Emboli detection in the brain using a transcranial doppler photoacoustic device capable of vasculature and perfusion measurement

• US 20140194740A1
• Filed: 11/01/2013
• Published: 07/10/2014
• Est. Priority Date: 01/07/2013
• Status: Abandoned Application

• Current Assignee: Cerebrosonics LLC
• Original Assignee: Cerebrosonics LLC
• Inventors: Pennypacker, Carl, Stein, Stuart
• Application Number:
  US14/070,264
• Publication Number:
  US 20140194740A1
• Time in Patent Office: Days
• US Class Current: 600/455
• CPC Class Codes: A61B 5/0042 for the brain
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• CPC Class Codes: A61B 5/4064 Evaluating the brain A61B5/031, A61B5/369, A61B5/14553 take precedence
• CPC Class Codes: A61B 5/6803 Head-worn items, e.g. helmets, masks, headphones or goggles
• 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 8/0808 for diagnosis of the brain
• CPC Class Codes: A61B 8/085 for locating body or organic structures, e.g. tumours, calculi, blood vessels, nodules
• CPC Class Codes: A61B 8/4227 characterised by straps, belts, cuffs or braces
• CPC Class Codes: A61B 8/488 involving Doppler signals
• CPC Class Codes: A61B 8/565 involving data transmission via a network
• CPC Class Codes: A61B 8/582 Remote testing of the device

Abstract

A device, method, and system for detecting emboli in the brain is disclosed. A transcranial Doppler photoacoustic device transmits a first energy to a region of interest at an internal site of a subject to produce an image and blood flow velocities of a region of interest by outputting an optical excitation energy to said region of interest and heating said region, causing a transient thermoelastic expansion and produce a wideband ultrasonic emission. Detectors receive the wideband ultrasonic emission and then generate an image of said region of interest from said wideband ultrasonic emission. A Doppler ultrasound signal will also be deployed to image the region of interest. Doppler presents changes in velocity to map blood flow. Additionally, a dye can be given to visualize the brain vasculature and a perfusion measurement can be made in various regions of the brain along with the transcranial Doppler and the photoacoustic screening. Systems are taught using resultory medical data for better triage within an enhanced stroke ecosystem.

Claims

1. A device for detecting emboli in the brain comprising, in combination:

an array of ultrasound transducers;

actuators coupled to the array of ultrasound transducers;

said actuators enabled to alter, skew, move, rotate, or change the position of the transducers;

said actuators enabled to be controlled remotely; and

the array of ultrasound transducers having the ability to learn and send Doppler shifted signals, regarding blood flow from brain and neck vasculatures, to a remote site.

2. The device according to claim 1, further comprising:

means for wireless remote control capability and remote manipulation of the ultrasound transducers; and

means for wireless transmission and receipt of the Doppler signals over internet, radio, land links, and related systems.

3. The device according to claim 1, wherein the array of ultrasound transducers are mounted on x-y position stages and two angular pointing stages.

4. The device according to claim 3, wherein the ultrasound transducer'"'"'s x-y and two angle positions can be controlled from a remote location via the internet, radio, land links, and related systems.

5. The device according to claim 1, wherein the actuators comprise robotic arms or other robotic manipulation systems that enable an ultrasound transducer to:

move in space, approach and make contact with the patient'"'"'s head, and begin searching for arterial Doppler signals.

6. The device according to claim 1, wherein the array of ultrasound transducers are single channel or phased.

7. The device according to claim 1, further comprising means for making a 3-dimensional model of the blood flow of the brain, using at least a Super-resolution algorithm and angular positions from an ultrasound transducer encoder and a signal return time from a vasculature.

8. The device according to claim 7, wherein remote control of the ultrasound transducers is done by way of feedback signals, from the device to the remote center and from the remote center to the device, in raw or analyzed form.

9. The device according to claim 1, further comprising ultrasound impedance matching inserts.

10. The device according to claim 9, wherein the ultrasound impedance matching inserts comprise:

materials made of intermediate sonic indices of refraction;

disposable materials (i.e. the insert as a whole itself is disposable); and

a smooth surface enabling the transducers to move, friction-free, over the surface of a patient'"'"'s skull.

