Method and system of scoring sleep disordered breathing

• US 20060060198A1
• Filed: 09/14/2005
• Published: 03/23/2006
• Est. Priority Date: 09/17/2004
• Status: Abandoned Application

• Current Assignee: Acoba LLC
• Original Assignee: Acoba LLC
• Inventors: Aylsworth, Alonzo C., Spector, Lawrence C.
• Application Number:
  US11/226,570
• Publication Number:
  US 20060060198A1
• Time in Patent Office: Days
• US Class Current: 128/204.230
• CPC Class Codes: A61B 2560/0475 Special features of memory means, e.g. removable memory cards
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/0878 using temperature sensing means
• CPC Class Codes: A61B 5/1135 by monitoring thoracic expansion
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/021 operated by electrical means A61M16/202 – A61M16/205 take precedence
• CPC Class Codes: A61M 2230/04 Heartbeat characteristics, e.g. ECG, blood pressure modulation
• CPC Class Codes: A61M 2230/63 Motion, e.g. physical activity

Abstract

A method and system of scoring sleep disordered breathing. At least some of the illustrative embodiments are a method comprising sensing an attribute of respiratory airflow of a first breath of a patient, converting the attribute to a volume value proportional to the volume of the air respired by the patient, and determining whether the patient experienced a hypopnea or an apnea by comparing the volume value to a reference value created using a value proportional to the volume of a breath preceding the first breath.

Claims

1. A method comprising:

sensing an attribute of respiratory airflow of a first breath of a patient;

converting the attribute to a volume value proportional to the volume of the air respired by the patient; and

determining whether the patient experienced a hypopnea or an apnea by comparing the volume value to a reference value created using a value proportional to the volume of a breath preceding the first breath.

2. The method as defined in claim 1 further comprising:

wherein sensing further comprises sensing airflow rate using a mass flow sensor fluidly coupled within the airflow of a breathing orifice of the patient to create a sensed airflow signal; and

wherein converting further comprises calculating the volume value from the sensed airflow signal.

5. The method as defined in claim 1 further comprising:

wherein sensing further comprises sensing pressure using a pressure transducer fluidly coupled to a breathing orifice of the patient to create a pressure output signal; and

wherein converting further comprises calculating the volume value from the pressure output signal.

6. The method as defined in claim 5 wherein calculating further comprises determining an area between the pressure output signal and an axis at zero gauge pressure.

7. The method as defined in claim 5 wherein calculating further comprises determining an area between the pressure output signal during inhalation and the axis at zero gauge pressure.

8. The method as defined in claim 1 further comprising:

wherein sensing further comprises sensing temperature using a temperature sensing device fluidly coupled within the airflow of a breathing orifice of the patient to create a temperature output signal; and

wherein converting further comprises calculating the volume value from the pressure output signal.

9. The method as defined in claim 8 wherein calculating further comprises determining an area between the temperature output signal and an axis at a peak measured temperature.

10. The method as defined in claim 8 wherein calculating further comprises determining an area between the temperature output signal during inhalation and the axis being a highest exhalation temperature.

11. The method as defined in claim 8 further comprising sensing using one device selected from the group:

a thermocouple;

a thermal resistor; and

a piezoelectric device.

12. The method as defined in claim 1 wherein determining further comprises:

producing a reference bar waveform having an amplitude and a time width, wherein the amplitude is proportional to the reference value;

producing a scoring bar waveform having an amplitude and a time width, wherein the amplitude of the scoring bar is proportional to the volume value; and

ascertaining a difference in amplitude between the scoring bar waveform and the reference bar waveform.

13. The method as defined in claim 12 wherein producing the scoring bar further comprises producing the scoring bar wherein time width is one selected from the group:

a predetermined constant, the period of a breath of the patient, the patient'"'"'s blood-oxygen saturation, and the patient'"'"'s breath rate.

14. The method as defined in claim 12 wherein producing the reference bar waveform further comprising producing the reference bar waveform with the amplitude proportional to an average volume of a plurality of breaths preceding the first breath.

