Planetary Gear Adapter Assembly for Articulated Surgical Torque Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing surgical devices with rotary motion-powered handle assemblies are not compatible with linear-driven end effectors, requiring significant torque through articulation joints, leading to wear and reduced device lifespan.

Innovation Solution

An adapter assembly with a planetary gear assembly placed distal to the articulation joint, reducing torque requirements by approximately 75-80% through a gear ratio, minimizing stress on gear teeth and bearings, and extending the device's usable life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a lead screw/nut assembly is used to convert rotary motor torque to linear force in a motor powered stapling device, then the linear driven end effector becomes compatible with rotary motion powered surgical devices, but significant torque is required through the articulation joint leading to wear and reduced device lifespan

Engineering Contradiction:
Improvecompatibility between rotary-driven surgical device and linear-driven end effectorVSAvoiddevice lifespan
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

A planetary gear assembly is introduced as an intermediary mechanism between the rotary motor and the lead screw assembly. The planetary gears reduce the torque required at the articulation joint by providing a gear ratio, while still enabling the conversion of rotary motion to linear motion through the lead screw/nut mechanism. This mediator reduces stress on the articulation joint and extends device lifespan.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The planetary gear assembly changes the torque parameter by providing a gear reduction ratio. This allows the motor to operate at higher torque with lower speed, while the output to the lead screw is at lower torque with appropriate speed, thereby reducing the torque burden on the articulation joint and extending device reliability.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If linear force is passed through a 90° bend in the articulation joint, then the end effector can be positioned at different angles, but significant torque losses occur and increased torque is needed through the articulation joint

Engineering Contradiction:
Improvearticulation flexibilityVSAvoidtorque loss
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The planetary gear assembly serves as an intermediary that provides torque multiplication before the force needs to navigate the articulation bend. By reducing the torque requirement at the joint, the system can maintain articulation flexibility while minimizing energy loss during the 90° bend transmission.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The planetary gears perform preliminary torque reduction before the force is transmitted through the articulation joint. This preliminary action ensures that the torque load on the bent joint is minimized, reducing energy loss and allowing smooth articulation movement.

Inventive Principle:
Principle #10Preliminary action

3Power

If high torque is transmitted through the articulation joint to drive the linear end effector, then the clamping and stapling operations can be performed, but wear increases and device life is reduced

Engineering Contradiction:
Improveclamping and stapling capabilityVSAvoiddevice usable life
Core Design Contradiction:
PowerVSDuration of action of stationary object

Solution Approach 1:

The planetary gear assembly changes the torque-speed parameters by providing gear reduction. The motor operates at high torque and low speed, while the planetary gears reduce the torque transmitted through the articulation joint. This parameter transformation maintains the power needed for clamping and stapling operations while extending device usable life by reducing wear.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The planetary gear system acts as a mediator between the motor and the articulation joint, transforming the torque parameters to reduce stress on the joint while maintaining sufficient power for surgical operations. This intermediary protection mechanism extends the stationary components' duration of action.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 adapter assembly effectively reduces torque transmission through articulation joints, minimizing wear and extending the lifespan of surgical devices by utilizing a planetary gear assembly to optimize power delivery from rotary-driven surgical devices to linear-driven end effectors.

Implementation Method 1

a plurality of planetary gears disposed around and in meshing engagement with the sun gear and the ring gear. The adapter assembly further includes a spider gear operably coupled to the plate and disposed proximal of the ring gear

Methodology Applied
Scientific EffectPlanetary gear mechanism: Epicyclic Gearing

Implementation Method 2

reducing torque requirements by approximately 75-80% through a gear ratio, minimizing stress on gear teeth and bearings

Methodology Applied
Scientific EffectMechanical advantage through gear ratio: Mechanical Advantage

Implementation Method 3

The bevel gear assembly includes a proximal end in mechanical engagement with a distal end portion of the firing shaft, the bevel gear assembly for transferring torque through an articulation joint of the adapter assembly

Methodology Applied
Scientific EffectBevel gear mechanism: Gear

Data Source

PatentEP3195812B1Adapter assembly with planetary gear drive for interconnecting electromechanical surgical devices and surgical loading unit, and surgical systems thereof
Publication Date: 2021.07.21 COVIDIEN LP
  • EP3195812B1 patent drawingFigure 1
  • EP3195812B1 patent drawingFigure 2~3
  • EP3195812B1 patent drawingFigure 4~5

AI summary

The present disclosure relates to adapter assemblies for use with and to electrically and mechanically interconnect electromechanical surgical devices and surgical loading units, and to surgical systems including handheld electromechanical surgical devices and adapter assemblies for connecting surgical loading units to the handheld electromechanical surgical devices.