Transmit generator for controlling a multilevel pulser of an ultrasound device, and related methods and apparatus

Abstract

Circuitry for ultrasound devices is described. A multi-level pulser is described, which can support time-domain and spatial apodization. The multi-level pulser may be controlled through a software-defined waveform generator. In response to the execution of a computer code, the waveform generator may access master segments from a memory, and generate a stream of packets directed to pulsing circuits. The stream of packets may be serialized. A plurality of decoding circuits may modulate the streams of packets to obtain spatial apodization.

1 . A method, comprising:
 generating a multi-level acoustic waveform with an ultrasound device by providing a series of data packets sequentially to a pulsing circuit coupled to an ultrasonic transducer of the ultrasound device, wherein a first data packet of the series of data packets includes data identifying a duration and a reference voltage.   
     
     
         2 . The method of  claim 1 , further comprising generating the series of data packets, encoding the series of data packets, and decoding the series of data packets prior to providing the series of data packets sequentially to the pulsing circuit. 
     
     
         3 . A method, comprising:
 generating a multi-level acoustic waveform with an ultrasound device by providing a series of data packets sequentially to a pulsing circuit coupled to an ultrasonic transducer of the ultrasound device, wherein the pulsing circuit includes a pull-up transistor and a pull-down transistor, and wherein a first data packet of the series of data packets includes data identifying conductive states of the pull-up transistor and the pull-down transistor.   
     
     
         4 . The method of  claim 3 , further comprising generating the series of data packets, encoding the series of data packets, and decoding the series of data packets prior to providing the series of data packets sequentially to the pulsing circuit. 
     
     
         5 . A method of controlling a plurality of pulsers coupled to a plurality of ultrasonic transducers, the method comprising:
 transmitting a first packet to at least one pulser of the plurality of pulsers, the first packet comprising a first value representing a first reference voltage selected from a plurality of selectable reference voltages;   providing a first control signal to represent a first duration of a first pulse segment;   in response to transmitting the first packet to the at least one pulser of the plurality of pulsers, setting the at least one pulser of the plurality of pulsers to a first state corresponding to the first reference voltage throughout the first duration of the first pulse segment;   transmitting a second packet to the at least one pulser of the plurality of pulsers, the second packet comprising a second value representing a second reference voltage selected from the plurality of selectable reference voltages;   providing a second control signal to represent a second duration of a second pulse segment;   in response to transmitting the second packet to the at least one pulser of the plurality of pulsers, setting the pulser of the plurality of pulsers to a second state corresponding to the second reference voltage throughout the second duration of the second pulse segment;   wherein the plurality of selectable reference voltages comprises at least three reference voltages.   
     
     
         6 . The method of  claim 5 , further comprising generating an acoustic ultrasound waveform segment using at least one ultrasonic transducer of the plurality of ultrasonic transducers, in response to setting the at least one pulser of the plurality of pulsers to the first state, wherein the acoustic ultrasound waveform segment has a magnitude that is determined by the first reference voltage. 
     
     
         7 . The method of  claim 5 , wherein the at least one pulser of the plurality of pulsers comprises a first transistor and a second transistor, and wherein the first packet comprises a value representing a first conductive state associated with the first transistor and a second conductive state associated with the second transistor; and
 causing the first transistor to assume the first conductive state and the second transistor to assume the second conductive state based on the value.   
     
     
         8 . The method of  claim 5 , further comprising modulating the first packet across the plurality of pulsers to obtain spatial apodization. 
     
     
         9 . The method of  claim 5 , wherein the first packet and the second packet are transmitted serially. 
     
     
         10 . The method of  claim 5 , wherein the at least one pulser of the plurality of pulsers is configured to provide a bipolar waveform to at least one ultrasonic transducer of the plurality of ultrasonic transducers. 
     
     
         11 . The method of  claim 5 , further comprising generating a plurality of time-delayed versions of the first packet; and
 providing the plurality of time-delayed versions of the first packet to the plurality of pulsers.   
     
     
         12 . A method of controlling a plurality of pulsers coupled to a plurality of ultrasonic transducers, the method comprising:
 selecting two or more waveform segments from among a plurality of waveform segments;   concatenating the selected two or more waveform segments to form an input waveform; and   providing the input waveform to a pulser of the plurality of pulsers coupled to the plurality of ultrasonic transducers;   wherein the input waveform is a first input waveform of the plurality of input waveforms and the pulser is a first pulser of the plurality of pulsers, and further comprising providing a second input waveform to a second pulser of the plurality of pulsers, wherein the first input waveform and the second input waveforms have different amplitudes.   
     
     
         13 . The method of  claim 12 , further comprising
 generating a pulse with the pulser from the input waveform;   providing the pulse to an ultrasonic transducer of the plurality of ultrasonic transducers ; and   generating an acoustic ultrasonic waveform with the ultrasonic transducer of the plurality of ultrasonic transducers based on the pulse.   
     
     
         14 . The method of  claims 12 , wherein the pulser of the plurality of pulsers is configured to provide a multi-level pulse to at least one ultrasonic transducer of the plurality of ultrasonic transducers. 
     
     
         15 . The method of  claim 12 , wherein the pulser of the plurality of pulsers is configured to provide a bipolar pulse to at least one ultrasonic transducer of the plurality of ultrasonic transducers. 
     
     
         16 . The method of  claim 12 , further comprising selecting a voltage reference from among a plurality of voltage references; and
 selecting the two or more waveform segments from among the plurality of waveform segments based on the selected voltage reference.   
     
     
         17 . The method of  claim 12 , wherein the plurality of ultrasonic transducers comprise at least one capacitive ultrasonic transducer. 
     
     
         18 . The method of  claim 12 , wherein providing the input waveform to the pulser of the plurality of pulsers coupled to the plurality of ultrasonic transducers comprises transmitting the input waveform at least in part serially.