Cuffless Doppler PAD Detection via C-Notch Waveform Analysis
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Solution Overview
Problem
Current methods for diagnosing peripheral arterial disease (PAD) are inaccurate for calcified lesions, require skilled personnel, and are painful or impractical for certain patient groups, leading to underdiagnosis and suboptimal treatment.
Innovation Solution
A system using a wireless continuous wave Doppler transceiver, waveform converter, and processor that analyzes Doppler waveforms to detect the presence or absence of PAD by identifying the 'C-notch' in blood flow, reducing the need for skilled personnel and enabling testing in various patient positions, including those with wounds or calcification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional pressure cuff methods are used to diagnose PAD, then measurement can be obtained, but the method is painful and impractical for certain patient groups (diabetics, amputees, patients with wounds)
Solution Approach 1:
The patent extracts the Doppler audio signal detection from the traditional pressure cuff measurement system. By using a cuffless Doppler transceiver that directly captures blood flow audio signals without requiring pressure cuff inflation, the harmful mechanical compression is eliminated while preserving the diagnostic capability through alternative signal acquisition
2Measurement precision
If ABI measurement methods are used to diagnose PAD, then diagnosis can be performed, but the methods require skilled personnel and are inaccurate for calcified lesions
Solution Approach 1:
The patent replaces the mechanical pressure cuff system with an acoustic Doppler detection system. The continuous wave Doppler transceiver captures blood flow audio signals and uses waveform analysis (specifically C-notch detection) to diagnose PAD, eliminating the need for manual pressure measurement and interpretation while providing consistent diagnostic accuracy regardless of calcification
Solution Approach 2:
The system incorporates automated waveform analysis that automatically detects C-notches and determines PAD presence without requiring skilled personnel interpretation. The processor autonomously analyzes the Doppler audio signals and provides diagnostic results, making the system self-sufficient and eliminating the dependency on operator expertise
3Extent of automation
If automated waveform analysis is implemented, then skilled personnel are not needed, but system complexity increases
Solution Approach 1:
The waveform converter and processor are designed to perform multiple functions: converting Doppler audio signals, detecting C-notches, analyzing waveforms, and providing diagnostic results. By consolidating these functions into a single multi-functional device, the automation level increases while the overall system complexity remains manageable through functional integration
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 system provides accurate and reliable PAD diagnosis with a sensitivity of 95.1%, specificity of 98.2%, and accuracy of 96.8%, effectively identifying significant disease without the need for invasive pressure cuffs or highly trained personnel.
Implementation Method 1
a Doppler transceiver, a waveform converter and processor
Data Source
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AI summary
A system for determining peripheral artery disease and method of use for determining the presence or absence of peripheral vascular disease and the severity of the disease in particular vascular segments. The System for determining peripheral artery disease and method of use includes a continuous wave Doppler transceiver which generates a digitized version of quadrature detected stereo audio and is coupleable to a waveform converter and processor. The waveform converter and processor provides filtering, time domain to frequency domain conversion, gain control, and statistical processing of the converted Doppler Stereo audio and is operationally coupled to a display for presenting results to a technician.