Methods and systems for determining dynamic hyperinflation

• US 7,878,979 B2
• Filed: 05/19/2006
• Issued: 02/01/2011
• Est. Priority Date: 05/20/2005
• Status: Active Grant

• Current Assignee: Adidas AG
• Original Assignee: Adidas AG
• Inventors: Derchak, P. Alexander
• Primary Examiner(s): Mallari; Patricia C
• Application Number:
  US11/437,335
• Publication Number:
  US 20070049843A1
• Time in Patent Office: 1,719 Days
• Field of Search: 600/529, 600/534
• US Class Current: 600/529
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• 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 5/0806 by whole-body plethysmography measuring blood flow using plethysmography A61B5/0295; impedance plethysmography A61B5/053; measuring volume of the body or parts thereof A61B5/1073
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/091 Measuring volume of inspired or expired gases, e.g. to determine lung capacity
• CPC Class Codes: A61B 5/1135 by monitoring thoracic expansion
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/411 Detecting or monitoring allergy or intolerance reactions to an allergenic agent or substance
• CPC Class Codes: A61B 5/6805 Vests
• CPC Class Codes: A61B 5/6831 Straps, bands or harnesses
• CPC Class Codes: G16H 40/67 for remote operation
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass

Abstract

This invention provides methods and systems for non-invasively determining the presence (and amount) or absence of dynamic hyperinflation in a subject. The invention is based on a novel combination of respiratory parameters that can be measured in a way that is non-invasive and unobtrusive to the subject. Dynamic hyperinflation is often a significant factor in the quality of life of patients suffering from a variety of obstructive pulmonary diseases, and this invention permits simple, routine tracking and management of dynamic hyperinflation in affected patients.

Claims

1. A computer-implemented method for assessing dynamic hyperinflation (DH) in a monitored subject, comprising:

receiving respiratory data monitored with a physiological monitoring system during a current period of monitoring the subject, said monitoring system having at least one sensor, said respiratory, data including respiratory volumes during rib cage(RC) expansion and contraction;

determining from said received data at one or more times during said current monitoring period a first parameter (M % RC) with processor means, said first parameter comprising median % rib cage, said first parameter (M % RC) reflecting relative contributions of expansions and contractions of the rib cage (RC) to tidal volumes (V_T) of the subject;

determining from said received data at one or more times during said current monitoring period a second parameter (MqdEELV) with said processor means, said second parameter (MqdEELV) comprising median cumulative changes in end-expiratory lung volume; and

assessing DH in the subject during said current monitoring period in dependence on said determined MqdEELV and M % RC parameters.

2. The computer-implemented method of claim 1, wherein said current monitoring period comprises a plurality of sub-periods, and wherein said M % RC parameter and said MqdEELV parameter are determined for each of said plurality of sub-periods only from received respiratory data from that sub-period.

3. The computer-implemented method of claim 1, wherein DH is present during said current monitoring period if M % RC parameter values increase and if MqdEELV parameter values decrease during said current monitoring period.

4. The computer-implemented method of claim 1, wherein DH is present during said current monitoring period in comparison with a previous monitoring period if M % RC parameter values during said current monitoring period are greater than during said, previous monitoring period and if said MqdEELV parameter values during said current monitoring period are less than during said previous monitoring period.

5. The computer-implemented method of claim 4, wherein said previous monitoring period comprises a baseline period during which DH is known to be absent.

6. The computer-implemented method of claim 1, wherein said determination of said M % RC parameter comprises dividing said respiratory volumes during rib cage (RC) expansion and contraction by tidal volume (V_T).

7. The computer-implemented method of claim 6, wherein said received data comprises rib cage (RC) sizes at one or more selected positions on the subject, and wherein said respiratory volumes during rib cage (RC) expansion and contraction are determined in dependence on one or more rib cage (RC) sizes.

8. The computer-implemented method of claim 1, wherein determination of said MqdEELV parameter comprises

determining a breath-by-breath change in expiratory lung volume (EELV) for a first period of time,

determining a cumulative change in said EELV in dependence on plurality of consecutive breath-by-breath changes in said EELV, and

determining said MqdEELV parameter in dependence on the absolute values of said plurality of cumulative changes in said EELV.