11. The device according to claim 1, further comprising a convex probe array used to image vessels from one position, for carotid artery insonation.

12. The device according to claim 1, wherein the ultrasound transducers comprise Transcranial Ultrasound Transducers.

13. The device according to claim 12, wherein the ultrasound transducers further comprise Carotid Doppler Ultrasound Transducers.

14. A device according to claim 13, wherein the Carotid Doppler Ultrasound Transducers comprise:

a B mode;

pulsed wave;

color flow monitoring;

power Doppler;

M mode;

automatic measurement;

triplex mode with B mode;

Pulsed Doppler; and

Color mode in real time.

15. A method for detecting emboli in the brain and sending the relevant data to a remote site which comprises, in combination:

configuring an ultrasound array to transmit a beam pattern sufficient to isonate a region of interest at an internal site of a subject;

finding, creating, and displaying maps or images of said region of interest;

identifying acute occlusion or stenosis in major brain and neck arteries;

wirelessly transmitting data identified to a remote site; and

wirelessly receiving information about data identified from the remote site at the site of the subject where the device is being used.

16. The method according to claim 15, wherein configuring an ultrasound array to transmit a beam pattern sufficient to insonate a region of interest at an internal site of a subject, said method comprises the steps of:

a) providing an array of ultrasound transducer elements;

b) outputting a beam pattern from said array of ultrasound transducer elements to insonate a region of interest at an internal site in a body that is sufficiently large that the beam output pattern comprises a multi-beam pattern,

insonating multiple receiver elements over a substantially simultaneous period by directing energy produced by said array of ultrasound transducer elements into said region of interest in said body, and

adjusting an amplitude of energy output by said array of transducers to cause the beam pattern output to have a generally flat upper pattern, nulling in a grating lobe region; and

,

c) introducing a propagation time delay of the beam pattern output from said array of ultrasound transducer elements, wherein the propagation delay increases as a distance increases from a central output area of said array of ultrasound transducer elements.

17. The method according to claim 16, wherein the transmission of said array of transducer elements is configured in step b) comprising a beam pattern output by said array of transducer elements propagating from a point source having a focal distance located behind said array of transducer elements when viewed from said region of interest.

18. The method according to claim 16, wherein step b) further comprises adjusting a duty cycle of one or more pulses output by at least one transducer element of said array of transducer elements.

19. The method according to claim 16, wherein step b) comprises adjusting a quantity of pulses output by at least one transducer element of said array of transducer elements.

20. The method according to claim 17, wherein step b) further comprises adjusting a quantity of pulses output by said at least one transducer element of said array of transducer elements.

21. The method according to claim 16, wherein said array of transducer elements comprises an 8×

8 array.

22. A method of configuring an ultrasound array to transmit a beam pattern sufficient to insonate a region of interest at an internal site of a subject, said method comprising, in combination:

a) providing an array of ultrasound transducer elements;

b) outputting a beam pattern from said array of ultrasound transducer elements to insonate a region of interest at an internal site in a body sufficiently large that the beam pattern comprises a multi-beam pattern,

insonating multiple receiver elements over a substantially simultaneous period by directing energy produced by said array of ultrasound transducer elements into said region of interest in said body, and

adjusting an amplitude of energy output by said array of transducers to cause the beam pattern output to have a generally flat upper pattern and nulling in a grating lobe region; and

,

c) introducing a phase shift of the beam pattern output from said array of ultrasound transducer elements, wherein a degree of phase shift increases as a distance increases from a central output area of said array of ultrasound transducer elements.

23. The method according to claim 22, comprising:

moving the ultrasound transducer elements across the skull without extending the transducers in any direction abnormal or unparallel to the skull; and

,

enabling the transducer to turn 90 degrees within its cable.

