Method for non-evasively determining an endothelial function and a device for carrying out said method

An apparatus for noninvasive assessment of endothelial function comprising a double-channeled sensor unit, capable of detecting pulse wave signals from peripheral arteries, a pneumatic unit capable of creating gradually increasing pressure in a pressure generating cuff, a pressure sensor configured to detect a blood pressure of a patient;

• and an electronic block configured to perform at least the following steps:
• a. lowering a transmural pressure in an artery in an extremity by means of a pressure generating cuff;
• b. measuring, via a monitoring channel, an amplitude of a plethysmographic signal at various transmural pressures generated in step (a);
• c. determining a pressure in the pressure generating cuff at which the amplitude of the plethysmographic signal is maximal;
• d. lowering the pressure in the pressure generating cuff to 50% of the pressure at which said maximal amplitude occurs;
• e. when the pressure in the pressure generating cuff is 50% of the pressure at which said maximal amplitude occurs, running an occlusion test wherein running an occlusion test comprises generating a pressure in the pressure generating cuff on an observed region of the extremity which exceeds a measured systolic pressure by at least 50 mmHg for at least 5 minutes;
• f. lowering the pressure in the pressure generating cuff to zero;
• g. measuring an amplitude of the plethysmographic signal for at least 3 minutes and simultaneously measuring, via a reference channel, an amplitude of a plethysmographic signal detected from an artery in a second extremity where the occlusion test has not been performed;
• and
• h. using amplitudal and timely analyses to compare data collected through the reference and monitoring channels;
• wherein the double-channeled sensor unit is connected to the electronic block, which is in turn linked through an outlet to the pneumatic unit.