Blood Pressure Measurement Using Wavelet Transform
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing blood pressure monitoring techniques, particularly oscillometric methods, face limitations such as requiring multiple oscillations and a long monitoring period for accurate measurements, causing patient discomfort, and being prone to errors due to external noise and artifacts, which traditional filtering techniques often fail to address without distorting the signal.
Innovation Solution
The use of a continuous wavelet transform to represent the pressure signal in a suitable domain, allowing for the identification of ridges in the transformed signal, which correspond to the oscillation envelope, enabling more accurate and efficient determination of blood pressure measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional filtering techniques are used to remove noise and artifacts from the oscillation signal, then noise removal is achieved, but the oscillation signal is distorted
Solution Approach 1:
The patent introduces wavelet transform as an intermediary tool that operates in the time-frequency domain to separate noise from the oscillation signal without directly filtering the signal itself. This mediator approach allows noise removal while preserving the integrity of the oscillation signal characteristics
Solution Approach 2:
The patent transforms the problem from the time domain to the time-frequency domain using wavelet transform. By changing the dimension of analysis, the system can identify and remove noise components that are not present in the oscillation signal's frequency spectrum, thereby avoiding signal distortion
2Measurement precision
If many oscillations are monitored to obtain accurate blood pressure measurements, then measurement accuracy is improved, but the monitoring period is extended causing patient discomfort
Solution Approach 1:
The patent changes the parameter of analysis from simple peak detection to wavelet transform coefficients analysis. This parameter change enables the system to extract blood pressure information from fewer oscillations by utilizing the time-frequency characteristics embedded in the wavelet coefficients, thereby reducing the required monitoring period
Solution Approach 2:
The patent replaces the traditional mechanical approach of counting multiple oscillations with a signal processing approach using wavelet transform. This substitution allows the system to obtain accurate measurements from fewer oscillations by extracting features in the time-frequency domain rather than relying on temporal accumulation of oscillations
Data Source
Figure 1
Figure 2(a)
Figure 2(b)
AI summary
Methods and systems for determining blood pressure from a pressure signal are disclosed. A patient's blood pressure may be determined by analyzing features of a wavelet transformation of a pressure signal obtained during an occlusion procedure. Ridges in a scalogram of the transformed signal may be identified and used to determine an envelope of a pressure oscillation signal, to which oscillometric blood pressure determination techniques may be applied.