Electrosurgical Clamp Closure Sensor for Tissue Load Estimation
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Solution Overview
Problem
Existing electrosurgical instruments face challenges in accurately measuring tissue load force and jaw position during tissue sealing, which can lead to incomplete sealing or tissue slipping due to the complexity and cost of incorporating force sensors directly in the end effector.
Innovation Solution
The use of clamp closure sensors and sensor receiver mechanisms within the handle assembly to estimate tissue load force and jaw position, allowing for real-time feedback without the need for direct measurement at the end effector, using sensors such as Hall Effect sensors or reflective optocouplers to provide sensor information to a control unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If force sensors are incorporated directly in the end effector to accurately measure tissue load force and jaw position, then measurement precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent introduces a biasing feature (spring mechanism) as an intermediary between the jaw closure system and the sensor. This biasing feature transmits the tissue load force to the sensor, allowing indirect measurement of jaw position and tissue load. The sensor is positioned to detect the position of the biasing feature, which correlates to jaw closure status and tissue compression force, thereby achieving accurate measurement without direct sensor placement in the end effector.
Solution Approach 2:
The patent replaces complex direct mechanical sensing in the end effector with an optical or electromagnetic sensor system in the handle assembly. By using the biasing feature to mechanically couple the tissue load to a detectable position change in the handle, the system substitutes direct mechanical measurement with indirect detection, reducing device complexity while maintaining measurement precision.
2Reliability
If force sensors are incorporated directly in the end effector to accurately measure tissue load force, then reliability of tissue sealing is improved, but manufacturing cost increases
Solution Approach 1:
The biasing feature serves as a mechanical intermediary that translates tissue load force into positional information detectable by sensors in the handle assembly. This approach maintains reliable tissue sealing monitoring by accurately detecting jaw position and tissue compression, while avoiding the high cost of direct force sensor integration in the end effector.
Solution Approach 2:
The system creates a mechanical copy or representation of the tissue load force through the biasing feature's position. Instead of directly measuring force with expensive sensors, the patent measures the position of the biasing feature, which replicates the force information in a more cost-effective manner using standard position detection sensors.
3Device complexity
If sensors are placed in the handle assembly to estimate tissue load force indirectly, then device complexity is reduced, but measurement precision may deteriorate
Solution Approach 1:
The patent implements a feedback mechanism where the sensor continuously monitors the position of the biasing feature, and this information is fed back to the control system. The control system uses this feedback to adjust jaw closure and maintain accurate tissue compression, compensating for any estimation errors and ensuring precise tissue sealing despite indirect measurement.
Solution Approach 2:
The patent replaces complex direct force measurement mechanics with a simpler position detection system. By using the biasing feature as a mechanical transducer that converts force into position, the system substitutes expensive force sensors with more accurate and reliable position sensors, actually improving measurement precision while reducing complexity.
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
This approach provides a cost-effective and space-efficient method for determining tissue load and jaw position, ensuring reliable tissue sealing by preventing over-compression and detecting when tissue is slipping, thus improving the sealing process.
Implementation Method 1
using sensors such as Hall Effect sensors or reflective optocouplers to provide sensor information to a control unit
Implementation Method 2
using sensors such as Hall Effect sensors or reflective optocouplers to provide sensor information to a control unit
Data Source
AI summary
An electrosurgical instrument includes a shaft assembly, an end effector, an input actuator, a biasing feature, an end of stroke feature, a first clamp closure sensor, a second clamp closure sensor, and a control unit. The end effector includes an energized feature, a first jaw, and a second jaw. The first clamp closure sensor is configured to produce first sensor information relating to movement of the input actuator. The second clamp closure sensor is configured to produce second sensor information relating to deflection of the biasing feature in response to a tissue load force between the first and second jaws. Based on each of the first and second sensor information, the control unit is configured to determine the tissue load force exerted on the end effector, and a position of one of the first and second jaws relative to the other of the first and second jaws.