Element mapping and transmitter for continuous wave ultrasound imaging

• US 20050203391A1
• Filed: 02/26/2004
• Published: 09/15/2005
• Est. Priority Date: 02/26/2004
• Status: Active Grant

• Current Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Original Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Inventors: Petersen, David A., Phelps, Robert N.
• Granted Patent: US 7,794,400 B2
• Time in Patent Office: Days
• US Class Current: 600/437
• 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 8/4488 the transducer being a phased array
• CPC Class Codes: G01S 15/8927 using simultaneously or sequentially two or more subarrays or subapertures
• CPC Class Codes: G01S 7/52019 Details of transmitters
• CPC Class Codes: G01S 7/5208 with integration of processing functions inside probe or scanhead

Abstract

Element mapping and transmission of continuous waves are provided ultrasound imaging. For use with multiple dimensional or large arrays, the number of receive beamformer channels or associated cables connecting the transducer array to the receive beamformer may be limited. Subarrays of signals from different elements associated with similar phasing are combined without switching. The combined subarray signals are then received beamformed to generate a continuous wave image. Receive channels without clocking or beamforming prior to a steered continuous wave Doppler beamformer maximize dynamic range and reduce the power consumption. For further or different optimization of steering continuous waves, low voltage transmitters separate from high voltage transmitters are provided for a plurality of elements.

Claims

1. A system for selecting subarrays in continuous wave ultrasound imaging, the system comprising:

a transducer array as part of a transducer assembly, the transducer array having a plurality of elements; and

a plurality of combiners as part of the transducer assembly, each of the combiners operable to combine signals from a respective plurality of elements corresponding to a subarray;

wherein channels from the plurality of elements to the plurality of combiners are operable to be free of switching during reception of continuous wave signals.

2. The system of claim 1 wherein the transducer array comprises a multi-dimensional array.

3. The system of claim 1 wherein the transducer assembly comprises a transducer probe housing, both the transducer array and the plurality of combiners at least partially within the transducer probe housing.

4. The system of claim 1 further comprising:

a plurality of switches within the channels, the switches operable to select between connection of each of the elements to different ones of the plurality of combiners, the selection corresponding to the subarrays, the switches operable to select prior to combination of the continuous wave signals and operable to remain static during combination of the continuous wave signals.

5. The system of claim 1 further comprising:

a plurality of switches operable to define the subarrays, each of the subarrays corresponding to elements of the plurality of elements having a similar phase shift.

6. The system of claim 1 wherein the subarrays correspond to elements of the plurality of elements having a similar phase shift.

7. The system of claim 1 wherein the subarrays correspond to elements of the plurality of elements with similar phase shifts and with phase shifts about 180 degrees from the similar phase shifts.

8. The system of claim 7 further comprising:

a plurality of inverters operable to invert the continuous wave signals of the elements with the phase shifts about 180 degrees from the similar phase shifts.

9. The system of claim 1 further comprising:

a plurality of amplifiers operable to apply different amounts of amplification for continuous wave signals associated with different subarrays, the plurality of amplifiers being part of the transducer assembly.

10. The system of claim 1 further comprising:

at least one switch for each of the channels and corresponding elements of the plurality of element, the switch operable to remain static for receiving continuous wave signals from the respective element and operable to perform one of;

mixing and multiplexing for pulsed wave signals from the respective element.

11. The system of claim 1 further comprising:

a high-voltage transmitter connected with the plurality of elements; and

a low voltage transmitter as part of the transducer assembly connected with the plurality of elements.

12. A method for selecting subarrays in continuous wave ultrasound imaging, the method comprising:

(a) summing continuous wave signals from a first plurality of elements of an array corresponding to a first range of phase shifts;

(b) summing continuous wave signals from a second plurality of elements of the array corresponding to a second range of phase shifts different than the first range; and

(c) transmitting the outputs of (a) and (b) separately to a receive beamformer.

13. The method of claim 12 further comprising:

(d) maintaining the continuous wave signals free of switching from the first and second pluralities of elements through summation.

14. The method of claim 12 wherein (a) and (b) are performed within a transducer probe and the receive beamformer comprises a continuous wave beamformer in an imaging system spaced from the transducer probe by a cable.

15. The method of claim 12 further comprising:

(d) selecting the first plurality of elements as a function of a steering angle; and

(e) selecting the second plurality of elements as a function of the steering angle.

16. The method of claim 12 wherein (a) comprises summing continuous wave signals of the first range of phase shifts with inverted continuous wave signals having phase shifts about 180 degrees from the first range of phase shifts.

17. The method of claim 12 wherein (a) and (b) comprises forming subarray signals for first and second subarrays, respectively, of a multi-dimensional transducer array.

18. The method of claim 12 wherein a different number of the continuous wave signals are summed in (a) than in (b);

further comprising;

(d) amplifying associated with (a) differently than with (b) as a function of the different number.

19. The method of claim 12 wherein at least one switch is positioned after each of the elements of the first and second pluralities of elements and prior to a combiner performing the summations of (a) and (b), each switch having an open and a closed state;

further comprising;

(d) maintaining each switch at the closed state or open state during reception of the continuous wave signals in response to a first continuous transmit event; and

(e) moving the switches between the open and closed states during reception of pulsed wave signals in response to a second pulsed transmit event.

20. The method of claim 12 further comprising:

(d) generating continuous wave transmit waveforms with a first transmitter in a transducer probe, (a) and (b) being performed in the transducer probe;

(e) generating pulsed wave transmit waveforms with a second transmitter.

21. A system for transmission of continuous waves in ultrasound imaging, the system comprising:

a transducer array;

a pulsed wave transmitter connectable with the transducer array;

a continuous wave transmitter connectable with the transducer array, the continuous wave transmitter separate from the pulsed wave transmitter.

22. The system of claim 21 further comprising:

a probe housing, the transducer array and the continuous wave transmitter within the probe housing.

23. The system of claim 22 wherein the pulsed wave transmitter is within the probe housing.

24. The system of claim 21 wherein the transducer array comprises at least one transducer element having first and second sides, the pulsed wave transmitter connectable with the first side and the continuous wave transmitter connectable with the second side.

25. The system of claim 24 further comprising:

a receiver pre-amplifier connected with the second side.

26. The system of claim 24 wherein the pulsed wave transmitter comprises first and second transistors, the first transistor connected between the first side and a high power voltage source, the second transistor connected between the first side and a relative ground potential;

and wherein the continuous wave transmitter comprises third and fourth transistors, the third transistor connected between the second side and a low power voltage source, the fourth transistor connected between the second side and the relative ground potential.

27. A method for transmission of continuous waves in ultrasound imaging, the method comprising:

(a) generating continuous waves with a continuous wave transmitter separate from a pulsed wave transmitter;

(b) applying the continuous waves to a transducer array within a same probe housing as the continuous wave transmitter.

28. The method of claim 27 further comprising:

(c) connecting the continuous wave transmitter to a first side of an element; and

(d) connecting the pulsed wave transmitter to a second side of the element.

29. The method of claim 28 further comprising:

(e) connecting a receive channel to the first side of the element.