Method and apparatus for monitoring respiration

• US 20020072685A1
• Filed: 12/13/2000
• Published: 06/13/2002
• Est. Priority Date: 12/13/2000
• Status: Active Grant

• Current Assignee: GE Marquette Medical Systems, Inc. (General Electric Company)
• Original Assignee: GE Medical Systems Information Technologies Incorporated (General Electric Company)
• Inventors: Rymut, Russell, Kini, Narendra, Slotty, Eric
• Granted Patent: US 6,517,497 B2
• Time in Patent Office: Days
• US Class Current: 600/529
• CPC Class Codes: A61B 2562/0204 Acoustic sensors
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/6822 Neck
• CPC Class Codes: A61B 5/6833 Adhesive patches

Abstract

A method and apparatus for monitoring and/or quantitatively measuring a patient'"'"'s respiration using a flexible piezoelectric film sensor. The apparatus includes a piezoelectric film which converts acoustical waves generated by the patient'"'"'s respiration into electrical signals. The piezoelectric film sensor can be used to monitor the respiration of a patient by correlating the sound generated in the patient'"'"'s airway with respiratory activity. Further, the data generated by the sensor may be further analyzed by a patient monitor to diagnose respiratory conditions.

Claims

1. A respiration sensor comprising:

a substrate; and

a piezoelectric film mounted on the substrate so that force applied to the sensing region in response to respiration generates a charge on the piezoelectric film.

2. The respiration sensor of claim 1 wherein the substrate includes a connector portion and conductors on the connector portion.

3. The respiration sensor of claim 1 wherein the substrate includes a sensing region and wherein the sensing region includes:

a base portion;

a film ear; and

a contact ear.

4. The respiration sensor of claim 3 wherein the piezoelectric film is mounted on the film ear.

5. The respiration sensor of claim 3 wherein the base portion includes a base ring mounted on the base portion and foam mounted within the base ring on the base portion.

6. The respiration sensor of claim 3 wherein the contact ear is folded over the base portion and the film ear is folded over the contact ear providing a layered disposition of base portion, contact ear and film ear and wherein the base portion, contact ear and film ear are bonded together using electrically conductive adhesive.

7. The respiration sensor of claim 1 wherein the substrate includes a first sensing region and the first piezoelectric film is mounted on the substrate adjacent the first sensing region, and the substrate further includes a second sensing region and second piezoelectric film mounted on the substrate adjacent the second sensing region.

8. The respiration sensor of claim 7 wherein the substrate includes a center connecting portion connecting the sensing regions.

9. The respiration sensor of claim 8 wherein the connecting portion includes a patient monitor interface.

10. The respiration sensor of claim 7 wherein at least a one of the first and second sensing regions has a trapezoidal shape.

11. The respiration sensor of claim 1 wherein the piezoelectric film has a trapezoidal shape.

12. The respiration sensor of claim 1 wherein the force is an acoustical vibration generated by a patient during respiration.

14. The respiration sensor of claim 13 wherein the piezoelectric films have a trapezoidal shape.

16. The patient monitor of claim 15 wherein the sensor includes a connecting portion having electrical conductors mounted on the connecting portion.

17. The patient monitor of claim 15 wherein the respiration sensor includes a piezoelectric film configured and arranged to detect acoustical vibrations generated during respiration.

18. The patient monitor of claim 15 wherein the respiration sensor includes a sensing region having:

a base portion;

a film ear; and

a contact ear.

19. The patient monitor of claim 18 wherein the respiration sensor includes piezoelectric film mounted on the film ear.

20. The patient monitor of claim 18 wherein the base portion includes a base ring mounted on the base portion and foam mounted within the base ring on the base portion.

21. The patient monitor of claim 18 wherein the contact ear of said respiration sensor said is folded over said base portion and said film ear is folded over said contact ear providing a layered disposition of base portion, contact ear and film ear.

22. The patient monitor of claim 15 including a second respiration sensor having a second sensing region and second piezoelectric film mounted on the second sensing region.

