METHOD AND SYSTEM FOR ANALYZING A PATIENT'S RESPIRATORY ACTIVITY AND CORRESPONDING USES

• US 20130096452A1
• Filed: 04/28/2011
• Published: 04/18/2013
• Est. Priority Date: 04/30/2010
• Status: Active Grant

• Current Assignee: Centre National De La Recherche Scientifique
• Original Assignee: Centre National De La Recherche Scientifique
• Inventors: Hanusse, Patrick
• Granted Patent: US 9,649,051 B2
• Time in Patent Office: Days
• US Class Current: 600/538
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/72 Signal processing specially adapted for physiological signals or for diagnostic purposes character recognition, recognising digital ink, document-oriented image-based pattern recognition G06V30/00; recognition or understanding of postal images G06V30/424
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/7271 Specific aspects of physiological measurement analysis A61B5/316, A61B5/349 and A61B5/374 take precedence
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: G06F 17/141 Discrete Fourier transforms

Abstract

This method for analyzing the respiratory activity of a patient comprises the steps (20) for acquiring at least one respiratory activity signal comprising at least one elementary signal corresponding to a respiratory cycle, the general form of which may be expressed by x(t)=x₀+x₁ cos (Φ(t)), wherein Φ(t) is the phase of said elementary signal, and for analyzing (24, 26, 28) said respiratory activity signal. This analysis (24, 26, 28) comprising steps (24) for extracting, from said respiratory activity signal, said elementary signal, for determining (26) an expression of a phase equation

$F\left(\Phi \right)=\frac{\Phi }{t}$

of said elementary signal and for determining (26) an expression of the phase Φ(t) of said elementary signal as a function of parameters measuring the anharmonicity of said elementary signal and its morphology, from pcos_n and psin_n functions defined by:

$p{\cos }_n\left(t,r\right)=\sum _{k=1}^{\infty }\cos \left(\mathrm{kt}\right)\frac{r^k}{k^n}\mathrm{and}p{\sin }_n\left(t,r\right)=\sum _{k=1}^{\infty }\sin \left(\mathrm{kt}\right)r\frac{r^k}{k^n}.$

Claims

1. A method for analyzing the respiratory activity of a patient, comprising steps for acquiring at least one respiratory activity signal comprising at least one elementary signal corresponding to a respiratory cycle, the general form of which may be expressed by x(t)=x₀+x₁ cos (Φ

(t)) wherein Φ

(t) is the phase of said elementary signal and for analyzing said respiratory activity signal, wherein the analysis of said respiratory activity signal comprises the following steps;

extracting, from said respiratory activity signal, said elementary signal;

determining an expression of a phase equation

2. The method for analyzing respiratory activity according to claim 1, wherein the phase equation is expressed as:

3. The method for analyzing respiratory activity according to claim 2, wherein the elementary signal is expressed by two parameters r and Φ

₀, as;

x(t)=x₀+a₁h sin (t, r)+b₁h cos (t, r)

wherein a₁=x₁ cos (Φ

₀) and b₁=−

x₁ sin (Φ

₀), the hsin and hcos functions being defined by;

4. The method for analyzing respiratory activity according to claim 1, wherein the phase equation is expressed as:

5. The method for analyzing respiratory activity according to claim 4, wherein the expression of the phase Φ

(t) is determined as;

6. A system for analyzing the respiratory activity of a patient comprising a component configured to acquire a respiratory activity signal comprising at least one elementary signal corresponding to a respiratory cycle, the general form of which may be expressed by x(t)=x₀+x₁ cos (Φ

(t)), wherein Φ

(t) is the phase of said elementary signal and a processor configured to analyze said respiratory activity signal, wherein the processor comprises;

a component configured to extract from respiratory activity signal, said elementary signal;

a component configured to determine an expression of a phase equation

7. The system for analyzing respiratory activity according to claim 6, comprising a processor configured to express the phase equation as:

8. The system for analyzing respiratory activity according to claim 7, comprising a component configured to express said elementary signal by two parameters r and Φ

₀, as;

x(t)=x₀+a₁h sin (t,r)+b₁h cos (t,r)

wherein a₁=x₁ cos (Φ

₀) and b₁=−

x₁ sin (Φ

₀), the hsin and hcos functions being defined by;

9. The system for analyzing respiratory activity according to claim 8, comprising a component configured to express the phase equation as:

10. The system for analyzing respiratory activity according to claim 9, comprising a component configured to express the phase Φ

(t) as;

11. A respiratory assistance device comprising a system for analyzing respiratory activity according to claim 6.

12. A respiratory monitoring device comprising a system for analyzing respiratory activity according to claim 6.