Sensor for detecting air flow

• US 20050155602A1
• Filed: 01/21/2004
• Published: 07/21/2005
• Est. Priority Date: 01/21/2004
• Status: Active Grant

• Current Assignee: Battelle Memorial Institute
• Original Assignee: Battelle Memorial Institute
• Inventors: Lipp, Brian A.
• Granted Patent: US 7,607,435 B2
• Time in Patent Office: Days
• US Class Current: 128/203.120
• CPC Class Codes: A61M 15/0065 Inhalators with dosage or measuring devices A61M15/0028 takes precedence; dosage devices incorporated in aerosol cans B65D83/52
• CPC Class Codes: A61M 15/02 with activated or ionised fluids, e.g. electrohydrodynamic [EHD] or electrostatic devices; Ozone-inhalators with radioactive tagged particles
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: G01F 1/28 by drag-force, e.g. vane type or impact flowmeter

Abstract

An air flow sensor comprises a flexible resistive element permanently affixed to a flexible substrate. The air flow sensor is positioned in an inlet for airway to be monitored such that the sensor covers the inlet at all times other than during inhalation. When a vacuum is applied to the airway, a resulting drop in air pressure within the airway causes air to flow through the inlet and airway, causing the sensor'"'"'s substrate to flex. Flexure of the substrate also causes a resistive element to flex, resulting in a change in the electrical resistance of the resistive element, such as an increase in resistance. Flexure of the sensor is enhanced by flexible leads, which serve as a hinge point. An air shield may be positioned around the periphery of the air flow sensor to channel and restrict the movement of air flowing through the air inlet, thereby enhancing movement of the sensor.

Claims

1. A sensor for detecting movement of air, comprising:

a) a flexible substrate;

b) a flexible transducer affixed to the substrate, the transducer comprising a first end and a second end;

c) a first electrical contact in electrical communication with the first end of the transducer;

d) a second electrical contact in electrical communication with the second end of the transducer;

e) a protective covering placed over at least a portion of at least one of the transducer, first electrical contact and second electrical contact; and

f) wherein the substrate is displaced when positioned in a stream of moving air, the displacement of the substrate causing flexure of the transducer and changing the electrical value of the transducer.

2. A sensor according to claim 1 wherein the protective covering substantially covers the flexible transducer.

3. A sensor according to claim 1 wherein the protective covering substantially covers the flexible transducer and the first and second electrical contacts.

4. A sensor according to claim 1 wherein the protective covering is a conformal coating.

5. A sensor according to claim 1 wherein the flexible transducer comprises a resistive ink.

6. A sensor according to claim 1, further comprising at least one flexible lead integral to the substrate.

7. A sensor according to claim 6 wherein the flexible transducer is affixed to the flexible lead.

8. A sensor according to claim 1 wherein:

a) the flexible substrate comprises a first side and a second side;

b) the first and second electrical contacts are affixed to the first side of the flexible substrate;

c) a third electrical contact is affixed to the second side of the flexible substrate, aligned with the first electrical contact, and is in electrical communication with the first electrical contact; and

d) a fourth electrical contact is affixed to the second side of the flexible substrate, aligned with the second electrical contact, and is in electrical communication with the second electrical contact.

9. A sensor according to claim 8 wherein:

a) the first electrical contact is in electrical communication with the third electrical contact by means of a plated-through hole extending between the first and third electrical contact; and

b) the second electrical contact is in electrical communication with the fourth electrical contact by means of a plated-through hole extending between the second and fourth electrical contact.

10. A sensor according to claim 8 wherein:

a) the first electrical contact is in electrical communication with the third electrical contact by means of a via extending between the first and third electrical contact; and

b) the second electrical contact is in electrical communication with the fourth electrical contact by means of a via extending between the second and fourth electrical contact.

11. A sensor according to claim 1, further comprising an air inlet-covering portion.

12. A sensor according to claim 11 wherein the inlet-covering portion is generally rectangular in shape.

13. A sensor according to claim 1, further comprising a mounting portion.

14. A sensor according to claim 13 wherein the first and second electrical contacts are affixed to the mounting portion.

15. A sensor according to claim 1 wherein the electrical value of the flexible transducer changes in proportion to the flexure of the flexible substrate.

16. A sensor according to claim 1 wherein the electrical value of the flexible transducer changes from a lower electrical value to a higher electrical value when the flexible substrate is flexed.

17. A sensor according to claim 1 wherein the flexible substrate is made of polyimide.

18. A sensor according to claim 1 wherein the sensor is positioned in the stream of moving air such that the sensor acts as a one-way valve.

19. A sensor for detecting inhalation, comprising:

a) a flexible substrate;

b) a flexible transducer affixed to the substrate, the transducer comprising a first end and a second end;

c) a first electrical contact in electrical communication with the first end of the transducer;

d) a second electrical contact in electrical communication with the second end of the transducer;

e) a protective covering placed over at least a portion of at least one of the transducer, first electrical contact and second electrical contact; and

f) wherein the substrate is displaced when positioned in a stream of moving air caused by inhalation, the displacement of the substrate causing flexure of the transducer and changing the electrical value of the transducer.

20. A sensor according to claim 19 wherein the protective covering substantially covers the flexible transducer.

21. A sensor according to claim 19 wherein the protective covering substantially covers the flexible transducer and the first and second electrical contacts.

