Cardioplegia administration system and method

A cardioplegia administration system for mixing and administering cardioplegia and/or blood to a patient's heart during cardiopulmonary bypass surgery, the system comprising:

• a tubing set comprising:
• a cardioplegia supply tube having upstream and downstream ends, the upstream end of the cardioplegia supply tube being adapted to connect the cardioplegia supply tube to a source of cardioplegia medication;
• a blood supply tube having upstream and downstream ends, the upstream end of the blood supply tube being adapted to connect the blood supply tube to a source of blood or blood substitute;
• and
• a cardioplegia administration tube connected to the downstream ends of the cardioplegia and blood supply tubes, the cardioplegia administration tube being adapted to supply cardioplegia solution to the patient's heart:
• (b) a positive displacement pump for pumping fluid through the cardioplegia administration tube;
• and
• (c) mixing system for controlling the ratio of cardioplegia medication and blood or blood substitute in the cardioplegia solution in the cardioplegia administration tube, the mixing system comprising:
• pinch valves for alternately-continually pinching the cardioplegia and blood supply tubes to close and open the cardioplegia and blood supply tubes such that only one of the cardioplegia and blood supply tubes is open at a time;
• and
• control means for controlling the intervals during which the pinch valves are open with respect to each of the cardioplegia and blood supply tubes to control the ratio of the cardioplegia and blood or blood substitute administered through the cardioplegia administration tube;
• the system further comprising a recirculation tube having upstream and downstream ends in fluid communication with the cardioplegia administration tube on opposite sides of the positive displacement pump, and a non-invasive overpressure valve acting on the recirculation tube which is normally closed to close the recirculation tube to fluid flow but which is openable in response to an increase in pressure in the cardioplegia administration tube for allowing recirculation of fluid through the recirculation tube, the control means including means operably responsive to the overpressure valve, for actuating the pinch valves to close both of the cardioplegia and blood supply tubes when the overpressure valve is opened.

A cardioplegia administration system for mixing and administering cardioplegia and/or blood to a patient's heart during cardiopulmonary bypass surgery, the system comprising:

• (a) a tubing set comprising:
• a cardioplegia supply tube having upstream and downstream ends, the upstream end of the cardioplegia supply tube being adapted to connect the cardioplegia supply tube to a source of cardioplegia medication;
• a blood supply tube having upstream and downstream ends, the upstream end of the blood supply tube being adapted to connect the blood supply tube to a source of blood or blood substitute:
• and
• a cardioplegia administration tube connected to the downstream ends of the cardioplegia and blood supply tubes, the cardioplegia administration tube being adapted to supply cardioplegia solution to the patient's heart;
• (b) a positive displacement pump for pumping fluid through the cardioplegia administration tube:
• and
• (c) a mixing system for controlling the ratio of cardioplegia medication and blood or blood substitute in the cardioplegia solution in the cardioplegia administration tube, the mixing system comprising:
• pinch valves for alternately-continually pinching the cardioplegia and blood supply tubes to close and open the cardioplegia and blood supply tubes such that only one of the cardioplegia and blood supply tubes is open at a time;
• and
• control means for controlling the intervals during which the pinch valves are open with respect to each of the cardioplegia and blood supply tubes to control the ratio of the cardioplegia and blood or blood substitute administered through the cardioplegia administration tube;
• the system further comprising a recirculation tube having upstream and downstream ends in fluid communication with the cardioplegia administration tube on opposite sides of the positive displacement pump, and a recirculation valve acting on the recirculation tube which is normally closed to close the recirculation tube to fluid flow, but which is selectively openable to allow recirculation of fluid through the recirculation tube, the control means including means for actuating the pinch valves to close both of the cardioplegia and blood supply tubes when the recirculation valve is opened.

