System and method for monitoring a respiration rate of an occupant of a predetermined volume

• US 20060009703A1
• Filed: 07/08/2004
• Published: 01/12/2006
• Est. Priority Date: 07/08/2004
• Status: Active Grant

• Current Assignee: Aptiv Technologies AG (Aptiv PLC)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Griffin, Dennis P., Fultz, William W.
• Granted Patent: US 7,473,228 B2
• Time in Patent Office: Days
• US Class Current: 600/529
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/113 occurring during breathing
• CPC Class Codes: A61B 5/18 for vehicle drivers or machine operators
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 8/00 Diagnosis using ultrasonic, sonic or infrasonic waves imaging of objects using sonar G01S15/00

Abstract

An ultrasonic sensing system includes an ultrasonic transmitter, an ultrasonic receiver, a processor and a memory subsystem. The transmitter is positioned to transmit an ultrasonic signal into a predetermined volume. The receiver is positioned to receive a composite signal from the predetermined volume. The processor is coupled to the transmitter, the receiver and the memory subsystem. The memory subsystem stores code that when executed by the processor instructs the processor to perform a number of steps to determine whether an occupant is present in the predetermined volume and whether the detected occupant has a respiration rate.

Claims

1. A method for monitoring a respiration rate of an occupant of a predetermined volume, comprising the steps of:

analyzing frequency component amplitudes of a received ultrasonic signal to determine a frequency content of the received ultrasonic signal, wherein the received ultrasonic signal is a composite signal that provides an indication of a respiration rate of an occupant present within a predetermined volume;

determining whether a current peak respiration rate is the same as a previous peak respiration rate;

incrementing a current peak respiration rate counter when the current peak respiration rate is the same as the previous peak respiration rate; and

decrementing a previous peak respiration rate counter when the current peak respiration rate is not the same as the previous peak respiration rate and an amplitude of the current peak respiration rate is a predetermined amount greater than an amplitude of the previous peak respiration rate.

2. The method of claim 1, wherein the previous peak respiration rate counter is also decremented when the current peak respiration rate is not the same as the previous peak respiration rate and the current peak respiration rate corresponds to a respiration rate that is adjacent to the previous peak respiration rate.

3. The method of claim 1, wherein the current peak respiration rate counter and the previous peak respiration rate counter are not altered unless the frequency component amplitudes of the received ultrasonic signal indicate a detected respiration rate and the presence of the occupant in the predetermined volume.

4. The method of claim 1, wherein the current peak respiration rate counter is only incremented if a value of the current peak respiration rate counter is less than a predetermined maximum counter value and the current peak respiration rate is the same as the previous peak respiration rate.

5. The method of claim 2, wherein the previous peak respiration rate counter is only decremented if a value of the previous peak respiration rate counter is more than a predetermined minimum counter value.

6. The method of claim 1, further comprising the steps of:

determining whether amplitudes associated with respiration rates adjacent the current peak respiration rate are within a predetermined value of an amplitude of the current peak respiration rate;

incrementing an adjacent lower respiration rate counter when the amplitude of the adjacent lower respiration rate is within the predetermined value of the amplitude of the current peak respiration rate;

incrementing an adjacent upper respiration rate counter when the amplitude of the adjacent upper respiration rate is within the predetermined value of the amplitude of the current peak respiration rate; and

determining an average respiration rate based on values of the adjacent lower respiration rate counter, the adjacent upper respiration rate counter and current peak respiration rate counter.

7. The method of claim 6, wherein the adjacent lower respiration rate counter is only incremented if a value of the adjacent lower respiration rate counter is less than a predetermined maximum counter value.

8. The method of claim 7, wherein the adjacent upper respiration rate counter is only incremented if a value of the adjacent upper respiration rate counter is less than the predetermined maximum counter value.

9. The method of claim 8, wherein the counters are cleared when the frequency component amplitudes of the received ultrasonic signal indicate that there are no occupants present in the predetermined volume or the occupant does not have a respiration rate.

10. The method of claim 1, wherein the frequency content is between 0 and 3 Hertz.

11. An ultrasonic sensing system, comprising:

an ultrasonic transmitter positioned to transmit an ultrasonic signal into a predetermined volume;

an ultrasonic receiver positioned to receive a composite signal from the predetermined volume;

a processor coupled to the transmitter and the receiver; and

a memory subsystem coupled to the processor, the memory subsystem storing code that when executed by the processor instructs the processor to perform the steps of;

analyzing frequency component amplitudes of a received ultrasonic signal to determine a frequency content of the received ultrasonic signal, wherein the received ultrasonic signal is a composite signal that provides an indication of a respiration rate of an occupant present within a predetermined volume;

determining whether a current peak respiration rate is the same as a previous peak respiration rate;

incrementing a current peak respiration rate counter when the current peak respiration rate is the same as the previous peak respiration rate; and

decrementing a previous peak respiration rate counter when the current peak respiration rate is not the same as the previous peak respiration rate and an amplitude of the current peak respiration rate is a predetermined amount greater than an amplitude of the previous peak respiration rate.

12. The system of claim 11, wherein the previous peak respiration rate counter is also decremented when the current peak respiration rate is not the same as the previous peak respiration rate and the current peak respiration rate corresponds to a respiration rate that is adjacent to the previous peak respiration rate.

