Ultrasound of the Spleen Utilizing Low-energy (Diagnostic Level) Insonification.

This is a three-cohort, randomized, double-blinded , sham-controlled, single-center, early feasibility research trial to determine whether organ-specific biologic effects on platelet activity and coagulation are achievable through selective ultrasound of the spleen utilizing low-energy (diagnostic-level) insonification. * Group 1: Focused insonification at center of the spleen. * Group 2: Prolonged duration insonification at center of the spleen * Group 3: Prolonged duration insonification across the spleen. Participants will receive 30 minutes of sham stimulation in the randomized group that is assigned to them, followed by active stimulation within the same group. Blood biomarkers (local and systemic) will be measured before and at several timepoints after stimulation to measure the molecular and cellular effects of the device