NV Center Diamond Magnetometer for Cardiac Field Detection

Solution Overview

Problem

Current magnetocardiography systems, such as those using superconducting quantum interference devices (SQUID), require expensive and continuous liquid helium cooling, operate in ultra-low temperatures, and cannot be in contact with the skin for cardiac magnetic field measurement, leading to high maintenance costs and reduced accuracy.

Innovation Solution

A magnetometer based on nitrogen-vacancy (NV) centers in diamond, which includes an array probe with a porous rotary fiber coupling apparatus, fiber laser source, microwave source, and special diamond with NV centers, allowing for room temperature operation and contact measurement with enhanced sensitivity and adjustability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If SQUID system is used for cardiac magnetic field measurement, then measurement sensitivity is improved (reaching 10 fT), but operation and maintenance costs increase due to continuous liquid helium replenishment

Engineering Contradiction:

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces expensive liquid helium with a solid-state NV center system that uses inexpensive diamond crystals. The NV centers can be replenished or replaced without requiring costly cryogenic fluids, significantly reducing operational expenses while maintaining measurement sensitivity.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent substitutes the mechanical cryogenic cooling system (Dewar bottle with liquid helium) with a room-temperature solid-state quantum system. This eliminates the need for complex cooling infrastructure and continuous fluid replenishment, reducing both costs and system complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If SQUID system operates in ultra-low temperature environment, then measurement sensitivity is improved, but contact measurement with skin is prevented

Engineering Contradiction:

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent changes the operating temperature parameter from ultra-low temperature (liquid helium environment) to room temperature. This parameter change enables the probe to be placed in direct contact with the skin for measurement while maintaining quantum coherence and measurement sensitivity through the NV center system.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If SQUID system uses fixed structure, then measurement sensitivity is maintained, but adaptability for different measurement configurations is reduced

Engineering Contradiction:

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent divides the measurement system into modular components including an array of NV center probes that can be independently configured and positioned. This segmentation allows flexible adaptation to different measurement geometries and applications while maintaining the high sensitivity provided by individual NV center units.

Inventive Principle:

Principle #1Segmentation

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 NV center-based magnetometer achieves high sensitivity and low maintenance costs, enabling precise and efficient cardiac magnetic field measurement with reduced operational expenses and improved accuracy due to room temperature operation and contact measurement capabilities.

Implementation Method 1

The ring-shaped antenna is connected to the microwave source to evenly radiate electromagnetic waves, so that the Optical Detected Magnetic Resonance (ODMR) signal is performed together with the function of magnetic field

Methodology Applied

Scientific EffectOptical detected magnetic resonance (ODMR):

Implementation Method 2

The special diamond emits 600 nm-800 nm fluorescence under the irradiation of 532 nm laser

Methodology Applied

Scientific EffectFluorescence: Fluorescence

Implementation Method 3

The ring-shaped antenna is connected to the microwave source to evenly radiate electromagnetic waves

Methodology Applied

Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Data Source

PatentUS11678826B2Magnetometer used for cardiac magnetic field measurement and based on nitrogen-vacancy (NV) centers in diamond, and cardiac magnetic field measurement system

Publication Date: 2023.06.20

AI summary

The present disclosure provides a cuboid magnetometer with high fluorescence collection efficiency, used for cardiac magnetic field measurement, and based on nitrogen-vacancy (NV) centers in diamond, and a cardiac magnetic field measurement system. The cardiac magnetic field measurement system includes a magnetic shielding chamber, a non-magnetic bed, an array probe for cardiac magnetic field measurement, a three-axis displacement platform, a high-speed data collection card, a fiber laser source, a microwave source, and a computer. The array probe for cardiac magnetic field measurement includes a non-magnetic shell, a stepping motor, a porous rotary fiber coupling apparatus, a fiber bundle set, a special photodetector (PD) set, a filter set, a ring-shaped antenna, and special diamond.