24. A method of configuring an ultrasound array to transmit a beam pattern sufficient to insonate a region of interest at an internal site of a subject, said method comprising the steps of:

a) providing an array of ultrasound transducer elements;

b) outputting a beam pattern from said array of ultrasound transducer elements to insonate a region of interest at an internal site in a body sufficiently large that the beam pattern comprises a multi-beam pattern,

insonating multiple receiver elements over a substantially simultaneous period by directing energy produced by said array of ultrasound transducer elements into said region of interest in said body, and

adjusting an amplitude of energy output by said array of transducers to cause the beam pattern output to have a generally flat upper pattern and nulls in a grating lobe region; and

,

c) introducing a phase shift of the beam pattern output from said array of ultrasound transducer elements, wherein a degree of phase shift increases as a distance increases from a central output area of said array of ultrasound transducer elements.

25. The method according to claim 24, wherein the transmission of said array of transducer elements is configured in step b) such that the beam pattern output by said array of transducer elements appears to propagate from a point source having a focal distance located behind said array of transducer elements when viewed from said region of interest.

26. The method according to claim 24, wherein step b) further includes adjusting a duty cycle of one or more pulses output by at least one transducer element of said array of transducer elements.

27. The method according to claim 24, wherein step b) includes adjusting a quantity of pulses output by at least one transducer element of said array of transducer elements.

28. The method according to claim 24, wherein said array of transducer elements comprises an 8×

8 array.

29. A method for operating an array of ultrasound transducer elements, wherein:

the element spacing in the array is greater than, equal to or less than a half wavelength of the ultrasound energy produced by the elements, and

wherein the array is used differently in transmit and receive modes, comprising;

forming a transmit beam from a position external to a region of interest encompassing a plurality of receive beams and initially acquiring a signal by insonating a target region comprising multiple receive beam positions over a substantially simultaneous period;

receiving data from the multiple receive beam positions of the array;

combining the received data in a processor;

locking onto the receive beam and the point(s) producing a peak signal; and

correcting for motions in the target region by periodically forming multiple receive beams and re-acquiring the peak signal.

30. The method of claim 29, additionally comprising forming a transmit beam using a sub-array of the array.

31. The method of claim 29, wherein the large target region is a 3-D spatial region.

32. The method of claim 29, wherein the transmit beam uniformly insonates over a 2-D transmitter sub-aperture.

33. The method of claim 29, wherein the transmit beam has a fixed focus.

34. The method of claim 29, additionally comprising simultaneously and digitally forming multiple receive beams for receiving data.

35. The method of claim 29, additionally comprising Doppler processing the received data.

36. The method of claim 29, wherein the array is a monostatic array, and additionally comprising transmitting from the full aperture and scanning the transmitted beam over the region being examined.

37. The method of claim 29, further comprising using a transmitter diversity technique to spread temporal intensity over the face of the array.

38. The method of claim 37, comprising using a different transmit sub-aperture for different coherent burst of pulses.

39. The method of claim 29, further comprising steering the receive beams to a point or points that produce a peak signal.

40. The method of claim 39, wherein the peak signal is a maximum amplitude at high Doppler frequencies.

41. The method of claim 29, further comprising steering the receive beams using a phase steering or time-delay steering technique.

42. The method of claim 29, further comprising providing the array of ultrasound transducer elements on a low-profile easily-attached transducer patch.

43. The method of claim 29, further comprising determining spatial coordinates of received data,

measuring a velocity of the blood flow in each frequency;

collecting a data point of said velocity;

measuring a velocity of the blood flow at the next frequency; and

making a plot of the velocity in the resolution element.

44. The method of claim 43, further comprising forming and displaying a 3D map based on the spatial coordinates of received data.

45. The method of claim 43, wherein the received data comprises time delay to the reflected signal, the velocity of the structures, and the angular positions of the structures.

46. The method of claim 43 wherein the data could be collected and received from one transducer or multiple transducers.

47. The method of claim 46 wherein each transducer comprises:

a characteristic angle;

a characteristic Doppler shift; and

a characteristic depth for each artery detected.

48. The method of claim 46 wherein:

the data from multiple transducers comprise depth data and Doppler shift data; and

,

the data are combined to form a best fit model of the brain vasculature.

49. The method of claim 48, wherein the data can be fit to a template image of a typical brain vasculature via at least squared minimization way, or maximum likelihood, or other like procedure.

