Ultrasound scan conversion with spatial dithering

• US 6,248,073 B1
• Filed: 12/02/1998
• Issued: 06/19/2001
• Est. Priority Date: 06/29/1995
• Status: Expired due to Term

• Current Assignee: Teratech Corporation
• Original Assignee: Teratech Corporation
• Inventors: Chiang, Alice M., Gilbert, Jeffrey M., Broadstone, Steven R.
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): PATEL, MAULIN M
• Application Number:
  US09/203,877
• Time in Patent Office: 930 Days
• Field of Search: 600/443, 600/444, 600/447, 600/448, 600/449, 600/437, 600/459, 128/916
• US Class Current: 600/447
• CPC Class Codes: A61B 2560/045 with a separable interface unit, e.g. for communication
• CPC Class Codes: A61B 7/04 Electric stethoscopes microphones, acoustic transducers therefor H04R
• CPC Class Codes: A61B 8/00 Diagnosis using ultrasonic, sonic or infrasonic waves imaging of objects using sonar G01S15/00
• 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 8/4455 Features of the external shape of the probe, e.g. ergonomic aspects
• CPC Class Codes: A61B 8/4488 the transducer being a phased array
• 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 8/465 adapted to display user selection data, e.g. icons or menus
• CPC Class Codes: A61B 8/56 Details of data transmission or power supply
• CPC Class Codes: G01S 15/8915 using a transducer array
• CPC Class Codes: G01S 15/8934 using a dynamic transducer configuration
• CPC Class Codes: G01S 15/8979 Combined Doppler and pulse-echo imaging systems
• CPC Class Codes: G01S 15/899 Combination of imaging systems with ancillary equipment
• CPC Class Codes: G01S 7/003 Transmission of data between radar, sonar or lidar systems and remote stations
• CPC Class Codes: G01S 7/52023 Details of receivers
• CPC Class Codes: G01S 7/52025 for pulse systems G01S7/52034 takes precedence
• CPC Class Codes: G01S 7/52026 Extracting wanted echo signals Doppler systems G01S15/50; Doppler short range imaging systems G01S15/8979
• CPC Class Codes: G01S 7/52034 Data rate converters
• CPC Class Codes: G01S 7/52044 Scan converters
• CPC Class Codes: G01S 7/52046 Techniques for image enhancement involving transmitter or receiver image enhancement by image data processing G06T5/00
• CPC Class Codes: G01S 7/52053 : Display arrangements
• CPC Class Codes: G01S 7/52063 : Sector scan display
• CPC Class Codes: G01S 7/52073 : Production of cursor lines, markers or indicia by electronic means
• CPC Class Codes: G01S 7/52074 : Composite displays, e.g. split-screen displays; Combination of multiple images or of images and alphanumeric tabular information
• CPC Class Codes: G01S 7/52079 : Constructional features constructional features of transducers B06B; mounting transducers G10K11/00; constructional features of ultrasonic medical diagnostic devices A61B8/44
• CPC Class Codes: G01S 7/5208 : with integration of processing functions inside probe or scanhead

Abstract

An ultrasound imaging system includes a scan conversion process for converting ultrasound data into a standard display format conversion and can be performed on a personal computer by programming the computer to convert data from polar coordinates to cartesian coordinates suitable for display on a computer monitor. The data is provided from scan head enclosure that houses an array of ultrasonic transducers and the circuitry associated therewith, including pulse synchronizer circuitry used in the transmit mode for transmission of ultrasonic pulses and beam forming circuitry used in the receive mode to dynamically focus reflected ultrasonic signals returning from the region of interest being imaged.

Claims

1. A method of forming ultrasound image data comprising:

receiving ultrasound signals with a transducer array in a hand held housing to form an electronic representation of the ultrasound signals;

beamforming the electronic representation with a beamformer device within the handheld housing to provide beamformed data;

transmitting the beamformed data along a flexible cable from the handheld housing to a data processor housing; and

converting the input data into output image data with a scan converter in the data processor housing.

2. The method of claim 1 comprising the steps of:

providing an input array of input data; and

spatially dithering the input data to convert the input data into an output array of output data.

3. The method of claim 2 wherein the step of spatial dithering comprises rounding position data from arbitrary precision values to integer values with remainder values.

4. The method of claim 3 wherein the step of spatial dithering further comprises propagating remainder values through the output data.

