User-worn device for noninvasively measuring a physiological parameter of a user

Abstract

The present disclosure relates to noninvasive methods, devices, and systems for measuring various blood constituents or analytes, such as glucose. In an embodiment, a light source comprises LEDs and super-luminescent LEDs. The light source emits light at at least wavelengths of about 1610 nm, about 1640 nm, and about 1665 nm. In an embodiment, the detector comprises a plurality of photodetectors arranged in a special geometry comprising one of a substantially linear substantially equal spaced geometry, a substantially linear substantially non-equal spaced geometry, and a substantially grid geometry.

1 . (canceled) 
     
     
         2 . A user-worn device configured to non-invasively measure a physiological parameter of a user, the user-worn device comprising:
 a plurality of light emitting diodes (LEDs) configured to emit light;   one or more photodiodes configured to receive light after attenuation by tissue of the user; and   one or more processors configured to:
 cause at least a first one of the plurality of LEDs to be driven at a first power; 
 cause at least a second one of the plurality of LEDs to be driven at a second power, wherein the second power is a higher power than the first power; 
 receive one or more signals from at least one of the photodiodes; and 
 responsive to the one or more signals, calculate a measurement of the physiological parameter of the user, wherein the one or more signals include information responsive to light received from both the first and second ones of the plurality of LEDs after attenuation by tissue, and wherein the one or more processors are configured to reduce noise or increase a signal-to-noise ratio based on the one or more signals. 
   
     
     
         3 . The user-worn device of  claim 2 , wherein the second one of the plurality of LEDs is driven at the second power after the first one of the plurality of LEDs is driven at the first power such that the plurality of LEDs is driven using a progression from low power to the higher power. 
     
     
         4 . The user-worn device of  claim 3 , wherein an order of driving the first and second ones of the plurality of LEDs is based on the progression from low power to the higher power. 
     
     
         5 . The user-worn device of  claim 3 , wherein the progression from low power to the higher power comprises an increase in power of between 40 times and 100 times. 
     
     
         6 . The user-worn device of  claim 5 , wherein the progression from low power to the higher power comprises an increase in power of between 40 times and 50 times. 
     
     
         7 . The user-worn device of  claim 3  further comprising:
 an LED driver configured to provide pulses of current to the plurality of LEDs, wherein the LED driver receives a control signal from the one or more processors and in response drives the plurality of LEDs progressing from low power to the higher power. 
 
     
     
         8 . The user-worn device of  claim 7 , wherein the progression from low power to the higher power comprises:
 a first one or more pulses at low power; and   a second one or more pulses at the higher power.   
     
     
         9 . The user-worn device of  claim 8 , wherein:
 the first one of the plurality of LEDs emits the first one or more pulses at a first one or more wavelengths, and   the second one of the plurality of LEDs emits the second one or more pulses at a second one or more wavelengths different from the first one or more wavelengths.   
     
     
         10 . The user-worn device of  claim 7 , wherein the progression from low power to the higher power allows the LED driver to stabilize and provide more stable current to the plurality of LEDs. 
     
     
         11 . The user-worn device of  claim 2 , wherein:
 the first one of the plurality of LEDs emits light at a first wavelength, and   the second one of the plurality of LEDs emits light at a second wavelength different from the first wavelength.   
     
     
         12 . The user-worn device of  claim 11 , wherein the one or more processors are further configured to:
 cause the first one of the plurality of LEDs to be driven for a first quantity of time slots, and   cause the second one of the plurality of LEDs to be driven for a second quantity of time slots, wherein the first quantity is different from the second quantity.   
     
     
         13 . The user-worn device of  claim 12 , wherein the second wavelength is longer than the first wavelength, and wherein the second quantity is greater than the first quantity. 
     
     
         14 . The user-worn device of  claim 12 , wherein the first quantity of time slots does not overlap with the second quantity of time slots. 
     
     
         15 . The user-worn device of  claim 11 , wherein the first one of the plurality of LEDs is driven during different time slots than the second one of the plurality of LEDs. 
     
     
         16 . The user-worn device of  claim 3 , wherein the increased signal-to-noise ratio of the user-worn device is sufficient for detecting a blood analyte. 
     
     
         17 . The user-worn device of  claim 16 , wherein the measurement of the physiological parameter is based on a detection of the blood analyte. 
     
     
         18 . The user-worn device of  claim 2 , wherein the one or more processors are further configured to:
 cause modulation of a duty cycle for driving the plurality of LEDs at the first and second powers, wherein the modulation includes pulse width time slots and off time slots.   
     
