Galvanic Isolation via Fiber-Optic Medical Device Interface

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Medical devices, such as dialysis machines, face challenges in protecting patients and operators from dangerous electrical voltages and leakage currents, while also being susceptible to electromagnetic interference, which can compromise safety and accuracy in patient treatment.

Innovation Solution

A communication interface design that incorporates a fiber-optic data connection for electrically non-conductive signal transmission, ensuring galvanic isolation with a predetermined dielectric strength, and an external power supply that maintains safe voltage levels, reducing the risk of electrical hazards and interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If a communication interface is added to transmit device and patient data, then data communication capability is improved, but electrical safety and protection from dangerous voltages deteriorates

Engineering Contradiction:
Improvedata communication capabilityVSAvoidelectrical safety
Core Design Contradiction:
Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an optical converter as an intermediary device that converts electrical signals to optical signals for transmission through fiber optic cables. This mediator breaks the electrical continuity between the medical device and the external network, allowing data communication while preventing dangerous electrical voltages and leakage currents from reaching the patient side.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the traditional electrical signal transmission system with an optical signal transmission system using fiber optic cables. This substitution eliminates the conductive electrical path that poses safety risks, while maintaining full data communication capability through light-based signal transmission.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Loss of information

If electrical communication cables are used for network connection, then data transmission is enabled, but susceptibility to electromagnetic interference increases

Engineering Contradiction:
Improvedata transmission capabilityVSAvoidelectromagnetic interference susceptibility
Core Design Contradiction:
Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The patent substitutes electrical signal transmission with optical signal transmission through fiber optic cables. Optical fibers are inherently immune to electromagnetic interference since they transmit data using light rather than electrical currents, thereby eliminating the susceptibility to electromagnetic interference while maintaining data transmission capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The optical converter acts as an intermediary that transforms electrical signals into optical signals before transmission. This intermediary process converts the data into a form (optical signals) that is immune to electromagnetic interference, protecting the medical device from external electromagnetic disturbances.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If galvanic isolation with high dielectric strength is implemented, then electrical safety is improved, but device complexity increases

Engineering Contradiction:
Improveelectrical safetyVSAvoidcommunication interface complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent uses optical converters as intermediary devices that provide galvanic isolation by converting electrical signals to optical signals. This approach achieves high dielectric strength (electrical safety) without requiring complex isolation circuits, as the galvanic isolation is inherently provided by the optical conversion process itself.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces complex electrical isolation circuits with a simpler optical transmission system. By substituting electrical signal transmission with optical signal transmission, the system achieves superior galvanic isolation with fewer components and reduced complexity compared to traditional electrical isolation methods.

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 solution effectively protects patients and operators from electrical hazards and minimizes the impact of electromagnetic interference, ensuring safe and accurate operation of medical devices by using fiber-optic connections and safe voltage supplies.

Implementation Method 1

At least one segment of the communication path is designed to transmit communication signals in an electrically non-conductive manner and has an electrical or galvanic isolation between input and output or output and input of the segment with a predetermined first dielectric strength

Methodology Applied
Scientific EffectOptical signal transmission: Optical Fibre

Implementation Method 2

which has a converter circuit, which converts electrical signals into optical signals and/or optical signals into electrical signals

Methodology Applied
Scientific EffectElectro-optic conversion: Electro-Optic Effects

Implementation Method 3

The first power supply is set up to ensure a supply voltage below a predetermined maximum voltage that is considered safe

Methodology Applied
Scientific EffectVoltage regulation:

Data Source

PatentEP3658200B1Medical device having a communication interface designed for protecting patients and operators
Publication Date: 2022.09.07 FRESENIUS MEDICAL CARE DEUTSCHLAND GMBH
  • EP3658200B1 patent drawingFigure 1~2
  • EP3658200B1 patent drawingFigure 3~4
  • EP3658200B1 patent drawingFigure 5~6

AI summary

The invention relates to a medical device having at least one housing, electrical and/or electronic components arranged within the housing, and a user interface. The medical device additionally has a receptacle device, accessible from outside of the housing, of a first communication interface for receiving a proximal end of a medium conducting communication signals. A distal end of the medium conducting communication signals is provided for connection to a second communication interface belonging to a communication network. A communication route between the distal end of the medium conducting communication signals and electrical components of the medical device, which are internal to the device and connected for communication to the first communication interface, has at least two segments. At least one of the segments electrically non-conductively transfers communication signals and has an electrical separation between the input and output or between the output and input of the segment, having a specified first dielectric strength.