Patient monitoring system using wearable sensors with automated template matching

Abstract

A wearable patient monitoring device in a patient monitoring system includes motion sensors generating sensor output signals in response to sensed patient motion, and a processor that processes the sensor output signals according to a template-matching monitoring process that includes (1) detecting occurrence of a first event of a multi-event movement based on first values of the sensor output signals, the multi-event movement having a finite-state-machine (FSM) representation as a sequence of states corresponding to events and expected values of the sensor output signals of the multi-event movement, (2) detecting occurrence of remaining events of the multi-event movement based on a sequence of subsequent values of the sensor output signals, and (3) upon detecting a last event of the multi-event movement, generating an output signal indicating detection of the patient performing the multi-event movement. Communications circuitry communicates the detection to a higher-level computerized device of the patient monitoring system.

What is claimed is: 
     
         1 . A wearable patient monitoring device for use in a patient monitoring system, comprising:
 one or more motion sensors generating respective sensor output signals in response to sensed motion of a patient wearing the patient monitoring device; and   a processor coupled to receive and process the sensor output signals according to a template-matching monitoring process including:
 detecting occurrence of a first event of a multi-event movement based on first values of the sensor output signals, the multi-event movement having a finite-state-machine (FSM) representation as a sequence of states corresponding to respective events and associated expected values of the sensor output signals of the multi-event movement; 
 subsequently detecting occurrence of remaining events of the multi-event movement based on a sequence of subsequent values of the sensor output signals matching the expected values of the sensor output signals in the FSM representation of the multi-event movement; and 
 upon detecting a last event of the multi-event movement, generating an output signal indicating detection of the patient performing the multi-event movement; and 
   communications circuitry configured and operative in response to the output signal to communicate the detection of the patient performing the multi-event movement to a higher-level computerized device of the patient monitoring system.   
     
     
         2 . The wearable patient monitoring device of  claim 1 , wherein the events are transitions between respective configurations of the patient's body, the configurations including (1) prone, (2) seated, and (3) standing. 
     
     
         3 . The wearable patient monitoring device of  claim 2 , wherein the transitions include prone-to-seated and seated-to-standing. 
     
     
         4 . The wearable patient monitoring device of  claim 1 , wherein the motion sensors include rotational sensors for sensing rotation about one or more axes of the patient's body. 
     
     
         5 . The wearable patient monitoring device of  claim 4 , wherein the rotational sensors sense rotation about a pitch axis, a roll axis, and a yaw axis of the patient's body. 
     
     
         6 . The wearable patient monitoring device of  claim 1 , employing a modified FSM to detect events in real time, with transitions between the states being defined based on phases of the sensor signals rather than any specific sub-movement. 
     
     
         7 . The wearable patient monitoring device of  claim 6 , wherein the communications circuitry is further configured and operative to relay alerts in real-time to an application on an attendant's device or a monitoring station.