Method and system for analyzing respiratory tract sounds

• US 20030139679A1
• Filed: 01/09/2003
• Published: 07/24/2003
• Est. Priority Date: 01/10/2002
• Status: Active Grant

• Current Assignee: Deep Breeze, Ltd.
• Original Assignee: Deep Breeze, Ltd.
• Inventors: Kushnir, Igal, Botbol, Meir
• Granted Patent: US 6,887,208 B2
• Time in Patent Office: Days
• US Class Current: 600/529
• CPC Class Codes: A61B 5/08 Detecting, measuring or recording devices for evaluating the respiratory organs A61B5/0205 takes precedence
• CPC Class Codes: A61B 7/003 Detecting lung or respiration noise
• CPC Class Codes: A61B 7/026 comprising more than one sound collector

Abstract

A method and system for analyzing respiratory tract sounds in an individual. A plurality of N transducers are fixed over the thorax. The ith transducer is fixed at a location x_i, and generates a signal P(x_i,t) indicative of pressure waves at the location x_i, for i=1 to N. A processor receives the signals P(x_i,t) and determines an average acoustic energy {tilde over (P)}(x,t₁,t₂) at at least one position x over a time interval where {tilde over (P)}_is determined in an algorithm involving at least one of the signals P(x_i,t).

Claims

1. A system for analyzing sounds in at least a portion of an individual'"'"'s respiratory tract comprising:

(a) a plurality of N transducers, each transducer configured to be fixed on a surface of the individual over the thorax, the ith transducer being fixed at a location x_i and generating a signal P(x_i, t) indicative of pressure waves at the location x_i;

for i=1 to N; and

(One) a processor configured to receive the signals P(x_i,t) and determine an average acoustic energy {tilde over (P)}(x, t₁, t₂) at at least one position x over a time interval from a first time t₁ to a second time t₂, {tilde over (P)} being determined in an algorithm involving at least one of the signals P(x_i, t).

2. The system according to claim 1 further comprising a two-dimensional display device.

3. The system according to claim 2 wherein the processor is further configured to display a representation of the function P on the display device.

4. The system according to claim 1 wherein the processor is further configured to compare the average acoustic energy {tilde over (P)} to one or more predetermined functions {tilde over (F)} and determine a function {tilde over (F)}₀ from among the functions {tilde over (F)} most similar to {tilde over (P)}.

5. The system according to claim 4 wherein the processor is further configured to make a diagnosis based upon the determined function.

6. The system according to claim 1 wherein the average acoustic energy {tilde over (P)} over a time interval from t₁ to t₂ is determined at a location x_i of a transducer using the algebraic expression:

7. The system according to claim 1 wherein the function {tilde over (P)} is determined at one or more locations x in an algorithm comprising:

(One) determining an average acoustic energy {tilde over (P)}(x,t₁,t₂) over a time interval from t₁ to t₂ at a plurality of locations x_i of transducers; and

(Two) determining an average acoustic energy {tilde over (P)}(x,t₁,t₂) at at least one location x by interpolation of the determined {tilde over (P)}(x,t₁,t₂).

8. The system according to claim 7 wherein an average acoustic energy {tilde over (P)}(x_i,t₁, t₂) is determined over a time interval from t₁ to t₂ at a plurality of locations x_i of transducers using the algebraic expression:

9. The system according to claim 7 wherein an average acoustic energy is determined at at least one location x by interpolation of the determined {tilde over (P)}(x_i,t₁,t₂) using the algebraic expression:

10. The system according to claim 9 wherein g(x,v_iσ

)is the kernel g(x,x_i,σ

)=

11. The system according to claim 1 wherein the processor is configured to determine an average acoustic energy over a plurality of successive time intervals, each average acoustic energy being determined using an algorithm involving at least one of the signals P(x_i,t).

12. The system according to claim 11 wherein the processor is configured to sequentially display on a display device a representation of each determined average acoustic energy.

