Portable biometric monitoring devices and methods of operating same

A portable biometric monitoring device comprising:

• a housing having a physical size and shape that is adapted to couple to a limb of the user, the housing having:
• a back surface that faces the limb when the portable biometric monitoring device is worn on the user's limb, and
• a protrusion portion that protrudes from the back surface, wherein:
• (i) the protrusion portion has a curved exterior surface that intersects the back surface in a non-tangential manner, and
• (ii) the protrusion portion is configured to engage or contact skin of the user when the portable biometric monitoring device is worn;
• at least one band, coupled to the housing, to secure the portable biometric monitoring device to the user;
• a physiological sensor, disposed in the housing, to generate data which is representative of a physiological condition of the user, the physiological sensor including:
• a first light source, disposed in the housing, to generate and output light having at least a first wavelength, and
• a photodetector, disposed in the housing, to detect scattered light;
• a first light pipe, disposed in the protrusion portion of the housing and optically coupled to the first light source, to direct or transmit light from the first light source along a predetermined path to a location on the curved exterior surface;
• and
• processing circuitry, disposed in the housing, to calculate a heart rate of the user using data which is representative of the scattered light.

A portable biometric monitoring device comprising:

• a housing having a physical size and shape that is adapted to couple to the body be worn on a limb of the user, the housing including a device body, a protrusion portion, and a gasket, wherein:
• the protrusion portion is configured to engage or contact the skin of the user when the portable biometric monitoring device is worn,
• the gasket is interposed between the protrusion portion and the device body, and
• the protrusion portion has a curved exterior surface that contacts the device body in a non-tangential manner;
• at least one band, coupled to the housing, to secure the portable biometric monitoring device to the user;
• a physiological sensor, disposed in the housing, to generate data which is representative of a physiological condition of the user, the physiological sensor including:
• a light source, disposed in the housing, to generate and output light having at least a first wavelength, and
• a photodetector, disposed in the housing, to detect scattered light;
• and
• processing circuitry, disposed in the housing, to calculate a heart rate of the user using data which is representative of the scattered light, wherein:
• the protrusion portion includes a first portion having first optical properties and a second portion having second optical properties different from the first optical properties, and
• the first portion of the protrusion portion is optically coupled to the light source so as to direct or transmit light from the light source along a predetermined path to the curved exterior surface.