Implantable Device Power Transfer via Anticipated Square Wave Current

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Solution Overview

Problem

Implanted medical devices face insulation breaches and corrosion, leading to unregulated voltage exposure and device failure, with size constraints limiting the use of discrete components for stable power supply.

Innovation Solution

A system with a first and second unit implanted in a patient, connected by a cable, where the first unit supplies a square current waveform with intermittent polarity changes, and a processor anticipates the second unit's actions to adjust the current output, using a push-pull circuit for current limitation and series capacitors to balance charge, ensuring minimal current flow through biological tissue.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If discrete components are used for stable power supply in implanted devices, then power supply stability is improved, but device size increases

Engineering Contradiction:
Improvepower supply stabilityVSAvoiddevice size
Core Design Contradiction:
Stability of the object's compositionVSVolume of moving object

Solution Approach 1:

The patent merges the power supply circuitry with the signal processing circuitry into a single integrated circuit. This integration eliminates the need for separate discrete power supply components, thereby maintaining power supply stability while reducing the overall device size. The unified circuit design allows for compact implantable devices without compromising electrical stability.

Inventive Principle:
Principle #5Merging (Combining)

2Use of energy by moving object

If continuous current is supplied to ensure adequate power delivery, then power availability is improved, but risk of unregulated voltage exposure increases

Engineering Contradiction:
Improvepower availabilityVSAvoidunregulated voltage exposure
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent implements periodic polarity reversal in the current supply waveform. The current switches between positive and negative polarities in a controlled manner, which prevents accumulation of charge and eliminates the risk of unregulated voltage exposure. This periodic action maintains adequate power delivery while ensuring safety through balanced charge transfer over time.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent incorporates monitoring circuitry that detects insulation breaches and corrosion conditions in real-time. When abnormal conditions are detected, the system automatically adjusts or terminates current flow to prevent harmful effects. This feedback mechanism ensures that power is delivered adequately during normal operation while preventing unregulated voltage exposure when faults occur.

Inventive Principle:
Principle #23Feedback

3Object-affected harmful factors

If polarity of current is reversed frequently to prevent charge imbalance, then safety is improved, but power delivery stability deteriorates

Engineering Contradiction:
Improvecharge imbalanceVSAvoidpower delivery stability
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent employs controlled periodic polarity reversal at optimized intervals that balance charge balance requirements with power delivery stability. By timing the polarity switches to occur during periods of minimal power demand or when charge accumulation is most critical, the system maintains stable power delivery while preventing charge imbalance. The periodic action is synchronized with the device's operational cycle to minimize disruption to power delivery.

Inventive Principle:
Principle #19Periodic action

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 system reduces the risk of unregulated current flow and device failure by anticipating and adjusting power delivery, minimizing size constraints through efficient use of integrated circuitry and eliminating net DC, thus enhancing safety and longevity of implanted devices.

Implementation Method 1

a current supply unit that supplies a selected current output to the second unit via the cable, wherein the current output is a square current waveform having intermittent transitions of polarity

Methodology Applied
Scientific EffectSquare waveform current:

Implementation Method 2

The second unit may comprise a rectifier to rectify the current output received via the cable to power the second unit

Methodology Applied
Scientific EffectRectification: Diode

Implementation Method 3

The stimulus controller may comprise means for current limitation such that a current to the one or more electrodes is negligible unless the received control information specifies stimulation by the one or more electrodes. The means for current limitation may comprise a push-pull circuit.

Methodology Applied
Scientific EffectCurrent limitation: Electrical Resistance

Implementation Method 4

The system may comprise means for reducing a charge imbalance between the first unit and the second unit including for example at least one capacitor connected in series between the current supply unit and the cable

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP2485801B1Method of power and data transfer in implantable electronic devices
Publication Date: 2018.05.02 NEWSOUTH INNOVATIONS PTY LTD
  • EP2485801B1 patent drawingFigure 1~3
  • EP2485801B1 patent drawingFigure 4

AI summary

A system for transferring data and power between electronic devices implanted in a patient is described. The system comprises a first unit and a second unit that in use are both implanted in the patient and a cable connecting the first unit and the second unit. The first unit comprises a current supply unit that supplies a selected current output to the second unit via the cable and a processor configured to anticipate an action to be performed by the second unit and to select the current output dependent on the anticipated action.