time period is configured to initialize the charge pump.

10. The system of claim 1, wherein the transducer is one of a plurality of transducers within a transducer array.

11. The system of claim 1, wherein the bias circuitry comprises a charge pump.

12. The system of claim 11, wherein the imaging device comprises rectification circuitry.

13. The system of claim 1, wherein the bias circuitry is configured to control the bias voltage.

14. The system of claim 13, wherein the bias circuitry comprises charge limiting circuitry configured to control the bias voltage.

15. The system of claim 13, wherein the transducer is one of a plurality of transducers within a transducer array.

16. A intravascular ultrasound imaging system, comprising:

an image processing system configured to output a transducer drive signal during a first time period, receive an echo signal during a second time period and output a bias signal during a third time period, wherein the second time period is after the first time period and the third time period is after the second time period, wherein the first time period, the second time period, and the third time period are in a single imaging cycle;

wherein the transducer drive signal is configured to cause a transducer to generate an ultrasound pulse, the echo signal is representative of an echo received by the transducer and the bias signal is configured to provide electrical charge to transducer bias circuitry.

17. The system of claim 16, wherein the bias signal is a DC signal.

18. The system of claim 17, wherein the bias signal is a series of DC pulses.

19. The system of claim 18, wherein the amplitude of the bias signal is below an excitement threshold for the transducer.

20. The system of claim 16, wherein the image processing system is further configured to output the bias signal during a fourth time period, longer than the third time period and prior to the first time period.

21. The system of claim 20, wherein the bias signal output during the fourth time period is configured to initialize a charge pump.

22. A method of intravascular ultrasound imaging with an image processing system, comprising:

outputting a first signal during a first time period, wherein the first signal is configured to cause a transducer to transmit an ultrasound pulse;

receiving a second signal during a second time period following the first time period, wherein the second signal is representative of an echo received by the transducer; and

outputting a bias signal during a third time period following the second time period, wherein the bias signal is configured to provide charge to bias circuitry, wherein the first time period, the second time period, and the third time period are in a single imaging cycle.

23. The method of claim 22, further comprising outputting a second bias signal during a fourth time period prior to the first time period, wherein the second bias signal output during the fourth time period is configured to initialize the bias circuitry.

24. The method of claim 23, wherein the fourth time period is longer than the third time period.

25. The method of claim 22, wherein the bias signal is a DC signal.

26. The method of claim 22, wherein the bias signal is a series of DC pulses.

27. The method of claim 22, wherein the amplitude of the bias signal is maintained below an excitement threshold of the transducer.