PPG Sensor Pixel Array Power Segmentation

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Solution Overview

Problem

Photoplethysmogram (PPG) sensors face inefficiencies in power consumption due to the need to continuously collect and process light data from all pixels, leading to unnecessary power usage on non-effective areas, which affects battery life in wearable devices.

Innovation Solution

A PPG sensor system that includes a pixel array, a pixel sampler, an effective area determiner, a power controller, and a PPG data generator, which identifies and cuts off power to non-effective areas based on light data, optimizing power usage by only processing data from effective areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If power is continuously supplied to all pixels in the pixel array, then complete light data collection is maintained, but power consumption increases

Engineering Contradiction:

Improvepower consumptionVSAvoidlight data collection completeness

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The pixel array is divided into effective area pixels and non-effective area pixels based on light collection capability. The controller selectively activates only the effective area pixels for PPG signal acquisition, while keeping non-effective area pixels inactive. This segmentation resolves the contradiction by maintaining data collection reliability in the effective area while eliminating unnecessary power consumption in non-effective areas.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the pixel array are assigned different functional qualities: effective area pixels are configured for active light collection and PPG signal generation, while non-effective area pixels are either disabled or configured for alternative purposes. This local differentiation allows the system to maintain measurement reliability where needed while reducing overall power consumption.

Inventive Principle:

Principle #3Local quality

2Area of stationary object

If all pixels in the pixel array are activated for light collection, then measurement coverage is maximized, but power consumption increases

Engineering Contradiction:

Improvemeasurement coverage areaVSAvoidpower consumption

Core Design Contradiction:

Area of stationary objectVSUse of energy by moving object

Solution Approach 1:

The pixel array is segmented into effective and non-effective areas based on optical performance characteristics. Only the effective area pixels are activated for measurement, providing sufficient coverage for accurate PPG signal acquisition without the penalty of powering the entire array. This resolves the contradiction between coverage area and power consumption.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of activating the entire pixel array (excessive action), the system activates only the necessary effective area pixels (partial action) required for reliable PPG measurement. This partial activation achieves the minimum necessary measurement coverage while significantly reducing power consumption compared to full-array activation.

Inventive Principle:

Principle #16Partial or excessive action

3Loss of information

If the entire pixel array is processed for PPG data generation, then data completeness is maintained, but processing overhead and power consumption increase

Engineering Contradiction:

ImprovePPG data completenessVSAvoidprocessing power

Core Design Contradiction:

Loss of informationVSUse of energy by stationary object

Solution Approach 1:

The controller extracts and processes only the pixel data from the effective area pixels, excluding data from non-effective area pixels. This extraction approach ensures that complete and reliable PPG data is generated from the functional pixels while avoiding the processing overhead and power consumption associated with handling data from non-functional pixels.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs preliminary identification of effective versus non-effective area pixels before PPG data generation. By pre-segmenting the pixel array and identifying which pixels will contribute useful data, the system avoids unnecessary processing of ineffective pixel data, thereby reducing processing power consumption while maintaining data completeness from functional pixels.

Inventive Principle:

Principle #10Preliminary action

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 solution enhances power efficiency by reducing power consumption in PPG sensors, allowing them to operate longer on limited power sources and improve battery life in wearable devices.

Implementation Method 1

a pixel array that collects light

Methodology Applied

Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentUS11540738B2PPG sensor and method of operating the same

Publication Date: 2023.01.03 SAMSUNG ELECTRONICS CO LTD

AI summary

A photoplethysmogram (PPG) sensor includes a pixel array that collects light, a pixel sampler that converts the light collected through the pixel array into a plurality of pixel data, an effective area determiner that determines an effective area and a non-effective area of the pixel array based on the pixel data, a power controller that is operable to cut off power to the non-effective area of the pixel array, and a PPG data generator that generates PPG data from pixel data corresponding to the effective area among the pixel data.