Method of removing abnormal data and blood component spectroscopy analysis system employing the same

A tangible, non-transitory computer-readable recording medium in a blood component analysis system using spectroscopy to estimate a concentration of a blood component by analyzing a photo-plethysmographic (PPG) signal obtained by radiating light of first and second wavelengths reacting to the blood component on a subject and detecting light corresponding to the first and second wavelengths output from the subject, wherein execution of code stored in the tangible, non-transitory computer-readable recording medium by one or more processors of a computer system causes the one or more processors to carry out:

• collecting the PPG signal corresponding to the first and second wavelengths for a predetermined unit period of time, the collected PPG signal including “n” pulse data for each of the first and second wavelengths, the “n” pulse data representing a group of n pulses in the PPG signal corresponding to the first wavelength and a group of n pulses in the PPG signal corresponding to the second wavelength, n being a positive integer larger than 1;
• calculating a ratio between a maximum intensity value and a minimum intensity value for each pulse of the “n” pulse data for each of the first and second wavelengths, and obtaining “n” first ratio values corresponding to the n pulses of the first wavelength and “n” second ratio values corresponding to the n pulses of the second wavelength;
• calculating third ratio values between “n” first ratio values and respective “n” second ratio values;
• calculating an average of “n” parameters, the “n” parameters being the third ratio values;
• among the “n” parameters, determining a number “m” of parameter values, deviations from the average are greater than a predetermined standard deviation, wherein when the first and second wavelengths correspond to an isosbestic point, the predetermined standard deviation is set to ±3.5% through ±4.5%;
• comparing a ratio m/n with a predetermined removal reference value to determine whether the “n” pulse data is valid;
• and
• replacing invalid “n” pulse data with new “n” pulse data, the new “n” pulse data being new pulse data in a newly collected PPG signal.

An apparatus for removing abnormal data in a blood component analysis system using spectroscopy to estimate a concentration of a blood component by analyzing a photo-plethysmographic (PPG) signal obtained by radiating light of first and second wavelengths reacting to the blood component on a subject and detecting light corresponding to the first and second wavelengths output from the subject, the apparatus comprising:

• a signal processor programmed to:
• extract the (PPG) signal corresponding to the first and second wavelengths reacting to a particular blood component from an electrical signal output in response to the detected light, the extracted PPG signal including “n” pulse data for each of the first and second wavelengths, the “n” pulse data representing a group of n pulses in the PPG signal corresponding to the first wavelength and a group of n pulses in the PPG signal corresponding to the second wavelength, n being a positive integer larger than 1,
• calculate a ratio between a maximum intensity value and a minimum intensity value for each pulse of the “n” pulse data of each of the first and second wavelengths, and obtain “n” first ratio values corresponding to the n pulses of the first wavelength and “n” second ratio values corresponding to the n pulses of the second wavelength,
• calculate third ratio values between the “n” first ratio values and respective “n” second ratio values, the third ratio values defining “n” parameter values with respect to the “n” pulse data included in the collected PPG signal,
• calculate an average of the “n” parameter values,
• among the “n” parameter values, to determine a number “m” of parameter values whose deviations from the average are greater than a predetermined standard deviation, wherein when the first and second wavelengths correspond to an isosbestic point, the predetermined standard deviation is set to ±3.5% through ±4.5%,
• compare m/n with a predetermined removal reference value to determine whether the “n” pulse data is valid, and
• replace invalid “n” pulse data with new “n” pulse data, the new “n” pulse data being new pulse data in a newly collected PPG signal.