Surgical Instrument Sheath Locking Collar for Secure Easy Removal

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Solution Overview

Problem

Existing surgical instruments used in minimally invasive procedures face challenges in cleaning and sterilization due to their complex mechanical design, necessitating reusable instruments that require stringent cleaning and sterilization procedures, and there is a need for sheaths that are easy to install and remove while providing robust attachment to prevent accidental displacement.

Innovation Solution

A sheath for surgical instruments featuring a retention mechanism with a locking collar that engages with a connector portion of the instrument, allowing easy installation and removal, and includes resilient members that lock the sheath in place to prevent axial and rotational movement, made from biocompatible materials suitable for extrusion and molding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If surgical instruments are made reusable to reduce cost, then cost per use is reduced, but cleaning and sterilization procedures become more difficult due to complex mechanical components and tight spaces

Engineering Contradiction:
Improveinstrument reusabilityVSAvoidcleaning and sterilization difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The sheath is designed as a separate, removable component that can be detached from the surgical instrument. This segmentation allows the sheath to be removed and discarded after a single use, while the expensive instrument with complex mechanical components can be reused. The sheath acts as a protective barrier during surgery, preventing contamination of the instrument, and can be easily removed without requiring disassembly of the instrument's complex internal components.

Inventive Principle:
Principle #1Segmentation

2Reliability

If sheaths are designed with robust attachment to prevent accidental removal, then attachment reliability is improved, but ease of installation and removal by surgical personnel deteriorates

Engineering Contradiction:
Improvesheath attachment securityVSAvoidsheath installation and removal ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The locking collar is designed with resilient members that can dynamically change state between locked and unlocked configurations. During normal use, the resilient members engage with the instrument to provide secure attachment. When force is applied to the release feature, the resilient members deform to disengage, allowing easy removal. This dynamic behavior allows the same structure to provide both secure attachment during surgery and easy removal when needed.

Inventive Principle:
Principle #15Dynamics

3Reliability

If a locking mechanism is added to prevent sheath displacement, then attachment reliability is improved, but device complexity increases

Engineering Contradiction:
Improvesheath position stabilityVSAvoidretention mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The resilient members automatically engage with the instrument when the sheath is installed, providing self-locking without requiring additional actuators or complex mechanisms. The release feature simply needs to apply force to deform the resilient members, and they automatically disengage when the locking engagement is broken. This self-service approach provides reliable locking while keeping the mechanism simple and easy to operate.

Inventive Principle:
Principle #25Self-service

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

Facilitates efficient cleaning and sterilization of surgical instruments by enabling easy and secure attachment and removal of sheaths, reducing the risk of parts failure and enhancing the reliability of reusable instruments.

Implementation Method 1

a locking collar extending from the sleeve attachment portion, wherein the locking collar is configured to receive a connector portion of a surgical instrument. The locking collar further includes a locking feature movable between a first configuration, in which the locking feature is engaged with the connector portion to retain the sheath in position on the surgical instrument, and a second configuration, in which the locking feature is in a laterally outward deflected position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3399939B1Sheathes for surgical instruments, and related devices
Publication Date: 2026.02.11 INTUITIVE SURGICAL OPERATIONS INC
  • EP3399939B1 patent drawingFigure 1
  • EP3399939B1 patent drawingFigure 2~3
  • EP3399939B1 patent drawingFigure 4A~4B

AI summary

A sheath for a surgical instrument may include a sleeve having a distal end and proximal end, and a retention mechanism at a proximal end portion of the sleeve. The retention mechanism may comprise a sleeve attachment portion configured to be attached to the sleeve at the proximal end portion, and a locking collar extending from the sleeve attachment portion, wherein the locking collar is configured to receive a connector portion of a surgical instrument. The locking collar further may include a locking feature movable between a first configuration, in which the sheath is moveable relative to the surgical instrument, and a second configuration, in which the locking feature is configured to engage with the connector portion to retain the sheath in position on the surgical instrument.