9. The computer-implemented method of claim 8, wherein said determination of a breath-by-breath change in EELV comprises subtracting expiratory volume of a breath from inspiratory volume of said breath.

10. The computer-implemented method of claim 1, wherein said received data comprises anatomical sizes at one or more positions on the subject'"'"'s torso, said torso positions including one or more positions on the rib cage (RC) and one or more positions on the abdomen (AB), and wherein the method further comprises

determining moment-by-moment lung volume parameters by linearly combining said rib cage (RC) and abdomen (AB) sizes, and

determining tidal volume, (V_T) in dependence on a difference between a first lung volume parameter at the end of inspiration and a second lung volume parameter at end of an immediately following expiration.

11. The method of claim 1, wherein the subject comprises a mammal.

12. The method of claim 1, wherein the subject performs normal daily activities during the monitoring period.

21. The computer-readable medium comprising encoded instructions for causing a processor to perform the method of claim 1.

13. A computer for assessing dynamic hyperinflation (DH) in a monitored subject, comprising:

a processor, and

a computer-readable memory operatively coupled to said processor and configured with computer instructions that cause said processor to perform the steps of receiving comparative respiratory data monitored during a current period of monitoring, determining from said received data at one or more times during said monitoring period a first parameter (M % RC), said first parameter (M % RC) comprising median % rib cage, determining from said received data at one or more times during said monitoring period a second parameter (MqdEELV), said second parameter (MqdEELV) comprising median cumulative changes in end-expiratory lung volume, and assessing DH in the subject during said monitoring period in dependence on said determined MqdEELV and M % RC parameters.

14. The computer of claim 13, wherein said processor and memory are sized and configured, whereby said processor and memory can be easily carried by the subject.

15. A portable monitoring system for assessing dynamic hyperinflation (DH) in a monitored subject, comprising:

a wearable item comprising one or more sensors that provide data comprising sizes at one or more selected positions on the subject'"'"'s torso, said selected positions including one or more positions on the rib cage (RC) and one or more positions on the abdomen (AB), said selected positions being selected so that said torso sizes change with respiration;

a portable data unit operably linked to said sensors, said portable data unit comprising a processing device and a computer memory operably linked to said processing device and configured with computer instructions that cause said processor to perform the steps of

receiving sensor data monitored during a current period of monitoring,

determining tidal volume (V_T) in dependence on a difference between a first moment-by-moment lung volume parameter at end of inspiration and a second lung volume parameter at end of an immediately following expiration,

determining from said received data at one or more times during said monitoring period a first parameter (M % RC), said first parameter (M % RC) comprising median % rib cage,

wherein determination of said M % RC parameter comprises dividing respiratory volumes due to rib cage (RC) expansion and contraction by tidal volume (V_T),

determining from said received data at one or more times during said monitoring period a second parameter (MqdEELV), said second parameter (MqdEELV) comprising median cumulative changes in end-expiratory lung volume, wherein determination of said MqdEELV parameter comprises determining a breath-by-breath change in expiratory lung volume (EELV), determining a cumulative change in said EELV in dependence on a plurality of consecutive breath-by-breath changes in said EELV, and determining said MqdEELV parameter in dependence on absolute values of said plurality of cumulative changes in said EELV, and

assessing DH in the subject during said monitoring period in dependence on said determined MqdEELV and M % RC parameters.

16. The portable monitoring system of claim 15, wherein said wearable item comprises a garment and/or a shirt and/or a band.

17. The portable monitoring system of claim 15, wherein said portable data unit is housed so as to be carried on said wearable item of clothing worn by the subject.

18. The portable monitoring system of claim 15, wherein said sensors comprise one or more inductive plethysmographic sensors or one or more posture and/or activity sensors.

19. The portable system of claim 15, wherein said portable data unit stores data on a removable computer-readable memory.

20. The portable monitoring system of claim 15, wherein said portable data unit wirelessly transmits data to a remote computer.