Abstract: A method for generating microbubbles may include providing a syringe having a barrel defining an interior volume, a plunger, a tip and a check valve assembly. The check valve assembly may have an inlet port; a check valve that is configured to open when the plunger is drawn back by a user; and a nozzle in fluid communication with the interior volume and, when the check valve is open, in fluid communication with the inlet port. The method may include drawing liquid into the interior volume; removing a seal from the inlet port and drawing gas adjacent the inlet ports into the interior volume to form microbubbles in the liquid already drawn in; coupling the tip to an intravenous line associated with a patient undergoing a bubble study; and depressing the plunger to force the liquid and the formed microbubbles into the intravenous line.

Abstract: A method may include intravenously directing first bubbles into a patient's venous circulatory system and to a right side of the patient's heart. The first bubbles may have sizes that fall within a first range. The method may further include monitoring the patient's heart, with ultrasound imaging, to detect presence of the first bubbles on a left side of the patient's heart. Upon detecting the first bubbles on the left side of the patient's heart, the method may further include intravenously directing second bubbles into the patient's venous circulatory system and to the right side of the patient's heart. The second bubbles may have sizes that fall within a second range that is different than the first range. Upon detecting the second bubbles on the left side of the patient's heart, the method may further include initiating treatment to minimize risk of stroke in the patient.

Abstract: A method may include producing, in a solution, microbubbles of nitric oxide having a targeted size; and directing the solution to a right side of a patient's heart, such that the microbubbles are directed to the patient's pulmonary arteries prior to being circulated through the patient's body. The solution may include saline or dextrose. Directing the solution to the right side of the patient's heart may include delivering the solution via a catheter, during a right-heart catheterization procedure. Directing the solution to the right side of the patient's heart may include injecting the solution into a median cubital vein of the patient. Directing the solution to the right side of the patient's heart comprises injecting the solution into an internal jugular vein, an external jugular vein or a femoral vein of the patient. The targeted size may correspond to a diameter of a specific branch of the patient's pulmonary arteries.

Abstract: A method may include intravenously directing first bubbles into a patient's venous circulatory system and to a right side of the patient's heart. The first bubbles may have sizes that fall within a first range. The method may further include monitoring the patient's heart, with ultrasound imaging, to detect presence of the first bubbles on a left side of the patient's heart. Upon detecting the first bubbles on the left side of the patient's heart, the method may further include intravenously directing second bubbles into the patient's venous circulatory system and to the right side of the patient's heart. The second bubbles may have sizes that fall within a second range that is different than the first range. Upon detecting the second bubbles on the left side of the patient's heart, the method may further include initiating treatment to minimize risk of stroke in the patient.

Abstract: A method for generating microbubbles may include providing a syringe having a barrel defining an interior volume, a plunger, a tip and a check valve assembly. The check valve assembly may have an inlet port; a check valve that is configured to open when the plunger is drawn back by a user; and a nozzle in fluid communication with the interior volume and, when the check valve is open, in fluid communication with the inlet port. The method may include drawing liquid into the interior volume; removing a seal from the inlet port and drawing gas adjacent the inlet ports into the interior volume to form microbubbles in the liquid already drawn in; coupling the tip to an intravenous line associated with a patient undergoing a bubble study; and depressing the plunger to force the liquid and the formed microbubbles into the intravenous line.