Magnetic Coupling for Sterile Instrument Drive Sealing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing minimally invasive medical procedures face challenges in securely coupling medical instruments to drive systems without mechanical connections, which can lead to misalignment issues and contamination risks.

Innovation Solution

A magnetic coupling system is introduced, where a motor in the instrument drive system rotates a magnetic coupling member, which in turn rotates a corresponding member in the medical instrument, allowing for secure sealing and alignment without mechanical force, and accommodating misalignment between the instrument and drive system axes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanical connection is used to couple the instrument to the drive system, then secure coupling is achieved, but misalignment issues and contamination risks occur

Engineering Contradiction:

Improvecoupling reliabilityVSAvoidmisalignment and contamination

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical connection system with a magnetic coupling system. The drive shaft and instrument shaft are coupled through magnetic attraction between magnets in the drive shaft and ferromagnetic material in the instrument shaft, eliminating mechanical contact. This substitution resolves the contradiction by providing secure coupling through magnetic force while avoiding misalignment and contamination issues associated with mechanical connections.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The magnetic field acts as an intermediary between the drive shaft and instrument shaft. Instead of direct mechanical contact, the magnetic field transmits rotational force and torque from the drive system to the instrument. This intermediary approach allows for flexible coupling that accommodates misalignment while maintaining secure connection and preventing contamination.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a magnetic coupling system is used, then sealing and alignment are improved, but manufacturing precision requirements increase

Engineering Contradiction:

Improvesealing and alignmentVSAvoidmagnetic coupling alignment

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent changes the coupling parameter from mechanical contact to magnetic attraction. By using magnetic force rather than mechanical engagement, the system becomes less sensitive to manufacturing tolerances and misalignment. The magnetic field can accommodate variations in shaft positioning while maintaining effective coupling, thereby improving reliability without requiring extremely high manufacturing precision.

Inventive Principle:

Principle #35Parameter changes

3Power

If mechanical coupling is used, then torque transmission is direct, but fluid ingress and debris contamination occur

Engineering Contradiction:

Improvetorque transmissionVSAvoidfluid ingress and contamination

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

The patent replaces mechanical torque transmission with magnetic torque transmission. The magnetic coupling allows torque to be transmitted through the barrier (sterile adapter or seal) without mechanical contact that would compromise the seal. This resolves the contradiction by maintaining effective power transmission while preventing fluid ingress and debris contamination through the magnetic field coupling.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 magnetic coupling system enhances reliability by preventing fluid and debris ingress, maintains alignment despite manufacturing tolerances, and ensures secure sealing, thereby improving the efficiency and sterility of minimally invasive medical procedures.

Implementation Method 1

a first magnetic coupling member within the first housing... a second magnetic coupling member within the second housing... The second magnetic coupling member is spaced from and magnetically coupled to the first magnetic coupling member

Methodology Applied

Scientific EffectMagnetic coupling: Magnetism

Data Source

PatentUS20240148458A1Systems and methods for coupling an instrument to an instrument drive system

Publication Date: 2024.05.09 INTUITIVE SURGICAL OPERATIONS INC

AI summary

A system comprises an instrument drive system that comprises a first housing, a first magnetic coupling member within the first housing, and a motor mechanically coupled to the first magnetic coupling member. The motor is configured to rotate the first magnetic coupling member. The system further comprises a medical instrument that comprises a second housing, a rotor within the second housing, and a second magnetic coupling member within the second housing and mechanically coupled to the rotor. The second magnetic coupling member is spaced from and magnetically coupled to the first magnetic coupling member. Rotation of the first magnetic coupling member causes rotation of the second magnetic coupling member and the rotor.