Apparatus and Methods for Monitoring Physiological Data During Environmental Interference

Abstract

Apparatus and methods for attenuating environmental interference are described. A wearable monitoring apparatus includes a housing configured to be attached to the body of a subject and a sensor module that includes an energy emitter that directs energy at a target region of the subject, a detector that detects an energy response signal—or physiological condition—from the subject, a filter that removes time-varying environmental interference from the energy response signal, and at least one processor that controls operations of the energy emitter, detector, and filter.

That which is claimed is: 
     
         1 . A monitoring apparatus, comprising:
 a housing configured to be attached to a body of a subject; and   a sensor module disposed within the housing, the sensor module comprising:   a printed circuit board (PCB);   a detector attached to the PCB that detects an energy response signal from the subject in response to modulated energy directed upon a target region of the subject, wherein the energy response signal is associated with a physiological condition of the subject;   a filter that attenuates time-varying environmental interference from the energy response signal, wherein the time-varying environmental interference is from a non-physiological source external to the body of the subject and includes one or more of the following: sunlight, ambient light, airflow, and temperature; and   at least one processor that controls operations of the detector and/or filter, and that is configured to process the detected energy response signal and produce an extracted energy response signal.   
     
     
         2 . The apparatus of  claim 1 , further comprising an energy emitter attached to the PCB that directs modulated energy at a target region of the subject, wherein the energy emitter emits energy selected from the group consisting of optical energy, acoustic energy, ultrasonic energy, electromagnetic radiation, electrical energy, mechanical energy, magnetic energy, and nuclear energy. 
     
     
         3 . The apparatus of  claim 2 , wherein the energy emitter comprises at least one optical emitter selected from the group consisting of laser diodes (LDs), light-emitting diodes (LEDs), and organic light-emitting diodes (OLEDs), and wherein the detector comprises at least one optical detector. 
     
     
         4 . The apparatus of  claim 1 , wherein the physiological condition of the subject comprises one or more of the following: heart rate, pulse pressure, respiration rate, lactic threshold, blood pressure, volume of blood flow through a blood vessel, blood metabolite level, blood oxygen level, and size of at least one blood vessel. 
     
     
         5 . The apparatus of  claim 3 , wherein at least one portion of the housing comprises optically transmissive material through which light from the at least one optical emitter can pass and/or wherein at least one portion of the housing comprises material configured to attenuate light reaching the at least one optical detector at one or more selected wavelengths. 
     
     
         6 . The apparatus of  claim 1 , further comprising at least one analog-to-digital (ADC) converter that converts analog signals generated by the detector to digital signals. 
     
     
         7 . The apparatus of  claim 1 , wherein the housing comprises an earpiece configured to be attached to an ear of the subject. 
     
     
         8 . A method of monitoring at least one physiological property of a subject, comprising:
 directing modulated energy at a target region of the subject via an energy emitter;   obtaining a first energy response signal from the subject when the emitter is on;   obtaining a second energy response signal from the subject when the emitter is off; and   processing the first and second energy response signals via a filter to produce a processed energy response signal that is associated with a physiological condition of the subject, wherein the filter attenuates time-varying environmental interference from a non-physiological source external to the body of the subject and includes one or more of the following: sunlight, ambient light, airflow, and temperature.   
     
     
         9 . The method of  claim 8 , wherein directing modulated energy at a target region comprises directing at the target region energy selected from the group consisting of optical energy, acoustic energy, ultrasonic energy, electromagnetic radiation, electrical energy, magnetic energy, mechanical energy, and nuclear energy. 
     
     
         10 . The method of  claim 8 , wherein directing modulated energy at the target region comprises directing modulated light at the target region, and wherein obtaining first and second energy response signals comprises detecting light from the subject. 
     
     
         11 . The method of  claim 8 , wherein the physiological condition of the subject comprises one or more of the following: heart rate, pulse pressure, respiration rate, lactic threshold, blood pressure, volume of blood flow through a blood vessel, blood metabolite level, blood oxygen level, and size of at least one blood vessel. 
     
     
         12 . The method of  claim 8 , further comprising transmitting the processed energy response signal to a remote device. 
     
     
         13 . The method of  claim 8 , wherein the interference filter employs a spectral method to remove or attenuate motion artifacts from the processed energy response signal and/or an FIR filtering method to remove or attenuate time-varying environmental interference. 
     
     
         14 . A sensor module, comprising:
 a printed circuit board (PCB);   an optical emitter attached to the PCB;   an optical detector attached to the PCB adjacent to the optical emitter;   an optical filter overlying at least a portion of the optical detector, wherein the optical filter is configured to attenuate light at one or more selected wavelengths; and   light-opaque material adjacent to the optical detector that prevents ambient light from interfering with the optical detector.   
     
     
         15 . The sensor module of  claim 14 , wherein the optical filter has a surface area greater than a surface area of the optical detector, and wherein the optical filter overlies the optical detector such that a periphery of the optical filter overlaps a periphery of the optical detector. 
     
     
         16 . The sensor module of  claim 14 , further comprising at least one additional optical detector attached to the PCB. 
     
     
         17 . The sensor module of  claim 14 , further comprising a lens positioned above the optical emitter. 
     
     
         18 . The sensor module of  claim 14 , wherein the light-opaque material surrounding the optical emitter and optical detector such that the optical emitter and optical detector are not in direct optical communication with each other. 
     
     
         19 . The sensor module of  claim 14 , further comprising a motion sensor configured to measure movement, positional changes, or inertial changes of a wearer of the sensor module. 
     
     
         20 . A wearable monitoring apparatus, comprising:
 a substrate configured to be attached to a body of a subject; and   a sensor module attached to the substrate, the sensor module comprising:   an energy emitter that directs modulated energy at a target region of the subject;   a detector adjacent to the energy emitter that detects an energy response signal from the subject, wherein the energy response signal is associated with a physiological condition of the subject;   a filter that attenuates time-varying environmental interference from the energy response signal, wherein the time-varying environmental interference is from a non-physiological source external to the body of the subject and includes one or more of the following: sunlight, ambient light, airflow, and temperature; and   at least one processor that controls operations of the energy emitter, detector, and/or filter, and wherein the at least one processor is configured to process the detected energy response signal and produce an extracted energy response signal.   
     
     
         21 . A method of monitoring at least one physiological property of a subject, comprising:
 directing modulated energy at a target region of the subject via an energy emitter;   obtaining, via an energy detector, a first energy response signal from the subject when the emitter is on;   obtaining, via the energy detector, a second energy response signal from the subject when the emitter is off;   detecting motion information from the subject; and   processing the first and second energy response signals via a filter to produce a processed energy response signal that is associated with a physiological condition of the subject, wherein the filter attenuates time-varying environmental interference from a non-physiological source external to the body of the subject and includes one or more of the following: sunlight, ambient light, airflow, and temperature; and   processing the motion information from the subject to attenuate motion artifacts from the processed energy response signal.   
     
     
         22 . The method of  claim 21 , wherein processing the motion information comprises a spectral method.