Cardioplegia delivery system

A cardioplegia system for delivering cardioplegic solution comprising blood and at least a second fluid to the heart through a cardioplegia delivery line during open heart surgery in cooperation with an extracorporeal blood circuit employing a heart/lung machine serving as a source for blood, and with a second source for said second fluid, comprising:

• (a) a conduit diverting a portion of the blood flow from the heart/lung machine to the cardioplegia delivery line;
• (b) a pump having a pump chamber with an inlet and an outlet, said pump having means for metering blood from the conduit into the pump chamber and combining it in an adjustable ratio with a second fluid metered by the pump from said second source into the pump chamber, and delivering the combined flow into the delivery line;
• and
• (c) control means for adjusting the ratio of blood and second fluid delivered by the pump and for adjusting the total volumetric rate of flow from the pump.

A clinical multi-fluid pumping system comprising:

• (a) a patient delivery line;
• (b) a first pump for pumping a first blood-containing fluid comprising a mixture of blood and a third fluid into the patient delivery line, said first pump being adapted to deliver said blood and third fluid in a variable ratio;
• (c) a second pump for delivering a second fluid into the delivery line downstream from the first pump at a flow rate less than 10% of the flow rate of the output from the first pump;
• and
• (d) control means for:
• adjusting the total volumetric rate of flow from the first pump;
• adjusting the ratio of blood to third fluid delivered by the first pump;
• and controlling the operation of the second pump so that the volumetric rate of flow of the second fluid is automatically maintained at a selected percentage of the flow rate from the first pump at all adjusted volumetric rates of flow from the first pump.

A cardioplegia system for delivering cardioplegic solution comprising at least first and second fluids to the heart through a cardioplegic delivery line during open heart surgery in cooperation with an extracorporeal blood circuit employing a heart/lung machine, comprising:

• (a) a cardioplegic delivery line;
• (b) a first pump for pumping a first fluid into the cardioplegic delivery line;
• (c) a second pump for delivering a second fluid adapted to inhibit the action of the heart into the delivery line downstream from the first pump at a flow rate less than 10% of the flow rate of the output from the first pump;
• and
• (d) control means for:
• adjusting the total volumetric rate of flow from the first pump;
• and controlling the operation of the second pump so that the volumetric rate of flow of the second fluid is automatically maintained at a selected percentage of the flow rate from the first pump at all adjusted volumetric rates of flow from the first pump by automatically resetting the volumetric rate of flow from the second pump at any time the volumetric rate of flow from the first pump is changed.

A cardioplegia system for delivering cardioplegic solution comprising blood and at least second and third fluids to the heart through a cardioplegic delivery line during open heart surgery in cooperation with an extracorporeal blood circuit employing a heart/lung machine, comprising:

• (a) a conduit diverting a portion of the blood flow from the heart/lung machine to the cardioplegia delivery line;
• (b) a heat exchanger for controlling fluid temperature in the cardioplegia delivery line;
• (c) a first pump for combining the blood from the conduit with the second fluid and delivering the combined flow into the delivery line leading to the heat exchanger;
• (d) a second pump for delivering the third fluid into the delivery line at a flow rate less than 5% of the flow rate of the combined output of the first pump;
• and
• (e) control means for adjusting the total volumetric rate of flow from the first pump, and for controlling the operation of the second pump so that the volumetric rate of flow of the third fluid is maintained at a selected percentage of the flow rate from the first pump.

A cardioplegia system for delivering cardioplegic solution comprising blood and at least second and third fluids to the heart through a cardioplegia delivery line during open heart surgery in cooperation with an extracorporeal blood circuit employing a heart/lung machine, comprising:

• (a) a conduit diverting a portion of the blood flow from the heart/lung machine to the cardioplegia delivery line;
• (b) a heat exchanger for adjusting fluid temperature in the cardioplegia delivery line;
• (c) a first pump for combining the blood from the conduit with the second fluid and delivering the combined flow into the delivery line leading to the heat exchanger;
• (d) a second pump for delivering the third fluid into the delivery line at a flow rate less than 10% of the flow rate of the combined output of the first pump;
• and
• (e) control means for adjusting the ratio of blood and second fluid delivered by the first pump, and for adjusting the total volumetric rate of flow from the first pump, and for controlling the operation of the second pump so that the volumetric rate of flow of the third fluid is maintained at a selected percentage of the flow rate from the first pump.

A cardioplegia system for delivering cardioplegic solution comprising blood and at least a second fluid to the heart through a cardioplegia line during open heart surgery in cooperation with an extracorporeal blood circuit employing a heart/lung machine, comprising:

• (a) a conduit diverting a portion of the blood flow from the heart/lung machine to the cardioplegia delivery line;
• (b) a heat exchanger for controlling fluid temperature in the cardioplegia delivery line;
• (c) a pump in the delivery line upstream from the heat exchange for accurately delivering a plurality of fluids in selected ratios, comprising:
• (i) at least one pumping chamber;
• (ii) drive means for altering the volume of the pumping chamber;
• (iii) a first valved inlet for conveying blood from the conduit to the pumping chamber;
• (iv) a second valved inlet for conveying the second fluid to the pumping chamber;
• (v) a valved outlet for conveying fluid from the pumping chamber toward the heat exchanger;
• and
• (vi) control means for the drive means, the inlets and the outlet for admitting said blood and second fluid to the pumping chamber for delivery to the outlet in a selected ratio, whereby the control means may be adjusted to vary the ratio of blood and second fluid delivered through the outlet.

A cardioplegia system for delivering cardioplegic solution comprising blood and at least a second fluid to the heart through a cardioplegia delivery line during open heart surgery in cooperation with an extracorporeal blood circuit employing a heart/lung machine, comprising:

• (a) a conduit diverting a portion of the blood flow from the heart/lung machine to the cardioplegia delivery line;
• (b) a heat exchanger for controlling fluid temperature in the cardioplegia delivery line;
• (c) a pump for receiving the blood from the conduit and the second fluid and forwarding the combined flow through the heat exchanger, the pump comprising:
• (i) an inlet;
• (ii) an outlet;
• (iii) a first pumping bladder between the inlet and the outlet;
• (iv) a second pumping bladder in parallel with the first pumping bladder;
• (v) a first drive for changing the volume of the first bladder;
• (vi) a second drive for changing the volume of the second bladder;
• (vii) valve means controlling fluid communication between the inlet and each of the bladders, and between each of the bladders and the outlet;
• and
• (viii) control means for controlling the valve means and the first and second drives so that, at first times, the first drive is reducing the first bladder volume and forcing fluid therefrom through the outlet and the second drive is expanding the volume of the second bladder so that fluid is filling the bladder from the inlet, and, at second times, the second drive is reducing the second bladder volume and forcing fluid therefrom through the outlet and the first drive is expanding the volume of the first bladder so that fluid is filling the bladder from the inlet.