Medicine

Measuring slow blood flow

Print edition : January 10, 2014

A new laser-based scheme allows the visualisation of blood flowing at very low speeds. Photo: Physical Review Letters

THE measurement of blood flow in human tissues is important for the diagnosis and assessment of many diseases. Current ultrasound techniques use the Doppler shift of the frequency of sound waves to measure the motion of blood cells. But the effect is undetectable for blood moving slower than about 10 millimetres per second. Now, researchers in the U.S. have demonstrated an ultrasound-based technique that can measure speeds as low as a quarter of a millimetre per second. The scheme uses laser pulses to track the sound waves generated by locally heating the blood with ultrasound.

The method may find use in biomedical applications ranging from functional brain imaging to the detection of cancer and atherosclerotic plaques. The work of Lidai Wang and others was recently published in the journal Physical Review Letters.

A letter from the Editor


Dear reader,

The COVID-19-induced lockdown and the absolute necessity for human beings to maintain a physical distance from one another in order to contain the pandemic has changed our lives in unimaginable ways. The print medium all over the world is no exception.

As the distribution of printed copies is unlikely to resume any time soon, Frontline will come to you only through the digital platform until the return of normality. The resources needed to keep up the good work that Frontline has been doing for the past 35 years and more are immense. It is a long journey indeed. Readers who have been part of this journey are our source of strength.

Subscribing to the online edition, I am confident, will make it mutually beneficial.

Sincerely,

R. Vijaya Sankar

Editor, Frontline

Support Quality Journalism
This article is closed for comments.
Please Email the Editor