Pilot Clinical Trial of Ultrasound Guided Aortic Compression for Arresting Abdominal Aortic Blood Flow in Healthy Volunteers. This Isn't Device Feasibility, But Rather the Feasibility of a Clinical Maneuver; Specifically, Evaluating Whether the Technique Can Achieve the Anticipated Out

Feasibility Study of Ultrasound Guided Aortic Compression for Arresting Abdominal Aortic Blood Flow in Healthy Volunteers

As point-of-care ultrasound (POCUS) is becoming more available in the prehospital setting, it can be potentially used for more accurate and directed pressure application, thanks to its ability to image the artery and the underlying bony surface. The investigators therefore aim to conduct a feasibility study on healthy volunteers, to test the efficacy and tolerability of external abdominal compression using an ultrasound probe to obstruct blood flow in the abdominal aorta.

The aim of the study is to determine whether ultrasound-guided abdominal aortic compression is feasible as a method to stop distal blood flow.

Before the compression attempt, a research team member will use the first ultrasound device with a linear probe to locate the common femoral artery and measure the blood flow.

A second ultrasound device will be used to perform abdominal aortic pressure under vision. A curved probe will be placed on the upper abdomen, above the umbilicus, in the midline position and transverse orientation. The operator will have up to 2 minutes to obtain the desired sonographic view that allows for the compression to begin, with the middle of the probe, the abdominal aorta and the vertebra along the same line. Once the view is obtained, as declared by the operator and confirmed by a member of the study team, time required to obtain this view will be recorded, and recording of the common femoral blood flow will begin (for baseline) for 10 seconds, followed by 30 seconds of compression attempt (of which the compressing ultrasound view will also be recorded synchronously).the doppler graph will later be analyzed to determine the listed outcomes:

1. Success in aortic occlusion (binary).
2. Time to first achievement of aortic occlusion (seconds).
3. Percent of time of the test time with successful aortic occlusion (%).
4. Cumulativeflow reduction during the 30 seconds compression (%). At the end of the experiment, the participant will be requested to rate their level of discomfort between 0 and 10 (NRS - Numerical Rating Score)

The primary outcome will be success in achieving blood flow occlusion by compressing the abdominal aorta against lumbar vertebra as measured by no distal blood flow in the femoral artery, for any period within the 30 seconds of intervention.

Secondary outcomes will be:

1. Cumulative flow time in the femoral artery (failure of occlusion) as a percentage of the 30 seconds attempt time
2. Time required for achievement of full occlusion.
3. Time required to obtain the desired sonographic view.
4. Particiapant discomfort score (NRS).

Inclusion Criteria:

• Age 18-40 years.
• Informed consent.

Exclusion Criteria:

• Any known abdominal or vascular pathology.
• Any known peripheral neuropathy.
• BMI>30.
• Sensitivity to ultrasonic gel.
• Tendency for syncope/ pre-syncope during blood-drawing, intravenous cannulation, etc.
• Personnel actively serving in the IDF.
• Pregnant/ possibly pregnant individuals.
• People lacking the ability to give informed consent.
• All of the above will be based on subjects' self-reporting. Subjects will be encouraged to consult with their physician.