Method and system to measure ECG and respiration

• US 8,396,537 B2
• Filed: 04/20/2009
• Issued: 03/12/2013
• Est. Priority Date: 04/20/2009
• Status: Active Grant

• Current Assignee: Shenzhen Mindray Bio-Medical Electronics Co., Ltd. (Excelsior Union Ltd.)
• Original Assignee: Mindray DS USA Incorporated (Excelsior Union Ltd.)
• Inventors: Balji, Jack, Rajagopalan, Cadathur
• Primary Examiner(s): Koharski, Christopher D
• Assistant Examiner(s): MAHMOOD, NADIA AHMAD
• Application Number:
  US12/426,834
• Publication Number:
  US 20100268093A1
• Time in Patent Office: 1,422 Days
• Field of Search: 600/509
• US Class Current: 600/509
• CPC Class Codes: A61B 2562/06 Arrangements of multiple sensors of different types
• CPC Class Codes: A61B 2562/168 Fluid filled sensor housings
• 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 5/0809 by impedance pneumography
• CPC Class Codes: A61B 5/1126 using a particular sensing technique
• CPC Class Codes: A61B 5/113 occurring during breathing
• CPC Class Codes: A61B 5/25 Bioelectric electrodes therefor
• CPC Class Codes: A61B 5/259 using conductive adhesive means, e.g. gels
• CPC Class Codes: A61B 5/274 using snap or button fasteners
• CPC Class Codes: A61B 5/279 specially adapted for particular uses
• CPC Class Codes: A61B 5/28 for electrocardiography [ECG]
• CPC Class Codes: A61B 5/339 Displays specially adapted therefor
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 5/6823 Trunk, e.g., chest, back, abdomen, hip
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B

Abstract

A method for monitoring the respiration rate of a patient includes attaching a plurality of electrocardiogram (ECG) electrodes and a pressure sensor to a patient, producing a first respiration signal based on variations detected in signals provided by the ECG electrodes attached to the patient, and producing a second respiration signal based on pressure variations detected in the pressure sensor secured to the patient. The method also includes selecting at least one of the first respiration signal and the second respiration signal based on respective signal qualities and producing a respiration rate from the selected signal. The method also includes providing indicia of the respiration rate. The method may also include displaying ECG signals with the indicia of the respiration rate.

Claims

1. A patient monitoring system comprising:

a plurality of electrocardiogram (ECG) lead channels configured to communicate with a plurality of ECG electrodes configured to attach to a patient;

an ECG respiration component to produce a first respiration signal based on variations detected in the ECG lead channels;

a pressure measurement channel to communicate with a pressure sensor attached to the patient;

a pressure respiration component configured to detect variations in the pressure measurement channel and to produce a second respiration signal based on pressure variations detected in the pressure measurement channel;

a first respiration signal quality check component to determine a first signal quality corresponding to the first respiration signal; and

a second respiration signal quality check component to determine a second signal quality corresponding to the second respiration signal;

respiration decision logic configured to compare the first signal quality to the second signal quality and to produce a respiration rate from at least one of the first respiration signal and the second respiration signal based on the comparison of the first signal quality and the second signal quality; and

a display device to provide indicia of the respiration rate.

2. The system of claim 1, wherein the variations detected in the ECG lead channels comprise variations in thoracic impedance during patient respiration.

3. The system of claim 2, wherein the ECG respiration component is configured to:

produce an impedance signal between two or more of the ECG electrodes; and

produce the first respiration signal based on variations in the impedance signal.

4. The system of claim 1, wherein the ECG lead channels are configured to receive ECG signals related to electrical waves that cause the patient'"'"'s heart muscle to pump, and wherein the variations detected in the ECG lead channels comprise variations in the ECG signals corresponding to patient respiration.

5. The system of claim 1, further comprising an ECG electrode to detect ECG signals related to electrical waves that cause the patient'"'"'s heart muscle to pump, the ECG electrode configured and sized to temporarily secure the pressure sensor to the patient.

6. The system of claim 1, further comprising an integrated apparatus for measuring electrical signals and physical movements in the patient, the integrated apparatus comprising:

a body comprising a top surface and a bottom surface;

an electrically conductive adhesive covering at least a portion of the bottom surface to temporarily secure the integrated apparatus to the patient'"'"'s skin;

an electrically conductive lead attachment passing from the top surface to the bottom surface of the body to provide electrical communication between the patient'"'"'s skin and one of the ECG lead channels;

a pressure capsule secured below the top surface of the body, the pressure capsule responsive to changes in pressure applied thereto; and

a pressure communication tube connected to the pressure capsule to communicate pressure variations within the pressure capsule to the pressure measurement channel.

