Estimating state of ultrasonic end effector and control system therefor

Patent metadata

Field	Value
Publication number	US-12042207-B2
Application number	US-202217962901-A
Country	US
Kind code	B2
Filing date	Oct 10, 2022
Priority date	Dec 28, 2017
Publication date	Jul 23, 2024
Grant date	Jul 23, 2024

Abstract

Various aspects of a generator, ultrasonic device, and method for estimating a state of an end effector of an ultrasonic device are disclosed. The ultrasonic device includes an electromechanical ultrasonic system defined by a predetermined resonant frequency, including an ultrasonic transducer coupled to an ultrasonic blade. A control circuit measures a complex impedance of an ultrasonic transducer, wherein the complex impedance is defined as
Z g ( t ) = V g ( t ) I g ( t ) .
The control circuit receives a complex impedance measurement data point and compares the complex impedance measurement data point to a data point in a reference complex impedance characteristic pattern. The control circuit then classifies the complex impedance measurement data point based on a result of the comparison analysis and assigns a state or condition of the end effector based on the result of the comparison analysis.

First claim

The invention claimed is:

1. A method of estimating a state of an end effector of an ultrasonic device, the ultrasonic device including an electromechanical ultrasonic system defined by a predetermined resonant frequency, the electromechanical ultrasonic system including an ultrasonic transducer coupled to an ultrasonic blade, the method comprising:
applying, by a drive circuit, a drive signal to an ultrasonic transducer, wherein the drive signal is a periodic signal defined by a magnitude and a frequency;
sweeping, by a control circuit, the frequency of the drive signal from below the predetermined resonant frequency to above the predetermined resonant frequency of the electromechanical ultrasonic system;
measuring and recording, by the control circuit, impedance circle variables R e , and X e , and admittance circle variable G e , and B e ;
comparing, by the control circuit, measured impedance circle variables R e , and X e , to reference impedance circle variables R ref , and X ref , respectively;
comparing, by the control circuit, measured admittance circle variables G e , and B e to reference admittance circle variables G ref , and B ref , respectively;
and
determining, by the control circuit, a state or condition of the end effector based on the result of the comparison.

2. The method of claim 1 , wherein measuring impedance circle variables R e , and X e , and admittance circle variable G e , and B e comprises measuring impedance circle variables R e , and X e , and admittance circle variable G e , and B e around a first resonant frequency.

3. The method of claim 2 , further comprising measuring impedance circle variables R e , and X e , and admittance circle variable G e , and B e around a second resonant frequency.

4. The method of claim 1 , further comprising determining R ref , G ref , X ref , and B ref for an end effector of an ultrasonic device having empty and open jaws, an ultrasonic device having a tip bite on a tissue, or an ultrasonic device having a full bite on a tissue having a staple therein.

5. The method of claim 1 , further comprising determining R ref , G ref , X ref , and B ref for an end effector of an ultrasonic device clamping a dry chamois or clamping a wet chamois.

6. The method of claim 1 , wherein measuring impedance circle variables comprises calculating impedance circle variables R e , and X e , from a measured impedance circle radius and measured impedance circle offsets.

7. The method of claim 6 , wherein calculating impedance circle variables R e , and X e , from a measured impedance circle radius and measured impedance circle offsets comprises:
plotting, by the control circuit, real resistance values and imaginary impedance values on a two-dimensional graph; and
fitting, by the control circuit, the real resistance values and the imaginary impedance values to a circle having a radius r and offset values (a, b).

8. The method of claim 1 , wherein measuring admittance circle variables comprises calculating admittance circle variable G e , and B e from a measured admittance circle radius and measured admittance circle offsets.

9. The method of claim 8 , wherein calculating admittance circle variables G e , and B e , from a measured admittance circle radius and measured admittance circle offsets comprises:
plotting, by the control circuit, real conductance values and imaginary susceptance values on a two-dimensional graph; and
fitting, by the control circuit, the real conductance values and imaginary susceptance values to a circle having a radius r and offset values (a, b).

10. The method of claim 1 , further comprising measuring reference impedance circle variables R ref , and X ref , from a reference impedance circle radius and reference impedance circle offsets, and
measuring reference admittance circle variables G ref , and B ref from a reference admittance circle radius and reference admittance circle offsets.

11. The method of claim 10 , further comprising storing, by the control circuit, reference impedance circle variables R ref , and X ref and reference admittance circle variables G ref , and B ref in a memory circuit.

Assignees

• Cilag Gmbh Int

Inventors

• Nott Cameron R
• Stulen Foster B
• Quigley Fergus P
• Brady John E
• Trees Gregory A
• Sawhney Amrita Singh
• Ortiz Rafael J Ruiz
• Scoggins Patrick J
• Denzinger Kristen G
• Faller Craig N
• Jayme Madeleine C
• Cuti Alexander R
• Schneider Matthew S
• Boudreaux Chad P
• Black Brian D
• Rockman Maxwell T
• Bishop Gregory D
• Shelton Iv Frederick E
• Yates David C

Classifications

• G06F1/022

  Waveform generators, i.e. devices for generating periodical functions of time, e.g. direct digital synthesizers (G06F1/025, G06F1/03 take precedence) · CPC title

• A61B18/14

  Probes or electrodes therefor · CPC title

• A61B17/320068

  using mechanical vibrations, e.g. ultrasonic (A61B17/22012 takes precedence; dental tooth drilling devices operated by vibration A61C3/03; removing intra-ocular material using mechanical vibrations A61F9/00745) · CPC title

• A61B8/4483

  characterised by features of the ultrasound transducer · CPC title

• A61B2017/00106

  ultrasonic · CPC title