Ultrasonic End Effector Temperature Estimation Across Heating and Cooling
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Solution Overview
Problem
Conventional surgical systems lack the ability to efficiently monitor and control the temperature of ultrasonic instruments during and between heating and cooling cycles, leading to inefficiencies and potential tissue damage due to unknown blade temperatures.
Innovation Solution
A surgical system that estimates the temperature of an ultrasonic instrument's end effector by using different temperature models based on resonance frequency and input current, transitioning between heating and cooling cycles to provide continuous temperature readings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the ultrasonic instrument is deactivated after heating cycle, then the blade cools down, but the cooling rate is unknown and may remain too hot for a period of time
Solution Approach 1:
The system continuously monitors the ultrasonic instrument's characteristics (resonance frequency, input current, input voltage) and uses temperature models to estimate blade temperature in real-time, providing feedback to the operator about the cooling rate and when the blade is safe to use again
Solution Approach 2:
The patent replaces direct thermal sensing with electrical/mechanical parameter monitoring, using resonance frequency and electrical characteristics to infer temperature without physical contact or direct thermal sensors on the blade
2Productivity
If the blade oscillates at high power to cut and cauterize tissue, then cutting and sealing is achieved, but the blade reaches high temperatures that may cause tissue damage
Solution Approach 1:
The system monitors electrical characteristics (input current, voltage, resonance frequency) during high-power operation and estimates temperature in real-time, alerting the operator when the blade approaches dangerous temperatures even during active use
Solution Approach 2:
The system performs preliminary temperature estimation before tissue contact by monitoring resonance frequency and electrical characteristics, allowing the operator to adjust power or pause operation to cool the blade proactively rather than reactively
3Measurement precision
If the system monitors temperature continuously during heating and cooling cycles, then real-time temperature control is achieved, but device complexity increases
Solution Approach 1:
The patent uses electrical and mechanical parameter monitoring (resonance frequency, input current, voltage) to substitute for direct thermal sensing, achieving continuous temperature estimation through existing instrument characteristics rather than adding complex thermal sensors
Solution Approach 2:
The system uses existing multi-functional measurements (electrical characteristics, resonance frequency) for both operational control and temperature estimation, making the monitoring system serve multiple purposes without adding dedicated temperature sensors
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables efficient temperature estimation and control of the ultrasonic instrument, reducing the risk of tissue damage by providing real-time temperature feedback to the operator.
Implementation Method 1
the blade oscillates against a piece of tissue, thereby producing heat due to friction between the blade and the tissue during the oscillation
Implementation Method 2
the system may determine the temperature of the blade based on one or more characteristics (e.g., an input voltage, an input current, a resonance frequency, etc.) of the instrument
Data Source
AI summary
A method performed by a surgical system. The method determines a resonance frequency of an end effector of an ultrasonic instrument, and determines whether the end effector of the ultrasonic instrument is in a heating state or a cooling state. Responsive to determining that the end effector is in the heating state, the method estimates a temperature of the end effector based on output of a first temperature model that has input based on the resonance frequency. Responsive, however, to determining that the end effector is in the cooling state, the method estimates the temperature of the end effector based on output of a second temperature model that has input based on the resonance frequency. The method presents a notification based on the estimated temperature.