Multichannel Neuromodulation System with Analog Front-End and Neural Classifier

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Solution Overview

Problem

Existing closed-loop neuromodulation devices, such as system-on-chip (SoC) devices with integrated machine learning, are limited by low channel count and poor generalizability, which restricts their therapeutic efficacy and application scope.

Innovation Solution

The proposed solution involves an analog front-end device with a switch matrix and dual multiplexing choppers for dynamic channel selection, along with a filter and feature extraction engine that includes a time-division multiplexed (TDM) finite impulse response (FIR) filter and a feature extraction engine (FEE) capable of extracting phase synchrony, frequency, and temporal features. These features are then processed by a tree-structured hierarchical neural network classifier for disease symptom detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If existing SoC devices with integrated machine learning are used, then device complexity is reduced, but channel count is limited to 8-32 channels

Engineering Contradiction:
Improvedevice complexityVSAvoidchannel count
Core Design Contradiction:
Device complexityVSQuantity of substance

Solution Approach 1:

The system segments the processing architecture into distinct functional blocks: a high-channel-count analog front-end (supporting 128-256 channels) and a separate machine learning processing unit. This segmentation allows the front-end to handle more channels while the ML unit processes features independently, resolving the contradiction between device complexity and channel count.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from processing raw multi-channel signals to extracting and processing neural biomarkers as features. This dimensional transformation from time-domain signals to feature-space representations enables handling of higher channel counts by reducing the data dimensionality that requires complex processing.

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

2Adaptability or versatility

If existing SoC devices with integrated machine learning are used, then integration is improved, but generalizability is poor

Engineering Contradiction:
ImprovegeneralizabilityVSAvoidintegration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system extracts multiple types of neural biomarkers (spectral, temporal, spatial, and cross-frequency coupling features) from the same multi-channel neural signals, enabling the device to address various neurological conditions and applications. This multi-functionality approach improves generalizability without proportionally increasing integration complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If high channel count is implemented, then measurement precision is improved, but power consumption increases

Engineering Contradiction:
Improvemeasurement precisionVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system extracts and processes only the most relevant neural biomarkers and features from the multi-channel signals using machine learning algorithms. By taking out and processing only essential features rather than all raw signal data, the system maintains measurement precision while significantly reducing the computational power required.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system implements partial processing by focusing computational resources on extracting key neural biomarkers rather than processing all signal parameters in full detail. This partial action approach maintains sufficient measurement precision for clinical applications while reducing overall power consumption.

Inventive Principle:
Principle #16Partial or excessive action

4Adaptability or versatility

If high channel count is implemented, then application scope is expanded, but chip surface area increases

Engineering Contradiction:
Improveapplication scopeVSAvoidchip surface area
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent merges multiple signal processing functions (filtering, feature extraction, biomarker computation) into a integrated machine learning processing unit that handles data from all channels. This consolidation allows high channel count implementation without proportionally increasing chip surface area, as shared processing resources serve multiple functions.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentUS20250160725A1A multichannel versatile brain activity classification and closed loop neuromodulation system, device and method using a highly multiplexed mixed-signal front-end
Publication Date: 2025.05.22 ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL)
  • US20250160725A1 patent drawing
  • US20250160725A1 patent drawing
  • US20250160725A1 patent drawing

AI summary

A closed-loop neuromodulation system, including an electrode array that is implantable to a brain of a subject, analog front-end device (AFD) for selectively selecting and reading a plurality of channels from electrode array, a finite impulse response (FIR) filter for selectively filtering signals from the AFD, a feature extraction engine (FEE) operatively connected to the FIR filter, configured to selectively extract features from signals provided by the FIR filter, a tree-structured hierarchical neural network classifier for detecting disease symptoms, and a multi-channel stimulator having high-voltage (HV) drivers operatively connectable to the electrode array.