The objective of the clinical trial is to gather evidence on the safety, performance and clinical efficacy Vibrato Sleeve TUS in people with peripheral artery disease (PAD).

Subjects will be randomized to a test or control group and will receive an active or sham Vibrato Sleeve respectively.

Those randomized to the control arm will undergo therapy sessions with a sham Vibrato Sleeve device and two months of follow-up. Upon completion of the 2-month follow-up visit, subjects will be informed of their randomization assignment. Subjects in the sham arm will be allowed to crossover to a treatment regimen that uses an active Vibrato Sleeve device and will follow the same visit schedule as the active test group.

Inclusion Criteria:

1. Age ≥22.
2. Diagnosis of infrapopliteal PAD.
3. Rutherford class 4 or 5 as determined by the investigator.
4. Toe Brachial Index (TBI) ≤ 0.6 OR Toe Blood Pressure ≤ 50 mmHg.

Exclusion Criteria:

1. Prior stenting in posterior tibial, anterior tibial or peroneal artery.
2. Re-vascularization procedure within 25 days prior to enrollment in the study. (Note: Patients who had re-vascularization procedure earlier than 25 days prior to enrollment are eligible for enrollment if they meet other criteria).
3. Ulcers, cellulitis, or skin breakdown in treatment areas (posterior calf).
4. History or diagnosis of severe chronic venous insufficiency or mixed arterio-venous disease.
5. Acute limb ischemia within 30 days prior to treatment.
6. History or diagnosis of deep venous thrombosis below the knee in treatment leg.
7. Uncontrolled diabetes defined as HbA1c greater than 10%.
8. Ongoing hyperbaric oxygen treatment (HBOT)
9. Any conditions that, in the opinion of the investigator, may render the patient unable to complete the study or lead to difficulties for patient compliance with study requirements, or could confound study data.

9. Patient's enrollment in another investigational study that has not completed the required primary endpoint follow-up period (Note: Patients involved in a long-term surveillance phase of another study are eligible for enrollment in this study).

Data summaries, group outcomes, and study conclusions will be shared with other researchers. Individual participant data will not be shared.

Clinicians and subjects in both the active and sham group will be blinded to the randomized treatment assignments until 2-month follow-up visit. The sham and active devices will appear the same and appear to be utilized in the same manner. Only the Vibrato Medical person controlling the treatment device will be aware of the respective randomization for each subject. The second phase of this study, crossing over from sham to active treatment will not be concealed.