Surgical Instrument Shaft Interface for Self-Aligning Connection

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Solution Overview

Problem

The alignment and connection of surgical instruments with instrument drive units in robotic surgical systems are often difficult and time-consuming due to unknown positions and orientations of connecting features, requiring trial and error calibration.

Innovation Solution

The design includes an interface with oblique end surfaces on drive and driven shafts that engage via specific connection pathways, allowing for precise alignment and secure connection without calibration, using a connection hub and connecting member with axially translatable protrusions for securement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional connection methods with unknown positions and orientations are used, then the connecting features can be mated, but the alignment process becomes difficult and time-consuming requiring trial and error calibration

Engineering Contradiction:
Improveease of connectionVSAvoidinstallation time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The oblique end surfaces are pre-configured on the drive shaft and driven shaft with specific geometric relationships. This preliminary geometric configuration enables automatic self-alignment when the shafts are engaged, eliminating the need for trial-and-error calibration during installation. The pre-set angular surfaces guide the connection process and ensure proper orientation without requiring time-consuming manual adjustment.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If trial and error calibration is performed to align connecting features, then proper connection can be achieved, but the process becomes difficult and problematic

Engineering Contradiction:
Improveconnection reliabilityVSAvoidease of calibration
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The oblique end surfaces are designed to automatically self-align the drive shaft and driven shaft during engagement. When the shafts are brought together, the angular surfaces naturally guide them into the correct relative position and orientation without external intervention. This self-aligning mechanism eliminates the need for difficult manual calibration while ensuring reliable and repeatable connections.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If precise alignment is achieved through calibration, then proper torque transfer can be ensured, but the installation process becomes time-consuming

Engineering Contradiction:
Improvealignment precisionVSAvoidinstallation speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The precise angular geometry of the oblique end surfaces is pre-determined during manufacturing. This preliminary precision engineering ensures that when the shafts engage, the pre-configured surfaces automatically achieve the required alignment precision for reliable torque transfer. The precision is built into the component geometry itself, eliminating the need for time-consuming field calibration while maintaining high alignment accuracy.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3099265B1Interfaces for surgical systems
Publication Date: 2021.09.15 COVIDIEN LP
  • EP3099265B1 patent drawingFigure 1
  • EP3099265B1 patent drawingFigure 2
  • EP3099265B1 patent drawingFigure 3

AI summary

An interface for a surgical system includes an instrument drive unit and a surgical instrument. The instrument drive unit includes a connection hub and at least one drive shaft rotatably supported in the connection hub. The at least one drive shaft extends between a first end and a second end having an oblique end surface. The surgical instrument is releasably connectable to the instrument drive unit and includes a connecting member and at least one driven shaft rotatably supported in the connecting member. The at least one driven shaft extends between a first end and a second end. The second end has an oblique end surface corresponding to the oblique end surface of the at least one drive shaft. The oblique end surfaces are configured such that the connecting member is connectible with the connection hub via a first connection pathway and a second connection pathway.