Spirometer Flow-Volume Angle for Emphysema Diagnosis
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Solution Overview
Problem
Current methods for diagnosing chronic obstructive pulmonary disease (COPD) and estimating the severity of emphysema are inaccurate in distinguishing airway obstruction from emphysema and do not effectively quantify airway collapse during forced expiration.
Innovation Solution
A computerized system and apparatus that uses a spirometer to measure and calculate the flow-volume curve and angle between best fitting linear regression curves during forced expiration, correlating airway collapse with the presence and severity of emphysema through a mathematical model comparing patient data with reference profiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current lung function tests such as respirometry are used to diagnose COPD, then the diagnosis can be obtained, but the accuracy in distinguishing airway obstruction from emphysema is insufficient
Solution Approach 1:
The patent segments the diagnosis process into distinct components: calculating the flow-volume curve from spirometry data, fitting linear regression curves to specific portions of the flow-volume loop, and determining the beta angle as a separate diagnostic parameter. This segmentation allows for more precise differentiation between airway obstruction and emphysema by analyzing specific geometric characteristics of the flow-volume loop rather than relying on traditional respiratory function parameters alone.
2Measurement precision
If traditional flow-volume curve analysis is used, then airway obstruction can be detected, but emphysema severity cannot be accurately quantified
Solution Approach 1:
The patent transforms the flow-volume curve analysis by introducing a new parameter - the beta angle - which is derived from the geometric configuration of the flow-volume loop. By fitting linear regression curves to the expiratory portion of the loop and calculating the angle between them, the method converts complex airway collapse dynamics into a single, quantifiable parameter that directly correlates with emphysema severity, making the measurement both accurate and clinically practical.
3Measurement precision
If radiological imaging is used for emphysema diagnosis, then accurate detection can be achieved, but the complexity and cost of the diagnostic process increases
Solution Approach 1:
The patent replaces the need for complex radiological imaging systems with a simplified mechanical/spirometric approach. By using standard spirometry equipment to capture flow-volume data and then applying mathematical analysis (linear regression and angle calculation), the method achieves emphysema detection accuracy comparable to radiological methods but without requiring CT scanners or other advanced imaging equipment, thereby reducing device complexity and diagnostic cost.
Data Source
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AI summary
The present invention relates generally to diagnosing chronic obstructive pulmonary disease (COPD) and estimating of the severity thereof, in particularly the occurrence of emphysema. More particularly the present invention relates to a system and method for computerized quantification of airway collapse during forced expiration or total exhalation. Such airway collapse is correlated with the presence of emphysema that has been verified on computer tomography (CT) scan and that is due to the loss of alveolar attachments in emphysema. Moreover the present invention provides a computerized apparatus for detection of emphysema, a computerized system for detection of emphysema or a method of computer-aided detection of emphysema. This can also be used for quantifying the severity of emphysema in patients with COPD by an automated analysis of measurement of the amount (volume) and/or speed (flow) of a total or forced exhalation or the processing of the graphics of a pneumotachograph of a total or forced exhalation. Such measurements are obtainable by a spirometer. The apparatus, system or method of present invention correlates airway collapse during forced expiration in COPD with presence and severity of emphysema It was demonstrated that airway collapse during forced expiration could be quantified by measuring the angle between the two best fitting regression lines describing the cloud of point measurements obtained from peakflow to the end of forced expiration. Such angle in COPD correlates with presence and severity of emphysema, as assessed by computer tomography scan.