Evaluation of Lower Extremity Tissue Perfusion With Polarized Laser Light

An objective assessment of blood supply and oxygen delivery to the damaged tissue in patients with diabetic ulcer is very problematic with various currently accepted auxiliary examinations. These tests include measuring blood pressure ratio between the ankle or toes arm (ABI \ TBI), Sonar Doppler examination of the lower limb arteries, and percutaneous tissue oxygen tension examination (TcPO2). Each of these tests, along with the obvious advantages esprit ability to assess a non-invasive blood as number of disadvantages.

As the blood supply to the tissue is the most important healing of the tissue regardless of the type of intervention chosen (conservative treatment includes systemic antibiotics or surgical debridement), there is clear necessity for a non-invasive test with high reliably assessing tissue perfusion in patients with diabetic ulcers.

Recently, a new a method for assessing multiple features in vital tissues using polarised laser light was introduced. The technique is based on tracking temporal changes of reflected secondary speckles produced in the skin when being illuminated by a laser beam. Change in skin's temporal vibration profile is generated by time varied oxygen concentration caused these temporal changes. This technology of nanometer motion sensing allows, according to studies already carried out, monitoring parameters such as blood pressure, pulse rate and heart rhythm, glucose concentration in the blood substances and alcohol, oxygen saturation and intraocular pressure.

In this study the investigators will examine, non-invasively, the tissue around the lower limb ulcers of 30 diabetic patients, beginning with the TcPO2 examination followed by the polarised laser light and complementary metal-oxide semiconductor (CMOS) camera examination, and analysing the data in order to determine the ability of the latter method for assessing the tissue oxygen pressure.