Orthogonal PCB Charger for Implantable Medical Devices

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Solution Overview

Problem

Existing external chargers for implantable medical devices suffer from reduced power efficiency due to eddy currents induced by the magnetic field of the AC charging coil, leading to thermal energy conversion and signal noise, which compromises the charging efficiency and reliability.

Innovation Solution

The external charger design incorporates electronic components arranged along a plane perpendicular to the AC coil, minimizing eddy currents by aligning surfaces parallel to the magnetic field, and utilizes a dual PCB configuration with a vertical PCB extending perpendicular to the charging coil to reduce eddy currents on both components and substrate surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If electronic components are mounted on a conventional PCB parallel to the AC charging coil, then the charging process can be implemented, but eddy currents are induced on the PCB and components causing thermal energy conversion and reduced power efficiency

Engineering Contradiction:

Improvepower efficiencyVSAvoideddy currents

Core Design Contradiction:

Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The patent applies dimensionality change by mounting the PCB perpendicular to the AC charging coil instead of parallel. This orientation change causes the magnetic field lines to pass through the PCB thickness rather than along its surface, dramatically reducing eddy current loops and improving power efficiency by minimizing energy loss to eddy currents.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent employs composite construction by separating the AC charging coil and electronic components onto different planes with perpendicular orientations. This spatial composite arrangement allows the magnetic field to interact minimally with conductive surfaces, reducing eddy current generation while maintaining functional integrity.

Inventive Principle:

Principle #40Composite materials

2Volume of moving object

If electronic components are positioned close to the AC charging coil for compact design, then device size is reduced, but eddy currents increase causing thermal energy conversion and noise

Engineering Contradiction:

Improvecharger sizeVSAvoidthermal energy conversion

Core Design Contradiction:

Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

By transitioning from a parallel to perpendicular mounting configuration, the patent enables compact integration of components near the charging coil while the vertical PCB orientation ensures magnetic field lines penetrate through rather than skim across conductive surfaces. This maintains compact form factor while minimizing eddy current-induced thermal energy conversion.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Loss of energy

If a perpendicular PCB configuration is used to minimize eddy currents, then power efficiency is improved, but device complexity increases due to dual PCB arrangement

Engineering Contradiction:

Improvepower efficiencyVSAvoidPCB configuration

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent segments the charging device into functionally distinct planes: the AC charging coil operates on one plane while electronic components are mounted on a perpendicular PCB. This segmentation allows each component to operate optimally without interfering with the other, minimizing eddy currents while maintaining manageable complexity through clear functional separation.

Inventive Principle:

Principle #1Segmentation

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

This configuration enhances the power efficiency of the charging process by minimizing eddy currents, reducing thermal energy conversion and noise, thereby improving the charging efficiency and reliability of implantable medical devices.

Implementation Method 1

an alternating current (AC) charging coil that supplies energy to a similar charging coil located in or on the implantable pulse generator

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

reduced power efficiency due to eddy currents induced by the magnetic field of the AC charging coil, leading to thermal energy conversion

Methodology Applied

Scientific EffectEddy currents: Eddy Currents

Data Source

PatentUS9333367B2Charger with orthogonal PCB for implantable medical device

Publication Date: 2016.05.10 BOSTON SCI NEUROMODULATION CORP

AI summary

An external charger for an implantable medical device, comprises a housing, an alternating current (AC) coil and substrate contained within the housing, and one or more electronic components mounted to the substrate. The AC coil is configured for wirelessly transmitting magnetic charging energy to the implantable medical device. The AC coil is disposed in a first plane, with the magnetic charging energy having a field directed perpendicular to the first plane. At least a portion of the substrate has a surface extending along a second plane that is substantially perpendicular to the first plane.