A mixing system for mixing two or more biological or medical fluids, the system comprising:

• (a) a tubing set comprising:
• a first supply tube having upstream and downstream ends, the upstream end of the first supply tube being adapted to connect the first supply tube to a source of a first biological or medical fluid;
• a second supply tube having upstream and downstream ends, the upstream end of the second supply tube being adapted to connect the second supply tube to a source of a second biological or medical fluid;
• and
• a mixing tube having an upstream end connected to the downstream ends of the first and second supply tubes, and a downstream end for supplying a mixed fluid comprising a preselected composition of the first and second fluids, the mixing tube having a lumen, in which the first and second fluids are mixed, and an exterior surface separated from the lumen by a tube wall;
• (b) a positive displacement pump in pumping engagement with the exterior surface of the mixing tube for pumping fluid through the mixing tube;
• and
• (c) a mixer for controlling the ratio of the first fluid and the second fluid in the mixed fluid, the mixer comprising:
• mixing valves for alternately-continually closing and opening the first and second supply tubes such that only one of the first and second supply tubes is open at a time;
• and
• a controller for controlling the intervals during which the mixing valves are open with respect to each of the first and second supply tubes to control the ratio of the first and second fluids in the mixed fluid supplied through the mixing tube;
• the mixing system further comprising a recirculation tube having upstream and downstream ends in fluid communication with the mixing tube on opposite sides of the positive displacement pump, and a recirculation valve along the recirculation tube which is normally closed to close the recirculation tube to fluid flow but which is selectively openable to allow recirculation of fluid through the recirculation tube.

The mixing system for mixing two or more biological or medical fluids, the system comprising:

• (a) a tubing set comprising:
• a first supply tube having upstream and downstream ends, the upstream end of the first supply tube being adapted to connect the first supply tube to a source of a first biological or medical fluid:
• a second supply tube having upstream and downstream ends, the upstream and of the second supply tube being adapted to connect the second supply tube to a source of a second biological or medical fluid;
• and
• a mixing tube having an upstream end connected to the downstream ends of the first and second supply tubes, and a downstream end for supplying a mixed fluid comprising a preselected composition of the first and second fluids, the mixing tube having a lumen, in which the first and second fluids are mixed, and an exterior surface separated from the lumen by a tube wall;
• (b) a positive displacement pump in pumping engagement with the exterior surface of the mixing tube for pumping fluid through the mixing tube;
• and
• (c) a mixer for controlling the ratio of the first fluid add the second fluid in the mixed fluid, the mixer comprising;
• pinch valves for alternately-continually pinching the first and second supply tubes to close and open the first and Second supply tubes such that only one of the first and second supply tubes is open at a time:
• and
• a controller for controlling the intervals during which the pinch valves are open with respect to each of the first and second supply tube to control the ratio of the first and second fluids in the mixed fluid supplied through the mixing tube;
• the mixing system further comprising a recirculation tube having upstream and downstream ends in fluid communication with the mixing tube on opposite sides of the positive displacement pump, and a non-invasive overpressure valve means acting on the recirculation tube which is normally closed to close the recirculation tube to fluid flow but which is openable in response to an increase in pressure in the mixing tube for allowing recirculation of fluid through the recirculation tube, the controller including means, operably responsive to the overpressure valve means, for actuating the pinch valves to close both of the first and second supply tubes when the overpressure valve means is opened.

A method of mixing and administering a cardioplegia solution comprising cardioplegia and/or blood to a patient's heart during cardiopulmonary bypass surgery, the method comprising:

• providing a tubing set comprising a cardioplegia supply tube having upstream and downstream ends, the upstream end of the cardioplegia supply tube being in fluid communication with a source of cardioplegia medication;
• a blood supply tube having upstream and downstream ends, the upstream end of the blood supply tube being in fluid communication with a source of blood or blood substitute;
• a cardioplegia administration tube connected to the downstream ends of the cardioplegia and blood supply tubes and being in fluid communication with the patient's heart;
• and a recirculation tube having upstream and downstream ends in fluid communication with the cardioplegia administration tube;
• mounting the cardioplegia administration tube in a positive displacement pump, with the upstream and downstream ends Of the recirculation tube on opposite sites of the positive displacement pump, for pumping fluid through the cardioplegia administration tube;
• mounting the cardioplegia and blood supply tubes in pinch valves;
• mounting the recirculation tube in a non-invasive overpressure valve such that the overpressure valve normally closes the recirculation tube to fluid flow but which is openable in response to an increase in pressure in the cardioplegia administration tube for allowing recirculation of fluid through the recirculation tube;
• alternately-continually pinching the cardioplegia and blood supply tubes with the pinch valves to close and open the cardioplegia and blood supply tubes such that only one of the cardioplegia and blood supply tubes is open at a time;
• controlling the intervals during which the pinch valves are open with respect to each of the cardioplegia and blood supply tubes to control the ratio of the cardioplegia medication and blood or blood substitute comprising the cardioplegia solution administered through the cardioplegia administration tube:
• and
• in the event that pressure in the cardioplegia administration tube increases to a predetermined pressure, opening the overpressure valve to allow recirculation of fluid through the recirculation tube.

