System And Method For Monitoring Breathing

• US 20100268105A1
• Filed: 04/14/2010
• Published: 10/21/2010
• Est. Priority Date: 04/17/2009
• Status: Active Grant

• Current Assignee: Linshom Management, LLC
• Original Assignee: Linshom LP
• Inventors: Moser, John, Feldman, Ronen, Feldman, Uri, Lerman, Jerrold, Feldman, Doron
• Granted Patent: US 8,579,829 B2
• Time in Patent Office: Days
• US Class Current: 600/529
• CPC Class Codes: A61B 2560/0242 adapted to measure environmental factors, e.g. temperature, pollution
• CPC Class Codes: A61B 5/0803 Recording apparatus specially adapted therefor
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/0878 using temperature sensing means
• CPC Class Codes: A61B 5/091 Measuring volume of inspired or expired gases, e.g. to determine lung capacity
• CPC Class Codes: A61B 5/4818 Sleep apnoea

Abstract

A system for monitoring the breathing status of a patient comprises a first temperature sensor and a second temperature sensor. The first temperature sensor is arranged to measure the temperature of the breathing gas of a patient. The second temperature sensor is arranged to measure an ambient temperature of the patient'"'"'s surroundings. A controller is included, wherein the controller is programmed to determine a plurality of breathing-gas temperatures over time by way of a first signal received from the first temperature sensor and at least one ambient temperature using a second signal received from the second temperature sensor. The controller is programmed to analyze the plurality of breathing-gas temperatures and the at least one ambient temperature to determine a breathing status of the patient. The present invention may be embodied as a method for monitoring the breathing status of a patient.

Claims

1. A breathing monitoring system, comprising:

a) a first temperature sensor arranged to measure a patient'"'"'s breathing-gas temperature;

b) a second temperature sensor arranged to measure an ambient temperature; and

c) a controller programmed to;

i) determine a plurality of breathing-gas temperatures over time using a first signal received from the first temperature sensor;

ii) determine at least one ambient temperature using a second signal received from the second temperature sensor; and

iii) analyze the plurality of breathing-gas temperatures and the at least one ambient temperature to determine a breathing status of the patient.

2. The system of claim 1, wherein the controller is programmed to analyze the plurality of breathing-gas temperatures by determining a maximum breathing-gas temperature and a minimum breathing-gas temperature during a time interval, the time interval corresponding to a period of the patient'"'"'s inhalation/exhalation cycle.

3. The system of claim 2, wherein the controller is programmed to analyze the plurality of breathing-gas temperatures by calculating a mathematical difference (“

Δ

Tm”

) between the maximum breathing-gas temperature and the minimum breathing-gas temperature.

4. The system of claim 3, wherein the controller is programmed to analyze the plurality of breathing-gas temperatures by comparing the calculated Δ

Tm with a threshold Δ

Tm, wherein if the calculated Δ

Tm is less than the threshold Δ

Tm, the breathing status of the patient is unsatisfactory.

5. The system of claim 4, further comprising an alarm in communication with the controller, wherein the controller is programmed to activate the alarm if the breathing status of the patient is unsatisfactory.

6. The system of claim 4, wherein the controller is programmed to:

(a) calculate a bias temperature (“

Tbias”

), Tbias being the mathematical difference of an average breathing-gas temperature and a time-based average ambient temperature; and

(b) determine the threshold Δ

Tm from the ambient temperature and Tbias.

7. The system of claim 6, wherein the controller comprises a memory device having a pre-defined look-up table, and wherein the controller is programmed to determine the threshold Δ

Tm from the ambient temperature and Tbias by using the ambient temperature and Tbias to look up a threshold Δ

Tm in the look-up table.

8. The system of claim 6, wherein the controller comprises a field-programmable gate array (“

FPGA”

), and the FPGA is programmed to determine the threshold Δ

Tm from the ambient temperature and Tbias.

9. The system of claim 8, wherein the FPGA is programmed to use a decision-tree to determine the threshold Δ

Tm based on the values of the ambient temperature and Tbias.

10. The system of claim 6, wherein the controller comprises a memory device having a pre-defined multi-dimensional look-up table, the look-up table relating a plurality of pre-defined program steps to particular combinations of ambient temperature, Δ

Tm, Tbias values, and the controller is programmed to determine a program step based on the measured ambient temperature and calculated Δ

Tm and Tbias.

11. The system of claim 10, wherein the controller is programmed to execute the determined program step.

12. The system of claim 6, wherein the controller is programmed to use a decision-tree to determine the threshold Δ

Tm based on the values of the ambient temperature and Tbias.

13. A method for monitoring the breathing of a patient, comprising the steps of:

a) using a first temperature sensor to measure the patient'"'"'s breathing-gas temperature;

b) using a second temperature sensor to measure an ambient temperature; and

c) providing a controller programmed to;

i) determine a plurality of breathing-gas temperatures over time using a first signal received from the first temperature sensor;

ii) determine at least one ambient temperature using a second signal received from the second temperature sensor; and

iii) analyze the plurality of breathing-gas temperatures and the at least one ambient temperature to determine a breathing status of the patient; and

d) using the controller to determine a plurality of breathing-gas temperatures, at least one ambient temperature and analyze the breathing-gas temperatures and the at least one ambient temperature;

(e) using the controller to determine a breathing status of the patient;

(f) communicating the breathing status of the patient to a human being.

14. The method of claim 13, wherein communicating the breathing status of the patient comprises using the controller to activate an alarm if the breathing status of the patient is determined to be unsatisfactory.

15. The method of claim 13, wherein the controller is programmed to analyze the plurality of breathing-gas temperatures by determining a maximum breathing-gas temperature and a minimum breathing-gas temperature during a time interval, the time interval corresponding to a period of the patient'"'"'s inhalation/exhalation cycle.

16. The method of claim 13, wherein the controller is programmed to analyze the plurality of breathing-gas temperatures by calculating a mathematical difference (“

Δ

Tm”

) between the maximum breathing-gas temperature and the minimum breathing-gas temperature.

17. The method of claim 16, wherein the controller is programmed to analyze the plurality of breathing-gas temperatures by comparing the calculated Δ

Tm with a threshold Δ

Tm, wherein if the calculated Δ

Tm is less than the threshold Δ

Tm, the breathing status of the patient is unsatisfactory.