Body-worn vital sign monitor

• US 10,420,476 B2
• Filed: 09/15/2009
• Issued: 09/24/2019
• Est. Priority Date: 09/15/2009
• Status: Active Grant

• Current Assignee: Sotera Wireless Incorporated
• Original Assignee: Sotera Wireless Incorporated
• Inventors: Moon, Jim, Visser, Henk, Hunt, Robert
• Primary Examiner(s): Weare, Meredith
• Application Number:
  US12/560,138
• Publication Number:
  US 20110066010A1
• Time in Patent Office: 3,661 Days
• Field of Search: 600300, 600301, 600481, 4554561-4566, 34053912, 34053921, 3405731, 34028601, 34028606, 34028607
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 2562/043 in a linear array
• 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 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02125 of pulse wave propagation time
• CPC Class Codes: A61B 5/02225 using the oscillometric method
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• 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 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• 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 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 5/7495 using a reader or scanner device, e.g. barcode scanner

Abstract

The invention provides a body-worn monitor featuring a processing system that receives a digital data stream from an ECG system. A cable houses the ECG system at one terminal end, and plugs into the processing system, which is worn on the patient'"'"'s wrist like a conventional wristwatch. The ECG system features: i) a connecting portion connected to multiple electrodes worn by the patient; ii) a differential amplifier that receives electrical signals from each electrode and process them to generate an analog ECG waveform; iii) an analog-to-digital converter that converts the analog ECG waveform into a digital ECG waveform; and iv) a transceiver that transmits a digital data stream representing the digital ECG waveform (or information calculated from the waveform) through the cable and to the processing system. Different ECG systems, typically featuring three, five, or twelve electrodes, can be interchanged with one another.

Claims

1. A system for monitoring vital signs from a group of patients, comprising:

(a) a monitoring device configured to be worn on the body of each patient in the group, each monitoring device comprising;

a wireless system;

a first sensor configured to generate a first time-dependent waveform indicative of one or more contractile properties of the patient'"'"'s heart;

a second sensor configured to generate a second time-dependent waveform indicative of one or more contractile properties of the patient'"'"'s heart; and

a processing component configured to;

(i) receive a first signal representing the first time-dependent waveform;

(ii) receive a second signal representing the second time-dependent waveform;

(iii) calculate a blood pressure value from a pulse transit time measured between the first and second signals or versions thereof; and

(iv) transmit the blood pressure value with the wireless system; and

(b) a remote display device in communication with each monitoring device through the wireless system comprised by the monitoring device, the remote display device configured to simultaneously display a blood pressure value for each patient in the group when a signal strength corresponding to the wireless system comprised by each monitoring device is below a pre-determined threshold value, and further configured to automatically reconfigure the display device to display a blood pressure value for only a particular patient when the signal strength from the wireless system worn by the particular patient exceeds the pre-determined threshold.

2. The system of claim 1, wherein the signal strength represents a magnitude of a wireless signal transmitted from a monitoring device.

3. The system of claim 2, wherein the pre-determined threshold value is between −

100 and −

80 dB.

4. The system of claim 1, wherein the wireless system comprised by each monitoring device operates on a protocol selected from 802.11, 802.15.4, and cellular wireless protocols.

5. The system of claim 4, wherein the remote display device is further configured to simultaneously communicate with each monitoring device through a wireless network when the signal strength corresponding to the wireless system comprised by each monitoring device is below the pre-determined threshold value.

6. The system of claim 5, wherein the wireless network is a peer-to-peer wireless connection.

7. The system of claim 1, wherein the remote display comprises a first user interface configured to simultaneously display a blood pressure value for each patient in the group.

8. The system of claim 7, wherein the first user interface comprises separate fields for displaying the first time-dependent waveform and the blood pressure value for each patient in the group.

9. The system of claim 8, wherein the first time-dependent waveform is an ECG waveform.

10. The system of claim 8, wherein each monitoring device further includes a motion-detecting sensor, and the processing component of each monitoring device is further configured to analyze a signal from the motion-detecting sensor to determine at least one of a posture, activity level, and degree of motion corresponding to the patient wearing the monitoring device.

11. The system of claim 10, wherein the first user interface comprises a separate field for displaying at least one of the posture, activity level, and degree of motion corresponding to each patient wearing the monitoring device.

12. The system of claim 7, wherein the processing component of each monitoring device is further configured to analyze wireless signals from at least one wireless base station to estimate a location of the monitoring device.

13. The system of claim 12, wherein the processing component of each monitoring device is further configured to transmit the estimated location to the remote display through the wireless system.

14. The system of claim 13, wherein the first user interface comprises a separate field for displaying a location corresponding to each patient wearing the monitoring device.

15. The system of claim 14, wherein the separate field comprises a map for simultaneously displaying the location corresponding to each patient wearing the monitoring device.

16. The system of claim 1, wherein the wireless system comprised by each monitoring device further comprises a voice interface to the remote display device.

17. The system of claim 16, wherein the voice interface operates on a VOIP protocol.

18. The system of claim 1, wherein the remote device is a computer.

19. The system of claim 18, wherein the computer is selected from the group consisting of a desktop computer, a portable computer, a tablet computer, a cellular telephone, or a personal digital assistant.