A cardioplegia administration system for mixing and administering cardioplegia and/or blood to a patient's heart during cardiopulmonary bypass surgery, the system comprising:

• a replaceable tubing set comprising a cardioplegia supply tube, a blood supply tube, and a cardioplegia administration tube, the cardioplegia supply tube having upstream and downstream ends, the upstream end of the cardioplegia supply tube being adapted to connect the cardioplegia supply tube to a source of cardioplegia medication;
• and the blood supply tube having Upstream and downstream ends, the upstream end of the blood supply tube being adapted to connect the blood supply tube to a source of blood or blood substitute;
• and the cardioplegia administration tube being connected to the downstream ends of the cardioplegia and blood supply tubes, and adapted to supply cardioplegia solution to the patient's heart;
• at least portions of the cardioplegia supply tube and the blood supply tube being contained in a cassette adapted for mounting on a mixer:
• and
• a mixer for controlling the ratio of cardioplegia medication and blood or blood substitute in the cardioplegia solution in the cardioplegia administration tube, the mixer adapted to receive the cassette of the replaceable tubing set, and having pinch valves for alternately-continually pinching the portions of the cardioplegia and blood supply tubes in the cassette to close and open the cardioplegia and blood supply tubes such that on by one of the cardioplegia and blood supply tubes is open at a time;
• and control means for controlling the intervals during which the pinch valves are open with respect to each of the cardioplegia and blood supply tubes to control the ratio of the cardioplegia and blood or blood substitute administered through the cardioplegia administration tube;
• the system further comprising a positive displacement pump for pumping fluid through the cardioplegia administration tube, the replaceable tubing set further comprising a recirculation tube having upstream and downstream ends in fluid communication with the cardioplegia administration tube on opposite sides of the positive displacement pump, a portion of the recirculation tube being in the cassette;
• and wherein the mixer comprises a non-invasive overpressure valve that acts on the portion of the recirculation tube in the cassette, the overpressure valve being normally closed but being openable in response to an increase in pressure in the cardioplegia administration tube for allowing recirculation of fluid through the recirculation tube, the control means including means for actuating the pinch valves to close both of the cardioplegia and blood supply tubes when the overpressure valve is opened.

A mixing system for mixing two or more biological or medical fluids, the system comprising:

• a replaceable tubing set comprising:
• a first supply tube, a second supply tube, and a mixing tube, the first supply tube having upstream and downstream ends, the upstream end of the first supply tube being adapted to connect the first supply tube to a source of a first biological or medical fluid;
• the second supply tube having upstream and downstream ends, the .upstream end of the second supply tube being adapted to connect the second supply tube to a source of a second biological or medical fluid;
• and the mixing tube having an upstream end connected to the downstream ends of the first and second supply tubes, and a downstream end for supplying a mixed fluid comprising a preselected composition of the first and second fluids, the mixing tube having a lumen in which the first and second fluids are mixed, and an exterior surface separated from the lumen by a tube wall;
• at least portions of the first and second supply tubes being contained in a cassette that is adapted to be mounted on a mixer;
• and
• a mixer for controlling the ratio of the first fluid and the second fluid in the mixed fluid, the mixer adapted mount the cassette of the tubing set, the mixer having pinch values for alternately-continually pinching the portions of the first and second supply tubes in the cassette to close and open the first and second supply tubes such that only one of the first and second supply tubes is open at a time;
• and control means for controlling the intervals during which the pinch valves are open with respect to each of the first and second supply tubes to control the ratio of the first and second fluids in the mixed fluid supplied through the mixing tube;
• the tubing set further comprising a recirculation tube having upstream and downstream ends in fluid communication with the mixing tube, a portion of the recirculation tube being in the cassette, and wherein the mixer further comprises a non-invasive overpressure valve means acting on the portion of the recirculation tube in the cassette, the overpressure valve being normally closed to close the recirculation tube to fluid flow but which is openable in response to an increase in pressure in the mixing tube for allowing recirculation of fluid through the recirculation tube, the control means including means for actuating the pinch valves to close both of the first and second supply tubes when the overpressure valve is opened.