System and method for reducing false alarms associated with vital-signs monitoring

• US 9,055,925 B2
• Filed: 07/27/2010
• Issued: 06/16/2015
• Est. Priority Date: 07/27/2010
• Status: Active Grant

• Current Assignee: Carefusion 303 Incorporated (Becton, Dickinson & Co)
• Original Assignee: Carefusion 303 Incorporated (Becton, Dickinson & Co)
• Inventors: Paquet, Pierre, Lewis, Stephen
• Primary Examiner(s): Thomson, William
• Assistant Examiner(s): Archer, Marie
• Application Number:
  US12/844,794
• Publication Number:
  US 20120029314A1
• Time in Patent Office: 1,785 Days
• Field of Search: 600300-301, 600306-309, 600/316, 600/323, 600/324, 600/339, 600/341, 600/344, 600/333, 600/357, 600363-365, 600372-374, 600377-379, 600382-384, 600386-394, 600/481, 600/485, 600500-503, 600/508, 600515-519, 600529-531, 600544-547, 600/549, 600587-595, 705 2- 3, 128920-925
• US Class Current: 1/1
• CPC Class Codes: A61B 2560/0412 Low-profile patch shaped housings
• CPC Class Codes: A61B 2560/0475 Special features of memory means, e.g. removable memory cards
• 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 5/0008 Temperature signals
• CPC Class Codes: A61B 5/002 Monitoring the patient using a local or closed circuit, e.g. in a room or building A61B5/0017 takes precedence
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/02055 Simultaneously evaluating both cardiovascular condition and temperature
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/6833 Adhesive patches
• CPC Class Codes: A61B 5/72 Signal processing specially adapted for physiological signals or for diagnostic purposes character recognition, recognising digital ink, document-oriented image-based pattern recognition G06V30/00; recognition or understanding of postal images G06V30/424
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take 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
• CPC Class Codes: G08B 21/0211 Combination with medical sensor, e.g. for measuring heart rate, temperature
• CPC Class Codes: G08B 25/006 Alarm destination chosen according to type of event, e.g. in case of fire phone the fire service, in case of medical emergency phone the ambulance
• CPC Class Codes: G16H 40/67 for remote operation

Abstract

Systems and methods of reducing false alarms associated with a vital-sign monitor are disclosed. One or more data samples of a vital sign of a patient are generated at a first sampling rate in a normal mode of operation. Whether the one or more data samples satisfy an alert condition is determined. An alert mode of operation is entered into if the alert condition is satisfied. One or more additional data samples of the vital sign are generated at a second sampling rate higher than the first sampling rate in the alert mode.

Claims

1. A method of reducing false alarms associated with vital-sign monitoring, the method comprising the steps of:

generating a plurality of data samples of a single vital sign of a patient during each of a series of normal measurement intervals in a normal mode of operation;

converting the plurality of data samples generated during each of the series of normal measurement intervals to a single normal parameter value associated with the respective one of the series of normal measurement intervals;

entering an alert mode of operation if the normal parameter value that is associated with the most recent of the series of normal measurement intervals is equal to or outside of a first threshold limit;

generating a plurality of data samples of the single vital sign during one or more sequential alert measurement intervals while in the alert mode, an alert measurement interval being shorter than a normal measurement interval;

converting the plurality of data samples generated during each of the one or more sequential alert measurement intervals to a single alert parameter value associated with the respective one of the one or more sequential alert measurement intervals; and

providing a first alarm notification if a first alert parameter value is equal to or outside of a second threshold limit and a second alert parameter value is further outside the second threshold limit than the first alert parameter value, wherein the second alert parameter value is associated with an alert measurement interval that is immediately subsequent to the alert measurement interval associated with the first alert parameter value.

2. The method of claim 1, further comprising the step of:

switching from the alert mode to the normal mode when a first predetermined number of most recent sequential alert parameter values are within the first threshold limit.

3. The method of claim 1, further comprising the step of:

wirelessly sending the single normal parameter value to a surveillance server while in the normal mode.

4. The method of claim 3, further comprising the step of:

wirelessly sending the single alert parameter value to a surveillance server while in the alert mode.

