Pulse Wave Measurement Using Differential Amplification and Integration

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Solution Overview

Problem

Existing pulse wave measuring methods require high sampling frequencies when measuring pulse transit time between two close points, which can be impractical and inaccurate, especially when signal magnitudes are small.

Innovation Solution

A pulse wave measuring apparatus and method that differentially amplifies and integrates pulse wave signals from two points, followed by analog-to-digital conversion, to obtain pulse transit time without being affected by sampling frequency, using components like differential amplifiers, integrators, and digital signal processors to enhance accuracy and reduce computational requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If pulse wave signals are measured at two close points to obtain pulse transit time, then measurement precision is improved, but sampling frequency requirements increase significantly

Engineering Contradiction:

Improvepulse transit time measurement accuracyVSAvoidsampling frequency requirement

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent applies preliminary action by performing analog signal processing (differential amplification and integration) on the pulse wave signals before digital acquisition. The integrator accumulates the signal voltage over time, creating a smoothed signal that reduces the impact of high-frequency noise and allows for lower sampling frequencies while maintaining measurement precision.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an integrator as an intermediary component between the signal source and the digital processor. This integrator acts as a mediator that transforms the raw pulse wave signals into integrated voltage values, which can then be processed at lower sampling rates while preserving the essential timing information needed for accurate pulse transit time measurement.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If electrocardiogram signal measurement is used to obtain pulse transit time, then measurement precision is improved, but device complexity increases due to required contact with hands or chest patch

Engineering Contradiction:

Improvepulse transit time measurement accuracyVSAvoidcontact requirement with body

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the essential measurement function from the complex electrocardiogram-based system. Instead of requiring chest patches or hand contacts to measure electrical cardiac signals, the invention extracts only the pulse wave measurement capability from the extremity, eliminating the need for complex electrical contact while maintaining pulse transit time measurement accuracy through optical or other non-contact sensing methods.

Inventive Principle:

Principle #2Taking out (Extraction)

3Measurement precision

If smaller distance between two measurement points is used, then pulse transit time measurement accuracy is improved, but required sampling frequency increases

Engineering Contradiction:

Improvepulse transit time measurement accuracyVSAvoidsampling frequency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

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

Enables accurate measurement of pulse transit time with reduced computational power and sampling frequency requirements, suitable for mobile health management systems and wearable devices, while improving signal processing accuracy.

Implementation Method 1

an analog signal processor configured to amplify a voltage difference between two pulse wave signals from among the received pulse wave signals

Methodology Applied

Scientific EffectDifferential amplification:

Implementation Method 2

integrate the amplified voltage difference

Methodology Applied

Scientific EffectIntegration:

Implementation Method 3

a digital signal processor configured to analog to digital (AD) convert a value of the integrated amplified voltage difference

Methodology Applied

Scientific EffectAnalog-to-digital conversion:

Implementation Method 4

a light emitter configured to emit light to the object, wherein the receiver may be further configured to receive at least one of light that is emitted from the light emitter and pass through the object and light that is emitted from the light emitter and reflected from the object, photoelectrically convert the received light, and generate the pulse wave signals

Methodology Applied

Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentUS10159417B2Apparatus and method for measuring pulse wave

Publication Date: 2018.12.25 SAMSUNG ELECTRONICS CO LTD

AI summary

There are provided an apparatus and a method for measuring pulse waves. The pulse wave measuring apparatus includes a receiver configured to receive pulse wave signals sensed at at least two points of an object; an analog signal processor configured to amplify a voltage difference between two pulse wave signals from among the received pulse wave signals and integrate the amplified voltage difference; and a digital signal processor configured to analog to digital convert a value of the integrated amplified voltage difference and obtain, from the converted value, a pulse transit time between the two points corresponding to the two pulse wave signals.