7. The system of claim 6, wherein the integrated apparatus is disposable.

8. The system of claim 1, further comprising a respiration alarm to:

compare the respiration rate produced by the respiration decision logic to a respiration rate threshold condition; and

provide indicia of an alarm based on the comparison.

9. The system of claim 1, wherein the display device displays a numerical value of the respiration rate.

10. The system of claim 1, wherein the display device displays a waveform representing the sequence of times corresponding to the respiration rate.

11. A method for monitoring a respiration rate of a patient, the method comprising:

attaching a plurality of electrocardiogram (ECG) electrodes and a pressure sensor to a patient;

detecting variations in the plurality of ECG electrodes and producing a first respiration signal based on variations detected in signals provided by the ECG electrodes attached to the patient;

detecting pressure variations in the pressure sensor and producing a second respiration signal based on pressure variations detected in the pressure sensor secured to the patient;

determining a first signal quality corresponding to the first respiration signal;

determining a second signal quality corresponding to the second respiration signal;

comparing the first signal quality to the second signal quality and selecting at least one of the first respiration signal and the second respiration signal based on the comparison of the first signal quality and the second signal quality;

producing a respiration rate from the selected signal; and

providing indicia of the respiration rate.

12. The method of claim 11, wherein producing the first respiration signal comprises:

producing an impedance signal between two or more of the ECG electrodes; and

detecting variations in the impedance signal corresponding to patient respiration.

13. The method of claim 11, wherein producing the first respiration signal comprises:

receiving ECG signals related to electrical waves that cause the patient'"'"'s heart muscle to pump; and

detecting variations in the ECG signals corresponding to patient respiration.

14. The method of claim 11, wherein attaching the plurality of ECG electrodes and the pressure sensor to the patient comprises applying an adhesive ECG electrode over the pressure sensor to temporarily secure the ECG electrode the patient'"'"'s skin, wherein the ECG electrode provides an electrical connection to the patient'"'"'s skin.

15. The method of claim 11, wherein the pressure sensor is integrated into one of the plurality of ECG electrodes, and wherein attaching the plurality of ECG electrodes and the pressure sensor to the patient comprises attaching the integrated ECG electrode and pressure sensor to the patient'"'"'s abdomen or chest.

16. The method of claim 11, wherein selecting at least one of the first respiration signal and the second respiration signal comprises:

selecting the highest quality among the first signal quality and the second signal quality.

17. The method of claim 11, wherein selecting at least one of the first respiration signal and the second respiration signal comprises:

determining that at both the first signal quality and the second signal quality are at an acceptable level; and

based on the determination, randomly selecting either the first respiration signal or the second respiration signal.

18. The method of claim 11, wherein selecting at least one of the first respiration signal and the second respiration signal comprises:

determining that both the first signal quality and the second signal quality are at an acceptable level;

determining a first respiration rate from the first respiration signal;

determining a second respiration rate from the second respiration signal; and

averaging the first respiration rate and the second respiration rate.

19. The method of claim 11, further comprising:

comparing the respiration rate to a respiration rate threshold condition; and

providing indicia of an alarm based on the comparison.

20. The method of claim 11, wherein providing the indicia comprises numerically displaying the respiration rate on a display device of a patient monitor.

21. The method of claim 11, wherein providing the indicia comprises displaying a graphical waveform representing the sequence of times corresponding to the respiration rate on a display device of a patient monitor.

22. A patient monitor comprising:

means for detecting variations in a plurality of ECG electrodes configured to attach to a patient and producing a first respiration signal based on variations detected in the ECG electrodes configured to attach to a patient;

means for detecting variations in a pressure sensor configured to attach to a patient and producing a second respiration signal based on pressure variations detected in the pressure sensor configured to attach to the patient;

means for determining a first signal quality corresponding to the first respiration signal; and

means for determining a second signal quality corresponding to the second respiration signal;

means for comparing the first signal quality to the second signal quality and selecting at least one of the first respiration signal and the second respiration signal based on the comparison of the first signal quality and the second signal quality;

means for producing a respiration rate from the selected signal; and

means for providing indicia of the respiration rate.