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US 10,016,209 B2Granted
System and method for driving an ultrasonic handpiece as a function of the mechanical impedance of the handpiece
AssigneeStryker Corporation
InventorsAdam Downey, Matthew Owen
Life of this patent
Estimating the term…
Abstract
An ultrasonic surgical tool system for actuating a handpiece with a tip. The voltage and frequency of the drive signal applied to the handpiece drivers is a function of the equivalent of current through the mechanical components of the handpiece and tip and the frequency responsiveness of these components.
Claims23
A system for vibrating the tip of an ultrasonic handpiece, the handpiece having at least one driver to which an AC drive signal is applied to vibrate the tip, the system including:
- an assembly for generating a variable AC drive signal that is applied to the handpiece having at least one driver;
- an assembly for measuring the voltage of the AC drive signal that outputs a signal representative of drive signal voltage;
- an assembly for measuring the current of the AC drive signal that outputs a signal representative of drive signal current;
- and
- a processor that is configured to receive the signal representative of drive signal voltage and the signal representative of drive signal current and that, based on the signal representative of drive signal voltage and the signal representative of drive signal current, is configured to regulate the assembly that generates the AC drive signal to establish the characteristics of the AC drive signal wherein, said processor is configured to:
- determine a target current, the target current being the equivalent of current to be applied to the mechanical components of the handpiece;
- based on the signal representative of drive signal voltage, the signal representative of drive signal current, a frequency of the AC drive signal and the capacitance of the at least one driver, calculating an equivalent of current applied to mechanical components of the handpiece;
- compare the target current to the calculated equivalent of current applied to the mechanical components of the handpiece;
- based on said current comparison, set the potential of the AC drive signal output by the assembly that generates the drive signal;
- based on the signal representative of drive signal voltage, the signal representative of drive signal current, the frequency of the AC drive signal and the capacitance of the piezoelectric driver, calculate a ratio between current applied to the at least one driver and the equivalent of current applied to the mechanical components of the handpiece;
- and
- based on the calculated ratio, set the frequency of the AC drive signal output by the assembly that generates the AC drive signal.
9 more elements
A method of regulating the sourcing of a drive signal to an ultrasonic handpiece that is applied to tissue to perform a medical or surgical procedure, said method including the steps of:
- determining the capacitance of a driver in an ultrasonic handpiece having at least one driver and a tip that is attached to said driver for vibration by the driver, wherein;
- determining a target current, the target current being an equivalent of current applied to the mechanical components of the handpiece, wherein, components of the handpiece other than the driver are the mechanical components of the handpiece;
- sourcing an AC drive signal to the driver, the drive signal having a potential and a frequency;
- measuring a voltage and a current of the drive signal;
- based on the voltage of the drive signal, the current of the drive signal, the frequency of the drive signal and the capacitance of the driver, calculating the equivalent of current applied to the mechanical components of the handpiece;
- comparing the target current to the calculated equivalent of current applied to the mechanical components of the handpiece;
- based on said current comparison, adjusting the potential of the drive signal;
- and
- based on the voltage of the drive signal, the current of the drive signal, the frequency of the drive signal and the capacitance of the piezoelectric driver, calculating a ratio between current applied to the driver and the equivalent of the equivalent of current applied to the mechanical components of the handpiece;
- and
- based on the calculated ratio, adjusting the frequency of the drive signal.
8 more elements
A system for vibrating the tip of an ultrasonic handpiece, the handpiece having at least one driver to which an AC drive signal is applied to vibrate the tip, the system including:
- an assembly for generating a variable AC drive signal that is applied to the handpiece having at least one driver;
- an assembly for measuring the voltage of the AC drive signal that outputs a signal representative of drive signal voltage;
- an assembly for measuring the current of the of the AC drive signal that outputs a signal representative of drive signal current;
- and
- a processor that is configured to receive the signal representative of drive signal voltage and the signal representative of drive signal current and, based on the signal representative of drive signal voltage and the signal representative of drive signal current, that is configured to regulate the assembly for generating the AC drive signal to establish the characteristics of the AC drive signal wherein, said processor is configured to:
- determine a target current, the target current being the equivalent of current applied to the mechanical components of the handpiece;
- based on the signal representative of drive signal voltage, the signal representative of drive signal current, the frequency of the AC drive signal and the capacitance of the at least one driver, calculate the equivalent of current applied to mechanical components of the handpiece;
- based on the signal representative of drive signal voltage, the signal representative of drive signal current, the frequency of the AC drive signal and the capacitance of the driver, calculate a ratio between current applied to the driver and the equivalent of current applied to the mechanical components of the handpiece;
- compare the ratio between current applied to the driver and the equivalent of current applied to the mechanical components of the handpiece to a target ratio;
- as a result of the comparison of the ratio between current applied to the driver and the equivalent of current applied to the mechanical components of the handpiece to the target ratio, selectively setting the frequency of the AC drive signal;
- compare the target current to the calculated equivalent of current applied to the mechanical components of the handpiece;
- and
- based on said current comparison, adjust the target ratio for the next comparison of the ratio between current applied to the driver and the equivalent of current applied to the mechanical components of the handpiece to the target ratio.
10 more elements
A method of regulating the sourcing of a drive signal to an ultrasonic handpiece that is applied to tissue to perform a medical or surgical procedure, said method including the steps of:
- determining the capacitance of a driver in an ultrasonic handpiece having at least one driver and a tip that is attached to said driver for vibration by the driver, wherein;
- determining a target current, the target current being an equivalent of current applied to the mechanical components of the handpiece, wherein, components of the handpiece other than the driver are the mechanical components of the handpiece;
- sourcing an AC drive signal to the driver, the drive signal having a potential and a frequency;
- measuring the voltage and current of the drive signal;
- based on the voltage of the drive signal, the current of the drive signal, the frequency of the drive signal and the capacitance of the driver, calculating the equivalent of current applied to the mechanical components of the handpiece;
- comparing the target current to the calculated equivalent of current applied to the mechanical components of the handpiece;
- based on said current comparison, adjusting the potential of the drive signal;
- and
- based on the voltage of the drive signal, the current of the drive signal, the frequency of the drive signal and the capacitance of the piezoelectric driver, calculating a ratio between current applied to the driver and the equivalent of the equivalent of current applied to the mechanical components of the handpiece;
- and
- based on the calculated ratio, adjusting the frequency of the drive signal, comparing the target current to the calculated equivalent of current applied to the mechanical components of the handpiece;
- and
- based on said current comparison, adjusting the target ratio for the next comparison of the ratio between current applied to the driver and the equivalent of current applied to the mechanical components of the handpiece to the target ratio.
10 more elements
Dependencies are inferred from the claim text.