23. The patient monitor of claim 15 wherein the respiration sensor includes a connecting portion and electrical conductors mounted on the connecting portion to provide a patient monitoring interface.

24. The patient monitor of claim 21 wherein the base portion, contact ear and film ear of respiration sensor are bonded together using electrically conductive adhesive.

25. The patient monitor of claim 15 including:

an amplifier for amplifying the signal produced by the sensor;

a signal processor for measuring variations of the signal and converting the variations into a value corresponding to a physiological characteristic; and

a display for displaying said value.

26. The patient monitor of claim 15 including an adaptive noise canceling filter for removing non-respiratory acoustic vibrations.

27. The patient monitor of claim 26 wherein the sensor generates a noise reference signal for use by the adaptive noise canceling filter.

28. The patient monitoring apparatus of claim 15 wherein the sensor includes a foam material with a convex radius for transforming acoustical vibrations perpendicular to the piezoelectric film into longitudinal acoustical vibrations.

30. The method of claim 29 including the additional act of removing non-respiratory acoustical vibrations using an adaptive noise cancellation filter.

31. The method of claim 30 wherein the additional act of removing non-respiratory acoustical vibrations using an adaptive noise cancellation filter includes independently sampling noise reference signals and using a computer processor containing an adaptive noise cancellation algorithm to minimize mechanically coupled interference from the sensor.

13. A patient monitoring apparatus comprising:

a flexible substrate including a backing layer and a circuit layer having exposed metal contacts, said flexible substrate including;

a first sensing region having;

a rigid base ring mounted on the substrate;

a convex foam material layer mounted on the substrate within the base ring;

a contact ear connected to the flexible substrate via substrate hinges and being folded over at the hinges so as to rest on the rigid base ring; and

a film ear connected to the flexible substrate via substrate hinges and being folded over at the hinges so as to rest on the contact ear, the film ear including a first piezoelectric film layer mounted on the film ear;

a second sensing region including;

a rigid base ring mounted on the substrate;

a convex foam material layer mounted on the substrate within the base ring;

a contact ear connected to the flexible substrate via substrate hinges and being folded over at the hinges so as to rest on the rigid base ring; and

a film ear connected to the flexible substrate via substrate hinges and being folded over at the hinges so as to rest on the contact ear, the film ear including a first piezoelectric film layer mounted on the film ear;

a patient monitor interface connecting the first and second sensing regions and having electrically conductive contacts for providing an electrical connection between the piezoelectric films and a patient monitor.

15. A patient monitor comprising:

a piezoelectric signal acquisition unit;

a respiration sensor connected to the signal acquisition unit.

29. A method of monitoring the respiration of a patient, said method comprising the acts of:

placing a piezoelectric sensor on the patient;

monitoring acoustical vibrations generated by respiration of the patient;

providing a value correlating to respiratory activity of the patient based on the acoustical vibrations.

32. A method of diagnosing respiratory conditions in a patient, said method comprising the acts of:

placing a piezoelectric sensor on the patient;

monitoring acoustical vibrations generated by respiration of the patient using the piezoelectric sensor;

generating a value correlating to respiratory activity of said patient based on the acoustical vibrations; and

comparing the value correlating to the respiratory activity of the patient with known values corresponding to known respiratory conditions.

33. The method of claim 32 wherein the method is achieved using a computer processor to monitor acoustical respiratory data received by the sensor, using a computer processor to compare the data from the patient to known values corresponding to known respiratory conditions thereby predicting the presence of respiratory conditions associated with the existence of specific acoustical respiratory data.

35. An apparatus according to claim 34, wherein the sensor is operatively coupled to said patient monitor via a cable.

36. An apparatus according to claim 34, wherein the sensor includes a wireless transmitter to transmit the signal to the patient monitor and wherein the patient monitor further includes a receiver configured and adapted to receive said signal.

34. A patient monitoring apparatus comprising:

at least one sensor element for transforming acoustical vibrations associated with inhalation and exhalation into electrical signals, said signals reflecting the flow of air through an airway of user; and

a patient monitor for receiving said signals and determining a quantitative value for a respiratory characteristic of a user based on said signals.