Differential Voltage Supply for Neural Recorders

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Solution Overview

Problem

Neural activity recorders face a reduced common-mode rejection ratio due to impedance mismatch between positive and negative input terminals of low-noise amplifiers, which affects signal measurement accuracy.

Innovation Solution

A differential voltage supplying apparatus that includes a differential voltage generator and a common-mode signal combiner, which generates and combines signals to compensate for impedance differences, improving the common-mode rejection ratio by at least 40 decibels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a neural activity recorder uses multiple detection electrodes connected to low-noise amplifiers with a single reference electrode, then the number of measurement channels increases, but impedance mismatch between positive and negative input terminals reduces the common-mode rejection ratio

Engineering Contradiction:

Improvenumber of measurement channelsVSAvoidcommon-mode rejection ratio

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent introduces a reference electrode as an intermediary element that is shared across all measurement channels. Instead of having separate reference electrodes for each channel, the single reference electrode serves as a common mediator for all detection electrodes, thereby maintaining impedance balance and preserving common-mode rejection ratio while enabling multi-channel measurements.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The reference electrode performs multiple functions simultaneously: it serves as the negative input terminal for all low-noise amplifiers across different channels, provides a common reference potential for all measurements, and maintains impedance balance throughout the system. This multi-functional design allows the system to achieve both high channel count and maintained measurement precision.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Device complexity

If the impedance of positive and negative input terminals of low-noise amplifiers differ, then device complexity is reduced, but signal measurement accuracy deteriorates due to reduced common-mode rejection ratio

Engineering Contradiction:

Improveamplifier terminal impedance matchingVSAvoidsignal measurement accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent establishes equipotential conditions by connecting all negative input terminals of the low-noise amplifiers to a common reference electrode. This creates an equipotential reference level across all channels, ensuring that despite any impedance differences in the amplifiers, the common-mode voltage remains stable and the common-mode rejection ratio is preserved, thereby maintaining signal measurement accuracy without requiring complex impedance matching circuits.

Inventive Principle:

Principle #12Equipotentiality

Data Source

PatentUS10263580B2Power supplying apparatus for neural activity recorder reducing common-mode signal applied to electrodes connected to the neural activity recorder

Publication Date: 2019.04.16 DAEGU GYEONGBUK INSTITUTE OF SCIENCE AND TECHNOLOGY

AI summary

Disclosed is a differential voltage supplying apparatus configured to supply, to a neural activity recorder, an input signal generated by combining, with a direct current (DC) power supply, a common-mode signal determined from a voltage applied to a detection electrode and a reference electrode connected to the neural activity recorder, and improve a common-mode rejection ratio of the neural activity recorder and generate a DC power supply.