This is a single center, open label, prospective, randomized, controlled study in patients with non- revascularizable moderate or severe lower extremity Peripheral Arterial Disease (PAD) receiving autologous stem cells therapy (minimally manipulated). This study will enroll a maximum of 10 subjects in this study. The patients will be divided into two groups. One group will receive Adipose Derived Stem Cells (ADSCs) alone and the other group will receive low frequency ultrasound before the addition of ADSCs. The randomization will be 1:1. If the results of this pilot study are not clearly different, there will be a need for a phase II study to support the results.