Sensor Module Intermittent Near-Infrared Emission for Low Power
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Solution Overview
Problem
Existing sensor modules for biological information, such as blood component measurement, face challenges in reducing power consumption while maintaining measurement cycles, as decreasing CPU clock frequency can lead to overlapping processes, potentially causing operational failures.
Innovation Solution
A sensor module design with a light emitter using multiple near-infrared light emitting elements of different central wavelengths, emitting light intermittently in sets with varying non-light-emission periods, allowing for a longer second non-light-emission period for processing, ensuring completion of biological information estimation without process overlap, even at reduced CPU clock frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the clock frequency of the CPU is decreased to reduce power consumption, then power consumption is reduced, but the processing time increases causing measurement processes to overlap with light emission or detection processes
Solution Approach 1:
The patent applies dynamics by making the light emission timing adaptable to the processing speed. The light emitter is configured to emit light at timings that accommodate the CPU's processing capabilities, allowing the system to dynamically adjust its operation mode based on whether it is in a measurement cycle or a non-measurement cycle, thus resolving the contradiction between low-frequency operation and process overlap
Solution Approach 2:
The patent implements periodic action by dividing operation into distinct measurement cycles and non-measurement cycles. During measurement cycles, the CPU performs biological information estimation at reduced frequency, while during non-measurement cycles, the system prepares for the next measurement. This periodic structure prevents process overlap while maintaining reduced power consumption
2Use of energy by moving object
If the clock frequency of the CPU is decreased to reduce power consumption, then power consumption is reduced, but the processing speed decreases causing incomplete biological information estimation
Solution Approach 1:
The patent applies preliminary action by performing light emission and signal reception before the CPU completes its biological information estimation processing. The light emitter emits light and the light receiver detects signals in advance, so that when the CPU finishes processing at its reduced clock frequency, the data is already available, thus maintaining processing completeness without requiring high CPU frequency
Solution Approach 2:
The system dynamically coordinates the timing of light emission, signal detection, and CPU processing. The measurement cycle duration is adjusted based on the CPU's processing speed, allowing the system to maintain accurate biological information estimation even at lower clock frequencies by extending the time available for processing
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 design effectively reduces power consumption by allowing the CPU to operate at lower frequencies without compromising measurement cycles, ensuring accurate and uninterrupted biological information estimation, including blood hemoglobin and oxygen level measurements.
Implementation Method 1
a plurality of first light emitting elements disposed spaced apart from each other and configured to emit near-infrared light beams having central wavelengths different from each other
Implementation Method 2
a light receiving element that is disposed to receive the near-infrared light beams emitted from the plurality of first light emitting elements and that is sensitive to the near-infrared light beams
Data Source
AI summary
A sensor module includes a light emitter that emits light beams including near-infrared light beams towards a subject; a light receiver that receives light beams having passed through the subject; and a controller that estimates biological information based on signals output from the light receiver. The light emitter includes a plurality of light emitting elements that emit near-infrared light beams having central wavelengths different from each other. The light emitter produces sets of light emissions by causing the plurality of light emitting elements to sequentially and intermittently emit the near-infrared light beams. In given two consecutive sets of light emissions produced by the light emitter, a second non-light-emission period of time T4 is longer than a first non-light-emission period of time T2. The controller estimates the biological information in a processing period of time T41 that is set in correspondence with the second non-light-emission period of time T4.