Fast Camera Shows Even Small Variations In Blood Circulation

Compared to an earlier version, the new optical perfusion camera (TOPCam) from Twente, the Netherlands, is a significant improvement with regard to speed, so that even small variations in blood circulation are immediately visible. The camera is now ready for clinical application. Researchers of the Institute for Biomedical Technology (BMTI) of the University of Twente are publishing an article on the camera in the March number of Optics Express.

After earlier successful tests at the Martini Hospital in Groningen, the Netherlands, the researchers have made a number of significant improvements to the camera. The speed of the earlier version was commended by doctors and nurses, but real-time images of variations in the blood circulation were not yet possible. They are now, though, according to researcher Wiendelt Steenbergen: “We can now see rapid variations in blood circulation, too, for example when the circulation gets going again after occlusion of an arm or after a transplant.” The measured reaction gives an immediate impression of the condition of the vascular bed.

The researchers were able to reach these high speeds by using a broad laser beam to simultaneously illuminate the entire area of skin in question. Images are made of the tissue with a high-speed camera. Laser light that is scattered by moving red blood cells gives variation in the clarity of the pixels as a result of the Doppler Effect. Up till now it had been a problem transferring all the data to the computer quickly enough, but real time images are now enabled by making better use of the camera memory.

Now that the newest modifications have been made, the camera is ready for clinical application, Steenbergen says. The TOPCam is also suitable for other applications such as the assessment of blood circulation in diabetics. This research, which was carried out by the BMTI, was financed by the Technology Foundation (STW).