22. A sensor according to claim 19 wherein the flexible transducer comprises a resistive ink.

23. A sensor according to claim 19, further comprising at least one flexible lead integral to the substrate.

24. A sensor according to claim 19 wherein the flexible transducer is affixed to the flexible lead.

25. A sensor according to claim 19 wherein:

a) the flexible substrate comprises a first side and a second side;

b) the first and second electrical contacts are affixed to the first side of the flexible substrate;

c) a third electrical contact is affixed to the second side of the flexible substrate, aligned with the first electrical contact, and is in electrical communication with the first electrical contact; and

d) a fourth electrical contact is affixed to the second side of the flexible substrate, aligned with the second electrical contact, and is in electrical communication with the second electrical contact.

26. A sensor according to claim 25 wherein:

a) the first electrical contact is in electrical communication with the third electrical contact by means of a plated-through hole extending between the first and third electrical contact; and

b) the second electrical contact is in electrical communication with the fourth electrical contact by means of a plated-through hole extending between the second and fourth electrical contact.

27. A sensor according to claim 25 wherein:

a) the first electrical contact is in electrical communication with the third electrical contact by means of a via extending between the first and third electrical contact; and

b) the second electrical contact is in electrical communication with the fourth electrical contact by means of a via extending between the second and fourth electrical contact.

28. A sensor according to claim 19, further comprising an air inlet-covering portion.

29. A sensor according to claim 19, further comprising a mounting portion.

30. A sensor according to claim 29 wherein the first and second electrical contacts are affixed to the mounting portion.

31. A sensor according to claim 19 wherein the electrical value of the flexible transducer changes in proportion to the flexure of the flexible substrate.

32. A sensor according to claim 19 wherein the electrical value of the flexible transducer changes from a lower electrical value to a higher electrical value when the flexible substrate is flexed.

33. A sensor according to claim 19 wherein the sensor is positioned in the stream of moving air such that the sensor acts as a one-way valve.

34. A sensor for detecting movement of air, comprising:

a) a flexible substrate;

b) at least one flexible lead integral to the substrate;

c) a flexible resistive ink transducer affixed to the flexible lead, the transducer comprising a first end and a second end;

d) a first electrical contact in electrical communication with the first end of the transducer;

e) a second electrical contact in electrical communication with the second end of the transducer;

f) a protective covering placed over at least a portion of at least one of the transducer, first electrical contact and second electrical contact; and

g) wherein the substrate is displaced when positioned in a stream of moving air, the displacement of the substrate causing flexure of the transducer and changing the electrical value of the transducer.

35. A device for delivering medication, comprising:

a) an air inlet;

b) an airway in pneumatic communication with the air inlet;

c) a sensor for detecting movement of air, the sensor being positioned in the airway proximate the air inlet such that the sensor is effective to selectively close the air inlet;

d) a reservoir for containing medication;

e) a pump/valve in pneumatic communication with the reservoir;

f) an aerosolation spray means in pneumatic communication with the pump/valve;

g) a mouthpiece in pneumatic communication with the airway and the aerosolation spray means;

h) an electrical power supply;

i) a controller portion in electrical communication with the power supply, sensor, pump/valve and aerosolation means; and

j) wherein;

i) air flowing into the airway from the air inlet displaces the sensor, changing the electrical value of the sensor;

ii) the controller portion detects the change in electrical value of the sensor and actuates the pump/valve;

iii) the pump/valve urges medication to flow from the reservoir to the aerosolation means;

iv) the aerosolation means aerosolizes the medication; and

v) wherein the air flowing into the airway is combined with the aerosolized medication in the mouthpiece for delivery to a patient.

36. A device according to claim 35 wherein the sensor is placed in electrical communication with the controller portion by means of at least one rivet.

37. A device according to claim 35 wherein the sensor is placed in electrical communication with the controller portion by means of conductive adhesive.

38. A device according to claim 35, further comprising an air shield positioned proximate the sensor to direct the air flowing into the airway from the air inlet toward the sensor.

39. A device according to claim 35 wherein the sensor cooperates with the air inlet to act as a one-way valve.

40. A device for delivering medication, comprising:

a) an air inlet;

b) an airway in pneumatic communication with the air inlet;

c) a sensor for detecting movement of air, the sensor being positioned in the airway proximate the air inlet such that the sensor is effective to selectively close the air inlet;

d) a reservoir for containing medication;

e) a pump/valve in pneumatic communication with the reservoir;

f) an electrohydrodynamic aerosolation spray means in pneumatic communication with the pump/valve;

g) a mouthpiece in pneumatic communication with the airway and the electrohydrodynamic aerosolation spray means;

h) an electrical power supply;

i) a controller portion in electrical communication with the power supply, sensor, pump/valve and electrohydrodynamic aerosolation means; and

j) wherein;

i) air flowing into the airway from the inlet displaces the sensor, changing the electrical value of the sensor;

ii) the controller portion detects the change in electrical value of the sensor and actuates the pump/valve;

iii) the pump/valve urges medication to flow from the reservoir to the electrohydrodynamic aerosolation means;

iv) the electrohydrodynamic aerosolation means aerosolizes the medication; and

v) wherein the air flowing into the airway is combined with the aerosolized medication in the mouthpiece for delivery to a patient.

41. A device according to claim 40 wherein the sensor is placed in electrical communication with the controller portion by means of at least one rivet.

42. A device according to claim 40 wherein the sensor is placed in electrical communication with the controller portion by means of conductive adhesive.

43. A device according to claim 40, further comprising an air shield positioned proximate the sensor to direct the air flowing into the airway from the air inlet toward the sensor.

44. A device according to claim 40 wherein the sensor cooperates with the air inlet to act as a one-way valve.