13. The system of claim 11, wherein the current peak respiration rate counter and the previous peak respiration rate counter are not altered unless the frequency component amplitudes of the received ultrasonic signal indicate a detected respiration rate and the presence of the occupant in the predetermined volume.

14. The system of claim 11, wherein the current peak respiration rate counter is only incremented if a value of the current peak respiration rate counter is less than a predetermined maximum counter value and the current peak respiration rate is the same as the previous peak respiration rate.

15. The system of claim 12, wherein the previous peak respiration rate counter is only decremented if a value of the previous peak respiration rate counter is more than a predetermined minimum counter value.

16. The system of claim 11, the memory subsystem storing additional code for instructing the processor to perform the additional steps of:

determining whether amplitudes associated with respiration rates adjacent the current peak respiration rate are within a predetermined value of an amplitude of the current peak respiration rate;

incrementing an adjacent lower respiration rate counter when the amplitude of the adjacent lower respiration rate is within the predetermined value of the amplitude of the current peak respiration rate;

incrementing an adjacent upper respiration rate counter when the amplitude of the adjacent upper respiration rate is within the predetermined value of the amplitude of the current peak respiration rate; and

determining an average respiration rate based on values of the adjacent lower respiration rate counter, the adjacent upper respiration rate counter and current peak respiration rate counter.

17. The system of claim 16, wherein the adjacent lower respiration rate counter is only incremented if a value of the adjacent lower respiration rate counter is less than a predetermined maximum counter value.

18. The system of claim 17, wherein the adjacent upper respiration rate counter is only incremented if a value of the adjacent upper respiration rate counter is less than the predetermined maximum counter value.

19. The system of claim 18, wherein the counters are cleared when the frequency component amplitudes of the received ultrasonic signal indicate that there are no occupants present in the predetermined volume or the occupant does not have a respiration rate.

20. The system of claim 11, wherein the frequency content is between 0 and 300 Hertz.

21. An ultrasonic sensing system, comprising:

an ultrasonic transmitter positioned to transmit an ultrasonic signal into a predetermined volume;

an ultrasonic receiver positioned to receive a composite signal from the predetermined volume;

a processor coupled to the transmitter and the receiver; and

a memory subsystem coupled to the processor, the memory subsystem storing code that when executed by the processor instructs the processor to perform the steps of;

analyzing frequency component amplitudes of a received ultrasonic signal to determine a frequency content of the received ultrasonic signal, wherein the received ultrasonic signal is a composite signal that provides an indication of a respiration rate of an occupant present within a predetermined volume;

determining whether a current peak respiration rate is the same as a previous peak respiration rate;

incrementing a current peak respiration rate counter when the current peak respiration rate is the same as the previous peak respiration rate; and

decrementing a previous peak respiration rate counter when the current peak respiration rate is not the same as the previous peak respiration rate and the current peak respiration rate corresponds to a respiration rate that is adjacent to the previous peak respiration rate.

22. The system of claim 21, wherein the previous peak respiration rate counter is also decremented when the current peak respiration rate is not the same as the previous peak respiration rate and an amplitude of the current peak respiration rate is a predetermined amount greater than an amplitude of the previous peak respiration rate.

23. The system of claim 21, wherein the current peak respiration rate counter and the previous peak respiration rate counter are not altered unless the frequency component amplitudes of the received ultrasonic signal indicate a detected respiration rate and the presence of the occupant in the predetermined volume.

24. The system of claim 21, wherein the current peak respiration rate counter is only incremented if a value of the current peak respiration rate counter is less than a predetermined maximum counter value and the current peak respiration rate is the same as the previous peak respiration rate.

25. The system of claim 22, wherein the previous peak respiration rate counter is only decremented if a value of the previous peak respiration rate counter is more than a predetermined minimum counter value.

26. The system of claim 21, the memory subsystem storing additional code for instructing the processor to perform the additional steps of:

determining whether amplitudes associated with respiration rates adjacent the current peak respiration rate are within a predetermined value of an amplitude of the current peak respiration rate;

incrementing an adjacent lower respiration rate counter when the amplitude of the adjacent lower respiration rate is within the predetermined value of the amplitude of the current peak respiration rate;

incrementing an adjacent upper respiration rate counter when the amplitude of the adjacent upper respiration rate is within the predetermined value of the amplitude of the current peak respiration rate; and

determining an average respiration rate based on values of the adjacent lower respiration rate counter, the adjacent upper respiration rate counter and current peak respiration rate counter.

27. The system of claim 26, wherein the adjacent lower respiration rate counter is only incremented if a value of the adjacent lower respiration rate counter is less than a predetermined maximum counter value.

28. The system of claim 27, wherein the adjacent upper respiration rate counter is only incremented if a value of the adjacent upper respiration rate counter is less than the predetermined maximum counter value.

29. The system of claim 28, wherein the counters are cleared when the frequency component amplitudes of the received ultrasonic signal indicate that there are no occupants present in the predetermined volume or the occupant does not have a respiration rate.

30. The system of claim 21, wherein the frequency content is between 0 and 3 Hertz.