Pulse Wave Velocity Estimation Using ECG and PPG Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for measuring pulse wave velocity (PWV) are complex, require specialized equipment, and are not suitable for widespread clinical use due to difficulties in interpretation and the need for multiple measurements across varying blood pressure levels.
Innovation Solution
A method that estimates PWV using electrocardiogram (ECG) and photo-plethysmograph (PPG) signals, combined in a formula that takes into account the patient's age, carotid-femoral distance, and pulse arrival time (PAT), allowing for continuous monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If MRI or ultrasound/tonometry techniques are used to measure PWVcf, then measurement precision is improved, but device complexity and ease of operation deteriorate
Solution Approach 1:
The patent replaces complex mechanical imaging systems (MRI) and specialized ultrasound/tonometry equipment with simple optical sensors (photodetectors) that capture light absorption changes in the finger. This substitution dramatically simplifies the device while maintaining measurement capability through photoplethysmography signals.
Solution Approach 2:
The patent uses a simplified optical copy approach by measuring pulse wave characteristics at an accessible peripheral site (finger) rather than directly at the carotid-femoral path. The finger PPG signal serves as a proxy that can be processed to estimate central PWVcf, avoiding the need for complex direct measurement equipment.
2Measurement precision
If MRI or ultrasound/tonometry techniques are used to measure PWVcf, then measurement precision is improved, but ease of operation deteriorates
Solution Approach 1:
The patent replaces techniques requiring trained operators (ultrasound Doppler, tonometry) with automatic optical detection using standard photodetectors. The system automatically processes the PPG signal to extract pulse arrival time, eliminating the need for specialized training in signal acquisition and interpretation.
Solution Approach 2:
The patent implements automatic signal processing where the system itself performs the measurement and calculation without requiring operator intervention for timing measurements or data analysis. The microprocessor automatically detects pulse arrival times and calculates PWVcf from the PPG waveform, making the system self-sufficient and easy to operate.
3Measurement precision
If multiple PWVcf measurements are taken at varying blood pressure levels, then measurement precision is improved, but loss of time increases
Solution Approach 1:
The patent enables continuous monitoring of PWVcf by continuously capturing PPG signals and automatically processing them in real-time. This allows multiple measurements to be taken over time without interrupting the monitoring process, capturing blood pressure variations naturally occurring during anesthesia rather than requiring scheduled measurement intervals.
Solution Approach 2:
The patent performs preliminary processing of the PPG signal to extract pulse arrival time information continuously as the signal is acquired. By preparing and analyzing the signal in real-time rather than requiring post-processing of discrete measurements, the system eliminates delays between measurements and enables immediate calculation of PWVcf at each time point.
4Measurement precision
If specialized equipment and training are required for PWVcf measurement, then measurement precision is improved, but productivity decreases
Solution Approach 1:
The patent replaces specialized medical equipment requiring expert operation with standard photodetector technology and automatic processing. This substitution enables any trained technician to perform measurements without requiring expertise in ultrasound or tonometry, dramatically increasing the number of patients that can be screened.
Solution Approach 2:
The patent uses a universal photodetector-based platform that can be integrated into existing anesthesia monitoring equipment. This multi-functional approach allows the same device to perform both standard anesthesia monitoring and PWVcf measurement simultaneously, eliminating the need for separate specialized equipment and increasing operational efficiency.
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 method provides a simple, cost-effective, and continuous estimation of PWV, enabling dynamic and personalized analysis of arterial stiffness, which can improve cardiovascular risk stratification.
Implementation Method 1
a value corresponding to the pulse arrival time (PAT) determined from an electrocardiogram (ECG) signal and a value corresponding to a photoplethysmography (PPG) signal
Implementation Method 2
a value corresponding to the pulse arrival time (PAT) determined from an electrocardiogram (ECG) signal and a value corresponding to a photoplethysmography (PPG) signal
Implementation Method 3
combining the age of the patient, the carotid-femoral distance of the patient and the pulse arrival time (PAT) in a function to obtain a value corresponding to an estimated pulse wave velocity (PWV)
Data Source
AI summary
The invention pertains to a method and system for measuring pulse wave velocity (PWV), using the pulse arrival time (PAT) and the carotid-femoral distance, as well as the age of the patient.