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

A user-worn device comprising:

• a first set of light emitting diodes (LEDs), the first set of LEDs comprising at least an LED configured to emit light at a first wavelength and an LED configured to emit light at a second wavelength;
• a second set of LEDs spaced apart from the first set of LEDs, the second set of LEDs comprising at least an LED configured to emit light at the first wavelength and an LED configured to emit light at the second wavelength;
• four photodiodes arranged on a surface and configured to receive light after at least a portion of the light has been attenuated by tissue of a user;
• a protrusion arranged above the surface, the protrusion comprising a convex surface including windows, the windows extending across the four photodiodes, wherein light passes through the protrusion to the four photodiodes via at least the windows;
• a thermistor configured to provide a temperature signal;
• and
• one or more processors configured to:
• receive one or more signals from at least one of the photodiodes;
• receive the temperature signal;
• and
• adjust operation of the user-worn device responsive to the temperature signal.

A user-worn device configured to non-invasively determine measurements of a physiological parameter of a user, the user-worn device comprising:

• a first set of light emitting diodes (LEDs), the first set comprising at least an LED configured to emit light at a first wavelength and at least an LED configured to emit light at a second wavelength;
• a second set of LEDs spaced apart from the first set of LEDs, the second set of LEDs comprising an LED configured to emit light at the first wavelength and an LED configured to emit light at the second wavelength;
• four photodiodes;
• a protrusion comprising a convex surface, at least a portion of the protrusion comprising an opaque material;
• a plurality of openings provided through the protrusion and the convex surface, the openings aligned with the photodiodes;
• a separate optically transparent window extending across each of the openings;
• one or more processors configured to receive one or more signals from at least one of the photodiodes and output measurements of a physiological parameter of a user;
• a housing;
• and
• a strap configured to position the housing proximate tissue of the user when the device is worn.

A user-worn device configured to non-invasively determine measurements of a user's tissue, the user-worn device comprising:

• a plurality of light emitting diodes (LEDs);
• at least four photodiodes configured to receive light emitted by the LEDs, the four photodiodes being arranged to capture light at different quadrants of tissue of a user;
• a protrusion comprising a convex surface and a plurality of through holes, each through hole including a window and arranged over a different one of the at least four photodiodes;
• and
• one or more processors configured to receive one or more signals from at least one of the photodiodes and determine measurements of oxygen saturation of the user.