Patent ID: 8882693
Filing Date: 2014-11-11
Classification: A61M,F16K

Abstract:
1. A method for providing extracorporeal circulation to a patient comprising the steps of: a) priming a heart-lung machine with a priming liquid in a priming mode; b) switching the heart-lung machine from the priming mode to an operational mode; c) connecting a venous blood inlet on the heart-lung machine to a vein in the patient and connecting an arterial blood outlet from the heart lung machine to an artery in the patient to form a closed extracorporeal blood circulation in fluid contact with the patient circulatory system; d) causing the heart-lung machine to operate in said operational mode to take venous blood from the patient, oxygenate the venous blood, and return oxygenated blood through an arterial line and to the patient; and wherein said heart-lung machine comprises: a blood reservoir separated into a blood-containing space and an air-containing space by a membrane that is permeable to blood but not to air bubbles, said blood reservoir configured to receive blood from said venous connection; a centrifugal pump having a central inlet and a tangential outlet and configured to draw blood from said blood reservoir and pump the blood into an oxygenator; an arterial filter located on the arterial line downstream of said oxygenator; a bubble detector located on the arterial line downstream of said arterial filter said bubble detector being constructed to emit a bubble detection signal when a bubble is detected by the bubble detector; a quick action clamp disposed on the arterial line downstream of the bubble detector said quick action clamp being spring biased to a closed position, said quick action clamp further comprising a latch which holds the clamp in an open position against said spring bias; a bypass line connecting to said arterial line between the bubble detector and the quick action clamp and configured to transport blood from the arterial line to the blood reservoir; and a bypass clamp disposed on the bypass line; and a controller which receives bubble detection signals from the bubble detector and is programmed to respond to receipt of a bubble detection signal from the bubble detector by stopping the centrifugal pump, releasing the latch of the quick action clamp thereby allowing the spring bias to move the quick action clamp from the open position to the closed position, opening the bypass clamp and restarting the centrifugal pump, thereby diverting blood flow so that blood containing the detected bubble is diverted from the arterial line, through the bypass line and back into the blood reservoir; wherein: said heart-lung machine operation comprises the steps of: e) pumping blood received from the patient through the venous connection through a blood reservoir and an arterial line to an arterial connection; f) causing the bubble detector to monitor for air bubbles in the arterial line; g) allowing the controller to operate such that, when the bubble detector detects an air bubble, the latch of the quick action clamp is released causing the quick action clamp to close, the blood pump is stopped, the bypass clamp is opened and the blood pump is re-started so that the blood containing the detected air bubble flows from the arterial line, through the bypass line and back into the blood reservoir; h) extracting air from the air-containing space in the blood reservoir using an air extraction pump; and i) thereafter, further operating the controller such that the arterial clamp is opened and the bypass clamp is closed, thereby again causing blood to flow from the arterial line to the patient.