Photoacoustic Light Guide With EMI Shielding for Low-Noise Detection
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Solution Overview
Problem
Existing photoacoustic devices face challenges with low signal-to-noise ratio due to electromagnetic interference (EMI) from light source system circuitry, which affects the sensitivity and accuracy of receiver signals.
Innovation Solution
Incorporating an electromagnetic interference (EMI)-reducing layer and a light guide system to shield the receiver system from EMI and noise, while using a light source system configured to emit light through an opening or transparent portion of the EMI-reducing layer, and employing a light-directing element to direct light to a light pipe.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If light source system circuitry is placed close to receiver system circuitry to reduce device size, then device compactness is improved, but electromagnetic interference increases and signal-to-noise ratio deteriorates
Solution Approach 1:
An EMI-reducing layer is introduced as an intermediary component between the light source system circuitry and receiver system circuitry. This layer acts as a mediator that allows the circuits to be positioned close together for compactness while blocking electromagnetic interference, thus maintaining high signal-to-noise ratio.
Solution Approach 2:
The harmful electromagnetic interference is extracted and blocked by the EMI-reducing layer, allowing the light source circuitry to be separated from the receiver circuitry in terms of electromagnetic influence while maintaining physical proximity for compact device design.
2Measurement precision
If EMI-reducing layer is added to shield receiver system from interference, then signal-to-noise ratio is improved, but device complexity increases
Solution Approach 1:
The EMI-reducing layer is implemented as a thin film or shell structure that provides electromagnetic shielding with minimal added complexity. This thin-film approach allows EMI protection to be integrated into existing device layers without significantly increasing overall structural complexity.
3Object-affected harmful factors
If light is emitted through EMI-reducing layer to maintain shielding, then EMI protection is improved, but light transmission may be blocked reducing illumination intensity
Solution Approach 1:
The EMI-reducing layer is designed with different properties in different regions: it provides EMI shielding where needed while maintaining optical transparency in the light emission path. This local differentiation allows the same layer to simultaneously block EMI and transmit light effectively.
Solution Approach 2:
The EMI-reducing layer utilizes composite material structures that combine electromagnetic shielding properties with optical transparency. These composite materials allow the layer to block EMI while permitting light transmission, resolving the contradiction between shielding and illumination.
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
Enhances the sensitivity of the device to photoacoustic waves, reduces noise interference, and improves the signal-to-noise ratio, enabling accurate detection of acoustic waves for applications like blood pressure monitoring.
Implementation Method 1
a first EMI-reducing layer may reduce a level of EMI emitted by the light source system circuitry that is received by the receiver system circuitry
Implementation Method 2
the light source system may be configured to transmit light from the light-emitting component through the first EMI-reducing layer to a first platen area
Implementation Method 3
the receiver system may be configured to detect acoustic waves corresponding to a photoacoustic response of a target object in contact with the first platen area to light emitted by the light source system
Data Source
AI summary
An apparatus may include a platen, an electromagnetic interference (EMI)-reducing system including a first EMI-reducing layer, a light source system and a receiver system. The light source system may include a light-emitting component, light source system circuitry and a light guide system and may be configured to emit light through the first EMI-reducing layer to a first platen area via a light pipe between the first EMI-reducing layer and the platen. The light guide system may include a light-directing element for directing light from the first EMI-reducing layer to the light pipe. The receiver system may be configured to detect acoustic waves corresponding to a photoacoustic response of a target object in contact with the first platen area to light emitted by the light source system. The first EMI-reducing layer may reduce a level of EMI emitted by the light source system circuitry that is received by receiver system circuitry.