15. The method as defined in claim 12 wherein producing the reference bar waveform further comprises producing the reference bar waveform wherein the time width is one selected from the group:

a predetermined constant, frequency of a snore component of the patient'"'"'s breathing, and amplitude of the snore component of the patient'"'"'s breathing.

3. The method as defined 2 wherein calculating further comprises determining the area between the sensed airflow signal and an axis at zero flow.

4. The method as defined 2 wherein calculating further comprises determining the area between the sensed airflow signal during inhalation and the axis at zero flow.

16. A system comprising:

a processor;

a memory coupled to the processor; and

a first sensor that senses an attribute of airflow electrically coupled to the processor, the first sensor in operational relationship to a first breathing orifice of a patient;

a second sensor that senses an attribute of airflow electrically coupled to the processor, the second sensor in operational relationship to a second breathing orifice of the patient;

wherein the processor calculates a first volume value based on a signal from the first sensor during a first breath, the first volume value proportional to air volume through the first breathing orifice during the first breath; and

wherein the processor calculates a second volume value based on a signal from the second sensor during the first breath, the second volume value proportional to air volume through the second breathing orifice during the first breath.

17. The system as defined in claim 16 wherein the processor calculates a breath volume value based on the first and second volume values.

18. The system as defined in claim 17 wherein the processor determines whether the patient experienced a hypopnea or an apnea by comparison of the breath volume to a previous breath volume calculated using a value proportional to air volume of a previous breath.

19. The system as defined in claim 18 further comprising:

a blood oxygen input signal electrically coupled to the processor, the blood oxygen input signal couples to a blood oxygen sensor that senses blood oxygen saturation of the patient;

wherein the processor uses a blood oxygen saturation value to determine whether the patient experienced a hypopnea or an apnea during the plurality of breaths.

20. The system as defined in claim 17 further comprising:

wherein the memory is selectively detachable from the system; and

wherein the processor writes an indication to the memory if a hypopnea or apnea was sensed.

21. The system as defined in claim 17 wherein the processor generates a scoring bar signal having an amplitude proportional to the breath volume value.

22. The system as define din claim 21 wherein the processor generates the scoring bar signal having a time width being one selected from the group:

a predetermined constant, the period of a breath of the patient, the patient'"'"'s blood-oxygen saturation, and the patient'"'"'s breath rate.

23. The system as defined in claim 21 wherein the processor also generates a reference bar signal having an amplitude proportional to air volume of a previous breath.

24. The system as defined in claim 23 wherein the processor generates the reference bar signal having a time width being one selected from the group:

a predetermined constant, frequency of a snore component of the patient'"'"'s breathing, and amplitude of the snore component of the patient'"'"'s breathing.

25. The system as defined in claim 21 further comprising:

an output signal port coupled to the processor;

wherein the processor drives the scoring bar signal to the output signal port.

26. The system as defined in claim 25 wherein the output signal port is an analog output signal port.

27. The system as defined in claim 21 further comprising:

a display device coupled to the processor; and

wherein the processor drives the scoring bar signal to the display device.

28. The system as defined in claim 21 further comprising:

wherein the memory is selectively detachable from the system; and

wherein the processor provides the breath volume to other devices by writing the first and second volume values to the detachable memory.

29. The system as defined in claim 17 further comprising:

wherein the first sensor is a first air mass flow sensor that fluidly couples to the first naris of the patient;

wherein the second sensor is a second air mass flow sensor that fluidly couples to a second naris of the patient;

wherein the processor determines a breath volume based on signals from both the first and second air mass flow sensor.

30. The system as defined in claim 29 further comprising:

a third air mass flow sensor electrically coupled to the processor, the third air mass flow sensor fluidly couples to the patient'"'"'s mouth;

wherein the processor determines the breath volume based on signals from the first, second and third air mass flow sensors.

31. The system as defined in claim 17 further comprising:

wherein the memory is selectively detachable from the system; and

wherein the processor provides the first and second volume values to other devices by writing the first and second volume values to the detachable memory.