Non-invasive Measurement of Skin Thickness and Glucose Concentration with Raman Spectroscopy and Method of Calibration thereof

A physiological measurement system for measuring physiological data of a subject at a predetermined area of said subject's skin comprising:

• a) a Raman spectroscopic unit comprises
• (i) an excitation light source that illuminates an optical signal into said predetermined area of said subject's skin, said subject's skin further comprising a first layer and a second layer;
• and
• (ii) an optical detector that receives a Raman signal reflected from said predetermined area of said subject's skin;
• and
• b) a signal processing unit comprises
• (i) a microprocessor coupled to said optical detector
• (ii) a computer-readable storage medium coupled to said microprocessor, said computer-readable storage medium encoded with computer-readable codes to instruct said microprocessor to execute the following steps:
• i. acquiring a first data relating to the skin thickness of said first layer from said Raman signal;
• ii. acquiring a second data relating to the glucose concentration within said second layer from said Raman signal;
• iii. computing said skin thickness of said first layer based on said first data and a first prediction model;
• and
• iv. computing said glucose concentration of said second layer based on said skin thickness of said first layer, said second data, and a second prediction model.

A method of operating a physiological measurement system for measuring the thickness of a predetermined area of a subject's skin;

• said method comprising the steps of:
• a) receiving an Raman signal from said predetermined area;
• said Raman signal comprising a plurality of signal components, each said signal component identified by a wavenumber thus forming a composite Raman spectrum;
• b) identifying a first predetermined wavenumber and a second predetermined wavenumber from said Raman signal;
• c) retrieving a first intensity of said Raman signal at said first predetermined wavenumber and a second intensity of said Raman signal at said second predetermined wavenumber;
• d) calculating a ratio of said first intensity and said second intensity;
• and
• e) determining the thickness of said predetermined area of said subject's skin based on said ratio and a first prediction model,
• wherein said first prediction model comprises a functional relationship among a plurality of attributes correlating the thickness of said predetermined area and said ratio.