Dipole Antenna on Ceramic Case for Implantable Microdevices

Solution Overview

Problem

Existing implantable microstimulators and microsensors face challenges with high tissue detuning and space constraints when using telemetry systems, particularly at higher frequencies like 402 to 405 MHz, due to limitations in existing antenna designs such as monopole and dipole antennas.

Innovation Solution

A dipole antenna is formed on the case of an implantable microdevice using two cylindrical sections separated by an insulating material, with a tuning circuit comprising capacitors and/or inductors to achieve resonance and increase effective antenna impedance, allowing for efficient operation in the 402 to 405 MHz frequency range without occupying internal space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a monopole or dipole antenna is used in existing microstimulators, then signal transmission is enabled, but tissue detuning occurs and internal space is consumed

Engineering Contradiction:

Improvesignal transmission reliabilityVSAvoidtissue detuning

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The antenna is extracted from the internal space of the microstimulator and relocated to the external ceramic case. This extraction eliminates the space conflict and allows the antenna to be positioned where it can operate without being detuned by surrounding tissue, while the ceramic case provides a stable, non-conductive mounting surface.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The antenna design transitions from a three-dimensional internal structure to a two-dimensional planar pattern formed on the ceramic case surface. This dimensional change allows the antenna to maintain its electrical characteristics while occupying minimal space within the device constraints.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If a monopole or dipole antenna is used in existing microstimulators, then signal transmission is enabled, but internal space is consumed

Engineering Contradiction:

Improvesignal transmission reliabilityVSAvoidinternal space consumption

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The antenna is extracted from the internal space of the microstimulator and relocated to the external ceramic case. This extraction eliminates the space conflict and allows the antenna to be positioned where it can operate without being detuned by surrounding tissue, while the ceramic case provides a stable, non-conductive mounting surface.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The antenna design transitions from a three-dimensional internal structure to a two-dimensional planar pattern formed on the ceramic case surface. This dimensional change allows the antenna to maintain its electrical characteristics while occupying minimal space within the device constraints.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Productivity

If higher frequencies like 402 to 405 MHz are used, then telemetry performance is improved, but tissue detuning increases

Engineering Contradiction:

Improvetelemetry performanceVSAvoidtissue detuning

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The antenna is extracted from the internal space of the microstimulator and relocated to the external ceramic case. This extraction eliminates the space conflict and allows the antenna to be positioned where it can operate without being detuned by surrounding tissue, while the ceramic case provides a stable, non-conductive mounting surface.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The antenna design incorporates specific geometric parameters and tuning circuits optimized for operation at 402 to 405 MHz frequencies. By carefully controlling the antenna dimensions, conductor material properties, and surrounding dielectric constants, the system achieves resonance at these higher frequencies while minimizing tissue detuning effects.

Inventive Principle:

Principle #35Parameter changes

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 dipole antenna provides effective signal transmission and reception with reduced tissue detuning and space utilization, enabling reliable operation in the targeted frequency range while maintaining the internal space for circuit components.

Implementation Method 1

a tuning circuit comprising capacitors and/or inductors to achieve resonance and increase effective antenna impedance

Methodology Applied

Scientific EffectResonance: Resonance

Implementation Method 2

two cylindrical sections separated by an insulating material

Methodology Applied

Scientific EffectElectrical insulation: Dielectric

Data Source

PatentUS7908014B2Antenna on ceramic case

Publication Date: 2011.03.15 ALFRED E MANN FOUND FOR SCI RES

AI summary

The invention is an antenna for use with an implantable microdevice, such as a microstimulator or microsensor, having a dipole antenna that is formed by ceramic processes on the inner or outer surface of the ceramic case of the microdevice. The antenna receives data transmitted from an external device, and transmits data to an external device. A dipole antenna may be formed from two radiating elements separated by an insulating material. A tuning circuit comprising capacitors and/or inductors is used to obtain resonance in the dipole antenna. In a preferred embodiment, the antenna is formed of a biocompatible material by applying a metal-containing paste to the ceramic case of the microdevice and thermally processing it.