NEONATAL CARBON DIOXIDE MEASUREMENT SYSTEM

• US 20150065900A1
• Filed: 08/29/2014
• Published: 03/05/2015
• Est. Priority Date: 08/30/2013
• Status: Active Grant

• Current Assignee: Capnia, Inc.
• Original Assignee: Capnia, Inc.
• Inventors: WONDKA, Anthony D., BHATNAGAR, Anish, DE LA SERNA, Pedro E.
• Granted Patent: US 11,191,449 B2
• Time in Patent Office: Days
• US Class Current: 600/531
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/0836 Measuring rate of CO2 production
• CPC Class Codes: A61B 5/097 Devices for facilitating collection of breath or for directing breath into or through measuring devices
• CPC Class Codes: G01N 33/497 of gaseous biological material, e.g. breath

Abstract

A breath parameter measuring device is described which takes into account breathing patterns which historically have been incompatible with accurate measurements. In particular, during fast breathing patterns, the sensor performing the measurement may not be able to respond quickly enough to provide the true reading. The disclosure may be useful for example in the case of neonatal breath carbon dioxide measurements.

Claims

1. A method of measuring a breath analyte comprising:

monitoring a series of breaths with a first sensor;

determining a plurality of breath segments of the series of breaths to capture, wherein each of the plurality of breath segments comprises a duration in the first sensor shorter than an analyte response time of the first sensor;

collecting the plurality of breath segments together; and

measuring an analyte concentration of the collection of breath segments using a second sensor, wherein the collection of breath segments comprises a duration longer than a response time of the second sensor.

2. The method of claim 1, wherein the first sensor and the second sensor are the same sensor.

3. The method of claim 1, wherein the first sensor and the second sensor are both capable of measuring the analyte.

4. The method of claim 1, wherein monitoring the series of breaths comprises monitoring each breath'"'"'s breath rate.

5. The method of claim 1, wherein monitoring the series of breath comprises monitoring each breath'"'"'s capnometry signal.

6. The method of claim 1, wherein determining a plurality of breath segments of the series of breaths to capture comprises identifying breaths with a normal end-tidal profile.

7. The method of claim 1, wherein determining a plurality of breath segments of the series of breaths to capture comprises excluding one or more of a non-steady state breath, an episodic breath, and an erratic breath.

8. The method of claim 1, wherein the analyte is CO₂.

9. The method of claim 1, wherein the first sensor is an infrared CO₂ sensor.

10. The method of claim 1, wherein each of the plurality of breath segments comprises substantially all of the last 150 msec of the respective breath.

11. The method of claim 1, wherein collecting the plurality of breath segments together comprises drawing the plurality of breath segments into a collection chamber using a pump, and wherein

measuring an analyte concentration of the collection of breath segments using a second sensor comprises reversing the pump to send the collection of breath segments to the second sensor.

12. The method of claim 1, wherein collecting the plurality of breath segments together comprises drawing the plurality of breath segments into a collection chamber using a pump, and wherein

measuring an analyte concentration of the collection of breath segments using a second sensor comprises not reversing the pump to send the collection of breath segments to the second sensor.

13. A system for measuring a breath analyte comprising:

a first sensor that generates data from a series of breaths;

a processor that receives the data and determines a plurality of breath segments of the series of breaths to capture based on the data, wherein each of the plurality of breath segments comprises a duration in the first sensor shorter than an analyte response time of the first sensor;

a chamber that collects the plurality of breath segments together; and

a second sensor that measures an analyte concentration of the collection of breath segments, wherein the collection of breath segments comprises a duration longer than a response time of the first sensor.

14. The apparatus of claim 13, wherein the first sensor and the second sensor are the same sensor.

15. The apparatus of claim 13, wherein the first sensor and the second sensor are both capable of measuring the analyte.

16. The apparatus of claim 13, wherein the first sensor generates data on a breath rate of each breath of the series of breaths.

17. The apparatus of claim 13, wherein the first sensor generates data on a capnometry signal of each breath of the series of breaths.

18. The apparatus of claim 13, wherein the processor determines the plurality of breath segments of the series of breaths to capture by identifying breaths with a normal end-tidal profile.

19. The apparatus of claim 13, wherein the processor determines the plurality of breath segments of the series of breaths to capture by excluding one or more of a non-steady state breath, an episodic breath, and an erratic breath.

20. The apparatus of claim 13, wherein the analyte is CO₂.

21. The apparatus of claim 13, wherein the first sensor is an infrared CO₂ sensor.

22. The apparatus of claim 13, wherein each of the plurality of breath segments comprises substantially all of the last 150 msec of the respective breath.

23. The apparatus of claim 13, further comprising a pump to draw the plurality of breath segments into the chamber, and wherein the pump routes the collection of breath segments to the second sensor.

24. The apparatus of claim 23, wherein the pump is not reversed to route the collection of breath segments to the second sensor.