     
         19 . The user-worn device of  claim 2  further comprising:
 a user interface comprising a touch-screen display, wherein the user interface is configurable to display indicia responsive to the measurement of the physiological parameter; 
 a storage device configured to at least temporarily store at least the measurement; and 
 a strap configured to position the user-worn device on the user. 
 
     
     
         20 . The user-worn device of  claim 2 , wherein the physiological parameter comprises at least one of: methemoglobin, total hemoglobin, carboxyhemoglobin, or carbon monoxide. 
     
     
         21 . The user-worn device of  claim 2 , wherein the physiological parameter comprises oxygen or oxygen saturation. 
     
     
         22 . The user-worn device of  claim 2 , wherein the physiological parameter comprises trending information. 
     
     
         23 . The user-worn device of  claim 2 , wherein the physiological parameter comprises glucose. 
     
     
         24 . The user-worn device of  claim 2 , wherein the LEDs and the photodiodes are arranged on a same side of the tissue of the user. 
     
     
         25 . The user-worn device of  claim 2  further comprising:
 a front-end interface comprising one or more amplifiers and one or more analog to digital converters (ADCs), wherein the front-end interface receives the signals from the photodiodes, the one or more amplifiers amplify the signals and the one or more ADCs convert the signals to digital information, and wherein the one or more processors receive the converted signals. 
 
     
     
         26 . A physiological measurement system comprising:
 a user-worn device according to  claim 2 ; and   a mobile phone configured to wirelessly communicate with the user-worn device.   
     
     
         27 . A user-worn device configured to non-invasively measure a physiological parameter of a user, the user-worn device comprising:
 a plurality of light emitting diodes (LEDs) configured to emit light;   one or more photodiodes configured to receive light after attenuation by tissue of the user;   a network interface configured to provide wireless communication with at least one of a mobile phone or a computer network;   one or more processors configured to:
 cause at least a first one of the plurality of LEDs to be driven at a first power for a first quantity of time slots; 
 cause at least a second one of the plurality of LEDs to be driven at a second power for a second quantity of time slots, wherein the first quantity is different from the second quantity, wherein the second power is a higher power than the first power, wherein the first quantity of time slots does not overlap with the second quantity of time slots, and wherein the second one of the plurality of LEDs is driven at the second power after the first one of the plurality of LEDs is driven at the first power such that the plurality of LEDs is driven using a progression from low power to the higher power; 
 receive one or more signals from at least one of the photodiodes; and 
 responsive to the one or more signals, calculate a measurement of the physiological parameter of the user, wherein the one or more signals include information responsive to light received from both the first and second ones of the plurality of LEDs after attenuation by tissue, and wherein the one or more processors are configured to reduce noise or increase a signal-to-noise ratio based on the one or more signals; and 
   an LED driver configured to provide pulses of current to the plurality of LEDs, wherein the LED driver receives a control signal from the one or more processors and in response drives the plurality of LEDs progressing from low power to the higher power,
 wherein:
 the progression from low power to the higher power comprises a first one or more pulses at low power and a second one or more pulses at the higher power, 
 the first one of the plurality of LEDs emits the first one or more pulses at a first one or more wavelengths and the second one of the plurality of LEDs emits the second one or more pulses at a second one or more wavelengths different from the first one or more wavelengths, and 
 the progression from low power to the higher power allows the LED driver to stabilize and provide more stable current to the plurality of LEDs. 
 
   
     
     
         28 . The user-worn device of  claim 27  further comprising:
 a user interface comprising a touch-screen display, wherein the user interface is configurable to display indicia responsive to the measurement of the physiological parameter; 
 a storage device configured to at least temporarily store at least the measurement; and 
 a strap configured to position the user-worn device on the user. 
 
     
     
         29 . The user-worn device of  claim 24 , wherein the LEDs and the photodiodes are arranged on a same side of the tissue of the user. 
     
     
         30 . The user-worn device of  claim 25  further comprising:
 a front-end interface comprising one or more amplifiers and one or more analog to digital converters (ADCs), wherein the front-end interface receives the signals from the photodiodes, the one or more amplifiers amplify the signals and the one or more ADCs convert the signals to digital information, and wherein the one or more processors receive the converted signals. 
 
     
     
         31 . A physiological measurement system comprising:
 a user-worn device according to  claim 27 ; and   a mobile phone configured to wirelessly communicate with the user-worn device.