LINEAR MAGNETIC DRIVE TRANSDUCER FOR ULTRASOUND IMAGING

• US 20130345566A1
• Filed: 05/09/2013
• Published: 12/26/2013
• Est. Priority Date: 05/09/2012
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Kruger, Grant, Rubin, Jonathan, Weitzel, William, Thelen, Brian, Koziol, Leo, Brook, Robert, Mitra, Mainak
• Granted Patent: US 10,517,569 B2
• Time in Patent Office: Days
• US Class Current: 600/445
• CPC Class Codes: A61B 8/0891 for diagnosis of blood vessels
• CPC Class Codes: A61B 8/4427 Device being portable or laptop-like
• CPC Class Codes: A61B 8/4461 Features of the scanning mechanism, e.g. for moving the transducer within the housing of the probe
• CPC Class Codes: A61B 8/4472 Wireless probes
• CPC Class Codes: A61B 8/4483 characterised by features of the ultrasound transducer
• CPC Class Codes: A61B 8/461 Displaying means of special interest
• 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: A61B 8/56 Details of data transmission or power supply
• CPC Class Codes: G01N 29/222 Constructional or flow details for analysing fluids optoacoustic fluid cells G01N29/2425
• CPC Class Codes: G01S 15/8915 using a transducer array
• CPC Class Codes: G01S 15/8945 using transducers mounted for linear mechanical movement
• CPC Class Codes: G01S 15/8995 Combining images from different aspect angles, e.g. spatial compounding
• CPC Class Codes: G01S 7/003 Transmission of data between radar, sonar or lidar systems and remote stations
• CPC Class Codes: G01S 7/52042 determining elastic properties of the propagation medium or of the reflective target diagnostic techniques involving the measurement of strain A61B8/485
• CPC Class Codes: G01S 7/52065 Compound scan display, e.g. panoramic imaging

Abstract

An ultrasound imaging system uses a magnetic linear motor driven ultrasound scanner, with accurate track and hold operation and/or other motion feedback, to scan a two dimensional or three dimensional area of a sample. The scanner is implemented in a low-power and low-bandwidth handheld device and is connected with a remote image processing system that receives raw data and performs full ultrasound image analysis and creation, allowing the handheld to be used for scanning, pre-processing, and display.

Claims

1. An ultrasound scanning device for providing real-time two-dimensional scan data of a sample area, the scanning device comprising:

a linear magnetic drive assembly defining a first scanning direction of freedom for moving an actuator of the magnetic drive assembly along a linear path;

an ultrasound transducer mounted to the actuator of the linear magnetic drive assembly to scan along the linear path, in response to drive signals provided to the linear magnetic drive assembly, wherein the ultrasound transducer is to provide ultrasound scanning over a first scan plane corresponding to the sample area and extending below a surface contact area for the scanning device; and

a magnetic drive assembly controller coupled to the linear magnetic drive assembly and the ultrasound transducer and applying a control for the drive signals sent to the linear magnetic drive assembly and having a sensor coupled to determine position of the ultrasound transducer during scanning of the sample area, the magnetic drive assembly controller forming a closed-loop control of the linear magnetic drive assembly and the ultrasound transducer.

2. The ultrasound scanning device of claim 1, wherein the linear magnetic drive assembly defines a second scanning direction of freedom, different than the first scanning direction of freedom, to scan within the first scan plane.

3. The ultrasound scanning device of claim 1, wherein the ultrasound transducer defines a second scanning direction of freedom, different than the first scanning direction of freedom, to scan within the first scan plane.

4. The ultrasound scanning device of claim 2 or 3, wherein the second scanning direction of freedom is scanned electrically or mechanically.

5. The ultrasound scanning device of claim 4, the magnetic drive assembly controller is to scan the ultrasound transducer in the first scan plane to effect one of either Doppler velocity data, pulse-echo ultrasound data for radio-frequency tracking, or B mode data over the first scan plane.

6. The ultrasound scanning device of claim 1, wherein the linear magnetic drive assembly defines a second scanning direction of freedom, different than the first scanning direction of freedom, to scan within a second plane, different from the first scan plane for obtaining three-dimensional scan data.

7. The ultrasound scanning device of claim 1, wherein the ultrasound transducer defines a second scanning direction of freedom, different than the first scanning direction of freedom, to scan within a second plane, different from the first scan plane for obtaining three-dimensional scan data.

8. The scanning device of claim 1, wherein magnetic drive assembly comprises a magnetic actuated coil assembly.

9. The scanning device of claim 1, wherein the ultrasound transducer is a piezoelectric transducer.

10. The scanning device of claim 1, wherein the ultrasound transducer is a Capacitive Micromachined Ultrasonic Transducers (CMUT) transducer.

11. The scanning device of claim 1, wherein the ultrasound transducer is a single element transducer.

12. The scanning device of claim 1, wherein the ultrasound transducer is a multiple-element transducer, wherein each of the elements is aligned along the linear path during scanning.

13. The scanning device of claim 1, wherein the ultrasound transducer is mounted on a swivel base of the actuator or another base having a second scanning direction of freedom different than the first scanning direction of freedom, such that the ultrasound transducer is aligned for scanning along the linear path during scanning and has an orientation that changes in response to the swivel base or another base to scan at different angles during scanning along the linear path, wherein the orientation changes are either actively induced or passively induced.

