Stretchable Sensor Assembly With Wave-Shaped PCB for Finger Alignment
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Solution Overview
Problem
Existing finger pulse oximeter sensors face misalignment issues due to varying finger diameters, leading to inaccurate oxygen saturation measurements when the emitter and detector become misaligned with larger or smaller fingers, necessitating multiple sensor sizes to accommodate different patient sizes, which increases cost and complexity.
Innovation Solution
A stretchable sensor assembly using a wave-shaped flexible printed circuit board (PCB) with conductive traces and an elastic sleeve to maintain alignment of the emitter and detector across varying finger sizes, allowing a single size to fit a range of targets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a fixed-size sensor assembly is used, then the structure is simple and cost-effective, but the emitter and detector become misaligned when fitted to fingers of different sizes
Solution Approach 1:
The sensor assembly incorporates a stretchable band that can dynamically change its circumference to accommodate different finger sizes. The band transitions from a relaxed state for smaller fingers to a stretched state for larger fingers, maintaining proper emitter-detector alignment across varying target dimensions without requiring multiple fixed-size sensor designs.
Solution Approach 2:
The invention changes the physical parameter of the sensor assembly's circumference by utilizing the elastic properties of the stretchable band. The band's ability to elongate allows the same sensor assembly to fit different finger sizes while maintaining the critical alignment parameter between emitter and detector through controlled deformation of the band structure.
2Manufacturing precision
If multiple sensor sizes are produced to accommodate different finger sizes, then alignment is maintained across all sizes, but device complexity and cost increase
Solution Approach 1:
The stretchable sensor assembly achieves universality by designing a single sensor unit that can function on fingers of various sizes. The stretchable band allows one sensor assembly to serve multiple size categories, eliminating the need to manufacture and stock multiple fixed-size variants while maintaining alignment precision through the band's adaptive stretching capability.
3Adaptability or versatility
If the sensor assembly is made stretchable to fit different finger sizes, then a single design fits all, but the flexibility and stability of electrical connections may be compromised
Solution Approach 1:
The invention employs a flexible printed circuit board (FPCB) to maintain reliable electrical connections in the stretchable sensor assembly. The FPCB can withstand repeated stretching and returning to its original shape without degrading the electrical connections between the emitter, detector, and control circuitry, thus preserving connection stability while enabling adaptability to different finger sizes.
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 stretchable sensor assembly ensures accurate oxygen saturation measurements by maintaining alignment of the emitter and detector regardless of finger size, reducing the need for multiple sensor sizes and minimizing tangling or snagging.
Implementation Method 1
a wave-shaped flexible printed circuit board (PCB) disposed between the emitter and the detector
Data Source
AI summary
Systems are provided for a device comprising an emitter, a detector, a power/signal cable directly connected to one of the detector or the emitter, and a wave-shaped flexible printed circuit board (PCB) disposed between the emitter and the detector, wherein the wave-shaped flexible PCB includes a first plurality of conductive traces. The device may further comprise an elastic cover which makes the device a stretchable sensor assembly.