Portable air sampling systems including non-intrusive activity monitor and methods of using same

• US 6,105,440 A
• Filed: 03/16/1999
• Issued: 08/22/2000
• Est. Priority Date: 03/16/1999
• Status: Expired due to Term

• Current Assignee: Research Triangle Institute
• Original Assignee: Research Triangle Institute
• Inventors: Lawless, Philip A.
• Primary Examiner(s): RAEVIS, ROBERT R
• Application Number:
  US09/268,761
• Time in Patent Office: 525 Days
• Field of Search: 73/863.01, 73/863.21, 73/863.23, 73/864.34
• US Class Current: 73/863.21
• CPC Class Codes: G01N 1/2273 Atmospheric sampling
• CPC Class Codes: G01N 2001/021 Correlating sampling sites with geographical information, e.g. GPS
• CPC Class Codes: G01N 2001/2276 Personal monitors

Abstract

Portable air sampling systems and methods are provided for intermittently sampling air in the breathing zone of a person over extended periods of time. Air sampling system performance can be continuously measured and recorded within a data logger. In addition, physical activity levels of a person wearing a portable air sampling system can be continuously monitored and recorded within the data logger. Air sampling system performance monitoring includes measuring pressure drop across a filter and measuring temperature of air flowing through the filter. Physical activity levels of a person can be monitored easily and non-intrusively by measuring changes in electrical capacitance of a transducer maintained in close proximity to the person.

Claims

1. A portable air sampling system for sampling air from a breathing zone of a creature, comprising:

a filter device, comprising;

a housing including an air inlet in communication with the breathing zone, and an air outlet; and

a filter element disposed within the housing that is configured to retain particles entrained within air flowing therethrough;

a pump in fluid communication with the filter device air outlet, wherein the pump is configured to draw a predetermined volume of air into the filter device and through the filter element;

means for intermittently activating the pump to draw the predetermined volume of air through the filter element at predetermined intervals;

means for monitoring performance of the air sampling system; and

means for monitoring physical activity of the creature, comprising;

a transducer configured to change electrical capacitance in response to physical activity of the creature; and

a data logger that records changes in electrical capacitance of the transducer.

2. A system according to claim 1 wherein the pump activating means comprises:

an electrical motor;

a power supply that supplies electrical power to the electrical motor; and

a timing circuit that interrupts the supply of electrical power to the electrical motor at the predetermined intervals.

3. A system according to claim 2 wherein the means for monitoring performance of the air sampling system comprises:

means for continuously measuring voltage across the power supply; and

means for recording power supply voltage data within the data logger.

4. A system according to claim 1 wherein the means for monitoring performance of the air sampling system comprises:

means for continuously measuring pressure drop across the filter; and

means for recording measured pressure drop data within the data logger.

5. A system according to claim 1 wherein the means for monitoring performance of the air sampling system comprises:

means for continuously measuring temperature of air drawn into the filter device; and

means for recording air temperature data within the data logger.

6. A system according to claim 1 wherein the transducer comprises at least two adjacent capacitor plates configured to change electrical capacitance in response to a change in distance from each plate to a body of a creature.

7. A system according to claim 1 wherein the creature is a human being.

8. A portable air sampling system for sampling air from a breathing zone of a creature, comprising:

a pack;

means for retaining the pack on the creature;

a filter device mounted externally to the pack, comprising;

a housing including an air inlet in communication with the breathing zone, and an air outlet; and

a filter element disposed within the housing that is configured to retain particles entrained within air flowing therethrough;

a pump disposed within the pack and in fluid communication with the filter device air outlet, wherein the pump is configured to draw a predetermined volume of air into the filter device and through the filter element;

means for intermittently activating the pump to draw the predetermined volume of air through the filter element at predetermined intervals, wherein the activating means is disposed within the pack;

means for monitoring performance of the air sampling system, wherein the performance monitoring means is disposed within the pack; and

means for monitoring physical activity of the creature, wherein the activity monitoring means is disposed within the pack, comprising;

a transducer configured to change electrical capacitance in response to physical activity of the creature; and

a data logger that records changes in electrical capacitance of the transducer.

9. A system according to claim 8 wherein the pump activating means comprises:

an electrical motor;

a power supply that supplies electrical power to the electrical motor; and

a timing circuit that interrupts the supply of electrical power to the electrical motor at the predetermined intervals.

10. A system according to claim 9 wherein the means for monitoring performance of the air sampling system comprises:

means for continuously measuring voltage across the power supply; and

means for recording power supply voltage data within the data logger.

11. A system according to claim 8 wherein the means for monitoring performance of the air sampling system comprises:

means for continuously measuring pressure drop across the filter; and

means for recording measured pressure drop data within the data logger.

