Optical sensor and methods of initialising and calibrating an optical sensor

An optical sensor for measuring one or more physiological signs of a person, the optical sensor comprising:

• one or more detectors;
• and
• one or more light sources,
• wherein once the device is attached to the person, the optical sensor is configured to:
• emit light pulses at a plurality of different wavelengths using one or more light sources, wherein each light pulse at each wavelength is emitted at a known power level and for a known length time;
• record a signal for the light pluses at each wavelength using the one or more detectors to create an optical signature of the person;
• and
• select one or more wavelengths of the plurality of wavelengths based on the optical signature of the person to be used when measuring the one or more physiological signs.

A method of initialising an optical sensor for measuring one or more physiological signs of a person, the sensor comprising one or more detectors and one more light sources, the method comprising the following steps before the device is attached to the person:

• emitting one or more light pulses at one or more different wavelengths using the one or more light sources, wherein each light pulse is emitted at a known power level for a known length of time;
• recording the signal for the one or more light pulses at each wavelength using the one or more detectors;
• determining a parameter for each signal at each wavelength of light;
• comparing the determined parameter to a stored value of the parameter for each wavelength;
• and
• determining that the optical sensor is ready for use if the determined parameter for each wavelength is within a set tolerance of the stored value of the parameter for each wavelength.

A method of calibrating an optical sensor for measuring one or more physiological signs of a person, the sensor comprising one or more detectors and one or more light sources, the method comprising the following steps after the device is attached to the person:

• emitting one or more light pulses at one or more wavelengths using one or more of the one or more light sources, wherein each light pulse at each wavelength is emitted at a known power level and for a known length time;
• recording a signal for the one or more light pluses at each wavelength using the one or more detectors;
• determining a parameter for each signal at each wavelength of light;
• comparing the determined parameter to a stored value of the parameter for each wavelength of light;
• and
• adjusting the power and/or length of time of the one or more light pulses at each wavelength to reduce the difference between the determined parameter and the stored value of the parameter.