Method, arrangement, sensor, and computer program product for non-invasively measuring hemoglobin concentrations in blood

An arrangement for non-invasively measuring hemoglobin concentrations in blood of a subject, the arrangement comprising:

• a pulse oximeter including at least one sensor having an emitter and a detector operable to obtain in vivo measurement signals of at least three wavelengths from the subject;
• a control unit including a memory device including a stored pre-determined first relationship between a first variable indicative of total hemoglobin concentration and an intermediate variable and a second relationship between the intermediate variable and a set of variables that includes second variables indicative of light transmission through tissue and third variables indicative of concentration percentages of different hemoglobin species, wherein the pre-determined first relationship is determined based on blood samples from at least other subject and the intermediate variable represents a product of absorption coefficient μa per unit and reduced scattering coefficient μs′ per unit volume;
• a first calculation unit configured to determine, based on the in-vivo measurement signals obtained from the subject, in-vivo values for the second and third variables;
• a second calculation unit configured to solve the first variable based on the in-vivo values of the second and third variables and the stored first and second relationships;
• and
• a display unit to display the hemoglobin concentrations.

A non-transitory computer-readable medium for use with a computer processor for non-invasively measuring hemoglobin concentrations in blood of a subject, the non-transitory computer-readable medium comprising:

• a first program product portion including a pre-determined first relationship determined based on blood samples from at least one other subject, the pre-determined first relationship representing a relationship between a first variable indicative of total hemoglobin concentration and an intermediate variable and a second relationship between the intermediate variable and a set of variables that includes second variables indicative of light transmission through tissue and third variables indicative of concentration percentages of different hemoglobin species, wherein the intermediate variable represents a product of absorption coefficient μa per unit and reduced scattering coefficient μs′ per unit volume;
• a second program product portion adapted to determine, based on in-vivo measurement signals obtained from a sensor having an emitter and a detector performing measurements of at least three wavelengths configured to be positioned on the subject, in-vivo values for the second and third variables;
• and
• a third program product portion adapted to solve the first variable based on the in-vivo values of the second and third variables and the first and second relationships.