# US 2014/0194767 A1 · Non-invasive ventilation measurement

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2014/0194767 A1
- Document ID: US20140194767A1
- Status: Published application
- Kind: A1
- Application number: 14/237,937
- Filed: 2012-07-25
- Published: 2014-07-10
- Earliest claimed: 2011-08-25
- Assignees: Koninklijke Philips N.V.
- Inventors: Han Zheng; Samir Ahmad; Masahiro Taniguchi
- Web page: https://patentgrep.com/patent/US20140194767A1

## CPC

- A61B 5/087: Measuring breath flow
- A61B 5/03: Measuring fluid pressure within the body other than blood pressure, e.g. cerebral pressure {; Measuring pressure in body tissues or organs (determining bladder or urethral pressure A61B5/205)}
- A61M 16/026: {specially adapted for predicting, e.g. for determining an information representative of a flow limitation during a ventilation cycle by using a root square technique or a regression analysis}
- A61M 16/161: {with means for measuring the humidity}
- G09B 23/288: {for artificial respiration or heart massage}
- A61M 2016/0027: {pressure meter}
- A61M 2016/0033: {electrical}
- A61M 2205/15: Detection of leaks
- A61M 2205/3365: Rotational speed
- A61M 2205/3368: Temperature
- A61M 2205/502: User interfaces, e.g. screens or keyboards
- A61M 2205/52: with memories providing a history of measured variating parameters of apparatus or patient
- A61M 2230/46: Resistance or compliance of the lungs
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}
- G09B: EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS (devices for psychotechnics or for testing reaction times A61B5/16; games, sports, amusements A63; projectors, projector screens G03B)

## Abstract

Determining the lung compliance and lung resistance of a subject undergoing respiratory therapy using non-invasive ventilation requires taking the presence of leaks into account. In particular, variable and unintentional leaks at or near a subject interface appliance may be dynamically determined based on an average resistance of the leak orifice of the subject.

## Claims

### Claim 1

A system configured to measure respiratory parameters during application of non-invasive respiratory therapy of a subject, the system comprising:
one or more processors configured to execute computer program modules, wherein the computer program modules comprise:
a timing module configured to determine transitions in breathing between inhalations and exhalations;
a passive compliance module configured to determine a passive exhalation lung compliance during an exhalation, wherein the determination by the passive compliance module is based on a passive lung model, and wherein the exhalation is demarcated based on the transitions;
a passive resistance module configured to determine a passive exhalation lung resistance during the exhalation, wherein the determination by the passive resistance module is based on the passive lung model;
an active compliance module configured to determine an active lung compliance that reflects an active lung model, wherein the active lung compliance is determined based on the passive exhalation lung compliance and a subject breathing mode;
an active resistance module configured to determine an active lung resistance that reflects the active lung model, wherein the active lung resistance is determined based on the passive exhalation lung resistance and the subject breathing mode; and
a flow module configured to determine an instantaneous estimated subject flow, wherein the flow module takes a presence of both (i) instantaneous known respiratory circuit leaks and (ii) instantaneous unknown respiratory circuit leaks into account to determine the instantaneous estimated subject flow.

### Claim 2 (depends on 1)

The system of claim 1, wherein the passive compliance module is further configured to determine a passive inhalation lung compliance during an inhalation, wherein the inhalation is demarcated based on the transitions, wherein the passive resistance module is further configured to determine a passive inhalation lung resistance during the inhalation, wherein the determination by the active compliance module is further based on the passive inhalation lung compliance, and wherein the determination by the active resistance module is further based on the passive inhalation lung resistance.

### Claim 3 (depends on 1)

The system of claim 1,
wherein the flow module is further configured to determine a breath-by-breath subject flow based on a respiratory circuit flow, wherein the passive lung model is based on the determined breath-by-breath subject flow.

### Claim 4 (depends on 3)

The system of claim 3, wherein application of the non-invasive respiratory therapy includes a systemic leak, wherein the systemic leak includes a known circuit leak and an unknown leak at or near a leak orifice of the subject, and wherein determination by the flow module of the breath-by-breath subject flow is further based on the systemic leak.

### Claim 5 (depends on 4)

The system of claim 4, wherein the unknown leak at or near the leak orifice of the subject is based on an average resistance of the leak orifice.

### Claim 6 (depends on 5)

The system of claim 5, wherein the average resistance of the leak orifice is determined based on the transitions in breathing between inhalations and exhalations.

### Claim 7 (depends on 1)

The system of claim 1, wherein the subject breathing mode is a spontaneous breathing mode or a non-spontaneous breathing mode.

