Intraocular Ultrasound Doppler Techniques

• US 20080319319A1
• Filed: 04/14/2008
• Published: 12/25/2008
• Est. Priority Date: 04/12/2007
• Status: Active Grant

• Current Assignee: Doheny Eye Institute
• Original Assignee: Doheny Eye Institute
• Inventors: Humayun, Mark S., Zhou, Qifa, Shung, K. Kirk, Chader, Gerald, Xu, Xiaochen, Ameri, Hossein
• Granted Patent: US 8,684,935 B2
• Time in Patent Office: Days
• US Class Current: 600/454
• CPC Class Codes: A61B 5/6848 Needles
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61B 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61B 8/10 Eye inspection
• 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: A61B 8/483 involving the acquisition of a 3D volume of data
• CPC Class Codes: A61F 2009/00863 Retina
• CPC Class Codes: A61F 9/008 using laser
• CPC Class Codes: G01F 1/663 by measuring Doppler frequency shift

Abstract

Systems and methods are disclosed providing for the use of ultrasound energy to measure blood flow within blood vessels by Doppler velocity measurement. Directional high-frequency pulsed-wave Doppler measurements can be made with a suitable ultrasonic needle transducers for in vivo measuring of blood flow. A needle probe can include a ultrasonic material such as PMN-PT. Such blood flow measurements can be made in any part of the body, e.g., in the central retinal vein and branch retinal veins.

Claims

1. A system comprising:

an ultrasound probe including an ultrasonic transducer for producing an output of ultrasound energy, the probe being configured and arranged for insertion in a patient;

a control unit connected to the ultrasound transducer and configured and arranged to control the production of ultrasound energy from the transducer; and

a measurement unit configured and arranged to measure blood flow within blood vessels by Doppler velocity measurement.

2. The system of claim 1, wherein the ultrasound transducer comprises a flat, angled or beveled tip.

3. The system of claim 1, wherein the ultrasonic transducer comprises a piezoelectric material.

4. The system of claim 3, wherein the piezoelectric material comprises PMN-PT.

5. The system of claim 1, wherein the ultrasound transducer includes a cylindrical housing.

6. The system of claim 5, wherein the cylindrical housing comprises steel.

7. The system of claim 6, wherein the steel comprises stainless steel.

8. The system of claim 5, further comprising a flexible tube disposed within the cylindrical housing.

9. The system of claim 8, wherein the flexible tube comprises polyimide.

10. The system of claim 4, wherein the PMN-PT comprises PMN-33% PT.

11. The system of claim 1, wherein the control unit comprises timing circuitry and a power amplifier.

12. The system of claim 1, wherein the control unit is configured and arranged to control the intensity of the output.

13. The system of claim 1, wherein the control unit is configured and arranged to control the pulse repetition frequency (PRF) of the output.

17. The system of claim 1, wherein the transducer and controller are configured and arranged to produce ultrasonic energy at a frequency of about 1 MHz to about 50 MHz.

18. The system of claim 1, wherein the controller is configured and arranged to produce a pulse repetition frequency of about 100 Hz to about 100 kHz.

19. The system of claim 1, wherein the controller is configured ad arranged to produce a pulse cycle count from 1 to 255.

20. A method of measuring blood flow in a blood vessel, the method comprising:

inserting a needle probe with an ultrasonic transducer into a patient;

placing the transducer over blood vessels and/or tissue in a patient'"'"'s body;

producing ultrasonic energy from the transducer;

directing the ultrasonic energy to the blood vessels; and

measuring blood flow within blood vessels by Doppler velocity measurement.

21. The method of claim 20, wherein measuring blood flow within blood vessels includes measuring blood velocity.

22. The method of claim 20, further comprising measuring volumetric flow rate.

23. The method of claim 20, further comprising coupling the needle probe to a surgical instrument or component.

24. The method of claim 23, wherein the surgical instrument or component comprises an endoscope, a laser probe, a cryoprobe, a light fiber, and/or an optical coherence tomography probe.

25. The method of claim 20, further comprising receiving ultrasonic energy reflected from the targeted blood vessels.

26. The method of claim 20, wherein the ultrasonic transducer comprises PMN-PT.

27. The method of claim 20, wherein producing ultrasonic energy from the transducer comprises producing ultrasonic energy at a frequency of about 1 MHz to about 50 MHz.

28. The method of claim 20, wherein the ultrasonic energy is produced at a frequency of about 44 MHz to about 24 MHz.

29. The method of claim 20, wherein producing ultrasonic energy from the transducer comprises producing a pulse repetition frequency of about 100 Hz to about 100 kHz.

30. The method of claim 20, wherein producing ultrasonic energy from the transducer comprises producing a pulse cycle count from 1 to 255.

31. The method of claim 20, wherein producing ultrasonic energy from the transducer comprises using a piezoelectric needle probe.

32. The method of claim 20, wherein inserting the needle probe into a patient comprises inserting the needle probe into the patient'"'"'s eye.

33. The method of claim 32, wherein placing the transducer over blood vessels and/or tissue in a patient'"'"'s body comprises placing the transducer over or adjacent to retinal vessels of the eye or the optic nerve of the patient.