ULTRASOUND SYSTEM FOR CEREBRAL BLOOD FLOW IMAGING AND MICROBUBBLE-ENHANCED BLOOD CLOT LYSIS

• US 20100160779A1
• Filed: 08/03/2007
• Published: 06/24/2010
• Est. Priority Date: 08/11/2006
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Browning, Theodore J., Shi, William, Powers, Jeffry E., Gauthier, Thomas, Averkiou, Michalakis
• Granted Patent: US 9,630,028 B2
• Time in Patent Office: Days
• US Class Current: 600/439
• CPC Class Codes: A61B 17/22004 using mechanical vibrations, e.g. ultrasonic shock waves A61B17/225 takes precedence
• CPC Class Codes: A61B 2017/22014 the ultrasound transducer being outside patient's body; with an ultrasound transmission member; with a wave guide; with a vibrated guide wire not applied in A61B17/22012
• CPC Class Codes: A61B 2090/502 Headgear, e.g. helmet, spectacles
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/6814 Head
• 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 8/0808 for diagnosis of the brain
• CPC Class Codes: A61B 8/0816 using echo-encephalography
• CPC Class Codes: A61B 8/085 for locating body or organic structures, e.g. tumours, calculi, blood vessels, nodules
• CPC Class Codes: A61B 8/13 Tomography A61B8/10, A61B8/12 take precedence; tomography for radiation diagnosis A61B6/02
• CPC Class Codes: A61B 8/4227 characterised by straps, belts, cuffs or braces
• CPC Class Codes: A61B 8/4281 characterised by sound-transmitting media or devices for coupling the transducer to the tissue
• CPC Class Codes: A61B 8/481 involving the use of contrast agent, e.g. microbubbles introduced into the bloodstream analysis of echo signal exploiting properties of a contrast enhancer in devices for short-range imaging with acoustic waves G01S7/52039
• CPC Class Codes: A61B 8/483 involving the acquisition of a 3D volume of data
• CPC Class Codes: A61B 8/488 involving Doppler signals
• CPC Class Codes: A61N 2007/0021 Neural system treatment
• CPC Class Codes: A61N 2007/0039 using microbubbles
• CPC Class Codes: A61N 2007/0078 with multiple treatment transducers
• CPC Class Codes: A61N 2007/0082 Scanning transducers
• CPC Class Codes: A61N 2007/0095 : by modifying an excitation signal
• CPC Class Codes: A61N 7/00 : Ultrasound therapy lithotripsy A61B17/22, A61B17/225; massage using supersonic vibration A61H23/00 ; using ultrasound for introducing media into the body A61M37/0092
• CPC Class Codes: G01S 15/8981 : Discriminating between fixed and moving objects or between objects moving at different speeds, e.g. wall clutter filter
• CPC Class Codes: G01S 7/52041 : detecting modification of a contrast enhancer, e.g. detecting the destruction of a contrast agent by an acoustic wave, e.g. loss of correlation diagnostic techniques involving the use of contrast agents A61B8/481

Abstract

An ultrasonic diagnostic imaging system is described which utilizes one or more transducer arrays affixed to the head of a patient to diagnose and treat stroke victims. The transducer headset produces a two or three dimensional image of the vasculature inside the cranium, preferably assisted by a microbubble contrast agent. A vascular flow map is produced by the system which may be diagnosed for signs of a blood clot. If a blood clot is detected, a therapeutic beam is transmitted while the contrast agent is present to break up the blood clot by the disruption of microbubbles. The headset may also be used in a monitoring application to detect the recurrence of blood clots in a stroke victim.

Claims

1. A stroke therapy system for treating cranial vascular obstructions comprising:

a transducer array headset which maintains an ultrasonic transducer array in acoustic contact with the head of a subject;

an image processor, coupled to the ultrasonic transducer array, which produces images of blood flow in the cranium of the subject; and

an image display, coupled to the image processor, which produces an image of the cranial vasculature.

2. The stroke therapy system of claim 1, wherein the image processor comprises a Doppler processor,

wherein the Doppler processor produces at least one of velocity Doppler images or power Doppler images.