### Claim 8

A method for measuring respiratory parameters during non-invasive respiratory therapy of a subject, the method comprising:
determining transitions in breathing between inhalations and exhalations;
determining a passive exhalation lung compliance, during an exhalation, based on a passive lung model, wherein the exhalation is demarcated based on the transitions;
determining a passive exhalation lung resistance, during the exhalation, based on the passive lung model;
obtaining a subject breathing mode;
determining an active lung compliance that reflects an active lung model, wherein the determination is based on the passive exhalation lung compliance and the subject breathing mode;
determining an active lung resistance that reflects the active lung model, wherein the determination is based on the passive exhalation lung resistance and the subject breathing mode; and
determining an instantaneous estimated subject flow, wherein determining the instantaneous estimated subject flow takes a presence of both (i) instantaneous known respiratory circuit leaks and (ii) instantaneous unknown respiratory circuit leaks into account to determine the instantaneous estimated subject flow.

### Claim 9 (depends on 8)

The method of claim 8, further comprising:
determining a passive inhalation lung compliance, during an inhalation, wherein the inhalation is demarcated based on the transitions; and
determining a passive inhalation lung resistance, during the inhalation, wherein determining the active lung compliance is further based on the passive inhalation lung compliance, and wherein determining the active lung resistance is further based on the passive inhalation lung resistance.

### Claim 10 (depends on 8)

The method of claim 8, further comprising:
obtaining a respiratory circuit flow of the non-invasive respiratory therapy of the subject; and
determining a breath-by-breath subject flow based on the respiratory circuit flow,
wherein the passive lung model is based on the determined breath-by-breath subject flow.

### Claim 11 (depends on 10)

The method of claim 10, wherein application of the non-invasive respiratory therapy includes a systemic leak, wherein the systemic leak includes a known circuit leak and an unknown leak at or near a leak orifice of the subject, and wherein determining the breath-by-breath subject flow is further based on the systemic leak.

### Claim 12 (depends on 11)

The method of claim 11, further comprising:
determining the unknown leak at or near the leak orifice of the subject based on an average resistance of the leak orifice.

### Claim 13 (depends on 12)

The method of claim 12, further comprising:
determining the average resistance of the leak orifice based on the transitions in breathing between inhalations and exhalations.

### Claim 14 (depends on 8)

The method of claim 8, wherein the subject breathing mode is a spontaneous breathing mode or a non-spontaneous breathing mode.

### Claim 15

A system configured for measuring respiratory parameters during application of non-invasive respiratory therapy of a subject, the system comprising:
means for determining transitions in breathing between inhalations and exhalations;
means for determining a passive exhalation lung compliance, during an exhalation, based on a passive lung model, wherein the exhalation is demarcated based on the transitions;
means for determining a passive exhalation lung resistance, during the exhalation, based on the passive lung model;
means for obtaining a subject breathing mode;
means for determining an active lung compliance, reflecting an active lung model, based on the passive exhalation lung compliance and the subject breathing mode;
means for determining an active lung resistance, reflecting the active lung model, based on the passive exhalation lung resistance and the subject breathing mode; and
means for determining an instantaneous estimated subject flow, wherein determining the instantaneous estimated subject flow takes a presence of both (i) instantaneous known respiratory circuit leaks and (ii) instantaneous unknown respiratory circuit leaks into account to determine the instantaneous estimated subject flow.

### Claim 16 (depends on 15)

The system of claim 15, further comprising:
means for determining a passive inhalation lung compliance, during an inhalation, wherein the inhalation is demarcated based on the transitions; and
means for determining a passive inhalation lung resistance, during the inhalation,
wherein operation of the means for determining the active lung compliance is further based on the passive inhalation lung compliance, and wherein operation of the means for determining the active lung resistance is further based on the passive inhalation lung resistance.

### Claim 17 (depends on 15)

The system of claim 15, further comprising:
means for obtaining a respiratory circuit flow of the non-invasive respiratory therapy of the subject; and
means for determining a breath-by-breath subject flow based on the respiratory circuit flow,
wherein the passive lung model is based on the determined breath-by-breath subject flow.

### Claim 18 (depends on 17)

The system of claim 17, wherein application of the non-invasive respiratory therapy includes a systemic leak, wherein the systemic leak includes a known circuit leak and an unknown leak at or near a leak orifice of the subject, and wherein operation of the means for determining the breath-by-breath subject flow is further based on the systemic leak.

### Claim 19 (depends on 18)

The system of claim 18, further comprising:
means for determining the unknown leak at or near the leak orifice of the subject based on an average resistance of the leak orifice.

### Claim 20 (depends on 19)

The system of claim 19, further comprising:
means for determining the average resistance of the leak orifice based on the transitions in breathing between inhalations and exhalations.

### Claim 21

(canceled)