Ultrasound imaging system

• US 6,638,226 B2
• Filed: 09/28/2001
• Issued: 10/28/2003
• Est. Priority Date: 09/28/2001
• Status: Active Grant

• Current Assignee: Teratech Corporation
• Original Assignee: Teratech Corporation
• Inventors: He, Xingbai, Chang, Peter P., Chiang, Alice M., Kischell, Eric R.
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): Jain, Ruby
• Application Number:
  US09/966,810
• Publication Number:
  US 20030088182A1
• Time in Patent Office: 760 Days
• Field of Search: 600/453-456, 600/441, 600/447, 342/179, 378/4
• US Class Current: 600/443
• CPC Class Codes: A61B 8/065 to determine blood output from the heart in general A61B5/029
• CPC Class Codes: A61B 8/4427 Device being portable or laptop-like
• CPC Class Codes: A61B 8/463 characterised by displaying multiple images or images and diagnostic data on one display composite display in devices for short-range imaging with acoustic waves G01S7/52074
• CPC Class Codes: A61B 8/486 involving arbitrary m-mode
• CPC Class Codes: A61B 8/488 involving Doppler signals
• CPC Class Codes: A61B 8/5223 for extracting a diagnostic or physiological parameter from medical diagnostic data for algorithms to analyse biomedical images G06T7/0012
• CPC Class Codes: A61B 8/54 Control of the diagnostic device
• CPC Class Codes: A61B 8/56 Details of data transmission or power supply
• CPC Class Codes: G01S 15/584 with measures taken for suppressing velocity ambiguities, i.e. anti-aliasing
• CPC Class Codes: G01S 15/8979 Combined Doppler and pulse-echo imaging systems
• 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 7/003 Transmission of data between radar, sonar or lidar systems and remote stations
• CPC Class Codes: G01S 7/52044 Scan converters
• CPC Class Codes: G01S 7/52063 Sector scan display
• CPC Class Codes: G01S 7/52071 Multicolour displays; using colour coding; Optimising colour or information content in displays, e.g. parametric imaging
• CPC Class Codes: G01S 7/5208 with integration of processing functions inside probe or scanhead
• CPC Class Codes: G01S 7/52082 involving a modular construction, e.g. a computer with short range imaging equipment modular ultrasonic medical diagnostic devices A61B8/4411
• CPC Class Codes: G01S 7/52084 related to particular user interfaces special user input means for ultrasonic medical diagnostic devices A61B8/467

Abstract

The present invention is directed to an ultrasound imaging system and method for Doppler processing of data. The ultrasonic imaging system efficiently addresses the data computational and processing needs of Doppler processing. Software executable sequences in accordance with a preferred embodiment of the present invention determines the phase shift and the auto-correlation phase of filtered image data. In a preferred embodiment, the system of ultrasonic imaging also includes a sequence of instructions for Doppler processing that provides the functions for demodulation, Gauss Match filtering, auto-correlation calculation, phase shift calculation, frame averaging, and scan conversion implemented with Single Instruction Multiple Data (SIMD) or Multiple Instruction Multiple Data (MIMD) instructions. In a preferred embodiment, the ultrasound imaging system of the present invention includes a processing module; and memory operable coupled to the processing module, wherein the memory stores operational instructions that cause the processing module to map serial data to vector representation, calculate an auto-correlation function of the data, calculate a phase shift of the auto-correlation function to generate a monotonic function covering all values of the phase shift corresponding to a range of Doppler velocities and display the resultant images, for example, as color images.

Claims

1. A portable ultrasound system for scanning a region of interest with ultrasound energy to image a fluid moving within the region of interest comprising.

a hand held probe having a transducer array mounted therein;

a front-end interface unit having a beamforming device and a transceiver chip, the front-end interface unit being connected to the handheld probe and to a data processing system;

a Doppler processing system disposed in the data processing system, having at least one parallel computing element, and a memory coupled to the at least one parallel computing element, the memory having stored therein a sequence of instructions to execute Doppler processing by demodulating data collected from the region of interest to obtain in-phase and quadrature data, averaging a plurality of frames of data, and converting phase shift data to an index.

2. The portable ultrasound system of claim 1, wherein the at least one parallel computing element is a multiplier and an adder.

3. The portable ultrasound system of claim 1, wherein the at least one parallel computing element executes at least one of Single Instruction Multiple Data instructions and Multiple Instruction Multiple Data instructions.

4. The portable ultrasound system of claim 1, wherein Doppler processing is executed in a computation device such as a Pentium®

III having a MMX™

processor.

5. In an ultrasound system based on Doppler processing, a method for imaging a region of interest comprising of:

providing a handheld probe and an associated processing system for capturing images of an area of interest; and

providing a data processing system coupled to the associated processing system having a microprocessor with at least one parallel processing element and a memory coupled to the microprocessor having stored therein a sequence of instructions to execute Doppler processing wherein the instructions comprise;

demodulating the data to obtain in-phase and quadrature sample data;

filtering the data to remove low frequency signals;

averaging a plurality of frames of data;

converting phase shift data to an index;

converting the phase shift data from scan to raster coordinates; and

displaying a plurality of images.

6. A computer readable medium having stored therein instructions for causing a processing unit to execute the steps of the method of claim 5.

7. The method for imaging a region of interest of claim 5, wherein the sequence of instructions comprises of:

mapping a stream of serial data to a vector representation;

calculating an auto-correlation function of the data; and

calculating a phase shift of the auto-correlation function to generate a monotonic function for all values of the phase shift corresponding to a range of Doppler velocities.

