Patent ID: 7431728

Claim:
A method, comprising: determining an absolute value of a first input to a voltage controlled oscillator (VCO) that is in electrical communication with an acoustic assembly of an ultrasound medical device; and if the absolute value of the first input to the VCO is in a first range, maintaining a second input to the VCO, the first range comprising zero and nonzero values; if the absolute value of the first input to the VCO is in a second range, adjusting the second input to the VCO by a first voltage; and if the absolute value of the first input to the VCO is in a third range, adjusting the second input to the VCO by a second voltage, wherein an absolute value of the second voltage is greater than an absolute value of the first voltage, and wherein a maximum value of the first range is less than a minimum value of the second range, and a maximum value of the second range is less than a minimum value of the third range.