5. The method of claim 2 wherein the step of spatial dithering comprises:

calculating a first position in the output array from a first value in the input array; and

using the first position, calculating a second position in the output array.

6. The method of claim 5 wherein the first and second positions represent adjacent display pixel locations.

7. The method of claim 2 wherein the step of spatial dithering is performed in a general purpose computer.

8. The method of claim 7 wherein the general purpose computer is a portable computer.

9. The method of claim 2 wherein the step of providing an input array further comprises receiving the input data from the ultrasonic device in polar coordinates.

10. The method of claim 2 further comprising mapping the output array to the input array.

11. The method of claim 10 wherein the step of mapping comprises initializing a remap array based on changes to the display format.

12. The method of claim 1 further comprising providing a scan conversion circuit that spatially dithers the input data.

13. The method of claim 1 further comprising converting a plurality of frames of input data at a rate of at least 20 frames per second.

14. The method of claim 13 further comprising converting at a rate of about 30 frames per second or more.

15. An ultrasound imaging system comprising:

a transducer array mounted on a handheld probe that transmits and receives ultrasound signals;

a beamforming circuit electrically connected to the transducer array within the handheld probe and that forms an electronic representation of an object to be imaged;

a programmable data processing system that receives the electronic representation, the data processing system being programmed to perform scan conversion of the electronic representation to a display format; and

a flexible cable that connects the handheld probe to the data processing system.

16. The system of claim 15 wherein the programmable data processing system is a personal computer.

17. The system of claim 15 wherein the programmable data processing system is a portable computer having a keyboard and a liquid crystal display.

18. The system of claim 15 wherein the programmable data processing system is a palmtop computer.

19. The system of claim 15 further comprising an interface circuit that connects the cable to the data processing system.

20. The system of claim 15 wherein the data processing system further comprises a firewire standard connection to the flexible cable.

21. The system of claim 15 further comprising an analog to digital converter in the handheld probe such that a digital signal is conducted along the flexible cable.

22. The system of claim 15 wherein the data processing system further comprises a scan conversion circuit.

23. The system of claim 15 wherein the handheld probe further comprises a housing having a transducer array at one end and a cable connector at an opposite end, the housing enclosing a system controller electrically connected to the beamformer circuit and a memory circuit connected to the system controller.

24. The system of claim 15 further comprising a sampling circuit connected to the beamformer circuit.

25. The system of claim 15 wherein further comprises a memory having a remap array that converts an input array to an output array.

26. The system of claim 23 wherein the handheld probe housing further comprises a transmit/receive circuit connected to the transducer array.

27. The system of claim 15 further comprising a display connected to the data processing system.

28. The system of claim 15 wherein the data processing system includes a battery.

29. An ultrasound imaging system comprising:

a transducer array mounted on a handheld probe that transmits and receives ultrasound signals;

a beamforming circuit electrically connected to the transducer array within the handheld probe and that forms an electronic representation of an object to be imaged;

a data processing system that receives the electronic representation, the data processing system performing scan conversion of the electronic representation to a display format;

a display connected to the data processing system;

a battery within a housing for the data processing system, the battery providing power to the data processing system and the display; and

a flexible cable that connects the handheld probe to the data processing system.

30. The system of claim 29 wherein the data processing system is a personal computer.

31. The system of claim 29 wherein the data processing system is a portable computer having a keyboard and a liquid crystal display.

32. The system of claim 29 wherein the programmable data processing system is a palmtop computer.

33. The system of claim 29 further comprising an interface circuit that connects the cable to the data processing system.

34. The system of claim 29 wherein the data processing system further comprises a firewire standard connection to the flexible cable.

35. The system of claim 29 further comprising an analog to digital converter in the handheld probe such that a digital signal is conducted along the flexible cable.

36. The system of claim 29 wherein the data processing systemfurther comprises a scan conversion circuit.

37. The system of claim 29 wherein the handheld probe further comprises a housing having a transducer array at one end and a cable connector at an opposite end, the housing enclosing a system controller electrically connected to the beamformer circuit and a memory circuit connected to the system controller.

38. The system of claim 29 further comprising a sampling circuit connected to the beamformer circuit.

39. The system of claim 29 wherein further comprises a memory having a remap array that converts an input array to an output array.

40. The system of claim 37 wherein the handheld probe housing further comprises a transmit/receive circuit connected to the transducer array.