Surgical Instrument Actuator with Force Balancing Mechanism

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In minimally invasive surgical instruments, forces applied to actuate end effectors often undesirably affect intermediate structures like wrist mechanisms, leading to unwanted movement and loss of control.

Innovation Solution

A surgical instrument design featuring a drive element that transmits forces to a distal end component while an opposing force is applied to the drive element housing, minimizing or eliminating actuation forces at intermediate joints, thereby stabilizing the distal end component and maintaining control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a drive element is used to transmit forces to the end effector, then actuation of the end effector is achieved, but unwanted forces are applied to intermediate wrist mechanisms causing undesired movement

Engineering Contradiction:

Improvecontrol of end effectorVSAvoidstability of wrist mechanism

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

A counterbalance element is introduced as an intermediary component between the drive element and the wrist mechanism. This counterbalance element applies an opposing force to the drive element housing, which mediates and cancels out the unwanted forces transmitted to the wrist mechanism, allowing the drive element to actuate the end effector without causing undesired wrist movement

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The counterbalance element functions as a mechanical counterweight system where a force opposite to the drive element force is applied to the drive element housing. This counterbalancing force cancels out the net force transmitted to intermediate joints, enabling stable wrist mechanism operation while maintaining end effector actuation capability

Inventive Principle:

Principle #8Anti-weight (Counterweight)

2Productivity

If force is applied to actuate the end effector, then the end effector moves as desired, but intermediate joints experience unwanted forces causing loss of control

Engineering Contradiction:

Improveactuation efficiencyVSAvoidcontrol precision

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The drive element housing serves as an intermediary structure that isolates the actuation forces from the wrist mechanism. By applying the counterbalancing force to the housing rather than directly to the wrist, the system maintains efficient force transmission to the end effector while protecting the intermediate joints from unwanted forces

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The counterbalance element provides a counterbalancing force that eliminates net forces on intermediate joints during actuation. This allows the drive element to efficiently move the end effector through its full range of motion without compromising control precision, as the wrist mechanism experiences minimal disturbing forces

Inventive Principle:

Principle #8Anti-weight (Counterweight)

Data Source

PatentUS8597280B2Surgical instrument actuator

Publication Date: 2013.12.03 INTUITIVE SURGICAL OPERATIONS INC

AI summary

A surgical instrument body has a proximal portion, a distal portion, and a joint between the proximal and distal instrument body portions. A drive element housing extends through the proximal and distal instrument body portions and through the joint. A force to actuate a component at the distal end of the instrument body is applied to the drive element. A second force in the opposite direction is applied to the drive element housing, and this second force is also applied to the component. The opposite direction forces stabilize the component so that when the distal component is actuated, the actuation does not significantly affect the joint position.