The vascular laboratory provides objective diagnostic information on patients with vascular disease. The tests evaluate the presence, location and physiological extent of peripheral arterial, venous, and cerebrovascular disease. A complete exam takes only one hour. Echoes returning from moving red blood cells produce audible signals of arterial or venous flow. Spectrum analysis visually displays the doppler signal, quantifying blood velocities and disturbances.
Diodes send near infrared light into the superficial tissues.
Thsi light is absorbed by the red blood cells and cutaneous blood flow is recorded. Photoplethysmography is used to evaluate digital and penile blood flow and pressures, and in venous reflux testing. The limb segment or digit is encircled with a fine elastic tube filled with a mercury-like substance. The tube is connected to a circuit that measures electrical resistance thereby detecting changes in the length of the guage. Strain guage plethysmography is used to determine venous obstruction by measuring filling and emptying abilities of the limb.