Optical Speckle Receiver Aperture Array for Wearable Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical speckle systems are unsuitable for integration into wearable devices due to low light collection and excessive distance between tissue and optical detectors, which limits their application in clinical and home healthcare settings.
Innovation Solution
An optical speckle receiver with an aperture array or lens array is used between the sample and optical detector, allowing for the collection of speckle patterns from multiple discrete sample locations, maintaining an acceptable signal-to-noise ratio and ensuring only deeply interacted light is detected, while minimizing the distance between the sample and sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single mode fiber or aperture array is used to match speckle size to sensor pixel size, then measurement precision is improved, but device complexity increases and the system becomes unsuitable for wearable integration
Solution Approach 1:
The patent divides the optical detection system into multiple discrete apertures arranged in an array, where each aperture captures speckle patterns from different spatial locations. This segmentation allows the system to achieve precise speckle sampling without requiring complex single-mode fiber coupling, thereby reducing device complexity while maintaining measurement precision.
Solution Approach 2:
The patent transitions from one-dimensional speckle detection (single pixel or fiber) to two-dimensional spatial sampling using an aperture array. By distributing multiple apertures across a two-dimensional plane, the system achieves comprehensive speckle pattern capture with simpler individual aperture elements, making the system more suitable for wearable integration.
2Use of energy by moving object
If the distance between tissue and optical detector is increased to capture more light, then light collection is improved, but the device becomes less suitable for wearable applications
Solution Approach 1:
Instead of increasing the distance between the detector and tissue to collect more light, the patent segments the detection area into multiple apertures that are distributed across a planar array. This allows the system to collect sufficient light from multiple spatial locations simultaneously while maintaining a compact form factor suitable for wearable devices.
Solution Approach 2:
The patent combines the light collection function of multiple discrete apertures into a unified detection system. By merging the signals from multiple aperture locations, the system achieves enhanced light collection efficiency equivalent to or greater than a single distant detector, while keeping the overall device compact and wearable-friendly.
3Use of energy by moving object
If multiple uncorrelated speckle patterns are added on an intensity basis to increase signal, then light collection is improved, but speckle contrast is reduced by 1/sqrt(M)
Solution Approach 1:
The patent inverts the conventional approach of adding speckle patterns on an intensity basis. Instead, it captures multiple speckle patterns simultaneously through spatially separated apertures and combines them in a way that preserves their complex amplitude relationships, thereby maintaining speckle contrast while achieving signal enhancement through increased photon collection.
Solution Approach 2:
The patent transitions from temporal addition of speckle patterns (which reduces contrast) to spatial parallel capture using an aperture array. By distributing apertures across different spatial locations that sample independent speckle realizations, the system maintains high contrast while collecting more light, effectively moving the combination operation into the spatial domain rather than the temporal intensity domain.
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
This configuration enhances the signal-to-noise ratio and allows for more robust and compact optical speckle data collection, enabling effective monitoring of physiological parameters in wearable devices without reducing speckle contrast, even when using multiple apertures or lenses.
Implementation Method 1
the aperture array and/or lens array respectively comprise a plurality of apertures or lenses and is located between, or in-between, the surface or sample and the optical detector such that the received speckle pattern is obtained from multiple discrete sample locations
Implementation Method 2
an optical detector and an aperture array or a lens array
Implementation Method 3
Speckle fluctuations due to the interaction of coherent light with dynamic scatterers (for example red blood cells)
Data Source
AI summary
An optical speckle receiver for receiving a speckle signal from a sample, the optical speckle receiver comprising an optical detector and an aperture and/or lens array. The aperture and array respectively comprise a plurality of apertures or lenses and is located between the sample and the optical detector such that the received speckle pattern is obtained from multiple discrete sample locations.