A control system controlling the blood flow rate in a blood supply system (1) in which a pump (18) transports blood from a reservoir (10) toward multiple outlets (30, 26, 26a) of which one or more outlets are openable to permit flow and closable to block flow, wherein the control system comprises a monitoring arrangement (22, 32, 32a) to determine the flow rate through a first outlet (30), and a controller responsive to the monitoring arrangement and controlling the pump (18) to maintain the flow rate through the first outlet (30) at a pre-determined level. This allows a flow rate through the first outlet to be maintained independently of any active blood diversions.

A system and methods are described for improving the management of ischemic cardiac tissue during acute coronary syndromes. The system combines a catheter-based sub-system which allows for simultaneous balloon dilation of a coronary artery and infusion of a carefully controlled perfusate during percutaneous coronary intervention. The system allows for modulation of levels of oxygen at the time of percutaneous intervention. In addition, catheters and systems are provided for administration of fluids with modified oxygen content during an intervention that incorporate upstream flow control members to compartmentalize the perfusion of the target coronary artery and the remainder of the heart.

A heater-cooler apparatus of an extracorporeal perfusion system comprises at least one fluid circuit (102, 104) providing a supply of a heat transfer fluid to the perfusion system, a cold storage unit (266), and a refrigeration unit (250) for charging the cold storage unit (266). The cold storage unit (266) comprises a chamber (312) containing a liquid that freezes at a temperature above that to which the heat transfer fluid is cooled by the refrigeration unit (250), and a passage through which the heat transfer fluid is conveyed, the passage extending through the chamber (312). This allows a more effective cold storage unit to be provided.

A cold and heat exchange system for a cardiac surgical operation with cardiac arrest, comprising: an ice water tank (15), a primary circulation water tank (11), and a secondary circulation water tank (16). Side walls of the primary circulation water tank (11) and the secondary circulation water tank (16) are each provided with an overflow orifice which is connected to the ice water tank (15) through a circulation pipe (14). A first roller pump (12) is mounted on a first hose (13). A second roller pump (18) is mounted on a second hose (17). The primary circulation water tank (11) is mounted on a first loop (5) and a second loop (6). The secondary circulation water tank (16) is mounted on a third loop (1).

A control system controlling the line pressure in a blood supply system (1) in which a pump (14) pumps blood from a reservoir (10) via a primary passage (18) toward a plurality of outlets (16, 26, 26a), wherein one or more outlets are openable to permit flow and closable to block flow, said control system comprises a monitoring arrangement to determine a line pressure in the primary passage, and a controller responsive to the monitoring arrangement and controlling the pump (14) to maintain the line pressure in the primary passage (18) above a pre-set level. The control system practically eliminates the risk of a momentary reduction in blood supply line pressure when an outlet is opened.

The method and system of the present invention detects cellular electrical activity and/or temperature continuously in real time to indicate the level of cellular arrest in the myocardial and conductive cells, allowing for the adjustment of cardioplegia, temperature, and/or increasing or decreasing the ratio of blood to electrolytes (cardioplegia) in order to eliminate or minimize myocardial ischemia that occurs when cellular arrest is not obtained or maintained during cardiac surgery. In a preferred embodiment of the present invention, a conductive wire and/or a thermistor are imbedded in or on the walls of a retrograde and/or other cannula to detect low amplitude electrical activity and/or temperature, respectively. In an alternate preferred embodiment of the present invention sensors for electrolyte, pO.sub.2, pCO.sub.2, or cardiac enzymes could also be added or used in replacement of other sensors.

A cardioplegic agent delivery system comprises a syringe pump for providing cardioplegic agent into a carrier fluid of a perfusion system, a flow sensor for sensing a flow of the carrier fluid, and an interlock responsive to the flow sensor. The interlock prevents operation of the syringe pump in the absence of carrier fluid flow sensed by the flow sensor. This provides increased safety in a cardioplegic agent delivery system.

A cold and heat exchange system for a cardiac surgical operation with cardiac arrest, comprising: an ice water tank (15), a primary circulation water tank (11), and a secondary circulation water tank (16). Side walls of the primary circulation water tank (11) and the secondary circulation water tank (16) are each provided with an overflow orifice which is connected to the ice water tank (15) through a circulation pipe (14). A first roller pump (12) is mounted on a first hose (13). A second roller pump (18) is mounted on a second hose (17). The primary circulation water tank (11) is mounted on a first loop (5) and a second loop (6). The secondary circulation water tank (16) is mounted on a third loop (1).

A method of controlling thermal transfer in a perfusion system heat exchanger of an extracorporeal fluid treatment device for conditioning an extracorporeal patient fluid for administration to a patient comprises a step of providing a perfusion system heat exchanger, wherein the perfusion system heat exchanger comprises a first fluid passage for a liquid heat transfer medium and a second fluid passage for the extracorporeal patient fluid to be temperature-controlled via exchange of thermal energy with the heat transfer medium, and a step of providing the heat transfer medium through the first fluid passage. The heat transfer medium comprises a component with anti-microbial properties, such as glycol. The provision of antimicrobial fluid reduces the risk of microbe contamination of the extracorporeal fluid, and hence the risk of clinical complications.

An extracorporeal blood heating and cooling system that is connectable to an oxygenator of a cardiopulmonary bypass system, the heating and cooling system comprising: a heater-cooler unit; a coolant flow circuit that is configured to pass coolant through the heater-cooler unit and the oxygenator; and a cardioplegia coolant circuit that is configured to pass coolant through the heater-cooler unit and a cardioplegia heat exchanger; wherein when the heating and cooling system is in a purging mode, the coolant flow circuit and the cardioplegia coolant circuit contain temperature-controlled coolant having a trisodium phosphate concentration of about 1-35 millimole/liter; wherein when the heating and cooling system is in a coolant mode, the coolant flow circuit and the cardioplegia coolant circuit contain temperature-controlled coolant having a trisodium phosphate concentration of about 1-10 millimole/liter; and wherein when the heating and cooling system is in the coolant mode or the purging mode, a first and second plurality of coolant conduits within the oxygenator and the cardioplegia heat exchanger are capable of maintaining a trisodium phosphate concentration ratio across the wall of such coolant conduits of at least 100:1, from the interior to the exterior of each coolant conduit. Methods of purging and operating such extracorporeal blood heating and cooling systems are also disclosed.