Finger Blood Pressure Bladder Layout for Accurate Oscillometric Sensing

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Solution Overview

Problem

Existing blood pressure measurement systems using inflatable bladders that fully surround and compress the finger are inaccurate and require additional electromagnetic radiation for precise readings.

Innovation Solution

A vital sign measuring device (VSMD) with an arcuate inflatable bladder that contacts only a portion of the finger, particularly the underside, and uses a separate structure to apply pressure from the top, enhancing contact with digital arteries and reducing finger movement, thereby improving signal quality and accuracy without electromagnetic radiation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If an inflatable bladder fully surrounds and compresses the finger, then the finger is stabilized during measurement, but measurement precision deteriorates due to inaccurate blood pressure readings

Engineering Contradiction:

Improvefinger stabilityVSAvoidblood pressure measurement accuracy

Core Design Contradiction:

Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The measurement system is divided into two separate components: an inflatable bladder that contacts only the bottom portion of the finger for stabilization, and a separate force application mechanism that applies pressure to the top of the finger. This segmentation allows each component to perform its specific function optimally without interfering with measurement accuracy.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The inflatable bladder is designed to contact only specific localized areas of the finger (the bottom portion) rather than fully surrounding it. This localized contact provides sufficient stabilization while leaving the digital arteries accessible for accurate pressure measurement, demonstrating that full circumferential contact is not necessary for stability.

Inventive Principle:

Principle #3Local quality

2Ease of operation

If an inflatable bladder fully contacts the finger periphery, then the finger is secured during measurement, but measurement precision deteriorates due to compression artifacts

Engineering Contradiction:

Improvefinger securingVSAvoidblood pressure measurement accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The system separates the finger-securing function (performed by the inflatable bladder contacting only the bottom portion) from the pressure measurement function (performed by the separate force application mechanism). This allows the finger to be securely held without the measurement being corrupted by full periphery compression.

Inventive Principle:

Principle #1Segmentation

3Measurement precision

If electromagnetic radiation is used for measurement, then measurement precision can be improved, but device complexity increases due to additional sensors and processing requirements

Engineering Contradiction:

Improveblood pressure measurement accuracyVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex optical/electromagnetic measurement systems with a simplified mechanical oscillometric measurement system. By using a pressure sensor to detect mechanical oscillations in the inflatable bladder during the oscillometric deflation phase, the system achieves accurate blood pressure measurement without requiring light sensors, LEDs, or complex signal processing algorithms associated with optical methods.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 VSMD significantly increases the amplitude of the oscillometric signal, reduces noise, and provides more accurate and repeatable systolic and diastolic blood pressure measurements, while also measuring other vital signs like pulse rate, glucose levels, and temperature without the need for electromagnetic radiation.

Implementation Method 1

the microprocessor analyzes an oscillometric signal provided by the pressure sensor to provide an indication of blood pressure

Methodology Applied

Scientific EffectOscillometric method:

Implementation Method 2

a pressure sensor adapted to provide an oscillometric signal in response to pressure applied by the inflatable bladder

Methodology Applied

Scientific EffectPressure sensing: Piezoresistive Effect

Data Source

PatentUS20260060559A1Apparatus and method for measuring blood pressure via a finger

Publication Date: 2026.03.05 ARC DEVICES LTD

AI summary

There is disclosed an apparatus for facilitating measurement a person's blood pressure via the person's finger by means of an inflatable measurement bladder adapted to contact an underside of a finger defining a finger pad. A structure or other implement applies a downward force on a top portion of the finger opposite the finger pad. Blood pressure may be determined without the use of any electromagnetic radiation, such as miniature dynamic light sensing (mDLS).