Circular TMS Coil with Protruding Return Elements for Deep Brain Stimulation

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Solution Overview

Problem

Current transcranial magnetic stimulation (TMS) coils have limited efficacy in targeting deep neuronal structures due to high decay of magnetic and electric fields with distance, leading to inefficient stimulation of deeper brain regions and increased risk of seizures and tissue damage.

Innovation Solution

Design of circular TMS coils with optimized base and return portion configurations, including specific arrangements of stimulating and return elements, to enhance depth penetration and absolute electric field intensity while minimizing side effects, ensuring efficient neuronal stimulation across various brain regions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high current intensity is used to stimulate deep neuronal structures, then the efficacy of deep brain stimulation is improved, but the risk for seizures and physiological damage to tissue increases

Engineering Contradiction:
Improvedeep brain stimulation efficacyVSAvoidseizure risk and tissue damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The coil design creates different current density distributions in different regions. The base portion generates high current density for deep brain stimulation, while the return portions are configured to minimize current flow through superficial brain regions, creating localized quality differences that enable deep stimulation without superficial overheating or seizure risk

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The coil is divided into functionally distinct segments: a base portion for generating the primary stimulating field and return portions for completing the circuit while minimizing unwanted stimulation. This segmentation allows independent optimization of each portion's characteristics to achieve deep penetration while controlling side effects

Inventive Principle:
Principle #1Segmentation

2Reliability

If conventional TMS coil design is used, then the construction is simple, but the ability to target deep neuronal structures with minimal effect on other brain regions is insufficient

Engineering Contradiction:
Improvetargeting precision for deep brain regionsVSAvoidcoil structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The coil is divided into functionally distinct segments: a base portion for generating the primary stimulating field and return portions for completing the circuit while minimizing unwanted stimulation. This segmentation allows independent optimization of each portion's characteristics to achieve deep penetration while controlling side effects

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coil design transitions from conventional planar configurations to a three-dimensional structure with the base portion and multiple return portions arranged in specific spatial configurations. This dimensional change enables precise control of current flow paths to target deep brain regions while avoiding superficial structures

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Length of moving object

If the coil is designed to encircle body parts for deep stimulation, then the depth penetration is improved, but the coil size and complexity increase

Engineering Contradiction:
Improvedepth penetration capabilityVSAvoidcoil configuration complexity
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The coil is divided into functionally distinct segments: a base portion for generating the primary stimulating field and return portions for completing the circuit while minimizing unwanted stimulation. This segmentation allows independent optimization of each portion's characteristics to achieve deep penetration while controlling side effects

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The base portion is configured in a circular or oval shape that can encircle body parts such as the head or limbs. This curved geometry enables the coil to conform to anatomical structures and achieve deep penetration while maintaining a compact form factor

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 optimized coil design achieves targeted deep brain stimulation with reduced side effects, inducing the necessary electric field intensity for neuronal activation in the majority of the population, as demonstrated by improved clinical trial results in treating conditions like Alzheimer's and Parkinson's disease.

Implementation Method 1

passing high currents by a stimulator through an electromagnetic coil externally placed upon the patient (for example, placed on the scalp for brain treatment), inducing electrical currents in the underlying tissue, thereby producing a localized axonal depolarization

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3733241B1Coil for magnetic stimulation of a body part
Publication Date: 2024.10.09 BRAINSWAY
  • EP3733241B1 patent drawingFigure 1
  • EP3733241B1 patent drawingFigure 2A~2B
  • EP3733241B1 patent drawingFigure 2C~3A

AI summary

A coil for magnetic stimulation of a body part, the coil (10) comprising, a base portion (12) including multiple adjacent stimulating elements (20), said base portion (12) configured to encircle at least a portion of a first section of a body part and to provide electrical flow in a substantially clockwise or counter-clockwise path; and a protruding return portion (32) including multiple adjacent protruding return elements (40), said protruding return portion (32) configured to encircle and protrude from the body part, and to provide electrical flow in a continuation of the clockwise or counter-clockwise circular path of said base portion (12), wherein all of said multiple stimulating elements of said base portion are configured to contact the body part and wherein all of said multiple protruding return elements are configured to protrude from the body part.