Methods for controlling temperature in ultrasonic device

Patent metadata

Field	Value
Publication number	US-11701139-B2
Application number	US-202217667657-A
Country	US
Kind code	B2
Filing date	Feb 9, 2022
Priority date	Mar 8, 2018
Publication date	Jul 18, 2023
Grant date	Jul 18, 2023

Abstract

A generator, ultrasonic device, and method for controlling a temperature of an ultrasonic blade are disclosed. A control circuit coupled to a memory determines an actual resonant frequency of an ultrasonic electromechanical system comprising an ultrasonic transducer coupled to an ultrasonic blade by an ultrasonic waveguide. The actual resonant frequency is correlated to an actual temperature of the ultrasonic blade. The control circuit retrieves from the memory a reference resonant frequency of the ultrasonic electromechanical system. The reference resonant frequency is correlated to a reference temperature of the ultrasonic blade. The control circuit then infers the temperature of the ultrasonic blade based on the difference between the actual resonant frequency and the reference resonant frequency. The control circuit controls the temperature of the ultrasonic blade based on the inferred temperature.

First claim

The invention claimed is:

1. A computer-implemented interactive surgical system for controlling an estimated temperature of an ultrasonic blade, the system comprising:
a generator configured to communicate with a modular control tower, the modular control tower in data communication with a modular communication hub, the modular communication hub in data communication with one or more modular devices located in one or more operating theaters of a healthcare facility, the generator comprising a control circuit coupled to a memory, the control circuit configured to:
determine an actual resonant frequency of an ultrasonic electromechanical system comprising an ultrasonic transducer coupled to an ultrasonic blade by an ultrasonic waveguide, wherein the actual resonant frequency is correlated to an actual temperature of the ultrasonic blade;
retrieve from the memory a reference resonant frequency of the ultrasonic electromechanical system, wherein the reference resonant frequency is correlated to a reference temperature of the ultrasonic blade;
infer an inferred temperature of the ultrasonic blade based on a difference between the actual resonant frequency and the reference resonant frequency;
control the estimated temperature of the ultrasonic blade based on the inferred temperature;
generate a temperature estimator and a state space model of the inferred temperature of the ultrasonic blade as a function of the actual resonant frequency of the ultrasonic electromechanical system based on a set of non-linear state space equations;
apply a Kalman filter to improve the temperature estimator and the state space model;
apply a state estimator in a feedback loop of the Kalman filter;
control power applied to the ultrasonic transducer; and
regulate the estimated temperature of the ultrasonic blade,
wherein to determine the actual resonant frequency of the ultrasonic electromechanical system, the control circuit is further configured to determine a phase angle φ between a voltage V g (t) and a current I g (t) signal applied to the ultrasonic transducer,
wherein the state space model is defined by:

[

F
˙

n

T
˙

]

=

f
⁡
(

t
,

T
⁡
(
t
)

,

F
n

(
t
)

,

E
⁡
(
t
)

)

⁢

y
.

=

h
⁡
(

t
,

T
⁡
(
t
)

,

F
n

(
t
)

,

E
⁡
(
t
)

)

.

wherein:
{dot over (F)} n represents a rate of change of a time (t) dependent natural frequency F n (t) of the ultrasonic electromechanical system;
{dot over (T)} represents a rate of change of the actual temperature of the ultrasonic blade with respect to the time (t) dependent natural frequency F n (t);
T(t) represents a time (t) dependent actual temperature of the ultrasonic blade;
E(t) represents a time (t) dependent energy;
t represents the time; and
y represents an observability of variables that are measurable and observable including the time dependent natural frequency F n (t) of the ultrasonic electromechanical system, the time dependent actual temperature T(t) of the ultrasonic blade, observable as the temperature estimator, the time dependent energy E(t) applied to the ultrasonic blade, and time t, and
wherein a state variance of the state estimator of the Kalman filter is defined by:
(σ k − ) 2 =σ k-1 − +σ P k 2 and

a gain K of the Kalman filter is defined by:

K
=

(

σ
k
-

)

2

(

σ
k
-

)

2

+

σ
m
2

.

wherein:
(σ k − ) is a variance of state k;
(σ k-1 − ) is a variance of the previous state k−1;
(σ Pk − ) is a predicted variance of state k; and
(σ m − ) is an observed system variance.

2. The computer-implemented interactive surgical system of claim 1 , further comprising an imaging module in data communication with the modular control tower.

3. The computer-implemented interactive surgical system of claim 2 , wherein the imaging module is in data communication with a surgical device.

4. The computer-implemented interactive surgical system of claim 1 , further comprising one or more surgical instruments in data communication with the modular communication hub.

5. The computer-implemented interactive surgical system of claim 1 , wherein the modular communication hub is in data communication with an internet cloud resource.

6. The computer-implemented interactive surgical system of claim 1 , further comprising a surgical robot h

Assignees

• Cilag Gmbh Int

Inventors

• Nott Cameron R
• Quigley Fergus P
• Sawhney Amrita S
• Leuck Stephen M
• Black Brian D
• Roberson Eric M
• Denzinger Kristen G
• Scoggins Patrick J
• Faller Craig N
• Jayme Madeleine C
• Gee Jacob S

Classifications

• A61B17/320068 Primary

  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

• A61B17/00234

  for minimally invasive surgery (A61B17/0218, A61B17/0469, A61B17/12013, A61B17/1285, A61B17/29, A61B17/320016 take precedence) · CPC title

• A61B17/22012

  in direct contact with, or very close to, the obstruction or concrement (for removing obstructions in blood vessels by laser A61B18/245) · CPC title

• A61B17/3211

  Surgical scalpels, knives; Accessories therefor · CPC title

• A61B17/320092 Primary

  with additional movable means for clamping or cutting tissue, e.g. with a pivoting jaw · CPC title