Optical Blood Pressure Sensing with Force-Based Pulse Analysis

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Solution Overview

Problem

Existing non-invasive blood pressure measurement techniques lack accuracy and reliability for continuous monitoring, and there is no device with proven effectiveness for continuous and non-invasive blood pressure measurement.

Innovation Solution

An apparatus and method using a light sensor to measure light intensity of specific wavelength ranges reflected from the skin, analyzing pulse amplitudes to determine systolic and diastolic blood pressure based on applied force thresholds and integrals, incorporating a processor to analyze these measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If non-invasive blood pressure measurement techniques are used, then subject comfort is improved and hospitalization requirements are reduced, but measurement accuracy and reliability deteriorate

Engineering Contradiction:

Improvesubject comfortVSAvoidblood pressure measurement accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The measurement process is segmented into multiple discrete force levels applied to the sensor, with pulse amplitude measured at each level. This segmentation allows systematic analysis of the relationship between applied force and pulse amplitude, enabling accurate blood pressure determination through threshold identification without requiring complex cuff inflation mechanisms.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent replaces the traditional mechanical cuff inflation system with a direct contact light sensor that applies controlled force directly to the skin. This substitution eliminates the need for bulky cuffs and inflation mechanisms, improving comfort while enabling continuous measurement through direct optical-mechanical interaction at the skin surface.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If continuous blood pressure monitoring is implemented, then real-time physiological data is obtained, but measurement reliability and accuracy deteriorate due to lack of proven effectiveness

Engineering Contradiction:

Improvecontinuous monitoring capabilityVSAvoidmeasurement reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system enables continuous blood pressure monitoring by maintaining constant contact between the light sensor and skin, continuously measuring pulse amplitude at multiple force levels, and continuously determining blood pressure values without interruption. This continuous measurement process provides real-time physiological data while maintaining reliability through consistent application of the multi-force-level analysis method.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The system incorporates feedback by continuously analyzing the relationship between applied force and measured pulse amplitude, using the identified thresholds to determine blood pressure values. This feedback mechanism ensures that continuous measurements remain accurate and reliable by constantly referencing the established force-amplitude relationship.

Inventive Principle:

Principle #23Feedback

3Measurement precision

If multiple measurement parameters are analyzed, then blood pressure determination accuracy is improved, but device complexity increases

Engineering Contradiction:

Improveblood pressure determination accuracyVSAvoiddevice complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The light sensor serves multiple functions: it measures light intensity for pulse amplitude determination, applies controlled force to the skin, and enables continuous monitoring. This multi-functionality allows the device to achieve accurate blood pressure determination through multiple measurement parameters while minimizing device complexity by using a single integrated sensor platform.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Enables accurate and reliable continuous non-invasive blood pressure measurement by considering both optical and mechanical properties of blood, providing comfort without the need for a wearable cuff.

Implementation Method 1

acquire, from a light sensor, measurements of an intensity of light of a first wavelength range reflected from the skin of the subject

Methodology Applied

Scientific EffectLight reflection: Reflection

Data Source

PatentUS12533035B2Apparatus and method and computer program product for determining a blood pressure measurement

Publication Date: 2026.01.27 KONINKLIJKE PHILIPS NV

AI summary

There is provided an apparatus (100) for determining a blood pressure measurement for a subject (102). The apparatus (100) comprises a processor (104) configured to acquire, from a light sensor (106), measurements of an intensity of light (108) of a first wavelength range reflected from the skin (110) of the subject (102) for a range of forces at which the light sensor (106) is applied to the skin. The processor (104) is further configured to determine a pulse amplitude from the measurements of light intensity at the range of applied forces and analyze the determined pulse amplitudes to determine a systolic blood pressure measurement based on the applied force at which the pulse amplitude drops below a predefined threshold and/or an integral of the pulse amplitudes and/or a diastolic blood pressure measurement based on the applied force at which an initial rise in the pulse amplitude is identified.