Body-worn vital sign monitor

Abstract

The invention provides a body-worn vital sign monitor that measures a patient's vital signs (e.g. blood pressure, SpO2, heart rate, respiratory rate, and temperature) while simultaneously characterizing their activity state (e.g. resting, walking, convulsing, falling) and posture (upright, supine). The monitor processes this information to minimize corruption of the vital signs and associated alarms / alerts by motion-related artifacts. It also features a graphical user interface (GUI) rendered on a touchpanel display that facilitates a number of features to simplify and improve patient monitoring and safety in both the hospital and home.

Description

CROSS REFERENCES TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. Provisional Application No. 61 / 312,624, filed Mar. 10, 2010, entitled “BODY-WORN VITAL SIGN MONITOR”, which is incorporated herein in its entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not ApplicableBACKGROUND OF THE INVENTION[0003]1. Field of the Invention[0004]The present invention relates to medical devices for monitoring vital signs, e.g., arterial blood pressure.[0005]2. Description of the Related Art[0006]Conventional vital sign monitors are used throughout the hospital, and are particularly commonplace in high-acuity areas such as the intensive care unit (ICU), emergency department (ED), or operating room (OR). Patients in these areas are generally sick and require a high degree of medical attention, typically provided by a relatively high ratio of clinicians compared to lower-acuity areas of the hospital. Outside the ICU and OR, clinicians typically measur...

AI Technical Summary

Benefits of technology

[0012]To improve the safety of hospitalized patients, particularly those in lower-acuity areas, it is desirable to have a body-worn monitor that continuously measures all vital signs from a patient, provides tools for effectively monitoring the patient, and wirelessly communicates with a hospital's information technology (IT) network. Preferably the monitor operates algorithms featuring: 1) a low percentage of false positive alarms / alerts; and 2) a high percentage of true positive alarms / alerts. The term ‘alarm / alert’, as used herein, refers to an audio and / or visual alarm generated directly by a monitor worn on the patient's body, or alternatively a remote monitor (e.g., a central nursing station). To accomplish this, the invention provides a body-worn monitor that measures a patient's vital signs (e.g. cNIBP, SpO2, HR, RR, and TEMP) while simultaneously characterizing their activity state (e.g. resting, walking, convulsing, falling) and posture (upright, supine). The body-worn monitor processes this information to minimize corruption of the vital signs and associated alarms / alerts by motion-related artifacts.

[0013]The body-worn monitor features a graphical user interface (GUI) rendered on a touchpanel display that facilitates a number of features to simplify and improve patient monitoring and safety in both the hospital and home. For example, the monitor features a battery-powered, wrist-worn transceiver that processes motion-related signals generated with an internal motion sensor (e.g. an accelerometer). When the transceiver's battery runs low, the entire unit can be swapped out by simply ‘bumping’ the original transceiver with a new one having a fully charged battery. Accelerometers within the transceivers detect the ‘bump’, digitize the corresponding signals, and wirelessly transmit them to a patient data server (PDS) within the hospital's network. There, the signals are analyzed and patient information (e.g. demographic and vital sign data) formerly associated with the original transceiver is re-associated with the new transceiver. A clinician can view the data using a computer functioning as a remote viewing device (RVD), such as a conventional computer on wheels (COW).

[0017]The wrist-worn transceiver's touchpanel display can render a variety of different GUIs that query the patient for their pain level, test their degree of ‘mentation’, i.e. mental activity, and perform other functions to assist and improve diagnosis. Additionally, the transceiver supports other GUIs that allow the patient to order food within the hospital, change the channel on their television, select entertainment content, play games, etc. To help promote safety in the hospital, the GUI can also render a photograph or video of the patient or, in the case of neo-natal patients, their family members.

[0019]The body-worn monitor features a series of sensors that attach to the patient to measure time-dependent PPG, ECG, ACC, oscillometric (OSC), and impedance pneumography (IP) waveforms. A microprocessor (CPU) within the monitor continuously processes these waveforms to determine the patient's vital signs, degree of motion, posture and activity level. Sensors that measure these signals typically send digitized information to the wrist-worn transceiver through a serial interface, or bus, operating on a controlled area network (CAN) protocol. The CAN bus is typically used in the automotive industry, and allows different electronic systems to effectively and robustly communicate with each other with a small number of dropped packets, even in the presence of electrically noisy environments. This is particularly advantageous for ambulatory patients that may generate signals with large amounts of motion-induced noise.

Problems solved by technology

It can be difficult to effectively monitor patients in this way, however, because measurements are typically made every few hours, and the patients are often ambulatory and not constrained to a single hospital room.

This poses a problem for conventional vital sign monitors, which are typically heavy and unwieldy, as they are not intended for the ambulatory population.

Some companies have developed ambulatory vital sign monitors with limited capabilities (e.g. cuff-based blood pressure using oscillometry and SpO2 monitoring), but typically these devices only make intermittent, rather than continuous, measurements.

And even these measurements tend to work best on stationary patients, as they are easily corrupted by motion-related artifacts.

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