8. The method for imaging a region of interest of claim 5, wherein at least one parallel processing element is a multiplier and an adder.

9. The method for imaging a region of interest of claim 5, wherein at least one parallel processing element executes at least one of Single Instruction Multiple Data instructions and Multiple Instruction Multiple Data instructions.

10. A method of imaging a region of interest with ultrasound energy comprising of:

providing a portable ultrasound imaging system including a transducer array within a handheld probe, an interface unit connected to the handheld probe with a first cable interface, the interface unit having a beamforming device and being connected to a data processing system with a second cable interface;

providing output signals from the interface unit to the handheld probe to actuate the transducer array;

delivering ultrasound energy to the region of interest;

collecting ultrasound energy returning to the transducer array from the region of interest;

transmitting data from the handheld probe to the interface unit with the first cable interface;

performing a beamforming operation with the beamforming device in the interface unit; and

transmitting data from the interface unit to the data processing system with the second cable interface such that the data processing system receives a beamformed electronic representation of the region of interest;

the data processing system having at least one parallel processing element integrated therein to execute a sequence of instructions for processing and displaying Doppler images, a particular sequence of instruction comprising calculating a phase shift of an auto-correlation function to generate a monotonic function for all values of the phase shift corresponding to a range of Doppler velocities wherein the instructions comprise demodulating the data to obtain in-phase and quadrature sample data, filtering the data to remove low frequency signals, averaging a plurality of frames of data, converting phase shift data to an index, converting the phase shift data from scan to raster coordinates and displaying a plurality of images.

11. A computer readable medium having stored therein instructions for causing the processing system to execute the steps of method of claim 10.

12. The method of imaging a region of interest of claim 10, wherein at least one parallel processing element is a multiplier and an adder.

13. The method of imaging a region of interest of claim 10, wherein at least one parallel processing element executes at least one of Single Instruction Multiple Data instructions and Multiple Instruction Multiple Data instructions.

14. An ultrasound imaging apparatus comprising:

at least one processing module; and

memory operable coupled to the at least one processing module, wherein the memory stores operational instructions that cause the at least one processing module to;

map serial data to vector representation;

calculate an auto-correlation function of the data;

calculate a phase shift of the auto-correlation function to generate a monotonic function for all values of the phase shift corresponding to a range of Doppler velocities;

demodulate the data to obtain in-phase and quadrature data;

filter the data to remove low frequency signals;

average a plurality of frames of data;

convert the phase shift to an index; and

display a plurality of images.

15. The apparatus of claim 14, wherein the apparatus further comprises a handheld probe operable to transmit an ultrasound image and to obtain data indicative of the flow characteristics of the region of interest.

16. A portable ultrasound system for imaging a region of interest comprising:

an ultrasound probe system including a transducer array and a beamforming device; and

a data processing system connected to the ultrasound probe system with a standard high-speed transmission link such that the data processing system receives a beamformed representation of the region of interest;

the data processing system having a microprocessor coupled to at least one parallel processing element for Doppler processing computations wherein a memory stores a sequence of instructions for demodulating the data to obtain in-phase and quadrature sample data, filtering the data to remove low frequency signals, averaging a plurality of frames of data, converting phase shift data to an index, converting the phase shift data from scan to raster coordinates, and displaying a plurality of images.

17. The system of claim 16, wherein the ultrasound probe system further comprises a beamforming circuit having a programmable delay device.

18. The system of claim 16, further comprising an interface unit connected to a probe housing and a circuit board within the interface unit, the circuit board having a beamforming integrated circuit mounted thereon.

19. The system of claim 18, further comprising a display and a battery in the data processing system such that the battery provides power to the probe housing.

20. The system of claim 18, further comprising a digital signal processor in the interface unit.

21. The system of claim 18, further comprising a data transmitter that forwards isochronous data from the probe system to the data processing unit.

22. The system claim of 16, wherein the at least one parallel processing element is a multiplier and an adder.

23. The system of claim 16, wherein the at least one parallel processing element executes at least one of Single Instruction Multiple Data instructions and Multiple Instruction Multiple Data instructions.

24. The system of claim 18, wherein the interface unit comprises a wireless interface.

25. The system of claim 16, wherein the probe system comprises a handheld housing having a transducer array and an interface unit.

26. The system of claim 18, wherein asynchronous signals are transmitted from the data processing system to the probe.

27. A portable ultrasound system for scanning a region of interest with ultrasound energy to image a fluid moving within the region of interest comprising.

a hand held probe having a transducer array mounted therein;

a front-end interface unit having a beamforming device and a transceiver chip, the beamforming device comprising a single integrated circuit, the front-end interface unit being connected to the handheld probe and to a data processing system;

a Doppler processing system disposed in the data processing system, having at least one parallel computing element, and a memory coupled to the at least one parallel computing element, the memory having stored therein a sequence of instructions to execute Doppler processing by demodulating data collected from the region of interest to obtain in-phase and quadrature data, and further processing phase shift data.

28. The portable ultrasound system of claim 27, wherein the at least one parallel computing element is a multiplier and an adder.

29. The portable ultrasound system of claim 27, wherein the at least one parallel computing element executes at least one of Single Instruction Multiple Data instructions and Multiple Instruction Multiple Data instructions.

30. The portable ultrasound system of claim 27, wherein Doppler processing is executed in a computation device such as a Pentium®

III having a MMX™

processor.

31. The portable ultrasound system of claim 27, wherein further processing phase shift data comprises filtering the data, frame averaging and scan conversion.