Robert "Robin" Sanno Fåhræus ( ; 15 October 1888 – 18 September 1968) was a Swedish medical researcher noted for his contributions to

hemorheology Hemorheology, also spelled haemorheology (''haemo'' from Greek ‘αἷμα, ''haima'' 'blood'; and ''rheology'', from Greek ῥέω ''rhéō'', ' flow' and -λoγία, ''-logia'' 'study of'), or blood rheology, is the study of flow properties o ...

Biography

Fåhræus was the son of art historian and actress Olga Björkegren. He commenced studies at

Karolinska Institute The Karolinska Institute (KI; ; sometimes known as the (Royal) Caroline Institute in English) is a research-led medical university in Solna within the Stockholm urban area of Sweden and one of the foremost medical research institutes globally ...

in 1908, where he received his medical license in 1922. Before that, in 1921, he had completed his research doctorate with the title ''The suspension-stability of the blood''. He became associate professor of experimental

pathology Pathology is the study of disease. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in the context of modern medical treatme ...

at the Karolinska Institute in 1922. He was professor of pathology at

Uppsala University Uppsala University (UU) () is a public university, public research university in Uppsala, Sweden. Founded in 1477, it is the List of universities in Sweden, oldest university in Sweden and the Nordic countries still in operation. Initially fou ...

from 1928 to 1947, and professor of general pathology and pathological anatomy in Uppsala from 1947 to 1955, after his previous chair had been split in two. Fåhræus became a member of the

Royal Swedish Academy of Sciences The Royal Swedish Academy of Sciences () is one of the Swedish Royal Academies, royal academies of Sweden. Founded on 2 June 1739, it is an independent, non-governmental scientific organization that takes special responsibility for promoting nat ...

in 1935. In 1966, the International Society of Hemorheology awarded him their first Poiseuille medal, the Society's highest award.

Research

While studying at the Karolinska Institute he conducted research on

eclampsia Eclampsia is the onset of seizures (convulsions) in a pregnant woman with pre-eclampsia. Pre-eclampsia is a hypertensive disorder of pregnancy that presents with three main features: new onset of high blood pressure, large amounts of proteinuria ...

and observed that blood samples from pregnant women easily could be distinguished from other blood samples because the

red blood cell Red blood cells (RBCs), referred to as erythrocytes (, with -''cyte'' translated as 'cell' in modern usage) in academia and medical publishing, also known as red cells, erythroid cells, and rarely haematids, are the most common type of blood cel ...

s descended more quickly in the test tubes, leaving a thick layer of

blood plasma Blood plasma is a light Amber (color), amber-colored liquid component of blood in which blood cells are absent, but which contains Blood protein, proteins and other constituents of whole blood in Suspension (chemistry), suspension. It makes up ...

on top. This phenomenon is the

erythrocyte sedimentation rate The erythrocyte sedimentation rate (ESR or sed rate) is the rate at which red blood cells in anticoagulated whole blood descend in a standardized tube over a period of one hour. It is a common hematology test, and is a non-specific measure of in ...

, which can be used as a diagnostic tool. After Fåhræus had received his position at the Karolinska Institute in 1922, he sought contact with professor

Theodor Svedberg Theodor Svedberg (30 August 1884 – 25 February 1971; also known as The Svedberg) was a Swedish chemist and Nobel laureate for his research on colloids and proteins using the ultracentrifuge. Svedberg was active at Uppsala University from the ...

in Uppsala and suggested that the recently built

ultracentrifuge An ultracentrifuge is a centrifuge optimized for spinning a rotor at very high speeds, capable of generating acceleration as high as (approx. ). There are two kinds of ultracentrifuges, the preparative and the analytical ultracentrifuge. Both cla ...

should be used to determine the

molecular mass The molecular mass () is the mass of a given molecule, often expressed in units of daltons (Da). Different molecules of the same compound may have different molecular masses because they contain different isotopes of an element. The derived quan ...

hemoglobin Hemoglobin (haemoglobin, Hb or Hgb) is a protein containing iron that facilitates the transportation of oxygen in red blood cells. Almost all vertebrates contain hemoglobin, with the sole exception of the fish family Channichthyidae. Hemoglobin ...

. Svedberg and Fåhræus published the result in 1926, the same year Svedberg received the

Nobel Prize in Chemistry The Nobel Prize in Chemistry () is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, awarded for outst ...

. In Uppsala from 1928, Fåhræus started to study the flow of blood in thin blood vessels, which led to the discovery of two effects named after him. In 1929 he described the Fåhræus effect, a decrease in the average concentration of red blood cells when blood flows in a tube of smaller diameter. In 1931 he and co-worker Torsten Lindqvist described the Fåhræus–Lindqvist effect, the change of the

viscosity Viscosity is a measure of a fluid's rate-dependent drag (physics), resistance to a change in shape or to movement of its neighboring portions relative to one another. For liquids, it corresponds to the informal concept of ''thickness''; for e ...

of blood with the diameter of the tube it travels through.

References

{{DEFAULTSORT:Fåhraeus, Robin Academic staff of Uppsala University Karolinska Institute alumni Swedish pathologists Members of the Royal Swedish Academy of Sciences Robin Fåhræus Hematologists 20th-century Swedish physicians 1888 births 1968 deaths Members of the Royal Society of Sciences in Uppsala