3. The stroke therapy system of claim 1, wherein the ultrasonic transducer array is further operable in a therapy mode to direct a therapeutic beam at an obstruction site in the cranium of the subject,

wherein the therapeutic beam comprises an ultrasonic beam which is capable of disrupting microbubbles at the obstruction site.

4. The stroke therapy system of claim 1, wherein the transducer array headset maintains a first ultrasonic transducer array in acoustic contact with one side of the head;

and

further comprising a second transducer array maintained in acoustic contact with the other side of the head by the headset.

5. A stroke therapy system for treating cranial vascular obstructions comprising:

a transducer array headset which maintains an ultrasonic transducer array in acoustic contact with the head of a subject;

an image processor, coupled to the ultrasonic transducer array, which produces images of blood flow in the cranium of the subject;

an image display, coupled to the image processor, which produces an image of the cranial vasculature;

a transmitter, coupled to the transducer array, which acts to cause the ultrasonic transducer array to transmit a therapeutic beam,

wherein imaging and delivery of the therapeutic beam are done by a common ultrasonic transducer array.

6. The stroke therapy system of claim 5, wherein imaging and delivery of the therapeutic beam are both done within the limits for diagnostic ultrasound energy delivery to a subject.

7. The stroke therapy system of claim 5, wherein the transmitter acts to apply at least one of pulse width modulated or duty cycle modulated signals to the transducer array.

8. The stroke therapy system of claim 5, wherein the transmitter further acts to cause the ultrasonic transducer array to transmit beams for at least one of Doppler or B mode imaging.

9. The stroke therapy system of claim 8, wherein the transmitter further acts to transmit beams for imaging over an image field exhibiting a given lateral dimension in the cranium,

wherein the therapeutic beam exhibits a lateral dimension which is less than the given lateral dimension.

10. The stroke therapy system of claim 8, wherein the transmitter further acts to transmit image beams over an image field occupying a given spatial region in the cranium,

wherein the therapeutic beam is transmitted over a portion of the given spatial region.

11. The stroke therapy system of claim 10, wherein the ultrasonic transducer array comprises a two dimensional array of transducer elements,

wherein the given spatial region is a volumetric region.

12. The stroke therapy system of claim 11, wherein the two dimensional array is maintained in acoustic contact with one side of the head;

further comprising a second two dimensional array maintained in acoustic contact by the headset with the other side of the head.

13. The stroke therapy system of claim 12, wherein the first two dimensional array scans imaging beams over a majority of the cranial distance between the left side of the head and the center of the cranium;

and

wherein the second two dimensional array scans imaging beams over a majority of the cranial distance between the right side of the head and the center of the cranium.

14. A method for treating stroke comprising:

applying a headset containing first and second transducer arrays to the head of a subject with the transducer arrays in acoustic contact with opposite sides of the head;

producing an ultrasound image of cranial flow from signals received from at least one of the transducer arrays;

securing the headset to maintain the transducer arrays in acoustic contact with the head;

infusing the blood stream of the subject with microbubbles; and

producing an ultrasound image of cranial flow containing microbubbles.

15. The method of claim 14, further comprising:

detecting a stenosis in the ultrasound image of cranial flow; and

directing a therapeutic ultrasound beam from at least one of the transducer arrays to microbubbles proximal to the stenosis.

16. The method of claim 15 wherein directing a therapeutic beam further comprises steering a pencil beam to microbubbles proximal to the stenosis.

17. The method of claim 15 wherein directing a therapeutic beam further comprises vibrating microbubbles proximal to the stenosis.

18. The method of claim 15 wherein directing a therapeutic beam further comprises breaking microbubbles proximal to the stenosis.

19. The method of claim 15, wherein directing a therapeutic ultrasound beam further comprises transmitting a therapeutic ultrasound beam to microbubbles proximal to the stenosis at an energy level which is within the limits for diagnostic ultrasound.

20. the method of claim 14, wherein applying further comprises applying a headset containing first and second two dimensional transducer arrays,

wherein producing an ultrasound image further comprises producing a three dimensional ultrasound image.