5. The method of claim 1, wherein the steps associated with generating a plurality of data samples, converting the plurality of data samples to the single normal or the single alert parameter value, entering an alert mode of operation, and providing an alarm notification are performed by a processor in a wireless vital-sign monitor patch.

6. The method of claim 1, further comprising the step of:

entering an alarm condition when a second predetermined number of most recent sequential alert parameters are rising consecutively.

7. The method of claim 6, further comprising the step of:

providing a second alarm notification when the alarm condition is entered.

8. A vital-sign monitor, comprising:

at least one sensor configured to generate a plurality of data samples of a single vital sign of a patient at a first sampling rate in a normal mode of operation;

a memory configured to store commands;

a processor configured to execute the commands stored in the memory, and upon execution of the commands, to cause the vital-sign monitor to;

convert the plurality of data samples generated at the first sampling rate to a single normal parameter value;

enter an alert mode if the single normal parameter value is equal to or outside of a first threshold limit;

generate with the at least one sensor a plurality of data samples of the single vital sign at a second sampling rate higher than the first sampling rate while in the alert mode; and

convert the plurality of data samples generated at the second sampling rate to a single alert parameter value; and

a wireless transceiver configured to provide an alarm notification to a surveillance server when a first alert parameter value is equal to or outside of a second threshold limit and a second alert parameter value immediately subsequent to the first alert parameter value is further outside the second threshold limit than the first alert parameter value, the wireless transceiver further configured to provide to the surveillance server the single normal parameter value while in the normal mode and the single alert parameter value while in the alert mode.

9. The vital-sign monitor of claim 8, wherein the vital-sign monitor is a wireless vital-sign monitor patch.

10. The vital-sign monitor of claim 8, wherein the at least one sensor comprises at least one of a body temperature sensor, a pulse rate sensor, a blood pressure sensor, and a respiratory rate sensor.

11. The vital-sign monitor of claim 8, wherein the processor is further configured to switch the at least one sensor from the alert mode to the normal mode when a predetermined number of the most recent alert parameter values are within the first threshold limit.

12. The vital-sign monitor of claim 8, wherein the wireless transceiver comprises a digital-to-analog converter configured to receive data from the processor and to generate a first base signal and an analog-to-digital converter configured to provide a digitized second base signal to the processor.

13. The vital-sign monitor of claim 8, wherein:

the vital-sign monitor is part of a vital-sign monitoring system, the system comprising;

a bridge configured to wirelessly receive the alert parameter values from the vital-sign monitor and provide the alert parameter values; and

the surveillance server, wherein the surveillance server is configured to communicate with the vital-sign monitor wirelessly through a bridge.

14. The vital-sign monitor of claim 13, wherein:

the bridge is further configured to receive and provide the single normal parameter value; and

the surveillance server is further configured to receive the single normal parameter value and send the single normal parameter value to the hospital system.

15. The vital-sign monitor of claim 8, wherein the processor is further configured to cause the wireless transceiver to transmit an alarm condition to the surveillance server when a second predetermined number of most recent sequential alert parameters are rising consecutively.

16. A method for providing an alarm in a vital-sign monitoring system, the method comprising the steps of:

causing a sensor in a vital sign monitor patch to measure a vital sign at a first frequency;

causing the sensor to measure the vital sign at a second frequency greater than the first frequency when the vital sign exceeds a first threshold while measuring the vital sign at the first frequency;

entering an alert mode of operation when the measured vital sign exceeds the first threshold while measuring the vital sign at the first frequency; and

causing a wireless transceiver to provide an alarm notification to a surveillance server when the measured vital sign initially exceeds a second threshold greater than the first threshold during a first time period while measuring the vital sign at the second frequency and the measured vital sign during a second time period of measuring the vital sign at the second frequency subsequent to the first time period exceeds the second threshold to a greater extent than the measured vital sign of the first time period.

17. The method of claim 16, further comprising selecting the second time period contiguous to the first time period.

18. The method of claim 16, further comprising selecting the first and second thresholds as upper limits and selecting the second threshold greater than the first threshold.

19. The method of claim 16, further comprising selecting the first and second thresholds as lower limits and selecting the second threshold lower than the first threshold.