ULTRASOUND GENERATION
First Claim
1. An ultrasound generator comprising:
- a signal generator arranged to receive, generate or calculate when instructed a modulating signal with a magnitude that varies within a first range and to generate a pulsed drive signal having a predefined first relationship to the modulating signal, the pulsed drive signal having at least a zero output level, a positive output level and a negative output level, wherein the position and width of pulses are defined by at least first and second switching angles per half cycle of the modulating signal; and
a transducer arranged to generate ultrasound in response to the pulsed drive signal;
wherein the first relationship is selected such that within at least part of the range of magnitude of the modulating signal the first and second switching angles are adjusted simultaneously to provide for an increase or decrease in the magnitude of the fundamental frequency of the pulsed drive signal corresponding to an increase or decrease in the magnitude of the modulating signal; and
wherein the first relationship is selected such that a selected harmonic component of the generated pulsed drive signal is maintained below a first threshold; and
wherein the first relationship is selected such that throughout part of the range of magnitude of the modulating signal one switching angle increases while the other switching angle decreases simultaneously to provide for an increase or decrease in the magnitude of the fundamental frequency of the pulsed drive signal corresponding to an increase or decrease in the magnitude of the modulating signal.
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Accused Products
Abstract
An ultrasound generator having a signal generator; and to generate a pulsed drive signal from a modulating signal, the pulsed drive signal having at least a zero output level, a positive output level and a negative output level. The position and width of pulses are defined by at least first and second switching angles per half cycle of the modulating signal. In part of the range of the modulating signal one switching angle increases while the other switching angle decreases simultaneously such that the fundamental frequency of the pulsed drive signal increases or decreases with the modulating signal and such that a selected harmonic component of the generated pulsed drive signal is maintained below a first threshold. A transducer is arranged to generate ultrasound in response to the pulsed drive signal.
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Citations
13 Claims
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1. An ultrasound generator comprising:
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a signal generator arranged to receive, generate or calculate when instructed a modulating signal with a magnitude that varies within a first range and to generate a pulsed drive signal having a predefined first relationship to the modulating signal, the pulsed drive signal having at least a zero output level, a positive output level and a negative output level, wherein the position and width of pulses are defined by at least first and second switching angles per half cycle of the modulating signal; and a transducer arranged to generate ultrasound in response to the pulsed drive signal; wherein the first relationship is selected such that within at least part of the range of magnitude of the modulating signal the first and second switching angles are adjusted simultaneously to provide for an increase or decrease in the magnitude of the fundamental frequency of the pulsed drive signal corresponding to an increase or decrease in the magnitude of the modulating signal; and wherein the first relationship is selected such that a selected harmonic component of the generated pulsed drive signal is maintained below a first threshold; and wherein the first relationship is selected such that throughout part of the range of magnitude of the modulating signal one switching angle increases while the other switching angle decreases simultaneously to provide for an increase or decrease in the magnitude of the fundamental frequency of the pulsed drive signal corresponding to an increase or decrease in the magnitude of the modulating signal. - View Dependent Claims (2, 4, 5, 6, 7, 8, 9)
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3. (canceled)
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10. A method of generating ultrasound comprising:
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receiving, generating or calculating when instructed a modulating signal at a signal generator, the modulating signal having a magnitude that varies through a first range; generating, at the signal generator, a pulsed drive signal having a predefined first relationship to the modulating signal, the pulsed drive signal having at least a zero output level, a positive output level and a negative output level, wherein the position of pulses are defined by at least first and second switching angles per half cycle of the modulating signal; receiving the pulsed drive signal at a transducer; and generating, at the transducer, ultrasound in response to the pulsed drive signal; wherein the first relationship is selected such that within at least part of the range of magnitude of the modulating signal the first and second switching angles are adjusted simultaneously to provide for an increase or decrease in the magnitude of the fundamental frequency of the pulsed drive signal corresponding to an increase or decrease in the magnitude of the modulating signal; and wherein the first relationship is selected such that a selected harmonic component of the generated pulsed drive signal is maintained below a first threshold; and wherein the first relationship is selected such that throughout part of the range of magnitude of the modulating signal one switching angle increases while the other switching angle decreases simultaneously to provide for an increase or decrease in the magnitude of the fundamental frequency of the pulsed drive signal corresponding to an increase or decrease in the magnitude of the modulating signal. - View Dependent Claims (11, 12)
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13-24. -24. (canceled)
Specification