Enhanced Active Electrode with Adaptive Chopper Modulation for Improved Signal Quality

Publication ID: 24-11857328_0001_PTD
Published: November 07, 2025
Category:Direct Improvements & Enhancements

Legal Citation

pr1or.art Inc., “Enhanced Active Electrode with Adaptive Chopper Modulation for Improved Signal Quality,” Published Technical Disclosure No. 24-11857328_0001_PTD, Published November 07, 2025, available at https://archive.pr1or.art/24-11857328_0001_PTD
This technical disclosure describes improvements that would be readily apparent to a Person Having Ordinary Skill In The Art (PHOSITA) when considered in combination with the foundational architecture disclosed in U.S. Patent No. 11,857,328.

Summary of the Inventive Concept

An improved active electrode system for sensing electric potential differences, featuring adaptive chopper modulation to minimize flicker noise and optimize signal quality.

Background and Problem Solved

The original patent disclosed an active electrode having a closed-loop unit-gain amplifier with chopper modulation. However, the modulation frequency was fixed, which limited the system's ability to adapt to varying noise conditions. The new inventive concept addresses this limitation by introducing dynamically adjustable modulation frequencies to optimize signal quality and minimize noise.

Detailed Description of the Inventive Concept

The enhanced active electrode system comprises an electrode for sensing bio-potentials, a shield placed adjacent to and electrically insulated from the electrode, and a closed-loop unit-gain amplifier with adaptive chopper modulation. The amplifier operates at a frequency higher than the corner frequency, minimizing flicker noise and improving signal quality. The modulation frequency is dynamically adjustable to optimize signal quality and minimize noise. The system also includes a method for reducing noise in the electric field sensor by applying a modulation signal to the bio-potential signal at a frequency greater than the corner frequency, thereby shifting the noise spectrum and reducing low-frequency flicker noise.

Novelty and Inventive Step

The new inventive concept introduces adaptive chopper modulation, which allows the system to dynamically adjust the modulation frequency to optimize signal quality and minimize noise. This is a significant improvement over the original patent's fixed modulation frequency, as it enables the system to adapt to varying noise conditions and provides better signal quality.

Alternative Embodiments and Variations

Alternative embodiments of the inventive concept could include using different types of amplifiers or modulation techniques, such as pulse-width modulation or amplitude-shift keying. Additionally, the system could be implemented using different materials or fabrication techniques to improve its performance and reliability.

Potential Commercial Applications and Market

The enhanced active electrode system has potential commercial applications in various industries, including medical devices, biomedical research, and industrial sensing. The system's improved signal quality and noise reduction capabilities make it an attractive solution for applications requiring high-fidelity sensing of electric potential differences.

Field of Art

Biomedical signal processing and electrical sensing systems, specifically focused on low-noise bio-potential measurement techniques using active electrodes and noise reduction strategies

Person of Ordinary Skill (PHOSITA) Profile

An electrical engineer with expertise in analog circuit design, signal processing, noise reduction techniques, and biomedical instrumentation, typically holding a master's degree or equivalent professional experience in electrical engineering or biomedical engineering

Obviousness Rationale

A PHOSITA would recognize that the PTD's adaptive chopper modulation represents an incremental improvement to the source patent's fixed-frequency noise reduction technique. The core concept of frequency-based noise mitigation remains consistent, with the PTD merely extending the original approach by introducing dynamic frequency adjustment to optimize signal quality across varying noise conditions.

Obvious Combinations & Variations

Source Patent Element
Fixed-frequency chopper modulation to shift noise spectrum
PTD Variation
Dynamically adjustable modulation frequency that can adapt to different noise environments
Obviousness Reasoning
A PHOSITA would find it obvious to implement variable frequency modulation as a predictable optimization of the known fixed-frequency technique, representing a standard design improvement in signal processing systems
Source Patent Element
Unit-gain amplifier with chopper modulation
PTD Variation
Closed-loop unit-gain amplifier with adaptive modulation frequency selection
Obviousness Reasoning
Modifying amplifier control loops to provide dynamic frequency adaptation is a known technique in analog circuit design, representing a straightforward engineering solution to improve noise performance
Source Patent Element
Electric potential difference sensing with shielded electrodes
PTD Variation
Enhanced shield design with actively driven buffered output signal
Obviousness Reasoning
Implementing active shielding techniques is a standard approach in reducing capacitive noise, and a PHOSITA would recognize multiple equivalent methods of implementing such noise reduction strategies
Source Patent Element
Bio-potential signal processing with frequency-dependent noise characteristics
PTD Variation
Frequency-dependent gain correction applied to input signal
Obviousness Reasoning
Applying gain correction based on frequency-dependent noise is a well-known signal processing technique, representing a predictable solution to managing signal quality in electrical sensing systems
35 U.S.C. § 103 Summary: Based on the teachings of US Patent 11857328, the present publication demonstrates that the claimed variations in active electrode design and signal processing would have been obvious to a person having ordinary skill in the art at the time of invention, as the technical modifications represent predictable extensions of known noise reduction and signal processing techniques in biomedical sensing systems.

Original Patent Information

Patent NumberUS 11,857,328
TitleActive electrode having a closed-loop unit-gain amplifier with chopper modulation
Assignee(s)T&W Engineering A/S