Robotic Arm Five-Bar Spherical Linkage for Endoscopic Camera

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Solution Overview

Problem

Traditional minimally invasive surgery requires high surgical skill due to the need for unnatural hand motions to control surgical instruments at a distance from the surgeon's hands, making it challenging to perform precise movements in robotically assisted surgeries.

Innovation Solution

A robotic arm equipped with a parallel spherical five-bar linkage that supports the laparoscopic camera, allowing the tool shaft and cannula to pivot about a remote center of spherical rotation, enabling precise motion control and reducing lateral movement at the incision site, thereby facilitating more intuitive and precise surgical procedures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If traditional endoscopic instruments are used with long tool shafts, then minimally invasive surgery can be performed through small incisions, but the surgeon's hand motions become unnatural and imprecise due to the distance from the hands to the surgical site

Engineering Contradiction:

Improveunnatural hand motionsVSAvoidprecision of surgical movements

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The robotic arm acts as an intermediary between the surgeon's control inputs and the surgical instrument at the distal end. The parallel spherical five-bar linkage mechanism serves as a mechanical mediator that transforms control motions into precise surgical tool movements while maintaining the natural relationship between the instrument and cannula, eliminating the need for the surgeon to directly manipulate long tool shafts

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the traditional direct mechanical control system (surgeon's hands directly manipulating instrument handles) with a robotic mechanical system. The robotic arm with parallel spherical five-bar linkage substitutes the surgeon's direct mechanical interaction with the instrument, providing precise motion control and eliminating unnatural hand motions associated with long tool shaft manipulation

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If the robotic arm allows free movement of the tool shaft, then the camera can be positioned flexibly, but lateral movement at the incision site increases which complicates the surgical procedure

Engineering Contradiction:

Improvepositioning flexibility of cameraVSAvoidlateral movement at incision

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The robotic arm is segmented into multiple interconnected components (ground link, inboard links, outboard links) that can move independently through controlled degrees of freedom. This segmentation allows the camera to be positioned flexibly in three-dimensional space while the parallel spherical five-bar linkage constrains the motion to prevent unwanted lateral movement at the incision site

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The parallel spherical five-bar linkage employs spherical geometry where all rotation axes intersect at a common remote center of spherical rotation. This spherical arrangement allows the tool shaft to pivot freely in multiple directions for flexible camera positioning while maintaining a fixed insertion point, eliminating lateral movement at the incision site through the geometric constraint of spherical motion

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Device complexity

If a simple robotic arm structure is used, then device complexity is reduced, but motion precision and control accuracy deteriorate

Engineering Contradiction:

Improvestructure of robotic armVSAvoidmotion control precision

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The parallel spherical five-bar linkage uses spherical geometry with all rotation axes intersecting at a common remote center. This geometric configuration inherently provides precise motion control and accurate positioning without requiring complex control systems, achieving high precision through elegant geometric constraints rather than complex mechanisms

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The robotic arm employs a dynamic parallel mechanism where multiple links move simultaneously in a coordinated fashion. The parallel spherical five-bar linkage provides real-time motion constraints and stability during movement, enabling precise control through the dynamic interaction of multiple moving components rather than static rigid structures

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS8167873B2Center robotic arm with five-bar spherical linkage for endoscopic camera

Publication Date: 2012.05.01 INTUITIVE SURGICAL OPERATIONS INC

AI summary

A robotic arm including a parallel spherical five-bar linkage with a remote center of spherical rotation. The robotic arm movably supports an endoscopic camera. Two outboard links are pivotally coupled together. At least one of the two outboard links supports the endoscopic camera. Two inboard links are respectively pivotally coupled to the two outboard links such that the two inboard links are able to cross over one another. The two inboard links moveably support the two outboard links. A ground link is pivotally coupled to the two inboard links. The ground link moveably supports the two inboard links.