Perfusion in burn injuries rapidly determined by using improved laser-Doppler technology

Using the perfusion image made by a laser and an ultra fast camera, doctors will be able to determine whether a burn needs surgery. The new measuring device, developed under supervision of dr. Wiendelt Steenbergen of the Biophysical Engineering group, has been successfully tested at the hospital Martini Ziekenhuis in Groningen.

Tests in hospital show that the system is perfectly capable of measuring differences in perfusion in burn wounds; patients and medical staff are positive about the high speed of the system and the quality of the images.

A burn that shows good perfusion, has a better chance of healing by itself: no surgery is needed. In many cases, the visual inspection is not sufficient to take a decision on the necessity of surgery. This can lead to unnecessary surgery or, on the other hand, to unwanted delays when surgery is the best option. Compared to current perfusion measurements, the new technique is much faster. Scanning techniques take minutes of time for some square centimeters of skin, during which time the patient is not allowed to move. The new technique will be capable of imaging an entire surface of ten by ten centimeter in a fraction of a second.

Doppler effect
In order to reach this high speed, the entire surface is lit at once using a wide laser beam. A high speed camera, capable of taking 27000 shots per second, takes images of the tissue. Whenever laser light is scattered by moving rood blood cells, this is visible in the intensity of the pixels; due to the Doppler effect, a colour shift will be visible. From the resulting ‘movie’ of the tissue, a perfusion image can be made.

Apart from this promising application in determing perfusion in burn injuries, Wiendelt Steenbergen predicts other applications, for example in evaluating the uptake of medication through the skin, or in testing allergic reactions. In evaluating diabetic micro circulation problems, the new technique could be an attractively fast alternative to current approaches as well.