12. A system according to claim 8 wherein the means for monitoring performance of the air sampling system comprises:

means for continuously measuring temperature of air drawn into the filter device; and

means for recording air temperature data within the data logger.

13. A system according to claim 8 wherein the transducer comprises at least two adjacent capacitor plates configured to change electrical capacitance in response to a change in distance from each plate to a body of the creature wearing the pack.

14. A system according to claim 8 wherein the pack is a fanny pack.

15. A system according to claim 8 wherein the creature is a human being.

16. A system according to claim 15 wherein the means for monitoring performance of the air sampling system comprises:

means for continuously measuring pressure drop across the filter; and

means for recording measured pressure drop data within the data logger.

17. A system according to claim 15 wherein the means for monitoring performance of the air sampling system comprises:

means for continuously measuring temperature of air drawn into the filter device; and

means for recording air temperature data within the data logger.

18. A system according to claim 15 wherein the means for monitoring performance of the air sampling system comprises:

means for continuously measuring voltage across the power supply; and

means for recording power supply voltage data within the data logger.

19. A system according to claim 15 wherein the pack is a fanny pack.

20. A system according to claim 15 wherein the creature is a human being.

21. A portable air sampling system for sampling air from a breathing zone of a creature, comprising:

a pack;

means for retaining the pack on the creature;

a filter device mounted externally to the pack, comprising;

a housing including an air inlet in communication with the breathing zone, and an air outlet; and

a filter element disposed within the housing that is configured to retain particles entrained within air flowing therethrough;

a pump disposed within the pack and in fluid communication with the filter device air outlet, wherein the pump is configured to draw a predetermined volume of air into the filter device and through the filter element;

means for intermittently activating the pump to draw the predetermined volume of air through the filter element at predetermined intervals, wherein the activating means is disposed within the pack, comprising;

an electrical motor;

a power supply that supplies electrical power to the electrical motor; and

a timing circuit that interrupts the supply of electrical power to the electrical motor at the predetermined intervals;

means disposed within the pack for monitoring performance of the air sampling system;

means for monitoring physical activity of the creature, wherein the activity means is disposed within the pack, comprising;

a plurality of capacitor plates configured to change electrical capacitance in response to a change in distance from each plate to a body of the creature wearing the apparatus; and

means for recording changes in electrical capacitance of the capacitor plates within a data logger.

22. A portable air sampling system for sampling air from a breathing zone of a creature, comprising:

a pack;

means for retaining the pack on the creature;

a filter device mounted externally to the pack, comprising;

a housing including an air inlet in communication with the breathing zone, and an air outlet; and

a filter element disposed within the housing that is configured to retain particles entrained within air flowing therethrough;

a pump disposed within the pack and in fluid communication with the filter device air outlet, wherein the pump is configured to draw a predetermined volume of air into the filter device and through the filter element;

means for intermittently activating the pump to draw the predetermined volume of air through the filter element at predetermined intervals, wherein the activating means is disposed within the pack;

means for monitoring performance of the air sampling system, wherein the performance monitoring means is disposed within the pack, comprising;

means for continuously measuring pressure drop across the filter;

means for recording measured pressure drop data within the data logger;

means for continuously measuring temperature of air drawn into the filter device;

means for recording air temperature data within the data logger; and

means for monitoring physical activity of the creature in real time, wherein the activity monitoring means is disposed within the pack, comprising;

a plurality of capacitor plates configured to change electrical capacitance in response to a change in distance from each plate to a body of the creature wearing the apparatus; and

means for recording changes in electrical capacitance of the capacitor plates within the data logger.

23. A system according to claim 22 wherein the pump activating means comprises:

an electrical motor;

a power supply that supplies electrical power to the electrical motor; and

a timing circuit that interrupts the supply of electrical power to the electrical motor at the predetermined intervals.

24. A system according to claim 22 wherein the pack is a fanny pack.

25. A system according to claim 22 wherein the creature is a human being.

26. A method of sampling air, comprising the steps of:

intermittently sampling air from a breathing zone of a creature, wherein air from the breathing zone is drawn through a filter via a pump;

monitoring pressure drop across the filter during the air sampling step;

monitoring physical activity of the creature during the air sampling step, comprising the step of measuring changes in electrical capacitance of a transducer maintained in close proximity to the creature; and

recording measured pressure drop data and changes in electrical capacitance of the transducer.

27. A method according to claim 26 further comprising the step of measuring temperature of air drawn through the filter during the air sampling step.

28. A method according to claim 26 wherein the step of measuring changes in electrical capacitance of a transducer maintained in close proximity to the creature comprises measuring changes in electrical capacitance of a plurality of adjacent capacitor plates in response to a change in distance from each plate to the creature.

29. A method according to claim 26 wherein the creature is a human being.