Method for non-cooperative lung function diagnosis using ultrasound

• US 20070191726A1
• Filed: 09/02/2005
• Published: 08/16/2007
• Est. Priority Date: 09/03/2004
• Status: Active Grant

• Current Assignee: Medizintechnik AG
• Original Assignee: Medizintechnik AG
• Inventors: Buess, Christian, Harnoncourt, Karl
• Granted Patent: US 7,635,339 B2
• Time in Patent Office: Days
• US Class Current: 600/532
• CPC Class Codes: A61B 5/0836 Measuring rate of CO2 production
• CPC Class Codes: A61B 5/087 Measuring breath flow

Abstract

A method and device are provided for measuring state of lung function of a patient using ultrasonic flow and molar mass measurement. Flow and molar mass signals are recorded during tidal breathing without requiring patient cooperation. Statistical analysis of the recorded data in combination with anthropometirc data and/or data form a questionnaire can be used to diagnose various pulmonary ailments or diseases.

Claims

1. Device for non-cooperative lung function diagnosis, comprising

an ultrasonic gas flow and molar mass sensor based upon a transit-time or time-of-flight method,

an exchangeable or fixed flow tube having a mouthpiece, and

software used for non-cooperative tidal breathing analysis of a patient by measuring flow, volume and molar mass, using a statistical method for analysis of said measured signals and subsequently deriving from results of the analysis a lung function status index for diagnostic or monitoring purposes.

2. Device according to claim 1, structured and arranged to perform the analysis based on a single deep exhalation or a combination of quiet breathing and a single deep exhalation, by the patient.

3. Device according to claim 2, wherein the derived lung function status index is structured and arranged to be used for the diagnosis or prediction of COPD (chronic obstructive pulmonary disease) or asthma.

4. Device according to claim 3, structured and arranged to perform the statistical analysis using at least one of

(i) a molar mass over volume graph,

(ii) molar mass over time graph,

(iii) parameters directly derived from flow,

(iv) anthropometric data from the patient such as gender, ethnicity, height, age, weight etc., and

(v) data from a questionnaire answered by the patient.

5. Device according to claim 4, structured and arranged to use native molar mass, assuming a fixed temperature for the molar mass computation, or normal molar mass by using a temperature model, one or several temperature measurements or a combination of both for computing temperature along the sound transmission path.

6. Device according to claim 5, structured and arranged to base the statistical analysis on a single or several breaths of tidal breathing where during several breaths, data of the several breaths is overlaid to construct an averaged curve.

7. Device according to claim 6, structured and arranged to be used for trending of lung function status in a patient.

8. Device according to claim 7, wherein the statistical analysis uses “

fuzzy class”

prediction.

9. Device according to claim 8, structured and arranged to be used for screening a population for lung function abnormalities.

10. Method for non-cooperative lung function diagnosis comprising the steps of using a device including of an ultrasonic gas flow and molar mass sensor based on a transit-time or time-of-flight method, an exchangeable or fixed flow tube with a mouthpiece, and appropriate software used for non-cooperative tidal breathing analysis of a patient by the steps of

measuring flow, volume and molar mass,

using statistical method for analysis of said measured signals, and

subsequently deriving from results of the analysis a lung function status index for diagnostic or monitoring purposes.

11. Method according to claim 10, comprising the step of basing on a single deep exhalation or a combination of quiet breathing and a single deep exhalation.

12. Method according to claim 11, comprising the step of using the lung function status index for the diagnosis or prediction of COPD (chronic obstructive pulmonary disease) or asthma.

13. Method according to claim 12, comprising the step of performing the statistical analysis using at least one of

(i) a molar mass over volume graph,

(ii) a molar mass over time graph,

(iii) parameters directly derived from flow,

(iv) anthropometric data from the patient such as gender, ethnicity, height, age, weight etc., and

(v) data from a questionnaire answered by the patient.

14. Method according to claim 13, comprising the step of using native molar mass, where a fixed temperature is assumed for the molar mass computation, or normal molar mass by the step of using a temperature model, one or several temperature measurements or a combination of both for computing temperature along the sound transmission path.

15. Method according to claim 14, comprising the step of basing the statistical analysis on a single or several breaths of tidal breathing, where in the case of several breaths data of said several breaths is overlaid to construct an averaged curve.

16. Method according to claim 15, comprising the step of trending lung function status in a patient.

17. Method according to claim 16, wherein the statistical analysis uses “

fuzzy class”

prediction.

18. Method according to claim 17, comprising the step of screening a population for lung function abnormalities.