50. The method of claim 49, wherein the template image would take into consideration, varying sizes of patient'"'"'s skulls and vascular positions via a method comprising:

finding major brain and neck arteries first; and

,

using the major brain and neck arteries findings to discover and find smaller vasculatures.

51. The method of claim 29, further comprising tracking of arteries capabilities comprising the method of:

scanning the ultrasound transducer in various directions and angles; and

,

following the angle of maximum signal.

52. The method of claim 29, further comprising a scan mode of super resolution comprising:

stepping the transducers at a fraction of resolution element (ex;

1/10 of resolution element);

fitting the resulting signal to a “

super-resolution image”

of the acquired signals (ex;

of the acquired 10 signals); and

making a measurement of the width of the velocity distribution in one normal resolution element/voxel.

53. The method of claim 52, wherein the measuring of the width of the velocity distribution in one normal resolution element/voxel, comprises the method of:

measuring a velocity of the blood flow in each frequency;

collecting a data point of said velocity;

measuring a velocity of the blood flow at the next frequency; and

making a plot of the velocity in the resolution element.

54. The method of claim 53 wherein velocity fields are coupled with pulse modulation data to determine characteristics of vasculatures in various regions of the brain.

55. The method of claim 29, further comprising forming and displaying a map of the skull thickness at a given x-y position on the skull.

56. The method of claim 51, wherein computing the skull thickness comprises finding a time delay and converting it to compute the thickness of the skull at that point.

57. The method of claim 51, further comprising alternately using a tone or other audible or visual means such as acoustic impedance or electronic detection of specific chirp) to find skull thickness via remote operator (i.e. operators at a remote site).

58. The method of claim 52, wherein finding a time delay comprises:

measuring a first pulse from an initial reflection of a pulse from the ultrasound transducer; and

measuring a first pulse from the second reflection of the pulse when the transducer pulse exits the skull bone and enters the brain.

59. The method of claim 29, further comprising finding and using the path through the skull with the least amount of bone material when a large angle is needed to reach a vasculature.

60. The method of claim 29, further comprising a method for setting up and measuring an absolute reference frame upon the head:

understanding the exact position on the head and relative to the head using signals from multiple transducers and reflection signals;

discovering our position on the skull;

measuring time delays between the other transducers; and

constantly finding and monitoring the exact placement of the head frame at all times.

61. The method of claim 29, further comprising time-tagging every signal received or sent from the transducers, thus enabling an absolute and stable reference frame to less than at least about one millimeter accuracy.

62. The method of claim 29 further comprising:

at least a Signal Averaging Mode which comprises the method of;

determining the angular positions by determining the angles of the ultrasound transducers and the super-resolution position; and

accumulating data for every resolution element in the brain.

63. The method of claim 29 further comprising insonating positions of interests for longer periods until a signal is built up against a background.

64. The method of claim 29 further comprising enhancing signal to noise by successively scanning over regions of interest with super resolution.

65. The method of claim 29 wherein the signal to noise increases approximately proportional to the square-root number of scans or the square-root of time.

66. A data reduction and analysis system wherein actuators coupled to ultrasound transducers can be remotely manipulated, over the Internet or radio or land links, with control taking place at a remote site distal from the patient.

67. The system according to claim 66 wherein said actuators may comprise robotic arms or other robotic manipulation systems that enable a TCD probe to move in space, approach and make gentle contact with the patient'"'"'s head, and begin searching for arterial doppler signals.

68. The system according to claim 66 further comprising means to:

make maps of brain vasculatures;

identify acute occlusion or stenosis in major brain and neck arteries;

remotely send the data identified, to a remote site; and

provide capabilities to quickly analyze the data identified and advise diversion of the patient to a primary or comprehensive stroke center upon finding of a collusion in major arteries or blockages of the carotid or major cerebral or vertebral arteries.

69. A method to detect prostate cancer, comprising, in combination:

injecting ICN-pSMA molecule to the prostate area which combines with the surface of Prostate Cancer cells, and liberates ICN in the process;

insonating the prostate and the adjacent vicinity with energy from a phased array Doppler device;

insonating the prostate and the adjacent vicinity with energy from a photoacoustic device; and

detecting the spectrum of a plurality of ICN molecules in the region of the Cancer.