Elastic Tension Regulator for Surgical Cable Slack Compensation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Surgical instruments with actuation elements, such as cables or wires, often experience slack that leads to misalignment and derailment, compromising the precision and effectiveness of force transmission in teleoperated surgical systems.

Innovation Solution

A tension regulator comprising an elastically deformable body is coupled to the actuation element, which accommodates slack by diverting the path of the actuation element, maintaining tension without automated controls or manual adjustments, thus preventing misalignment and ensuring consistent force transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If conventional tensioning systems are used in remotely actuated instruments, then basic actuation function is provided, but the systems are bulky, complex, and require frequent maintenance

Engineering Contradiction:
Improvetensioning system complexityVSAvoidsystem reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent extracts the tensioning function from complex mechanical systems and implements it through a simple elastic element (spring) that is integrated directly into the actuation mechanism. This eliminates the need for separate tensioning devices, reducing overall system complexity while maintaining reliability through the inherent properties of the elastic element.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The elastic element automatically adjusts tension based on its mechanical properties, requiring no external control or maintenance. The spring self-regulates the tension force applied to the actuation element, eliminating the need for complex control systems and reducing maintenance requirements while ensuring consistent reliable operation.

Inventive Principle:
Principle #25Self-service

2Ease of manufacture

If conventional tensioning systems are used, then actuation is provided, but the systems require frequent maintenance and calibration

Engineering Contradiction:
Improvesystem simplicityVSAvoidmaintenance time
Core Design Contradiction:
Ease of manufactureVSLoss of time

Solution Approach 1:

The patent employs a simple elastic element that can be easily replaced if needed, rather than using complex mechanical tensioning systems that require maintenance. The simplicity of the elastic element makes it both easy to manufacture and replace, reducing maintenance time and costs while maintaining adequate performance for the application.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The elastic element requires no calibration or adjustment during operation, automatically maintaining proper tension through its mechanical properties. This self-regulating characteristic eliminates the need for periodic maintenance and calibration, reducing the loss of time associated with system upkeep.

Inventive Principle:
Principle #25Self-service

3Device complexity

If elastic elements are used for tensioning, then system complexity is reduced, but tension regulation capability is limited

Engineering Contradiction:
Improvetensioning system complexityVSAvoidtension regulation capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent applies different elastic elements with specific properties (different spring constants, materials, or geometries) to different locations in the system where specific tension characteristics are needed. This allows the simple elastic element to provide tailored tension regulation capabilities at each location without increasing overall system complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The elastic element provides dynamic tension adjustment based on the operational state of the actuation element. As the actuation element moves or changes state, the elastic element automatically adjusts the tension force applied, providing adaptability without requiring complex control mechanisms.

Inventive Principle:
Principle #15Dynamics

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

The tension regulator effectively compensates for slack in actuation elements, maintaining desired tension and preventing misalignment, thereby enhancing the precision and reliability of force transmission in surgical instruments, even as slack develops over time.

Implementation Method 1

the elastic element can be disposed at least partially within the lumen of the actuation element and can include an attachment at a first end of the elastic element and a second end of the elastic element

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3285676B1Tension regulator for actuation elements, and related remotely actuated instruments, and systems
Publication Date: 2022.07.27 INTUITIVE SURGICAL OPERATIONS INC
  • EP3285676B1 patent drawingFigure 1
  • EP3285676B1 patent drawingFigure 2
  • EP3285676B1 patent drawingFigure 3~4

AI summary

A device to regulate tension of an actuation element for actuating movement of a surgical instrument includes an elastically deformable body configured to be coupled to the actuation element. The deformable body is configured to elastically deform in response to a state of slack occurring in the actuation element. As slack occurs in the actuation element, the deformable body is configured to divert a path of the actuation element to accommodate the slack so the path of the actuation element differs from an axis the actuation element follows prior to the actuation element developing slack. A force transmission mechanism for a teleoperated surgical instrument includes a chassis, an actuation input mechanism, an actuation element, and a tension regulator coupled to the actuation element to compensate for slack of the actuation element.