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.

What is claimed is: 
     
         1 . A monitoring network for measuring and displaying vital sign information from an ambulatory patient within a hospital, comprising:
 a sensor module configured to attach to the patient's chest, comprising (i) at least three electrodes configured to attach to the patient's chest, (ii) an electrocardiogram (ECG) module configured to receive signals from the at least three electrodes and generate digital ECG waveforms corresponding to the signal received from each lead, (iii) an impedance module configured to inject a current into one of the at least three electrodes, measure a current modulated by capacitance changes in the patient's chest at a different one of the at least three electrodes, and generate a digital impedance waveform from the measured current, (iv) an accelerometer module configured to generate digital motion waveforms corresponding to an x-, y-, and z-axis of the accelerometer, (iv) a temperature module configured to measure a skin temperature for the patient and generate a digital temperature signal, and (v) a first transceiver configured to transmit the digital ECG waveforms, the digital impedance waveform, the digital motion waveforms, and the digital temperature signal as separate digital data packet streams along a single transmission path;   a processing module configured to attach to the patient's arm, comprising (i) a second transceiver configured to receive the digital ECG waveforms, the digital impedance waveform, the digital motion waveforms, and the digital temperature signal, and (ii) a transmitter configured to transmit the digital ECG waveforms, the digital impedance waveform, the digital motion waveforms, and the digital temperature signal wirelessly to an access point within a hospital wireless network;   a remote display device operably connected to the hospital wireless network and configured to receive and display the digital ECG waveforms, the digital impedance waveform, the digital motion waveforms, and the digital temperature signal,   wherein the processing module transmits a synchronization packet to the sensor module to establish a phase-locked state for data transmission between the sensor module and the processing module having a maximum 40 microsecond timing error.   
     
     
         2 . A hospital monitoring network according to  claim 1 , further comprising a photoplethysmogram (PPG) module configured to attach to a finger of the patient, generate a PPG waveform, and transmit the PPG waveform to the processing module. 
     
     
         3 . A hospital monitoring network according to  claim 1 , wherein the processing module is configured to determine a heart rate and a respiration rate using the digital ECG waveforms and the digital impedance waveform. 
     
     
         4 . A hospital monitoring network according to  claim 2 , wherein
 the processing module is configured to continuously determine a heart rate and a respiration rate using the digital ECG waveforms and the digital impedance waveform, and continuously determine an SpO2 value from the PPG waveform, and to transmit the continuous heart rate, respiration rate, and SpO2 value wirelessly to the access point; and   the remote display is configured to receive and display the continuous heart rate, respiration rate, and SpO2 value.   
     
     
         5 . A hospital monitoring network according to  claim 1 , wherein the first and second transceivers operate according to the CAN protocol. 
     
     
         6 . A hospital monitoring network according to  claim 2 , wherein the first and second transceivers operate according to the CAN protocol. 
     
     
         7 . A hospital monitoring network according to  claim 3 , wherein the first and second transceivers operate according to the CAN protocol. 
     
     
         8 . A hospital monitoring network according to  claim 4 , wherein the first and second transceivers operate according to the CAN protocol.