13. The system according to claim 1 wherein the processor is configured to:

(One) for each of one or more frequency bands,

(Twenty-seven) subject the signals (P,x_i,t) to band pass filtering in the frequency band; and

(ab) determine an average acoustic energy function for the frequency band based upon at least one of the filtered signals.

14. The system according to claim 13 wherein the processor is configured to display one or more of the average acoustic energy functions determined for a frequency band on a display device.

29. The use according to claim 1 wherein the disorder is selected from the group comprising at least pleural effusion and pneumonia.

15. A method for analyzing sounds in at least a portion of an individual'"'"'s thorax, comprising:

(One) obtaining N signals P(x_i,t) for i=1 to N, the signal P(x_i,t) being indicative of pressure waves at the location x_i;

on a surface of the body over the thorax;

(Two) determining an average acoustic energy {tilde over (P)}(x,t₁,t₂)at at least one position x over a time interval from a first time t₁ to a second time t₂, {tilde over (P)} determined in an algorithm involving at least one of the signals.

16. The method according to claim 15 further comprising displaying a representation of {tilde over (P)} on a two-dimensional surface.

17. The method according to claim 15 further comprising comparing the average acoustic energy {tilde over (P)} to one or more predetermined functions {tilde over (F)} and determining a function {tilde over (F)}₀ from among the functions {tilde over (F)} most similar to {tilde over (P)}.

18. The method according to claim 15 wherein further comprising making a diagnosis based upon the determined function.

19. The method according to claim 15 wherein the average acoustic energy over a time interval from t₁ to t₂ is determined at a location x_i of a transducer using the algebraic expression:

20. The method according to claim 15 wherein the function {tilde over (P)} is determined at one or more locations x in an algorithm comprising:

(One) determining an average acoustic energy {tilde over (P)}(x_i,t₁,t₂)over a time interval from t₁ to t₂ at a plurality of locations x_i of transducers; and

(Two) determining an average acoustic energy {tilde over (P)}(x, t₁, t₂) at at least one location x by interpolation of the determined {tilde over (P)}(x,t₁,t₂)

21. The method according to claim 20 wherein an average acoustic energy {tilde over (P)}(x,t₁,t₂) is determined over a time interval from t₁ to t₂ a at a plurality of locations of transducers using the algebraic expression:

22. The method according to claim 20 wherein an average acoustic energy is determined at at least one location x by interpolation of the determined {tilde over (P)}(x,t₁,t₂) using the algebraic expression:

23. The method according to claim 22 wherein g(x,x_i,σ

) is the kernel

24. An image of a two-dimensional representation of P produced by the method of claim 16.

25. The method according to claim 15 comprising determining an average acoustic energy over a plurality of successive time intervals, each average acoustic energy being determined using an algorithm involving at least one of the signals P(x_i,t) further comprising sequentially displaying on a display device a representation of each determined average acoustic energy.

26. The method according to claim 15 further comprising, for each of one or more frequency bands:

(One) subjecting the signals P(x_i,t) to band pass filtering in the frequency band; and

(Two) determining an average acoustic energy function for the frequency band based upon at least one of the filtered signals.

27. The method according to claim 26 further comprising displaying on a display device one or more of the acoustic energy functions determined for a frequency band.

28. Use of the method of claim 15 for diagnosing a respiratory tract disorder.

30. A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for determining for at least one time interval, an average acoustic energy function {tilde over (P)} using an algorithm involving at least one signal P(x_i,t) indicative of pressure waves at a location x_i on a body surface.

31. A computer program product comprising a computer useable medium having computer readable program code embodied therein analyzing sounds in at least a portion of an individual'"'"'s body, the computer program product comprising:

computer readable program code for causing the computer to determine, for at least one time interval, an acoustic energy function {tilde over (P)}, {tilde over (P)} being determined in algorithm involving at least one signal P(x_i,t) indicative of pressure waves at a location x_i on a body surface.