A Study to Evaluate Microvessel Ultrasound Imaging of Wound Healing in Patients With Chronic Ulcers

Inclusion Criteria: * Chronic wound in the course of diabetic foot ulcers and/or lower extremity venous ulcers with duration of at least 6 weeks and the wound surface not less than 2 sq. cm and not greater than 15 sq. cm, without evidence of active infection of the wound at the time of qualification to participate in the study * Meets criteria for stalled chronic wound defined as less than 50% reduction in wound size after 30 days of standard of care management. * For chronic venous ulcers, ultrasound demonstrates venous reflux \>0.5 seconds * Satisfactory blood glucose control - fasting not more than 110 mg%, HbA1c \<6.5% * Satisfactory blood supply to the wound verified by the measurement of the oxygen level of the foot tissue (TCPO2 \> 30mmHg) in patients with neuropathic etiology of diabetic foot syndrome * In the case of the patients with the wounds of ischemic component, the condition for qualification is a clinical improvement of the limb's blood supply as a result of the revascularization procedure documented by ultrasound. * Ankle-brachial index (ABI) ≥ 0.8 Exclusion Criteria: * Acute wound with duration less than 6 weeks * Evidence of active infection or on antibiotics * Smoker * For chronic venous ulcers, ultrasound demonstrates venous reflux \<0.5 seconds * Unsatisfactory blood glucose control - fasting more than 110 mg%, HbA1c \<6.5% * Poor blood supply to the wound verified by the measurement of the oxygen level of the foot tissue (TCPO2 \< 30mmHg) in patients with neuropathic etiology of diabetic foot syndrome * Ankle-brachial index (ABI) \< 0. * Pregnancy * Known allergy to lidocaine