Body-worn monitor for measuring respiration rate

• US 10,595,746 B2
• Filed: 09/14/2009
• Issued: 03/24/2020
• Est. Priority Date: 09/14/2009
• Status: Active Grant

• Current Assignee: Sotera Wireless Incorporated
• Original Assignee: Sotera Wireless Incorporated
• Inventors: Banet, Matt, McCombie, Devin, Dhillon, Marshal
• Primary Examiner(s): Weare, Meredith
• Application Number:
  US12/559,426
• Publication Number:
  US 20110066062A1
• Time in Patent Office: 3,844 Days
• Field of Search: 600484, 600529-543
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• 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 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/0535 Impedance plethysmography for measuring blood flow A61B5/0295
• CPC Class Codes: A61B 5/0809 by impedance pneumography
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/1116 Determining posture transitions
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/113 occurring during breathing
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61B 5/6823 Trunk, e.g., chest, back, abdomen, hip
• CPC Class Codes: A61B 5/6824 Arm or wrist
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/721 using a separate sensor to detect motion or using motion information derived from signals other than the physiological signal to be measured
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives
• 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

The invention provides a multi-sensor system for monitoring a patient'"'"'s respiratory rate. The system features an impedance pneumography sensor featuring at least two electrodes and a processing circuit configured to measure an impedance pneumography signal and a 3 axis accelerometer) that attaches to the patient'"'"'s torso and measures an ACC signal indicating movement of the chest or abdomen that is also sensitive to respiratory rate. The signals are collectively processed, e.g. with the adaptive filter to determine a value for the respiratory rate.

Claims

1. A body-worn system for monitoring respiratory rate from a patient, comprising:

a housing configured to be mounted on the patient'"'"'s torso;

an impedance pneumography system contained within the housing comprising;

i) a connecting portion configured to connect to a plurality of electrodes configured to be worn on the patient;

ii) a differential amplifier configured to receive electrical signals from each of the plurality of electrodes and process them to generate an analog impedance pneumography signal; and

iii) an analog-to-digital converter configured to convert the analog impedance pneumography signal into a digital impedance pneumography signal;

an accelerometer system contained within the housing comprising;

i) an accelerometer configured to generate an analog motion signal indicating movement of the chest or abdomen; and

ii) analog-to-digital converter configured to convert the analog motion signal into a digital motion signal;

a transceiver component contained within the housing configured to transmit the digital impedance pneumography signal and the digital motion signal according to a controller area network (CAN) communication protocol via a cable electrically connected thereto; and

a processing system configured to be mounted on the patient'"'"'s wrist, the processing system comprising a processor and a CAN transceiver in electrical communication with the cable and configured to receive and collectively process the digital impedance pneumography and digital motion signals to determine the patient'"'"'s respiratory rate.

2. The system of claim 1, wherein the cable comprises the housing at a terminal end thereof.

3. The system of claim 2, wherein the housing further comprises a temperature sensor.

4. The system of claim 3, wherein the temperature sensor is a thermocouple.

5. The system of claim 1, wherein the cable comprises at least one conductor configured to transmit both a first digital data stream representing the digital impedance pneumography signal or information calculated therefrom, and a second digital data stream representing the digital motion signal or information calculated therefrom.

6. The system of claim 5, wherein the first digital data stream comprises a first header portion and a first data portion, the first header portion indicating that the first data portion comprises impedance pneumography information or information calculated therefrom.

7. The system of claim 5, wherein the first digital data stream comprises a first header portion and a first data portion, the first header portion indicating that the first data portion comprises motion information or information calculated therefrom.

8. The system of claim 1, wherein the system further comprises an ECG system for measuring heart rate from the patient.

9. The system of claim 8, wherein the ECG and impedance pneumography systems are contained within a single integrated circuit.

10. The system of claim 8, wherein the ECG system is selected from the group consisting of a three electrode, a five electrode, and a twelve electrodes ECG system.

11. The system of claim 1, wherein the processing system further comprises a display configured to render impedance pneumography information.

12. The system of claim 11, the display is further configured to render at least one of respiratory rate and a time-dependent waveform indicating respiratory rate.

13. The system of claim 1, wherein the impedance pneumography system is contained within a single integrated circuit.