title: Electro-optical plethysmography for non-invasive estimation of hemoglobin concentration.
abstract: Novel sensors and instrumentation are currently being investigated with the intended application of determining the concentration of hemoglobin and other optically absorbing compounds in blood using non-invasive methods. In order to measure concentration, the mass or amount of a compound must be known in addition to the volume of liquid. In principle, it may be possible to estimate hemoglobin concentration from a change in optical absorbance occurring over the cardiac cycle divided by a corresponding change in measured blood volume during the cycle measured from peripheral tissue, e.g. the finger or ear. Electrical and optical sensors were evaluated in vitro using a tissue phantom and an absorbing liquid medium. The effect of changes in optical absorption and pulse pressure on the capacitance and optical absorbance were studied.
authors.affiliation: School of Engineering and Mathematical Sciences, City University London, UK. Justin.phillips.1@city.ac.uk
authors.forename: Justin P
authors.initials: JP
authors.lastname: Phillips
authors.forename: Michelle
authors.initials: M
authors.lastname: Hickey
authors.forename: Panayiotis A
authors.initials: PA
authors.lastname: Kyriacou
mesh_terms: D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D010991:Plethysmography / Q000379:methods*
chemical_list: D006454:Hemoglobins