BREATH SELECTION FOR ANALYSIS

• US 20140194703A1
• Filed: 01/08/2014
• Published: 07/10/2014
• Est. Priority Date: 01/08/2013
• Status: Active Grant

• Current Assignee: Capnia, Inc.
• Original Assignee: Capnia, Inc.
• Inventors: WONDKA, Anthony D., BHATNAGAR, Anish, GILBERT, Scott J.
• Granted Patent: US 10,499,819 B2
• Time in Patent Office: Days
• US Class Current: 600/301
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/02055 Simultaneously evaluating both cardiovascular condition and temperature
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/082 Evaluation by breath analysis, e.g. determination of the chemical composition of exhaled breath A61B5/083, A61B5/091 take precedence
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/091 Measuring volume of inspired or expired gases, e.g. to determine lung capacity
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61B 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence
• CPC Class Codes: G16H 10/40 for data related to laboratory analysis, e.g. patient specimen analysis
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

Methods and systems are described to obtain and analyze a gas sample from a desired section of the breath of a person, while accounting for erratic, episodic or otherwise challenging breathing patterns that may otherwise make the capturing of a gas sample from the desired section of breath difficult. These techniques may provide more reliable, accurate and adequate samples of gas such as end-tidal gas, and ultimately an accurate analysis of the sample captured.

Claims

1. An apparatus for analyzing an exhaled breath, comprising:

a sensor that measures a parameter of the exhaled breath;

a first processor that determines if the measured parameter meets a predetermined criteria corresponding to a physiologically representative breath; and

a breath sampling system that stores the exhaled breath when the first processor determines the measured parameter meets the predetermined criteria.

2. The apparatus of claim 1 further comprising a gas analyzer to analyze the stored breath.

3. The apparatus of claim 2, wherein the gas analyzer comprises a second processor that applies a first gas analysis algorithm when the first processor determines the measured parameter meets the predetermined criteria and applies a second gas analysis algorithm when the first processor determines the measured parameter does not meet the predetermined criteria, wherein the second algorithm comprises a correction factor.

4. The apparatus of claim 1 further comprising a physiologic sensor that monitors a physiological parameter of a patient and wherein the breath sampling system does not store the exhaled breath when a third processor determines the physiological parameter does not meet a predetermined physiological criteria.

5. The apparatus of claim 4, wherein the physiologic parameter comprises at least one selected from the group consisting of a blood pressure, a heart rate, chest impedance, a weight, a height, an age, a race, a sex, a diagnosis, a respiratory rate, a tidal volume, a minute volume, an inspiratory:

expiratory ratio, a blood gas, a cardiac output, an end tidal CO₂ concentration, a pulmonary perfusion, a base excess, an O₂ sat, and a ventilation;

perfusion ratio.

6. The apparatus of claim 1, wherein the predetermined criteria comprises a minimum duration.

7. The apparatus of claim 1, wherein the predetermined criteria comprises at least one selected from the group consisting of:

a peak amplitude value, a baseline value, a time duration above the peak amplitude value, a time duration below the baseline value, and a percent comparison of a current breath to a trending algorithm.

8. The apparatus of claim 1, wherein the predetermined criteria comprises an amplitude value and a baseline value representing a complete tidal volume breath

9. The apparatus of claim 1, wherein the predetermined criteria comprises a breath rate of less than or equal to 60 breaths per minute.

10. The apparatus of claim 1, wherein the predetermined criteria is based on at least one selected from the group consisting of an expiratory time, a portion of an expiratory time, an airway pressure, a CO₂ value over time, an O₂ value over time, an airway temperature, a breath flow rate, a breath rate, a depth of breath, a duration of breath, an inspiratory time, a pre-end-tidal time, an end-tidal time, a post-expiratory time, an inspiratory pause, a peak inspiratory pressure, a peak expiratory pressure, a characteristic waveform for sneeze, cough, stacked breath or non-full breath, an inspiratory amplitude, an expiratory amplitude, and a historical breath criteria.

11. The apparatus of claim 1, wherein the predetermined criteria is based upon at least one selected from the group consisting of a breath hold, a deep breath, a forced exhaled breath, an inspiratory pause, an expiratory pause, a resting respiration, and a breath pattern repetition.

12. The apparatus of claim 1, wherein the predetermined criteria is based upon a predetermined number of repetitive breaths.

13. The apparatus of claim 12, wherein the number of repetitive breaths is between 1 and 5 breaths.

14. The apparatus of claim 13, wherein the number of repetitive breaths is between 2 and 4 breaths.

15. An apparatus for analyzing breath gas, comprising:

a sensor that measures parameters of a first exhaled breath, a second exhaled breath, and a third exhaled breath;

a first processor that determines if a first measurement of the first exhaled breath meets a first predetermined criteria;

a second processor that determines if a second measurement of the second exhaled breath meets a second predetermined criteria, wherein the second measurement is made when the first measurement is determined to meet the first predetermined criteria;

a third processor that determines if a third measurement of the third exhaled breath meets a third predetermined criteria, wherein the third measurement is made when the second measurement is determined to meet the second predetermined criteria; and

a breath sampling system that stores the third exhaled breath when the third processor determines the third measured parameter meets the third predetermined criteria.

16. The apparatus of claim 15, wherein the third predetermined criteria is based upon a trend associated with a plurality of breaths.

17. An method for analyzing breath gas, comprising:

measuring parameters of a first exhaled breath, a second exhaled breath, and a third exhaled breath;

determining if a first measurement of the first exhaled breath meets a first predetermined criteria;

determining if a second measurement of the second exhaled breath meets a second predetermined criteria, wherein the second measurement is made when the first measurement is determined to meet the first predetermined criteria;

determining if a third measurement of the third exhaled breath meets a third predetermined criteria, wherein the third measurement is made when the second measurement is determined to meet the second predetermined criteria; and

storing the third exhaled breath when the third measurement is determined to meet the third predetermined criteria.

18. The method of claim 17, wherein the third predetermined criteria is based upon a trend associated with a plurality of breaths.