Variable Beam Counterbalance for Precise Ophthalmic Laser Head Load

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Solution Overview

Problem

Existing ophthalmic laser systems face challenges in counterbalancing the heavy laser beam delivery head to prevent gravity-induced movement and transfer of forces to the patient's eye, while requiring precise and repeatable variations in the net load exerted on the eye during vertical travel.

Innovation Solution

A counterbalance mechanism using a balance beam, fulcrum, counterweight, and mechanical link to pivotably move the counterweight along the beam, adjusting the lever arm length to precisely vary the counterbalancing force based on the pivot angle of the beam.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed beam balance is used in the counterbalance mechanism, then the structure is simple and reliable, but the net load remains constant and cannot be adjusted for different surgical conditions

Engineering Contradiction:
Improveadjustability of net loadVSAvoidcomplexity of counterbalance mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by replacing the fixed beam balance with a variable beam balance that can dynamically adjust its position along the surgical instrument holder. This allows the counterbalance mechanism to adapt to different net load requirements during various surgical procedures while maintaining a relatively simple overall structure. The variable position capability enables the system to optimize balance for different instrument weights and surgical conditions.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the beam balance position is fixed, then the manufacturing and assembly are simpler, but the system cannot accommodate different surgical procedures requiring different net loads

Engineering Contradiction:
Improveaccommodation of different surgical proceduresVSAvoidease of manufacturing and assembly
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent applies segmentation by dividing the surgical instrument holder into multiple discrete positions where the beam balance can be selectively placed. This segmentation approach allows the system to accommodate different surgical procedures by positioning the beam balance at appropriate locations along the holder. The segmented design maintains manufacturing simplicity while providing the necessary adaptability for various net load requirements.

Inventive Principle:
Principle #1Segmentation

3Productivity

If a variable beam balance is implemented to provide variable net load, then different surgical conditions can be optimized, but the device complexity increases

Engineering Contradiction:
Improvesurgical efficiencyVSAvoidcomplexity of counterbalance mechanism
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The variable beam balance mechanism implements dynamics by allowing the balance position to be adjusted along the surgical instrument holder. This dynamic positioning capability enables optimization of surgical efficiency for different procedures and instruments by matching the counterbalance position to the specific net load requirements, while keeping the overall device complexity manageable through a straightforward mechanical design.

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

Enables precise and repeatable variation in the net load exerted on the patient's eye, allowing for controlled applanation force adjustments during vertical travel of the laser head, enhancing stability and precision in ophthalmic procedures.

Implementation Method 1

a variable beam balance positioned at a selected position along the longitudinal axis of the surgical instrument holder to compensate for the weight of the surgical instrument

Methodology Applied
Scientific EffectGravitation: Gravitation

Implementation Method 2

Counterbalance mechanisms are employed in ophthalmic laser systems to compensate for the weight of the surgical instrument, thereby facilitating smooth and precise manual manipulation

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentEP4362872B1Counterbalance mechanism in ophthalmic laser system employing a variable beam balance to provide a variable net load
Publication Date: 2026.04.29 AMO DEVELOPMENT LLC
  • EP4362872B1 patent drawingFigure 1
  • EP4362872B1 patent drawingFigure 2~3A
  • EP4362872B1 patent drawingFigure 3B~3C

AI summary

A counterbalance mechanism in an ophthalmic laser system balances the weight of the laser beam delivery head and provides small, precise and repeatable variations in the net load exerted by the laser head on the patient's eye over a defined distance of travel. The counterbalance mechanism includes a balance beam pivotably mounted on a support block, with the laser head and a counterweight mounted on its two ends. The counterweight is movable along the balance beam via a linear motion bearing. A mechanical link links the counterweight to the support block; the link has a predefined length and is pivotable around its respective connection points on the support block and the counterweight. When the balance beam pivots, the link causes the counterweight to move along the balance beam, thereby changing the mechanical advantage of the counterweight and varies the counterbalancing force to provide variations in the net load.