14. The scanning device of claim 1, wherein the linear path is a rectilinear path.

15. The scanning device of claim 1, wherein the linear path is a curvilinear path.

16. The scanning device of claim 1, wherein the sensor of the magnetic drive assembly controller determines position and orientation of the ultrasound transducer.

17. The scanning device of claim 1, wherein the sensor of the magnetic drive assembly controller determines position by sensing a physical characteristic of the ultrasound transducer or the magnetic drive assembly.

18. The scanning device of claim 17, wherein the physical characteristic is a physical alteration in the magnetic drive assembly performance resulting from scanning the ultrasound transducer.

19. The scanning device of claim 17, wherein the physical characteristic is a coordinate of the ultrasound transducer or the magnetic drive assembly.

20. The scanning device of claim 17, wherein the physical characteristic is a force generated by the ultrasound transducer or the magnetic drive assembly, a velocity of the scanning of the ultrasound transducer, or an acceleration of the scanning of the ultrasound transducer.

21. The scanning device of claim 1, wherein the sensor of the magnetic drive assembly controller determines position by sensing an electrical signal characteristic of the ultrasound transducer or the magnetic drive assembly.

22. The scanning device of claim 21, wherein the electrical signal characteristic is a drive current supplied to the magnetic drive assembly, a drive voltage supplied to the magnetic drive assembly, a voltage differential signal for the magnetic drive assembly, signal strength required to the ultrasound transducer during scanning, and/or optical encoder information.

23. The scanning device of claim 1, wherein the magnetic drive controller employs a rule-based control scheme.

24. The scanning device of claim 1, wherein the magnetic drive controller employs a velocity control scheme.

25. The scanning device of claim 1, wherein the magnetic drive controller employs a positioning control scheme.

26. The scanning device of claim 1, wherein the magnetic drive controller employs a frame rate control scheme.

27. The scanning device of claim 1, wherein the magnetic drive controller employs a proportional-integral-derivative feedback control scheme, a pole placement control scheme, a sliding mode control scheme, an adaptive control through recursive least squares parameter estimation scheme, a Luenberger observer scheme, a Kalman filter scheme, an extended Kalman filter scheme, and/or an unscented Kalman filter scheme

28. The scanning device of claim 1, wherein the magnetic drive controller includes a feedback control for ultrasound transducer head positioning.

29. The scanning device of claim 28, wherein the feedback control comprises a sample and hold controller for compensating against operator movement of the scanning device during operation.

30. The scanning device of claim 29, wherein the sample and hold controller compensates against operator movement using an edge integrity algorithm.

31. The scanning device of claim 29, wherein the sample and hold controller provides real-time self registration of the two-dimensional scan data.

32. The scanning device of claim 1, wherein the applied control is rule-based.

33. An ultrasound scanning system comprising:

an ultrasound scanning device comprising (i) an ultrasound transducer to generate an ultrasound scan signal, (ii) a controller for controlling scanning of the ultrasound transducer, and (iii) a wireless transceiver for transmitting the ultrasound scan signal over a wireless communication network to a remote imaging processing system; and

a display and receiver assembly for receiving, from the remote imaging processing system, an ultrasound image data determined from the ultrasound scan signal sent to the remote imaging processing system and for displaying the ultrasound image data on the display in real-time.

34. The ultrasound scanning system of claim 33, wherein the ultrasound scanning device streams ultrasound scan signals, in real-time, to the remote imaging processing system.

35. The ultrasound scanning system of claim 33, wherein the display and receiver assembly are integrated with the ultrasound scanning device.

36. The ultrasound scanning system of claim 33, wherein the display and receiver assembly are coupled to the ultrasound scanning device through wired or wireless communication link.

37. The ultrasound scanning system of claim 33, wherein the display and receiver assembly are not communicatively coupled with the ultrasound scanning device.

38. The ultrasound scanning system of claim 33, wherein the ultrasound scan signals are raw RF signals, demodulated signals, or phase shifted signal.

39. The ultrasound scanning system of claim 33, wherein remote imaging processing system is a central server communicatively coupled to the wireless communication network.

40. The ultrasound scanning system of claim 33, wherein remote imaging processing system is a network of at least two servers coupled to each other and at least one communicatively coupled to the wireless communication network.

41. The ultrasound scanning system of claim 33, wherein the ultrasound image data is B mode image data, continuous wave (CW) Doppler image data, or pulse wave (PW) Doppler image data.

42. The ultrasound scanning system of claim 33, wherein the ultrasound image data is two-dimensional image data, three-dimensional image data, or four dimensional image data.

43. The ultrasound scanning system of claim 33, wherein the remote imaging processing system streams the ultrasound image data to the display and receiver assembly in real-time.

44. The ultrasound scanning system of claim 33, wherein the ultrasound scanning device is a handheld device.

45. The ultrasound scanning system of claim 33, wherein the remote imaging processing system processes the received ultrasound scan data into the ultrasound image data by performing one or more of an edge detection, a decorrelation, a shear movement compensation/adjustment, a wall shear velocity determination, a wall shear rate determination, a high resolution motion tracking, a high resolution strain determination, a strain rate determination, and an accumulated strain determination.