Arterial Pressure Estimation via Respiratory Cycle Correction

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Solution Overview

Problem

Current techniques for estimating left intracardiac pressure are invasive and suffer from inaccuracies due to respiratory variations, making it difficult to obtain a precise arterial pressure waveform.

Innovation Solution

An arterial-pressure estimation apparatus that acquires and corrects sensor data to account for respiratory cycles, using weighting coefficients based on invasive examination waveforms to estimate changes in arterial pressure over time, allowing for noninvasive and accurate estimation of left ventricular end-diastolic pressure (LVEDP).

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If direct measurement of left intracardiac pressure is performed by inserting a sensor into the heart, then measurement precision is improved, but device complexity and invasiveness increase

Engineering Contradiction:
Improvemeasurement precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses an intermediary approach by measuring arterial pressure waveform and respiratory variation noninvasively, then using these as intermediate parameters to estimate left intracardiac pressure through calculation, avoiding direct sensor insertion into the heart while achieving the measurement goal

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical invasive sensor insertion system with a noninvasive measurement system that uses acoustic sensors and pressure sensors to detect blood flow timing and arterial pressure, substituting direct mechanical measurement with indirect detection methods

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If data is collected over multiple beats to improve measurement reliability, then reliability is improved, but measurement precision deteriorates due to respiratory variation

Engineering Contradiction:
ImprovereliabilityVSAvoidmeasurement precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent extracts and separates the respiratory variation component from the arterial pressure waveform by detecting the respiration cycle and identifying inspiration periods, then removes the influence of these variations through correction calculations to isolate the true arterial pressure signal

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent implements feedback by using the detected respiration cycle information to dynamically correct the arterial pressure waveform data, where the respiratory variation detection provides feedback that is used to adjust and improve the accuracy of the final pressure estimation

Inventive Principle:
Principle #23Feedback

3Ease of operation

If arterial pressure waveform is estimated using conventional techniques, then ease of operation is maintained, but measurement precision deteriorates due to inability to correct respiratory variation

Engineering Contradiction:
Improveease of operationVSAvoidmeasurement precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent achieves multi-functionality by using a single noninvasive measurement system to simultaneously detect arterial pressure waveform, determine respiration cycle, identify inspiration periods, and estimate left intracardiac pressure, consolidating multiple functions into one integrated device that maintains ease of operation

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4285815A1Arterial pressure estimation device, arterial pressure estimation system, and arterial pressure estimation method
Publication Date: 2023.12.06 TERUMO KK
  • EP4285815A1 patent drawingFigure 1
  • EP4285815A1 patent drawingFigure 2
  • EP4285815A1 patent drawingFigure 3

AI summary

An arterial-pressure estimation apparatus includes a control unit configured to acquire sensor data indicating, as a blood flow timing, a timing at which a blood flow generated at one or more locations of a blood vessel downstream of an aorta is detected for each heartbeat when the one or more locations is compressed while a pressure is gradually reduced, record a value of the pressure corresponding to each blood flow timing, correct the value of the pressure corresponding to the blood flow timing included in an inspiration period of a respiration cycle, and estimate a change in an arterial pressure over time by referring to the acquired sensor data and the recorded and corrected value of the pressure.