# US 8,465,434 B2 · Method and system for detection of respiratory variation in plethysmographic oximetry

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- Number: US 8,465,434 B2
- Document ID: US8465434B2
- Status: Granted
- Kind: B2
- Application number: 13/404,265
- Filed: 2012-02-24
- Published: 2012-07-05
- Granted: 2013-06-18
- Earliest claimed: 2007-12-06
- Assignees: Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center
- Applicants: Gregory R. Mason; John M. Criley
- Inventors: Gregory R. Mason; John M. Criley
- Web page: https://patentgrep.com/patent/US8465434B2

## CPC

- A61B 5/0205: Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
- A61B 5/349: Detecting specific parameters of the electrocardiograph cycle
- A61B 5/02416: {using photoplethysmograph signals, e.g. generated by infrared radiation (A61B5/14552 takes precedence)}
- A61B 5/0816: {Measuring devices for examining respiratory frequency (measuring frequency of electric signals G01R23/00)}
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)

## Abstract

A method and system for detection of respiratory variation in pulse oximetry are provided. In one embodiment, the method includes detecting a pattern consistent with a respiratory cycle of a waveform representing cardiac oscillations and identifying an abnormality based on the pattern. A system is further provided including a database and a module. The database to store data representing a physiological condition of a patient over a period of time, wherein the data comprises data corresponding to respiratory activity and data corresponding to cardiac oscillations, wherein the data corresponding to respiratory activity comprises a first waveform and the data corresponding to the cardiac oscillations comprises a second waveform; and a module for detecting a pattern of the second waveform consistent with a cycle of a first waveform and detecting an abnormality in the pattern.

## Claims

### Claim 1

A system comprising:
a database to store data representing a physiological condition of a patient over a period of time, wherein the data comprises data corresponding to respiratory activity and data corresponding to cardiac oscillations, wherein the data corresponding to respiratory activity comprises a first waveform and the data corresponding to the cardiac oscillations comprises a second waveform; and
a module for detecting a pattern of the second waveform consistent with a cycle of the first waveform and detecting an abnormality indicative of pulsus paradoxus in the pattern, and
wherein detecting the abnormality comprises determining a value from the pattern based on an average offset of wave bases of the second waveform from a baseline and an average amplitude of wave peaks of the second waveform from a best-fit line to the wave bases.

### Claim 2 (depends on 1)

The system of claim 1, wherein the second waveform comprises a plethysmographic waveform and the first waveform comprises a respiratory waveform.

### Claim 3 (depends on 1)

The system of claim 1, further comprising:
an interface for displaying the first waveform and the second waveform.

### Claim 4 (depends on 1)

The system of claim 1, wherein each of the first waveform and the second waveform data is generated by a pulse oximeter.

### Claim 5 (depends on 1)

The system of claim 1, wherein the first waveform data and the second waveform data is generated from a plurality of monitoring devices coupled to a patient.

### Claim 6 (depends on 1)

The system of claim 1, wherein the second first waveform data comprises an electrocardiogram (ECG) waveform.

### Claim 7 (depends on 1)

The system of claim 1, wherein the waveform representing respiratory activity is obtained from impedance plethysmography using an electrocardiogram (ECG) coupled to a patient.

### Claim 8 (depends on 1)

The system of claim 1, wherein when the abnormality is detected an alarm is triggered to alert a health care provider of the abnormality.